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  • 1701.
    Xia, Yuxin
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska fakulteten. Jinan University, Peoples R China.
    Musumeci, Chiara
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Bergqvist, Jonas
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Ma, Wei
    Xi An Jiao Tong University, Peoples R China.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Tang, Zheng
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska fakulteten.
    Bai, Sai
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Jin, Yizheng
    Zhejiang University, Peoples R China.
    Zhu, Chenhui
    University of Calif Berkeley, CA 94720 USA.
    Kroon, Renee
    Zhejiang University, Peoples R China.
    Wang, Cheng
    University of Calif Berkeley, CA 94720 USA.
    Andersson, Mats R.
    University of S Australia, Australia.
    Hou, Lintao
    Jinan University, Peoples R China.
    Inganäs, Olle
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Wang, Ergang
    Chalmers, Sweden.
    Inverted all-polymer solar cells based on a quinoxaline-thiophene/naphthalene-diimide polymer blend improved by annealing2016Ingår i: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 4, nr 10, s. 3835-3843Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We have investigated the effect of thermal annealing on the photovoltaic parameters of all-polymer solar cells based on a quinoxaline-thiophene donor polymer (TQ1) and a naphthalene diimide acceptor polymer (N2200). The annealed devices show a doubled power conversion efficiency compared to nonannealed devices, due to the higher short-circuit current (J(sc)) and fill factor (FF), but with a lower open circuit voltage (V-oc). On the basis of the morphology-mobility examination by several scanning force microscopy techniques, and by grazing-incidence wide-angle X-ray scattering, we conclude that better charge transport is achieved by higher order and better interconnected networks of the bulk heterojunction in the annealed active layers. The annealing improves charge transport and extends the conjugation length of the polymers, which do help in charge generation and meanwhile reduce recombination. Photoluminescence, electroluminescence, and light intensity dependence measurements reveal how this morphological change affects charge generation and recombination. As a result, the J(sc) and FF are significantly improved. However, the smaller band gap and the higher HOMO level of TQ1 upon annealing causes a lower V-oc. The blend of an amorphous polymer TQ1, and a semi-crystalline polymer N2200, can thus be modified by thermal annealing to double the power conversion efficiency.

  • 1702.
    Xiao, Hui
    et al.
    Univ Cambridge, England.
    Bartoszek, Krzysztof
    Linköpings universitet, Institutionen för datavetenskap, Statistik och maskininlärning. Linköpings universitet, Filosofiska fakulteten.
    Lio, Pietro
    Univ Cambridge, England.
    Multi-omic analysis of signalling factors in inflammatory comorbidities2018Ingår i: BMC Bioinformatics, ISSN 1471-2105, E-ISSN 1471-2105, Vol. 19, artikel-id 439Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    BackgroundInflammation is a core element of many different, systemic and chronic diseases that usually involve an important autoimmune component. The clinical phase of inflammatory diseases is often the culmination of a long series of pathologic events that started years before. The systemic characteristics and related mechanisms could be investigated through the multi-omic comparative analysis of many inflammatory diseases. Therefore, it is important to use molecular data to study the genesis of the diseases. Here we propose a new methodology to study the relationships between inflammatory diseases and signalling molecules whose dysregulation at molecular levels could lead to systemic pathological events observed in inflammatory diseases.ResultsWe first perform an exploratory analysis of gene expression data of a number of diseases that involve a strong inflammatory component. The comparison of gene expression between disease and healthy samples reveals the importance of members of gene families coding for signalling factors. Next, we focus on interested signalling gene families and a subset of inflammation related diseases with multi-omic features including both gene expression and DNA methylation. We introduce a phylogenetic-based multi-omic method to study the relationships between multi-omic features of inflammation related diseases by integrating gene expression, DNA methylation through sequence based phylogeny of the signalling gene families. The models of adaptations between gene expression and DNA methylation can be inferred from pre-estimated evolutionary relationship of a gene family. Members of the gene family whose expression or methylation levels significantly deviate from the model are considered as the potential disease associated genes.ConclusionsApplying the methodology to four gene families (the chemokine receptor family, the TNF receptor family, the TGF- gene family, the IL-17 gene family) in nine inflammation related diseases, we identify disease associated genes which exhibit significant dysregulation in gene expression or DNA methylation in the inflammation related diseases, which provides clues for functional associations between the diseases.

  • 1703.
    Xuereb, Amanda
    et al.
    Univ Toronto, Canada.
    Kimber, Christopher
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Curtis, Janelle M. R.
    Fisheries and Oceans Canada, Canada.
    Bernatchez, Louis
    Univ Laval, Canada.
    Fortin, Marie-Josee
    Univ Toronto, Canada.
    Putatively adaptive genetic variation in the giant California sea cucumber (Parastichopus californicus) as revealed by environmental association analysis of restriction-site associated DNA sequencing data2018Ingår i: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 27, nr 24, s. 5035-5048Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Understanding the spatial scale of local adaptation and the factors associated with adaptive diversity are important objectives for ecology and evolutionary biology, and have significant implications for effective conservation and management of wild populations and natural resources. In this study, we used an environmental association analysis to identify important bioclimatic variables correlated with putatively adaptive genetic variation in a benthic marine invertebrate-the giant California sea cucumber (Parastichopus californicus)-spanning coastal British Columbia and southeastern Alaska. We used a redundancy analysis (RDA) with 3,699 single nucleotide polymorphisms (SNPs) obtained using RAD sequencing to detect candidate markers associated with 11 bioclimatic variables, including sea bottom and surface conditions, across two spatial scales (entire study area and within subregions). At the broadest scale, RDA revealed 59 candidate SNPs, 86% of which were associated with mean bottom temperature. Similar patterns were identified when population structure was accounted for. Additive polygenic scores, which provide a measure of the cumulative signal across all candidate SNPs, were strongly correlated with mean bottom temperature, consistent with spatially varying selection across a thermal gradient. At a finer scale, 23 candidate SNPs were detected, primarily associated with surface salinity (26%) and bottom current velocity (17%). Our findings suggest that environmental variables may play a role as drivers of spatially varying selection for P. californicus. These results provide context for future studies to evaluate the genetic basis of local adaptation in P. californicus and help inform the relevant scales and environmental variables for in situ field studies of putative adaptive variation in marine invertebrates.

  • 1704.
    Yaghmaeian Salmani, Behzad
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Monedero Cobeta, Ignacio
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Rakar, Jonathan
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Bauer, Susanne
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Rodriguez Curt, Jesús
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Starkenberg, Annika
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Thor, Stefan
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Evolutionarily conserved anterior expansion of the central nervous system promoted by a common PcG-Hox program2018Ingår i: Development, ISSN 0950-1991, E-ISSN 1477-9129, Vol. 145, nr 7, artikel-id dev160747Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A conserved feature of the central nervous system (CNS) is the prominent expansion of anterior regions (brain) compared with posterior (nerve cord). The cellular and regulatory processes driving anterior CNS expansion are not well understood in any bilaterian species. Here, we address this expansion in Drosophila and mouse. We find that, compared with the nerve cord, the brain displays extended progenitor proliferation, more elaborate daughter cell proliferation and more rapid cell cycle speed in both Drosophila and mouse. These features contribute to anterior CNS expansion in both species. With respect to genetic control, enhanced brain proliferation is severely reduced by ectopic Hox gene expression, by either Hox misexpression or by loss of Polycomb group (PcG) function. Strikingly, in PcG mutants, early CNS proliferation appears to be unaffected, whereas subsequent brain proliferation is severely reduced. Hence, a conserved PcG-Hox program promotes the anterior expansion of the CNS. The profound differences in proliferation and in the underlying genetic mechanisms between brain and nerve cord lend support to the emerging concept of separate evolutionary origins of these two CNS regions.

  • 1705.
    Yakymenko Alkaissi, Lina
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för Kirurgi, Ortopedi och Onkologi. Linköpings universitet, Medicinska fakulteten.
    Bacterial epithelial interaction in intestinal inflammation2018Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The intestine is constantly exposed to bacteria, invading viruses and ingested food. The intestinal barrier serves as a gate preventing passage of harmful components, and at the same time maintaining absorption of nutrients and water. There are over 300 different bacteria species in the human gastrointestinal tract (GI) comprising over 10 times as many cells as the human body. These bacteria are both of commensal and pathogenic strains in which commensal bacteria and antimicrobial peptides have an important role of controlling the intestinal colonization. The intestinal flora is sampled by the membranous cells (M cells) that are present in the follicle associated epithelium (FAE). Antigens encounter immune cells found in Peyer’s patches located in the distal ileum with FAE overlaying them. Due to environmental factors, genetic predisposition, immune dysregulation or dysbiosis the balance can be shifted which, in turn, will lead to the defect in the barrier function, leading to the development of disorders such as Crohn’s disease (CD). CD is a chronic inflammation in the GI tract, often originating in the distal ileum in FAE and associated with an increased number of adherent invasive strains of bacteria. Specifically adherent invasive E.coli (AIEC) that have been isolated from the ileum and colon of CD patients.

    The aim of the present thesis was to study bacterial epithelial interaction during inflammation in in vivo, ex vivo and in vitro models.

    In the first project we found that that Faecalibacterium prausnitzii (FP), possess anti-inflammatory properties in the ileum of an in vivo DSS induced colitis mouse model.

    In the second project, we discovered that infliximab, known to have anti-inflammatory effects by binding soluble TNF and blocking TNF receptors, reduces bacterial transcytosis across colonic biopsies of CD patients and decreases transcytosis and internalization in cell monolayers in vitro. Moreover, we demonstrated that HM427 bacteria, isolated from colonic mucosa of CD patients, uses lipid raft formations to penetrate the barrier under the influence of TNF in an in vitro model.

    In project three, we demonstrated that LF82 bacteria, which is an adherent invasive strain of E.coli that has been isolated from the ileum of CD patients, exploits FAE of CD patients and non-IBD control patients to penetrate the barrier via the CEACAM6 receptor and long polar fimbriae. We further demonstrated that there is an increased expression of CEACM6 receptor in the FAE of CD patients, which leads to increased transcytosis of LF82 compared to non-IBD control group.

    In project four, our results suggested that human α-defensin 5 significantly decreases the passage of LF82 bacteria in an in vitro and ex vivo models. Moreover, we demonstrated that CD patients have a lower expression of human α-defensin 5 in the crypts compared to the non-IBD control patients.

    Taken together, our findings have given a novel insight into the etiology of CD and into the mechanisms involved in bacterial-epithelial interaction in CD.

    Delarbeten
    1. Faecalibacterium prausnitzii supernatant improves intestinal barrier function in mice DSS colitis
    Öppna denna publikation i ny flik eller fönster >>Faecalibacterium prausnitzii supernatant improves intestinal barrier function in mice DSS colitis
    Visa övriga...
    2013 (Engelska)Ingår i: Scandinavian Journal of Gastroenterology, ISSN 0036-5521, E-ISSN 1502-7708, Vol. 48, nr 10, s. 1136-1144Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Objective. The intestinal microbiota plays a substantial role in the pathogenesis of inflammatory bowel disease (IBD). Faecalibacterium prausnitzii (FP) is underrepresented in IBD patients and have been suggested to have anti-inflammatory effects in mice. Increased intestinal permeability is common in IBD but the relationship between FP and intestinal barrier function has not been investigated. Our aim was to study treatment with FP supernatant on intestinal barrier function in a dextran sodium sulfate (DSS) colitis mice model. Material and methods. C57BL/6 mice received 3% DSS in tap water ad libitum during five days to induce colitis. From day 3 the mice received a daily gavage with FP supernatant or broth during seven days. Ileum and colon were mounted in Ussing chambers for permeability studies with Cr-51-EDTA and Escherichia coli K-12. Colon was saved for Western blot analyses of tight junction proteins. Results. DSS-treated mice showed significant weight loss and colon shortening. Gavage with FP supernatant resulted in a quicker recovery after DSS treatment and less extensive colonic shortening. Ileal mucosa of DSS mice showed a significant increase in Cr-51-EDTA-passage compared to controls. Cr-51-EDTA passage was significantly decreased in mice receiving FP supernatant. No significant differences were observed in passage of E. coli K12. Western blots showed a trend to increased claudin-1 and claudin-2 expressions in DSS mice. Conclusions. Supernatant of FP enhances the intestinal barrier function by affecting paracellular permeability, and may thereby attenuate the severity of DSS-induced colitis in mice. These findings suggest a potential role of FP in the treatment of IBD.

    Ort, förlag, år, upplaga, sidor
    Informa Healthcare, 2013
    Nyckelord
    dextran sodium sulfate, inflammatory bowel disease, permeability, probiotics, tight junctions
    Nationell ämneskategori
    Teknik och teknologier
    Identifikatorer
    urn:nbn:se:liu:diva-99406 (URN)10.3109/00365521.2013.828773 (DOI)000324761000005 ()
    Anmärkning

    Funding Agencies|Swedish Research Council|VR-M: K2012-55X-12618-16-3|

    Tillgänglig från: 2013-10-17 Skapad: 2013-10-17 Senast uppdaterad: 2018-04-27
    2. Infliximab restores colonic barrier to adherent-invasive E. coli in Crohn's disease via effects on epithelial lipid rafts
    Öppna denna publikation i ny flik eller fönster >>Infliximab restores colonic barrier to adherent-invasive E. coli in Crohn's disease via effects on epithelial lipid rafts
    Visa övriga...
    2018 (Engelska)Ingår i: Scandinavian Journal of Gastroenterology, ISSN 0036-5521, E-ISSN 1502-7708, Vol. 53, nr 6, s. 677-684Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Objective: Infliximab is important in the therapeutic arsenal of Crohn’s disease (CD). However, its effect on mucosal barrier function is not fully understood. Adherent-invasive Escherichia coli (AIEC) are important in CD pathophysiology, but the transmucosal uptake routes are partly unknown. We investigated effects of infliximab on uptake of colon-specific AIEC HM427 across CD colonic mucosa.

