• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 38
  • 21
  • 2
  • 2
  • 1
  • Tagged with
  • 80
  • 20
  • 12
  • 9
  • 9
  • 8
  • 8
  • 8
  • 7
  • 7
  • 7
  • 6
  • 6
  • 5
  • 5
  • 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.
61

Avaliação histopatológica de mamíferos marinhos encalhados no litoral do nordeste brasileiro / Marine mammals of assessment histopathological stranded in the brazilian northeast coast

Brito, Ana Paula Domingos 27 February 2015 (has links)
Made available in DSpace on 2016-08-31T13:29:07Z (GMT). No. of bitstreams: 1 AnaPDB_DISSERT.pdf: 5575228 bytes, checksum: a1c79702c349b805acdba52d04a353ce (MD5) Previous issue date: 2015-02-27 / Pathological examination of marine mammals carcasses is an important tool to understand the natural morphophysiology as well as the morphological changes associated with some diseases and thus highlight the potential anthropogenic impacts. This work had as aim conduct studies on histopathology of the organs of the dead stranded cetaceans and Sirenia in the Brazilian northeast coast, or that died during the rehabilitation process in Specialized Centers of the Region. For this, samples were taken belonging to the biological collection of Projeto Cetáceos da Costa Branca (PCCB), Associação de Pesquisa e Preservação de Ecossistemas Aquáticos (AQUASIS) and from Centro de Mamíferos Aquáticos (CMA). The tissue samples were submitted to the conventional method of preparing histological slides. Whereas the studied animals belong to different species, age and sex, a general descriptive analysis of the pathological aspects found in each case was carried out. From a total of 237 samples belonging to 66 individuals of the Cetacea order (n = 28) and Sirenia (n = 38), 34,17% (n = 81) exhibited microscopic changes, 54,85% (n = 130) were normal and 10,97% (n = 26) were autolysed. Among the obvious microscopic changes was diagnosed 50% of stomatitis in the oral system (n = 1), the heart showed 6.66% of interstitial fibrosis (n = 2), 10% of haemorrhage (n = 3) and 6.66% myocarditis (n = 2). The lungs showed pulmonary edema in 19% of the analyzes (n = 11), 10% of vascular congestion% (n = 6), 13% of haemorrhage (n = 8), 3% of emphysema (n = 2), 7% full of hemosiderin (n = 4), 3% of interstitial pneumonia (n = 2), 2% of eosinophilic pneumonia (n = 1), 2% of parasitic granuloma (n = 1), 2% of parasitic cyst (n = 1), 2% of traqueíte (n = 1). In the stomach was visualized a hemorrhage (16.66%; n = 1) and in the gut was detected nodular lymphoid hyperplasia (7%; n = 2), enteritis (4%; n = 1), blood vessels congestion (4%; n = 1) and vacuolar degeneration (4%; n = 1). The livers analysis showed 23% of vacuolar degeneration (n = 5), 9% of hepatocellular necrosis (n = 2), 9% moderate deposit of melanin granules (n = 2), 4.54 % of chronic hepatitis (n = 1), 9% of periportal fibrosis (n = 2), 4.54% of abscess (n = 1), 4.54% of congestion (n = 1), 4.54 % of bilestase (n = 1), and 4.54% proliferation of the bile ducts (n = 1). It was possible to observe in the spleen 20% white pulp rarefaction (n = 2), 10% white and red pulp rarefaction (n = 1), and 30% moderate deposition of melanin granules (n = 3). In the pancreas was observed a 50% of centroacinosas cells rarefaction (n = 1). In the kidneys was found 14% of toxix tube nephrosis (n = 4), 7% of multifocal hemorrhaging (n = 2), 14% of vascular congestion (n = 4), 3.44% presence of bacteria (n = 1), 3.44% of proliferative glomerulonephritis (n = 1), 3.44% of micro abscesses (n = 1), 3.44% of severe edema (n = 1), 3.44% of renal cysts (n = 1) and 3.44% of chronic interstitial nephritis (n = 1). In the uteri evaluated were observed 25% of a focal dystrophic calcification (n = 1) and 25% of metritis (n = 1). In the lymph nodes were observed suggestive abnormalities of immunosuppression (25%; n = 1), bleeding (25%; n = 1) and melanose (50%; n = 2). Other findings include rarefaction of the adrenal cells (50%, n = 1), fewer sperm cells into the lumen (14,28%; n = 2) or presence of only spermatogonia in the seminiferous tubules (21,42%; n = 3), and 