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  • 99051.
    Zhao, Q.X.
    et al.
    Linköping University.
    Yang, L.L.
    Linköping University.
    Willander, Magnus
    Linköping University.
    Pozina, G.
    Linköping University.
    Holtz, Per Olof
    Linköping University.
    Surface Recombination in ZnO Nanorods Grown by Aqueous Chemical Method2009In: Physics of Semiconductors, p. 1199-Article in journal (Refereed)
  • 99052.
    Zhao, Senlin
    et al.
    Shanghai Jiao Tong University, Peoples R China.
    Sun, Hongcheng
    Shanghai Jiao Tong University, Peoples R China.
    Jiang, Weiliang
    Shanghai Jiao Tong University, Peoples R China.
    Mi, Yushuai
    Shanghai Jiao Tong University, Peoples R China.
    Zhang, Dongyuan
    Shanghai Jiao Tong University, Peoples R China.
    Wen, Yugang
    Shanghai Jiao Tong University, Peoples R China.
    Cheng, Dantong
    Shanghai Jiao Tong University, Peoples R China.
    Tang, Huamei
    Shanghai Jiao Tong University, Peoples R China.
    Wu, Shaohan
    Jiaxing Coll, Peoples R China.
    Yu, Yang
    Shanghai Jiao Tong University, Peoples R China.
    Liu, Xisheng
    Shanghai Jiao Tong University, Peoples R China.
    Cui, Weiyingqi
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology.
    Zhang, Meng
    Fudan University, Peoples R China.
    Sun, Xiao-Feng
    Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology.
    Zhou, Zongguang
    Sichuan University, Peoples R China.
    Peng, Zhihai
    Shanghai Jiao Tong University, Peoples R China.
    Yan, Dongwang
    Shanghai Jiao Tong University, Peoples R China.
    miR-4775 promotes colorectal cancer invasion and metastasis via the Smad7/TGF beta-mediated epithelial to mesenchymal transition2017In: Molecular Cancer, ISSN 1476-4598, E-ISSN 1476-4598, Vol. 16, article id 12Article in journal (Refereed)
    Abstract [en]

    Background: Despite advancements in the diagnosis and treatment of colorectal cancer (CRC), many patients die because of tumor metastasis or recurrence. Therefore, identifying new prognostic markers and elucidating the mechanisms of CRC metastasis and recurrence will help to improve the prognosis of the disease. As dysregulation of microRNAs is strongly related to cancer progression, the aim of this study was to identify the role of miR-4775 in the prognosis of CRC patients and the underling mechanisms involved in CRC progression. Methods: qPCR and in situ hybridization were used to evaluate the expression of miR-4775 in 544 pairs of paraffin-embedded normal and CRC tissues. Kaplan-Meier analysis with the log-rank test was used for survival analyses. Immunohistochemical staining was applied to investigate the expression of miR-4775-regulated Smad7/TGF beta pathway-associated markers. In vitro and in vivo invasion and metastasis assays were used to explore the function of miR-4775 in the progression of CRC. Results: miR-4775 was identified as a high-risk factor for CRC metastasis and recurrence, with high levels predicting poor survival among the 544 studied CRC patients. Furthermore, high miR-4775 expression promoted the invasion of CRC cells as well as metastasis and the epithelial to mesenchymal transition (EMT) via Smad7-mediated activation of TGF beta signaling both in vitro and in vivo. Downregulating miR-4775 or overexpressing Smad7 reversed the tumor-promoting roles of miR-4775/ Smad7/TGF beta in vitro and in vivo. Conclusion: miR-4775 promotes CRC metastasis and recurrence in a Smad7/TGF beta signaling-dependent manner, providing a new therapeutic target for inhibiting the metastasis or recurrence of the disease.

  • 99053.
    Zhao, Wenchao
    et al.
    Chinese Academic Science, Peoples R China.
    Qian, Deping
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Zhang, Shaoqing
    Chinese Academic Science, Peoples R China.
    Li, Sunsun
    Chinese Academic Science, Peoples R China.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Gao, Feng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Hou, Jianhui
    Chinese Academic Science, Peoples R China.
    Fullerene-Free Polymer Solar Cells with over 11% Efficiency and Excellent Thermal Stability2016In: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 28, no 23, p. 4734-4739Article in journal (Refereed)
    Abstract [en]

    A nonfullerene-based polymer solar cell (PSC) that significantly outperforms fullerene-based PSCs with respect to the power-conversion efficiency is demonstrated for the first time. An efficiency of amp;gt;11%, which is among the top values in the PSC field, and excellent thermal stability is obtained using PBDB-T and ITIC as donor and acceptor, respectively.

  • 99054.
    ZHAO, Yang
    et al.
    Jilin University, Changchun, P. R. China.
    ZHANG, Feng-ling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    ZHANG, Ming
    Jilin University, Changchun, P. R. China.
    MA, Yu-guang
    Jilin University, Changchun, P. R. China.
    Characterization and properties of a new amorphous small-molecule material containing both donor and acceptor moieties for photovoltaic application2013In: Chemical Research in Chinese Universities, ISSN 1005-9040, E-ISSN 2210-3171, Vol. 29, no 6, p. 1193-1198Article in journal (Refereed)
    Abstract [en]

    A new amorphous small-molecule material, in which the electron-donating carbazole units are connected to the backbone by flexible side chains, has been synthesized and utilised in the photovoltaic(PV) field. This material exhibits the amorphous feature, higher thermal stability and good film forming ability. The influence of the heat-treatment on the morphology and the performance of PV devices were studied. Eventually, a relatively high photovoltaic conversion efficiency was achieved. At the same time, the PV device displayed an ideal open-circuit voltage(over 1 V) which is very close to the upper limit of its theoretical value.

  • 99055.
    Zhao, Yelin
    et al.
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Wang, Hui
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Gustafsson, Mika
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Muraro, Antonella
    University of Padua, Italy .
    Bruhn, Sören
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Benson, Mikael
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Combined Multivariate and Pathway Analyses Show That Allergen-Induced Gene Expression Changes in CD4(+) T Cells Are Reversed by Glucocorticoids2012In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, no 6Article in journal (Refereed)
    Abstract [en]

    Background: Glucocorticoids (GCs) play a key role in the treatment of allergy. However, the genome-wide effects of GCs on gene expression in allergen-challenged CD4(+) T cells have not been described. The aim of this study was to perform a genome-wide analysis to investigate whether allergen-induced gene expression changes in CD4(+) T cells could be reversed by GCs. Methodology/Principal Findings: Gene expression microarray analysis was performed to profile gene expression in diluent( D), allergen- (A), and allergen + hydrocortisone- (T) challenged CD4(+) T cells from patients with seasonal allergic rhinitis. Principal component analysis (PCA) showed good separation of the three groups. To identify the correlation between changes in gene expression in allergen-challenged CD4(+) T cells before and after GC treatment, we performed orthogonal partial least squares discriminant analysis (OPLS-DA) followed by Pearson correlation analysis. This revealed that allergen-induced genes were widely reversed by GC treatment (r = -0.77, Pless than0.0001). We extracted 547 genes reversed by GC treatment from OPLS-DA models based on their high contribution to the discrimination and found that those genes belonged to several different inflammatory pathways including TNFR2 Signalling, Interferon Signalling, Glucocorticoid Receptor Signalling and T Helper Cell Differentiation. The results were supported by gene expression microarray analyses of two independent materials. Conclusions/Significance: Allergen-induced gene expression changes in CD4(+) T cells were reversed by treatment with glucocorticoids. The top allergen-induced genes that reversed by GC treatment belonged to several inflammatory pathways and genes of known or potential relevance for allergy.

  • 99056.
    Zhao, Yidan
    Linköping University, Department of Computer and Information Science.
    An Improved Design and Implementation of the Session-based SAMBO with Parallelization Techniques and MongoDB2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The session-based SAMBO is an ontology alignment system involving MySQL to store matching results. Currently, SAMBO is able to align most ontologies within acceptable time. However, when it comes to large scale ontologies, SAMBO fails to reach the target. Thus, the main purpose of this thesis work is to improve the performance of SAMBO, especially in the case of matching large scale ontologies. 

    To reach the purpose, a comprehensive literature study and an investigation on two outstanding large scale ontology system are carried out with the aim of setting the improvement directions. A detailed investigation on the existing SAMBO is conducted to figure out in which aspects the system can be improved. Parallel matching process optimization and data management optimization are determined as the primary optimization goal of the thesis work. In the following, a few relevant techniques are studied and compared. Finally, an optimized design is proposed and implemented. 

    System testing results of the improved SAMBO show that both parallel matching process optimization and data management optimization contribute greatly to improve the performance of SAMBO. However the execution time of SAMBO to align large scale ontologies with database interaction is still unacceptable. 

  • 99057.
    Zhao, Yixin
    Linköping University, Department of Mathematics, Optimization . Linköping University, Faculty of Science & Engineering.
    On the Integration of Heuristics with Column-Oriented Models for Discrete Optimization2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Column-oriented models are today common in the eld of discrete optimization, and there is an increasing interest in using such models as a basis for heuristic solution methods. The common theme of this work is to explore some possibilities to integrate heuristic principles and column-oriented models for discrete optimization problems.

    In the rst paper, we consider a resource allocation problem for cellular systems. We propose a strong column-oriented formulation and a corresponding column generation method, as well as an enhanced column generation scheme for this problem. The enhanced scheme is composed of a stabilization technique, an approximate column generation principle, and, for nding integer solutions, a heuristic that is embedded in the column generation scheme.

    The second paper provides a new and strong convexied formulation of the xed charge transportation problem. This formulation is obtained by integrating the concepts of Lagrangian decomposition and column generation. It is shown both theoretically and practically that this integration yields a formulation which is stronger than three other convexied formulations of the problem.

    List of papers
    1. Power efficient uplink scheduling in SC-FDMA: benchmarking by column generation
    Open this publication in new window or tab >>Power efficient uplink scheduling in SC-FDMA: benchmarking by column generation
    Show others...
    2016 (English)In: Optimization and Engineering, ISSN 1389-4420, E-ISSN 1573-2924, Vol. 17, no 4, p. 695-725Article in journal (Refereed) Published
    Abstract [en]

    We study resource allocation in cellular systems and consider the problem of finding a power efficient scheduling in an uplink single carrier frequency division multiple access system. Due to the discrete nature of this problem and its computational difficulty, particularly in a real-time setting, the use of suboptimal algorithms is common practice. We aim at an effective way of gauging the performance of suboptimal algorithms by finding tight bounds on the global optimum. Toward this end, we first provide a basic integer linear programming formulation. Then we propose a significantly stronger column-oriented formulation and a corresponding column generation method, as well as an enhanced column generation scheme. The latter extends the first scheme through the inclusion of a stabilization technique, an approximate column generation principle, and a tailored heuristic that is embedded in the column generation scheme to find high-quality though not necessarily global optimal solutions. The computational evaluation demonstrates that compared with a poor performance by the integer linear programming formulation, the column generation method can produce near-optimal schedules that enable a sharp bounding interval. The enhanced column generation method significantly sharpens the bounding interval. Hence the column generation approach serves well for the purpose of benchmarking results for large-scale instances.

    Place, publisher, year, edition, pages
    Springer-Verlag New York, 2016
    Keywords
    Localized SC-FDMA, Stabilized column generation, Power minimization, Integer linear programming, Uplink scheduling, Matheuristic
    National Category
    Mathematics
    Identifiers
    urn:nbn:se:liu:diva-127355 (URN)10.1007/s11081-015-9304-z (DOI)000387857500004 ()
    Note

    Funding agencies: Research School in Interdisciplinary Mathematics at Linkoping University; Excellence Center at Linkoping - Lund in Information Technology, Centrum for Industriell Informationsteknologi, Linkoping University, EC FP7 Marie Curie Project [318992]; Chinese Sc

    Available from: 2016-04-22 Created: 2016-04-22 Last updated: 2019-08-06Bibliographically approved
    2. Power efficient uplink scheduling in SC-FDMA: Bounding global optimality by column generation
    Open this publication in new window or tab >>Power efficient uplink scheduling in SC-FDMA: Bounding global optimality by column generation
    Show others...
    2013 (English)In: 2013 IEEE 18th International Workshop on Computer Aided Modeling and Design of Communication Links and Networks (CAMAD, IEEE , 2013, p. 119-123Conference paper, Published paper (Refereed)
    Abstract [en]

    We study resource allocation in cellular systems and consider the problem of finding a power efficient scheduling in an uplink single carrier frequency division multiple access (SC-FDMA) system with localized allocation of subcarriers, that is, the subcarriers allocated to a user equipment have to be consecutive in the frequency domain in each time slot. This problem is discrete and nonconvex, thus the use of suboptimal algorithms has been a common practice. We leverage the power of mathematical programming in order to approach global optimality or a tight bounding interval confining global optimum, to arrive at an effective scheme for gauging the performance of suboptimal algorithms. Toward this end, we first provide a straightforward integer linear programming formulation, and then an alternative and less trivial, so-called column-oriented, formulation. The latter is solved by column generation, which is a solution technique for large-scale optimization problems with certain characteristics. The computational evaluation demonstrates that the column generation method produces very highquality subcarrier allocations that either coincide with the global optimum or enable an extremely sharp bounding interval. Hence the approach serves well for the purpose of benchmarking results for large-scale instances of power efficient SC-FDMA scheduling.