    Materials and methods: Endoscopic biopsies from non-inflamed colon of seven patients with CD, before and after two infliximab infusions, and eight non-inflammation controls, were mounted in Ussing chambers. Paracellular permeability (51Cr-EDTA) and transmucosal passage of GFP-expressing HM427 were studied. Mechanisms of HM427 transepithelial transport were investigated in Caco-2 monolayers treated with TNF, in the presence of infliximab and/or endocytosis inhibitors.

    Results: Before infliximab treatment, colonic passage of HM427 [CD: 2475 CFU (450–3000); controls 1163(225–1950)] and 51Cr-EDTA permeability were increased in CD (p < .05), but were restored to control levels by infliximab (CD: 150 (18.8–1069)). In TNF-exposed Caco-2 monolayers HM427 transport and lipid rafts/HM427 co-localization was decreased by infliximab. The lipid raft inhibitor methyl-β-cyclodextrin decreased HM427 transport.

    Conclusion: Infliximab restored the colonic barrier to AIEC in CD; an effect partially mediated by blocking lipid rafts in epithelial cells. This ability likely contributes to infliximab’s clinical efficacy in colonic CD.

    Ort, förlag, år, upplaga, sidor
    Taylor & Francis, 2018
    Nyckelord
    Inflammatory bowel disease, microbiology, large intestine, intestinal barrier function, adherent invasive E. coli
    Nationell ämneskategori
    Gastroenterologi
    Identifikatorer
    urn:nbn:se:liu:diva-147615 (URN)10.1080/00365521.2018.1458146 (DOI)000438146900008 ()29688802 (PubMedID)
    Anmärkning

    Funding agencies: Swedish Research Council-Medicine [VR-MH 2014-02537]; ALF Grants Region Ostergotland

    Tillgänglig från: 2018-04-27 Skapad: 2018-04-27 Senast uppdaterad: 2019-04-30Bibliografiskt granskad
  • 1706.
    Yamashita, Tetsuji
    et al.
    St. Jude Children’s Research Hospital, Memphis, Tennessee, United States of America.
    Hakizimana, Pierre
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för neuro- och inflammationsvetenskap. Linköpings universitet, Medicinska fakulteten. Karolinska Institutet, Stockholm, Sweden; Karolinska University Hospital, Stockholm, Sweden.
    Wu, Siva
    Lawrence Berkeley National Laboratory, Berkeley, California, United States of America.
    Hassan, Ahmed
    Lawrence Berkeley National Laboratory, Berkeley, California, United States of America.
    Jacob, Stefan
    Karolinska Institutet, Stockholm, Sweden.
    Temirov, Jamshid
    St. Jude Children’s Research Hospital, Memphis, Tennessee, United States of America.
    Fang, Jie
    St. Jude Children’s Research Hospital, Memphis, Tennessee, United States of America.
    Mellado-Lagarde, Marcia
    St. Jude Children’s Research Hospital, Memphis, Tennessee, United States of America; University of Brigthon, Brighton, United Kingdom.
    Gursky, Richard
    St. Jude Children’s Research Hospital, Memphis, Tennessee, United States of America.
    Horner, Linda
    St. Jude Children’s Research Hospital, Memphis, Tennessee, United States of America.
    Leibiger, Barbara
    Karolinska Institutet, Stockholm, Sweden.
    Leijon, Sara
    Karolinska Institutet, Stockholm, Sweden.
    Centonze, Victoria E
    St. Jude Children’s Research Hospital, Memphis, Tennessee, United States of America.
    Berggren, Per-Olof
    Karolinska Institutet, Stockholm, Sweden.
    Frase, Sharon
    St. Jude Children’s Research Hospital, Memphis, Tennessee, United States of America.
    Auer, Manfred
    Lawrence Berkeley National Laboratory, Berkeley, California,United States of America.
    Brownell, William E
    Baylor College of Medicine, Houston, Texas, United States of America.
    Fridberger, Anders
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för cellbiologi. Linköpings universitet, Medicinska fakulteten. Karolinska Institutet, Stockholm, Sweden; Karolinska University Hospital, Stockholm, Sweden.
    Zuo, Jian
    St. Jude Children’s Research Hospital, Memphis, Tennessee, United States of America.
    Outer Hair Cell Lateral Wall Structure Constrains the Mobility of Plasma Membrane Proteins2015Ingår i: PLOS Genetics, ISSN 1553-7390, E-ISSN 1553-7404, Vol. 11, nr 9, artikel-id e1005500Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Nature's fastest motors are the cochlear outer hair cells (OHCs). These sensory cells use a membrane protein, Slc26a5 (prestin), to generate mechanical force at high frequencies, which is essential for explaining the exquisite hearing sensitivity of mammalian ears. Previous studies suggest that Slc26a5 continuously diffuses within the membrane, but how can a freely moving motor protein effectively convey forces critical for hearing? To provide direct evidence in OHCs for freely moving Slc26a5 molecules, we created a knockin mouse where Slc26a5 is fused with YFP. These mice and four other strains expressing fluorescently labeled membrane proteins were used to examine their lateral diffusion in the OHC lateral wall. All five proteins showed minimal diffusion, but did move after pharmacological disruption of membrane-associated structures with a cholesterol-depleting agent and salicylate. Thus, our results demonstrate that OHC lateral wall structure constrains the mobility of plasma membrane proteins and that the integrity of such membrane-associated structures are critical for Slc26a5's active and structural roles. The structural constraint of membrane proteins may exemplify convergent evolution of cellular motors across species. Our findings also suggest a possible mechanism for disorders of cholesterol metabolism with hearing loss such as Niemann-Pick Type C diseases.

  • 1707.
    Yao, Xuefei
    Linköpings universitet, Institutionen för fysik, kemi och biologi.
    High Forest or Wood Pasture: A model of Large Herbivores' impact on European Lowland Vegetation2010Självständigt arbete på avancerad nivå (masterexamen), 40 poäng / 60 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Natural forest dynamics is a foundational topic of forest science. A new Wood Pasture hypothesis considering large herbivore as driving force in forest ecosystem is now challenging the traditional High Forest hypothesis, in which vegetation is regarded as main driving force. In this study, a model-based approach is applied to investigate differences between these two hypotheses and the determine factors in the system. A theoretical landscape of 1 km²formed by 100*100 cells is set up with 100 vegetation patches and free moving herbivores on. Our null hypothesis that herbivores make no difference in vegetation dynamics especially at canopy level is rejected. It is found that synchronization of herbivore behaviors is the most influencing factor of how a landscape might be shaped. It is also found that landscape could be a mosaic of both high forest and wood pasture depends on large herbivore’s herd size.

  • 1708.
    Yin, Lan
    et al.
    University of Gothenburg, Sweden.
    Vener Dödsbo, Alexander
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för cellbiologi. Linköpings universitet, Hälsouniversitetet.
    Spetea, Cornelia
    University of Gothenburg, Sweden.
    The membrane proteome of stroma thylakoids from Arabidopsis thaliana studied by successive in-solution and in-gel digestion2015Ingår i: Physiologia Plantarum: An International Journal for Plant Biology, ISSN 0031-9317, E-ISSN 1399-3054, Vol. 154, nr 3, s. 433-446Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    From individual localization and large-scale proteomic studies, we know that stroma-exposed thylakoid membranes harbor part of the machinery performing the light-dependent photosynthetic reactions. The minor components of the stroma thylakoid proteome, regulating and maintaining the photosynthetic machinery, are in the process of being unraveled. In this study, we developed in-solution and in-gel proteolytic digestion methods, and used them to identify minor membrane proteins, e.g. transporters, in stroma thylakoids prepared from Arabidopsis thaliana (L.) Heynh Columbia-0 leaves. In-solution digestion with chymotrypsin yielded the largest number of peptides, but in combination with methanol extraction resulted in identification of the largest number of membrane proteins. Although less efficient in extracting peptides, in-gel digestion with trypsin and chymotrypsin led to identification of additional proteins. We identified a total of 58 proteins including 44 membrane proteins. Almost half are known thylakoid proteins with roles in photosynthetic light reactions, proteolysis and import. The other half, including many transporters, are not known as chloroplast proteins, because they have been either curated (manually assigned) to other cellular compartments or not curated at all at the plastid protein databases. Transporters include ATP-binding cassette (ABC) proteins, transporters for K+ and other cations. Other proteins either have a role in processes probably linked to photosynthesis, namely translation, metabolism, stress and signaling or are contaminants. Our results indicate that all these proteins are present in stroma thylakoids; however, individual studies are required to validate their location and putative roles. This study also provides strategies complementary to traditional methods for identification of membrane proteins from other cellular compartments.

  • 1709.
    Yong, Yean K.
    et al.
    Xiamen Univ Malaysia, Malaysia; Univ Malaya, Malaysia; Xiamen Univ Malaysia, Malaysia.
    Saeidi, Alireza
    Univ Malaya, Malaysia.
    Tan, Hong Y.
    Xiamen Univ Malaysia, Malaysia; Univ Malaya, Malaysia; Xiamen Univ Malaysia, Malaysia; Xiamen Univ Malaysia, Malaysia.
    Rosmawati, Mohamed
    Univ Malaya, Malaysia.
    Enström, Philip F.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Al Batran, Rami
    Univ Malaya, Malaysia.
    Vasuki, V.
    Govt Thiruvarur Med Coll and Hosp, India.
    Chattopadhyay, Indranil
    Cent Univ Tamil Nadu, India.
    Murugesan, Amudhan
    Govt Theni Med Coll and Hosp, India.
    Vignesh, Ramachandran
    Univ Kuala Lumpur, Malaysia.
    Kamarulzaman, Adeeba
    Univ Malaya, Malaysia; Univ Malaya, Malaysia.
    Rajarajeswaran, Jayakumar
    Univ Malaya, Malaysia.
    Ansari, Abdul W.
    Univ Malaya, Malaysia.
    Vadivelu, Jamuna
    Univ Malaya, Malaysia.
    Ussher, James E.
    Univ Otago, New Zealand.
    Velu, Vijayakumar
    Emory Vaccine Ctr, GA USA.
    Larsson, Marie
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Shankar, Esaki M.
    Univ Malaya, Malaysia; Cent Univ Tamil Nadu, India; Cent Univ Tamil Nadu, India.
    Hyper-Expression of PD-1 Is Associated with the Levels of Exhausted and Dysfunctional Phenotypes of Circulating CD161(++)TCR iV alpha 7.2(+) Mucosal-Associated Invariant T Cells in Chronic Hepatitis B Virus Infection2018Ingår i: Frontiers in Immunology, ISSN 1664-3224, E-ISSN 1664-3224, Vol. 9, artikel-id 472Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Mucosal-associated invariant T (MAIT) cells, defined as CD161(++) TCR iV alpha 7.2(+) T cells, play an important role in the innate defense against bacterial infections, and their functionality is impaired in chronic viral infections. Here, we investigated the frequency and functional role of MAIT cells in chronic hepatitis B virus (HBV) infection. The peripheral CD3(+)CD161(++)TCR iV alpha 7.2(+) MAIT cells in chronic HBV-infected patients and healthy controls were phenotypically characterized based on CD57, PD-1, TIM-3, and CTLA-4, as well as HLA-DR and CD38 expression. The frequency of MAIT cells was significantly decreased among chronic HBV-infected individuals as compared to controls. Expression of CD57, PD-1, CTLA-4, as well as HLA-DR and CD38 on MAIT cells was significantly elevated in chronic HBV-infected individuals relative to controls. The percentage of T cell receptor (TCR) iVa7.2+ CD161(+) MAIT cells did not correlate with HBV viral load but inversely with HLA-DR on CD4(+) T cells and MAIT cells and with CD57 on CD8(+) T cells suggesting that decrease of MAIT cells may not be attributed to direct infection by HBV but driven by HBV-induced chronic immune activation. The percentage and expression levels of PD-1 as well as CTLA-4 on MAIT cells inversely correlated with plasma HBV-DNA levels, which may suggest either a role for MAIT cells in the control of HBV infection or the effect of HBV replication in the liver on MAIT cell phenotype. We report that decrease of TCR iV alpha 7.2(+) MAIT cells in the peripheral blood and their functions were seemingly impaired in chronic HBV-infected patients likely because of the increased expression of PD-1.