25% focal hyperplasia of the bladder (n = 1). Despite the changes present in many systems, lung diseases were higher in cetaceans bodies and sirenians stranded on the Brazilian northeast coast / O estudo anatomopatológico das carcaças dos mamíferos marinhos é uma ferramenta importante para conhecer a morfofisiologia natural, bem como as alterações morfológicas associadas com algumas doenças e, desta forma, evidenciar os possíveis impactos antropogênicos. O presente trabalho teve como intuito realizar estudos sobre histopatologia dos órgãos de cetáceos e sirênios. Para isso, foram utilizadas amostras pertencentes ao acervo biológico do Projeto Cetáceos da Costa Branca (PCCB), da Associação de Pesquisa e Preservação de Ecossistemas Aquáticos (AQUASIS) e do Centro de Mamíferos Aquáticos (CMA). Os fragmentos teciduais foram submetidos ao método convencional de preparação de lâminas histológicas. As peças passaram pelos processos de desidratação e diafanização, banho em parafina líquida, inclusão em bloco, e posterior corte em micrótomo rotativo. Os cortes, de quatro a cinco micra de espessura, foram colocados em lâminas lapidadas e submetidos ao método de coloração Hematoxilina-eosina (H.E.), sendo então montados utilizando-se lamínula e resina sintética. Considerando que os animais em estudo pertencem a diferentes espécies, faixas etárias e sexo, foi realizada uma análise descritiva geral dos aspectos patológicos encontrados em cada caso. De um total de 237 amostras pertencentes a 66 indivíduos da ordem Cetacea (n=28) e Sirenia (n=38), 34,17% (n=81) apresentaram alterações microscópicas, 54,85% (n=130) estavam normais e 10,97% (n=26) se encontravam autolisadas. Dentre as alterações microscópicas evidentes foi diagnosticado no sistema bucal 50% de estomatite (n=1), o coração apresentou 6,66% de fibrose intersticial (n=2), 10% de hemorragia (n=3) e 6,66% de miocardite (n=2). Os pulmões mostraram em 19% das análises edema pulmonar (n=11), 10% de congestão vascular (n=6), 13% de hemorragia (n=8), 3% de enfisema (n=2), 7% hemossiderose (n=4), 3% pneumonia intersticial (n=2), 2% de pneumonia eosinofílica (n=1), 2% de granuloma parasitário (n=1), 2% de cisto parasitário (n=1), 2% de traqueíte (n=1). No estômago foi visualizado em um sirênio áreas extensas de hemorragia (16,66%; n=1) e no intestino foi detectado hiperplasia nodular linfóide (7%; n=2), enterite (4%; n=1), congestão dos vasos (4%; n=1) e degeneração vacuolar (4%; n=1). Os fígados analisados mostraram 23% de degeneração vacuolar (n=5), 9% de necrose hepatocelular (n=2), 9% de depósito moderado de grânulos de melanina (n=2), 4,54% de hepatite crônica (n=1), 9% de fibrose periportal (n=2), 4,54% de abscesso (n=1), 4,54% de congestão (n=1), 4,54% de bilestase (n=1), e 4,54% de proliferação dos ductos biliares (n=1). Nos baços foi possível constatar 20% de rarefação de polpa branca (n=2), 10% de rarefação de polpa branca e vermelha (n=1), e 30% de deposição moderada de grânulos de melanina (n=3). No pâncreas foi observado uma rarefação das células centroacinosas em 50% (n=1) das amostras. Nos rins foi encontrado 14% de nefrose tubular tóxica (n=4), 7% de hemorragia multifocal (n=2), 14% de congestão vascular (n=4), 3,44% de presença de bactérias (n=1), 3,44% de glomerulonefrite proliferativa (n=1), 3,44% de microabscessos (n=1), 3,44% de edema severo (n=1), 3,44% de cistos renais (n=1) e 3,44% de nefrite intersticial crônica (n=1). Nos úteros avaliados foi observado 25% de calcificação distrófica focal (n=1) e 25% de metrite (n=1). Nos linfonodos foram observados alterações sugestivas de imunossupressão (25%; n=1), hemorragia (25%; n=1), e melanose (50%; n=2). Outros achados incluíram rarefação das células da adrenal (50%, n=1), poucos espermatozoides no lúmen (14,28%; n=2) ou presença apenas de espermatogônias nos túbulos seminíferos (21,42%; n=3), e 25% de hiperplasia focal da bexiga (n=1). Apesar das alterações presentes em diversos sistemas, as patologias pulmonares foram superiores as demais tanto em órgãos de cetáceos como em sirênios encalhados no litoral do nordeste brasileiro
62

