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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Characterizing softball bat modifications and their resulting performance effects

Cruz, Curtis Matthew, January 2005 (has links) (PDF)
Thesis (M.S. in mechanical engineering)--Washington State University. / Includes bibliographical references.
72

Observations on the morphology and biology of Longibucca eptesica n. sp. (Nematoda: Cylindrocorporidae) parasitic in the bat

Elsea, John Robert, January 1953 (has links)
Thesis--Catholic University of America. / Reprinted from the proceedings of the Helminthological Society of Washington, v.20, no. 2, July, 1953. "Literature cited": p. 76.
73

The influence of posture and brain size on foramen magnum position in bats

Ruth, Aidan Alifair. January 2010 (has links)
Thesis (M.A.)--Kent State University, 2010. / Title from PDF t.p. (viewed Apr. 28, 2010). Advisor: C. Owen Lovejoy. Keywords: foramen magnum; human evolution; locomotion; bats. Includes bibliographical references (p. 36-42).
74

Variation in life history traits in the little brown bat, Myotis lucifugus (chiroptera: vespertilionidae)

Reynolds, D. Scott January 1999 (has links)
Thesis (Ph.D.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / This thesis examines the intrinsic and extrinsic factors that influence the reproductive strategy of a temperate insectivorous bat, Myotis lucifugus. Body composition was measured using both direct analysis (dehydration and fat extraction) and total body electrical conductivity (TOBEC) analysis. Changes in body composition during the reproductive season show that both fat and mineral stores are mobilized during lactation. However, the changes were small relative to the level of reproductive effort supporting the hypothesis that small insectivorous bats use direct-costing to meet the costs of reproduction. An increase in size of the digestive tract suggests that increased foraging capacity is an important component of this strategy. Changes in body composition in young bats show a two-week period of linear postnatal growth followed by a rapid transition to adult body composition. By the end of August, young bats had achieved a mass-specific body composition similar to post-lactating adult females, although they had a smaller body mass. Body composition did not influence any of the reproductive traits investigated in the present study. Young bats born early in the parturition period had a higher postnatal growth rate, suggesting that time-dependent effects influence reproductive strategy in Myotis lucifugus. Sex-dependent influences suggest that maternal costs are higher when producing female young: female offspring 1) had a higher postnatal growth rate, 2) had more body fat at weaning, 3) were born earlier and remained with the mother longer than male offspring. High levels of precipitation during early pregnancy resulted in a delayed parturition period and a male-biased sex-ratio at birth. High levels of precipitation in late summer increased overwinter recapture rate in adult females. Low ambient temperature in early summer reduced the reproductive rate and level of reproductive synchrony. Low temperatures in late summer reduced overwinter recapture rate in yearling bats. These extrinsiv factors may influence the energy budget of M. lucifugus by increasing thermoregulatory costs and reducing foraging opportunity or prey availability. Thus intrinsic factors influenced some of the within-season variation in reproductive traits, whereas extrinsic factors primarily affected between-year variation. / 2031-01-02
75

Variation in Habitat Use and its Consequences for Mercury Exposure in Eastern Ontario Bats (Myotis lucifugus and Eptesicus fuscus)

