liu.seSearch for publications in DiVA
Change search
Refine search result
1 - 5 of 5
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Burggren, Warren
    et al.
    Univ North Texas, TX USA.
    Fahlman, Andreas
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering. Fdn Oceanog, Spain; Kolmarden Wildlife Pk, Sweden; Fdn Oceanog, Spain.
    Milsom, William
    Univ British Columbia, Canada.
    Breathing patterns and associated cardiovascular changes in intermittently breathing animals: (Partially) correcting a semantic quagmire2024In: Experimental Physiology, ISSN 0958-0670, E-ISSN 1469-445XArticle, review/survey (Refereed)
    Abstract [en]

    Many animal species do not breathe in a continuous, rhythmic fashion, but rather display a variety of breathing patterns characterized by prolonged periods between breaths (inter-breath intervals), during which the heart continues to beat. Examples of intermittent breathing abound across the animal kingdom, from crustaceans to cetaceans. With respect to human physiology, intermittent breathing-also termed 'periodic' or 'episodic' breathing-is associated with a variety of pathologies. Cardiovascular phenomena associated with intermittent breathing in diving species have been termed 'diving bradycardia', 'submersion bradycardia', 'immersion bradycardia', 'ventilation tachycardia', 'respiratory sinus arrhythmia' and so forth. An examination across the literature of terminology applied to these physiological phenomena indicates, unfortunately, no attempt at standardization. This might be viewed as an esoteric semantic problem except for the fact that many of the terms variously used by different authors carry with them implicit or explicit suggestions of underlying physiological mechanisms and even human-associated pathologies. In this article, we review several phenomena associated with diving and intermittent breathing, indicate the semantic issues arising from the use of each term, and make recommendations for best practice when applying specific terms to particular cardiorespiratory patterns. Ultimately, we emphasize that the biology-not the semantics-is what is important, but also stress that confusion surrounding underlying mechanisms can be avoided by more careful attention to terms describing physiological changes during intermittent breathing and diving. What is the topic of this review? This review examines the rather confusing semantics that has been used to describe patterns in the field of cardiorespiratory physiology as it applies to intermittent breathing, particularly in diving species. What advances does it highlight? This review highlights the various cardiorespiratory phenomena associated with intermittent breathing and diving. It highlights the semantic issues associated with describing each and offers a rationale for standardizing terms based on underlying mechanisms to reduce confusion and advance the study of cardiorespiratory phenomena in both medical and comparative physiological investigations.

  • 2.
    Fahlman, Andreas
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering. Global Diving Res SL, Spain; Fdn Oceanog Comunidad Valenciana, Spain; Kolmarden Wildlife Pk, Sweden.
    Cardiorespiratory adaptations in small cetaceans and marine mammals2023In: Experimental Physiology, ISSN 0958-0670, E-ISSN 1469-445XArticle, review/survey (Refereed)
    Abstract [en]

    The dive response, or the master switch of life, is probably the most studied physiological trait in marine mammals and is thought to conserve the available O-2 for the heart and brain. Although generally thought to be an autonomic reflex, several studies indicate that the cardiovascular changes during diving are anticipatory and can be conditioned. The respiratory adaptations, where the aquatic breathing pattern resembles intermittent breathing in land mammals, with expiratory flow exceeding 160 litres s(-1) has been measured in cetaceans, and where exposure to extreme pressures results in alveolar collapse (atelectasis) and recruitment upon ascent. Cardiorespiratory coupling, where breathing results in changes in heart rate, has been proposed to improve gas exchange. Cardiorespiratory coupling has also been reported in marine mammals, and in the bottlenose dolphin, where it alters both heart rate and stroke volume. When accounting for this respiratory dependence on cardiac function, several studies have reported an absence of a diving-related bradycardia except during dives that exceed the duration that is fuelled by aerobic metabolism. This review summarizes what is known about the respiratory physiology in marine mammals, with a special focus on cetaceans. The cardiorespiratory coupling is reviewed, and the selective gas exchange hypothesis is summarized, which provides a testable mechanism for how breath-hold diving vertebrates may actively prevent uptake of N-2 during routine dives, and how stress results in failure of this mechanism, which results in diving-related gas emboli.

  • 3.
    Fahlman, Andreas
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering. Global Diving Res SL, Spain; Fdn Oceanograf Comun Valenciana, Spain; Kolmarden Wildlife Pk, Sweden; Global Diving Res SL, Spain.
    Rhieu, Kaylee
    Clearwater Marine Aquarium, FL USA.
    Alessi, Brie
    Clearwater Marine Aquarium, FL USA.
    Marquardt, Shelly
    Clearwater Marine Aquarium, FL USA.
    Schisa, Michelle B.
    Gulf World, FL USA.
    Sanchez-Contreras, Guillermo J.
    Dolphin Co, Mexico.
    Larsson, Josefin
    Kolmarden Wildlife Pk, Sweden.
    Resting metabolic rate and lung function in fasted and fed rough-toothed dolphins, Steno bredanensis2024In: Marine mammal science, ISSN 0824-0469, E-ISSN 1748-7692, Vol. 40, no 1, p. 210-221Article in journal (Refereed)
    Abstract [en]