    Place, publisher, year, edition, pages
    IEEE, 2013
    Series
    International Workshop on Computer Aided Modeling and Design of Communication Links and Networks (CAMAD), ISSN 2378-4865 ; 2013
    National Category
    Mathematics
    Identifiers
    urn:nbn:se:liu:diva-106237 (URN)10.1109/CAMAD.2013.6708101 (DOI)
    Conference
    2013 IEEE 18th International Workshop on Computer Aided Modeling and Design of Communication Links and Networks (CAMAD)
    Available from: 2014-04-29 Created: 2014-04-29 Last updated: 2018-06-25
  • 99058.
    Zhao, Yixin
    et al.
    Linköping University, Department of Mathematics, Optimization . Linköping University, Faculty of Science & Engineering.
    Larsson, Torbjörn
    Linköping University, Department of Mathematics, Optimization . Linköping University, Faculty of Science & Engineering.
    Rönnberg, Elina
    Linköping University, Department of Mathematics, Optimization . Linköping University, Faculty of Science & Engineering.
    A Large Neighbourhood Search Principle for Column-Oriented Models: Theoretical Derivation and Example Applications2016In: Matheuristics 2016: Proceedings of the Sixth International Workshop on Model-based Metaheuristics / [ed] V. Maniezzo and T. Stutzle, Bruxelles, Belgium: IRIDIA , 2016Conference paper (Refereed)
  • 99059.
    Zhao, Yixin
    et al.
    Nanjing University of Science and Technology, School of Automation.
    Larsson, Torbjörn
    Linköping University, Department of Mathematics, Optimization . Linköping University, Faculty of Science & Engineering.
    Rönnberg, Elina
    Linköping University, Department of Mathematics, Optimization . Linköping University, Faculty of Science & Engineering.
    An integer programming column generation principlefor heuristic search methods2018In: International Transactions in Operational Research, ISSN 0969-6016, E-ISSN 1475-3995Article in journal (Refereed)
    Abstract [en]

    There is an increasing interest in integrating column generation and heuristic approaches to efficiently solve large-scale discrete optimisation problems. We contribute in this direction. Based on the insights from Lagrangian duality theory, we present an auxiliary problem that can be used for finding near-optimal solutions to a discrete column-oriented model. The structure of this auxiliary problem makes it suitable for being addressed with a heuristic search method involving column generation. To this end, we suggest a large neighbourhood search strategy where the repair step is to solve a column generation type subproblem. The suggested search strategy and mathematical models involved need to be tailored to the problem structure. To illustrate important design options and computational behaviour, four applications are studied: bin packing, generalised assignment, a resource allocation problem and the fixed-charge transportation problem.

  • 99060.
    Zhao, Yixin
    et al.
    Nanjing University of Science and Technology, School of Automation.
    Larsson, Torbjörn
    Linköping University, Department of Mathematics, Optimization . Linköping University, Faculty of Science & Engineering.
    Rönnberg, Elina
    Linköping University, Department of Mathematics, Optimization . Linköping University, Faculty of Science & Engineering.
    Pardalos, Panos
    University of Florida, Department of Industrial and System Engineering.
    The fixed charge transportation problem: a strong formulation based on Lagrangian decomposition and column generation2018In: Journal of Global Optimization, ISSN 0925-5001, E-ISSN 1573-2916, Vol. 72, no 3, p. 517-538Article in journal (Refereed)
    Abstract [en]

    A new and strong convexified formulation of the fixed charge transportation problem is provided. This formulation is obtained by integrating the concepts of Lagrangian decomposition and column generation. The decomposition is made by splitting the shipping variables into supply and demand side copies, while the columns correspond to extreme flow patterns for single sources or sinks. It is shown that the combination of Lagrangian decomposition and column generation provides a formulation whose strength dominates those of three other convexified formulations of the problem. Numerical results illustrate that our integrated approach has the ability to provide strong lower bounds. The Lagrangian decomposition yields a dual problem with an unbounded set of optimal solutions. We propose a regularized column generation scheme which prioritizes an optimal dual solution with a small 1-norm. We further demonstrate numerically that information gained from the strong formulation can also be used for constructing a small-sized core problem which yields high-quality upper bounds.

  • 99061.
    Zhao, Yixin
    et al.
    Nanjing Univ Sci and Technol, Peoples R China.
    Larsson, Torbjörn
    Linköping University, Department of Mathematics, Optimization . Linköping University, Faculty of Science & Engineering.
    Yuan, Di
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Rönnberg, Elina
    Linköping University, Department of Mathematics, Optimization . Linköping University, Faculty of Science & Engineering.
    Lei, Lei
    Linköping University, Department of Science and Technology. Linköping University, Faculty of Science & Engineering.
    Correction: Power efficient uplink scheduling in SC-FDMA: benchmarking by column generation (vol 17, pg 695, 2016)2019In: Optimization and Engineering, ISSN 1389-4420, E-ISSN 1573-2924, Vol. 20, no 3, p. 959-959Article in journal (Other academic)
    Abstract [en]

    At the time of the final publication of the paper, in December 2016, Yixin Zhaos affiliation had changed.

  • 99062.
    Zhao, Yixin
    et al.
    Linköping University, Department of Mathematics, Optimization . Linköping University, Faculty of Science & Engineering.
    Larsson, Torbjörn
    Linköping University, Department of Mathematics, Optimization . Linköping University, Faculty of Science & Engineering.
    Yuan, Di
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Rönnberg, Elina
    Linköping University, Department of Mathematics, Optimization . Linköping University, Faculty of Science & Engineering.
    Lei, Lei
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Power efficient uplink scheduling in SC-FDMA: benchmarking by column generation2016In: Optimization and Engineering, ISSN 1389-4420, E-ISSN 1573-2924, Vol. 17, no 4, p. 695-725Article in journal (Refereed)
    Abstract [en]

    We study resource allocation in cellular systems and consider the problem of finding a power efficient scheduling in an uplink single carrier frequency division multiple access system. Due to the discrete nature of this problem and its computational difficulty, particularly in a real-time setting, the use of suboptimal algorithms is common practice. We aim at an effective way of gauging the performance of suboptimal algorithms by finding tight bounds on the global optimum. Toward this end, we first provide a basic integer linear programming formulation. Then we propose a significantly stronger column-oriented formulation and a corresponding column generation method, as well as an enhanced column generation scheme. The latter extends the first scheme through the inclusion of a stabilization technique, an approximate column generation principle, and a tailored heuristic that is embedded in the column generation scheme to find high-quality though not necessarily global optimal solutions. The computational evaluation demonstrates that compared with a poor performance by the integer linear programming formulation, the column generation method can produce near-optimal schedules that enable a sharp bounding interval. The enhanced column generation method significantly sharpens the bounding interval. Hence the column generation approach serves well for the purpose of benchmarking results for large-scale instances.

  • 99063.
    Zhao, Yuxiao
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Combining RDF and OWL with SOAP for semantic web services2004In: Third Nordic Conference on Web Services NCWS, 2004, 2004, p. 31-45Conference paper (Other academic)
    Abstract [en]

    This paper has two contributions: (1) we attempt to propose that a combination of RDF and OWL with SOAP is useful for building semantic Web services (SWS); (2) we show how to combine them technically. A SOAP Envelope comprises Header (control data) and Body (transaction data). They are defined in XML schema syntactically not semantically, resulting in inflexibility for Web services invocation. RDF and OWL introduce ontology-based semantics into SOAP. We provide new SWS: three-level combinations plus a base level for easy comparison. SWS at Level 0 (Internal Translation) can process multiple data formats by internally translating one format in SOAP into others. SWS at Level 1 (Simple Reference) use pointing a link-with an OWL individual in SOAP and allow service receiver(s) to decide whether or not to process it. They are useful for such business use cases as product/ service introduction and promotion. SWS at Level 2 (Direct Embedment) embed an OWL individual in SOAP Envelope and define the types of messages in WSDL by using OWL classes instead of XML Schema. They are useful to add semantics gradually into current Web service infrastructure. SWS at Level 3 (Semantic SOAP) relax nearly all constraints in WSDL to receive/ send, understand, and process semantic SOAP, encoded in a general ontology. They are useful for casual integration and for agents that have never communicated before.

  • 99064.
    Zhao, Yuxiao
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Develop the ontology for internet commerce by reusing existing standards2003In: Proceedings of International Workshop on Semantic Web Foundations and Applications Technologies (SWFAT), 2003, p. 51-57Conference paper (Refereed)
    Abstract [en]

    This paper attempts to present an approach to develop the ontology for Internet commerce by reusing the vocabulary from the existing standards, industry initiatives or XML-based frameworks. The approach allows ontology developers to share the common vocabulary and build it from a solid foundation. The paper includes two main contributions: 1. an approach to develop the ontology for the domain of Internet commerce; 2. the guidelines about what vocabulary can be reused from the existing standards.

  • 99065.
    Zhao, Yuxiao
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Standards-based application integration for business-to-business communications2005Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Fierce competitions and pursuits of excellence require all applications, internal or external, to be integrated for business-to-business communications. Standards play an important role in fulfilling the requirement. This dissertation focuses on Business-to-Business standards or XML-based frameworks for Internet commerce

    First, we analyze what the standards are and how they interact. Fifteen influential standards are selected: eCo Framework, ebXML, UBL, UDDI, SOAP, WSDL, RosettaNet, Open Applications Group, VoiceXML, cXML, Wf-XML, OFX, ICE, RDF, and OWL. Basically each standard has to provide transport mechanisms and message structures for general and/or specific applications. In terms of message structure definition, they can be classified as two types: syntax-based, for defining messages syntactically and semantics-based, like RDF and OWL for defining messages semantically.

    Second, for transiting from syntax to semantics, we provide a reuse-based method to develop the ontology by reusing existing XML-based standards. This is a kind of knowledge reuse, for instance, using previously developed structures, naming conventions and relationships between concepts.

    Third, we exploit how to use these standards. We propose an approach that combines RDF and OWL with SOAP for building semantic Web services. Three levels of combinations are provided: Simple Reference, Direct Embedment, and Semantic SOAP.

    Fourth, we design an infrastructure aimed at creating a formal channel by using Web services and semantic Web for establishing buyer awareness, i.e., buyers first become aware of products/promotions offered by sellers. We propose the concept of personal ontology, emphasizing that ontology is not only a common and shared conceptualization but also can be used to specify personal views of the products by sellers and buyers. The agreements between buyers and sellers can be described in XML schema or ontology in OWL. A semantic matchmaking algorithm is designed and implemented considering synonym, polysemy and partial matching.

    List of papers
    1. XML-based frameworks for internet commerce
    Open this publication in new window or tab >>XML-based frameworks for internet commerce
    2001 (English)In: Enterprise Information Systems II / [ed] B. Sharp, Joaquim Filipe, José Cordeiro, 2001, p. 197-202Conference paper, Published paper (Other academic)
    Abstract [en]

    XML-based frameworks or industry standards for Internet Commerce are rapidly launched and changed. The contribution of this paper is to increase the understanding and facilitate comparison and evaluation of the most commonly referred frameworks. The paper provides a survey of the architecture and message definition of BizTalk, cXML, eCo Framework, ICE (Information and Content Exchange), IOTP (Internet Open Trading Protocol), OAG (Open Applications Group), RosettaNet, xCBL, ebXML and ontology.org. The relationships between these frameworks are cooperative and competitive and thus the merger and change are unavoidable. At present eCo Framework and xCBL are tightly cooperative and supported by others. The competing initiative is centered around Microsoft's BizTalk, supported by cXML and OAG. The future will probably see closer cooperation to make formats compatible. Microsoft is both promoting BizTalk and is a member of eCo Framework.

    Keywords
    XML, Framework, Industry Standard, E-Commerce, Internet Commerce
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-85537 (URN)0-7923-7177-1 (ISBN)
    Conference
    International Conference on Enterprise Information Systems (ICEIS), Stafford, the Uk, Jul 5-7, 2000
    Available from: 2012-11-22 Created: 2012-11-22 Last updated: 2012-11-22
    2. Potential advantages of semantic web for internet commerce
    Open this publication in new window or tab >>Potential advantages of semantic web for internet commerce
    2003 (English)In: Fifth International Conference on Enterprise Information Systems. Proceedings, 2003, p. 151-158Conference paper, Published paper (Refereed)
    Abstract [en]

    Past decade saw much hype in the area of information technology. The emerging of semantic Web makes us ask if it is another hype. This paper focuses on its potential application in Internet commerce and intends to answer the question to some degree. The contributions are: first, we find and examine twelve potential advantages of applying semantic Web for Internet commerce; second, we conduct a case study of e-procurement in order to show its advantages for each process of e-procurement; lastly, we identify critical research issues that may transfer the potential advantages into tangible benefits.

    Keywords
    Semantic Web, Internet commerce, Application
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-60458 (URN)
    Conference
    International Conference on Enterprise Information Systems (ICEIS), Angers, France, Apr 23-26, 2003
    Available from: 2010-10-13 Created: 2010-10-13 Last updated: 2012-11-22
    3. Develop the ontology for internet commerce by reusing existing standards
    Open this publication in new window or tab >>Develop the ontology for internet commerce by reusing existing standards
    2003 (English)In: Proceedings of International Workshop on Semantic Web Foundations and Applications Technologies (SWFAT), 2003, p. 51-57Conference paper, Published paper (Refereed)
    Abstract [en]

    This paper attempts to present an approach to develop the ontology for Internet commerce by reusing the vocabulary from the existing standards, industry initiatives or XML-based frameworks. The approach allows ontology developers to share the common vocabulary and build it from a solid foundation. The paper includes two main contributions: 1. an approach to develop the ontology for the domain of Internet commerce; 2. the guidelines about what vocabulary can be reused from the existing standards.