  • 1710.
    Younis, Shady
    et al.
    Department of Medical Biochemistry and Microbiology, Uppsala University, SE-751 23 Uppsala, Sweden // Department of Animal Production, Ain Shams University, Shoubra El-Kheima, 11241 Cairo, Egypt.
    Kamel, Wael
    Department of Medical Biochemistry and Microbiology, Uppsala University, SE-751 23 Uppsala, Sweden.
    Falkeborn, Tina
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Diagnostikcentrum, Klinisk mikrobiologi.
    Wang, Hao
    Department of Biochemistry and Biophysics, Stockholm University, SE-10691 Stockholm, Sweden.
    Yu, Di
    Department of Immunology, Genetics and Pathology, Uppsala University, SE-751 23 Uppsala, Sweden.
    Daniels, Robert
    Department of Biochemistry and Biophysics, Stockholm University, SE-10691 Stockholm, Sweden.
    Essand, Magnus
    Department of Immunology, Genetics and Pathology, Uppsala University, SE-751 23 Uppsala, Sweden.
    Hinkula, Jorma
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten. Department of Microbiology Tumor and Cell Biology, Karolinska Institutet, 17177 Stockholm, Sweden.
    Akusjärvi, Göran
    Department of Medical Biochemistry and Microbiology, Uppsala University, SE-751 23 Uppsala, Sweden.
    Andersson, Leif
    Department of Medical Biochemistry and Microbiology, Uppsala University, SE-751 23 Uppsala, Sweden // Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, SE-75007 Uppsala, Sweden // Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX 77483, USA.
    Multiple nuclear-replicating viruses require the stress-induced protein ZC3H11A for efficient growth2018Ingår i: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 115, nr 6, s. E3808-E3816Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The zinc finger CCCH-type containing 11A (ZC3H11A) gene encodes a well-conserved zinc finger protein that may function in mRNA export as it has been shown to associate with the transcription export (TREX) complex in proteomic screens. Here, we report that ZC3H11A is a stress-induced nuclear protein with RNA-binding capacity that localizes to nuclear splicing speckles. During an adenovirus infection, the ZC3H11A protein and splicing factor SRSF2 relocalize to nuclear regions where viral DNA replication and transcription take place. Knockout (KO) of ZC3H11A in HeLa cells demonstrated that several nuclear-replicating viruses are dependent on ZC3H11A for efficient growth (HIV, influenza virus, herpes simplex virus, and adenovirus), whereas cytoplasmic replicating viruses are not (vaccinia virus and Semliki Forest virus). High-throughput sequencing of ZC3H11A–cross-linked RNA showed that ZC3H11A binds to short purine-rich ribonucleotide stretches in cellular and adenoviral transcripts. We show that the RNA-binding property of ZC3H11A is crucial for its function and localization. In ZC3H11A KO cells, the adenovirus fiber mRNA accumulates in the cell nucleus. Our results suggest that ZC3H11A is important for maintaining nuclear export of mRNAs during stress and that several nuclear-replicating viruses take advantage of this mechanism to facilitate their replication.

  • 1711.
    Yuan, Jun
    et al.
    Univ Calif Los Angeles, CA 90095 USA; Cent S Univ, Peoples R China; Univ Calif Los Angeles, CA 90095 USA.
    Huang, Tianyi
    Univ Calif Los Angeles, CA 90095 USA.
    Cheng, Pei
    Univ Calif Los Angeles, CA 90095 USA.
    Zou, Yingping
    Cent S Univ, Peoples R China.
    Zhang, Huotian
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Yang, Jonathan Lee
    Univ Calif Berkeley, CA 94720 USA.
    Chang, Sheng-Yung
    Univ Calif Los Angeles, CA 90095 USA.
    Zhang, Zhenzhen
    Cent S Univ, Peoples R China.
    Huang, Wenchao
    Univ Calif Los Angeles, CA 90095 USA.
    Wang, Rui
    Univ Calif Los Angeles, CA 90095 USA.
    Meng, Dong
    Univ Calif Los Angeles, CA 90095 USA; Univ Calif Los Angeles, CA 90095 USA.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Yang, Yang
    Univ Calif Los Angeles, CA 90095 USA.
    Enabling low voltage losses and high photocurrent in fullerene-free organic photovoltaics (vol 10, 570, 2019)2019Ingår i: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 10, artikel-id 1624Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    n/a

  • 1712.
    Yusifov, Taleh
    et al.
    Division of Molecular Medicine, Department of Anesthesiology, David Geffen School of Medicine at University of California, Los Angeles, USA.
    Javaherian, Anoosh D.
    Division of Molecular Medicine, Department of Anesthesiology, David Geffen School of Medicine at University of California, Los Angeles, USA.
    Pantazis, Antonios
    Division of Molecular Medicine, Department of Anesthesiology, David Geffen School of Medicine at University of California, Los Angeles, USA.
    Gandhi, Chris S.
    Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, USA.
    Olcese, Olcese
    Division of Molecular Medicine, Department of Anesthesiology, Cardiovascular Research Laboratory, and Brain Research Institute, David Geffen School of Medicine at University of California, Los Angeles, USA.
    The RCK1 Domain of the Human BKCa Channel Transduces Ca2+ Binding into Structural Rearrangements2010Ingår i: The Journal of General Physiology, ISSN 0022-1295, E-ISSN 1540-7748, Vol. 136, nr 2, s. 189-202Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Large-conductance voltage- and Ca2+-activated K+ (BKCa) channels play a fundamental role in cellular function by integrating information from their voltage and Ca2+ sensors to control membrane potential and Ca2+ homeostasis. The molecular mechanism of Ca2+-dependent regulation of BKCa channels is unknown, but likely relies on the operation of two cytosolic domains, regulator of K+ conductance (RCK)1 and RCK2. Using solution-based investigations, we demonstrate that the purified BKCa RCK1 domain adopts an α/β fold, binds Ca2+, and assembles into an octameric superstructure similar to prokaryotic RCK domains. Results from steady-state and time-resolved spectroscopy reveal Ca2+-induced conformational changes in physiologically relevant [Ca2+]. The neutralization of residues known to be involved in high-affinity Ca2+ sensing (D362 and D367) prevented Ca2+-induced structural transitions in RCK1 but did not abolish Ca2+ binding. We provide evidence that the RCK1 domain is a high-affinity Ca2+ sensor that transduces Ca2+ binding into structural rearrangements, likely representing elementary steps in the Ca2+-dependent activation of human BKCa channels.

  • 1713.
    Zaidon, Nuradawiyah
    et al.
    Int Islamic Univ, Malaysia.
    Mansor, Ahmad Fairuzabadi Mohd
    Int Islamic Univ, Malaysia.
    Mak, Wing Cheung
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Sensor- och aktuatorsystem. Linköpings universitet, Tekniska fakulteten.
    Ismail, Ahmad Faris
    Int Islamic Univ, Malaysia.
    Nordin, Anis Nurashikin
    Int Islamic Univ, Malaysia.
    Microfluidic Concentration Gradient for Toxicity Studies of Lung Carcinoma Cells2017Ingår i: BIOSENSORS 2016, ELSEVIER SCIENCE BV , 2017, Vol. 27, s. 153-154Konferensbidrag (Refereegranskat)
    Abstract [en]

    n/a

  • 1714.
    Zajdel, Joanna
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Centrum för social och affektiv neurovetenskap. Linköpings universitet, Medicinska fakulteten.
    Interactions between the brain and the immune system in pain and inflammation2019Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Reciprocal interactions between the nervous and immune systems have gained a lot of attention in the last two decades, especially after demonstrating that cytokine immunotherapies can induce depression and after describing the inflammatory reflex. A lot of effort has been dedicated to understanding how the signals from the immune system reach the brain and vice versa, and on their role in health and disease. However, it is not well-known which of the brain circuits, receptors and signalling molecules give rise to behavioural and affective changes induced by inflammation, such as reduced food intake and induction of negative mood. Moreover, although it is well established that early life stress leads to an increased risk of developing inflammatory diseases in adulthood, the acute effects of stress on the inflammatory response in childhood are not well described. Using mouse models of systemic and local inflammation, I studied (1) how inflammatory pain elicits negative affect, (2) if CGRPα is necessary for parabrachial-amygdaloid pathway-mediated behaviours associated with pain and inflammation, and finally, (3) what are the effects of stress on the inflammatory process during early life. The results indicate that (1) the negative affect of inflammatory pain is triggered by inhibition of serotonergic neurons of the dorsal raphe nucleus, as a result of prostaglandin E2 binding to EP3 receptors; (2) CGRPα is dispensable for most pain- and inflammation-related protective behaviours; (3) acute stress potentiates the pro-inflammatory cytokine expression after an inflammatory challenge in mouse pups. The phenomena studied here can contribute to understanding how immune system activation induces changes in mood and behaviour common for inflammation and depression.

    Delarbeten
    1. Prostaglandin-mediated inhibition of serotonin signaling controls the affective component of inflammatory pain
    Öppna denna publikation i ny flik eller fönster >>Prostaglandin-mediated inhibition of serotonin signaling controls the affective component of inflammatory pain
    Visa övriga...
    2017 (Engelska)Ingår i: Journal of Clinical Investigation, ISSN 0021-9738, E-ISSN 1558-8238, Vol. 127, nr 4, s. 1370-1374Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Pain is fundamentally unpleasant and induces a negative affective state. The affective component of pain is mediated by circuits that are distinct from those mediating the sensory-discriminative component. Here, we have investigated the role of prostaglandins in the affective dimension of pain using a rodent pain assay based on conditioned place aversion to formalin injection, an inflammatory noxious stimulus. We found that place aversion induced by inflammatory pain depends on prostaglandin E-2 that is synthesized by cyclooxygenase 2 in neural cells. Further, mice lacking the prostaglandin E-2 receptor EP3 selectively on serotonergic cells or selectively in the area of the dorsal raphe nucleus failed to form an aversion to formalininduced pain, as did mice lacking the serotonin transporter. Chemogenetic manipulations revealed that EP3 receptor activation elicited conditioned place aversion to pain via inhibition of serotonergic neurons. In contrast to their role in inflammatory pain aversion, EP3 receptors on serotonergic cells were dispensable for acute nociceptive behaviors and for aversion induced by thermal pain or a kappa opioid receptor agonist. Collectively, our findings show that prostaglandin-mediated modulation of serotonergic transmission controls the affective component of inflammatory pain.

    Ort, förlag, år, upplaga, sidor
    AMER SOC CLINICAL INVESTIGATION INC, 2017
    Nationell ämneskategori
    Neurovetenskaper
    Identifikatorer
    urn:nbn:se:liu:diva-136568 (URN)10.1172/JCI90678 (DOI)000398183300026 ()28287401 (PubMedID)
    Anmärkning

    Funding Agencies|European Research Council; Swedish Medical Research Council; Knut and Alice Wallenberg Foundation; Swedish Brain Foundation; County Council of Ostergotland; National Institute of Neurological Disorders and Stroke (NINDS)

    Tillgänglig från: 2017-04-24 Skapad: 2017-04-24 Senast uppdaterad: 2019-04-08
    2. Acute maternal separation potentiates the gene expression and corticosterone response induced by inflammation
    Öppna denna publikation i ny flik eller fönster >>Acute maternal separation potentiates the gene expression and corticosterone response induced by inflammation
    Visa övriga...
    2019 (Engelska)Ingår i: Brain, behavior, and immunity, ISSN 0889-1591, E-ISSN 1090-2139, Vol. 77, s. 141-149Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Maternal care is crucial for infants and profoundly affects their responses to different kinds of stressors. Here, we examined how maternal separation affects inflammatory gene expression and the corticosterone response to an acute immune challenge induced by lipopolysaccharide (LPS; 40 µg/kg ip) in mouse pups, 8–9 days old. Maternal separation initially attenuated LPS-induced hypothalamic pro-inflammatory gene expression, but later, at 3 h after immune challenge, robustly augmented such gene expression and increased serum corticosterone levels. Providing the pups with a warm and soft object prevented the separation-induced augmented hypothalamic-pituitary-adrenal (HPA)-axis response. It also prevented the potentiated induction of some, but not all, inflammatory genes to a similar extent as did the dam. Our results show that maternal separation potentiates the inflammatory response and the resulting HPA-axis activation, which may have detrimental effects if separation is prolonged or repeated.

    Ort, förlag, år, upplaga, sidor
    Elsevier, 2019
    Nyckelord
    Lipopolysaccharide, Hypothalamus, Cytokines, Inflammation, Maternal separation, Corticosterone
    Nationell ämneskategori
    Farmakologi och toxikologi Utvecklingsbiologi Medicinsk bioteknologi Immunologi
    Identifikatorer
    urn:nbn:se:liu:diva-154886 (URN)10.1016/j.bbi.2018.12.016 (DOI)30590109 (PubMedID)2-s2.0-85059128986 (Scopus ID)
    Tillgänglig från: 2019-03-04 Skapad: 2019-03-04 Senast uppdaterad: 2019-04-08Bibliografiskt granskad
  • 1715.
    Zajdel, Joanna
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Centrum för social och affektiv neurovetenskap. Linköpings universitet, Medicinska fakulteten.
    Zager, Adriano
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelning för neurobiologi. Linköpings universitet, Medicinska fakulteten.
    Blomqvist, Anders
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelning för neurobiologi. Linköpings universitet, Medicinska fakulteten.
    Engblom, David
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Centrum för social och affektiv neurovetenskap. Linköpings universitet, Medicinska fakulteten.
    Shionoya, Kiseko
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelning för neurobiologi. Linköpings universitet, Medicinska fakulteten.
    Acute maternal separation potentiates the gene expression and corticosterone response induced by inflammation2019Ingår i: Brain, behavior, and immunity, ISSN 0889-1591, E-ISSN 1090-2139, Vol. 77, s. 141-149Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Maternal care is crucial for infants and profoundly affects their responses to different kinds of stressors. Here, we examined how maternal separation affects inflammatory gene expression and the corticosterone response to an acute immune challenge induced by lipopolysaccharide (LPS; 40 µg/kg ip) in mouse pups, 8–9 days old. Maternal separation initially attenuated LPS-induced hypothalamic pro-inflammatory gene expression, but later, at 3 h after immune challenge, robustly augmented such gene expression and increased serum corticosterone levels. Providing the pups with a warm and soft object prevented the separation-induced augmented hypothalamic-pituitary-adrenal (HPA)-axis response. It also prevented the potentiated induction of some, but not all, inflammatory genes to a similar extent as did the dam. Our results show that maternal separation potentiates the inflammatory response and the resulting HPA-axis activation, which may have detrimental effects if separation is prolonged or repeated.

