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Статті в журналах з теми "Sharks Physiology":

1

Leigh, Samantha C., Yannis Papastamatiou, and Donovan P. German. "The nutritional physiology of sharks." Reviews in Fish Biology and Fisheries 27, no. 3 (May 2017): 561–85. http://dx.doi.org/10.1007/s11160-017-9481-2.

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2

Whitney, Nicholas M., Karissa O. Lear, John J. Morris, Robert E. Hueter, John K. Carlson, and Heather M. Marshall. "Connecting post-release mortality to the physiological stress response of large coastal sharks in a commercial longline fishery." PLOS ONE 16, no. 9 (September 2021): e0255673. http://dx.doi.org/10.1371/journal.pone.0255673.

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Bycatch mortality is a major factor contributing to shark population declines. Post-release mortality (PRM) is particularly difficult to quantify, limiting the accuracy of stock assessments. We paired blood-stress physiology with animal-borne accelerometers to quantify PRM rates of sharks caught in a commercial bottom longline fishery. Blood was sampled from the same individuals that were tagged, providing direct correlation between stress physiology and animal fate for sandbar (Carcharhinus plumbeus, N = 130), blacktip (C. limbatus, N = 105), tiger (Galeocerdo cuvier, N = 52), spinner (C. brevipinna, N = 14), and bull sharks (C. leucas, N = 14). PRM rates ranged from 2% and 3% PRM in tiger and sandbar sharks to 42% and 71% PRM in blacktip and spinner sharks, respectively. Decision trees based on blood values predicted mortality with >67% accuracy in blacktip and spinner sharks, and >99% accuracy in sandbar sharks. Ninety percent of PRM occurred within 5 h after release and 59% within 2 h. Blood physiology indicated that PRM was primarily associated with acidosis and increases in plasma potassium levels. Total fishing mortality reached 62% for blacktip and 89% for spinner sharks, which may be under-estimates given that some soak times were shortened to focus on PRM. Our findings suggest that no-take regulations may be beneficial for sandbar, tiger, and bull sharks, but less effective for more susceptible species such as blacktip and spinner sharks.
3

Kelly, Michael L., Errol R. P. Murray, Caroline C. Kerr, Craig A. Radford, Shaun P. Collin, John A. Lesku, and Jan M. Hemmi. "Diverse Activity Rhythms in Sharks (Elasmobranchii)." Journal of Biological Rhythms 35, no. 5 (June 2020): 476–88. http://dx.doi.org/10.1177/0748730420932066.

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Sharks are an interesting group of vertebrates, as many species swim continuously to “ram” oxygen-rich seawater over their gills (ram ventilators), whereas other species “pump” seawater over their gills by manipulating buccal cavity volume while remaining motionless (buccal pumpers). This difference in respiratory physiology raises the question: What are the implications of these differences in lifestyle for circadian rhythms? We investigated the diel activity patterns of 5 species of sharks, including 3 ram ventilating species: the school shark ( Galeorhinus galeus), the spotted estuary smooth-hound ( Mustelus lenticulatus), and the spiny dogfish ( Squalus acanthias); and 2 buccal pumping species: the Port Jackson ( Heterodontus portusjacksoni) and draughtsboard ( Cephaloscyllium isabellum) sharks. We measured the amount, duration, and distance traveled while swimming over multiple days under a 12:12 light:dark light regime for all species and used modified light regimes for species with a clear diel rhythm in activity. We identified a surprising diversity of activity rhythms. The school shark and smooth-hound swam continuously; however, whereas the school shark swam at the same speed and covered the same distance during the day and night, the smooth-hound swam slower at night and traversed a shorter distance. A similar pattern was observed in the spiny dogfish, although this shark swam less overall. Both the Port Jackson and draughtsboard sharks showed a marked nocturnal preference for swimming. This pattern was muted and disrupted during constant light and constant dark regimes, although circadian organization of this pattern was maintained under certain conditions. The consequences of these patterns for other biological processes, such as sleep, remain unclear. Nonetheless, these 5 species demonstrate remarkable diversity within the activity rhythms of sharks.
4

Benson, C. W., B. D. Shea, C. de Silva, D. Donovan, P. E. Holder, S. J. Cooke, and A. J. Gallagher. "Physiological consequences of varying large shark exposure on striped bass (Morone saxatilis)." Canadian Journal of Zoology 97, no. 12 (December 2019): 1195–202. http://dx.doi.org/10.1139/cjz-2019-0173.

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Large marine predators often aggregate seasonally in discrete locations to take advantage of optimal foraging conditions, leading to spatial and temporal variation in their exposure on other species. However, our understanding of the impacts this exposure may have on the behavior and physiology of prey is poor, especially in marine systems. Here, we evaluated the non-consumptive effects of potential exposure to large sharks (white sharks, Carcharodon carcharias (Linnaeus, 1758)) on the stress physiology of an economically important teleost, the striped bass (Morone saxatilis (Walbaum, 1792)), off Cape Cod, Massachusetts, USA. We sampled fish in habitats that varied significantly in shark exposure across 5 months and over 2 years, evaluating blood physiology stress indicators (i.e., cortisol, glucose, and lactate concentrations) and reflex impairment. None of the blood parameters were influenced by shark exposure, although we did observe subtle temperature and seasonal effects. One of the three reflex tests (the vertical orientation test) was negatively affected by shark exposure, although the mechanistic basis for this finding is unclear. This work supports the notion that predictable sources of predation pressure tend not to manifest in stress-related costs in free-ranging prey, which has implications for shaping our understanding of how large sharks influence ecosystems through non-consumptive effects.
5

Johnston, Emmett M., Lewis G. Halsey, Nicholas L. Payne, Alison A. Kock, Gil Iosilevskii, Bren Whelan, and Jonathan D. R. Houghton. "Latent power of basking sharks revealed by exceptional breaching events." Biology Letters 14, no. 9 (September 2018): 20180537. http://dx.doi.org/10.1098/rsbl.2018.0537.