Bedard, Bailey 03 March 2022 (has links)
Insectivorous bats have been found to have unusually high levels of mercury. While broad geographic scale studies have investigated factors contributing to mercury bioaccumulation in bats across Canada, studies investigating differences in regional scale bioaccumulation and the contributing factors remain scarce. Here, I comprehensively investigate the bioaccumulation of mercury in two insectivorous bats, the big brown bat (Eptesicus fuscus) and the little brown bat (Myotis lucifugus), collected over a period of ~20 years along the St. Lawrence River in Eastern Ontario, parts of which are historical hotspots of mercury, to address two objectives: First the determination of biological and environmental factors, including dietary sources, contributing to reported patterns of fur total mercury bioaccumulation, and second the investigation of DNA-based biomarkers as potential tools to assess internal tissue-responsiveness to mercury exposure, specifically global DNA methylation and expression levels of mitochondrial DNA. With regard to factors determining fur total mercury concentration in Eastern Ontario bats, significant differences between species exist, as higher concentrations were found in big brown bats compared to little brown bats. Sex contributed to differences in fur total mercury, however in a species-specific manner. Male fur contained higher total mercury concentrations compared to females in big brown bats, but not little brown bats. Female reproductive status differentially affected fur mercury concentrations between both species, reducing concentrations in pregnant little brown bats, while significantly increasing concentrations during lactation in big brown bats. Finally, fur total mercury concentration in adults was higher than that of juvenile bats (< 1 yr). To address the hypothesis that aquatic emerging and terrestrial insect diets differentially contribute to Eastern Ontario bat mercury concentration, I used stable isotope analysis and telemetry approaches and caught aquatic and terrestrial insects. While higher total mercury was identified in aquatic compared to terrestrial insects, a high degree of variability in the isotope signature in insects and bats in Eastern Ontario did not allow to fully address this hypothesis. However, data pointed to a more specialized diet in big brown bats compared to a more generalist diet in little brown bats as well as a sex-specific correlation between dietary source and fur total mercury concentration in little and big brown bats. The evaluation of potential epigenetic and mitochondrial DNA-level molecular biomarkers in kidney, brain and liver (DNA methylation and assessment of relative mitochondrial DNA copy number) did not reveal significant correlations with fur total mercury concentrations. This may suggest that the mercury concentrations measured in this study were not high enough to elicit these specific DNA level responses or they do not represent relevant biomarkers of environmental methylmercury exposure, at least in big brown bats. Overall, this thesis contributes to our understanding of regional variability in fur total mercury concentration within and between Eastern Ontario bat species. These findings provide important insights for future targeted investigations of the contribution of aquatic emerging and terrestrial insect dietary sources on the one hand and underline the importance of accounting for regional variability in more global scale comparisons of bat mercury bioaccumulation on the other.
76

Use of Highway Culverts, Box Bridges, and Caves by Winter-Roosting Bats in Mississippi

Katzenmeyer, Jessica B 07 May 2016 (has links)
White-nose Syndrome (WNS) has caused declines in bat populations in many areas of North America. To understand bat use and fungus presence in caves and culverts in Mississippi, I recorded bat species and abundance in these sites, roosting site characteristics, and incidence of WNS in selected caves and culverts used by bats. Sixteen caves and 214 culverts were surveyed from November-March 2010-2015. Five bat species were detected, and tricolor bats (Perimyotis subflavus) and southeastern myotis (Myotis austroriparius) were most abundant. Over five years, 3,789 roosting bats were recorded in caves and 16,812 were detected in culverts. I found significant relationships between bat numbers in culverts and microclimate conditions, dimensions, and proximity to public lands (P < 0.03). This study can help biologists with prioritization of protection and monitoring of culvert and cave roost sites and provide a greater understanding WNS incidence in these sites.
77

Biodiversity and dynamics of direction finding accuracy in bat biosonar

Uzair Gilani, Syed 04 April 2016 (has links)
In the biosonar systems of bats, emitted acoustic energy and receiver sensitivity are distributed over direction and frequency through beampattern functions that have diverse and often complicated geometries. This complexity could be used by the animals to determine the direction of incoming sounds based on spectral signatures. The present study in its first part has investigated how well bat biosonar beampatterns are suited for direction finding using a measure of the smallest estimator variance that is possible for a given direction (Cram{'e}r-Rao lower bound, CRLB). CRLB values were estimated for numerical beampattern estimates derived from 330 individual shape samples, 157 noseleaves (used for emission) and 173 outer ears (pinnae). At an assumed unit[60]{dB} signal-to-noise ratio, the average value of the CRLB was 3.9textdegree, which is similar to previous behavioral findings. Distribution for the CRLBs in individual beampatterns were found to have a positive skew indicating the existence of regions where a given beampattern does not support a high accuracy. The highest supported accuracies were for direction finding in elevation (with the exception of phyllostomid emission patterns). Beampatterns in the dataset were also characterized based upon the differences in the type of acoustic signal they are associated with, the functionality of the baffle shape producing them and their phylogeny. In the second part of the study, functionality of various local shape features was investigated under static and dynamic conditions. Each local shape feature was found to have an impact on the estimation performance of the baffle shape. Interaction of the local shape features among themselves as well as their dynamic motion produced a plethora of results, not achievable through either single features or through their static states only. / Ph. D.
78

