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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.
121

A eletroforese capilar para a separação das metalotioneínas da cianobactéria (Synechococcus PCC 7942) e de mamíferos / Capillary electrophoresis for the separation of cyanobacterial metallothionein (Synechococcus PCC 7942) and mammals

Ana Clara Felix Vida 23 March 2011 (has links)
Metalotioneínas (MTs) são proteínas de baixa massa molecular, que tem como principal função a regulação dos níveis de metais nos organismos. A caracterização das MTs da cianobactéria Synechococcus PCC 7942 por eletroforese capilar foi feita em comparação com os padrões comerciais de MTs de rim de cavalo e de fígado de coelho. As MTs de mamíferos apresentam diferentes arranjos moleculares, classificadas em isoformas. Na aplicação da eletroforese capilar como metodologia analítica para a otimização da separação das isoformas existentes, foram investigados a influência da composição da solução eletrolítica, variações da voltagem, comprimento do capilar e diâmetro interno do capilar. Os perfis eletroforéticos das misturas das MTs purificadas a partir de rim de cavalo e fígado de coelho comparados com a de cianobactéria mostraram uma diferenciação no tempo de migração. Para a separação foram testados eletrólitos tais como fosfato, borato e TRIS-HCl, sendo que os melhores resultados foram obtidos com o tampão TRIS-HCl (70 mM, pH 8,2) com adição de 5% de metanol. A separação eletroforética foi testada em capilares de sílica fundida de 75 e 25 m d.i., comprimento de 40, 50 e 60 cm. As soluções das amostras em volume de 327 nL foram introduzidas por injeção hidrodinâmica. As diferenças de potencial testadas foram de 10, 15, 20 e 25 kV. As melhores condições de separação foram atingidas empregado TRIS-HCl com 5% metanol como solução eletrolítica, em capilar de 60 cm e diferença de potencial de 20 kV o que estabilizou a corrente de separação em 42 \'mü\'A. Os resultados mostraram que a eletroforese capilar mostrou-se eficiente para separação das MTs de mamifero e da Synechococcus devido às diferenças de carga e tamanho das moléculas / Metallothioneins (MTs) are low molecular weight proteins, which main functions are the regulation of metals levels in the body and detoxification. The capillary electrophoresis (CE) characterization of MT from Synechococcus cyanobacteria was attained by comparison with commercial standards of horse kidney and rabbit liver MTs. The influence of electrolyte, such as phosphate, borate and TRIS-HCl buffers on the separation performance were tested. Also, parameters such as voltage potential, capillary length and capillary inner diameter were investigated to attain optimized separation of mammal and Synechococcus MTs. The electrophoretic profiles of MTs revealed four abundant metallothionein isoforms for the horse kidney sample, one for rabbit liver MTII and two for cyanobacteria Synechococcus. The separation by CE of horse and cyanobacteria MTs mixtures differentiated two sets of signals, the first with four peaks corresponding to the horse sample and the last to Synechococcus. The mixture of rabbit liver MT and cyanobacteria MTs presented a first peak for rabbit MTII and a second for cyanobacteria. Tests were performed trying phosphate, borate and TRIS-HCl buffers, however the best results were attained with TRIS-HCl buffer (70 mM, pH 8.2) with addition of 5% methanol. Different capillary lengths of 40, 50 and 60 cm and two internal diameters of 75 and 25m were tested. Also, voltages of 10, 15, 20 and 25 kV were studied. The best experimental conditions were attained using a 60 cm long capillary, TRIS-HCl plus 5% methanol as electrolyte, the application of 20 kV which allowed maintaining a separation current of 42 \'mü\'A. Results demonstrated that capillary electrophoresis was efficient for separation of MTs of mammals from that of Synechoccocus due their differences on size to charge
122

Scaling of Animal Communities: From Local and Landscape to Global Processes

Udy, Kristy 11 July 2017 (has links)
No description available.
123

Mass Cetacean Strandings in the United States- Comparison of Northeast and Southeast Strandings, 1997-2011

Friedman, Brielle 13 May 2013 (has links)
Marine mammal mass strandings have been documented for centuries, even going as far back as Aristotle. For just as long, the causes of these mass strandings have been questioned. With every species of cetacean known to have stranded, it is important to find trends to understand and prevent these strandings from occurring. With a heightened awareness of this issue, leading to the creation of marine mammal stranding networks throughout the United States in the 1990s, a more comprehensive approach to data collection has helped with the study. Issues such as seasonality, weather, topography, and disease have all been observed as a potential cause of these events. This study attempted to look at the Atlantic Coast of the United States, and its documented mass strandings from 1997-2011. Stranding data taken from the Northeast and Southeast US Marine Mammal stranding network database provided a basis for the study of these mass strandings. Many of the possible causes of these strandings, including seasonality, location, and species were studied. There was some correlation found between seasons and stranding, meaning there are certain times of the year when a cetacean pod may be more likely to strand.
124