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The fast swimming and associated breaching behaviour of endothermic mackerel sharks is well suited to the capture of agile prey. In contrast, the observed but rarely documented breaching capability of basking sharks is incongruous to their famously languid lifestyle as filter-feeding planktivores. Indeed, by analysing video footage and an animal-instrumented data logger, we found that basking sharks exhibit the same vertical velocity (approx. 5 m s −1 ) during breach events as the famously powerful predatory great white shark. We estimate that an 8-m, 2700-kg basking shark, recorded breaching at 5 m s −1 and accelerating at 0.4 m s −2 , expended mechanical energy at a rate of 5.5 W kg −1 ; a mass-specific energetic cost comparable to that of the great white shark. The energy cost of such a breach is equivalent to around 1/17th of the daily standard metabolic cost for a basking shark, while the ratio is about half this for a great white shark. While breaches by basking sharks must serve a different function to white shark breaches, their similar breaching speeds questions our perception of the physiology of large filter-feeding fish.
6

Gallagher, Austin J., Erica R. Staaterman, Steven J. Cooke, and Neil Hammerschlag. "Behavioural responses to fisheries capture among sharks caught using experimental fishery gear." Canadian Journal of Fisheries and Aquatic Sciences 74, no. 1 (January 2017): 1–7. http://dx.doi.org/10.1139/cjfas-2016-0165.

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The response to capture is important in fisheries because it can reveal potential threats to species beyond fishing mortalities resulting from direct harvest. To date, the vast majority of studies assessing shark stress responses have used physiology or biotelemetry to look at sensitivity after capture, leaving a gap in our understanding of the behaviours of sharks during capture. We examined the behavioural responses of sharks to capture by attaching accelerometers to fishing gear and measuring the immediate and prolonged forces they exerted while on the line. We recorded acceleration vectors and derived the rate of intense fighting behaviours of 23 individual sharks comprising three species. Results suggest that blacktip sharks (Carcharhinus limbatus) exhibited intense bouts of fighting behaviour at the onset of hooking, while nurse (Ginglymostoma cirratum) and tiger sharks (Galeocerdo cuvier) displayed more subdued acceleration values during capture. We also obtained plasma lactate from a subset of individuals and detected a strong correlation with maximum acceleration. These results align with previously published values and suggest that shark movement during fisheries capture is an important factor during bycatch and catch-and-release interactions.
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Jacoby, David M. P., Penthai Siriwat, Robin Freeman, and Chris Carbone. "Is the scaling of swim speed in sharks driven by metabolism?" Biology Letters 11, no. 12 (December 2015): 20150781. http://dx.doi.org/10.1098/rsbl.2015.0781.

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The movement rates of sharks are intrinsically linked to foraging ecology, predator–prey dynamics and wider ecosystem functioning in marine systems. During ram ventilation, however, shark movement rates are linked not only to ecological parameters, but also to physiology, as minimum speeds are required to provide sufficient water flow across the gills to maintain metabolism. We develop a geometric model predicting a positive scaling relationship between swim speeds in relation to body size and ultimately shark metabolism, taking into account estimates for the scaling of gill dimensions. Empirical data from 64 studies (26 species) were compiled to test our model while controlling for the influence of phylogenetic similarity between related species. Our model predictions were found to closely resemble the observed relationships from tracked sharks, providing a means to infer mobility in particularly intractable species.
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Ritter, Erich. "Sharks and their Relatives II: Biodiversity, Adaptive Physiology and Conservation." Bulletin of Marine Science 87, no. 1 (January 2011): 155–56. http://dx.doi.org/10.5343/bms.br.2011.0001.

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Lowe, C. "Kinematics and critical swimming speed of juvenile scalloped hammerhead sharks." Journal of Experimental Biology 199, no. 12 (December 1996): 2605–10. http://dx.doi.org/10.1242/jeb.199.12.2605.

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Kinematics and critical swimming speed (Ucrit) of juvenile scalloped hammerhead sharks Sphyrna lewini were measured in a Brett-type flume (635 l). Kinematic parameters were also measured in sharks swimming in a large pond for comparison with those of sharks swimming in the flume. Sharks in the flume exhibited a mean Ucrit of 65±11 cm s-1 (± s.d.) or 1.17±0.21 body lengths per second (L s-1), which are similar to values for other species of sharks. In both the flume and pond, tailbeat frequency (TBF) and stride length (LS) increased linearly with increases in relative swimming speed (Urel=body lengths traveled per second). In the flume, tailbeat amplitude (TBA) decreased with increasing speed whereas TBA did not change with speed in the pond. Differences in TBF and LS between sharks swimming in the flume and the pond decreased with increases in Urel. Sharks swimming at slow speeds (e.g. 0.55 L s-1) in the pond had LS 19 % longer and TBF 21 % lower than sharks in the flume at the same Urel. This implies that sharks in the flume expended more energy while swimming at comparable velocities. Comparative measurements of swimming kinematics from sharks in the pond can be used to correct for effects of the flume on shark swimming kinematics and energetics.
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Mohan, John A., Nathan R. Miller, Sharon Z. Herzka, Oscar Sosa-Nishizaki, Suzanne Kohin, Heidi Dewar, Michael Kinney, Owyn Snodgrass, and R. J. David Wells. "Elements of time and place: manganese and barium in shark vertebrae reflect age and upwelling histories." Proceedings of the Royal Society B: Biological Sciences 285, no. 1890 (November 2018): 20181760. http://dx.doi.org/10.1098/rspb.2018.1760.

