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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.
11

Culture methods for rat egg cylinders : improvement and evaluation

Van der Most, Renee Nathalie January 1993 (has links)
No description available.
12

The renin-angiotensin system and renal and endocrine function in the rat

Al-Barazanji, K. A. January 1987 (has links)
No description available.
13

Studies on the role of changes in the plasma levels of aromatic and branched-chain amino acids

Acworth, I. N. January 1986 (has links)
No description available.
14

Small mammals in disturbed tallgrass prairie landscapes

Moon, Derek January 1900 (has links)
Master of Science / Department of Biology / Jack Cully, Jr. / Disturbance is defined as any discrete event that disrupts ecosystem, community, or population structure and changes resources, substrate availability, or the physical environment. Habitat use by an organism is based on its perception of where to maximize its own fitness, and can be altered in response to disturbance-induced changes in resources, substrate, or physical features modified by disturbance. Disturbance-induced changes to vegetation structure reshape a small mammal’s surrounding physical environment and/or resources, and may influence its utilization of an area. Effective wildlife and resource management is dependent on a thorough understanding of how individual species and communities utilize their surroundings and how disturbance affects a species’ response to changes in its surroundings. We investigated seasonal habitat associations of three small mammal species and for overall species diversity across a gradient of military combat-vehicle disturbance intensities at the Fort Riley Military Reservation, Kansas. Deer mouse (Peromyscus maniculatus) abundance did not vary across a categorical gradient of disturbance created by military-combat vehicles, regardless of season. Western harvest mouse (Reithrodontomys megalotis) abundance was associated with more highly disturbed areas irrespective of season. Prairie vole (Microtus ochrogaster) abundance was associated with habitat that was less disturbed in the spring but more highly disturbed in the fall. Shannon diversity of the small mammal community was higher in the more highly disturbed areas regardless of season. This research shows that small mammals respond to disturbances created by military training with combat vehicles in a species-specific manner, and indicates that there may be differences in the effects of military training versus natural or agricultural disturbances on the abundance and diversity of small mammals. This is an important consideration given that the Department of Defense manages more than 12 million ha of land in the United States, and is charged under the Sikes Act with conserving natural resources on these lands, including biological diversity. Thus, the findings of other ecological research on the effects of disturbance on small mammals may not be directly applicable to the types of disturbances that occur on military lands, which underscores the need for further research on the specific effects of military-training activities on species’ responses.
15

Engaging professional mariners in marine mammal conservation

Thorpe, Leah Irene 16 May 2012 (has links)
Due to British Columbia‟s expansive coastline and limited funding for marine mammal conservation, research projects rely heavily on citizen scientists, or volunteers who contribute data. Professional mariners are an important target audience for such projects. In an attempt to increase participation by this sector, I designed a workshop using the Analysis, Design, Development, Implementation and Evaluation (ADDIE) process. I worked closely with four marine mammal conservation societies and conducted an analysis phase with the Canadian Coast Guard (CCG) using a combination of questionnaires and semi-structured interviews. I discovered that there is some awareness of existing conservation programs within the CCG but understanding of these programs as well as basic marine mammal knowledge and identification skills are limited. I also learned the importance of consistent feedback for continued participation and was able to relay information to the societies involved as well as use it to guide the development of my workshop.
16

Some aspects of the social and exploratory behaviour of laboratory rats and mice

Fraser, D. January 1972 (has links)
No description available.
17

Interactions between behavioural ecology and relatedness of female bottlenose dolphins in East Shark Bay, Western Australia

Frere, Celine Henria, Biological, Earth & Environmental Sciences, Faculty of Science, UNSW January 2009 (has links)
Female mammals play a central role in determination of social structure and are thus central to understanding the overall fission-fusion grouping pattern characteristic of many delphinid societies. Focusing specifically on female-female relatedness and association patterns, I have analysed more than 17 years of group composition, behavioural data, and genetic information to investigate complex interactions between behavioural ecology and relatedness and to also examine the common social evolutionary theory, that variation in mammalian social systems is typically attributed to five main factors: inclusive fitness, predation pressure, sexual conflict and male harassment, inbreeding avoidance, and resource competition. Overall, I found that female bottlenose dolphin association patterns depend upon the interplay between matrilineal kinship, biparental relatedness and home range overlap, and that female bottlenose dolphins seem to adapt their social strategies to seasonal variation in levels of predation and male harassment. The presence of both high sexual conflict and bisexual philopatry lead me to investigate the extent of inbreeding avoidance. I found that more than 14% of the calves were most likely the product of mating between close relatives, and identified female fitness costs to inbreeding. We were able to show that the effect of inbreeding on females??? fitness occurs via two independent mechanisms: being inbred and having at least one inbred calf. Inbred calves are on average weaned later than non-inbred calves, and a female???s first calf has a higher probability to be an inbred than subsequent calves. Last, I examined whether sociality provides inclusive fitness to female bottlenose dolphins through an investigation of both the additive genetic and social variance components of female calving success using a pedigree-free animal model. I found that variance in calving success of female bottlenose dolphins is best explained by complex genetic and social interactions. Females with high calving success showed both high genetic and social merit; they not only have good genes but also prefer to associate with others of high fitness. This study reveals that both social and heritable genetic variance contribute to fitness trait variance in the wild.
18

Populations of small mammals and their utilization of arthropods on Ohio strip-mined lands /

McGowan, Kevin J. January 1900 (has links)
Thesis (M.S.)--Ohio State University. / Includes bibliographical references (leaves 64-76). Available online via OhioLINK's ETD Center.
19