EVOLUTION AND DEVELOPMENT OF CETACEAN APPENDAGES

Cooper, Lisa Noelle 02 November 2009 (has links)
No description available.
63

Influence of natural factors and anthropogenic stressors on sperm whale foraging effort and success at high latitudes

Isojunno, Saana January 2015 (has links)
Behavioural responses can reveal important fitness trade-offs and ecological traps in evolutionarily novel contexts created by anthropogenic stimuli, and are of increasing conservation concern due to possible links to population-level impacts. This thesis illustrates the use of proxies for energy acquisition and expenditure within multivariate and state-based modelling approaches to quantify the relative time and energetic costs of behavioural disturbance for a deep-diving marine mammal (Physeter macrocephalus) in foraging grounds in Kaikoura Canyon (New Zealand) and near Lofoten Islands (Norway). A conceptual framework is first developed to identify and explore links between individual motivation, condition and external constraints to behavioural disturbance [Chapter 1]. The following chapters then use data from behavioural response studies (BRS) to: 1) derive biologically relevant metrics of behaviour [all chapters], 2) investigate effects of boat-based focal follows and tagging procedures [Chapters 2-3], and 3) relate responses to specific disturbance stimuli (distance, approach, noise) from whale-watching [Chapter 2], naval sonar and playback of presumed natural predator (killer whale Orcinus orca) sounds [Chapter 4]. A novel hidden state model was developed to estimate behavioural budgets of tagged sperm whales from multiple streams of biologging (DTAG) data [Chapter 3]. Sperm whales traded off time spent at foraging depths in a non-foraging and non-resting state in response to both tag boat presence, 1-2 kHz naval sonar (SPL 131-165 rms re 1μPa) and mammal-eating killer whale sound playbacks, indicating that parallel non-lethal costs were incurred in both anthropogenic disturbance and presumed antipredatory contexts. While behavioural responses were highly variable by individual, biologically informed state-based models appeared effective to control for variability in energy proxies across different functional contexts. These results and Chapter 5 “linking buzzes to prey” demonstrate that behavioural context is a signal that can aid understanding of how individual non-lethal disturbance responses can impact fitness.
64

An investigation of factors related to the bycatch of small cetaceans in fishing gear

Mackay, Alice I. January 2011 (has links)
The bycatch of cetaceans in fishing gear is considered to be one of the biggest conservation threats to these species. Gear modifications have the potential to reduce these bycatches in global fisheries but there is little available information on how such modifications may change the fishing performance of gear, or indeed the behavior of cetaceans interacting with fishing gear. Generalized linear models (GLMs) were used to identify factors related to cetacean bycatches in UK bottom set gillnets. Rigged net height had a significant positive relationship with harbour porpoise (Phocoena phocoena) bycatch in ICES Area VII suggesting that lowering the profile of gillnets may have the potential to reduce bycatch rates. Modifications to gillnets, such as changing the amount of floatation or increasing the density of the meshes, were found to have significant effects on the active fishing heights of these nets. However, results from a bycatch mitigation trial in Argentina showed that the reduced fishing profile of one experimental net did not result in a concurrent reduction in the bycatch rate of Franciscana dolphins (Pontoporia blainvillei). While there was no significant difference in the rate, length or intensity of harbour porpoise encounters in the presence or absence of gillnets, the proportion of fast echolocation click trains were significantly higher when a net was present, indicating that porpoises either increased acoustic inspection of the net or foraging in the vicinity of the net. An analysis of underwater video footage collected inside trawl nets in an Australia fishery showed that bottlenose dolphins (Tursiops sp.) were present inside nets more frequently than they were caught and were actively foraging inside these nets. The orientation of dolphins inside these nets indicates that the current design of excluder devices used in this fishery could be improved to further reduce bycatch rates.
65