    We measured resting metabolic rate (RMR), tidal volume (V-T), breathing frequency (f(R)), respiratory flow, and endexpired gases in rough-toothed dolphins (Steno bredanensis) housed in managed care after an overnight fast and 1-2 hr following a meal. The measured average (+/- standard deviation) V-T (4.0 +/- 1.3 L) and f(R) (1.9 +/- 1.0 breaths/min) were higher and lower, respectively, as compared with estimated values from both terrestrial and aquatic mammals, and the average V-T was 43% of the estimated total lung capacity. The end-expired gas levels suggested that this species keep alveolar O-2 (10.6% or 80 mmHg) and CO2 (7.6% or 57 mmHg), and likely arterial gas tensions, low and high, respectively, to maximize efficiency of gas exchange. We show that following an overnight fast, the RMR (566 +/- 158 ml O-2/min) was 1.8 times the estimated value predicted by Kleiber for terrestrial mammals of the same size. We also show that between 1 and 2 hr after ingestion of a meal, the metabolic rate increases an average of 29% (709 +/- 126 ml O-2/min). Both body mass (M-b) and f(R) significantly altered the measured RMR and we propose that both these variables should be measured when estimating energy use in cetaceans.

    Download full text (pdf)
    fulltext
  • 4.
    Fahlman, Andreas
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering. Fdn Oceanograf Comunitat Valenciana, Spain; Kolmarden Wildlife Pk, Sweden; Fdn Oceanograf Comunitat Valenciana, Spain.
    Tyson Moore, Reny B.
    Mote Marine Lab, FL USA.
    Stone, Rae
    Natl Museum Bermuda, Bermuda.
    Sweeney, Jay
    Natl Museum Bermuda, Bermuda.
    Trainor, Robyn Faulkner
    Natl Museum Bermuda, Bermuda.
    Barleycorn, Aaron A.
    Mote Marine Lab, FL USA.
    McHugh, Katherine
    Mote Marine Lab, FL USA.
    Allen, Jason B.
    Mote Marine Lab, FL USA.
    Wells, Randall S.
    Mote Marine Lab, FL USA.
    Deep diving by offshore bottlenose dolphins (Tursiops spp.)2023In: Marine mammal science, ISSN 0824-0469, E-ISSN 1748-7692, Vol. 39, no 4, p. 1251-1266Article in journal (Refereed)
    Abstract [en]

    We used satellite-linked tags to evaluate dive behavior in offshore bottlenose dolphins (Tursiops spp.) near the island of Bermuda. The data provide evidence that bottlenose dolphins commonly perform both long (>272 s) and deep (>199 m) dives, with the deepest and longest dives being to 1,000 m and 826 s (13.8 min), respectively. The data show a relationship between dive duration and dive depth for dives longer than about 272 s. There was a diurnal pattern to dive behavior, with most dives deeper than 50 m being performed at night; deep diving began at sunset and varied throughout the night. We used the cumulative frequency of dive duration to estimate a behavioral aerobic dive limit (bADL) of around 560-666 s (9.3-11.1 min) in adult dolphins in this population. Dives exceeding the bADL spent significantly longer time in the upper-most 50 m following a dive as compared with dives less than the bADL. We conclude that the offshore ecotype off Bermuda, unlike the shallow-diving near-shore bottlenose dolphin, is a deep-diving ecotype, and may provide a useful animal model to study extreme diving behavior and adaptations.

    Download full text (pdf)
    fulltext
  • 5.
    He, Rebecca S. S.
    et al.
    Duke Univ, NC USA.
    De Ruiter, Stacy
    Calvin Univ, MI USA.
    Westover, Tristan
    Duke Univ, NC USA.
    Somarelli, Jason A.
    Duke Univ, NC USA.
    Blawas, Ashley M.
    Duke Univ, NC USA.
    Dayanidhi, Divya L.
    Duke Univ, NC USA.
    Singh, Ana
    Calvin Univ, MI USA.
    Steves, Benjamin
    Calvin Univ, MI USA.
    Driesinga, Samantha
    Calvin Univ, MI USA.
    Halsey, Lewis G.
    Univ Roehampton, England.
    Fahlman, Andreas
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering. Fdn Oceanog Comunitat Valenciana, Spain; Kolmarden Wildlife Pk, Sweden.
    Allometric scaling of metabolic rate and cardiorespiratory variables in aquatic and terrestrial mammals2023In: Physiological Reports, E-ISSN 2051-817X, Vol. 11, no 11, article id e15698Article in journal (Refereed)
    Abstract [en]

    While basal metabolic rate (BMR) scales proportionally with body mass (M-b), it remains unclear whether the relationship differs between mammals from aquatic and terrestrial habitats. We hypothesized that differences in BMR allometry would be reflected in similar differences in scaling of O-2 delivery pathways through the cardiorespiratory system. We performed a comparative analysis of BMR across 63 mammalian species (20 aquatic, 43 terrestrial) with a M-b range from 10 kg to 5318 kg. Our results revealed elevated BMRs in small (>10 kg and <100 kg) aquatic mammals compared to small terrestrial mammals. The results demonstrated that minute ventilation, that is, tidal volume (V-T)center dot breathing frequency (f(R)), as well as cardiac output, that is, stroke volume center dot heart rate, do not differ between the two habitats. We found that the "aquatic breathing strategy", characterized by higher V-T and lower f(R) resulting in a more effective gas exchange, and by elevated blood hemoglobin concentrations resulting in a higher volume of O-2 for the same volume of blood, supported elevated metabolic requirements in aquatic mammals. The results from this study provide a possible explanation of how differences in gas exchange may serve energy demands in aquatic versus terrestrial mammals.

    Download full text (pdf)
    fulltext
1 - 5 of 5
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf