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1
Dickson, Nancy J. "The natural history and possible extirpation of Blanchard's Cricket Frog, Acris crepitans. blanchardi, in West Virginia." Huntington, WV : [Marshall University Libraries], 2002. http://www.marshall.edu/etd/descript.asp?ref=95.
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Thesis (M.S.)--Marshall University, 2002.Title from document title page. Document formatted into pages; contains ix, 115 p. with maps and illustrations. Includes vita. Includes bibliographical references (p. 34-40).
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Bayne, Kimberly Ann. "The natural history and morphology of the eastern cricket frog, Acris crepitans crepitans, in West Virginia." Huntington, WV : [Marshall University Libraries], 2004. http://www.marshall.edu/etd/descript.asp?ref=387.
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Thesis (M.S.)--Marshall University, 2004.Title from document title page. Document formatted into pages; contains vi, 103 p. including illustrations and maps. Includes bibliographical references (p. 100-103).
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Doak, Naomi C. "Phylogeography, Dispersal and Movement of Fleay's Barred Frog, Mixophyes fleayi." Thesis, Griffith University, 2005. http://hdl.handle.net/10072/365483.
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This thesis investigates historical and current dispersal in Mixophyes fleayi, an endangered, wet forest-restricted frog species, found exclusively on the Great Dividing Range of mid-eastern Australia. The phylogeographic structuring and genetic divergence among isolated forest fragments and the presence of multiple populations within continuous forest is used to investigate historical connectivity of populations and current dispersal. Indirect genetic methods as well as field based direct methods are also used to investigate dispersal and movement. These results are used to explore the consequences of dispersal in terms of conservation and management of the species. Few studies have investigated genetic differentiation between upland mesic rainforest areas in southern parts of Queensland, which potentially acted as historical refugia for rainforest dependant species. The broad scale investigation of genetic diversity and structure in M. fleayi, using sequence variation within the mitochondrial ND2 gene, revealed two scales of genetic structure. Two deeply divergent and geographically isolated lineages were found to group populations across the Brisbane River Valley, with isolation of the Conondale Range in the north from all other populations to the south. This can be attributed to regional isolation of rainforest fragments during the Pliocene. Lower levels of genetic variation and sequence divergence were found across forest fragments within the southern distribution of the species (Springbrook, Mount Barney, McPherson, Main, Upper Richmond and Nightcap Ranges), resulting from more recent fragmentation and restricted dispersal related to expansion and contraction of rainforest habitat during the Pleistocene.
Genetic structure among populations indicates that comparatively high levels of genetic differentiation exist on very small geographic scales relative to other amphibian species. These data suggest isolation by distance within forest fragments and significant genetic structuring between populations separated by more than two kilometres. Despite the relatively low vagility of individuals, terrestrial dispersal occurs among nearby streams, both within as well as across major catchments. The extent of shared subcatchment boundary between nearby streams provided some indication of the probability and magnitude of gene flow, with sites that share more subcatchment boundaries showing lower levels of genetic differentiation. The indirect genetic evidence of restricted dispersal within the species is supported by mark-recapture, spooling and radio-tracking investigations of movements made by individual M. fleayi in the field. The activity of both sexes is characterized by intervals of small, localized movements. In adult females this behaviour is punctuated by large movements that generally displace individuals away from breeding habitat after relatively short amounts of time spent at the stream. While migration of females between breeding sites was not detected, the movements made by adult females are large enough to enable dispersal between breeding sites, although such dispersal events are probably infrequent. Adult males are extremely philopatric and remain within the breeding area, rarely moving away from the stream, making exchange of adult males between populations extremely unlikely. The management of M. fleayi is particularly important given the potential impact recent declines in both population size and number may have had on genetic variation. Intraspecific genetic divergence, across the Brisbane River Valley, highlights the need to conserve populations in isolated forest fragments both north and south of this putative barrier. Within fragments of continuous forest habitat, evidence of restricted, infrequent terrestrial dispersal of individuals suggests colonization of vacant habitat is unlikely, particularly among streams that do not share subcatchment boundaries. To maintain important, albeit low levels of gene flow and movement between nearby streams, it is critical that habitat connectivity between populations is maintainedThesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Environmental and Applied Science
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Birchfield, Gayle Livingston. "Green frog (Rana clamitans) movement behavior and terrestrial habitat use in fragmented landscapes in central Missouri /." free to MU campus, to others for purchase, 2002. http://wwwlib.umi.com/cr/mo/fullcit?p3074372.
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Amish, Stephen Joseph. "Ecosystem engineering beaver and the population of Columbia spotted frogs in western Montana /." Connect to this title online, 2006. http://etd.lib.umt.edu/theses/available/etd-01172007-105600/.
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Sutton, William Bradley. "The ecology and natural history of the Northern Leopard Frog, Rana pipiens Schreber in West Virginia." Huntington, WV : [Marshall University Libraries], 2004. http://www.marshall.edu/etd/descript.asp?ref=458.
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Thesis (M.S.)--Marshall University, 2004.Title from document title page. Includes abstract. Document formatted into pages; contains viii, 110 including illustrations. Includes bibliographical references (p. 98-103).
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Paloski, Rori A. "Relationship between lakeshore development and anuran populations in Portage County, Wisconsin /." Link to full-text, 2006. http://epapers.uwsp.edu/thesis/2006/paloski.pdf.
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Vradenburg, John. "Distribution and abundance of anurans in southeast Missouri." Diss., Columbia, Mo. : University of Missouri-Columbia, 2005. http://hdl.handle.net/10355/4258.
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Thesis (M.S.)--University of Missouri-Columbia, 2005.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (January 10, 2007) Includes bibliographical references.
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Wu, Yuxin. "Bioactive peptides from Rana (Odorrana) frog secretions." Thesis, Queen's University Belfast, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.603569.
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The studies described in this thesis have focused on the bioactive peptides secreted from the skin glands of Rana (Odorrana) frogs, using different techniques to identify the sequences of novel peptides and to subsequently clone their precursors by molecular genetic techniques and finally, to chemically-synthesize these peptides and examine their bioactivities. Chapters I and 2, respectively, give a general introduction to the field of research and describe the scientific techniques employed in the work. The first experimental chapter, Chapter 3, describes two novel non-canonical bradykinin antagonist peptides isolated from the skin secretion of Odorrana versabilis which contain a "Rana box"-like structure at their C-terminals- a motif that is normally present in antimicrobial peptides. Chapter 4 describes a novel tachykinin peptide which was isolated from the skin of Rana chensinensis, and is strongly suspected of being an NKI receptor agonist. Chapter 5 describes the identification of two novel peptides from the skin secretions of Odorrana versabifis and Odorrana livida, which possess a moderate degree of specific antifungal activity. How their similar primary structures with only two residue substitutions, can cause an apparent 4-fold difference in potency is an interesting observation worthy of further indepth study. Chapter 6 describes a study that focuses on a Bowman-Birk trypsin inhibitor peptide from Odorrana schmackeri skin secretion and its position 9 substituted analogue. The most interesting result was the discovery of their multi-functional effects, not only against the proteases, trypsin and chymotrypsin, but also extending to growth inhibitory effects on cancer cell lines, tryptase inhibition and even to smooth muscle effects. The structure/function relationships of these peptides require further in-depth investigations. Chapter 7 describes a novel vasodilator peptide, named vasorelaxin, isolated from Odorrana schmackeri skin secretion with a potency approaching two orders of magnitude greater than canonical bradykinin. These data further illustrate that Rana (Odorrana) frogs skin secretions remain an important resource for novel peptide discovery, some of which may possess therapeutic properties.
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Hunter, David, and n/a. "Conservation Management of Two Threatened Frog Species in South-Eastern New South Wales, Australia." University of Canberra. Applied Science, 2007. http://erl.canberra.edu.au./public/adt-AUC20081020.142239.
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The decline and extinction of amphibian species over the past three decades is widely acknowledged as one of the greatest biodiversity crises of modem time. Providing convincing data to support hypotheses about these declines has proved difficult, which has greatly restricted the development and implementation of management actions that may prevent further amphibian declines and extinctions from occurring. In this thesis, I present research that was undertaken as part of the recovery programs for the southern corroboree frog (Pseudophryne corroboree), and the Booroolong frog (Litoria booroolongensis); two species that underwent very rapid declines in distribution and abundance during the 1980's. More specifically, I investigated potential causal factors in the declines of both species using experimental and correlative studies, and examined the mechanisms by which one threatening process (chytridiomycosis) may be causing continued decline and extinction in P. corroboree. I also examined the implications of population dynamics for monitoring L. booroolongensis, and suggest a possible monitoring strategy that may reliably facilitate the implementation of recovery objectives for this species. I also tested one possible reintroduction technique aimed at preventing the continued decline and extinction of P. corroboree populations.
In Chapters 2 and 3, I present the results from a series of experiments in artificial enclosures designed to examine whether the tadpoles of L. booroolongensis are susceptible to predation by co-occurring introduced predatory fish species; brown trout (Salmo trutta), rainbow trout (Oncorhynchus mykiss), European carp (Cyprinus carpio), redfin perch (Percafluviatilis), and mosquito fish (Gambusia holbrooki). I demonstrated that the tadpoles of L. booroolongensis, and a closely related species Litoria lesueuri, were palatable to non-native trout species, but not to two native predatory fish species, Gadopsis bispinosus and Galaxias olidus. A pond breeding frog species included in this experiment, Limnodynastes tasmaniensis, was palatable to both the native and non-native fish species. In a separate experiment I also demonstrated that the tadpole of L. booroolongensis is palatable to the three other introduced fish species examined in this study; C. carpio, P. fluviatilis, and G. holbrooki. In three of the experiments, the provision of rock within enclosures as a potential refuge habitat did not afford protection to L. booroolongensis tadpoles from
predation by any of the five introduced fish species examined. While all the introduced fish species tested here did consume L. booroolongensis tadpoles, the results also suggested that chemical unpalatability might afford some level of protection against some of these fish species. Firstly, the addition of alternative prey items in one of the experiments reduced the proportion of tadpoles consumed, suggesting that L. booroolongensis may not be a preferred prey item. Secondly, the proportion of tadpoles consumed varied greatly among the different fish species examined, suggesting differing levels of palatability. Overall, this study supports previous research in suggesting that chemical unpalatability may be an important strategy for the tadpoles of riverine frog species in south-eastern Australia to avoid predation by native fish species, and that this strategy is less effective against introduced fish species. While L. booroolongensis currently persists in streams inhabited by a number of introduced fish species, this study supports the likelihood that these species are having a negative impact on populations of L. booroolongensis in the wild.
In Chapter 4, I present the results of a study aimed at examining potential monitoring techniques for L. booroolongensis. The results of a mark-recapture exercise demonstrated that L. booroolongensis may exhibit large fluctuations in abundance from one year to the next, and through a prospective power analysis approach, I demonstrated that it would be difficult to confidently identify population trends of interest using either indices or estimates of abundance for this species. An assessment of the capacity to identify the presence or absence of L. booroolongensis using nighttime
spotlight surveys demonstrated the high detectability of this species using this technique, at both the scale of 300-meter sections of stream and individual breeding areas (typically less than 10-meters of stream). This study suggests that the monitoring objectives of the L. booroolongensis recovery program would be most effectively achieved using presence/absence surveys at different scales.
In Chapter 5, I present the results of a field survey aimed at determining the current distribution and habitat requirements of L. booroolongensis in the South West Slopes region of New South Wales. Of the 163 sites I surveyed across 49 streams,I located
L. booroolongensis along 77 of these sites from 27 streams. Based on population and habitat connectivity, this study identified 18 populations of L. booroolongensis that
are likely to be operating as independent populations. Twelve of these populations are not represented in conservation reserves, but rather occur along streams that flow through the agricultural landscape. A broad scale habitat analysis identified a positive relationship between extent of rock structures along the stream and the occurrence of
L. booroolongensis, and a negative relationship between the proportion of canopy cover and this species' occurrence. At the breeding habitat scale, this study identified a positive relationship between the presence of breeding males and; number of rock crevices in the aquatic environment, extent of emergent rocks, and proportion pool. This analysis also detected a negative relationship between occupancy and water depth. These results confirm previous work suggesting the importance of rocky stream habitats to the persistence of L. booroolongensis, but also suggest how disturbance processes, such as increasing sedimentation and weed invasion, may reduce the suitability of rocky structures as breeding sites.
In Chapter 6, I investigated current levels of amphibian chytrid fungus (Batrachochytrium dendrobatidis) infection in corroboree frog populations, and used retrospective screening of museum specimens to assess the possibility that this pathogen was implicated in the initial decline of the corroboree frogs. Using histology, I did not detect any B. dendrobatidis infections in corroboree frog populations prior to their decline, however using the same technique, moderate levels of infection were detected in post-decline populations of both species. Real-time PCR screening of skin swabs identified much higher overall infection rates in post-decline populations of P. corroboree (between 44% and 59%), while significantly lower rates of infection were observed in P. pengilleyi populations (14%). These results suggest that the initial and continued decline of the corroboree frogs may well be attributed to the emergence of B. dendrobatidis in populations of these species.
In Chapter 7, I investigated how B. dendrobatidis may be causing the continued decline of P. corroboree through the presence of an abundant reservoir host for this pathogen. I found that populations of adult C. signifera in sub-alpine bogs carry high
B. dendrobatidis infection rates (86%), but appear unaffected by this infection. An experiment involving the release of P. corroboree tadpoles into 15 natural pools resulted in metamorphs from seven of these pools testing positive for B. dendrobatidis, with all these individuals dying soon after metamorphosis. These
results support the possibility that B. dendrobatidis infection in P. corroboree populations is being facilitated by the presence of large numbers of infected C. signifera in the shared environment.
Chapter 8 presents the results of a population augmentation study for P. corroboree. I investigated the extent to which increasing recruitment to metamorphosis may result in population recovery in this species. This was undertaken by harvesting eggs from the field and rearing them through to mid stage tadpoles over the winter period prior to being released back to their natal ponds in spring. While I was able to increase recruitment to metamorphosis by an average of 20 percent, this did not result in a noticeable influence on the subsequent adult population size, as both manipulated and non-manipulated sites declined over the course of this study by an average of 80 percent. I observed a positive relationship between natural recruitment to a late tadpole stage and subsequent adult male population size, however there was considerable variation associated with this relationship. The relationship between recruitment and subsequent population size at the augmentation sites was consistent with the relationship observed at the non-manipulated sites. These results suggest that recruitment to metamorphosis may not be the most important life stage restricting the population recovery of P. corroboree, but that mortality during post-metamorphic stages may be more important in regulating current population size. Hence, further attempts to use captive rearing to increase P. corroboree populations in the wild should focus on the release of post-metamorphic frogs.
Overall, this thesis demonstrates the value of quantitative research to the implementation and progress of threatened species recovery programs. While this research will specifically contribute to the recovery programs for L. booroolongensis
and P. corroboree, it more broadly contributes to the understanding and capacity to respond to the concerning levels of amphibian extinctions currently occurring throughout the world.
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Benfer, David L. "Passive acoustic monitoring of calling activity provides an optimised field survey methodology for the threatened pouched frog, Assa darlingtoni." Thesis, Queensland University of Technology, 2017. https://eprints.qut.edu.au/104558/1/David_Benfer_Thesis.pdf.
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This project examined various methods for detection of the threatened pouched frog, Assa darlingtoni in south-east Queensland. By utilising automatic sound recording devices the project has provided valuable information on the calling behaviour of the species that will greatly aid in developing effective monitoring programs for this species and contribute to its conservation in the future.
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Rutherford, Mark Allen. "Synaptic exocytosis in the frog sacculus /." view abstract or download file of text, 2005. http://wwwlib.umi.com/cr/uoregon/fullcit?p3190546.
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Thesis (Ph. D.)--University of Oregon, 2005.Typescript. Includes vita and abstract. Includes bibliographical references (leaves 76 - 80). Also available for download via the World Wide Web; free to University of Oregon users.
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Bryer, Pamela J. "The Embryonic World of Wood Frogs, Rana Sylvatica: Natal Pond Learning and Anti-Predator Behaviors." Fogler Library, University of Maine, 2002. http://www.library.umaine.edu/theses/pdf/BryerPJ2002.pdf.
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Ruiz-Linares, Andres. "Processes of molecular evolution of the rDNA multigene family in Drosophila." Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239189.
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Whiting, Arthur. "Population ecology of the western chorus frog, Pseudacris triseriata." Thesis, McGill University, 2004. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=80896.
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The relationship between habitat preferences and rates of dispersal and directional orientation across different vegetations was investigated using captures from an array of drift fences for Pseudacris triseriata , at a breeding pond near Boucherville, Quebec. Growth rates for juveniles were similar across the study area, suggesting that food was not limiting and movement is related to habitat preference. Frog residence time in habitat enclosures, and between fence arrays was significantly longer for frogs in humid prairie vegetation compared to those in shrubby vegetation. The number of frogs caught per metre of fence in humid prairies was also on average higher than either shrubby or arid prairie vegetations. Together both migration rates and captures per metre of fence suggest that the preferred habitat for P. triseriata is humid prairie vegetation (e.g. Phalaris grass). Target-oriented dispersal may explain why similar numbers of P. triseriata were captured in both shrubby and humid prairie vegetation, despite the perceived preference for humid prairies over shrubby vegetation. The continued persistence of this population appears to be based on the recruitment of juveniles from the larval stage, and is also sensitive to the fecundity of the first time breeders.
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Pogson, Aimee L. "Tree Frog Madness." Bowling Green State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1245380440.
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Lee-Yaw, Julie A. "The phylogeographic history of the wood frog (Rana sylvatica) /." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=101598.
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Although the range dynamics of North American amphibians during the last glacial cycle are increasingly better understood, the recolonization history of the most northern regions and the impact of southern refugia on patterns of genetic diversity in these regions are not well reconstructed. In this study I present the phylogeographic history of a widespread and primarily northern frog, Rana sylvatica. For this study, 45 individuals from 34 localities were surveyed for a 700 b p. fragment of cytochrome b and 551 individuals from 116 localities were surveyed for 650 b.p. of the NADH dehydrogenase subunit 2 and tRNATRP mitochondrial genes. Phylogenetic analyses revealed two distinct clades corresponding to eastern and western populations. Phylogeographic patterns within each of these clades revealed similarities as well as differences from patterns found in other species. Specifically, the results corroborate eastern refugia located in the southern Appalachians near present-day North and South Carolina and in the interior plains in the lower Ohio River Valley. Current Maritime populations form a subclade amongst eastern populations and appear to have been colonized from the southern refugium. However, a more northern refugium located in the Appalachian highlands seems to have been source for most other northeastern wood frog populations. Rana sylvatica populations in the Great Lakes region appear to have been colonized from a western refugium located in present-day Wisconsin. This refugium was also a likely source for populations in the species' expansive northwestern range since there is no evidence to support additional, more western refugia.
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Cornell, Alan. "A regiocontrolled 1,3-dipolar cycloaddition approach to the 1-azaspiroundecanol framework of histrionicotoxin." Thesis, University of Reading, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326714.
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Swan, M. J. S. "The conservation ecology of Rana temporaria and Bufo bufo in Leicestershire." Thesis, De Montfort University, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.373434.
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Zhang, Ruowen. "Isolation and analysis of antimicrobial peptides from frog skins." Thesis, Queen's University Belfast, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.534592.
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Almhagen, Jimmy. "Anuran colonization of newly constructed ponds : The importance of time and distance to source populations." Thesis, Halmstad University, School of Business and Engineering (SET), 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-960.
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Dispersal is an important factor in animal ecology. Anurans (frogs and toads) are often philopatric (home loving) but some specimens in a population usually have the capacity to disperse relatively long distances. In this study I investigated the colonization of newly constructed ponds in the southwest of Sweden by three anuran species: The common toad (Bufo bufo), the moor frog (Rana arvalis) and the common frog (Rana temporaria). The ponds were constructed between two and five years ago and were now as frequently occupied as older source ponds in the area. For the common toad and the common frog there was no correlation between distance to source populations and degree of colonization. The moor frog was more common in ponds that were situated in the vicinity of older source ponds with ample populations. The main impression was that these species rapidly colonize newly constructed ponds, at least within moderate distances from source populations. There were some differences between the species though and it seems like the moor frog have more limited dispersal abilities than the other two species.
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Gray, Heather Marie. "Biological significance of colour pattern and variation in the green poison frog, Dendrobates auratus." Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=36941.
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The assumption that the colours of the green poison frog, Dendrobates auratus, serve as a warning of unpalatability is not supported because the requirements of the theory of aposematism are not met. The theory predicts that the aposematic coloration be conspicuous to potential predators, yet this cannot be demonstrated. The only predator found for D. auratus was the theraphosid spider, Sericopelma rubronitens, which hunts using vibrational cues. Only after sampling all frogs offered did spiders reject the toxic D. auratus over nontoxic Physalaemus pustulosus. The spider's decision to reject D. auratus as prey was made without visual input, and therefore the colours and toxicity of the frogs are decoupled with respect to this predator. Discovering that the crab Armases angustum is a predator of D. auratus tadpoles suggests that D. auratus is most vulnerable to predation during the nontoxic tadpole stage. Indirect methods of estimating predation were unsuccessful. The use of plasticine model frogs to estimate avian predation yielded no useful information and although traumatic injury is usually attributed to attempted predation, this is not true for tropical anurans. The levels of traumatic injury for D. auratus and a cryptic nontoxic frog Physalaemus pustulosus were similar when the life span of the frogs was taken into account. The traumatic injuries in these frogs are a function of interactions with small invertebrates that are neither predator nor prey. The theory of aposematism also predicts that there should be low pattern variation within an aposematic species so that a single search image can be formed and avoided. The patterns of D. auratus are individually distinct and there is significant interpopulational variation in appearance due to differences in colour, pattern and animal size. Selection for conspicuous visual intraspecific communication may have resulted in these differences in appearance. Mitochondrial 16S rRNA and cytochrome b sequence data ind
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Bracewell, Rob. "FROG and PS FROG : a study of two reactionless ocean wave energy converters." Thesis, Lancaster University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301820.