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As upper-level predators, sharks are important for maintaining marine food web structure, but populations are threatened by fishery exploitation. Sustainable management of shark populations requires improved understanding of migration patterns and population demographics, which has traditionally been sought through physical and/or electronic tagging studies. The application of natural tags such as elemental variations in mineralized band pairs of elasmobranch vertebrae cartilage could also reveal endogenous and exogenous processes experienced by sharks throughout their life histories. Here, elemental profiles were characterized in vertebrae encompassing complete life histories (birth-to-death) of shortfin mako ( Isurus oxyrinchus ), common thresher ( Alopias vulpinus ) and blue shark ( Prionace glauca ) of known tag and recapture locations in the eastern North Pacific Ocean. All sharks were injected with oxytetracycline at initial capture, released and subsequently recaptured, with individual liberty times ranging from 215 days to 6 years. Vertebral band pairs forming over the liberty intervals were verified by counting the number of band pairs deposited since the oxytetracycline band. Regular oscillations in vertebrae manganese (Mn) content corresponded well with the number of validated band pairs, suggesting that Mn variation could be used to age sharks. Increases in vertebrae barium concentration were correlated with times when individuals occupied areas with high coastal upwelling indices, the timing and spatial intensity of which varied from year to year. Interspecific relationships were probably influenced by behavioural differences in horizontal and vertical habitat use, feeding habits and thermoregulatory physiology. These results indicate that vertebral sclerochronology has the potential to advance our knowledge of elasmobranch life history including age and growth estimation and environmental reconstruction.

Дисертації з теми "Sharks Physiology":

1

Dowd, W. Wesley. "Metabolic Rates and Bioenergetics of Juvenile Sandbar Sharks (Carcharhinus plumbeus)." Text, W&M ScholarWorks, 2003. http://www.vims.edu/library/Theses/Dowd03.pdf.

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2

Gennari, Enrico. "Thermal physiology and behavioural ecology of the white shark, carcharodon carcharias." Thesis, Rhodes University, 2015. http://hdl.handle.net/10962/64002.

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3

Gardiner, Jayne M. "Multisensory Integration in Shark Feeding Behavior." Text, Scholar Commons, 2012. http://scholarcommons.usf.edu/etd/4046.

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Multimodal sensory input directs simple and complex behaviors in animals. Most research to date has been limited to studies of individual senses rather than multiple senses working together, leading to important advances in our comprehension of the sensory systems in isolation, but not their complementary and alternative roles in difficult behavioral tasks, such as feeding. In the marine environment, a prey item might emit an odor, create a hydrodynamic disturbance, such as from gill movements or swimming, be visible to the predator, produce a sound, and/or produce a weak electrical field. Therefore, the goal of this study was to investigate the integration of olfaction, mechanoreception by the lateral line system, vision, and electroreception in a marine animal. Sharks were chosen as a model organism in which to investigate multisensory integration because of their sensitivity and acuity, the presence of the same suite of sensory modalities in all species, the availability of experimental animals from different species, habitats and ecologies, and the rich literature on sharks' prey capture behavior. Two approaches were used: controlled artificial stimuli, delivered to the animals, were used to determine the spatial and concentration characteristics of odor encounters that guide the initial orientation to an odor plume in the far field in a model elasmobranch, the smooth dogfish, Mustelus canis; and sensory deprivation was used to restrict the availability of natural cues emanating from live prey items in order to elucidate the complementary and alternating roles of the senses in detecting, tracking, orienting to, striking at, and ultimately capturing prey. In the latter experiments, three species of sharks from different ecological niches were investigated: benthic, suction-feeding nurse sharks (Ginglymostoma cirratum) that hunt nocturnally for fish; ram-biting bonnetheads (Sphyrna tiburo) that scoop crustaceans off the bottom of seagrass beds; and ram-feeding blacktip sharks (Carcharhinus limbatus) that rapidly chase down midwater teleost prey. In orienting to odor patches, bilateral time differences between the nares are more important than concentration differences, such that animals turn toward the side stimulated first, even with delayed pulses of higher concentration. This response would steer the shark into each oncoming odor patch, helping the animal maintain contact with an odor plume. Sensory deprivation experiments revealed similarities and differences among species in terms of which senses they choose to focus on for particular behaviors, likely as a result of differences in the environments that they hunt in, type of prey consumed, and foraging strategies used, as well as anatomical differences in the central nervous system and the sensory organs. In most cases, multiple senses can be used for the same behavioral task. Thus, sharks are capable of successfully capturing prey, even when the optimal sensory cues are unavailable, by switching to alternative sensory modalities, which indicates that feeding behavior is plastic. Nurse sharks rely primarily on olfaction for detection. Olfaction in combination with vision, the lateral line, or touch is required for tracking. Nurse sharks orient to prey using the lateral line, vision, or electroreception, but will not ingest food if olfaction is blocked. Capture is mediated by the electrosensory system or tactile cues. Bonnetheads normally detect prey using olfaction, rely on olfactory-based tracking until they are close to the prey, then vision to line up a strike, and finally electroreception to time the jaw movements for capture. They can detect, orient, and strike visually in the absence of olfactory cues. Blacktip sharks also detect prey using olfaction or vision. Olfaction is used in combination with vision or the lateral line system for tracking. Long-distance orientation and striking is visually mediated, but strike precision relies on lateral line cues and an increase in misses occurs when this system is blocked. In the absence of vision, short-range orientation and striking can occur using lateral line cues. Capture is mediated by electroreception or tactile cues. Collectively, these results were used to develop species-specific sensory hierarchies for shark feeding behavior in a captive environment, the first such hierarchies to cover a complete behavioral sequence in a vertebrate.
4

Hoggatt, April Marie. "Mab anti-type I and Mab anti-zebrin II labelling in two siluriform fishes : the role of shared lineage versus shared function in polypeptide co-distributions." Virtual Press, 1994. http://liblink.bsu.edu/uhtbin/catkey/902481.