  • 1716.
    Zajitschek, Felix
    et al.
    Monash Univ, Australia; Uppsala Univ, Sweden.
    Georgolopoulos, Grigorios
    Uppsala Univ, Sweden.
    Vourlou, Anna
    Uppsala Univ, Sweden.
    Ericsson, Maja
    Uppsala Univ, Sweden.
    Zajitschek, Susanne R. K.
    Monash Univ, Australia; CSIC, Spain; Uppsala Univ, Sweden.
    Friberg, Urban
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten. Uppsala Univ, Sweden.
    Maklakov, Alexei A.
    Uppsala Univ, Sweden; Univ East Anglia, England.
    Evolution Under Dietary Restriction Decouples Survival From Fecundity in Drosophila melanogaster Females2019Ingår i: The journals of gerontology. Series A, Biological sciences and medical sciences, ISSN 1079-5006, E-ISSN 1758-535X, Vol. 74, nr 10, s. 1542-1548Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    One of the key tenets of life-history theory is that reproduction and survival are linked and that they trade-off with each other. When dietary resources are limited, reduced reproduction with a concomitant increase in survival is commonly observed. It is often hypothesized that this dietary restriction effect results from strategically reduced investment in reproduction in favor of somatic maintenance to survive starvation periods until resources become plentiful again. We used experimental evolution to test this "waiting-for-the-good-times" hypothesis, which predicts that selection under sustained dietary restriction will favor increased investment in reproduction at the cost of survival because "good-times" never come. We assayed fecundity and survival of female Drosophila melanogaster fruit flies that had evolved for 50 generations on three different diets varying in protein content-low (classic dietary restriction diet), standard, and high-in a full-factorial design. High-diet females evolved overall increased fecundity but showed reduced survival on low and standard diets. Low-diet females evolved reduced survival on low diet without corresponding increase in reproduction. In general, there was little correspondence between the evolution of survival and fecundity across all dietary regimes. Our results contradict the hypothesis that resource reallocation between fecundity and somatic maintenance underpins life span extension under dietary restriction.

  • 1717.
    Zajitschek, Felix
    et al.
    Monash University, Australia; Uppsala University, Sweden.
    Zajitschek, Susanne R. K.
    Uppsala University, Sweden; Spanish Research Council CSIC, Spain.
    Canton, Cindy
    Uppsala University, Sweden.
    Georgolopoulos, Grigorios
    Uppsala University, Sweden.
    Friberg, Urban
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten. Uppsala University, Sweden.
    Maklakov, Alexei A.
    Uppsala University, Sweden.
    Evolution under dietary restriction increases male reproductive performance without survival cost2016Ingår i: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 283, nr 1825, s. 20152726-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Dietary restriction (DR), a reduction in nutrient intake without malnutrition, is the most reproducible way to extend lifespan in a wide range of organisms across the tree of life, yet the evolutionary underpinnings of the DR effect on lifespan are still widely debated. The leading theory suggests that this effect is adaptive and results from reallocation of resources from reproduction to somatic maintenance, in order to survive periods of famine in nature. However, such response would cease to be adaptive when DR is chronic and animals are selected to allocate more resources to reproduction. Nevertheless, chronic DR can also increase the strength of selection resulting in the evolution of more robust genotypes. We evolved Drosophila melanogaster fruit flies on DR, standard and high adult diets in replicate populations with overlapping generations. After approximately 25 generations of experimental evolution, male DR flies had higher fitness than males from standard and high populations. Strikingly, this increase in reproductive success did not come at a cost to survival. Our results suggest that sustained DR selects for more robust male genotypes that are overall better in converting resources into energy, which they allocate mostly to reproduction.

  • 1718.
    Zajitschek, Felix
    et al.
    Department of Animal Ecology, Ageing Research Group, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden.
    Zajitschek, Susanne R. K.
    Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden.
    Friberg, Urban
    Department of Evolutionary Biology, Ageing Research Group, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden.
    Maklakov, Alexei A.
    Department of Animal Ecology, Ageing Research Group, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden.
    Interactive effects of sex, social environment, dietary restriction, and methionine on survival and reproduction in fruit flies2013Ingår i: Age (Omaha), ISSN 0161-9152, E-ISSN 1574-4647, Vol. 35, nr 4, s. 1193-1204Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    For the evolution of life histories, the trade-off between survival and reproduction is fundamental. Because sexes optimize fitness in different ways, this trade-off is expected to be resolved differently by males and females. Consequently, the sexes are predicted to respond differently to changes in resource availability. In fruit flies, research on dietary restriction has focused largely on females maintained in the absence of males, thereby neglecting sexual interactions that affect reproductive behavior of both sexes under more natural conditions. Here, we tested for the interactive effects of diet (40, 60, 100, and 300 % of standard yeast concentrations) and social environment (separate-sex vs. mixed-sex groups) on male and female Drosophila melanogaster life histories. Additionally, we evaluated the essential amino acid methionine as an agent that can uncouple the survival-reproduction trade-off. We show sex differences in the effect of social environment on survival patterns, but not on reproductive fitness. In females, yeast had a positive effect on reproduction and a negative effect on survival. In males, yeast had a negative effect on reproduction and the effect on survival depended on the social environment. Methionine reduced survival, but had no effect on reproduction. Our findings highlight the need to include both sexes and to vary social environments in research programs aimed at lifespan extension and call for further evaluation of the fecundity-restoring effect of methionine.

  • 1719.
    Zeng, Fan
    et al.
    Univ Innsbruck, Austria.
    Wunderer, Julia
    Univ Innsbruck, Austria.
    Salvenmoser, Willi
    Univ Innsbruck, Austria.
    Ederth, Thomas
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Rothbaecher, Ute
    Univ Innsbruck, Austria.
    Identifying adhesive components in a model tunicate2019Ingår i: Philosophical Transactions of the Royal Society of London. Biological Sciences, ISSN 0962-8436, E-ISSN 1471-2970, Vol. 374, nr 1784, artikel-id 20190197Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Tunicates populate a great variety of marine underwater substrates worldwide and represent a significant concern in marine shipping and aquaculture. Adhesives are secreted from the anterior papillae of their swimming larvae, which attach and metamorphose into permanently adhering, filter-feeding adults. We recently described the cellular composition of the sensory adhesive organ of the model tunicate Ciona intestinalis in great detail. Notably, the adhesive secretions of collocytes accumulate at the tip of the organ and contain glycoproteins. Here, we further explore the components of adhesive secretions and have screened for additional specificities that may influence adhesion or cohesion of the Ciona glue, including other carbohydrate moieties, catechols and substrate properties. We found a distinct set of sugar residues in the glue recognized by specific lectins with little overlap to other known marine adhesives. Surprisingly, we also detect catechol residues that likely originate from an adjacent cellular reservoir, the test cells. Furthermore, we provide information on substrate preferences where hydrophobicity outperforms charge in the attachment. Finally, we can influence the settlement process by the addition of hydrophilic heparin. The further analysis of tunicate adhesive strategies should provide a valuable knowledge source in designing physiological adhesives or green antifoulants. This article is part of the theme issue Transdisciplinary approaches to the study of adhesion and adhesives in biological systems.

  • 1720.
    Zhang, Wenjun
    et al.
    Chinese Academic Science, Peoples R China .
    Wu, Yulei
    Chinese Academic Science, Peoples R China .
    Bao, Qinye
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi. Linköpings universitet, Tekniska högskolan.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Fang, Junfeng
    Chinese Academic Science, Peoples R China .
    Morphological Control for Highly Efficient Inverted Polymer Solar Cells Via the Backbone Design of Cathode Interlayer Materials2014Ingår i: ADVANCED ENERGY MATERIALS, ISSN 1614-6832, Vol. 4, nr 12, s. 1400359-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Two alcohol-soluble organic molecules are synthesized and introduced into inverted organic solar cells as the cathode interlayer. A power conversion efficiency as high as 9.22% is obtained by using the more hydrophobic molecule FTBTF-N as the cathode interlayer. Morphological studies suggest that design of the backbone can help to enhance short-circuit current density and fill factor.

  • 1721.
    Zhang, Xiaonan
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för läkemedelsforskning. Linköpings universitet, Medicinska fakulteten. Department of Oncology-Pathology, Karolinska Institute, Stockholm, Sweden.
    De Milito, Angelo
    Department of Oncology-Pathology, Karolinska Institute, SE-171 76 Stockholm, Sweden.
    Demiroglu-Zergeroglu, Asuman
    Department of Molecular Biology and Genetics, Gebze Technical University, 41400, Gebze, Kocaeli, Turkey.
    Gullbo, Joachim
    Department of Immunology, Genetics and Pathology, Section of Oncology, Uppsala University, Uppsala, Sweden.
    D’Arcy, Padraig
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för läkemedelsforskning. Linköpings universitet, Medicinska fakulteten.
    Linder, Stig
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för läkemedelsforskning. Linköpings universitet, Medicinska fakulteten. Department of Oncology-Pathology, Karolinska Institute, Stockholm, Sweden.
    Eradicating Quiescent Tumor Cells by Targeting Mitochondrial Bioenergetics2016Ingår i: Trends in Cancer, ISSN 2405-8033, Vol. 2, nr 11, s. 7s. 657-663Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Solid tumors contain slowly proliferating cells that show limited sensitivity to conventional cell cycle-active chemotherapeutic drugs. Tumor cells that are not exposed to therapeutically relevant drug concentrations and/or are insensitive to drugs survive treatment and repopulate tumors between treatment cycles. Cancer cells residing in hypoxic and nutritionally compromised environments are expected to have limited metabolic plasticity and to be susceptible to the manipulation of energy supply pathways. Drug screening campaigns using glucose-depleted tumor cells and 3D tumor cell cultures have resulted in the identification of inhibitors of mitochondrial energy production.

  • 1722.
    Zhang, Xiaonan
    et al.
    Karolinska Institute, Sweden.
    Mofers, Arjan
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för läkemedelsforskning. Linköpings universitet, Medicinska fakulteten.
    Hydbring, Per
    Karolinska Institute, Sweden.
    Hagg Olofsson, Maria
    Karolinska Institute, Sweden.
    Guo, Jing
    Karolinska Institute, Sweden; Duke NUS National University of Singapore Medical Sch, Singapore.
    Linder, Stig
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för läkemedelsforskning. Linköpings universitet, Medicinska fakulteten. Karolinska Institute, Sweden.
    D´arcy, Padraig
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för läkemedelsforskning. Linköpings universitet, Medicinska fakulteten.
    MYC is downregulated by a mitochondrial checkpoint mechanism2017Ingår i: OncoTarget, ISSN 1949-2553, E-ISSN 1949-2553, Vol. 8, nr 52, s. 90225-90237Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The MYC proto-oncogene serves as a rheostat coupling mitogenic signaling with the activation of genes regulating growth, metabolism and mitochondrial biogenesis. Here we describe a novel link between mitochondria and MYC levels. Perturbation of mitochondrial function using a number of conventional and novel inhibitors resulted in the decreased expression of MYC mRNA. This decrease in MYC mRNA occurred concomitantly with an increase in the levels of tumor-suppressive miRNAs such as members of the let-7 family and miR-34a-5p. Knockdown of let-7 family or miR-34a-5p could partially restore MYC levels following mitochondria damage. We also identified let-7-dependent downregulation of the MYC mRNA chaperone, CRD-BP (coding region determinant-binding protein) as an additional control following mitochondria damage. Our data demonstrates the existence of a homeostasis mechanism whereby mitochondrial function controls MYC expression.

  • 1723.
    Zhang, Xiaonan
    et al.
    Karolinska Inst, Sweden.
    Selvaraj, Karthik
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för läkemedelsforskning. Linköpings universitet, Medicinska fakulteten.
    Saei, Amir Ata
    Karolinska Inst, Sweden.
    D´arcy, Padraig
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för läkemedelsforskning. Linköpings universitet, Medicinska fakulteten.
    Zubarev, Roman A.
    Karolinska Inst, Sweden.
    Arner, Elias S. J.
    Karolinska Inst, Sweden.
    Linder, Stig
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för läkemedelsforskning. Linköpings universitet, Medicinska fakulteten. Karolinska Inst, Sweden.
    Repurposing of auranofin: Thioredoxin reductase remains a primary target of the drug2019Ingår i: Biochimie, ISSN 0300-9084, E-ISSN 1638-6183, Vol. 162, s. 46-54Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Auranofin is a gold (1)-containing compound used for the treatment of rheumatic arthritis. Auranofin has anticancer activity in animal models and is approved for clinical trials for lung and ovarian carcinomas. Both the cytosolic and mitochondrial forms of the selenoprotein thioredoxin reductase (TrxR) are well documented targets of auranofin. Auranofin was recently reported to also inhibit proteasome activity at the level of the proteasome-associated deubiquitinases (DUBs) UCHL5 and USP14. We here set out to re-examine the molecular mechanism underlying auranofin cytotoxicity towards cultured cancer cells. The effects of auranofin on the proteasome were examined in cells and in vitro, effects on DUB activity were assessed using different substrates. The cellular response to auranofin was compared to that of the 20S proteasome inhibitor bortezomib and the 19S DUB inhibitor b-AP15 using proteomics. Auranofin was found to inhibit mitochondrial activity and to an induce oxidative stress response at IC50 doses. At 2-3-fold higher doses, auranofin inhibits proteasome processing in cells. At such supra-pharmacological concentrations USP14 activity was inhibited. Analysis of protein expression profiles in drug-exposed tumor cells showed that auranofin induces a response distinct from that of the 20S proteasome inhibitor bortezomib and the DUB inhibitor b-AP15, both of which induced similar responses. Our results support the notion that the primary mechanism of action of auranofin is TrxR inhibition and suggest that proteasome DUB inhibition is an off-target effect. Whether proteasome inhibition will contribute to the antineoplastic effect of auranofin in treated patients is unclear but remains a possibility. (C) 2019 Elsevier B.V. and Societe Francaise de Biochimie et Biologie Moleculaire (SFBBM). All rights reserved.