    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-61613 (URN)
    Conference
    International Workshop on Semantic Web Foundations and Application Technologies (SWFAT), Nara, Japan, March 12, 2003
    Available from: 2010-11-17 Created: 2010-11-17 Last updated: 2012-11-22
    4. A reuse-based method of developing the ontology for e-procurement
    Open this publication in new window or tab >>A reuse-based method of developing the ontology for e-procurement
    2003 (English)In: Proc Second Nordic Conference on Web Services (NCWS'2003), 2003, p. 101-112Conference paper, Published paper (Refereed)
    Abstract [en]

    We propose a reuse-based method for ontology development by exploiting the similarities in the structures of XML documents and ontology. We apply the method to write the ontology for e-procurement with OWL, which spans the trading cycle: Order, OrderResponse, OrderCancellation, DispatchAdvice, ReceiptAdvice and Invoice. The paper consists of four contributions: 1. An analysis of the ontology types for Internet commerce; 2. An illustration of how to reuse existing XML-based standards including reuses of architecture, XML Schema and other standards; 3. A tool presented to validate if an instance is consistent with the ontology; 4. Three issues are discussed: applicability of the method, the hardest things by our experiences and tools needed to support the method. Meanwhile, this research also shows previous investments on XML in industry are very useful for the corresponding ontology development.

    National Category
    Computer Sciences
    Identifiers
    urn:nbn:se:liu:diva-62129 (URN)91-7636-392-9 (ISBN)
    Conference
    2nd Nordic Conference on Web Services (NCWS), Växsjö, Sweden, Nov 20-21, 2003
    Available from: 2010-11-19 Created: 2010-11-19 Last updated: 2018-01-12
    5. Combining RDF and OWL with SOAP for semantic web services
    Open this publication in new window or tab >>Combining RDF and OWL with SOAP for semantic web services
    2004 (English)In: Third Nordic Conference on Web Services NCWS, 2004, 2004, p. 31-45Conference paper, Published paper (Other academic)
    Abstract [en]

    This paper has two contributions: (1) we attempt to propose that a combination of RDF and OWL with SOAP is useful for building semantic Web services (SWS); (2) we show how to combine them technically. A SOAP Envelope comprises Header (control data) and Body (transaction data). They are defined in XML schema syntactically not semantically, resulting in inflexibility for Web services invocation. RDF and OWL introduce ontology-based semantics into SOAP. We provide new SWS: three-level combinations plus a base level for easy comparison. SWS at Level 0 (Internal Translation) can process multiple data formats by internally translating one format in SOAP into others. SWS at Level 1 (Simple Reference) use pointing a link-with an OWL individual in SOAP and allow service receiver(s) to decide whether or not to process it. They are useful for such business use cases as product/ service introduction and promotion. SWS at Level 2 (Direct Embedment) embed an OWL individual in SOAP Envelope and define the types of messages in WSDL by using OWL classes instead of XML Schema. They are useful to add semantics gradually into current Web service infrastructure. SWS at Level 3 (Semantic SOAP) relax nearly all constraints in WSDL to receive/ send, understand, and process semantic SOAP, encoded in a general ontology. They are useful for casual integration and for agents that have never communicated before.

    National Category
    Computer Sciences
    Identifiers
    urn:nbn:se:liu:diva-23087 (URN)2479 (Local ID)2479 (Archive number)2479 (OAI)
    Conference
    3rd Nordic Conference on Webservices (NCWS), Växsjö, Sweden, Nov 22-23
    Available from: 2009-10-07 Created: 2009-10-07 Last updated: 2018-01-13
    6. An infrastructure for establishing buyer awareness by using Web services and semantic Web
    Open this publication in new window or tab >>An infrastructure for establishing buyer awareness by using Web services and semantic Web
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Establishing buyer awareness contains two major business processes: (1) sellers advertise their products and (2) buyers become aware of them or first learn of them. On the Internet, e-mail is the major means by using messaging for realizing buyer awareness, but critical challenges are ahead from the perspectives of legitimacy and efficiency. This paper provides an infrastructure for establishing buyer awareness, called SAMI (Specification, Agreement, and Matchmaking Infrastructure), enabling all  sellers' advertisements to formally reach potential buyers instead of being unread. Under the SAMI, sellers and buyers need to adjust to each other: (1) buyers should launch their Web services to recieve sellers' advertisements and install their own agents to process all of them and (2) sellers should specify their products simply but with rich semantics that the agents can process instead of using natural language which is relatively hard to process. Three contributions are included. First, the concept of personal ontology is defined for sellers and buyers to add rich semantics into their keywords for semantic matchmaking. Second, an ontology as well as an  XML Schema is designed for encoding messages for simplifying for agreement of messaging. Third, an algorithm is provided to match buyers' keywords (requirements) with sellers' keywords (advertisments) with regard to synonym, polysemy and partial matching. In particular all keywords can be any classes or instances from different ontologies. A prototype system has been implemented and tested

    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-85538 (URN)
    Available from: 2012-11-22 Created: 2012-11-22 Last updated: 2012-11-22
  • 99066.
    Zhao, Yuxiao
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    XML-based frameworks for Internet commerce and an implementation of B2B e-procurement2001Licentiate thesis, monograph (Other academic)
    Abstract [en]

    It is not easy to apply XML in e-commerce development for achieving interoperability in heterogeneous environments. One of the reasons is a multitude of XML-based Frameworks for Internet Commerce (XFIC), or industrial standards. This thesis surveys 15 frameworks, i.e., ebXML, eCo Framework, UDDI, SOAP, BizTalk, cXML, ICE, Open Applications Group, RosettaNet, Wf-XML, OFX, VoiceXML, RDF, WSDL and xCBL.

    This thesis provides three models to systematically understand how the 15 frameworks meet the requirements of e-commerce. A hierarchical model is presented to show the purpose and focus of various XFIC initiatives. A relationship model is given to show the cooperative and competitive relationships between XFIC. A chronological model is provided to look at the development of XFIC. In addition, the thesis offers guidelines for how to apply XFIC in an e-commerce development.

    We have also implemented a B2B e-procurement system. That not only demonstrates the feasibility of opensource or freeware, but also validates the complementary roles of XML and Java: XML is for describing contents and Java is for automating XML documents (session handling). Auction-based dynamic pricing is also realized as a feature of interest. Moreover, the implementation shows the suitability of e-procurement for educational purposes in e-commerce development.

  • 99067.
    Zhao, Yuxiao
    et al.
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Lövdahl, Johan
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    A reuse-based method of developing the ontology for e-procurement2003In: Proc Second Nordic Conference on Web Services (NCWS'2003), 2003, p. 101-112Conference paper (Refereed)
    Abstract [en]

    We propose a reuse-based method for ontology development by exploiting the similarities in the structures of XML documents and ontology. We apply the method to write the ontology for e-procurement with OWL, which spans the trading cycle: Order, OrderResponse, OrderCancellation, DispatchAdvice, ReceiptAdvice and Invoice. The paper consists of four contributions: 1. An analysis of the ontology types for Internet commerce; 2. An illustration of how to reuse existing XML-based standards including reuses of architecture, XML Schema and other standards; 3. A tool presented to validate if an instance is consistent with the ontology; 4. Three issues are discussed: applicability of the method, the hardest things by our experiences and tools needed to support the method. Meanwhile, this research also shows previous investments on XML in industry are very useful for the corresponding ontology development.

  • 99068.
    Zhao, Yuxiao
    et al.
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Sandahl, Kristian
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Potential advantages of semantic web for internet commerce2003In: Fifth International Conference on Enterprise Information Systems. Proceedings, 2003, p. 151-158Conference paper (Refereed)
    Abstract [en]

    Past decade saw much hype in the area of information technology. The emerging of semantic Web makes us ask if it is another hype. This paper focuses on its potential application in Internet commerce and intends to answer the question to some degree. The contributions are: first, we find and examine twelve potential advantages of applying semantic Web for Internet commerce; second, we conduct a case study of e-procurement in order to show its advantages for each process of e-procurement; lastly, we identify critical research issues that may transfer the potential advantages into tangible benefits.

  • 99069.
    Zhao, Yuxiao
    et al.
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Sandahl, Kristian
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    XML-based frameworks for internet commerce2001In: Enterprise Information Systems II / [ed] B. Sharp, Joaquim Filipe, José Cordeiro, 2001, p. 197-202Conference paper (Other academic)
    Abstract [en]

    XML-based frameworks or industry standards for Internet Commerce are rapidly launched and changed. The contribution of this paper is to increase the understanding and facilitate comparison and evaluation of the most commonly referred frameworks. The paper provides a survey of the architecture and message definition of BizTalk, cXML, eCo Framework, ICE (Information and Content Exchange), IOTP (Internet Open Trading Protocol), OAG (Open Applications Group), RosettaNet, xCBL, ebXML and ontology.org. The relationships between these frameworks are cooperative and competitive and thus the merger and change are unavoidable. At present eCo Framework and xCBL are tightly cooperative and supported by others. The competing initiative is centered around Microsoft's BizTalk, supported by cXML and OAG. The future will probably see closer cooperation to make formats compatible. Microsoft is both promoting BizTalk and is a member of eCo Framework.

  • 99070.
    Zhao, Yuxiao
    et al.
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Sandahl, Kristina
    Linköping University, Department of Computer and Information Science. Linköping University, The Tema Institute.
    An infrastructure for establishing buyer awareness by using Web services and semantic WebManuscript (preprint) (Other academic)
    Abstract [en]

    Establishing buyer awareness contains two major business processes: (1) sellers advertise their products and (2) buyers become aware of them or first learn of them. On the Internet, e-mail is the major means by using messaging for realizing buyer awareness, but critical challenges are ahead from the perspectives of legitimacy and efficiency. This paper provides an infrastructure for establishing buyer awareness, called SAMI (Specification, Agreement, and Matchmaking Infrastructure), enabling all  sellers' advertisements to formally reach potential buyers instead of being unread. Under the SAMI, sellers and buyers need to adjust to each other: (1) buyers should launch their Web services to recieve sellers' advertisements and install their own agents to process all of them and (2) sellers should specify their products simply but with rich semantics that the agents can process instead of using natural language which is relatively hard to process. Three contributions are included. First, the concept of personal ontology is defined for sellers and buyers to add rich semantics into their keywords for semantic matchmaking. Second, an ontology as well as an  XML Schema is designed for encoding messages for simplifying for agreement of messaging. Third, an algorithm is provided to match buyers' keywords (requirements) with sellers' keywords (advertisments) with regard to synonym, polysemy and partial matching. In particular all keywords can be any classes or instances from different ontologies. A prototype system has been implemented and tested

  • 99071.
    Zhao, Yuxin
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, Faculty of Science & Engineering.
    Gaussian Processes for Positioning Using Radio Signal Strength Measurements2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Estimation of unknown parameters is considered as one of the major research areas in statistical signal processing. In the most recent decades, approaches in estimation theory have become more and more attractive in practical applications. Examples of such applications may include, but are not limited to, positioning using various measurable radio signals in indoor environments, self-navigation for autonomous cars, image processing, radar tracking and so on. One issue that is usually encountered when solving an estimation problem is to identify a good system model, which may have great impacts on the estimation performance. In this thesis, we are interested in studying estimation problems particularly in inferring the unknown positions from noisy radio signal measurements. In addition, the modeling of the system is studied by investigating the relationship between positions and radio signal strength measurements.

    One of the main contributions of this thesis is to propose a novel indoor positioning framework based on proximity measurements, which are obtained by quantizing the received signal strength measurements. Sequential Monte Carlo methods, to be more specific particle filter and smoother, are utilized for estimating unknown positions from proximity measurements. The Cramér-Rao bounds for proximity-based positioning are further derived as a benchmark for the positioning accuracy in this framework.

    Secondly, to improve the estimation performance, Bayesian non-parametric modeling, namely Gaussian processes, have been adopted to provide more accurate and flexible models for both dynamic motions and radio signal strength measurements. Then, the Cramér-Rao bounds for Gaussian process based system models are derived and evaluated in an indoor positioning scenario.

    In addition, we estimate the positions of stationary devices by comparing the individual signal strength measurements with a pre-constructed fingerprinting database. The positioning accuracy is further compared to the case where a moving device is positioned using a time series of radio signal strength measurements.

    Moreover, Gaussian processes have been applied to sports analytics, where trajectory modeling for athletes is studied. The proposed framework can be further utilized to carry out, for instance, performance prediction and analysis, health condition monitoring, etc. Finally, a grey-box modeling is proposed to analyze the forces, particularly in cross-country skiing races, by combining a deterministic kinetic model with Gaussian process.

    List of papers
    1. Received-Signal-Strength Threshold Optimization Using Gaussian Processes
    Open this publication in new window or tab >>Received-Signal-Strength Threshold Optimization Using Gaussian Processes
    2017 (English)In: IEEE Transactions on Signal Processing, ISSN 1053-587X, E-ISSN 1941-0476, Vol. 65, no 8, p. 2164-2177Article in journal (Refereed) Published
    Abstract [en]

    There is a big trend nowadays to use event-triggered proximity report for indoor positioning. This paper presents a generic received-signal-strength (RSS) threshold optimization framework for generating informative proximity reports. The proposed framework contains five main building blocks, namely the deployment information, RSS model, positioning metric selection, optimization process and management. Among others, we focus on Gaussian process regression (GPR)-based RSS models and positioning metric computation. The optimal RSS threshold is found through minimizing the best achievable localization root-mean-square-error formulated with the aid of fundamental lower bound analysis. Computational complexity is compared for different RSS models and different fundamental lower bounds. The resulting optimal RSS threshold enables enhanced performance of new fashioned low-cost and low-complex proximity report-based positioning algorithms. The proposed framework is validated with real measurements collected in an office area where bluetooth-low-energy (BLE) beacons are deployed.