A comparative ecological study of insectivorous bats (Hipposideridae, Vespertilionidae and Rhinolophidae) in Hong Kong, with specialreference to dietary seasonality

Ades, Gary William John. January 1994 (has links)
published_or_final_version / Ecology and Biodiversity / Doctoral / Doctor of Philosophy
79

Genetic variability of Chaerephon atsinanana (Chiroptera) within the context of the Afro-Malagasy Molossidae : a mitochondrial and nuclear perspective.

Napier, Melanie Carmel. 25 November 2013 (has links)
This study has focused on genetic variability and structure in Chaerephon atsinanana, a newly-described molossid bat found in the mid to southern region of the eastern watershed of Madagascar. As these bats are strong fliers, and are able to traverse the riverine and mountain barriers within the landscape, it was hypothesized that they would show relatively low levels of intraspecific genetic structure, consistent with patterns shown for other Molossidae on Madagascar (Mormopterus jugularis, Mops midas, Mops leucostigma, and C. lecuogaster. Phylogenetic (neighbor-joining, parsimony and Bayesian inference) and population genetic analyses of maternally-inherited mitochondrial control region sequences revealed the presence of 6 distinct haplotype groups separated by genetic distances of up to 8.14% (mean 4.95%). There were high levels of genetic structure among the haplotype groups (overall FST= 0.994). Thus the hypothesis of low levels of genetic structure was rejected. Bayesian skyline analyses and significantly ragged mismatch distributions were consistent with ancient stable C. atsinanana populations which were of constant size during the last two major Pleistocene glacial periods. This made retreat into and expansion from glacial refugia an unlikely explanation for such high levels of structure. An alternative hypothesis is that C. atsinanana haplotype groups are spatially structured as a result of philopatry. As mitochondria are maternally-inherited, this data is consistent with the existence of female philopatry in C. atsinanana. The second aim of this study was to examine the genetic structure of C. atsinanana with nuclear sequence markers, which are biparentally-inherited, in order to provide information on the male contribution to gene flow and the possible presence of male philopatry in this molossid bat species. The initial objective was to amplify and sequence candidate nuclear markers in order to identify those which were variable among C. atsinanana samples. I attempted to amplify and sequence a set of 12 nuclear markers, identified from the literature, which had been reported to show high levels of variability, or which were untested and showed the potential for high levels of variability. Of these, the intron markers PNPO-3, SLC38A7-8, CARHSP1-1, GAD2-1, OSTA-5 had not previously been used in phylogenetic analyses while FES, GHR, RHO1 CHRNA1, STAT5, PRKC1 and THY had been. I was not able to amplify and/or sequence SLC38A7-8, CARHSP1-1, GAD2-1, OSTA-5, CHRNA1, STAT5 and THY across the range of the C. atsinanana samples. PNPO-3, FES, GHR, RHO1 and PRKC1were successfully amplified and sequenced, but showed no variability and very little polymorphism, and were therefore unsuitable for testing hypotheses related to genetic variability of C. atsinanana populations. These five nuclear sequence markers were further used to investigate phylogenetic relationships among 5 genera (Chaerephon, Mops, Mormopterus, Otomops and Sauromys) and 13 species of Afro-Malagasy molossid bats, and to provide a nuclear phylogenetic perspective on the newly-described C. atsinanana. PNPO-3 is a novel nuclear intron marker, previously unused in phylogenetic studies. This intron provides resolution primarily at the genus level, and is less informative at interspecific level. These five nuclear markers were combined with already existing mitochondrial cytochrome b (Cyt b) and nuclear Rag2 data retrieved from GenBank. This study provides strong support for the monophyly of the Chaerephon and Mops taxa included, with the exception of C. jobimena, which was weakly associated with this group. There was no support for the generic affiliation of C. jobimena or for the monophyly of either of the genera Chaerephon or Mops individually. This leads to the suggestion that Mops and Chaerephon be combined into a single genus, with crown age of 14.82 (6.44-25.54) MYA, or 21.97 (12.16-33.44) MYA if C. jobimena is included. Otomops forms a strongly supported clade consistent with its generic status, comprising two subclades corresponding to the recognised sister species O. martiensseni and O. madagascariensis, which last shared a common ancestor 8.35 (2.87-17.47) MYA. This study provides good nuclear support for the mitochondrially-defined subclades of O. martiensseni, which last shared a common ancestor 4.18 (1.08-9.96) MYA. It would appear appropriate to name the clade from north east Africa and Arabia as a new species of Otomops, as the clade from southern and western Africa includes the type locality. This study provides weak support based on individual gene regions for associations of Sauromys with Otomops and Mormopterus, although these do not stand up in the concatenated datasets which offer better resolving power, indicating that Sauromys is not phylogenetically associated with Chaerephon/Mops, Otomops and Mormopterus. These results provide some support for the membership of Mormopterus in the proposed Old World Molossid tribe, Tadarini, but also support Mormopterus as a basal genus within the Molossidae, consistent with its designation as a separate tribe, Mormopterini. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2013.
80