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Morrison, Fiona Clare, and n/a. "Altitudinal Variation in the Life History of Anurans in Southeast Queensland." Griffith University. School of Environmental and Applied Science, 2002. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20031125.120847.
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Global declines and disappearances of amphibians from high altitude, pristine habitats have been reported in recent years. To date the cause of many of these declines and/or disappearances has not been identified. Although it is well documented that life history characteristics of temperate amphibians are influenced by altitude (due to systematic variation of temperature with altitude), little work has been carried out on the effects of altitude on Australian anurans. This lack of ecological data is a major impediment to identifying the causal factors responsible for amphibian declines. Due to differences in life history characteristics, high altitude populations may be less resilient than their lowland counterparts and subsequently may be more vulnerable to extinction. Consequently, the main aim of this study was to determine whether altitude influenced life history characteristics and ultimately population resilience of anurans in the southeast Queensland region. Six anuran species; Litoria chloris, L. lesueuri, L. pearsoniana (Anura: Hylidae), Mixophyes fasciolatus, M. fleayi and M. iteratus (Anura: Myobatrachidae) were studied over three field seasons (1997-1999) in 18 sites of varying altitude (100-950m) in the southeast Queensland region. The life history characteristics examined were: activity and breeding season length, fecundity and egg size, number of clutches produced per season, tadpole growth and development rates, longevity, age at maturity, reproductive life span, average lifetime fecundity, survival and recapture rates. The data were collected using a combination of field-based surveys (body sizes, clutch sizes, and survival and recapture rates), museum specimen dissections (clutch and egg sizes), reciprocal transplant field experiments (tadpole growth and development rates) and skeletochronology (longevity, age at maturity, reproductive lifespan and average lifetime fecundity). On average, high altitude populations of all species had shorter breeding and activity seasons than low altitude populations (up to 10 weeks less in some cases). The magnitude of the difference in breeding season length varied among years depending on the average temperature and rainfall for the year; i.e. differences appeared greater in warmer and wetter years. Within a population males had longer breeding and activity seasons than females. Although breeding season length varied with altitude, the number of nights that individuals were active within the breeding season did not vary; i.e. low altitude populations were not active for more nights despite having a longer breeding season. This result was attributed to the absence of a relationship between individual activity and environmental variables (air temperature, rainfall, etc.) in many of the populations. Generally, intraspecific clutch size did not vary significantly with altitude. This result was due to the absence of a significant relationship between female body size and altitude (as clutch size is proportional to female body size). Egg size also did not vary with altitude however, suggesting egg size may be canalized (i.e. fixed) in these species. Results also suggest that females of these species only produce one clutch of eggs per season. Interspecific differences in reproductive characteristics largely reflected differences in reproductive mode, larval habitat and female body size. Altitude negatively influenced growth and development rates in L. chloris and development rates in L. pearsoniana. Tadpoles raised at high altitudes were also generally larger at each Gosner Development Stage in both species. The results of the reciprocal transplant experiments suggested that most of the variation in growth and development rates was due to environmental factors (water temperature) rather than genetic or maternal factors. Altitude or genetic factors did not significantly affect tadpole survival in either species. The results suggest that tadpoles occurring at high altitudes take longer to reach metamorphosis and do so at a larger size than their lowland counterparts. With the exception of L. lesueuri, skeletochronology was suitable for age estimation in the study species. Altitude had a significant effect on the age at maturity or longevity in some of the species, however there were trends toward older individuals and older ages at maturity in high altitude populations for the remaining species. Females were generally older than males for all species and in the case of longer-lived species (i.e. Mixophyes spp.) also tended to be older when breeding for the first time. The large overlap of body sizes of individuals of different ages demonstrates that body size is a poor indicator of age in these species. This is the first study to estimate average lifetime fecundity for more than one amphibian species and/or population. The results suggest that the absence of significant altitudinal variation in the average lifetime fecundity of different populations is due to tradeoffs made by females (current reproduction vs. survival). There was no significant altitudinal variation in annual survival and recapture rates in any of the species, and generally there was no difference in the survival and recapture rates of males and females in each population. Within a year, monthly survival and recapture rates were more variable at low than high altitudes and this was attributed to the longer breeding season of low altitude populations. The results did not support previous studies that suggested there was a size bias in survival and recapture rates. The shorter breeding seasons, slower growth and development rates, older age at maturity and greater longevity found in the high altitude study populations will result in increased generation time in those populations. In turn, increased generation time can cause high altitude populations to be less resilient (i.e. population takes longer to return to equilibrium after a disturbance away from equilibrium) (Pimm et al. 1988, Pimm 1991) and ultimately more vulnerable or prone to extinction or decline. The majority of unexplained global amphibian declines have occurred at high altitudes in tropical and subtropical areas. These latitudinal patterns may be explained by the narrow range of environmental tolerances exhibited by tropical organisms resulting in mountains being effectively higher in the tropics. Consequently, high altitude tropical species are likely to be even more vulnerable than temperate species occurring at similar altitudes. Further work on the effects of geographic variation, especially interactions between altitude and latitude are needed to evaluate the hypotheses for the causes of these declines and disappearances.
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Wright, Edgar António Policarpo. "Genetic algorithm for fiber-FROG using simulated pulse propagation." Master's thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/14277.
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Mestrado em FísicaIn this thesis a genetic algorithm for two dimensional phase reconstruction is implemented, based on frequency-resolved optical gating using the fibre-FROG geometry. A new parameter, termed fibre-FSR, is proposed to improve the algorithm’s convergence, and tested for 9 pulses with timebandwidth products between 0.604 and 7.047. Two of these pulses, centred about 1556 nm, with a full width at half maximum of 100 fs and an energy of 24 pJ are also reconstructed solving the pulse’s propagation equations numerically at each iteration in the algorithm, over 2 m of dispersion-shifted fibre with 𝛾 =2.36 W−1 km−1 and 𝛽2 = −804.78 fs2 m−1.
Nesta tese é implementado um algoritmo genético para fazer uma reconstrução de fase a duas dimensões com base na variante da técnica de frequency-resolved optical gating conhecida como fibre-FROG. Um novo parâmetro, denominado fibre-FSR, é proposto com o intuito de melhorar a convergência do algoritmo, e testado para 9 pulsos com parâmetros timebandwidth product compreendidos entre 0.604 e 7.047. Dois destes pulsos, centrados em 1556 nm, com uma largura a meia altura de 100 fs e uma energia de 24 pJ são também reconstruídos resolvendo numericamente, a cada iteração do algoritmo, as equações de propagação para 2 m de dispersionshifted fibre com 𝛾= 2.36 W−1 km−1 e 𝛽2 = −804.78 fs2 m−1.
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Kolozsvary, Mary Beth. "Hydroperiod of Wetlands and Reproduction in Wood Frogs (Rana sylvatica) and Spotted Salamanders (Ambystoma maculatum)." Fogler Library, University of Maine, 2003. http://www.library.umaine.edu/theses/pdf/KolozsvaryMB2003.pdf.
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Doak, Naomi C. "Phylogeography, dispersal and movement of Fleay's Barred Frog, Mixophyes fleayi." Click here to access, 2005. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20060221.144328.
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Clarke, B. T. "Evolutionary relationships of the discoglossoid frogs - osteological evidence." Thesis, London Metropolitan University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.233519.
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The discoglossoid Frogs (Discoglossidae and Leiopelmatidae) are generally considered to be the most primitive of the living frogs. Previous authors have grouped them on the basis of common possession of a limited number of primitive features of little phylogenetic significance, leaving the question of intra-discoglossoid relationships uncertain. The present study is a re-examination df the supraspecific relationships in the superfamily using computer-aided cladistic analyses of a large set of osteological data - specifically 95 characters (153 binary characters) in 21 modern discoglossoid taxa. Where possible, characters are assigned a polarity, principally using urodeles as the outgroup. Evolutionary relationships are inferred from the congruence of cladograms generated from compatibility and parsimony analyses of the data set. In an introductory section, modern approaches to systematic analysis and classification are reviewed and a justification for the chosen method is provided. The concepts of natural taxa and natural classifications are discussed, criteria for hypothesizing character polarities and accounts of compatibility and parsimony analysis methods are given • •A. remarkable degree of congruence' between the cladograms produced from a Le Quesne compatibility analysis and a Wagner parsimony analysis is evident. Results suggest:- (a) The leiopelmatid genera Ascaphus and Leiopelma are a sister pair but are probably only weakly related. (b) The modern DiBcoglossidae is a monophyletic group in which Alytes is sister to Bombina + Barbourula + Discoglossus. (c)Discoglossus is sister to Bombina + Barbourula. (d)Bombina and Barbourula are a sister pair. (e)All the discoglossoid genera are monophyletic. (f)Bombina comprises two species groups: small (B. bombina - B variegata - B orientalis) and large species (B maxima and B microdeladigitora). Comparisons are made with previous work and an overview hypothesis of the historical zoogeography of the discoglossoid frogs is presented.
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Buckler, K. J. "Actions of adrenergic agonists on transmembrane ion exchanges in skeletal and heart muscle." Thesis, University of Newcastle Upon Tyne, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.380754.
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Ahmed, Nadeem M. "Transgenic analysis of the endodermin promoter in Xenopus laevis." Thesis, University of Warwick, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269083.
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Hemming, D. J. "An immunological study of the role of histones in lampbrush chromosome structure." Thesis, University of Liverpool, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383516.
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Tyrrell, E. "Approaches to the synthesis of histrionicotoxin." Thesis, University of Southampton, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235209.
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Mason, M. J. "Mechanisms of entry of L-lactate into frog skeletal muscle : A micro-electrode study." Thesis, University of Bristol, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.375026.
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Spear, Stephen Frank. "Landscape genetics of habitat alteration across multiple spatial and temporal scales in the Anuran genus Ascaphus." Pullman, Wash. : Washington State University, 2009. http://www.dissertations.wsu.edu/Dissertations/Spring2009/s_spear_042909.pdf.
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Lowe, Katrin. "Landscape Ecology and Bioclimatic Conditions of the Wallum Sedge Frog (Litoria olongburensis) in Coastal Wallum Wetlands of Eastern Australia: Resilience to Climate Change." Thesis, Griffith University, 2013. http://hdl.handle.net/10072/366084.
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Many species are threatened by rapidly changing climate and amphibians may be particularly vulnerable. As ectotherms, all aspects of amphibian physiology and life history are directly or indirectly influenced by temperature and moisture. For amphibian conservation, a clear priority is to investigate impacts of climate change on key environmental parameters within breeding habitats, as well as the ecology of threatened species. This information is vital for assessing species vulnerability to climate change and informing conservation efforts. Wallum frogs are species that are restricted to naturally acidic, oligotrophic coastal wetlands of eastern Australia. There is a paucity of ecological data on wallum frogs and their breeding habitats however climate change predictions suggest they are likely to be exposed to changes in the timing and intensity of precipitation, and increases in temperature. Consequently, the aim of this study was to enhance our understanding of the bioclimatic conditions of threatened wallum frogs at a landscape scale. This information was then used to assess climate change vulnerability for these wallum associated frog species, particularly the threatened wallum sedge frog (Litoria olongburensis). This study determined environmental factors influencing reproductive behaviours of L. olongburensis, namely calling phenology and breeding effort. Also, the impacts of fire on wallum frog ecology and morphology were assessed, as their habitat is exposed to regular and intense fires, which are predicted to increase in frequency and/or severity in the future.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Griffith School of Environment
Science, Environment, Engineering and Technology
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Dyck, Amber. "Ditch Management in Agroecosystems: From Water Quality to Frog Health." Thesis, Université d'Ottawa / University of Ottawa, 2020. http://hdl.handle.net/10393/40969.
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Agriculture ditch management (i.e. removal of vegetation and/or sediments) may disturb native wildlife, such as amphibian bioindicator species. The objective of this thesis was to determine whether ditch management affected northern leopard frogs (Lithobates pipiens). Twelve embryo and tadpole health endpoints were compared in vegetated and managed (treeless or dredged) ditches using in situ cages in 2018 and 2019, while water quality was monitored. The managed treatment did not negatively affect frog health compared to the vegetated treatment. The significantly faster development and larger body size due to warmer water temperatures at the managed treatment were likely advantageous. The water quality was typical of the region regardless of the ditch treatment and the pesticide mixture detected had limited toxicity. The main effects of the studied ditch managements on resident L. pipiens (and potentially other amphibians) appeared sub-lethal, likely beneficial, and mainly the result of temperature differences. Although poorer embryo health was observed at the vegetated treatment, it was likely unrelated to ditch management and possibly due to high specific conductivity causing premature hatching and mortality. Ditch management may be less important for frog health than the surrounding land use, and efforts should be directed at increasing suitable habitat for amphibians in agroecosystems. La gestion des fossés agricoles (plus spécifiquement l'élimination de la végétation des bandes riveraines et /ou le dragage des sédiments) peut perturber la faune indigène, comme les espèces bio-indicateurs d'amphibiens. L'objectif de cette thèse était de déterminer si la gestion des fossés affectait la grenouille léopard du Nord (Lithobates pipiens). Douze paramètres d'évaluation de la santé des embryons et des têtards ont été comparés dans des fossés végétalisés et gérés (sans arbres ou dragués) à l'aide de cages expérimentales in situ en 2018 et 2019, pendant que la qualité de l'eau a été suivie. Le traitement géré n'a pas eu d'effets négatifs sur la santé des grenouilles par rapport au traitement végétalisé. Le développement beaucoup plus rapide et la taille corporelle plus grande en raison des températures plus chaudes de l'eau lors du traitement géré étaient probablement avantageux. La qualité de l'eau était typique de la région quel que soit le traitement du fossé et le mélange de pesticides détecté avait une toxicité limitée. Les principaux effets de la gestion des fossés étudiés sur L. pipiens résidents (et potentiellement d'autres amphibiens) semblaient sublétaux, probablement bénéfiques, et résultaient principalement de différences de température. Bien que la santé des embryons ait été moins bonne lors du traitement végétalisé, elle n'était probablement pas liée à la gestion des fossés et pourrait être due à une conductivité spécifique élevée entraînant une éclosion prématurée et la mortalité. La gestion des fossés peut être moins importante pour la santé des grenouilles que l'utilisation des terres environnantes, et les efforts de protection devraient être dirigés vers une augmentation générale de l'habitat approprié pour les amphibiens dans les agroécosystèmes.