    Place, publisher, year, edition, pages
    Institute of Electrical and Electronics Engineers (IEEE), 2017
    National Category
    Electrical Engineering, Electronic Engineering, Information Engineering
    Identifiers
    urn:nbn:se:liu:diva-135065 (URN)10.1109/TSP.2017.2655480 (DOI)000395827100018 ()
    Projects
    TRAX
    Note

    Funding agencies: European Union FP7 Marie Curie training programme on Tracking in Complex Sensor Systems [607400]

    Available from: 2017-03-08 Created: 2017-03-08 Last updated: 2019-02-12Bibliographically approved
    2. Sequential Monte Carlo Methods and Theoretical Bounds for Proximity Report Based Indoor Positioning
    Open this publication in new window or tab >>Sequential Monte Carlo Methods and Theoretical Bounds for Proximity Report Based Indoor Positioning
    Show others...
    2018 (English)In: IEEE Transactions on Vehicular Technology, ISSN 0018-9545, E-ISSN 1939-9359, Vol. 67, no 6, p. 5372-5386Article in journal (Refereed) Published
    Abstract [en]

    The commercial interest in proximity services is increasing. Application examples include location-based information and advertisements, logistics, social networking, file sharing, etc. In this paper, we consider positioning of devices based on a time series of proximity reports from a mobile device to a network node. This corresponds to nonlinear measurements with respect to the device position in relation to the network nodes. Motion model will be needed together with the measurements to determine the position of the device. Therefore, sequential Monte Carlo methods, namely particle filtering and smoothing, are applicable for positioning. Positioning performance is evaluated in a typical office area with Bluetooth-low-energy beacons deployed for proximity detection and report, and is further compared to parametric Cramér-Rao lower bounds. Finally, the position accuracy is also evaluated with real experimental data.

    Place, publisher, year, edition, pages
    Institute of Electrical and Electronics Engineers (IEEE), 2018
    Keywords
    Proximity, indoor positioning, particle filtering and smoothing, Cramer-Rao lower bounds
    National Category
    Signal Processing
    Identifiers
    urn:nbn:se:liu:diva-147834 (URN)10.1109/TVT.2018.2799174 (DOI)000435553400053 ()2-s2.0-85041415767 (Scopus ID)
    Note

    Funding agencies: European Union FP7 Marie Curie Training Programme on Tracking in Complex Sensor Systems (TRAX) [607400]; NSFC [61701426]; Shenzhen Science and Technology Innovation Council [JCYJ20170307155957688, JCYJ20170411102101881]

    Available from: 2018-05-15 Created: 2018-05-15 Last updated: 2019-02-12Bibliographically approved
    3. Gaussian Process for Propagation modeling and Proximity Reports Based Indoor Positioning
    Open this publication in new window or tab >>Gaussian Process for Propagation modeling and Proximity Reports Based Indoor Positioning
    Show others...
    2016 (English)In: 2016 IEEE 83rd Vehicular Technology Conference (VTC Spring), IEEE , 2016, p. 1-5Conference paper, Published paper (Refereed)
    Abstract [en]

    The commercial interest in proximity services is increasing. Application examples include location-based information and advertisements, logistics, social networking, file sharing, etc. In this paper, we consider network-based positioning based on times series of proximity reports from a mobile device, either only a proximity indicator, or a vector of RSS from observed nodes. Such positioning corresponds to a latent and nonlinear observation model. To address these problems, we combine two powerful tools, namely particle filtering and Gaussian process regression (GPR) for radio signal propagation modeling. The latter also provides some insights into the spatial correlation of the radio propagation in the considered area. Radio propagation modeling and positioning performance are evaluated in a typical office area with Bluetooth-Low-Energy (BLE) beacons deployed for proximity detection and reports. Results show that the positioning accuracy can be improved by using GPR.

    Place, publisher, year, edition, pages
    IEEE, 2016
    National Category
    Communication Systems
    Identifiers
    urn:nbn:se:liu:diva-128255 (URN)10.1109/VTCSpring.2016.7504255 (DOI)000386528400206 ()9781509016983 (ISBN)
    Conference
    2016 IEEE 83rd Vehicular Technology Conference: VTC2016-Spring, 15–18 May 2016, Nanjing, China
    Available from: 2016-05-24 Created: 2016-05-24 Last updated: 2019-02-12Bibliographically approved
    4. Gaussian processes for RSS fingerprints construction in indoor localization
    Open this publication in new window or tab >>Gaussian processes for RSS fingerprints construction in indoor localization
    2018 (English)In: 21st International Conference on Information Fusion (FUSION), IEEE, 2018, p. 1377-1384Conference paper, Published paper (Refereed)
    Abstract [en]

    Location-based applications attract more and more attention in recent years. Examples of such applications include commercial advertisements, social networking software and patient monitoring. The received signal strength (RSS) based location fingerprinting is one of the most popular solutions for indoor localization. However, there is a big challenge in collecting and maintaining a relatively large RSS fingerprint database. In this work, we propose and compare two algorithms namely, the Gaussian process (GP) and Gaussian process with variogram, to estimate and construct the RSS fingerprints with incomplete data. The fingerprint of unknown reference points is estimated based on measurements at a limited number of surrounding locations. To validate the effectiveness of both algorithms, experiments using Bluetooth-low-energy (BLE) infrastructure have been conducted. The constructed RSS fingerprints are compared to the true measurements, and the result is analyzed. Finally, using the constructed fingerprints, the localization performance of a probabilistic fingerprinting method is evaluated.

    Place, publisher, year, edition, pages
    IEEE, 2018
    National Category
    Signal Processing
    Identifiers
    urn:nbn:se:liu:diva-151693 (URN)10.23919/ICIF.2018.8455842 (DOI)978-0-9964527-6-2 (ISBN)
    Conference
    21st International Conference on Information Fusion (FUSION), 10-13 July 2018, Cambridge, UK
    Available from: 2018-10-01 Created: 2018-10-01 Last updated: 2019-02-12
    5. Gaussian Processes for Flow Modeling and Prediction of Positioned Trajectories Evaluated with Sports Data
    Open this publication in new window or tab >>Gaussian Processes for Flow Modeling and Prediction of Positioned Trajectories Evaluated with Sports Data
    Show others...
    2016 (English)In: 19th International Conference on  Information Fusion (FUSION), 2016, Institute of Electrical and Electronics Engineers (IEEE), 2016, p. 1461-1468Conference paper, Published paper (Refereed)
    Abstract [en]

    Kernel-based machine learning methods are gaining increasing interest in flow modeling and prediction in recent years. Gaussian process (GP) is one example of such kernelbased methods, which can provide very good performance for nonlinear problems. In this work, we apply GP regression to flow modeling and prediction of athletes in ski races, but the proposed framework can be generally applied to other use cases with device trajectories of positioned data. Some specific aspects can be addressed when the data is periodic, like in sports where the event is split up over multiple laps along a specific track. Flow models of both the individual skier and a cluster of skiers are derived and analyzed. Performance has been evaluated using data from the Falun Nordic World Ski Championships 2015, in particular the Men’s cross country 4 × 10 km relay. The results show that the flow models vary spatially for different skiers and clusters. We further demonstrate that GP regression provides powerful and accurate models for flow prediction.

    Place, publisher, year, edition, pages
    Institute of Electrical and Electronics Engineers (IEEE), 2016
    National Category
    Electrical Engineering, Electronic Engineering, Information Engineering Probability Theory and Statistics
    Identifiers
    urn:nbn:se:liu:diva-129758 (URN)9780996452748 (ISBN)9781509020126 (ISBN)
    Conference
    19th International Conference on Information Fusion, 5-8 July 2016, Heidelberg, Germany
    Available from: 2016-06-27 Created: 2016-06-27 Last updated: 2019-02-12Bibliographically approved
  • 99072.
    Zhao, Yuxin
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, Faculty of Science & Engineering.
    Position Estimation in Uncertain Radio Environments and Trajectory Learning2017Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    To infer the hidden states from the noisy observations and make predictions based on a set of input states and output observations are two challenging problems in many research areas. Examples of applications many include position estimation from various measurable radio signals in indoor environments, self-navigation for autonomous cars, modeling and predicting of the traffic flows, and flow pattern analysis for crowds of people. In this thesis, we mainly use the Bayesian inference framework for position estimation in an indoor environment, where the radio propagation is uncertain. In Bayesian inference framework, it is usually hard to get analytical solutions. In such cases, we resort to Monte Carlo methods to solve the problem numerically. In addition, we apply Bayesian nonparametric modeling for trajectory learning in sport analytics.

    The main contribution of this thesis is to propose sequential Monte Carlo methods, namely particle filtering and smoothing, for a novel indoor positioning framework based on proximity reports. The experiment results have been further compared with theoretical bounds derived for this proximity based positioning system. To improve the performance, Bayesian non-parametric modeling, namely Gaussian process, has been applied to better indicate the radio propagation conditions. Then, the position estimates obtained sequentially using filtering and smoothing are further compared with a static solution, which is known as fingerprinting.

    Moreover, we propose a trajectory learning framework for flow estimation in sport analytics based on Gaussian processes. To mitigate the computation deficiency of Gaussian process, a grid-based on-line algorithm has been adopted for real-time applications. The resulting trajectory modeling for individual athlete can be used for many purposes, such as performance prediction and analysis, health condition monitoring, etc. Furthermore, we aim at modeling the flow of groups of athletes, which could be potentially used for flow pattern recognition, strategy planning, etc.

    List of papers
    1. Received-Signal-Strength Threshold Optimization Using Gaussian Processes
    Open this publication in new window or tab >>Received-Signal-Strength Threshold Optimization Using Gaussian Processes
    2017 (English)In: IEEE Transactions on Signal Processing, ISSN 1053-587X, E-ISSN 1941-0476, Vol. 65, no 8, p. 2164-2177Article in journal (Refereed) Published
    Abstract [en]

    There is a big trend nowadays to use event-triggered proximity report for indoor positioning. This paper presents a generic received-signal-strength (RSS) threshold optimization framework for generating informative proximity reports. The proposed framework contains five main building blocks, namely the deployment information, RSS model, positioning metric selection, optimization process and management. Among others, we focus on Gaussian process regression (GPR)-based RSS models and positioning metric computation. The optimal RSS threshold is found through minimizing the best achievable localization root-mean-square-error formulated with the aid of fundamental lower bound analysis. Computational complexity is compared for different RSS models and different fundamental lower bounds. The resulting optimal RSS threshold enables enhanced performance of new fashioned low-cost and low-complex proximity report-based positioning algorithms. The proposed framework is validated with real measurements collected in an office area where bluetooth-low-energy (BLE) beacons are deployed.

    Place, publisher, year, edition, pages
    Institute of Electrical and Electronics Engineers (IEEE), 2017
    National Category
    Electrical Engineering, Electronic Engineering, Information Engineering
    Identifiers
    urn:nbn:se:liu:diva-135065 (URN)10.1109/TSP.2017.2655480 (DOI)000395827100018 ()
    Projects
    TRAX
    Note

    Funding agencies: European Union FP7 Marie Curie training programme on Tracking in Complex Sensor Systems [607400]

    Available from: 2017-03-08 Created: 2017-03-08 Last updated: 2019-02-12Bibliographically approved
    2. Gaussian Process for Propagation modeling and Proximity Reports Based Indoor Positioning
    Open this publication in new window or tab >>Gaussian Process for Propagation modeling and Proximity Reports Based Indoor Positioning
    Show others...
    2016 (English)In: 2016 IEEE 83rd Vehicular Technology Conference (VTC Spring), IEEE , 2016, p. 1-5Conference paper, Published paper (Refereed)
    Abstract [en]

    The commercial interest in proximity services is increasing. Application examples include location-based information and advertisements, logistics, social networking, file sharing, etc. In this paper, we consider network-based positioning based on times series of proximity reports from a mobile device, either only a proximity indicator, or a vector of RSS from observed nodes. Such positioning corresponds to a latent and nonlinear observation model. To address these problems, we combine two powerful tools, namely particle filtering and Gaussian process regression (GPR) for radio signal propagation modeling. The latter also provides some insights into the spatial correlation of the radio propagation in the considered area. Radio propagation modeling and positioning performance are evaluated in a typical office area with Bluetooth-Low-Energy (BLE) beacons deployed for proximity detection and reports. Results show that the positioning accuracy can be improved by using GPR.

    Place, publisher, year, edition, pages
    IEEE, 2016
    National Category
    Communication Systems
    Identifiers
    urn:nbn:se:liu:diva-128255 (URN)10.1109/VTCSpring.2016.7504255 (DOI)000386528400206 ()9781509016983 (ISBN)
    Conference
    2016 IEEE 83rd Vehicular Technology Conference: VTC2016-Spring, 15–18 May 2016, Nanjing, China
    Available from: 2016-05-24 Created: 2016-05-24 Last updated: 2019-02-12Bibliographically approved
    3. Gaussian Processes for Flow Modeling and Prediction of Positioned Trajectories Evaluated with Sports Data
    Open this publication in new window or tab >>Gaussian Processes for Flow Modeling and Prediction of Positioned Trajectories Evaluated with Sports Data
    Show others...
    2016 (English)In: 19th International Conference on  Information Fusion (FUSION), 2016, Institute of Electrical and Electronics Engineers (IEEE), 2016, p. 1461-1468Conference paper, Published paper (Refereed)
    Abstract [en]

    Kernel-based machine learning methods are gaining increasing interest in flow modeling and prediction in recent years. Gaussian process (GP) is one example of such kernelbased methods, which can provide very good performance for nonlinear problems. In this work, we apply GP regression to flow modeling and prediction of athletes in ski races, but the proposed framework can be generally applied to other use cases with device trajectories of positioned data. Some specific aspects can be addressed when the data is periodic, like in sports where the event is split up over multiple laps along a specific track. Flow models of both the individual skier and a cluster of skiers are derived and analyzed. Performance has been evaluated using data from the Falun Nordic World Ski Championships 2015, in particular the Men’s cross country 4 × 10 km relay. The results show that the flow models vary spatially for different skiers and clusters. We further demonstrate that GP regression provides powerful and accurate models for flow prediction.