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Two monoclonal antibodies (mabs), the newly generated mab anti-type I and the previously documented mab anti-zebrin II, were reacted with brainstem sections of two ostariophysan siluriforms, the gymnotoid Rhamphichthys rostratus and the siluroid Ictalurus punctatus. Mab anti-type I recognizes a 47 kD polypeptide present in the dendrites and soma of projection neurons. Mab anti-zebrin II recognizes a 36 kD polypeptide present throughout the neuronal cytoplasm, including the axon. Strongly type I immunopositive cells include all cerebellar Purkinje cells, pyramidal cells of the nucleus medialis, electrosensory lateral line lobe, and tectum, pacemaker relay cells, Mauthner neurons, lateral line ganglion cells, and cells of the reticular formation, lateral reticular nucleus, and inferior olive. Weakly reactive type I cells include neurons in the torus semicircularis, medial and efferent octavolateralis nuclei, magnocellular and lateral tegmentum, and motor neurons of the Vth, V I Ith, and Xth cranial nerves. All type I positive cells are projection neurons. Zebrin II expression is restricted to subsets of two cell types which also express the type I antigen -- Purkinje cells and developing acousticolateralis pyramidal cells. Both of these neurons develop from the region of the rhombic lip. Thus, the mutual expression of the type I antigen can be explained by the shared function of projection neurons, while the common expression of the zebrin II antigen may be due to a shared embryological lineage.
Department of Physiology and Health Science
5

Tompkins, Linda Suzanne. "Molecular mechanisms of glucose-sensing shared by insulin-secreting cells and glucose-sensing neurons of the rat hypothalamus." Dissertation-Reproduction (electronic), The University of Arizona, 2000. http://hdl.handle.net/10150/279863.

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Fundamental to life is the ability to acquire and assimilate nutrients. Individual cell types exhibit preferences for different nutrients, but only certain cells utilize nutrients as signaling molecules. The most intensely studied nutrient signaling system is the pancreatic beta cell, which secretes insulin in response to changes in blood glucose. Another glucose sensing system is found in the neurons within the hypothalamus of the brain. To study how single cells sense changes in glucose, a sensitive marker for secretion is required. To this end the human Growth Hormone (hGH) gene was fused to the 5' end of the enhanced Green Fluorescent Protein (GFP) gene and expressed in the RIN-1038 beta (β)-cell line. The hGH-GFP fusion protein was targeted to secretory granules and its secretion into culture media was detected from cell populations. At stimulatory levels of glucose (5 mM), hGH-EGFP secretion doubled, and potentiators of insulin secretion enhanced glucose-induced hGH-EGFP release. However, at the single cell level, hGH-EGFP fluorescence acted as a sensor for changes in secretory granule pH. Glucose induced granule acidification by increasing activity of the V-type proton ATPase resident in the vesicular membrane. Moreover, potentiators of secretion elicited alkalinization of the vesicle lumen suggesting a mechanism by which they enhance release. To compare components of the glucose-sensing mechanism of hypothalamic neurons to those described for the beta cell, RT-PCR analysis was performed on RNA samples taken from the Arcuate nucleus (ARC), Lateral Hypothalamus (LH), Paraventricular Hypothalamus (PVH) and Ventromedial Hypothalamus (VMH). Tissue-specific expression of Glucokinase (GK), Glucokinase Regulatory Protein (GKRP), Glucose transporter isoforms (GLUT) 1, 2, 3 and X1 genes were determined. GK gene expression was found in all hypothalamic regions, with highest levels in the ARC. Enzymatic activity assays show that GK activity accounts for approximately 20% of the total soluble hexokinase activity in pooled samples of ARC and VMH. All regions also express GLUT 1, 3 and X1. However, no GLUT-2 or GKRP mRNA was detected in any sample. Because the expression of the low K(m) GLUTS predominates and GKRP expression is absent, the hypothalamic glucose-sensing mechanism is adapted to the lower levels of glucose present in the cerebrospinal fluid compared to blood levels.
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Bouyoucos, Ian. "Les effets des conditions du changement climatique prévues sur les requins tropicaux." Electronic Thesis or Diss., Université Paris sciences et lettres, 2020. TEL.

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Les requins sont menacés aux causes anthropiques ; mais, les conséquences qu’une menace nouveau, le changement climatique, sont mal connus. Pour ma thèse, j’ai testé l’hypothèse que le changement climatique agira sur les performances physiologiques des requins tropicaux pour réduire la valeur sélective. Mes objectives sont d’évaluer les effets des zones « nurseries » sur la performance physiologique, la performance physiologique in situ, les performances, préférences, et tolérances thermiques, et les effets du réchauffement et de l’acidification des océans sur la performance physiologique. J’ai trouvé que les requins pointes noires (Carcharhinus melanopterus) ont la croissance supérieure dans les zones nurseries mais l’acidification et le réchauffement agissent en synergie à la réduire. Mes résultats suggèrent que le changement climatique va réduire la valeur sélective des requins tropicaux par les effets sur les performances physiologiques qui sont associés aux zones nurseries
Myriad anthropogenic impacts drive declines in global shark populations; yet, the consequences of a newly recognised threat, global climate change, are poorly understood. This thesis tested the hypothesis that global change stressors (ocean acidification and warming) reduce fitness in tropical reef sharks via effects on physiological performance. My specific objectives were to define thermal performance in fitness-enhancing nursery areas, physiological performance in situ, associations between thermal performance, preference, and tolerance, and physiological performance under multiple global change stressors. I found that neonatal blacktip reef sharks (Carcharhinus melanopterus) have superior growth efficiency in nursery areas relative to other habitats, but ocean acidification and warming synergistically reduce performance. This thesis suggests that global change stressors reduce fitness in tropical reef sharks by acting on physiological traits that are associated with nursery areas
7

Brooks, Edward James. "Elasmobranch longline capture : ecological application, physiological impacts and alternative techniques." Electronic Thesis or Diss., University of Plymouth, 2013. http://hdl.handle.net/10026.1/1570.