Levels of Polycyclic Aromatic Hydrocarbons Archived Subcutaneous Blubber Samples in the Florida Manatee (Trichechus manatus latirostris)

Bigelow, Melinda Michelle 01 August 2006 (has links)
Polycyclic aromatic hydrocarbons (PAH) have been linked to cancer in humans. Subsequently, 16 of them were listed as priority pollutants by the Environmental Protection Agency in the Clean Water Act. The Florida manatee (Trichechus manatus latirostris) is an herbivorous endangered species that could have the potential to accumulate these compounds. The waters they inhabit have been shown to have PAH concentrations in the sediment from 0.035 μg/g w.w. (wet weight) to 0.686 μg/g w.w. PAH bioaccumulate due to their lipophilic nature and the manatee has a thick blubber layer that may allow for the accumulation of these compounds. Forty-eight archived subcutaneous manatee blubber samples were collected from Florida Fish and Wildlife Conservation Commission Marine Mammal Pathobiology lab and analyzed for 16 known priority pollutant PAH. Samples were then compared to a standard using HPLC analysis. Concentrations were found to range from 0.001 μg/g w.w. to 84.84 μg/g w.w. All 16 priority pollutant PAH were found, however not all 16 were found in any one animal. Forty-six of forty-eight manatee samples analyzed were found to have at least one form of PAH. The number of occurrences of each PAH out of 48 samples ranged from 1-19. The highest average PAH concentration was acenaphthylene with 12.60 μg/g w.w. There was no significant difference (p-value >0.10) between total, carcinogenic and noncarcinogenic PAH, with levels of 2.01 μg/g w.w., 2.18 μg/g w.w. and 1.84 μg/g w.w. respectively. No significant difference (p-value >0.10) was found between year or location of carcass recovery as well as sex of manatee. Averages ranged between 0.02 μg/g w.w. and 18.92 μg/g w.w. for year and 0.15 μg/g w.w. and 5.68 μg/g w.w. for location. Male average levels were 5.21 μg/g w.w., while female averages and perinatal averages were 1.51 μg/g w.w. and 1.147 μg/g w.w. respectively.
125

Studies of the ecology of the East African buffalo

Sinclair, Anthony Ronald Entrican January 1970 (has links)
No description available.
126

Oceanography and underwater acoustics in Resolute Bay, Nunavut: 2012-2015

O'Neill, Caitlin 12 July 2016 (has links)
Resolute Bay, a remote Arctic bay opening into Parry Channel, in the Canadian Arctic Archipelago, hosts diverse populations of marine mammals and fish at various times each year. These animals migrate through the bay following patterns linked to food availability and oceanographic conditions; however, these patterns are not well understood. The focus of this study was to measure the oceanographic properties of the waters in and around Resolute Bay and to record underwater sounds to obtain marine mammal temporal patterns and ambient sound levels. Results showed the water properties in Resolute Bay differed from the waters outside of the bay. Dissolved oxygen saturation levels in Resolute Bay decreased during ice-covered times, with lowest levels between May and July. Dissolved oxygen was replenished after the ice left the bay. Sudden changes in salinity, temperature, and dissolved oxygen were observed in Resolute Bay when outside waters entered. Mean third-octave band sound pressure levels were 85.3 dB re 1 μPa during high ice concentration, and 95.6 dB re 1 μPa during ice-free and freeze-up periods, and reached a maximum of 145.3 dB re 1 μPa when vessels were present. Belugas (Delphinapterus leucas) and narwhals (Monodon monocero) were only present in periods of low ice concentration, while bearded seals (Erignathus barbatus) and ringed seals (Pusa hispida) remained throughout the entire year. / Graduate / 2018-07-01
127

The Distribution and Population Dynamics of the Golden Mouse (<em>Ochrotomys nuttalli</em>) at Its Southern Range Periphery