    Publikationen är tillgänglig i fulltext från 2020-04-01 09:23
  • 1724.
    Zhao, Jin J.
    et al.
    Uppsala University, Sweden.
    Halvardson, Jonatan
    Uppsala University, Sweden.
    Zander, Cecilia S.
    Uppsala University, Sweden.
    Zaghlool, Ammar
    Uppsala University, Sweden.
    Georgii-Hemming, Patrik
    Uppsala University, Sweden; Karolinska Institute, Sweden.
    Mansson, Else
    Örebro University Hospital, Sweden.
    Brandberg, Göran
    Pediat Clin, Falun, Sweden.
    Savmarker, Helena E.
    Gävle Central Hospital, Sweden.
    Frykholm, Carina
    Uppsala University, Sweden.
    Kuchinskaya, Ekaterina
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för cellbiologi. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Diagnostikcentrum, Klinisk genetik.
    Thuresson, Ann-Charlotte
    Uppsala University, Sweden.
    Feuk, Lars
    Uppsala University, Sweden.
    Exome sequencing reveals NAA15 and PUF60 as candidate genes associated with intellectual disability2018Ingår i: American Journal of Medical Genetics Part B: Neuropsychiatric Genetics, ISSN 1552-4841, E-ISSN 1552-485X, Vol. 177, nr 1, s. 10-20Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Intellectual Disability (ID) is a clinically heterogeneous condition that affects 2-3% of population worldwide. In recent years, exome sequencing has been a successful strategy for studies of genetic causes of ID, providing a growing list of both candidate and validated ID genes. In this study, exome sequencing was performed on 28 ID patients in 27 patient-parent trios with the aim to identify de novo variants (DNVs) in known and novel ID associated genes. We report the identification of 25 DNVs out of which five were classified as pathogenic or likely pathogenic. Among these, a two base pair deletion was identified in the PUF60 gene, which is one of three genes in the critical region of the 8q24.3 microdeletion syndrome (Verheij syndrome). Our result adds to the growing evidence that PUF60 is responsible for the majority of the symptoms reported for carriers of a microdeletion across this region. We also report variants in several genes previously not associated with ID, including a de novo missense variant in NAA15. We highlight NAA15 as a novel candidate ID gene based on the vital role of NAA15 in the generation and differentiation of neurons in neonatal brain, the fact that the gene is highly intolerant to loss of function and coding variation, and previously reported DNVs in neurodevelopmental disorders.

  • 1725.
    Zhen, Hongyu
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan. State Key Laboratory of Modern Optical Instrumentation, Zhejiang University, Hangzhou 310027, China.
    Hou, Qiong
    S China Normal University, Peoples R China S China University of Technology, Peoples R China .
    Li, Kan
    Zhejiang University, Peoples R China .
    Ma, Zaifei
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Fabiano, Simone
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Zhang, Fengling
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Solution-processed bulk-heterojunction organic solar cells employing Ir complexes as electron donors2014Ingår i: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 2, nr 31, s. 12390-12396Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    To explore enhancing photocurrent in organic solar cells (OSCs) via harvesting triplet excitons, two novel bicycloiridium complexes (R-1 and R-2) are designed and synthesized. Conventional bulk-heterojunction triplet OSCs are solution processed using R-1 or R-2 as sole electron donors and phenyl-C-71-butyric acid methyl ester (PC71BM) as the electron acceptor. A decent short circuit current (J(sc)) of 6.5 mA cm(-2) is achieved though the overlap between the absorption spectrum (with similar to 550 nm absorption onset) of R-2 and the solar flux is relatively small. With an open circuit voltage of 0.74 V and a fill factor of 0.42, an encouraging power conversion efficiency of 2.0% is achieved in the OSCs based on R-2 and PC71BM without any processing additives and post-treatments. Our preliminary result demonstrates the possibility of utilizing Ir complexes as sole electron donors in OSCs, which extends available soluble small molecules for OSCs.

  • 1726.
    Zhybak, Mikael T
    et al.
    Institute of Molecular Biology and Genetics, NAS of Ukraine, Ukraine.
    Fayura, L.Y.
    Institute of Cell Biology, NAS of Ukraine, Ukraine.
    Boretsky, Yu R
    Institute of Cell Biology, NAS of Ukraine, Ukraine.
    Dempsey, Eithne
    Centre for Research in Electroanalytical Technologies, Ireland.
    Gonchar, M.V.
    Institute of Cell Biology, NAS of Ukraine, Ukraine.
    Sibirny, A.A.
    Institute of Cell Biology, NAS of Ukraine, Ukraine.
    Turner, Anthony
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biosensorer och bioelektronik. Linköpings universitet, Tekniska fakulteten.
    Korpan, Yaroslav
    Institute of Molecular Biology and Genetics, NAS of Ukraine, Ukraine.
    Novel L-arginine amperometric assay based on recombinant arginine deiminase and Nafion/PANi composite2016Ingår i: Biosensors 2016 – The World Congress on Biosensors, Elsevier, 2016Konferensbidrag (Övrigt vetenskapligt)
  • 1727.
    Zidar, Josefina
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    The relationship between personality and cognition in the fowl, Gallus gallus2017Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    To cope with a changing environment, animals have traditionally been considered to behave adaptively to each situation faced. Yet, individual behavioural responses can both differ widely within populations, and show between-individual consistency (i.e. describing variation in animal personality). In this thesis, I focus on individual differences in animal personality and cognition (i.e. how animals perceive, process, store and act on environmental stimuli), and explore the possibility that they are interlinked. I use domestic- and red junglefowl (Gallus gallus ssp.), a species that is cognitively, behaviourally and socially complex, to explore these aspects of behaviour, through a series of studies.

    Animal personality and coping styles are frequently used terms to describe within- and between-individual differences in behaviour, which are consistent over time and across various situations. The terms are often used as synonyms, even though they differ in some respects. In paper I, I show that animal personality and coping styles can be measured in red junglefowl, and that behavioural flexibility might be an important aspect for both. Further, I show that the terms should not be used as synonyms since they describe different aspects of behavioural variation.

    In paper II, I observe large individual variation in both personality traits and learning speed in both chicks and adult red junglefowl. Interestingly, learning performance does not correlate across tasks, contrasting what has been found in humans and rodents. Thus, individuals that learn rapidly in one task are not necessarily fast learners in another task. I observe a relationship between personality and cognition that is task- and age-dependent, in which exploration relates to learning speed, but in opposite directions for chicks compared to adult females. In paper III, I show that red junglefowl chicks that are more behaviourally flexible have a stronger preference for new generalised stimuli, than less behaviourally flexible chicks. Behavioural flexibility was associated with fearfulness, indicating variation in reactive-proactive coping styles. In paper IV, I show that early cognitive stimulation to some extent can affect adult personality, thus showing a causal relationship between personality and cognition. Not all personality traits were affected, which might depend on the type of cognitive stimulation chicks were exposed to.

    Important cognitive processes like perception and decision-making, can contain biases. One such bias is called judgment bias, which describes how individuals interpret ambiguous stimuli on a scale from positive to negative (optimism to pessimism). In paper V, I show that alteration of emotional state can influence such biases. Here, unpredictable stress influence judgment bias negatively, when individuals are housed in simpler, but not in complex environments, suggesting that there is an effect of additive stress that lead to reduced optimism. Complexity instead seems to buffer against negative effects of stress, since individuals in complex environments remained optimistic after stress exposure. Furthermore, increased dopamine activity was associated with optimism in chicks. In paper VI, I find that aspects of personality associate with how chicks judge ambiguity. Highly active individuals are more likely to approach cues than less active individuals, and when approaching, individuals that are slow to approach ambiguous cues are more vigilant when assayed in personality assays. Vigilant individuals might be more worried and reactive, which suggest that emotional traits can influence responses in a judgment bias task.

    Taken together, I show consistent behavioural differences among individuals describing personality and coping styles, and variation in cognition. I show that these traits are related, and that there is an interplay between them, in which cognition can influence personality, and vice versa. I further show that judgment may be affected by the individual’s current affective state and personality. Thus, I show a complex relationship between personality and cognition that in combination with environmental effects can help explain behavioural variation.

    Delarbeten
    1. A comparison of animal personality and coping styles in the red junglefowl
    Öppna denna publikation i ny flik eller fönster >>A comparison of animal personality and coping styles in the red junglefowl
    Visa övriga...
    2017 (Engelska)Ingår i: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 130, s. 209-220Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    There is an increased focus in biology on consistent behavioural variation. Several terms are used to describe this variation, including animal personality and coping style. Both terms describe between individual consistency in behavioural variation; however, they differ in the behavioural assays typically used, the expected distribution of response variables, and whether they incorporate variation in behavioural flexibility. Despite these differences, the terms are often used interchangeably. We conducted experiments using juvenile and adult red junglefowl, Gallus gallus, as subjects to explore the degree to which animal personality and coping styles overlap. We demonstrate that animal personality and coping styles can be described in this species, and that shyer individuals had more flexible responses, as expected for coping styles. Behavioural responses from both personality and coping style assays had continuous distributions, and were not clearly separated into two types. Behavioural traits were not correlated and, hence, there was no evidence of a behavioural syndrome. Further, behavioural responses obtained in personality assays did not correlate with those from coping style tests. Animal personality and coping styles are therefore not synonymous in the red junglefowl. We suggest that the terms animal personality and coping style are not equivalent and should not be used interchangeably. (C) 2017 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

    Ort, förlag, år, upplaga, sidor
    ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD, 2017
    Nyckelord
    boldness e; xploration; Gallus gallus; individual differences; stress coping
    Nationell ämneskategori
    Etologi
    Identifikatorer
    urn:nbn:se:liu:diva-139903 (URN)10.1016/j.anbehav.2017.06.024 (DOI)000406939400022 ()
    Anmärkning

    Funding Agencies|Royal Swedish Academy of Sciences; Swedish Research Council; ERC (Advanced Research Grant Genewell); LiU programme for Future research leaders; Swedish research council Formas

    Tillgänglig från: 2017-08-24 Skapad: 2017-08-24 Senast uppdaterad: 2017-09-13
    2. Early experience affects adult personality in the red junglefowl: a role for cognitive stimulation?
    Öppna denna publikation i ny flik eller fönster >>Early experience affects adult personality in the red junglefowl: a role for cognitive stimulation?
    Visa övriga...
    2017 (Engelska)Ingår i: Behavioural Processes, ISSN 0376-6357, E-ISSN 1872-8308, Vol. 134, s. 78-86Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Despite intense research efforts, biologists are still puzzled by the existence of animal personality. While recent studies support a link between cognition and personality, the directionality of this relationship still needs to be clarified. Early-life experiences can affect adult behaviour, and among these, cognitive stimulation has been suggested theoretically to influence personality. Yet, the influence of early cognitive stimulation has rarely been explored in empirical investigations of animal behaviour and personality. We investigated the effect of early cognitive stimulation on adult personality in the red junglefowl (Gallus gallus). To this end, we assessed adult behaviour across a number of personality assays and compared behaviour of individuals previously exposed to a series of learning tasks as chicks, with that of control individuals lacking this experience. We found that individuals exposed to early stimulation as adults were more vigilant and performed fewer escape attempts in personality assays. Other behaviours describing personality traits in the fowl were not affected. We conclude that our results support the hypothesis that early stimulation can affect aspects of adult behaviour and personality, suggesting a hitherto underappreciated causality link between cognition and personality. Future research should aim to confirm these findings and resolve their underlying dynamics and proximate mechanisms.

    Ort, förlag, år, upplaga, sidor
    Elsevier, 2017
    Nyckelord
    Developmental plasticity, Boldness, Exploration, Gallus gallus, Juvenile learning, Neophobia, Vigilance
    Nationell ämneskategori
    Etologi
    Identifikatorer
    urn:nbn:se:liu:diva-131304 (URN)10.1016/j.beproc.2016.06.003 (DOI)000392893600011 ()27329431 (PubMedID)
    Tillgänglig från: 2016-09-13 Skapad: 2016-09-13 Senast uppdaterad: 2018-03-28Bibliografiskt granskad
  • 1728.
    Zidar, Josefina
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Balogh, Alexandra
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska högskolan.
    Favati, Anna
    Stockholm University, Sweden.
    Jensen, Per
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Leimar, Olof
    Stockholm University, Sweden.
    Lovlie, Hanne
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    A comparison of animal personality and coping styles in the red junglefowl2017Ingår i: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 130, s. 209-220Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    There is an increased focus in biology on consistent behavioural variation. Several terms are used to describe this variation, including animal personality and coping style. Both terms describe between individual consistency in behavioural variation; however, they differ in the behavioural assays typically used, the expected distribution of response variables, and whether they incorporate variation in behavioural flexibility. Despite these differences, the terms are often used interchangeably. We conducted experiments using juvenile and adult red junglefowl, Gallus gallus, as subjects to explore the degree to which animal personality and coping styles overlap. We demonstrate that animal personality and coping styles can be described in this species, and that shyer individuals had more flexible responses, as expected for coping styles. Behavioural responses from both personality and coping style assays had continuous distributions, and were not clearly separated into two types. Behavioural traits were not correlated and, hence, there was no evidence of a behavioural syndrome. Further, behavioural responses obtained in personality assays did not correlate with those from coping style tests. Animal personality and coping styles are therefore not synonymous in the red junglefowl. We suggest that the terms animal personality and coping style are not equivalent and should not be used interchangeably. (C) 2017 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

  • 1729.
    Zidar, Josefina
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Balogh, Alexandra
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten. Stockholm Univ, Sweden.
    Favati, Anna
    Stockholm Univ, Sweden.
    Jensen, Per
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Leimar, Olof
    Stockholm Univ, Sweden.
    Sorato, Enrico
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Lovlie, Hanne
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    The relationship between learning speed and personality is age- and task-dependent in red junglefowl2018Ingår i: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 72, nr 10, artikel-id UNSP 168Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Cognition is fundamental to animals lives and an important source of phenotypic variation. Nevertheless, research on individual variation in animal cognition is still limited. Further, although individual cognitive abilities have been suggested to be linked to personality (i.e., consistent behavioral differences among individuals), few studies have linked performance across multiple cognitive tasks to personality traits. Thus, the interplays between cognition and personality are still unclear. We therefore investigated the relationships between an important aspect of cognition, learning, and personality, by exposing young and adult red junglefowl (Gallus gallus) to multiple learning tasks (discriminative, reversal, and spatial learning) and personality assays (novel arena, novel object, and tonic immobility). Learning speed was not correlated across learning tasks, and learning speed in discrimination and spatial learning tasks did not co-vary with personality. However, learning speed in reversal tasks was associated with individual variation in exploration, and in an age-dependent manner. More explorative chicks learned the reversal task faster than less explorative ones, while the opposite association was found for adult females (learning speed could not be assayed in adult males). In the same reversal tasks, we also observed a sex difference in learning speed of chicks, with females learning faster than males. Our results suggest that the relationship between cognition and personality is complex, as shown by its task- and age-dependence, and encourage further investigation of the causality and dynamics of this relationship.Significance statementIn the ancestor of todays chickens, the red junglefowl, we explored how personality and cognition relate by exposing both chicks and adults to several learning tasks and personality assays. Our birds differed in personality and learning speed, while fast learners in one task did not necessarily learn fast in another (i.e., there were no overall smarter birds). Exploration correlated with learning speed in the more complex task of reversal learning: faster exploring chicks, but slower exploring adult females, learned faster, compared to less explorative birds. Other aspects of cognition and personality did not correlate. Our results suggest that cognition and personality are related, and that the relationship can differ depending on task and age of the animal.