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Longline fishing is the most common elasmobranch capture method in the world, both for commercial fishing, and to a lesser extent for scientific surveys. The capture of an animal on a longline initiates a series of physiological responses designed to promote survivorship in the short term, but if unchecked, can cause reduced individual fitness and/or mortality in the long term. Given widespread declines in shark populations, an improved understanding of the physiological costs of longline capture is needed. The aim of this thesis was to investigate the physiological response of sharks to capture and restraint, to assess novel, non-invasive alternatives to scientific longline surveys, and to generate scientific insight into poorly understood elasmobranch populations in The Bahamas. The results presented herein suggest that some species of shark are able to recover from the physiological stress of capture despite the presence of persistent negative stimuli. Tonic immobility was assessed as a means of generating baseline blood chemistry data, but was found to be inappropriate given that it increases the magnitude of physiological perturbation in the short term. To avoid the stress of capture altogether, Baited Remote Underwater Video Surveys (BRUVS) were considered as a non-invasive alternative to capture based surveys, however, it was concluded that they lack the resolution necessary to answer fine scale demographic questions. For the Caribbean reef shark, longline surveys yielded high resolution data allowing the identification of fine scale spatiotemporal shifts in demographic population structure with minimal cost (mortality). Nevertheless, the ethics of using capture based surveys on sensitive species are questionable when alternative techniques are available. Deep water sharks caught on longline surveys exhibited high mortality rates, however, for these very poorly understood species moribund specimens have great scientific value which in some cases can offset the high ecological costs of the surveys. The results presented in this thesis highlight the on-going need for improved biological and ecological research into the majority of elasmobranch populations, particularly with regards to anthropogenic interactions such as capture. Given the tenuous conservation status of many species, the acquisition of applied, management focused data should remain the priority of elasmobranch scientists.
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Hart, Hannah. "Molecular Identification and Functional Characteristics of Peptide Transporter 1 (PEPT1) in the Bonnethead Shark (Sphyrna tiburo)." Text, UNF Digital Commons, 2015. http://digitalcommons.unf.edu/etd/610.

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Many elasmobranchs are considered top predators with worldwide distribution, and in general these fish play an important role in the transfer of energy from the lower to the upper trophic levels within the marine ecosystem. Despite this, little research has been done regarding the rates of prey ingestion, digestion, and the processes of energy and nutrient absorption. Specifically understudied is enzymatic digestion within the intestinal brush border, which functions to break down macromolecules into smaller subunits for luminal absorption across the gastrointestinal epithelium. Given their carnivorous diet, the present study sought to expand knowledge on nutrient intake in elasmobranchs by focusing on the uptake of products of protein metabolism. To accomplish this, sequence encoding Peptide Transporter 1 (PepT1), a protein found within the brush border membrane (BBM) of higher vertebrates that is responsible for the translocation and absorption of small peptides released during digestion by luminal and membrane-bound proteases, was molecularly identified in the bonnethead shark (Sphyrna tiburo) using degenerate primers based on conserved portions of known PEPT1 sequences from other vertebrates. Sequence encoding Peptide Transporter 2 (PepT2) was also isolated from the S. tiburo scroll valve intestine using the same methodology. PepT1 was then localized using immunocytochemistry with rabbit polyclonal anti-rat PEPT1 in the esophagus, stomach, duodenum, scroll valve intestine, rectum, and pancreas. Vesicle studies were used to identify the apparent affinity of the transporter, and to quantify the rate of uptake by its H+-dependent cotransporter properties, using 3H-glycylsarcosine as a model dipeptide. The results of this study provide insight into the rate and properties of food passage within S. tiburo, and can lead to future work on topics such as physiological regulation of protein metabolism and absorption and how it may vary in elasmobranchs that exhibit different feeding strategies.
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Zaffaroni, Marta. "Modélisation des interactions plant-puceron, en considérant explicitement le rôle des pratiques agricoles : Pêche (Prunus persica) - puceron vert (Myzus persicae) comme cas d'étude An ecophysiological model of plant–pest interactions: the role of nutrient and water availability Maximizing plant production and minimizing environmental impact: comparing agricultural management scenarios with multi criteria decision analysis The role of vectors interference in a shared host-multi vector system." Electronic Thesis or Diss., Avignon, 2020. http://www.theses.fr/2020AVIG0723.

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Les pucerons modifient le développement des plantes et peuvent transmettre des virus, représentant ainsi une menace majeure pour les cultures. Il est possible de réduire la pression exercée par les pucerons sur les plantes et d’améliorer la production agricole en facilitant certains processus écologiques en plus ou en remplacement de l’utilisation de pesticides. Les modèles mathématiques peuvent aider à prédire la direction et la force de ces processus écologiques et ils peuvent révéler l’impact des modes alternatifs de gestion des cultures. La thèse proposée vise à développer des modèles mathématiques basés sur les processus, couplant la physiologie des plantes et la démographie des pucerons, afin de favoriser l’intensification écologique et de réduire l’utilisation des pesticides. Les modèles tiennent compte i) des interactions entre la plante et le puceron, alors que la plupart des modèles de culture ne prennent en compte que l’effet du ravageur sur la plante et non l’inverse, ce qui nuit à la compréhension de la lutte antiparasitaire via les pratiques culturales;et ii) de l’effet des pratiques culturales et du résultat en termes de récolte,questions qui sont généralement absentes dans les modèles écologiques. Je couple tout d’abord un modèle mécaniste de croissance des plantes avec un modèle de population des pucerons, je le calibre pour un système pêche-puceron vert et je l’utilise pour obtenir des informations sur les mécanismes qui sous-tendent la réponse des pucerons à la fertilisation et à l’irrigation. En outre, je développe un modèle épidémiologique qui tient compte explicitement de l’interférence entre deux pucerons vecteurs. J’applique ce modèle pour étudier l’effet de l’interférence inter-spécifique des pucerons dans la propagation des virus des plantes, en tenant compte de l’effet des pratiques agricoles
Aphids alter plant development and can transmit viruses, thus representing a major threat for crops. Aphid pressure on plant can be reduced and crop production can be enhanced by facilitating some ecological processes in addition, or in substitution, to the use of pesticides. Mathematical models can help in predicting the direction and strength of these ecological processes and they can reveal the impact of alternative ways of managing crops. The proposed thesis aims to develop process based mathematical models coupling plant physiology and aphid demography to drive ecological intensification and reduce the use of pesticides. The models consider i) interactions between plant and aphid, while most crop models only consider the effect of the pest on the plant and not vice versa hence impairing insights upon bottom-up pest control via cultural practices; and ii) the effect of cultural practices and the outcome in terms of harvest, issues that are usually absent in ecological models. Therefore, I firstly couple a mechanistic plant growth model with a pest population model, I calibrate it for a peach-green aphid system and I use it to get insights on the mechanisms behind the response of aphids to fertilization and irrigation. Furthermore, I develop an epidemiological model explicitly accounting for the interference between two aphid vectors. I apply the model to explore the effect of inter-specific aphid interference in shaping the spread of plant viruses, considering the effect of agricultural practices
10

Wåhlin, Peter. "Enhanching the Human-Team Awareness of a Robot." Student thesis, Mälardalens högskola, Akademin för innovation, design och teknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-16371.