Análise morfológica da superfície de interface epitélio-tecido conjuntivo da face dorsal da língua de cetáceos (ordem Cetacea subordem Odontoceti), empregando os métodos de microscopia de luz e eletrônica de varredura / Morphologic analysis of the interface epithelium-connective tissue surface of the dorsal face of the cetaceans tongue (order cetacea sub-order odontoceti), using the light and scanning electron microscopic methods

Guimarães, Juliana Plácido 17 March 2006 (has links)
A ordem Cetacea compreende golfinhos e baleias, mamíferos totalmente adaptados ao ambiente aquático. A língua de duas espécies de cetáceos, Pontoporia blainvillei e Sotalia fluviatilis, foram utilizadas para descrição da morfologia das papilas linguais e da superfície de interface epitélio-tecido conjuntivo da lâmina própria, empregando as técnicas de microscopia de luz e eletrônica de varredura. As línguas foram fixadas e divididas em três porções: rostral, médio e caudal e processadas conforme os protocolos das técnicas utilizadas. A língua da Pontoporia blainvillei e Sotalia fluviatilis estava revestida por um epitélio estratificado queratinizado, sendo possível observar as camadas basal, espinhosa, granulosa e córnea. Pode-se notar que na língua, o tecido conjuntivo denso apresentava vasos sanguíneos e profundamente relacionado com o tecido muscular. A superfície de interface epitélio-tecido conjuntivo da lâmina própria apresentou papilas conjuntivas de várias formas. Elas correspondem às papilas filiformes e valadas, mostrando feixes de fibras colágenas em disposição original. Na microscopia de luz polarizada revelou-se fibras colágenas do tipo I e III. No terço médio e caudal de ambas as espécies foram encontradas ácinos de glândulas salivares. As amostras tratadas com solução de hidróxido de sódio, tiveram a camada epitelial removida, e as papilas conjuntivas foram observadas em aspecto tridimensional. Foi possível observar que a superfície dorsal de ambas as espécies é totalmente recoberta por papilas conjuntivas de aspecto filiforme. Observa-se também a presença dos forames dos ductos das glândulas salivares nas porções média e caudal da língua, sendo eles mais numerosos nos filhotes. Morfometricamente, as papilas conjuntivas apresentaram maior comprimento na espécie Sotalia fluviatilis do que na Pontoporia blainville. Foi observado somente na espécie Pontoporia blainvillei estruturas conjuntivas arredondadas na região média e caudal. Embora as áreas dessas estruturas tenham sido maiores na região caudal que na média, estatisticamente estes resultados não foram significativos (P>0,05). / The Cetacea order comprises dolphins and whales, mammals totally adapted to the aquatic ambient. The tongue of two cetaceans species, Pontoporia blainvillei and Sotalia fluviatilis, was studied for description of the morphology of the lingual papillae and of interface epithelium the connective tissue surface, using the light and scanning electron microscopic techniques. The tongues were fixed and divided in three portions: rostral, medium and caudal and treated according to the protocols of techniques used. The tongues of the Pontoporia blainvillei and Sotalia fluviatilis were covered by keratinized stratified epithelium, being that is possible to verify the basal, spinosa, granular and cornetiel ayers. In the tongue the dense connective tissue of lamina propria showed blood vessels and muscular layer was deeply related. The interface epithelium-connective tissue surface of the lamina propria presented connective tissue papillae which are various in shape. They correspond to the filiform and vallate papillae showing the collagen fibers bunches in original disposition. In the polarized light microscopy revealed collagen fibers type I and III. In the medium and caudal third of both species various groupins of salivary gland acini. The samples treated with sodium hydroxide solution, the epithelial layer was removed and the connective tissue papillae were observed in three-dimensional SEM images. It was possible to observe that the dorsal surface of the both species is totally covered by connective tissue papillae of filiform aspect. We observed also the presence of the ducts of the salivary glands in the media and caudal portions of the tongue, being them more numerous in pups. Morphometric analysis showed that the connective tissue papillae presented larger length in the Sotalia fluviatilis than in the Pontoporia blainville samples. The round connectives structures in the media and caudal portions were observed only the Pontoporia blainvillei species. Although, the areas of those structures have been major in the caudal region than media, and these results were not signifficant (P>0,05).
66

Acumulação de compostos organoclorados (PCBs, DDTs e HCB) em tecido hepático de delfinídeos (Cetacea, Mammalia) do Estado do Rio de Janeiro / Organochlorine compounds accumulation (PCBs, DDTs and HCB) in hepatic tissue of delphinids (Cetacea, Mammalia) from Rio de Janeiro State