Genetic analysis of Chaerephon pumilus (Chiroptera: Molossidae) from southern Africa.

January 2008 (has links)
Chaerephon pumilus, the little free-tailed bat, (family: Molossidae) has a distribution throughout most of sub-Saharan Africa and the eastern region of Madagascar. The vast geographical distribution of this species is accompanied by considerable phenotypic variation, which may conceal cryptic species. The cytochrome b (845 nucleotides) and D-loop (314 nucleotides) regions of the mitochondrial DNA were sequenced to assess phylogenetic relationships within C. pumilus (southern Africa) and in relation to Chaerephon species from Madagascar (C. pumilus, C. leucogaster). Samples were obtained from KwaZulu-Natal, South Africa, and localities in Swaziland. The cytochrome b sample (n = 11) comprised four haplotypes, with a haplotype diversity of 0.6727, whilst the D-loop (n = 34) dataset comprised 13 haplotypes with a haplotype diversity of 0.8342. Neighbour joining, maximum parsimony and Bayesian analyses revealed congruent tree structures for both mtDNA regions. All Chaerephon taxa in this study formed a monophyletic clade with respect to the outgroup Mops midas. Chaerephon pumilus from the eastern side of Madagascar formed a well-supported monophyletic group, sister to a clade comprising C. pumilus (southern Africa) and C. leucogaster, and is suggested to comprise a separate species. Southern African C. pumilus formed two paraphyletic clades, A and B, separated by a genetic distance of 0.9 %. Chaerephon leucogaster formed a monophyletic group nested within southern African C. pumilus, suggesting conspecificity. However, the well-characterized morphology of C. leucogaster lends support to its specific status, and suggests the possible existence of cryptic species among southern African C. pumilus. Population genetic analysis suggests that two C. pumilus (southern African) clades have been expanding, one for between 2432 and 4639 years, and the other for the 11156 to 21280 years. A combined cytochrome b analysis, trimmed to 343 nucleotides, was carried out on the data from this study and that of Jacobs et al. (2004), also on southern African C. pumilus. Haplotypes from the Jacobs et al. (2004) study, which also identified two 0.9 % divergent clades (light- and dark-winged) were found to be identical or very similar to haplotypes from this study and were interspersed among southern African C. pumilus haplotypes in phylogenetic analyses. Chaerephon pumilus haplotypes from Zambia and Tanzania were found to be more closely related to those from southern Africa and to C. leucogaster than to C. pumilus (Madagascar), further indicating that this may be a separate species. Haplotypes from the light-winged clade of Jacobs et al. (2004) were identical to those of dark-winged samples from this study, suggesting that wing shade may not be diagnostic of the two clades. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2008.

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