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Davis, Robert A. "Metapopulation structure of the Western Spotted Frog (Heleioporus albopunctatus) in the fragmented landscape of the Western Australian wheatbelt." University of Western Australia. School of Animal Biology, 2004. http://theses.library.uwa.edu.au/adt-WU2005.0026.
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[Truncated abstract] Amidst concern over the global phenomenon of declining amphibians, there is an increasing appreciation of the importance of understanding population dynamics at both local and regional scales. Data on the viability and persistence of species in landscapes altered by humans are scarce but an understanding of these dynamics is essential for enabling long-term species conservation in a modified world. Habitat loss, fragmentation and ensuing salinisation are of particular concern for species in Australia’s temperate agricultural regions where the rapid conversion of continuously vegetated landscapes to small fragments has occurred in less than 200 years. This thesis investigated the local and metapopulation structure of Heleioporus albopunctatus to determine the current population structure and likely future of this species in a highly degraded landscape: the wheat and sheep growing areas of southwestern Australia ... The life-history attributes of H. albopunctatus, including high fecundity, high adult longevity and low to moderate dispersal contribute to a robust regional metapopulation, responsive to changes, but with a strong chance of persistence over the long-term. H. albopunctatus appears to have adjusted to a radically modified landscape but its long-term persistence may be dependent on the existence of a small number of source populations that recruit in most years.
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Cummins, Clive Patrick. "The impact of acid conditions on the common frog, Rana temporaria." Thesis, Open University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.276728.
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Wu, Di. "Genomic and bioinformatic studies on bioactive peptides from frog skin secretions." Thesis, Queen's University Belfast, 2017. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.728832.
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The modern drug industry has advanced to a new frontline. Peptide-based drugs are now seriously considered because of their multifarious structures and high affinity for many targets, as well as the fact that these agents have previously provided natural lead compounds for blockbuster drug development. Amphibian skin secretions are unique sources of bioactive molecules, particularly bioactive peptides. These bioactive peptides, especially antimicrobial peptides, have attracted much attention during the past decades. The disruption and permeabilisation of microbial cell membranes are the most effective ways of antimicrobial peptides to prevent microbes from developing resistance because the composition of microbial membranes is evolutionarily stable, making it less likely to acquire resistance through mutation. This important natural property of antimicrobial peptides represents a fundamental quality for therapeutic potential. To date, more than 2741 naturally occurring active peptides are included into the Antimicrobial Peptide Database and more than one-third of these are from amphibians. In this study, genomic, peptidomic and bioinformatic techniques have been employed to investigate the bioactive peptides from the skin secretions of several species of frogs, the white-lipped giant tree frog, Litoria infrafrenata from Australasia, the green cascade frog, Odorrana livida, from Asia and the Northern tiger-legged monkey leaf frog, Phyllomedusa hypochondrialis, from South America. By isolating skin secretion-derived mRNAs, cDNA libraries were constructed, peptide precursor genes were cloned and their encoded mature peptides were deduced from these genetic templates and their presence in skin secretions confirmed using reverse-phase HPLC, MALDI-TOF MS and MS/MS fragmentation sequencing. The peptides and their modified analogues were chemically-synthesised for evaluating their bioactivities and investigating their initial structure-activity relationships. The synthetic peptides showed varied bioactivities. The native frenatins from L. infrafrenata were found lacking in antimicrobial activity, however, their designed analogues exhibited broad-spectrum antimicrobial activity. The livisin from 0. livida, belonging to the Bowman-Birk like inhibitor family,possessed trypsin inhibitory activities. DLP-PH from P. hypochondrialis, was identified as a prototype of a novel family of AMP, with a potent broad-spectrum antimicrobial activity, especially against Gram-negative bacteria. A moderate anti-biofilm activity was also observed for this peptide. Moreover, DLP-PH exhibited anti-proliferation activity on certain human cancer cell lines without toxicity to normal human cells. Amphibian skin secretion is thus a quite remarkable source for the discovery of diverse novel bioactive peptides, some of which may have great potential in drug discovery and development.
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Long, Qilin. "Biological activities and antidiabetic potential of novel peptides from frog secretions." Thesis, Queen's University Belfast, 2018. https://pure.qub.ac.uk/portal/en/theses/biological-activities-and-antidiabetic-potential-of-novel-peptides-from-frog-secretions(032f6f90-8903-46fe-b26b-ac5b4dfaed78).html.
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The utilisation of natural products as drugs for the treatment of diseases and injuries has developed for thousands of years, but the current pharmaceutical system is predominately occupied by chemical-based drugs, while natural products are rarely applied. Since the widespread of antibiotic resistance and prevalence of chronic and malignant diseases (such as diabetes and cancers), there has been a significant rise of interest in discovering novel drug candidates with potent efficiency in treating these diseases. The amphibian skin, a special morphological and physiological organ, acts as the first line of defence against physical stimuli and lethal invasions. It is a rich source of pharmacological alternatives, some of which possess the potential to be developed in medical applications. In this study, both genomics and proteomics techniques have been used to study the frog skin secretions from the Burmeister’s leaf frog, Phyllomedusa burmeisteri; the hylid frog, Phyllomedusa sauvagei and the Chinese tiger frog, Hoplobatrachus rugulosus. More specifically, the molecular cloning strategy was performed to isolate target mRNAs, establish corresponding cDNA libraries and eventually clone unique peptide precursor-encoding cDNA sequences. Also, the mature peptides were analysed and confirmed via RP-HPLC, MALDI-TOF mass spectrometry and MS/MS fragmentation sequencing. After the peptide primary structure characterisation, synthetic replicates of each peptide were purified before applied for further secondary structural analysis and biofunctional assessments. The secondary structure conformations were determined by circular dichroism, and the functional analysis in this study includes the antimicrobial assay, MTT assay, haemolysis assay, insulinotropic assay and GLP-1 releasing assay. This study reports the isolation, identification and characterisation of one phylloseptin peptide Phylloseptin-PBu, one dermaseptin peptide Dermaseptin-PS1 and four tigerinin peptides (Tigerinin-HR1 to Tigerinin-HR4), they exhibited distinct biological activities. In Chapter 3, the detailed function and correlative mechanisms of novel phylloseptin peptide Phylloseptin-PBu were described. We showed that Phylloseptin-PBu could induce a dose-dependent insulinotropic activity in BRIN-BD11 cells, which is regulated by ATP-sensitive potassium channel depolarisation triggered extracellular calcium influx and GLP-1 receptor-initiated PKA signalling activation. In Chapter 4, the novel Dermaseptin-PS1 was demonstrated to possess anticancer capability in U251MG cells through the induction of intrinsic apoptosis at low concentrations (10-6M), but disrupting the cell membranes at high concentrations (≥10-5 M). In Chapter 5, GLP-1 release activity was observed after the treatment of peptide concentration gradient of four novel tigerinin peptides (Tigerinin-HR1 to Tigerinin-HR4) in STC-1 cells. These discoveries enriched the foundational knowledge of biological peptides from these three-frog species and might contribute to future drug development. This thesis includes six chapters, the Chapter 1 and Chapter 2 are general introduction and general materials and methods, respectively; the Chapter 3 to Chapter 5 are specific experimental chapters; and the Chapter 6 is general discussion chapter.