Leticiaà Nadine Alves Legat 25 February 2011 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / No decorrer das últimas décadas a pesquisa relacionada à contaminação de organismos marinhos por compostos organoclorados (OCs) se intensificou aliada à utilização de algumas espécies como sentinelas da qualidade ambiental quanto aos poluentes orgânicos. Dentre essas espécies, podem-se destacar os cetáceos, animais que entre outras características possuem grande longevidade, alta porcentagem lipídica em seus tecidos e são predadores de topo de cadeia trófica, tendendo assim a acumular altos níveis de OCs em seus tecidos. O presente estudo teve por objetivo determinar as concentrações de OCs de origem industrial e agrícola (PCBs, HCB e DDTs) em tecido hepático de oito diferentes espécies de cetáceos delfinídeos pertencentes a três distintas áreas oceânicas do Estado do Rio de Janeiro, são elas a região costeira, a plataforma continental e a região oceânica. A determinação foi realizada em cromatógrafo a gás (GC - Agilent 6890) conectado a um espectrômetro de massa (MS - Agilent 5973). Os valores de DDTs (1263617272 ng.g -1 lip.) e PCBs (7648877288 ng.g -1 lip.) aqui encontrados estão entre os mais altos já reportados para o táxon. Em todas as áreas observou-se uma predominância do ΣPCB, seguida do ΣDDT e HCB, em níveis que refletem o caráter fortemente industrial da região analisada. Entre os PCBs, a maior contribuição advém dos hexabifenis, seguida dos hepta e pentabifenis, sendo os congêneres 153, 138 e 180 os principais em todas as áreas. A razão p,pDDE/ΣDp,pDDT foi alta em todas as regiões (0,9), refletindo um input antigo do poluente na área. Foram realizadas correlações entre as concentrações de OCs e os parâmetros biológicos das espécies, como idade, sexo e comprimento total. A transferência placentária de OCs foi analisada em dois pares de fêmea-feto de Sotalia guianensis, mostrando uma maior transferência dos compostos com menor log Kow. Como esperado, foi encontrada uma diferença significativa no perfil de contaminação entre as espécies das diferentes regiões, relacionada à proximidade da fonte, características espécie-específicas e ao arranjo trófico das espécies. / Over the past decades the research on marine organisms contamination by organochlorine compounds (OCs) has been intensified, allied to the utilization of some species as sentinels of the environmental quality related to organic pollutants. Among these species, cetaceans stand out as animals that, between other characteristics, have great longevity, high lipid percentage on their tissues and are top predators in food chains, therefore having the tendency to accumulate high OCs levels in their tissues. The present study aimed to determine OCs concentrations from industrial and agricultural sources (PCBs, HCB and DDTs) in hepatic tissue of eight different species of delphinid cetaceans belonging to three different oceanic areas of Rio de Janeiro State, namely, coastal region, continental shelf and oceanic region. The determination was performed in an Agilent 6890 gas chromatograph (GC) connected to an Agilent 5973 mass spectrometer (MS). DDTs (1263617272 ng.g -1 lip.) and PCBs (7648877288 ng.g -1 lip.) values reported here are amongst the highest values ever reported for the taxon. In all areas ΣPCB predominance was observed, followed by ΣDDT and HCB in levels that reflect the highly industrial character of the analyzed region. Amongst PCBs, the largest contribution comes from hexa biphenyls, followed by hepta and penta biphenyls, being the 153, 138 and 180 the main congeners in all areas. The p,pDDE/ΣDp,pDDT ratio was high in all regions (0,9), reflecting an ancient input of the pollutant in the area. Correlations between OCs concentrations and biologic parameters such as age, sex and total body lenght were performed. OCs placental transfer was analyzed in two Sotalia guianensis mother-fetus pairs, showing a higher transfer of compounds with lower log Kow. As expected, a significant difference was found on the contamination profile between species from the different regions, related to source proximity, species-specific characteristics and the species trophic arrangement.
67

Acumulação de compostos organoclorados (PCBs, DDTs e HCB) em tecido hepático de delfinídeos (Cetacea, Mammalia) do Estado do Rio de Janeiro / Organochlorine compounds accumulation (PCBs, DDTs and HCB) in hepatic tissue of delphinids (Cetacea, Mammalia) from Rio de Janeiro State