  • 1730.
    Zidar, Josefina
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Balogh, Alexandra
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten. Stockholm Univ, Sweden.
    Leimar, Olof
    Stockholm Univ, Sweden.
    Lovlie, Hanne
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Generalization of learned preferences covaries with behavioral flexibility in red junglefowl chicks2019Ingår i: Behavioral Ecology, ISSN 1045-2249, E-ISSN 1465-7279, Vol. 30, nr 5, s. 1375-1381Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The relationship between animal cognition and consistent among-individual behavioral differences (i.e., behavioral types, animal personality, or coping styles), has recently received increased research attention. Focus has mainly been on linking different behavioral types to performance in learning tasks. It has been suggested that behavioral differences could influence also how individuals use previously learnt information to generalize about new stimuli with similar properties. Nonetheless, this has rarely been empirically tested. Here, we therefore explore the possibility that individual variation in generalization is related to variation in behavioral types in red junglefowl chicks (Gallus gallus). We show that more behaviorally flexible chicks have a stronger preference for a novel stimulus that is intermediate between 2 learnt positive stimuli compared to more inflexible chicks. Thus, more flexible and inflexible chicks differ in how they generalize. Further, behavioral flexibility correlates with fearfulness, suggesting a coping style, supporting that variation in generalization is related to variation in behavioral types. How individuals generalize affects decision making and responses to novel situations or objects, and can thus have a broad influence on the life of an individual. Our results add to the growing body of evidence linking cognition to consistent behavioral differences.

  • 1731.
    Zidar, Josefina
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Campderrich, Irene
    Department of Animal Environment and Health, Swedish University of Agricultural Sciences, Uppsala, Sweden; Neiker-Tecnalia, Department of Animal Production, Vitoria-Gasteiz, Spain.
    Jansson, Emilie
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Wichman, Anette
    Department of Animal Environment and Health, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Winberg, Svante
    Department of Neuroscience, Uppsala Biomedical Centre BMC, Uppsala University, Uppsala, Sweden.
    Keeling, Linda
    Department of Animal Environment and Health, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Løvlie, Hanne
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Environmental complexity buffers against stress-induced negative judgement bias in female chickens2018Ingår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 8, nr 5404Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Cognitive processes are often biased by emotions. In humans, affective disorders are accompanied by pessimistic judgement, while optimistic judgement is linked to emotional stability. Similar to humans, animals tend to interpret ambiguous stimuli negatively after experiencing stressful events, although the long-lasting impact on judgement bias has rarely been investigated. We measure judgement bias in female chicks (Gallus gallus domesticus) after exposure to cold stress, and before and after exposure to additional unpredictable stressors. Additionally, we explore if brain monoamines can explain differences in judgement bias. Chicks exposed to cold stress did not differ in judgement bias compared to controls, but showed sensitivity to additional stressors by having higher motivation for social reinstatement. Environmental complexity reduced stress-induced negative judgement bias, by maintaining an optimistic bias in individuals housed in complex conditions even after stress exposure. Moreover, judgement bias was related to dopamine turnover rate in mesencephalon, with higher activity in individuals that had a more optimistic response. These results demonstrate that environmental complexity can buffer against negative effects of additive stress and that dopamine relates to judgement bias in chicks. These results reveal that both internal and external factors can mediate emotionally biased judgement in animals, thus showing similarities to findings in humans.

  • 1732.
    Zidar, Josefina
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Sorato, Enrico
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Malmqvist, Ann-Marie
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Jansson, Emelie
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Rosher, Charlotte
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten. Faculty of Life Sciences, University of Manchester, Manchester, UK.
    Jensen, Per
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Favati, Anna
    Department of Zoology, Stockholm University, Stockholm, Sweden.
    Løvlie, Hanne
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Early experience affects adult personality in the red junglefowl: a role for cognitive stimulation?2017Ingår i: Behavioural Processes, ISSN 0376-6357, E-ISSN 1872-8308, Vol. 134, s. 78-86Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Despite intense research efforts, biologists are still puzzled by the existence of animal personality. While recent studies support a link between cognition and personality, the directionality of this relationship still needs to be clarified. Early-life experiences can affect adult behaviour, and among these, cognitive stimulation has been suggested theoretically to influence personality. Yet, the influence of early cognitive stimulation has rarely been explored in empirical investigations of animal behaviour and personality. We investigated the effect of early cognitive stimulation on adult personality in the red junglefowl (Gallus gallus). To this end, we assessed adult behaviour across a number of personality assays and compared behaviour of individuals previously exposed to a series of learning tasks as chicks, with that of control individuals lacking this experience. We found that individuals exposed to early stimulation as adults were more vigilant and performed fewer escape attempts in personality assays. Other behaviours describing personality traits in the fowl were not affected. We conclude that our results support the hypothesis that early stimulation can affect aspects of adult behaviour and personality, suggesting a hitherto underappreciated causality link between cognition and personality. Future research should aim to confirm these findings and resolve their underlying dynamics and proximate mechanisms.

  • 1733.
    Ziels, Ryan
    et al.
    Linköpings universitet, Biogas Research Center. Civil and Environmental Engineering, University of Washington, WA, USA.
    Karlsson, Anna
    Linköpings universitet, Biogas Research Center. Scandinavian Biogas Fuels AB, Sweden.
    Beck, David A.C.
    Science Institute, University of Washington, WA, USA.
    Ejlertsson, Jörgen
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Biogas Research Center. Linköpings universitet, Filosofiska fakulteten. Scandinavian Biogas Fuels AB, Sweden.
    Shakeri Yekta, Sepehr
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Biogas Research Center. Linköpings universitet, Filosofiska fakulteten.
    Björn, Annika
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Biogas Research Center. Linköpings universitet, Filosofiska fakulteten.
    Stensel, H. David
    Civil and Environmental Engineering, University of Washington, WA, USA.
    Svensson, Bo H.
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Biogas Research Center. Linköpings universitet, Filosofiska fakulteten.
    Microbial community adaptation influences long-chain fatty acidconversion during anaerobic codigestion of fats, oils, and grease withmunicipal sludge2016Ingår i: Water Research, ISSN 0043-1354, E-ISSN 1879-2448, Vol. 103, s. 372-382Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Codigesting fats, oils, and greases with municipal wastewater sludge can greatly improve biomethanerecovery at wastewater treatment facilities. Process loading rates of fats, oils, and greases have beenpreviously tested with little knowledge of the digester microbial community structure, and high transientfat loadings have led to long chain fatty acid (LCFA) accumulation and digester upsets. This studyutilized recently-developed quantitative PCR assays for syntrophic LCFA-degrading bacteria along with16S amplicon sequencing to relate changes in microbial community structure to LCFA accumulationduring transient loading increases to an anaerobic codigester receiving waste restaurant oil andmunicipal wastewater sludge. The 16S rRNA gene concentration of the syntrophic b-oxidizing genusSyntrophomonas increased to ~15% of the Bacteria community in the codigester, but stayed below 3% inthe control digester that was fed only wastewater sludge. Methanosaeta and Methanospirillum were thedominant methanogenic genera enriched in the codigester, and together comprised over 80% of theArchaea community by the end of the experimental period. Constrained ordination showed that changesin the codigester Bacteria and Archaea community structures were related to measures of digester performance.Notably, the effluent LCFA concentration in the codigester was positively correlated to thespecific loading rate of waste oil normalized to the Syntrophomonas 16S rRNA concentration. Specificloading rates of 0e1.5 1012 g VS oil/16S gene copies-day resulted in LCFA concentrations below 30 mg/g TS, whereas LCFA accumulated up to 104 mg/g TS at higher transient loading rates. Based on thecommunity-dependent loading limitations found, enhanced biomethane production from high loadingsof fats, oils and greases can be achieved by promoting a higher biomass of slow-growing syntrophicconsortia, such as with longer digester solids retention times. This work also demonstrates the potentialfor controlling the loading rate of fats, oils, and greases based on the analysis of the codigester communitystructure, such as with quantitative PCR measurements of syntrophic LCFA-degrading bacteriaabundance.

  • 1734.
    Ziels, Ryan M.
    et al.
    University of Washington, WA 98195 USA.
    Beck, David A. C.
    University of Washington, WA 98195 USA; University of Washington, WA 98195 USA.
    Genero, Magalí Martí
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Gough, Heidi L.
    University of Washington, WA 98195 USA.
    Stensel, H. David
    University of Washington, WA 98195 USA.
    Svensson, Bo
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Monitoring the dynamics of syntrophic beta-oxidizing bacteria during anaerobic degradation of oleic acid by quantitative PCR2015Ingår i: FEMS Microbiology Ecology, ISSN 0168-6496, E-ISSN 1574-6941, Vol. 91, nr 4Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The ecophysiology of long-chain fatty acid-degrading syntrophic beta-oxidizing bacteria has been poorly understood due to a lack of quantitative abundance data. Here, TaqMan quantitative PCR (qPCR) assays targeting the 16S rRNA gene of the known mesophilic syntrophic beta-oxidizing bacterial genera Syntrophomonas and Syntrophus were developed and validated. Microbial community dynamics were followed using qPCR and Illumina-based high-throughput amplicon sequencing in triplicate methanogenic bioreactors subjected to five consecutive batch feedings of oleic acid. With repeated oleic acid feeding, the initial specific methane production rate significantly increased along with the relative abundances of Syntrophomonas and methanogenic archaea in the bioreactor communities. The novel qPCR assays showed that Syntrophomonas increased from 7 to 31% of the bacterial community 16S rRNA gene concentration, whereas that of Syntrophus decreased from 0.02 to less than 0.005%. High-throughput amplicon sequencing also revealed that Syntrophomonas became the dominant genus within the bioreactor microbiomes. These results suggest that increased specific mineralization rates of oleic acid were attributed to quantitative shifts within the microbial communities toward higher abundances of syntrophic beta-oxidizing bacteria and methanogenic archaea. The novel qPCR assays targeting syntrophic beta-oxidizing bacteria may thus serve as monitoring tools to indicate the fatty acid beta-oxidization potential of anaerobic digester communities.

  • 1735.
    Ziels, Ryan M.
    et al.
    Department of Civil Engineering, The University of British Columbia, Vancouver, BC, Canada.
    Svensson, Bo H
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten. Linköpings universitet, Biogas Research Center.
    Sundberg, Carina
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell miljöteknik. Linköpings universitet, Filosofiska fakulteten.
    Larsson, Madeleine
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten. Linköpings universitet, Biogas Research Center.
    Karlsson, Anna
    Scandinavian Biogas Fuels AB, Stockholm, Sweden.
    Shakeri Yekta, Sepehr
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten. Linköpings universitet, Biogas Research Center.
    Microbial rRNA gene expression and co-occurrence profiles associate with biokinetics and elemental composition in full-scale anaerobic digesters2018Ingår i: Microbial Biotechnology, ISSN 1751-7907, E-ISSN 1751-7915, Vol. 11, nr 4, s. 694-709Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study examined whether the abundance and expression of microbial 16S rRNA genes were associated with elemental concentrations and substrate conversion biokinetics in 20 full-scale anaerobic digesters, including seven municipal sewage sludge (SS) digesters and 13 industrial codigesters. SS digester contents had higher methane production rates from acetate, propionate and phenyl acetate compared to industrial codigesters. SS digesters and industrial codigesters were distinctly clustered based on their elemental concentrations, with higher concentrations of NH3-N, Cl, K and Na observed in codigesters. Amplicon sequencing of 16S rRNA genes and reverse-transcribed 16S rRNA revealed divergent grouping of microbial communities between mesophilic SS digesters, mesophilic codigesters and thermophilic digesters. Higher intradigester distances between Archaea 16S rRNA and rRNA gene profiles were observed in mesophilic codigesters, which also had the lowest acetate utilization biokinetics. Constrained ordination showed that microbial rRNA and rRNA gene profiles were significantly associated with maximum methane production rates from acetate, propionate, oleate and phenyl acetate, as well as concentrations of NH3-N, Fe, S, Mo and Ni. A co-occurrence network of rRNA gene expression confirmed the three main clusters of anaerobic digester communities based on active populations. Syntrophic and methanogenic taxa were highly represented within the subnetworks, indicating that obligate energy-sharing partnerships play critical roles in stabilizing the digester microbiome. Overall, these results provide new evidence showing that different feed substrates associate with different micronutrient compositions in anaerobic digesters, which in turn may influence microbial abundance, activity and function.