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The use of autonomous robots in our society is increasing every day and a robot is no longer seen as a tool but as a team member. The robots are now working side by side with us and provide assistance during dangerous operations where humans otherwise are at risk. This development has in turn increased the need of robots with more human-awareness. Therefore, this master thesis aims at contributing to the enhancement of human-aware robotics. Specifically, we are investigating the possibilities of equipping autonomous robots with the capability of assessing and detecting activities in human teams. This capability could, for instance, be used in the robot's reasoning and planning components to create better plans that ultimately would result in improved human-robot teamwork performance. we propose to improve existing teamwork activity recognizers by adding intangible features, such as stress, motivation and focus, originating from human behavior models. Hidden markov models have earlier been proven very efficient for activity recognition and have therefore been utilized in this work as a method for classification of behaviors. In order for a robot to provide effective assistance to a human team it must not only consider spatio-temporal parameters for team members but also the psychological.To assess psychological parameters this master thesis suggests to use the body signals of team members. Body signals such as heart rate and skin conductance. Combined with the body signals we investigate the possibility of using System Dynamics models to interpret the current psychological states of the human team members, thus enhancing the human-awareness of a robot.
Användningen av autonoma robotar i vårt samhälle ökar varje dag och en robot ses inte längre som ett verktyg utan som en gruppmedlem. Robotarna arbetar nu sida vid sida med oss och ger oss stöd under farliga arbeten där människor annars är utsatta för risker. Denna utveckling har i sin tur ökat behovet av robotar med mer människo-medvetenhet. Därför är målet med detta examensarbete att bidra till en stärkt människo-medvetenhet hos robotar. Specifikt undersöker vi möjligheterna att utrusta autonoma robotar med förmågan att bedöma och upptäcka olika beteenden hos mänskliga lag. Denna förmåga skulle till exempel kunna användas i robotens resonemang och planering för att ta beslut och i sin tur förbättra samarbetet mellan människa och robot. Vi föreslår att förbättra befintliga aktivitetsidentifierare genom att tillföra förmågan att tolka immateriella beteenden hos människan, såsom stress, motivation och fokus. Att kunna urskilja lagaktiviteter inom ett mänskligt lag är grundläggande för en robot som ska vara till stöd för laget. Dolda markovmodeller har tidigare visat sig vara mycket effektiva för just aktivitetsidentifiering och har därför använts i detta arbete. För att en robot ska kunna ha möjlighet att ge ett effektivt stöd till ett mänskligtlag måste den inte bara ta hänsyn till rumsliga parametrar hos lagmedlemmarna utan även de psykologiska. För att tyda psykologiska parametrar hos människor förespråkar denna masteravhandling utnyttjandet av mänskliga kroppssignaler. Signaler så som hjärtfrekvens och hudkonduktans. Kombinerat med kroppenssignalerar påvisar vi möjligheten att använda systemdynamiksmodeller för att tolka immateriella beteenden, vilket i sin tur kan stärka människo-medvetenheten hos en robot.

The thesis work was conducted in Stockholm, Kista at the department of Informatics and Aero System at Swedish Defence Research Agency.

Книги з теми "Sharks Physiology":

1

Carrier, Jeffrey C. Sharks and their relatives II: Biodiversity, adaptive physiology, and conservation. Boca Raton, FL: CRC Press/Taylor & Francis, 2010.

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Domeier, Michael L. Global perspectives on the biology and life history of the white shark. Boca Raton: Taylor & Francis, 2012.

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3

Simons, Terry. The Baas Becking Geobiological Laboratory field trip to Shark Bay, W.A., July 1986: Observations and technical notes. Campbell, A.C.T., Australia: Dept. of Geography and Oceanography, University College, University of New South Wales, Australian Defence Force Academy, 1987.

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4

Bindi, Marco, Giada Brandani, Alessandro Dessì, Camilla Dibari, Roberto Ferrise, Marco Moriondo, and Giacomo Trombi, eds. Impact of climate change on agricultural and natural ecosystems. Florence: Firenze University Press, 2009. http://dx.doi.org/10.36253/978-88-8453-921-2.

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This book illustrates the main results deriving from fourteen studies, dealing with the impact of climate change on different agricultural and natural ecosystems, carried out within the Impact of Climate change On agricultural and Natural Ecosystems (ICONE) project funded by the ALFA Programme of the European Commission. During this project, a common methodology on several Global Change-related matters was developed and shared among members of scientific communities coming from Latin America and Europe. In order to facilitate this interdisciplinary approach, specific mobility programmes, addressed to post-graduate, Master and PhD students, have been organized. The research, led by the research groups, was focused on the study of the impact of climate change on various environmental features (i.e. runoff in hydrological basins, soil erosion and moisture, forest canopy, sugarcane crop, land use, drought, precipitation, etc). Integrated and shared methodologies of atmospheric physics, remote sensing, eco-physiology and modelling have been applied.
5

Sharks and their relatives II: Biodiversity, adaptive physiology, and conservation. Boca Raton: Taylor & Francis, 2010.

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6

Hamlett, William C. Sharks, Skates, and Rays: The Biology of Elasmobranch Fishes. The Johns Hopkins University Press, 1999.

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7

Sharks, skates, and rays: The biology of elasmobranch fishes. Baltimore: Johns Hopkins University Press, 1999.

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8

Berger, Melvin, and Gilda Berger. Scholastic Q & A: What Do Sharks Eat For Dinner? (Scholastic Question & Answer). Scholastic Reference, 2001.

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9

Ashley, Laurence M., and Robert B. Chiasson. Laboratory Anatomy of the Shark (Booth Laboratory Anatomy Series). 5th ed. William C Brown Pub, 1988.