Leticiaà Nadine Alves Legat 25 February 2011 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / No decorrer das últimas décadas a pesquisa relacionada à contaminação de organismos marinhos por compostos organoclorados (OCs) se intensificou aliada à utilização de algumas espécies como sentinelas da qualidade ambiental quanto aos poluentes orgânicos. Dentre essas espécies, podem-se destacar os cetáceos, animais que entre outras características possuem grande longevidade, alta porcentagem lipídica em seus tecidos e são predadores de topo de cadeia trófica, tendendo assim a acumular altos níveis de OCs em seus tecidos. O presente estudo teve por objetivo determinar as concentrações de OCs de origem industrial e agrícola (PCBs, HCB e DDTs) em tecido hepático de oito diferentes espécies de cetáceos delfinídeos pertencentes a três distintas áreas oceânicas do Estado do Rio de Janeiro, são elas a região costeira, a plataforma continental e a região oceânica. A determinação foi realizada em cromatógrafo a gás (GC - Agilent 6890) conectado a um espectrômetro de massa (MS - Agilent 5973). Os valores de DDTs (1263617272 ng.g -1 lip.) e PCBs (7648877288 ng.g -1 lip.) aqui encontrados estão entre os mais altos já reportados para o táxon. Em todas as áreas observou-se uma predominância do ΣPCB, seguida do ΣDDT e HCB, em níveis que refletem o caráter fortemente industrial da região analisada. Entre os PCBs, a maior contribuição advém dos hexabifenis, seguida dos hepta e pentabifenis, sendo os congêneres 153, 138 e 180 os principais em todas as áreas. A razão p,pDDE/ΣDp,pDDT foi alta em todas as regiões (0,9), refletindo um input antigo do poluente na área. Foram realizadas correlações entre as concentrações de OCs e os parâmetros biológicos das espécies, como idade, sexo e comprimento total. A transferência placentária de OCs foi analisada em dois pares de fêmea-feto de Sotalia guianensis, mostrando uma maior transferência dos compostos com menor log Kow. Como esperado, foi encontrada uma diferença significativa no perfil de contaminação entre as espécies das diferentes regiões, relacionada à proximidade da fonte, características espécie-específicas e ao arranjo trófico das espécies. / Over the past decades the research on marine organisms contamination by organochlorine compounds (OCs) has been intensified, allied to the utilization of some species as sentinels of the environmental quality related to organic pollutants. Among these species, cetaceans stand out as animals that, between other characteristics, have great longevity, high lipid percentage on their tissues and are top predators in food chains, therefore having the tendency to accumulate high OCs levels in their tissues. The present study aimed to determine OCs concentrations from industrial and agricultural sources (PCBs, HCB and DDTs) in hepatic tissue of eight different species of delphinid cetaceans belonging to three different oceanic areas of Rio de Janeiro State, namely, coastal region, continental shelf and oceanic region. The determination was performed in an Agilent 6890 gas chromatograph (GC) connected to an Agilent 5973 mass spectrometer (MS). DDTs (1263617272 ng.g -1 lip.) and PCBs (7648877288 ng.g -1 lip.) values reported here are amongst the highest values ever reported for the taxon. In all areas ΣPCB predominance was observed, followed by ΣDDT and HCB in levels that reflect the highly industrial character of the analyzed region. Amongst PCBs, the largest contribution comes from hexa biphenyls, followed by hepta and penta biphenyls, being the 153, 138 and 180 the main congeners in all areas. The p,pDDE/ΣDp,pDDT ratio was high in all regions (0,9), reflecting an ancient input of the pollutant in the area. Correlations between OCs concentrations and biologic parameters such as age, sex and total body lenght were performed. OCs placental transfer was analyzed in two Sotalia guianensis mother-fetus pairs, showing a higher transfer of compounds with lower log Kow. As expected, a significant difference was found on the contamination profile between species from the different regions, related to source proximity, species-specific characteristics and the species trophic arrangement.
68

Análise morfológica da superfície de interface epitélio-tecido conjuntivo da face dorsal da língua de cetáceos (ordem Cetacea subordem Odontoceti), empregando os métodos de microscopia de luz e eletrônica de varredura / Morphologic analysis of the interface epithelium-connective tissue surface of the dorsal face of the cetaceans tongue (order cetacea sub-order odontoceti), using the light and scanning electron microscopic methods