Smiley, Sarah A 22 February 2010 (has links)
This research assesses the status of the golden mouse (Ochrotomys nuttalli) in Florida by taking a multi-pronged approach. Geographic Information Systems (GIS) was used to understand the distribution of habitats and occurrence records for this species within the state. Presence-absence trapping occurred at 13 study sites to determine if historic southern periphery populations were still occupied, gauge if more central populations were being maintained, and document golden mice in previously unrecorded areas. In addition, surveys for O. nuttalli took place at regular intervals at the USF Ecological Research Area to understand how populations of this species fluctuate over time and ensure that individuals could be caught during the months when statewide trapping was occurring. Trapping data from all 14 sites were combined to determine a level of confidence for absences at each site which did not yield a golden mouse capture. Finally, I determined the relative abundance of golden mice relative to other small mammal species caught. Locality records for this species align closely with the distribution of hardwood-containing habitats in Florida. The distribution of O. nuttalli is not continuous across Florida and becomes increasingly patchy near the southern range periphery of this species. In south-central Florida, populations are restricted to regions where hardwoods extend south along one of three upland ridges. Golden mice were determined to be present in the vicinity of the southernmost historic sites on each of these ridges. Ochrotomys nuttalli were captured at six of the 13 sites surveyed. At the USF Ecological Research Area, O. nuttalli were captured in all months surveyed although abundances remained relatively low from October through January and then increased from February through May. At study sites which did not catch a golden mouse, 78.6 to 100% of the trapping periods which successfully caught a golden mouse had done so by the effort levels invested at these absent sites. Ochrotomys nuttalli was the fourth most abundant of 12 species captured, but several of the species caught less frequently than golden mice are non-native or too large to have their true abundance reflected by these trapping methods.
128

Inovační metody provádění biologické ochrany letišť / Innovative methods of airport biological control

Bulíček, Pavel January 2010 (has links)
The main content of this master’s thesis is identification of biological threats and analysis of present means of aerodrome biological control, description of their effectiveness and possibilities of usage. Furthermore the way of bird strikes recordkeeping and innovative means, devices and procedures of aerodrome biological control considering the required safety level are mentioned.
129

Evolution and paleoecology of Pliocene Suidae (Artiodactyla, Mammalia) in the lower Awash Valley (Afar, Ethiopia): implications for hominin evolution and paleoenvironments

January 2018 (has links)
abstract: Providing an environmental context to early hominins is as important as describing the hominin fossils themselves, because evolutionary processes are tightly linked to everchanging ecosystems that vary across space and through time. An optimal understanding of ecosystems changes is critical to formulate and test hypotheses regarding human evolution and adaptation. Fortunately, the fossil record has yielded abundant remains of mammals which can be used to explore the possible causal relationships between environmental change and mammal – including hominin –evolution. Although many studies have already been conducted on this topic, most of them are framed at large spatial and temporal scales. Instead, this dissertation focuses on the evolution and paleoecology of only one group of mammals (the Suidae) in a specific geographical area (lower Awash Valley in Ethiopia) and within a constrained time frame (3.8–2.6 Ma). Three dissertation papers address: 1) changes in suid taxonomic composition in relation to Late Pliocene faunal turnover ~2.8 Ma in the Lee-Adoyta basin, Ledi-Geraru; 2) comparisons of suid diets from Hadar (~3.45–2.95 Ma) with respect to those of Kanapoi (~4.1 Ma, West Turkana, Kenya); 3) the dietary ecology of the suids from Woranso-Mille (~3.8–3.2 Ma). Results of these papers show that 1) after ~2.8 Ma there is a replacement of suid species that is coupled with low relative abundance of suids. This is compatible with more open and/or arid environments at this time; 2) suid dietary breadth was broader in Hadar than in Kanapoi, but this is mostly driven by the dietary niche space occupied by Kolpochoerus in Hadar, a suid genus absent from Kanapoi; 3) suid diets vary both temporally and geographically within the lower Awash Valley. Kolpochoerus incorporates more C4 resources (e.g., grasses) in its diet after ~3.5 Ma and in general, suids after ~3.5 Ma in Woranso-Mille had C4-enriched diets in comparison with those from nearby Hadar and Dikika. Presumably, the changes in suid communities (relative abundance and taxonomic composition) and dietary shifts observed in suids were triggered by climatic and habitat changes that also contributed to shape the behavioural and morphological evolution of early hominins. / Dissertation/Thesis / Doctoral Dissertation Anthropology 2018
130

The Mammalian Geochronology and Biogeography of Paşalar (Middle Miocene, Turkey)

Bernor, Raymond L., Tobien, Heinz 01 January 1990 (has links)
The Paşalar fauna includes 56 mammalian species of European. Asian, African and North American origin. Evidence provided on the stage-of-evolution of the primates Sivapithecus darwini and cf. Kenyapithecus, the rodent Turkomys pasalarensis, insectivores, carnivores, rhinos, suids and ruminants suggests that Paşalar is correlative with the Late Langhian marine stage and European Mammal Neogene Zone 6., circa 15 Ma (million years ago). A review of the Paşalar fauna's biogeographic history suggests that it was aggregated by a succession of pulsed intercontinental geographic extensions tied to global sea-level lowering events during the earlier half of the Miocene.

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