    Place, publisher, year, edition, pages
    Institute of Electrical and Electronics Engineers (IEEE), 2016
    National Category
    Electrical Engineering, Electronic Engineering, Information Engineering Probability Theory and Statistics
    Identifiers
    urn:nbn:se:liu:diva-129758 (URN)9780996452748 (ISBN)9781509020126 (ISBN)
    Conference
    19th International Conference on Information Fusion, 5-8 July 2016, Heidelberg, Germany
    Available from: 2016-06-27 Created: 2016-06-27 Last updated: 2019-02-12Bibliographically approved
  • 99073.
    Zhao, Yuxin
    et al.
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, Faculty of Science & Engineering.
    Fritsche, Carsten
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, Faculty of Science & Engineering.
    Supplementary Materials for "Sequential Monte Carlo Methods and Theoretical Bounds for Proximity Report based Indoor Positioning"2017Report (Other academic)
    Abstract [en]

    This reportontains supplementary material for the paper [1].

  • 99074.
    Zhao, Yuxin
    et al.
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, Faculty of Science & Engineering.
    Fritsche, Carsten
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, Faculty of Science & Engineering.
    Gunnarsson, Fredrik
    Ericsson AB.
    Parametric Lower Bound for Nonlinear Filteringbased on Gaussian Process Regression Model2017In: 2017 20th International Conference on Information Fusion (Fusion), IEEE, 2017, p. 1-7Conference paper (Refereed)
    Abstract [en]

    Assessing the fundamental performance limitationsin Bayesian filtering can be carried out using the parametricCram´er-Rao bound (CRB). The parametric CRB puts a lowerbound on mean square error (MSE) matrix conditioned on aspecific state trajectory realization. In this work, we derive theparametric CRB for state-space models, where the measurementequation is modeled by a Gaussian process regression.These models appear, for instance in proximity report-basedpositioning, where proximity reports are obtained by hardthresholding of received signal strength (RSS) measurements, thatare modeled through Gaussian process regression. The proposedparametric CRB is evaluated on selected state trajectories andfurther compared with the positioning performance obtained bythe particle filter. The results corroborate that the positioningaccuracy achieved in this framework is close to the parametricCRB.

  • 99075.
    Zhao, Yuxin
    et al.
    Research, Ericsson AB, 39174 Stockholm, Sweden.
    Fritsche, Carsten
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, Faculty of Science & Engineering.
    Yin, Feng
    SSE, Chinese University of Hong Kong Shenzhen, Shenzhen, China.
    Gunnarsson, Fredrik
    Ericsson Research, Linköping, Sweden.
    Gustafsson, Fredrik
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, Faculty of Science & Engineering.
    Sequential Monte Carlo Methods and Theoretical Bounds for Proximity Report Based Indoor Positioning2018In: IEEE Transactions on Vehicular Technology, ISSN 0018-9545, E-ISSN 1939-9359, Vol. 67, no 6, p. 5372-5386Article in journal (Refereed)
    Abstract [en]

    The commercial interest in proximity services is increasing. Application examples include location-based information and advertisements, logistics, social networking, file sharing, etc. In this paper, we consider positioning of devices based on a time series of proximity reports from a mobile device to a network node. This corresponds to nonlinear measurements with respect to the device position in relation to the network nodes. Motion model will be needed together with the measurements to determine the position of the device. Therefore, sequential Monte Carlo methods, namely particle filtering and smoothing, are applicable for positioning. Positioning performance is evaluated in a typical office area with Bluetooth-low-energy beacons deployed for proximity detection and report, and is further compared to parametric Cramér-Rao lower bounds. Finally, the position accuracy is also evaluated with real experimental data.

  • 99076.
    Zhao, Yuxin
    et al.
    Ericsson AB, Sverige.
    Liu, Chao
    University of Sheffield, UK.
    Mihaylova, Lyudmila S.
    University of Sheffield, UK.
    Gunnarsson, Fredrik
    Ericsson AB, Sverige.
    Gaussian processes for RSS fingerprints construction in indoor localization2018In: 21st International Conference on Information Fusion (FUSION), IEEE, 2018, p. 1377-1384Conference paper (Refereed)
    Abstract [en]

    Location-based applications attract more and more attention in recent years. Examples of such applications include commercial advertisements, social networking software and patient monitoring. The received signal strength (RSS) based location fingerprinting is one of the most popular solutions for indoor localization. However, there is a big challenge in collecting and maintaining a relatively large RSS fingerprint database. In this work, we propose and compare two algorithms namely, the Gaussian process (GP) and Gaussian process with variogram, to estimate and construct the RSS fingerprints with incomplete data. The fingerprint of unknown reference points is estimated based on measurements at a limited number of surrounding locations. To validate the effectiveness of both algorithms, experiments using Bluetooth-low-energy (BLE) infrastructure have been conducted. The constructed RSS fingerprints are compared to the true measurements, and the result is analyzed. Finally, using the constructed fingerprints, the localization performance of a probabilistic fingerprinting method is evaluated.

  • 99077.
    Zhao, Yuxin
    et al.
    Ericsson Research, Linköping, Sweden.
    Yin, Feng
    Ericsson Research, Linköping, Sweden.
    Gunnarsson, Fredrik
    Ericsson Research, Linköping, Sweden.
    Amirijoo, Mehdi
    Ericsson Research, Linköping, Sweden.
    Hendeby, Gustaf
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, Faculty of Science & Engineering.
    Gaussian Process for Propagation modeling and Proximity Reports Based Indoor Positioning2016In: 2016 IEEE 83rd Vehicular Technology Conference (VTC Spring), IEEE , 2016, p. 1-5Conference paper (Refereed)
    Abstract [en]

    The commercial interest in proximity services is increasing. Application examples include location-based information and advertisements, logistics, social networking, file sharing, etc. In this paper, we consider network-based positioning based on times series of proximity reports from a mobile device, either only a proximity indicator, or a vector of RSS from observed nodes. Such positioning corresponds to a latent and nonlinear observation model. To address these problems, we combine two powerful tools, namely particle filtering and Gaussian process regression (GPR) for radio signal propagation modeling. The latter also provides some insights into the spatial correlation of the radio propagation in the considered area. Radio propagation modeling and positioning performance are evaluated in a typical office area with Bluetooth-Low-Energy (BLE) beacons deployed for proximity detection and reports. Results show that the positioning accuracy can be improved by using GPR.

  • 99078.
    Zhao, Yuxin
    et al.
    Ericsson Research, Linköping, Sweden.
    Yin, Feng
    Ericsson Research, Linköping, Sweden.
    Gunnarsson, Fredrik
    Ericsson Research, Linköping, Sweden.
    Amirijoo, Mehdi
    Ericsson Research, Linköping, Sweden.
    Özkan, Emre
    ISY, Linköping University.
    Gustafsson, Fredrik
    ISY, Linköping University.
    Particle Filtering for Positioning Based on Proximity Reports2015Conference paper (Refereed)
    Abstract [en]

    The commercial interest in proximity services is increasing. Application examples include location-based information and advertisements, logistics, social networking, file sharing, etc. In this paper, we consider positioning of devices based on time series proximity reports from a mobile device to a network node. This corresponds to nonlinear measurements with respect to the device position in relation to the network nodes. Therefore, particle filtering is applicable for positioning. Positioning performance is evaluated in a typical office area with Bluetooth-low-energy beacons deployed for proximity detection and report. Accuracy is concluded to vary spatially over the office floor, and in relation to the beacon deployment density.

  • 99079.
    Zhao, Yuxin
    et al.
    Ericsson AB, Sweden.
    Yin, Feng
    Ericsson AB, Sweden.
    Gunnarsson, Fredrik
    Ericsson AB, Sweden.
    Hultkratz, Fredrik
    Ericsson AB, Sweden.
    Fagerlind, Johan
    Ericsson AB, Sweden.
    Gaussian Processes for Flow Modeling and Prediction of Positioned Trajectories Evaluated with Sports Data2016In: 19th International Conference on  Information Fusion (FUSION), 2016, Institute of Electrical and Electronics Engineers (IEEE), 2016, p. 1461-1468Conference paper (Refereed)
    Abstract [en]

    Kernel-based machine learning methods are gaining increasing interest in flow modeling and prediction in recent years. Gaussian process (GP) is one example of such kernelbased methods, which can provide very good performance for nonlinear problems. In this work, we apply GP regression to flow modeling and prediction of athletes in ski races, but the proposed framework can be generally applied to other use cases with device trajectories of positioned data. Some specific aspects can be addressed when the data is periodic, like in sports where the event is split up over multiple laps along a specific track. Flow models of both the individual skier and a cluster of skiers are derived and analyzed. Performance has been evaluated using data from the Falun Nordic World Ski Championships 2015, in particular the Men’s cross country 4 × 10 km relay. The results show that the flow models vary spatially for different skiers and clusters. We further demonstrate that GP regression provides powerful and accurate models for flow prediction.

  • 99080.
    Zhao, Zeng-Ren
    et al.
    Hebei Med Univ, Shijiazhuang, Peoples R China.
    Zhang, Li-Jing
    Hebei Med Univ, Shijiazhuang, Peoples R China.
    He, Xin-Qi
    Hebei Med Univ, Shijiazhuang, Peoples R China.
    Zhang, Zhi-Yong
    Hebei Med Univ, Shijiazhuang, Peoples R China.
    Zhang, Feng
    Hebei Med Univ, Shijiazhuang, Peoples R China.
    Li, Fang
    Hebei Med Univ, Shijiazhuang, Peoples R China.
    Pei, Yong-Bin
    Hebei Med Univ, Shijiazhuang, Peoples R China.
    Hu, Yue-Ming
    Hebei Med Univ, Shijiazhuang, Peoples R China.
    Wang, Ming-Wei
    Hebei Med Univ, Shijiazhuang, Peoples R China.
    Sun, Xiao-Feng
    Linköping University, Department of Clinical and Experimental Medicine, Oncology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology UHL.
    Significance of mRNA and Protein Expression of MAC30 in Progression of Colorectal Cancer2011In: Chemotherapy, ISSN 0009-3157, E-ISSN 1421-9794, Vol. 57, no 5, p. 394-401Article in journal (Refereed)
    Abstract [en]

    Background: Meningioma-associated protein (MAC30), first described to be overexpressed in meningiomas, exhibits altered expression in certain human tumors. The aim of our study was to investigate the expression of MAC30 mRNA and its correlation with clinicopathological variables in human colorectal cancer (CRC). Methods: MAC30 mRNA expression was first examined in 55 CRCs, along with the samples from the matched distant normal and adjacent noncancerous tissue by RT-PCR, further verified in 18 CRCs by quantitative RT-PCR. MAC30 protein expression was detected by Western blot in 10 CRCs, and DNA sequencing was performed in 1 case of the paired CRC and the matched noncancerous specimen. MAC30 mRNA expression in two colon cancer cell lines, HCT-116(p53-/-) and HCT-116(p53+/+), was detected by quantitative RT-PCR. Results: The mRNA expression of MAC30 was increased in CRC when compared with distant normal (p < 0.01) and adjacent noncancerous mucosa (p < 0.01). The mean value of MAC30 mRNA expression in the tumor located in the colon was higher than in the rectum (0.677 +/- 0.419 vs. 0.412 +/- 0.162, p = 0.005). As the tumor penetrated the wall of the colon/rectum, MAC30 mRNA expression notably increased in tumors with T3+T4 stage compared to tumors with T1+T2 stage (0.571 +/- 0.364 vs. 0.404 +/- 0.115, p = 0.014). MAC30 protein expression in CRCs was also remarkably elevated compared to the adjacent noncancerous mucosa. There was no mutation in the coding region of the MAC30 gene either in CRC or in the noncancerous mucosa. mRNA expression of p53 was notably decreased in HCT-116(p53-/-) compared to HCT-116(p53+/+), while MAC30 did not vary greatly. Conclusion: The overexpression of MAC30 might be involved in the development and aggressiveness of CRCs, especially in the colon.

  • 99081.
    Zhao, Zeng-Ren
    et al.
    Hebei Medical University, Peoples R China Hebei Medical University, Peoples R China .
    Zhang, Li-Jing
    Hebei Medical University, Peoples R China .
    Wang, Yuan-Yuan
    Hebei Medical University, Peoples R China .
    Li, Fang
    Hebei Medical University, Peoples R China .
    Wang, Ming-Wei
    Hebei Medical University, Peoples R China .
    Sun, Xiao-Feng
    Linköping University, Department of Clinical and Experimental Medicine, Oncology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology UHL.
    Increased serum level of Nup88 protein is associated with the development of colorectal cancer2012In: Medical Oncology, ISSN 1357-0560, E-ISSN 1559-131X, Vol. 29, no 3, p. 1789-1795Article in journal (Refereed)
    Abstract [en]

    Nucleoporin88 (Nup88) has been shown to be overexpressed in a wide variety of malignancies including colorectal cancer (CRC). However, no study about serum Nup88 in human CRC was reported. Therefore, in this study, we investigated the level of serum Nup88 protein and its relationships with clinicopathological variables in CRC. The serum concentration of Nup88 protein was determined by a quantitative sandwich enzyme-linked immunosorbent assay (ELISA) in 118 pre-operative serum samples, 66 post-operative and 96 healthy controls. Among the patients, the levels of CEA (n = 91) and CA19-9 (n = 87) in the pre-operative serum were measured, and DNA sequencing was performed in 12 CRCs and 2 samples from non-cancerous colon tissue. In the same patients, the level of pre-operative serum Nup88 was significantly higher than that of post-operative Nup88 (P = 0.021). Furthermore, the level of pre-operative Nup88 was positively related to the depth of tumor invasion (P = 0.002) and advanced stage (P = 0.001). The level of pre-operative Nup88 in the left colon tended to be higher than that in the right colon and the rectum (P = 0.063). DNA sequencing results showed that there were two single nucleotide polymorphisms, distributed in exon 6 (NM_002532.3:c.1044Gandgt;A (ACG-ACA, Thr -andgt; Thr) and exon 10 (NM_002532.3: c.1389Aandgt;T, CCA-CCT, Pro -andgt; Pro). Serum Nup88 might be a candidate for a new biomarker implicated in the development and aggressiveness of CRCs.