Juliana Plácido Guimarães 17 March 2006 (has links)
A ordem Cetacea compreende golfinhos e baleias, mamíferos totalmente adaptados ao ambiente aquático. A língua de duas espécies de cetáceos, Pontoporia blainvillei e Sotalia fluviatilis, foram utilizadas para descrição da morfologia das papilas linguais e da superfície de interface epitélio-tecido conjuntivo da lâmina própria, empregando as técnicas de microscopia de luz e eletrônica de varredura. As línguas foram fixadas e divididas em três porções: rostral, médio e caudal e processadas conforme os protocolos das técnicas utilizadas. A língua da Pontoporia blainvillei e Sotalia fluviatilis estava revestida por um epitélio estratificado queratinizado, sendo possível observar as camadas basal, espinhosa, granulosa e córnea. Pode-se notar que na língua, o tecido conjuntivo denso apresentava vasos sanguíneos e profundamente relacionado com o tecido muscular. A superfície de interface epitélio-tecido conjuntivo da lâmina própria apresentou papilas conjuntivas de várias formas. Elas correspondem às papilas filiformes e valadas, mostrando feixes de fibras colágenas em disposição original. Na microscopia de luz polarizada revelou-se fibras colágenas do tipo I e III. No terço médio e caudal de ambas as espécies foram encontradas ácinos de glândulas salivares. As amostras tratadas com solução de hidróxido de sódio, tiveram a camada epitelial removida, e as papilas conjuntivas foram observadas em aspecto tridimensional. Foi possível observar que a superfície dorsal de ambas as espécies é totalmente recoberta por papilas conjuntivas de aspecto filiforme. Observa-se também a presença dos forames dos ductos das glândulas salivares nas porções média e caudal da língua, sendo eles mais numerosos nos filhotes. Morfometricamente, as papilas conjuntivas apresentaram maior comprimento na espécie Sotalia fluviatilis do que na Pontoporia blainville. Foi observado somente na espécie Pontoporia blainvillei estruturas conjuntivas arredondadas na região média e caudal. Embora as áreas dessas estruturas tenham sido maiores na região caudal que na média, estatisticamente estes resultados não foram significativos (P>0,05). / The Cetacea order comprises dolphins and whales, mammals totally adapted to the aquatic ambient. The tongue of two cetaceans species, Pontoporia blainvillei and Sotalia fluviatilis, was studied for description of the morphology of the lingual papillae and of interface epithelium the connective tissue surface, using the light and scanning electron microscopic techniques. The tongues were fixed and divided in three portions: rostral, medium and caudal and treated according to the protocols of techniques used. The tongues of the Pontoporia blainvillei and Sotalia fluviatilis were covered by keratinized stratified epithelium, being that is possible to verify the basal, spinosa, granular and cornetiel ayers. In the tongue the dense connective tissue of lamina propria showed blood vessels and muscular layer was deeply related. The interface epithelium-connective tissue surface of the lamina propria presented connective tissue papillae which are various in shape. They correspond to the filiform and vallate papillae showing the collagen fibers bunches in original disposition. In the polarized light microscopy revealed collagen fibers type I and III. In the medium and caudal third of both species various groupins of salivary gland acini. The samples treated with sodium hydroxide solution, the epithelial layer was removed and the connective tissue papillae were observed in three-dimensional SEM images. It was possible to observe that the dorsal surface of the both species is totally covered by connective tissue papillae of filiform aspect. We observed also the presence of the ducts of the salivary glands in the media and caudal portions of the tongue, being them more numerous in pups. Morphometric analysis showed that the connective tissue papillae presented larger length in the Sotalia fluviatilis than in the Pontoporia blainville samples. The round connectives structures in the media and caudal portions were observed only the Pontoporia blainvillei species. Although, the areas of those structures have been major in the caudal region than media, and these results were not signifficant (P>0,05).
69

Novel methods for species distribution mapping including spatial models in complex regions