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Beatini, Salvatore J. "Using DNA fingerprinting to assess genetic structure of the vernal pool amphibian rana sylvatica." Link to electronic thesis, 2003. http://www.wpi.edu/Pubs/ETD/Available/etd-0428103-153026.
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Thesis (M.S.)--Worcester Polytechnic Institute.Keywords: wood frog; vernal pool conservation; fragmented habitat; Rana sylvatica; DNA fingerprinting. Includes bibliographical references (p. 38-40).
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Reis, Marcelo Felisberto dos. "Detecção molecular de Ranavirus em espécies de anfíbios anuros selvagens da região centro-leste do estado de São Paulo." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/74/74131/tde-03072018-134535/.
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O objetivo do trabalho foi realizar investigação sobre ocorrência de ranavirose, infecção causada por vírus do gênero Ranavirus, família Iridoviridiae, em anfíbios anuros silvestres nos municípios de Porto Ferreira e Pirassununga, cidades da região centro-leste do estado de São Paulo, Brasil, utilizando diagnóstico molecular. Ao todo, 40 anuros adultos silvestres da espécie Leptodactylus fuscus foram capturados nos municípios citados, sendo coletados três órgãos alvos (fígado, baço e rins) de replicação viral, com registro de eventuais alterações macroscópicas nesses órgãos, e dos quais extraiu-se DNA. Na sequência, realizou a reação em cadeia pela polimerase (PCR), utilizando-se primers específicos para o gene MCP (major capsid protein) de Frog Virus 3 (FV3), ranavírus circulante no Brasil, com isolado de FV3 pertencente ao biobanco do Laboratório de Higiene Zootécnica da FZEA-USP empregado como controle positivo e água livre de nuclease como controle negativo. Como resultados, em relação às alterações macroscópicas, somente um espécime apresentou hepatoesplenomegalia e hipopigmentação do coração. No entanto, ao diagnóstico molecular, nenhum dos 40 animais amostrados foi positivo à ranavirose. Tal resultado pode estar associado tanto a fatores intrínsecos (espécie, idade, resposta imune) como extrínsecos ao hospedeiro (alterações ambientais, patogenicidade viral). Em paralelo, em rãs de criação comercial, surtos por FV3 já foram detectados em vários ranários do país; contudo, essa é a primeira vez que uma prospecção para ranavirose é realizada especificamente com representantes da espécie Leptodactylus fuscus, em municípios da região centro-leste do estado de São Paulo. Assim, são necessárias mais pesquisas com espécies silvestres de rãs, particularmente no entorno de ranários com histórico de animais positivos para FV3, para melhor conhecimento da epidemiologia e dinâmica de transmissão da ranavirose entre rãs silvestres.The objective of this study was to investigate the occurrence of ranavirus infection caused by virus belonging to genus Ranavirus, Iridoviridiae family, in wild anuran amphibians from Porto Ferreira and Pirassununga municipalities, located in the central-eastern region of the state of São Paulo, Brazil, using molecular diagnostics. In all, 40 wild adult anurans of the species Leptodactylus fuscus were captured in the mentioned municipalities, and three target organs (liver, spleen and kidneys) of the viral replication were collected, being possible macroscopic changes in these organs recorded, and from which DNA was extracted. In the sequence, the polymerase chain reaction (PCR) was carried out using primers specific for the MCP (major capsid protein) gene of Frog Virus 3 (FV3), a circulating ranavirus in Brazil, with a FV3 isolate belonging to the biobank of the Laboratory of Zootechnical Hygiene of FZEA-USP employed as positive control and nuclease-free water as negative control. As a result, in relation to macroscopic alterations, only one specimen showed hepatosplenomegaly and heart hypopigmentation. However, for molecular diagnostics, none of the 40 animals sampled were positive for ranavirus. This result may be associated to both intrinsic (species, age, immune response) and extrinsic (environmental changes, viral pathogenicity) factors to the host. In parallel, FV3 outbreaks have already been detected in several frog farms in the country. However, this is the first time that a prospection for ranavirus infection is performed specifically with specimens of the Leptodactylus fuscus from municipalities in the central-eastern region of the state of São Paulo. Thus, more studies on wild-type frogs are needed, particularly in the settings of frog farms with positive animal history for FV3, to better understand the epidemiology and dynamics of ranavirus transmission among wild frogs.
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Gál, Julianna Mary. "Biomechanics of swimming in the frog, Hymenochirus boettgeri." Thesis, University of British Columbia, 1987. http://hdl.handle.net/2429/26258.
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Although frogs are recognized as accomplished swimmers, no detailed biomechanical study has been done. The hydrodynamics and mechanics of swimming, in the frog, Hymenochirus boettgeri, are investigated in this thesis. Hydrodynamic drag, of the body and splayed hind limbs of preserved H. boettgeri, was assessed by drop-tank experiments. Drag tests were also performed with the semi-terrestrial Rana pipiens. A comparison of their drag coefficients (CD) under dynamically similar conditions, suggests that jumping performance may not compromise the swimming ability of R. pipiens. Drag of the expanded foot of H. boettgeri, and acetate models thereof, was investigated by free fall drop-tank experiments, and a subtraction technique. The results of these methods and flow visualization experiments support the assumption that animal paddles can be treated as three dimensional flat plates, oriented normal to the direction of flow.
Cine films were used to study swimming during the near-vertical breathing excursions of H. boettgeri. The acceleration of frogs throughout hind limb extension (power stroke), is distinct from other drag-based paddlers (eg. angelfish and water boatman), which accelerate and decelerate within the power stroke phase. The propulsive force generated during the power stroke of a single sequence (sequence 1) is calculated from quasi-steady drag (static-body drag measurements, see Chapter I) and inertial considerations. Additional components of the forcebalance, including the net effect of gravity and buoyancy, and the longitudinal added mass forces associated with the frog's body, are integrated to establish upper and lower bounds of the propulsive force. The propulsive force remains positive throughout extension. The validity of using static drag estimates to describe dynamic resistance is explored.