  • 99082. Zhao, Zeng-Ren
    et al.
    Zhang, Zhi-Yong
    Cui, Dong-Sheng
    Jiang, Li
    Zhang, Hui-Jun
    Wang, Ming-Wei
    Sun, Xiao-Feng
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Biomedicine and Surgery, Oncology. Östergötlands Läns Landsting, Centre of Surgery and Oncology, Department of Oncology UHL.
    Particularly interesting new cysteine-histidine rich protein expression in colorectal adenocarcinomas2006In: World Journal of Gastroenterology, ISSN 1007-9327, E-ISSN 2219-2840, Vol. 12, no 2, p. 298-301Article in journal (Refereed)
    Abstract [en]

    Aim: To study the relationship between particularly interesting new cysteine-histidine rich protein (PINCH) expression and clinicopathological factors in Chinese colorectal cancer patients. Methods: The expression of PINCH was examined by immumohistochemistry in 141 samples of primary colorectal adenocarcinoma and 92 normal samples of colorectal mucosa. Eighty of the cases had both primary tumour and normal mucosa from the same patients. Results: PINCH was expressed in the stroma of normal mucosa and tumours. PINCH expression in tumourassociated stroma was increased compared to normal mucosa in both unmatched cases (n = 141, X2 = 85.79, df = 3, P<0.0001) and matched cases (n = 80, X2 = 45.86, df = 3, P<0.0001). Among 135 tumours with visible invasive margin, 86 (64%) showed stronger PINCH expression at the invasive margin than in the intratumoural stroma. The frequency of PINCH strong expression in mucinous and signet-ring cell carcinomas was higher (52%) compared to non-mucinous carcinomas (29%, X2= 5.13, P= 0.02). We did not find that PINCH expression was related to patient's gender, age, tumour location, tumour size, gross status, histological type, differentiation, invasion depth, lymph node status and Dukes' stage (P>0.05). Conclusion: The expression of PINCH was upregulated in colorectal cancers, and especially at the margin of tumours, and further was related to mucinous and signet-ring cell carcinomas. The results suggest that expression of PINCH may be involved in the tumourigenesis and aggressiveness of colorectal cancers. © 2006 The WJG Press. All rights reserved.

  • 99083.
    Zhao, Zeng-Ren
    et al.
    Hebei Medical University.
    Zhang, Zhi-Yong
    Tangshan Gongren Hospital.
    He, Xin-Qi
    Hebei Medical University.
    Hu, Yue-Ming
    Tangshan Gongren Hospital.
    Tian, Yan-Feng
    Hebei Medical University.
    Zhang, Li-Jing
    Hebei Medical University.
    Sun, Xiao-Feng
    Linköping University, Department of Clinical and Experimental Medicine, Oncology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology UHL.
    Nup88 mRNA overexpression in colorectal cancers and relationship with p532010In: CANCER BIOMARKERS, ISSN 1574-0153, Vol. 8, no 2, p. 73-80Article in journal (Refereed)
    Abstract [en]

    Objectives: We measured nucleoporin 88 (Nup88) mRNA expression in primary colorectal cancers to investigate its relationship with clinicopathological features and p53. Methods: The primary cancer tissues, adjacent noncancerous tissues and the proximal and distant margins of normal mucosa were collected from 73 colorectal cancer patients during surgery. Nup88 mRNA expression was measured on these fresh specimens and on colon cell lines HCT-116 (P53+/+) and HCT-116 (P53-/-) by RT-PCR while p53 mRNA and beta-actin as controls. Nup88 and p53 protein expression were then immunohistochemistrically examined in other 25 colorectal cancers specimens paraffin embedded and formalin fixed. Results: Nup88 expression was higher in primary cancer tissues than in adjacent noncancerous tissues, and in the proximal and distant margins of normal mucosa. Overexpression of Nup88 mRNA was statistically associated with TNM stage (P = 0.044), lymphatic metastasis (P = 0.022), and cancer location (P = 0.036), while not related to gender, age of patients and histological type, infiltration depth, and differentiation of cancers. The expression of Nup88 mRNA in the HCT-116 (P53-/-) cell line was not significantly different from expression in the HCT-116 (P53+/+) cell line. And there was no correlation between Nup88 and p53 protein expression (r = 0.632, P = 0.368). Conclusions: Nup88 mRNA was overexpressed in colorectal cancers and the overexpression was associated with cancer development and aggressiveness. Nup88 might be regard as essential contributor to nodal metastagenicity of colorectal cancer.

  • 99084.
    Zhao, Zeng-Ren
    et al.
    Department of General Surgery Hebei Medical University, Shijiazhuang 050031, P.R. China.
    Zhang, Zhiyong
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Oncology .
    Zhang, Hong
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Dermatology and Venerology .
    Jiang, Li
    Department of Pathology Tangshan Gongren Hospital, Tangshan 063000, P.R. China.
    Wang, Ming-Wei
    Laboratory Centre Hebei Medical University, Shijiazhuang 050031, P.R. China.
    Sun, Xiao-Feng
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Oncology . Östergötlands Läns Landsting, Centre of Surgery and Oncology, Department of Oncology UHL.
    Overexpression of Id-1 protein is a marker in colorectal cancer progression2008In: Oncology Reports, ISSN 1021-335X, E-ISSN 1791-2431, Vol. 19, no 2, p. 419-424Article in journal (Refereed)
    Abstract [en]

    The inhibitor of differentiation/DNA binding 1 (Id-1), a negative regulator of basic helix-loop-helix transcription factors, plays an important role in the regulation of cell proliferation and differentiation. We examined the Id-1 expression by immunohistochemistry in 9 adenomas, 79 primary colorectal adenocarcinomas matched with 40 adjacent normal mucosa specimens and its relationship with clinicopathological factors. The Id-1 expression was increased in the carcinoma compared to the adjacent normal mucosa either in the unmatched and matched samples or to the adenoma. There was no significant difference in the Id-1 expression between normal mucosa and adenoma. The Id-1 expression of carcinoma was increased from Dukes' stages A to B, to C and to D. The cases with lymph node metastasis had a higher rate of a stronger Id-1 expression than those without lymph node metastasis. In conclusion, Id-1 overexpression plays an important role in colorectal cancer progression.

  • 99085.
    Zhazykpayeva, Saltanat
    Linköping University, Department of Management and Engineering, Business Administration.
    The Interplay between Voluntary Labor Turnover and Performance Appraisal in Project-Based Organizations2011Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The research made in the current master thesis uses theoretical framework from the area of project management, voluntary labor turnover and performance appraisal. Prior research based on existing literary sources allows assuming that the following factors, such as job alternatives, knowledge intensity and nature of work have specific relevance for the emergence of voluntary labor turnover in project-based organizations. Employees of the case study company-AGR Field Operations´ Maintenance Engineering department were interviewed and surveyed in order to determine the relevance of those factors on the example of a concrete project-based organization. The obtained results indicate that the nature of work is more significantly related to the emergence of the voluntary labor turnover in the given case study department. Whereas availability of more job alternatives due to being close to the client or knowledge intensity factor of becoming more generalist do not have the same influence. During the course of the research it was discovered that the department uses outcome-based type of performance appraisal which is proved to be unsuitable in the given organizational settings. To that matter there were provided further suggestions in the field of performance appraisal. The current research will attempt to identify specific factors contributing to the emergence of the voluntary labor turnover specifically for project-based organizations. As well as it will attempt to give suggestions for improvement of the concrete case study department´s performance appraisal tools and thus supplement turnover reduction actions already put in place by the department management. 

  • 99086.
    Zheltukhina, Daria
    Linköping University, Department of Culture and Communication, Language and Culture.
    Rhythmicity and Broken Narrative as a Means of Portraying Identity Crisis in Erna Brodber’s Jane and Louisa Will Soon Come Home2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In the present thesis, Jane and Louisa Will Soon Come Home, the novel by the Jamaican writer Erna Brodber, is analyzed in the context of post-colonial identity trauma. Analyzing the complex organizational and narrative structure of the novel, the essay author studies how the novel’s rhythmicity and the broken narrative portray the protagonist’s identity fragmentation. Drawing on the work’s connection to the ring game played in the Caribbean and applying the symbolism of the Caribbean folk rhythms, the essay author discusses the subversive intent of Brodber’s novel and her method of rewriting the past as a way of recovering one's identity. 

  • 99087.
    Zheltukhina, Daria
    Linköping University, Department of Culture and Communication, Language and Culture. Linköping University, Faculty of Arts and Sciences.
    The Functions of Journey and Ascent in Selected Short Stories in Margaret Drabble’s A Day in the Life of a Smiling Woman2013Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The present essay studies the functions of journey and ascent as recurrent motifs in A Day in the Life of a Smiling Woman by Margaret Drabble. The relationships between the geographical and psychological journeys and ascents are explored. Chapter 2 of the core analysis presents the four themes in which the protagonists articulate their strength and self-worth. Chapter 3 is devoted to the comparative analysis of the structures of the geographical and psychological journeys and ascents (item 3.2) and the study of the author's multiple angles on marriage, adultery and widowhood (item 3.3). 

  • 99088.
    Zhen, Hongyu
    et al.
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology. 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
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Fabiano, Simone
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Gao, Feng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Solution-processed bulk-heterojunction organic solar cells employing Ir complexes as electron donors2014In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 2, no 31, p. 12390-12396Article in journal (Refereed)
    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.

  • 99089.
    Zhen, Hongyu
    et al.
    Zhejiang Univ, Peoples R China.
    Li, Kan
    Zhejiang University, Peoples R China .
    Huang, Zhuoyin
    Zhejiang University, Peoples R China .
    Tang, Zheng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Wu, Rengmao
    Zhejiang University, Peoples R China .
    Li, Guolong
    Zhejiang University, Peoples R China .
    Liu, Xu
    Zhejiang University, Peoples R China .
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Inverted indium-tin-oxide-free cone-shaped polymer solar cells for light trapping2012In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 100, no 21, p. 213901-Article in journal (Refereed)
    Abstract [en]

    Based on the flexibility of polymer film, cone-shaped polymer solar cells (PSCs) are fabricated and studied. Effective light trapping is achieved due to multi-absorption in all 360 degrees directions. Monte Carlo ray tracing is used to simulate the absorption of cone-shaped PSCs with two variables: wavelength and half cone angle. With an inverted indium-tin-oxide-free device structure, a 43% enhanced light utilization without loss of material utilization is realized in the cone-shaped PSCs with a half cone angle of 45 degrees, compared with the planar PSCs.

  • 99090.
    Zhenchuk, Anna
    et al.
    Department of Oncology-Pathology, Cancer Center Karolinska, Karolinska Institute, Karolinska Hospital, Stockholm, Sweden.
    Lotfi, Koroush
    Linköping University, Department of Medical and Health Sciences, Clinical Pharmacology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Laboratory Medicine, Department of Clinical Pharmacology.
    Juliusson, Gunnar
    Lund Strategic Center for Stem Cell Biology and Therapy, Department of Hematology, Lund University Hospital, Lund, Sweden.
    Albertioni, Freidoun
    Department of Oncology-Pathology, Cancer Center Karolinska, Karolinska Institute, Karolinska Hospital, Stockholm, Sweden.
    Commentary: Mechanisms of anti-cancer action and pharmacology of clofarabine: in BIOCHEMICAL PHARMACOLOGY, ISSN 0006-2952, vol 78, issue 11, pp 1351-13592009In: Biochemical Pharmacology, ISSN 0006-2952, E-ISSN 1356-1839, Vol. 78, no 11, p. 1351-1359Article in journal (Other academic)
    Abstract [en]

    Clofarabine, a next-generation deoxyadenosine analogue, was developed on the basis of experience with cladribine and fludarabine in order to achieve higher efficacy and avoid extramedullary toxicity. During the past decade this is the only drug granted approval for treatment of pediatric acute leukemia. Recent clinical studies have established the efficacy of clofarabine in treating malignancies with a poor prognosis, such as adult, elderly, and relapsed pediatric leukemia. The mechanisms of its anti-cancer activity involve a combination of direct inhibition of DNA synthesis and ribonucleotide reductase and induction of apoptosis. Due to this broad cytotoxicity, this drug is effective against various subtypes of leukemia and is currently being tested as an oral formulation and for combination therapy of both leukemias and solid tumors. In this review we summarize current knowledge pertaining to the molecular mechanisms of action and pharmacological properties of clofarabine, as well as clinical experiences with this drug with the purpose of facilitating the evaluation of its efficacy and the development of future therapies.