Spatial variation in small mammal communities across the Karoo Shale Gas Development Area of South Africa

Nadine, Aboul-Hassan 01 April 2021 (has links)
This study details results of small mammal surveys at 24 sites in four biomes (Nama- and Succulent Karoo, Albany Thicket, Grassland) as part of the Karoo BioGaps project to augment baseline biodiversity information needed to guide proposed fracking activities in the Shale Gas Development Area (SGDA) (Holness et al. 2016). A strategic Environmental Assessment (SEA), commissioned by the South African Government, evaluated the potential to exploit the supposedly substantial reserves of shale gas using hydraulic fracturing (“fracking”) in the Great Karoo Basin of South Africa. Terrestrial micromammals (<500g) were captured using Sherman livetraps (September 2016 to March 2017). Sampling over 6580 trap-nights produced 339 captures of 271 individuals representing 14 taxa. Trapping success was low 5.14% (mean per site 0.37± 0.61%). Most captures (87%) and individuals (83%) were recorded in the Nama-Karoo (294 captures, 226 individuals, 15 sites), whereas only 5 captures were recorded in Albany Thicket (3 sites). Four xerophilous/generalist species (Micaelamys spp. (Rock rats), Gerbilluscus paeba (Hairyfooted Gerbil), Macroscelides proboscideus (Round-eared Sengi), and Elephantulus spp. were numerically dominant at most sites, and within most biomes/bioregions; while five rare species were only ever recorded once. Mean α diversity (observed species richness Sobs) per site (2.88 ±1.99) and Shannon-Wiener diversity (1.70 overall, 1.04 ±0.33 per site) were low, with only 5.47 effective species (mean = 3.04 ±1.08 per site) and low equitability (0.64 overall). Sobs was highest in Nama-Karoo (13 species), and lowest in the Grassland and Albany Thicket biomes (2-5 species). Species accumulation/rarefaction curves did not reach asymptotes, and Sobs values for most sites/biomes/bioregions were significantly lower than Chao1 predicted species richness, suggesting that sampling effort did not accurately estimate species richness. However, trapping efficiency was generally high (56-100%; mean 86.7%) which compares favourably with that of two recent published studies in South Africa. Multiplicative beta diversity (βMt) across the SGDA was 4.56 indicating high species turnover between sites/biomes/bioregions. Species turnover was high across biome boundaries, notably Albany Thicket-Grassland (15), Nama-Karoo-Albany Thicket (14), and Succulent Karoo-Grassland (12). Biomes and bioregions tended to plot apart in ordination analyses with relatively low (40-60%) Sorenson similarity, indicating that most regional small mammal communities were well-differentiated. Despite data limitations, 66 new distribution records for 21 sites are reported for the SGDA. Total species richness (including historical records) was highest in the Nama-Karoo (19), particularly the Upper Karoo bioregion (19, mean 6.45 ±2.16, 11 sites), followed by the Grassland (16), and Albany Thicket (5) biomes. Total species richness records for most sites/regions fell within the iChao2 CI bounds, thus integrating trapping and historical records provided a relatively robust data set for subsequent spatial diversity analyses. However, even the total species richness dataset is likely to underestimate true diversity owing to not sampling arboreal species or detecting some cryptic species. Generalized linear analyses indicated that small mammal diversity indices were significantly associated with certain environmental/climatic parameters (livestock, drought). Despite the west to east increase in precipitation, highest diversity was concentrated in the arid north-west Nama-Karoo where dwarf shrubs and succulents predominate. This suggests that environmental and niche filtering are significant proximate factors shaping small mammal assemblages. No significant effects of biotic interactions (particularly competition following Diamond's (1975) first two rules) or resource-mediated niche limitations were evident for SGDA species assemblages. However, results for the Nama-Karoo (i.e. for a natural phytogeographical rather than geoeconomically-defined area) were significant suggesting that biotic interactions may also be proximate factors shaping local assemblages. Site assemblages were significantly nested, indicating that species at species-poor sites were subsets of those at richer sites; and thus, that site communities may have been structured by either long-term (ultimate) regional biogeographic processes (e.g. immigration and extinction related to distances between sites) or habitat filtering operating at local scales. Data deficiencies notwithstanding, my results present the most comprehensive landscape-level analysis for small mammals, and the only baseline dataset (based on randomized sampling) for the Greater Karoo and SGDA. While my results must be treated with caution, I am confident that the recommendations I make on species, sites and regions potentially vulnerable will be a useful guide to possible impacts of fracking in the study area.
20

Occurrence of Invasive Mammals and Native Carnivores in Northern Patagonia

Gantchoff, Mariela Gisele 15 August 2014 (has links)
The study of biological invasions is important to management and conservation. I assessed the occurrence of invasive mammals and native mesocarnivores in northern Patagonia. Invasive species had varying responses to anthropogenic disturbance, and were differentially influenced by environmental and anthropogenic factors. Invasive species were also a substantial part of native mesocarnivores diets and appeared to influence their temporal activity, but not occupancy. Overall, I observed high spatial and temporal overlap between native carnivores and coexistence seemed facilitated by diet. Humans had both a positive and negative influence in this community, being responsible for the introduction of invasive species and possibly further facilitating their expansion, while also limiting other invasive species and potentially benefiting native species directly and indirectly. Undoubtedly, biological invasions, anthropogenic disturbance, and native communities can present complex interactions which will require further study to provide effective tools for protected areas.

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