Results from Chapter II suggest that simple drag-based models may not be sufficient to explain the swimming patterns observed. The right hind limb of the sequence 1 animal was modelled as a series of linked circular cylinders (the femur, tibiofibula, and metatarsal-phalangeal segments) and a flat plate (the foot). A blade-element approach was used to calculate the instantaneous drag-based and accelerative force components (parallel to the direction of motion) generated by hind limb flexion and extension. The negative thrust, generated by hind limb flexion, is probably responsible for the observed deceleration of the sequence 1 animal. Positive thrust is generated only during the initial stages of extension, almost exclusively by the feet. The impulse of the accelerative-based thrust far exceedes the impulse of the drag-based thrust. Negative thrust is initiated midway, and continues thoughout extension, despite the acceleration of the animal. Hind limb interaction, is thought to provide propulsive thrust for the latter half of the extension phase. A jet and/or ground effect may be involved. It is suggested that a combination of reactive, resistive and interactive forces are required to explain propulsion in H. boettgeri, and probably other anurans.Science, Faculty of
Zoology, Department of
Graduate
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Smith, D. R. "Studies on DNA sequences directing ribosomal transcription in Xenopus laevis." Thesis, University of Portsmouth, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.377704.
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Terry, Adrian Simon. "Studies on the biosynthesis of neuropeptides." Thesis, University of Cambridge, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.254521.
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Inczauskis, Heather Lynn. "The Need to Move: Exploring Landscape Connectivity through the Eyes of the Northern Leopard Frog." Thesis, North Dakota State University, 2017. https://hdl.handle.net/10365/28662.
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The northern leopard frog (Rana pipiens) is a species that depends on landscape connectivity to complete its lifecycle. However, due to historic and present anthropogenic landscape changes, this species encounters a variety of agriculture fields during migratory and dispersal movements. These landscape changes have potential to affect habitat connectivity for these frogs and may interfere with the species? life-cycle needs. Differing land-cover types have varying effects on movement, desiccation and predation of the northern leopard frog, which in turn affect the frog?s ability to survive. Through creation and use of an agent-based model that can simulate individual frog movement on a modeled landscape, I explored habitat connectivity in the prairie-pothole region. I used northern leopard frog movement and desiccation data collected from two summers of field work to inform my modeled scenarios. The model I developed allows for the exploration of habitat connectivity under various patterns of land-cover change.U.S. Geological Survey Climate Research and Development Program
North Dakota State University (NDSU)
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Xue, Yuan Zhen. "Isolation, structural characterisation and molecular cloning of novel polypeptides from frog venom." Thesis, University of Ulster, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.414990.
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Candido, Marcelo. "Aspectos celulares e moleculares da ranavirose experimental em tilápias do Nilo (Oreochromis niloticus)." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/74/74131/tde-14022019-154157/.
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Algumas doenças associadas à piscicultura de tilápias trazem enormes prejuízos aos criadores, resultando em expressivos coeficientes de morbidade e mortalidade entre animais de todas as idades. Nesse sentido, exigências para o aprimoramento do diagnóstico laboratorial de doenças de natureza infecto-contagiosa tornaram-se constantes, face às perdas vinculadas. Os Ranavirus são vírus que infectam vertebrados ectotérmicos causando necrose generalizada, hemorragias focais e apoptose celular nos animais infectados. O presente estudo objetivou a realização de infecções experimentais em larvas e alevinos de tilápia do Nilo (Oreochromis niloticus), através de 3 diferentes modelos de infecção, utilizando estirpe de Ranavirus Frog vírus 3-like; recentemente detectada e isolada no Brasil, para avaliação das patologias associadas, incluindo o sequenciamento e análise do genoma da cepa viral. Vários sinais clínicos macroscópicos e microscópicos foram observados, hemólise, hemácias com anisocitose e policromasia, alterações relacionadas a média dos volumes das hemácias e hemoglobina, índices hepato-somáticos e espleno-somáticos com interações estatisticamente significantes, linfócitos reativos, alterações nos níveis das enzimas alanina aminotransferase e corpúsculos de inclusão basofílicos em diferentes tecidos dos animais experimentados com Ranavirus FV3-like foram observados dentro do período de 60 dias pós-infecção. Além disso, animais experimentalmente infectados foram positivos ao Ranavirus através de qPCR. O genoma de cepa brasileira de Ranavirus FV3-like apresentou 105 kilobases, contendo 54,98% de guanina + citosina, sendo 94 potenciais ORFs anotadas. A reconstrução filogenética, baseada em sequencias nucleotídicas, agrupou a amostra brasileira de Ranavirus no clado dos Frog vírus 3-like e as maiores identidades do genoma se deram com cepas norte-americanas de FV3-like. Doze potenciais eventos de recombinação, estatisticamente significantes (p < 0,05), foram identificados entre a cepa brasileira e amostras de referência de Ranavirus FV3-like. Nesse sentido, o presente trabalho contribui para o melhor entendimento da infecção causada por estirpe brasileira de Ranavirus FV3-like em tilápias do Nilo (Oreochromis niloticus). Além disso, adiciona e reforça a potencial recombinação entre diferentes estirpes de Ranavirus, colaborando para uma melhor compreensão das características de agentes virais associados a graves surtos em vertebrados ectotérmicos no país.Some diseases associated with tilapia fish farming cause enormous losses to breeders, resulting in significant morbidity and mortality rates among animals of all ages. In this sense, requirements for the improvement of the laboratory diagnosis of diseases of infectious-contagious nature, became constant, in view of the related losses. Ranaviruses are viruses that infect ectothermal vertebrates causing widespread necrosis, focal haemorrhages and cell apoptosis in infected animals. The present study aimed to perform experimental infections in Nile tilapia (Oreochromis niloticus) fry and larvae through 3 different infection models, using Ranavirus Frog virus 3-like strain recently detected and isolated in Brazil, to evaluate the associated pathologies, including sequencing and genome analysis of the viral strain. Several macroscopic and microscopic clinical signs were observed, hemolysis, red blood cells presenting anisocytosis and polychromasia, alterations related to the mean red blood cell volumes and hemoglobin present in the red blood cells, hepato-somatic and spleno-somatic indexes showing statistically significant interactions, reactive lymphocytes, alterations in the levels of the enzymes alanine aminotransferase and basophilic inclusion corpuscles in different tissues of animals tested with Ranavirus FV3-like were observed within the 60-day post-infection period. In addition, experimentally infected animals were positive to Ranavirus through qPCR. The genome of the Ranavirus FV3-like Brazilian strain presented 105 kilobases, containing 54.98% of guanine + cytosine, with 94 potential ORFs annotated. The phylogenetic reconstruction, based on nucleotide sequences, grouped the Brazilian sample of Ranavirus in the clade of Frog virus 3-like, the greater identities of the genome were with North American strains of FV3-like. Twelve potential recombination events, statistically significant (p <0.05), were identified between the Brazilian strain and reference samples of Ranavirus FV3-like. The present work contributes to a better understanding of the infection caused by the Brazilian strain of Ranavirus FV3-like in Nile tilapia (Oreochromis niloticus). In addition, it adds and reinforces the potential recombination between different strains of Ranavirus, contributing to a better understanding of the characteristics of viral agents associated with severe outbreaks in ectothermic vertebrates.
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Schiller, Tamar Marie. "Urea production capacity in the wood frog (Rana sylvatica) varies with season and experimentally induced hyperuremia." Oxford, Ohio : Miami University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=miami1196441446.
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HOSHINO, TAKESHI, and TARUN K. BANERJEE. "ATP ase-Positive and Metallophilic Cells in the Skin of Frog, Rana Catesbeiana." Nagoya University School of Medicine, 1985. http://hdl.handle.net/2237/17481.
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