  • 1736.
    Zook, Alexander E
    et al.
    Department of Ecology and Evolution, University of Chicago, United States.
    Eklöf, Anna
    Department of Ecology and Evolution, University of Chicago, United States.
    Jacob, Ute
    Institute for Hydrobiologie and Fisheries Science, University Hamburg, Germany.
    Allesina, Stefano
    Department of Ecology and Evolution, University of Chicago, United States; Computation Institute, University of Chicago, United States.
    Food webs: ordering species according to body size yields high degree of intervality2011Ingår i: Journal of Theoretical Biology, ISSN 0022-5193, E-ISSN 1095-8541, Vol. 271, nr 1, s. 106-113Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Food webs, the networks describing "who eats whom" in an ecosystem, are nearly interval, i.e. there is a way to order the species so that almost all the resources of each consumer are adjacent in the ordering. This feature has important consequences, as it means that the structure of food webs can be described using a single (or few) species' traits. Moreover, exploiting the quasi-intervality found in empirical webs can help build better models for food web structure. Here we investigate which species trait is a good proxy for ordering the species to produce quasi-interval orderings. We find that body size produces a significant degree of intervality in almost all food webs analyzed, although it does not match the maximum intervality for the networks. There is also a great variability between webs. Other orderings based on trophic levels produce a lower level of intervality. Finally, we extend the concept of intervality from predator-centered (in which resources are in intervals) to prey-centered (in which consumers are in intervals). In this case as well we find that body size yields a significant, but not maximal, level of intervality. These results show that body size is an important, although not perfect, trait that shapes species interactions in food webs. This has important implications for the formulation of simple models used to construct realistic representations of food webs.

  • 1737.
    Zou, Huiyun
    et al.
    Shandong Univ, Peoples R China.
    Zheng, Beiwen
    Zhejiang Univ, Peoples R China.
    Sun, Mingli
    Ctr Dis Prevent and Control, Peoples R China.
    Ottoson, Jakob
    Natl Food Agcy, Sweden.
    Li, Yubo
    Ctr Dis Prevent and Control, Peoples R China.
    Berglund, Björn
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi, infektion och inflammation. Linköpings universitet, Medicinska fakulteten. Zhejiang Univ, Peoples R China.
    Chi, Xiaohui
    Shandong Univ, Peoples R China.
    Ji, Xiang
    Shandong Univ, Peoples R China.
    Li, Xuewen
    Shandong Univ, Peoples R China.
    Lundborg, Cecilia Stalsby
    Karolinska Inst, Sweden.
    Nilsson, Lennart
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi, infektion och inflammation. Linköpings universitet, Medicinska fakulteten.
    Evaluating Dissemination Mechanisms of Antibiotic-Resistant Bacteria in Rural Environments in China by Using CTX-M-Producing Escherichia coli as an Indicator2019Ingår i: Microbial Drug Resistance, ISSN 1076-6294, E-ISSN 1931-8448Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    It is becoming increasingly recognized that the environment plays an important role both in the emergence and in dissemination of antibiotic-resistant bacteria (ARB), Mechanisms and factors facilitating this development are, however, not yet well understood. The high detection rate of CTX-M genes in environmental sources provides an opportunity to explore this issue. In this study, 88 CTX-M-producing Escherichia coli were isolated from 30 pig feces samples from 30 pig farms and 201 environmental samples. CTX-M-producing E. coli was detected with the following frequencies in the different types of samples: pig feces, 73%; river water, 64%; river sediment, 52%; wastewater, 31%; drinking water, 23%; outlet sediment, 21%; soil, 17%; and vegetables, 4.4%. Dissemination of CTX-M-producing E. coli to different environmental matrices was evaluated by analyzing the genetic relatedness of isolates from different environmental sources, and putative transmission routes through bird feces, pig feces, drinking water, river sediment, river water, and wastewater were hypothesized. Dissemination through these routes is likely facilitated by anthropogenic activities and environmental factors. Wild birds as potential vectors for dissemination of CTX-M-producing E. coli have the capacity to spread ARB across long distances. Regional dissemination between different environmental matrices of CTX-M-producing E. coli increases the exposure risk of humans and animals in the area.

    Publikationen är tillgänglig i fulltext från 2020-05-22 08:00
  • 1738.
    Zupan, Manja
    et al.
    Swedish University of Agricultural Sciences, Department of Animal Environment and Health, Box 7068, Uppsala, SE-750 07, Uppsala, Sweden.
    Buskas, Julia
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Altimiras, Jordi
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Keeling, Linda J.
    Swedish University of Agricultural Sciences, Department of Animal Environment and Health, Box 7068, Uppsala, SE-750 07, Uppsala, Sweden.
    Assessing positive emotional states in dogs using heart rate and heartrate variability2016Ingår i: Physiology and Behavior, ISSN 0031-9384, E-ISSN 1873-507X, Vol. 155, s. 102-111Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Since most animal species have been recognized as sentient beings, emotional state may be a good indicator ofwelfare in animals. The goal of this study was to manipulate the environment of nine beagle research dogs tohighlight physiological responses indicative of different emotional experiences. Stimuli were selected to be amore or a less positive food (meatball or food pellet) or social reward (familiar person or less familiar person).That all the stimuli were positive and of different reward value was confirmed in a runway motivation test.Dogs were tested individually while standing facing a display theatre where the different stimuli could beshown by lifting a shutter. The dogs approached and remained voluntarily in the test system. They were testedin four sessions (of 20 s each) for each of the four stimuli. A test session consisted of four presentation phases(1st exposure to stimulus, post exposure, 2nd exposure, and access to reward). Heart rate (HR) and heart ratevariability (HRV) responses were recorded during testing in the experimental room and also when lying restingin a quiet familiar room. A newmethod of ‘stitching’ short periods of HRV data together was used in the analysis.When testing different stimuli, no significant differenceswere observed in HR and LF:HF ratio (relative power inlow frequency (LF) and the high-frequency (HF) range), implying that the sympathetic tone was activated similarlyfor all the stimuli and may suggest that dogs were in a state of positive arousal. A decrease of HF was associatedwith the meatball stimulus compared to the food pellet and the reward phase (interacting with the personor eating the food) was associated with a decrease in HF and RMSSD (root mean square of successive differencesof inter-beat intervals) compared to the preceding phase (looking at the person or food). This suggests that parasympatheticdeactivation is associated with a more positive emotional state in the dog. A similar reduction in HFandRMSSDwas found in the test situation compared to the resting situation. This is congruentwith the expectedautonomic effects related to postural shift i.e. sympathetic activation and parasympathetic withdrawal, duringstanding versus lying, but it cannot explain the parasympathetic deactivation in response to the more positivestimuli since the dogs were always standing in the test situation.Wediscuss the systematic pattern of responses,which support that increased HRand LF:HF ratio are associatedwithemotional arousal, but add the newproposalthat a combined decrease inRMSSD and HFmay reflect a more positively valencedemotional state evenwhen anindividual is already in a positive psychological state.

  • 1739.
    Zuse, Ann
    et al.
    Institute of Medicinal and Pharmaceutical Chemistry, Westphalian Wilhelms-University, Hittorfstrasse 58-62, D-48149 Münster, Germany; Manitoba Institute of Cell Biology, CancerCare Manitoba, Department of Biochemistry and Medical Genetics, Winnipeg, Canada.
    Prinz, Helge
    Institute of Medicinal and Pharmaceutical Chemistry, Westphalian Wilhelms-University, Hittorfstrasse 58-62, D-48149 Münster, Germany.
    Müller, Klaus
    Institute of Medicinal and Pharmaceutical Chemistry, Westphalian Wilhelms-University, Hittorfstrasse 58-62, D-48149 Münster, Germany.
    Schmidt, Peter
    Zentaris GmbH, Weismüllerstrasse 50, D-60314 Frankfurt, Germany.
    Günther, Eckhard G.
    Zentaris GmbH, Weismüllerstrasse 50, D-60314 Frankfurt, Germany.
    Schweizer, Frank
    Department of Chemistry, Univ. Manitoba, Winnipeg, Canada.
    Prehn, Jochen H.M.
    Department of Physiology and RCSI Research Institute, St. Stephen's Green, Dublin, Ireland.
    Los, Marek Jan
    Manitoba Institute of Cell Biology, Cancer Care Manitoba; Manitoba Institute of Child Health; Department of Biochemistry and Medical Genetics; Department of Human Anatomy and Cell Science, University Manitoba, Winnipeg, Canada, .
    9-benzylidene-naphtho[2,3-b]thiophen-4-ones and benzylidene-9(10H)-anthracenones as novel tubulin interacting agents with high apoptosis-inducing activity2007Ingår i: European Journal of Pharmacology, ISSN 0014-2999, E-ISSN 1879-0712, Vol. 575, nr 1-3, s. 34-45Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Tubulin-binding 9-benzylidene-naphtho[2,3-b]thiophen-4-ones 1a and 1b and benzylidene-9(10H)-anthracenone 2 were evaluated for their ability to induce cell death. We examined the effect of the molecules on cell cycle progression, organization of microtubule networks, and apoptosis induction. As determined by flow cytometry, cancer cells were predominantly arrested in metaphase with 4N DNA before cell death occurred. By using indirect immunofluorescence techniques we visualized microtubule depolymerization recognizable by short microtubule fragments scattered around the nucleus. The incubation with 1a and 2 resulted in chromatin condensation, nuclear fragmentation, and cell shrinkage, which are, among others, typical features of apoptotic cell death. Furthermore, time- and dose-dependent induction of apoptosis in SH-SY5Y cells was detected via cleavage of Ac-DEVD-AMC, a fluorigenic substrate for caspase-3. We observed a lower apoptotic activity in neuroblastoma cells overexpressing Bcl-xL, suggesting activation of the mitochondrial apoptosis pathway. Western blot analysis demonstrated that caspase-3, an apoptosis mediator, was activated in a time-dependent manner after exposure of SH-SY5Y cells to drugs 1a and 2. Taken together, the agents investigated in the present study display strong apoptosis-inducing activity and therefore show promise for the development of novel chemotherapeutics.

  • 1740. Zuse, Anne
    et al.
    Prinz, Helge
    Mueller, Klaus
    Prehn, Jochen
    Los, Marek Jan
    BioApplications Enterprises, Winnipeg, MB, Canada; Manitoba Institute of Cell Biology, Cancer Care Manitoba; Manitoba Institute of Child Health; Department of Biochemistry and Medical Genetics; Department of Human Anatomy and Cell Science, University Manitoba, Winnipeg, Canada, .
    Design of novel small molecule inhibitors of tubulin polymerization with high apoptosis-inclucing activity2007Ingår i: Molecular Cancer Therapeutics, ISSN 1535-7163, E-ISSN 1538-8514, Vol. 6, nr 12, s. 3421S-3421SArtikel i tidskrift (Refereegranskat)
  • 1741.
    Åberg, Elin
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska högskolan.
    Turbiditet som ersättningsmått för totalfosforhalt i kustmynnande vattendrag i Östergötland2014Självständigt arbete på grundnivå (kandidatexamen), 10,5 poäng / 16 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Övergödning av Östersjön är ett stort problem orsakat av ett överskott av kväve och fosfor. I de östra delarna av Östergötland består jordarna till stor del av lera och innehåller rikligt med fosfor bundet till lerpartiklarna. Vid erosion från jordarna grumlas kustmynnande vattendrag och fosfor transporteras ut till Östersjön. Syftet med projektet var att undersöka om mätning av turbiditet kan användas för att uppskatta koncentrationen av totalfosfor i Östergötlands kustmynnande vattendrag. En fältstudie genomfördes där 41 vattendrag provtogs en gång per lokal den 7 - 11 april 2014. Vattenprover från lokalerna analyserades med avseende på totalfosfor, molybdatreaktiv fosfor, turbiditet och färg (absorbans 420 nm). I genomsnitt så bestod 80 % av totalfosfor av partikulärt bunden fosfor. Det fanns ett signifikant samband mellan totalfosfor och turbiditet (R2 adj =0,879, P<0,01, linjär regression) men inte mellan färg och totalfosfor. Vid multipel regression med turbiditet och färg som oberoende variabler förbättras förklaringsgraden så marginellt (R2adj=0,886) att det inte motiverar analys av färg, då det ger en ökad arbetsinsats. Projektet visar att turbiditet går att använda som ersättningsmått för totalfosforhalt i kustmynnande vattendrag i Östergötland.