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10

Berger, Melvin, and Gilda Berger. Scholastic Q & A: Do Tornadoes Really Twist? (Scholastic Question & Answer). Scholastic Reference, 2000.

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Частини книг з теми "Sharks Physiology":

1

Beyerlein, Peter. "Informational physiology of individual development." In The Routledge International Handbook of Shared Parenting and Best Interest of the Child, 129–41. Abingdon, Oxon; New York, NY: Routledge, 2021.: Routledge, 2021. http://dx.doi.org/10.4324/9781003140566-12.

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2

Forrest, John N., and Grant G. Kelley. "Chloride Secretion in the Shark Rectal Gland: A Model for Epithelial Adenosine Receptors." In Adenosine and Adenine Nucleotides: From Molecular Biology to Integrative Physiology, 211–18. Boston, MA: Springer US, 1995. http://dx.doi.org/10.1007/978-1-4615-2011-5_25.

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3

Bouyoucos, Ian A., and Jodie L. Rummer. "Improving ‘shark park’ protections under threat from climate change using the conservation physiology toolbox." In Conservation Physiology, 185–204. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780198843610.003.0011.

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Sharks and rays are among the most threatened aquatic vertebrate taxa. This is due to a combination of their slow generation times, exploitation within the fisheries, and habitat degradation. Climate change was added as an additional, major threat to sharks and rays in the first decade of the 21st century. While marine protected areas are becoming more widespread, managing and conserving sharks and rays is complicated. Yet, the conservation physiology toolbox can be used to address such challenges. Here, we highlight studies from the Physioshark project, a conservation physiology research programme initiated to understand how human-induced stressors, primarily climate change, will affect tropical sharks and rays and the consequences for the health and viability of populations. We also highlight how other research teams from around the world have taken physiological approaches to understanding conservation problems for sharks. We then emphasize the importance of public outreach and education about the conservation issues sharks encounter, the benefits of using social media to disseminate key concepts, publications, presentations, media, and successes, and we underscore the power of storytelling through digital media as an important means for attracting attention to research, which can result in support and action.
4

"Hormonal Regulation of Elasmobranch Physiology." In Biology of Sharks and Their Relatives, 329–64. CRC Press, 2012. http://dx.doi.org/10.1201/b11867-19.

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5

"Sensory Physiology and Behavior of Elasmobranchs." In Biology of Sharks and Their Relatives, 365–418. CRC Press, 2012. http://dx.doi.org/10.1201/b11867-20.

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6

Ballantyne, J. S., and J. W. Robinson. "CHONDRICHTHYES | Physiology of Sharks, Skates, and Rays." In Encyclopedia of Fish Physiology, 1807–18. Elsevier, 2011. http://dx.doi.org/10.1016/b978-0-12-374553-8.00043-5.

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7

Block, B. A. "PELAGIC FISHES | Endothermy in Tunas, Billfishes, and Sharks." In Encyclopedia of Fish Physiology, 1914–20. Elsevier, 2011. http://dx.doi.org/10.1016/b978-0-12-374553-8.00103-9.

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8

"Integrative Multisensor Tagging: Emerging Techniques to Link Elasmobranch Behavior, Physiology, and Ecology." In Biology of Sharks and Their Relatives, 281–306. CRC Press, 2012. http://dx.doi.org/10.1201/b11867-17.

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9

"Biology and Management of Dogfish Sharks." In Biology and Management of Dogfish Sharks, edited by John W. Mandelman and Marianne A. Farrington. American Fisheries Society, 2009. http://dx.doi.org/10.47886/9781934874073.ch20.

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Abstract.—To provide a synthesis of the physiological responses to otter-trawl capture in spiny dogfish <em>Squalus acanthias</em>, blood values from trawled individuals were evaluated against values from minimally stressed dogfish caught rapidly by hook and line (control). Values and analyses from published studies are considered along with those from the most expansive set of blood samples taken from dogfish captured by both methods to date. Significant impacts of trawling on dogfish blood physiology were reflected in all parameters excluding log plasma protein. Parameters for whole-blood acid–base status (pH, significant decrease; pO<sub>2</sub>, 45% decrease; pCO<sub>2</sub>, 82% increase), and the metabolite lactate anion (125% increase) were most perturbed relative to differences induced by the capture methods in other parameters. The concentrations of sera monovalent electrolytes (Na<sup>+</sup>, K<sup>+</sup>, Cl<sup>-</sup>) and glucose were significantly elevated by trawling, but not to the magnitude seen in other studies related to capture stress in fish. Significant elevations in hematocrit and reductions in blood urea nitrogen (BUN) concentrations were also observed subsequent to trawling. Overall, this capture method incited marked changes in blood physiology relative to values in minimally stressed dogfish. However, previous studies demonstrating high rates of posttrawl dogfish survival indicate that such changes are resolvable in this species prior to lethal consequences.
10

Casper, B. M. "HEARING AND LATERAL LINE | The Ear and Hearing in Sharks, Skates, and Rays." In Encyclopedia of Fish Physiology, 262–69. Elsevier, 2011. http://dx.doi.org/10.1016/b978-0-12-374553-8.00013-7.

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Тези доповідей конференцій з теми "Sharks Physiology":

1

Potkonjak, Veljko, Vladimir Petrović, Kosta Jovanović, and Dragan Kostić. "Human-Robot Analogy − How Physiology Shapes Human and Robot Motion." In European Conference on Artificial Life 2013. MIT Press, 2013. http://dx.doi.org/10.7551/978-0-262-31709-2-ch021.

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2

Amirouche, Farid, Mark Gonzalez, Wayne Goldstein, Adam Derhake, Barbara Dudas, and Madhuri Tanushri. "Computer Modeling of the Patellofemoral Joint Instability: Patella Inherent Geometry Influence on Stress and Loading." In ASME 2009 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2009. http://dx.doi.org/10.1115/sbc2009-206885.