  • 99091.
    Zhendong, Wang
    Linköping University, Department of Computer and Information Science, The Division of Statistics and Machine Learning. Linköping University, Faculty of Arts and Sciences.
    Error Pattern Recognition Using Machine Learning2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Mobile networks use automated continuous integration to secure the new technologies, which must reach high quality and backwards compatibility. The machinery needs to be constantly improved to meet the high demands that exist today and will evolve in the future. When testing products in large scale in a telecommunication environment, many parameters may be causing the error. Machine learning can help to assign troubleshooting labels and identify problematic areas in the test environment.

    In this thesis project, different modeling approaches will be applied step-wise. First, both the TF-IDF (term frequency-inverse document frequency) method and Topic model- ing will be applied for constructing variables. Since the TF-IDF method generates high dimensional variables in this case, Principal component analysis (PCA) is considered as a regularization method to reduce the dimensions. The results of this part will be evaluated by using different criteria.

    After the variable construction, two semi-supervised models called Label propagation and Label spreading will be applied for the purpose of assigning troubleshooting labels. In both algorithms, one weight matrix for measuring the similarities between different cases needs to be constructed. Two different methods for building up the weight matrix will be tested separately: Gaussian kernel and the nearest-neighbor method.

    Different hyperparameters in these two algorithms will be experimented with, to select the one which will return the optimal results. After the optimal model is selected, the unlabeled data will be divided up in different proportions for fitting the model. This is to test if the proportions of unlabeled data will affect the result of semi-supervised learning in our case. The classification results from the modeling part will be examined using three classical measures: accuracy, precision and recall. In addition, random permutations cross- validation is applied for the evaluation.

  • 99092.
    Zhen-Dong, Yuan
    et al.
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, The Institute of Technology.
    Ljung, Lennart
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, The Institute of Technology.
    Optimal Input Design by Frequency Domain Criteria1982Report (Other academic)
    Abstract [en]

    Some explicit, analytical result on optimal input design for identification of transfer functions are derived. The results are asymptotic as the model order increases. This can be interpreted as a reduction of prejudice in the design; the prejudice being that the system is "known" to belong to a certain low-order model set.

  • 99093. Zheng, Bing Song
    et al.
    Rönnberg, Elin
    Viitanen, Lenita
    Salminen, Tiina A.
    Lundgren, Krister
    Moritz, Thomas
    Edqvist, Johan
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Molecular genetics .
    Arabidopsis sterol carrier protein-2 is required for normal development of seeds and seedlings2008In: Journal of Experimental Botany, ISSN 0022-0957, E-ISSN 1460-2431, Vol. 59, no 12, p. 3485-3499Article in journal (Refereed)
    Abstract [en]

    The Arabidopsis thaliana sterol carrier protein-2 (AtSCP2) is a small, basic and peroxisomal protein that in vitro enhances the transfer of lipids between membranes. AtSCP2 and all other plant SCP-2 that have been identified are single-domain polypeptides, whereas in many other eukaryotes SCP-2 domains are expressed in the terminus of multidomain polypeptides. The AtSCP2 transcript is expressed in all analysed tissues and developmental stages, with the highest levels in floral tissues and in maturing seeds. The expression of AtSCP2 is highly correlated with the multifunctional protein-2 (MFP2) involved in β-oxidation. A. thaliana Atscp2-1 plants deficient in AtSCP2 show altered seed morphology, a delayed germination, and are dependent on an exogenous carbon source to avoid a delayed seedling establishment. Metabolomic investigations revealed 110 variables (putative metabolites) that differed in relative concentration between Atscp2-1 and normal A. thaliana wild-type seedlings. Microarray analysis revealed that many genes whose expression is altered in mutants with a deficiency in the glyoxylate pathway, also have a changed expression level in Atscp2-1. © 2008 The Author(s).

  • 99094. Zheng, Jiefu
    et al.
    Ramamoorthy, Sripriya
    Ren, Tianying
    He, Wenxuan
    Zha, Dingjun
    Chen, Fangyi
    Magnusson, Anna
    Nuttall, Alfred L
    Fridberger, Anders
    Karolinska Institutet, Stockholm, Sweden.
    Persistence of past stimulations: storing sounds within the inner ear2011In: Biophysical Journal, ISSN 0006-3495, E-ISSN 1542-0086, Vol. 100, no 7, p. 1627-1634Article in journal (Refereed)
    Abstract [en]

    Tones cause vibrations within the hearing organ. Conventionally, these vibrations are thought to reflect the input and therefore end with the stimulus. However, previous recordings of otoacoustic emissions and cochlear microphonic potentials suggest that the organ of Corti does continue to move after the end of a tone. These after-vibrations are characterized here through recordings of basilar membrane motion and hair cell extracellular receptor potentials in living anesthetized guinea pigs. We show that after-vibrations depend on the level and frequency of the stimulus, as well as on the sensitivity of the ear. Even a minor loss of hearing sensitivity caused a sharp reduction in after-vibration amplitude and duration. Mathematical models suggest that after-vibrations are driven by energy added into organ of Corti motion after the end of an acoustic stimulus. The possible importance of after-vibrations for psychophysical phenomena such as forward masking and gap detection are discussed.

  • 99095.
    Zheng, Kaibo
    et al.
    Lund University, Sweden .
    Zidek, Karel
    Lund University, Sweden .
    Abdellah, Mohamed
    Lund University, Sweden .
    Torbjornsson, Magne
    Lund University, Sweden .
    Chabera, Pavel
    Lund University, Sweden .
    Shao, Shuyan
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Pullerits, Tonu
    Lund University, Sweden .
    Fast Monolayer Adsorption and Slow Energy Transfer in CdSe Quantum Dot Sensitized ZnO Nanowires2013In: Journal of Physical Chemistry A, ISSN 1089-5639, E-ISSN 1520-5215, Vol. 117, no 29, p. 5919-5925Article in journal (Refereed)
    Abstract [en]

    A method for CdSe quantum dot (QD) sensitization of ZnO nanowires (NW) with fast adsorption rate is applied. Photoinduced excited state dynamics of the quantum dots in the case of more than monolayer coverage of the nanowires is studied. Transient absorption kinetics reveals an excitation depopulation process of indirectly attached quantum dots with a lifetime of similar to 4 ns. Photoluminescence and incident photon-to-electron conversion efficiency show that this process consists of both radiative e-h recombination and nonradiative excitation-to-charge conversion. We argue that the latter occurs via interdot energy transfer from the indirectly attached QDs to the dots with direct contact to the nanowires. From the latter, fast electron injection into ZnO occurs. The energy transfer time constant is found to be around 5 ns.

  • 99096.
    Zheng, Limin
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology .
    Forsberg, Maria
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Molecular and Clinical Medicine.
    Stendahl, Olle
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology .
    Invasive Salmonella typhimurium induces apoptosis in human U937 cells by activating Rho GTPases2000In: Molecular Biology of the Cell, ISSN 1059-1524, E-ISSN 1939-4586, Vol. 11, p. 1527-Conference paper (Other academic)
  • 99097.
    Zheng, Limin
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    He, Min
    Department of Biochemistry, College of Life Sciences, Sun Yatsen (Zhongshan) University, Guangzhou, China.
    Long, Min
    Blomgran, Robert
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Stendahl, Olle
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Pathogen-Induced Apoptotic Neutrophils Express Heat Shock Proteins and Elicit Activation of Human Macrophages2004In: Journal of immunology, ISSN 0022-1767, Vol. 173, no 10, p. 6319-6326Article in journal (Refereed)
    Abstract [en]

    Ingestion of aged or irradiated apoptotic neutrophils actively suppresses stimulation of macrophages (MΦ). Many bacterial pathogens can also provoke apoptosis in neutrophils, but little is known about how such apoptotic cells influence MΦ activation. We found that neutrophils undergoing apoptosis induced by UV irradiation, Escherichia coli, or Staphylococcus aureus could either stimulate or inhibit MΦ activation. In contrast to MΦ that had ingested irradiated apoptotic neutrophils, MΦ that had phagocytosed bacteria-induced apoptotic neutrophils exhibited markedly increased production of the proinflammatory cytokine TNF-α, but not the anti-inflammatory cytokine TGF-β. Moreover, ingestion of bacteria, but not UV-induced apoptotic neutrophils, caused increased expression of FcγRI on MΦ, and this effect was not provoked directly by bacteria associated with the apoptotic neutrophils. Instead, we found that a link between pathogen-induced apoptotic neutrophils and up-regulation of the heat shock proteins HSP60 and HSP70, and we also observed that recombinant HSP60 and HSP70 potentiated LPS-stimulated production of TNF-α in MΦ. The opposing macrophage responses to neutrophils undergoing apoptosis induced in different ways may represent a novel mechanism that regulates the extent of the immune response to invading microbes in two steps: first by aiding the functions of MΦ at an early stage of infection, and subsequently by deactivating those cells through removal of uninfected apoptotic neutrophils. HSP induction in neutrophils may provide the danger signals required to generate a more effective macrophage response.

  • 99098.
    Zheng, Lin
    Linköping University, Department of Clinical and Experimental Medicine, Geriatric. Linköping University, Faculty of Health Sciences.
    Lysosomal Involvement in the Pathogenesis of Alzheimer's Disease2012Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Alzheimer’s disease (AD), the major cause of senile dementia, is associated with progressive formation of neurofibrillary tangles and extraneuronal plaques composed of amyloid beta peptide (Aβ). Aβ has been also found within Alzheimer neurons in association with the lysosomal system, an acidic vacuolar compartment possessing numerous hydrolytic enzymes. Lysosomes have been shown to be involved in both the formation of Aβ and its toxicity to neurons. Another line of evidence implicates oxidative stress as an important factor in the development of AD. It is reported that oxidative damage is one of the earliest changes in AD and plays an important role in the development of the disease. Although both the lysosomal system and reactive oxygen species are involved in AD, the mechanisms of this involvement are not well understood.

    To gain insight into the relationship between oxidative stress and the lysosomal system in AD pathogenesis, we focused our study on: 1) The effect of oxidative stress on intracellular distribution of Aβ; 2) the role of endogenous Aβ in oxidant-induced apoptosis; 3) the role of autophagy and APP processing in oxidant induced damage; and, 4) the intraneuronal localization of Aβ and its relationship to the lysosomal system.

    In our study, hyperoxia (40% versus 8% ambient oxygen) was used as a model of mild oxidative stress in vitro, while transfected cells producing different amounts of Aβ were used to assess toxicity due to endogenous Aβ. It was found that: 1) oxidative stress induces autophagic uptake of Aβ, resulting in its partial accumulation within lysosomes; 2) oxidative stress can induce neuronal death through macroautophagy of Aβ and consequent lysosomal membrane permeabilization; 3) increased cellular Aβ production is associated with enhanced oxidative stress and enhanced macroautophagy, resulting in increased intralysosomal Aβ accumulation and consequent apoptosis; and, 4) in normal conditions, intracellular Aβ shows primarily cytosolic distribution, not related to lysosomes and other acidic vacuoles, endoplasmic reticulum, Golgi complexes, synaptic vesicles or mitochondria. Only a minor portion of Aβ shows partial colocalization with cellular organelles. Inhibition of secretion significantly increased Aβ colocalization with endoplasmic reticulum, Golgi complexes, synaptic vesicles and lysosomes, as well as the amount of mitochondrial and cytosolic Aβ.

    Oxidative stress induces intralysosomal autophagy-generated Aβ accumulation, consequently causing lysosomal membrane permeabilization and apoptosis. Our findings provide a possible explanation of the interactive role of oxidative stress and lysosomal system in AD pathogenesis, and may be helpful for a future therapeutic strategy against AD.

    List of papers
    1. Autophagy of amyloid beta-protein in differentiated neuroblastoma cells exposed to oxidative stress
    Open this publication in new window or tab >>Autophagy of amyloid beta-protein in differentiated neuroblastoma cells exposed to oxidative stress
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    2006 (English)In: Neuroscience Letters, ISSN 0304-3940, E-ISSN 1872-7972, Vol. 394, no 3, p. 184-189Article in journal (Refereed) Published
    Abstract [en]

    Oxidative stress is considered important for the pathogenesis of Alzheimer disease (AD), which is characterized by the formation of senile plaques rich in amyloid beta-protein (Aβ). Aβ cytotoxicity has been found dependent on lysosomes, which are abundant in AD neurons and are shown to partially co-localize with Aβ. To determine whether oxidative stress has any influence on the relationship between lysosomes and Aβ1-42 (the most toxic form of Aβ), we studied the effect of hyperoxia (40% versus 8% ambient oxygen) on the intracellular localization of Aβ1-42 (assessed by immunocytochemistry) in retinoic acid differentiated SH-SY5Y neuroblastoma cells maintained in serum-free OptiMEM medium. In control cells, Aβ1-42 was mainly localized to small non-lysosomal cytoplasmic granules. Only occasionally Aβ1-42 was found in large (over 1 μm) lysosomal-associated membrane protein 2 positive vacuoles, devoid of the early endosomal marker rab5. These large Aβ1-42-containing lysosomes were not detectable in the presence of serum (known to suppress autophagy), while their number increased dramatically (up to 24-fold) after exposure of cells to hyperoxia during 5 days. Activation of autophagy by hyperoxia was confirmed by transmission electron microscopy. Furthermore, an inhibitor of autophagic sequestration 3-methyladenine prevented the accumulation of Aβ1-42-positive lysosomes due to hyperoxia. In parallel experiments, intralysosomal accumulation of Aβ1-40 following oxidative stress has been found as well. The results suggest that Aβ can be autophagocytosed and its accumulation within neuronal lysosomes is enhanced by oxidative stress. © 2005 Elsevier Ireland Ltd. All rights reserved.