  • 1742.
    Åkesson, Anna
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Alternativ modell för miljöundervisning i dagens gymnasieskola - modellekosystem2011Självständigt arbete på avancerad nivå (yrkesexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Studier visar att dagens elever känner oro inför framtiden och de klimatförändringar vår värld utsätts för. Skolverkets nationella kartläggning utav miljöundervisning i skolan visar dock att cirka hälften av de tillfrågade gymnasielärarna inte bedriver någon undervisning i ämnet. Denna studie beskriver en alternativ modell för undervisning i klimatfrågor. Elever ges genom modellering av ekosystem möjlighet att fördjupa sin förståelse kring klimatförändringar i samband med exploatering av topp-predatorer. Detta är ett realistiskt problem då en mängd studier visar att dagens ekosystem utsätts för en mängd stressfaktorer, med ursprung i klimatförändringar, och att exploatering av topp-predatorer kan leda till konsekvenser med artutdöende som följd. Modellen som används i undersökningen är en generell Lotka-Volterra-modell vilken fungerar som analytiskt verktyg. Skolverket betonar matematikens roll som ämnesöverskridande verktyg och modellekosystem ger elever möjlighet att använda matematiska kunskaper i ett verkligt scenario. I studien undersöks även hur pass stor exploatering topp-predatorer kan utsättas för i takt med ökade klimatförändringar. De undersökta områdena inbegriper tre- och fyr-artssystem i marina och terrestra miljöer. Resultaten visar att exploateringen måste minska i takt med ökade klimatorsakade förändringar i samtliga fall, undantag terrestra tre-artsystem som utsätts för förändrade interaktionsstyrkor.

  • 1743.
    Åkesson, Julia
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Bioinformatik.
    Robust Community Predictions of Hubs in Gene Regulatory Networks2018Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Many diseases, such as cardiovascular diseases, cancer and diabetes, originate from several malfunctions in biological systems. The human body is regulated by a wide range of biological systems, composed of biological entities interacting in complex networks, responsible for carrying out specific functions. Some parts of the networks, such as hubs serving as master regulators, are more important for maintaining a function. To find the cause of diseases, where hubs are possible disease regulators, it is critical to know the structure of these biological systems. Such structures can be reverse engineered from high-throughput data with measured levels of biological entities. However, the complexity of biological systems makes inferring their structure a complicated task, demanding the use of computational methods, called network inference methods. Today, many network inference methods have been developed, that predicts the interactions of biological networks, with varying degree of success. In the DREAM5 challenge 35 network inference methods were evaluated on how well interactions in gene regulatory networks (GRNs) were predicted. Herein, in contrast to the DREAM5 challenge, we have evaluated network inference methods’ ability to predict hubs in GRNs. In accordance with the DREAM5 challenge, different methods performed the best on different data sets. Moreover, we discovered that network inference methods were not able to identify hubs from groups of similarly expressed genes. Also, we noticed that hubs in GRNs had a distinct expression in the data, leading to the development of a new method (the PCA method) for the prediction of hubs. Furthermore, the DREAM5 challenge showed that community predictions, combining the predictions from many network inference methods, resulted in more robust predictions of interactions. Herein, the community approach was applied on predicting hubs, with the conclusion that community predictions is the more robust approach. However, we also concluded that it was enough to combine 6-7 network inference methods to achieve robust predictions of hubs.

  • 1744.
    Årevall, Jonatan
    Linköpings universitet, Institutionen för fysik, kemi och biologi.
    Klimatinducerade fenologiförändringar och dess effekter i näringsväven2011Självständigt arbete på grundnivå (kandidatexamen), 10,5 poäng / 16 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Klimatet påverkar djurpopulationer genom ett flertal processer. Dessa processer inkluderarreproduktion, fenologi och jaktframgång. Genom att påverka arters fenologi påverkar klimatet ävenhur arter interagerar med varandra. Om en klimatinducerad fenologiförändring stimulerar en basalart att knoppa tidigare på våren kommer det att påverka länkar till andra arter i näringsväven pågrund av en tidsförskjutning till andra trofinivåer. Detta beroende för ett rovdjur att varasynkroniserad med sitt byte kallas för match/mismatch-hypotesen (MMH). Studier har indikerat attarter högre upp i näringsväven anpassar sig långsammare än arter lägre ned i näringsväven medkortare generationstid. En klimatinducerad fenologiförändring i basala arter kan därför förväntaspåverka densiteten och utdöendehastigheten för arter högre upp i näringsväven. Studien använderen avtagande rekryteringsförmåga för att modellera klimatförändringars effekt på trianguläranäringsvävar med tre trofinivåer. För att göra detta har en generell Lotka-Volterra modell används.Från resultaten av den här studien dras också slutsatsen att, i en näringsväv med tre trofinivåer,densiteten av herbivorer och karnivorer avtar som svar på en ökad klimatförändring.Utdöendehastigheten för rovdjur ökar också snabbt som svar på en ökande klimatförändring.

  • 1745.
    Årevall, Jonatan
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Teoretisk Biologi. Linköpings universitet, Tekniska fakulteten.
    Early, Regan
    Univ Exeter Penryn Campus, England.
    Estrada, Alba
    Oviedo Univ Campus Mieres, Spain.
    Wennergren, Uno
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Teoretisk Biologi. Linköpings universitet, Tekniska fakulteten.
    Eklöf, Anna
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Teoretisk Biologi. Linköpings universitet, Tekniska fakulteten.
    Conditions for successful range shifts under climate change: The role of species dispersal and landscape configuration2018Ingår i: Diversity & distributions: A journal of biological invasions and biodiversity, ISSN 1366-9516, E-ISSN 1472-4642, Vol. 24, nr 11, s. 1598-1611Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Aim: Ongoing climate change is currently modifying the geographical location of areas that are climatically suitable for species. Understanding a species ability to successfully shift its geographical range would allow us to assess extinction risks and predict future community compositions. We investigate how habitat configuration impedes or promotes climate-driven range shifts, given different speeds of climate change and dispersal abilities. Location: Theoretical, but illustrated with European examples. Methods: We model how a species ability to track a directional shift in climatic conditions is affected by (a) species dispersal abilities; (b) speed of climatic shift; and (c) spatial arrangement of the habitat. Our modelling framework includes within-and between-patch population dynamics and uses ecologically realistic habitat distributions and dispersal scenarios (verified with data from a set of European mammal species) and, as such, is an improvement of classical range shift models. Result: In landscapes with a homogeneous distribution of suitable habitats, all but the least dispersive species will be able to range shift. However, species with high dispersal ability will have lower population densities after range shift. In heterogeneous landscapes species ability to range shift is far more variable and heavily dependent on the habitat configuration. This means that landscape configuration in combination with the speed of climate change and species dispersal abilities give rise to nonlinear effects on population sizes and survival after a climatic shift. Main conclusions: Our analyses point out the importance of accounting for the interplay of species dispersal and the landscape configuration when estimating future climate impact on species. These results link ecologically important attributes of both species and their landscapes to outcomes of species range shift, and thereby long-term persistence of ecological communities.

  • 1746.
    Åström, Therese
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Betydelsen av skogskontinuitet och egenskaper hos gran för förekomst av Lecanactis abietina2013Självständigt arbete på grundnivå (kandidatexamen), 10,5 poäng / 16 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Skyddandet av gamla skogar med höga naturvärden är en viktig del i bevarandet av den biologiska mångfalden. För att kunna lokalisera och kvalitetsbedöma skogar med höga naturvärden används signalarter. En av dessa signalarter är Lecanactis abietina, gammelgranslav. Syftet med denna studie är att identifiera vilka faktorer som påverkar förekomst av signalarten L. abietina och täckningsgraden av apothecier. Studien utfördes i Ycke, Ullstämma och Säby Västerskog, vilka är naturreservat av olika ålder i Linköpings kommun, Östergötlands län. I de studerade områdena undersöktes samtliga granar med en diameter över 5 cm. Granarnas diameter och skuggning mättes, vid förekomst av L. abietina undersöktes förekomsten av apothecier, lavens täckningsgrad, maxhöjd och i vilka väderstreck laven förekom. Ett mindre urval av granarna borrades och ålderbestämdes. Resultatet visar att faktorerna som påverkar förekomst av L. abietina och täckningsgraden av apothecier främst är, skoglig kontinuitet i området, samt granarnas diameter och ålder. Resultaten från denna studie styrker användandet av L. abietina som lämplig indikatorart i Östergötland då lavens förekomst och spridning tydligt  speglade skogens kontinuitet (störst förekomst i de äldsta reservaten) och trädens egenskaper. Studien visar även att enbart förekomst inte räcker för att påvisa skog med höga naturvärden, utan de viktigaste faktorerna var förekomst av fertil lav, lavens täckningsgrad och frekvens på granar. Studien visar även att bevarandet av skogar med lång kontinuitet och förekomst av stora och gamla träd är viktigt för förekomsten av L. abietina.

  • 1747.
    Öberg, Elisabet
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Kemi. Linköpings universitet, Tekniska fakulteten.
    Appelqvist, Hanna
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Kemi. Linköpings universitet, Tekniska fakulteten.
    Nilsson, Peter
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Kemi. Linköpings universitet, Tekniska fakulteten.
    Non-fused Phospholes as Fluorescent Probes for Imaging of Lipid Droplets in Living Cells2017Ingår i: Frontiers in Chemistry, E-ISSN 2296-2646, Vol. 5, artikel-id 28Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Molecular tools for fluorescent imaging of specific compartments in cells are essential for understanding the function and activity of cells. Here, we report the synthesis of a series of pyridyl- and thienyl-substituted phospholes and the evaluation of these dyes for fluorescent imaging of cells. The thienyl-substituted phospholes proved to be successful for staining of cultured normal and malignant cells due to their fluorescent properties and low toxicity. Co-staining experiments demonstrated that these probes target lipid droplets, which are, lipid-storage organelles found in the cytosol of nearly all cell types. Our findings confirm that thienyl-substituted phospholes can be utilized as fluorescent tools for vital staining of cells, and we foresee that these fluorescent dyes might be used in studies to unravel the roles that lipid droplets play in cellular physiology and in diseases.

  • 1748.
    Ödling, Sara
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska fakulteten.
    Is there a correlation between the nutrient content and variation in the HvNAM-2 gene in Hordeum vulgare?2015Självständigt arbete på grundnivå (kandidatexamen), 10,5 poäng / 16 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Barley is one of the most important cereal crops in the world and a better understanding of the factors that regulates the nutrient content in the grain is of high interest. The industrial breeding during the last century has led to bigger yield but possibly a decrease in nutrient content. In wheat, the NAM-B1 gene is a well-studied gene that affects the grain protein and micronutrient content. Two orthologue genes in barley HvNAM-1 and HvNAM-2 are candidate genes to play a similar role in the barley senescence process.

    I have looked for a correlation between the diversity in the HvNAM-2 gene and nutrient content in 37 Nordic barley accessions. The samples were sequenced and then aligned and analyzed for variation. I found three haplotypes which were compared in nutrient content and in micronutrient content. No significant difference between the haplotypes was found, which can be due to small sample size or that no correlation exists between the grain protein content and the HvNAM-2 gene variation. Significant correlation was however found between the nitrogen content and the micronutrient contents that indicate that the pathways of all the nutrients’ mobilizations are tightly coupled. For future research a bigger number of accessions, preferably at least 100, need to be analyzed to be able to give any conclusions. The molecular mechanisms in the cells during senescence also need further investigation.

  • 1749.
    Östensson, Frida
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi.
    Grain protein content and its assocoation with the NAC-protein genes HvNAM1 and HvNAM2 in Nordic barley2016Självständigt arbete på grundnivå (kandidatexamen), 10,5 poäng / 16 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Hunger is a problem faced by many people all over the world, and as the population grows, so does the need for food such as cereals. Because of this, the need for food with higher protein and nutrient content will be increasingly important. NAM-B1, a NAC-protein gene in wheat, has been shown to control the grain protein content and nutrient values, as well as senescence. In barley, two orthologous genes have been found, HvNAM1 and HvNAM2. This study focuses on Nordic barley accessions and how haplotypes of HvNAM1 and HvNAM2 correlate to the grain protein content (GPC) and nutrient content. No correlations between the different haplotypes of the HvNAM genes and the nutrient content and GPC were found. No differences in nutrient content and GPC were found in Nordic accessions originating from Sweden, Norway, Finland, or Denmark, nor were differences found for improvements status groups or for six-row barley and two-row barley. The Nordic accessions were shown to generally have high GPC when compared to control groups Karl and Lewis. However, even if the results of this study indicate that the HvNAM genes do not have major effects on the nutrient contents or GPC, Nordic barley might still be good material for plant improvement. Other factors such as other genes, environmental effects, and gene expression should therefore be investigated.

  • 1750.
    Österberg, Emmy
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Teknisk biologi. Linköpings universitet, Tekniska högskolan.
    Ro52: Structure and interactions of constructs of RING and B-box2014Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    The ubiquitination process is vital to maintain the protein homeostasis in the cell. With high specificity it regulates degradation of proteins by tagging them with a small protein called ubiquitin. Four proteins are involved to perform the process and in this thesis one of these proteins is studied. This protein is called Ro52 and belongs to the TRIM protein family. It posses E3 ligase activity because of a N-terminal RING-domain and therefore it is responsible for the last step in the ubiquitination process. The structure of Ro52 is not totally solved and the function of the protein’s four domains is not fully understood.

    In this thesis three constructs of two domains from Ro52 (RING and B-box) is investigated by circular dichroism (CD), nuclear magnetic resonance (NMR) spectroscopy and auto-ubiquitination assay by Western blot. The goal was to gain deeper insight in structural and functional properties of these domains.

    In the end only two constructs were investigated because of time limitations. It was shown by NMR that one construct has similar structure as the wild type but lower stability, possibly due to shorter N-terminal region. Comparison of the results from CD measurements showed that the constructs were well structured but did not reveal any significant differences in secondary structure between the constructs. Functional analysis by Western blot encountered unexpected problems and no results were obtained.

    The current thesis provides a basis for further investigation of variant constructs jointly expressing the RING-B-box domains, and shows that even small changes may alter structure and stability in ways that might affect functional properties. 

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