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Despite a large range of surgical options, treatment of patellofemoral instability continues to be a challenging clinical problem. Currently, there have been a number of computer models developed to try and better define the stabilizing forces about the patellofemoral joint. However, most of these studies have focused on patellofemoral contact pressures, omitting evaluation of patellar stability in the first 30° of knee flexion. The purpose of this study was to reconstruct a pathologic and normative patellar shape within a computer model based on previously described morphologic ratios. We then applied physiologic force vectors to each patellar shape and calculated the stress and moment about each. We hypothesized that individuals with a pathologic patellar shape would have internal stress and moments about the patella which could predispose them to instability. We found that there were significant differences in patterns of stress, strain, and internal displacement about the control and study patellar shapes. This study suggests that a change of patellar shape could have significant effects on the stresses and moments about the patella. Future studies in which calculations of moments could be performed on a series of control and study patellar groups could further define this difference. Dynamic simulations of the control and study patellar shapes could also visually demonstrate the difference in patellar translation. In the future, the results of patellofemoral modeling could be applied to individual patients to more accurately detail an individual treatment plan.
3

Thuramalla, Naveen V., William I. Douglas, Prem Rachakonda, Jamey D. Jacob, and Charles F. Knapp. "Effect of Plunger Design on the Constricting Forces in an Adjustable Systemic to Pulmonary Artery Shunt." In ASME 2004 International Mechanical Engineering Congress and Exposition. ASMEDC, 2004. http://dx.doi.org/10.1115/imece2004-61127.

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Hypoplastic left heart syndrome (HLHS) is a leading cause of cardiac death among newborns, in which the entire left side of the heart is underdeveloped and unable to support the blood circulation. It is the most common type of single ventricle physiology (SVP) and an important need for an adjustable systemic to pulmonary artery (SPA) shunt. In order to achieve full range control of blood flow between the systemic and pulmonary circulation, an adjustable SPA shunt is being developed. SPA shunts are generally made from FDA approved polytetrafluroethylene (PTFE). A screw-plunger mechanism is being used to cause the desired constriction in the pressurized shunt. It is necessary to optimize the design of the plunger, in order to vary the cross-section of the shunt with minimum forces required. An in vitro set up consisting of a hydraulic circuit to have a constant inlet pressure to the shunt throughout the process and a certain post shunt pressure initially, plunger attached to the force gauge mounted on a stand to cause constriction and measure forces, a mounting stand to hold the shunt and its casing, a flow meter and pressure transducers, is used to determine the effect of various plunger tip shapes. It was observed that wider the plunger, lesser is the force required to cause the same reduction in flow. Flow-displacement-force variations for each plunger tip used are also presented. Results from this study will be used to determine the torque required to drive the screw plunger mechanism to cause the desired constriction.
4

Vruddhula, Varun, and Iman Borazjani. "3D Flow Simulations in a Simplified Right Ventricle Model." In ASME 2014 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/detc2014-35476.

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The right ventricle (RV) pumps the de-oxygenated blood to the lungs for oxygen absorption. Characterizing the RV geometry, its motion, and the ventricular flow is critical in assessing the heart’s health to provide important clinical diagnostic and prognostic information. However, RV flow has not been observed as closely as the flow in the left side of the heart. The current imaging techniques are limited in their ability to characterize the three-dimensional flow of blood through the heart. There is no single experimental technique available today capable of comprehensively quantifying the 3D flow pattern of blood in heart. As a result, there exists a need for computer simulations in order to understand the complex 3D flow pattern in the heart. In this paper, the sharp-interface immersed boundary method was used to carry out simulations of the flow in a simplified RV model. The reconstructed geometry of the RV was approximated to have a crescent-shape cross-section. In contrast to the previous work, in which the atrium was ignored, the atrium was added with an almost spherical shape attached above the RV. The RV motion was prescribed based on a model that produces physiologic flow waveforms for the RV. The simulations show a complex swirling flow pattern in the RV and the formation of a vortex ring during diastole.
5

Masuda, Michiaka, and Keigi Fujiwara. "Three Distinct Types of Morphological Responses of Cultured Vascular Endothelial Cells to Physiological Levels of Fluid Shear Stress." In ASME 2003 1st International Conference on Microchannels and Minichannels. ASMEDC, 2003. http://dx.doi.org/10.1115/icmm2003-1124.

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Vascular endothelial cells are known to respond to fluid shear stress. To gain insights into the mechanism of flow response by these cells, various types of in vitro devices in which endothelial cells can be cultured under flowing culture medium have been designed. Using such a device, one can apply known levels of (usually laminar) fluid shear stress to cultured endothelial cells. We have made two types of devices: a viscometer-based cone-and-plate flow apparatus and a parallel plate chamber. The cone-and-plate apparatus is used to do biochemical analyses of flow effects on cells while the parallel plate chamber is used to observe dynamic behavior of endothelial cells under flow. We were able to maintain confluent endothelial cell cultures under flow for over a week in the parallel plate flow apparatus. Using this chamber and high resolution time-lapse video microscopy, we studied morphological changes of endothelial cells exposed to different levels of fluid shear stress. We found that endothelial cells in a confluent monolayer exhibited three types of fluid shear stress level-dependent morphological and motile responses within a narrow fluid shear stress range between 0.1–10 dyn/cm2. Endothelial cells cultured under no flow exhibited variable shapes and no preferred orientation of their long cell axes and showed a jiggling motion. When exposed to fluid shear stress levels of below 0.5 dyn/cm2, endothelial cell morphology and motility were not affected. However, when fluid shear stress levels were increased to 2–4 dyn/cm2, they became polygonal and showed increased random-walk activity. Fluid shear stress over 6 dyn/cm2 caused endothelial cells to initially become polygonal and increase their random-walk activity, but they soon became elongated and aligned in the direction of flow. As the cells elongated and aligned, they migrated in the direction of flow. The average velocity of this directed cell migration was less than that of cells moving randomly under the same flow condition at earlier times. These observations indicate that endothelial cells are able to detect and respond to a surprisingly small change in fluid shear stress. It is possible that endothelial cell physiology in vivo is also regulated by small changes in fluid shear stress and that a fluid shear stress change of a few dynes per cm2 within a certain region of an artery could trigger atherogenesis in that particular location.

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