    Keywords
    Alzheimer disease; Amyloid beta-protein; Autophagy; Lysosomes; Reactive oxygen species
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-35894 (URN)10.1016/j.neulet.2005.10.035 (DOI)28972 (Local ID)28972 (Archive number)28972 (OAI)
    Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2017-12-13Bibliographically approved
    2. Oxidative stress induces macroautophagy of amyloid beta-protein and ensuing apoptosis
    Open this publication in new window or tab >>Oxidative stress induces macroautophagy of amyloid beta-protein and ensuing apoptosis
    Show others...
    2009 (English)In: Free Radical Biology & Medicine, ISSN 0891-5849, E-ISSN 1873-4596, Vol. 46, no 3, p. 422-429Article in journal (Refereed) Published
    Abstract [en]

    There is increasing evidence for the toxicity of intracellular amyloid beta-protein (A beta) to neurons and the involvement of lysosomes in this process in Alzheimer disease (AD). We have recently shown that oxidative stress, a recognized determinant of AD. enhances macroautophagy and leads to intralysosomal accumulation of A beta in Cultured neuroblastoma cells. We hypothesized that oxidative stress promotes AD by stimulating macroautophagy of A that further may induce cell death by destabilizing lysosomal membranes. To investigate such possibility, we compared the effects of hyperoxia (40% ambient oxygen) in cultured HEK293 cells that were transfected with an empty vector (Vector), wild-type APP (APPwt), or Swedish mutant APP (APPswe). Exposure to hyperoxia for 5 days increased the number of cells with A beta-containing lysosomes, as well as the number of apoptotic cells, compared to normoxic conditions. The rate of apoptosis in all three cell lines demonstrated dependence on intralysosomal A beta content (Vector<APPwt<APPswe). Furthermore, the degree of apoptosis was positively correlated with lysosomal membrane permeabilization, whereas inhibitors Of macroautophagy and lysosomal function decreased oxidant-induced apoptosis and diminished the differences in apoptotic response between different cell lines. These results suggest that oxidative stress can induce neuronal death through macroautophagy of A beta and consequent lysosomal membrane permeabilization, which may help explain the mechanisms behind neuronal loss in AD.

    Keywords
    Alzheimer disease, Amyloid beta-protein, Amyloid precursor protein, Apoptosis, Autophagy, Lysosomes, Oxidative stress, Free radicals
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-16625 (URN)10.1016/j.freeradbiomed.2008.10.043 (DOI)
    Available from: 2009-02-08 Created: 2009-02-06 Last updated: 2017-12-14Bibliographically approved
    3. Macroautophagy-generated increase of lysosomal amyloid β-protein mediates oxidant-induced apoptosis of cultured neuroblastoma cells
    Open this publication in new window or tab >>Macroautophagy-generated increase of lysosomal amyloid β-protein mediates oxidant-induced apoptosis of cultured neuroblastoma cells
    Show others...
    2011 (English)In: Autophagy, ISSN 1554-8627, E-ISSN 1554-8635, Vol. 7, no 12, p. 1528-1545Article in journal (Refereed) Published
    Abstract [en]

    Increasing evidence suggests the toxicity of intracellular amyloid β-protein (Aβ) to neurons, as well as the involvement of oxidative stress in Alzheimer disease (AD). Here we show that normobaric hyperoxia (exposure of cells to 40% oxygen for five days, and consequent activation of macroautophagy and accumulation of Aβ within lysosomes, induced apoptosis in differentiated SH-SY5Y neuroblastoma cells. Cells under hyperoxia showed: (1) increased numbers of autophagic vacuoles that contained amyloid precursor protein (APP) as well as Aβ monomers and oligomers, (2) increased reactive oxygen species production, and (3) enhanced apoptosis. Oxidant-induced apoptosis positively correlated with cellular Aβ production, being the highest in cells that were stably transfected with APP Swedish KM670/671NL double mutation. Inhibition of γ-secretase, prior and/or in parallel to hyperoxia, suggested that the increase of lysosomal Aβ resulted mainly from its autophagic uptake, but also from APP processing within autophagic vacuoles. The oxidative stress-mediated effects were prevented by macroautophagy inhibition using 3-methyladenine or ATG5 downregulation. Our results suggest that upregulation of macroautophagy and resulting lysosomal Aβ accumulation are essential for oxidant-induced apoptosis in cultured neuroblastoma cells and provide aditional support for the interactive role of oxidative stress and the lysosomal system in AD-related neurodegeneration.

    Place, publisher, year, edition, pages
    Landes Bioscience, 2011
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-72778 (URN)10.4161/auto.7.12.18051 (DOI)000298182600012 ()
    Note
    Funding agencies|Gustav V and Queen Victoria Foundation||County Council of Ostergotland||Stiftelsen Olle Engkvist Byggmastare||Stifielsen for Gamla Tjanarinnor||Gunoch Bertil Stohnes Stiftelse||Lions forskningsfond||Svenska Lundbeckstiftelsen||Karolinska Institute Fund for Geriatric Research||Alice och Knut Wallenberg Stiftelse||Swedish Alzheimer Foundation||Swedish Brain Power||Available from: 2011-12-07 Created: 2011-12-07 Last updated: 2017-12-08Bibliographically approved
    4. Intracellular localization of amyloid beta peptide in SH-SY5Y neuroblastoma cells
    Open this publication in new window or tab >>Intracellular localization of amyloid beta peptide in SH-SY5Y neuroblastoma cells
    Show others...
    2013 (English)In: Journal of Alzheimer's Disease, ISSN 1387-2877, E-ISSN 1875-8908, Vol. 37, no 4, p. 713-733Article in journal (Refereed) Published
    Abstract [en]

    Amyloid-beta peptide (A beta), the main component of Alzheimer's disease (AD) senile plaques, has been found to accumulate within the lysosomal compartment of AD neurons. We have previously shown that in differentiated SH-SY5Y neuroblastoma cells cultured under normal conditions, the majority of A beta is localized extralysosomally, while oxidative stress significantly increases intralysosomal A beta content through activation of macroautophagy. It is, however, not clear which cellular compartments contain extralysosomal A beta in intact SH-SY5Y cells, and how oxidative stress influences the distribution of extralysosomal A beta. Using confocal laser scanning microscopy and immunoelectron microscopy, we showed that in differentiated neuroblastoma cells cultured under normal conditions A beta (A beta(40), A beta(42), and A beta oligomers) is colocalized with both membrane-bound organelles (endoplasmic reticulum, Golgi complexes, multivesicular bodies/late endosomes, lysosomes, exocytotic vesicles and mitochondria) and non-membrane-bound cytosolic structures. Neuroblastoma cells stably transfected with A beta PP Swedish KM670/671NL double mutation showed enlarged amount of A beta colocalized with membrane compartments. Suppression of exocytosis by 5 nM tetanus toxin resulted in a significant increase of the amount of cytosolic A beta as well as A beta colocalized with exocytotic vesicles, endoplasmic reticulum, Golgi complexes, and lysosomes. Hyperoxia increased A beta localization in the endoplasmic reticulum, Golgi apparatus, mitochondria, and lysosomes, but not in the secretory vesicles. These results indicate that in SH-SY5Y neuroblastoma cells intracellular A beta is not preferentially localized to any particular organelle and, to a large extent, is secreted from the cells. Challenging cells to hyperoxia, exocytosis inhibition, or A beta overproduction increased intracellular A beta levels but did not dramatically changed its localization pattern.

    Place, publisher, year, edition, pages
    IOS Press, 2013
    Keywords
    Alzheimer’s disease, Amyloid β-protein, Endosomes, Exocytosis, Lysosomes
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-73411 (URN)10.3233/JAD-122455 (DOI)000325649500007 ()
    Available from: 2012-01-03 Created: 2012-01-03 Last updated: 2017-12-08Bibliographically approved
  • 99099.
    Zheng, Lin
    et al.
    Karolinska Inst, NVS, KI Alzheimers Dis Res Ctr, S-14186 Stockholm, Sweden.
    Cedazo-Minguez, Angel
    KI-AlzheimerDisease Research Center, NVS, Novum, Karolinska Institutet, SE-141 57, Stockholm,Sweden.
    Hallbeck, Martin
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Diagnostics, Department of Clinical Pathology and Clinical Genetics.
    Jerhammar, Fredrik
    Linköping University, Department of Clinical and Experimental Medicine, Oto-Rhiono-Laryngology and Head & Neck Surgery. Linköping University, Faculty of Health Sciences.
    Hultenby, Kjell
    Clinical Research Center, Department of Laboratory Medicine, Karolinska Institutet, SE-141 86 Stockholm, Sweden.
    Marcusson, Jan
    Linköping University, Department of Clinical and Experimental Medicine, Geriatric. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Local Health Care Services in Central Östergötland, Department of Geriatric Medicine in Linköping.
    Terman, Alexi
    Department of Clinical Pathology and Cytology, Karolinska University Hospital, Huddinge, SE-141 86 Stockholm, Sweden.
    Intracellular localization of amyloid beta peptide in SH-SY5Y neuroblastoma cells2013In: Journal of Alzheimer's Disease, ISSN 1387-2877, E-ISSN 1875-8908, Vol. 37, no 4, p. 713-733Article in journal (Refereed)
    Abstract [en]

    Amyloid-beta peptide (A beta), the main component of Alzheimer's disease (AD) senile plaques, has been found to accumulate within the lysosomal compartment of AD neurons. We have previously shown that in differentiated SH-SY5Y neuroblastoma cells cultured under normal conditions, the majority of A beta is localized extralysosomally, while oxidative stress significantly increases intralysosomal A beta content through activation of macroautophagy. It is, however, not clear which cellular compartments contain extralysosomal A beta in intact SH-SY5Y cells, and how oxidative stress influences the distribution of extralysosomal A beta. Using confocal laser scanning microscopy and immunoelectron microscopy, we showed that in differentiated neuroblastoma cells cultured under normal conditions A beta (A beta(40), A beta(42), and A beta oligomers) is colocalized with both membrane-bound organelles (endoplasmic reticulum, Golgi complexes, multivesicular bodies/late endosomes, lysosomes, exocytotic vesicles and mitochondria) and non-membrane-bound cytosolic structures. Neuroblastoma cells stably transfected with A beta PP Swedish KM670/671NL double mutation showed enlarged amount of A beta colocalized with membrane compartments. Suppression of exocytosis by 5 nM tetanus toxin resulted in a significant increase of the amount of cytosolic A beta as well as A beta colocalized with exocytotic vesicles, endoplasmic reticulum, Golgi complexes, and lysosomes. Hyperoxia increased A beta localization in the endoplasmic reticulum, Golgi apparatus, mitochondria, and lysosomes, but not in the secretory vesicles. These results indicate that in SH-SY5Y neuroblastoma cells intracellular A beta is not preferentially localized to any particular organelle and, to a large extent, is secreted from the cells. Challenging cells to hyperoxia, exocytosis inhibition, or A beta overproduction increased intracellular A beta levels but did not dramatically changed its localization pattern.

  • 99100.
    Zheng, Lin
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Geriatric.
    Cedazo-Minguez, Angel
    KI-AlzheimerDisease Research Center, NVS, Novum, Karolinska Institutet, Stockholm, Sweden.
    Hallbeck, Martin
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Diagnostics, Department of Clinical Pathology and Clinical Genetics.
    Jerhammar, Fredrik
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Marcusson, Jan
    Linköping University, Department of Clinical and Experimental Medicine, Geriatric. Linköping University, Faculty of Health Sciences.
    Terman, Alexei
    Department of Clinical Pathology and Cytology, Karolinska University Hospital, Stockholm, Sweden.
    Intracellular distribution of amyloid beta peptide and its relationship to the lysosomal system.2012In: Translational Neurodegeneration, ISSN 2047-9158, Vol. 1, no 1, p. 19-Article in journal (Refereed)
    Abstract [en]

    Background

    Amyloid beta peptide (Aβ) is the main component of extraneuronal senile plaques typical of Alzheimer’s disease (AD) brains. Although Aβ is produced by normal neurons, it is shown to accumulate in large amounts within neuronal lysosomes in AD. We have recently shown that under normal conditions the majority of Aβ is localized extralysosomally, while oxidative stress significantly increases intralysosomal Aβ content through activation of macroautophagy. It is also suggested that impaired Aβ secretion and resulting intraneuronal increase of Aβ can contribute to AD pathology. However, it is not clear how Aβ is distributed inside normal neurons, and how this distribution is effected when Aβ secretion is inhibited.

    Methods

    Using retinoic acid differentiated neuroblastoma cells and neonatal rat cortical neurons, we studied intracellular distribution of Aβ by double immunofluorescence microscopy for Aβ40 or Aβ42 and different organelle markers. In addition, we analysed the effect of tetanus toxin-induced exocytosis inhibition on the intracellular distribution of Aβ.

    Results

    Under normal conditions, Aβ was found in the small cytoplasmic granules in both neurites and perikarya. Only minor portion of Aβ was colocalized with trans-Golgi network, Golgi-derived vesicles, early and late endosomes, lysosomes, and synaptic vesicles, while the majority of Aβ granules were not colocalized with any of these structures. Furthermore, treatment of cells with tetanus toxin significantly increased the amount of intracellular Aβ in both perikarya and neurites. Finally, we found that tetanus toxin increased the levels of intralysosomal Aβ although the majority of Aβ still remained extralysosomally.

    Conclusion

    Our results indicate that most Aβ is not localized to Golgi-related structures, endosomes, lysosomes secretory vesicles or other organelles, while the suppression of Aβ secretion increases intracellular intra- and extralysosomal Aβ.

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