Scott-Hayward, Lindesay Alexandra Sarah January 2013 (has links)
Species Distribution Modelling (SDM) plays a key role in a number of biological applications: assessment of temporal trends in distribution, environmental impact assessment and spatial conservation planning. From a statistical perspective, this thesis develops two methods for increasing the accuracy and reliability of maps of density surfaces and provides a solution to the problem of how to collate multiple density maps of the same region, obtained from differing sources. From a biological perspective, these statistical methods are used to analyse two marine mammal datasets to produce accurate maps for use in spatial conservation planning and temporal trend assessment. The first new method, Complex Region Spatial Smoother [CReSS; Scott-Hayward et al., 2013], improves smoothing in areas where the real distance an animal must travel (`as the animal swims') between two points may be greater than the straight line distance between them, a problem that occurs in complex domains with coastline or islands. CReSS uses estimates of the geodesic distance between points, model averaging and local radial smoothing. Simulation is used to compare its performance with other traditional and recently-developed smoothing techniques: Thin Plate Splines (TPS, Harder and Desmarais [1972]), Geodesic Low rank TPS (GLTPS; Wang and Ranalli [2007]) and the Soap lm smoother (SOAP; Wood et al. [2008]). GLTPS cannot be used in areas with islands and SOAP can be very hard to parametrise. CReSS outperforms all of the other methods on a range of simulations, based on their fit to the underlying function as measured by mean squared error, particularly for sparse data sets. Smoothing functions need to be flexible when they are used to model density surfaces that are highly heterogeneous, in order to avoid biases due to under- or over-fitting. This issue was addressed using an adaptation of a Spatially Adaptive Local Smoothing Algorithm (SALSA, Walker et al. [2010]) in combination with the CReSS method (CReSS-SALSA2D). Unlike traditional methods, such as Generalised Additive Modelling, the adaptive knot selection approach used in SALSA2D naturally accommodates local changes in the smoothness of the density surface that is being modelled. At the time of writing, there are no other methods available to deal with this issue in topographically complex regions. Simulation results show that CReSS-SALSA2D performs better than CReSS (based on MSE scores), except at very high noise levels where there is an issue with over-fitting. There is an increasing need for a facility to combine multiple density surface maps of individual species in order to make best use of meta-databases, to maintain existing maps, and to extend their geographical coverage. This thesis develops a framework and methods for combining species distribution maps as new information becomes available. The methods use Bayes Theorem to combine density surfaces, taking account of the levels of precision associated with the different sets of estimates, and kernel smoothing to alleviate artefacts that may be created where pairs of surfaces join. The methods were used as part of an algorithm (the Dynamic Cetacean Abundance Predictor) designed for BAE Systems to aid in risk mitigation for naval exercises. Two case studies show the capabilities of CReSS and CReSS-SALSA2D when applied to real ecological data. In the first case study, CReSS was used in a Generalised Estimating Equation framework to identify a candidate Marine Protected Area for the Southern Resident Killer Whale population to the south of San Juan Island, off the Pacific coast of the United States. In the second case study, changes in the spatial and temporal distribution of harbour porpoise and minke whale in north-western European waters over a period of 17 years (1994-2010) were modelled. CReSS and CReSS-SALSA2D performed well in a large, topographically complex study area. Based on simulation results, maps produced using these methods are more accurate than if a traditional GAM-based method is used. The resulting maps identified particularly high densities of both harbour porpoise and minke whale in an area off the west coast of Scotland in 2010, that might be a candidate for inclusion into the Scottish network of Nature Conservation Marine Protected Areas.
70

Genetic characterisation and social structure of the East Scotland population of bottlenose dolphins (Tursiops truncatus)

Islas, Valentina January 2010 (has links)
The Eastern Scottish population of bottlenose dolphins (Tursiops truncatus) is the northernmost population of this species. The resident core of this population consists of 120 to 150 different individuals. This small size and its geographical isolation from other populations raises questions about its viability and whether the population has behavioural patterns that differ from those common to other populations of the same species. Microsatellite genetic diversity was low and mitochondrial DNA genetic diversity values were lowest in East Scotland compared to other populations worldwide and to neighbouring populations around UK waters. It has been well documented, from four different field sites worldwide, that male bottlenose dolphins form alliances with preferred male associates. These alliances can last for several years and the males involved show association coefficients similar to those of mothers and calves (0.8-1.0). These alliances appear to be of great importance in obtaining matings for the males. In the Eastern Scottish population males do not form alliances. No evidence of strong associations between individuals of either sex was found and there was no correlation between association and relatedness patterns. I suggest that the isolation and small size of the population together with reduced genetic diversity affects the pressure of kin selection for altruistic behaviours. There is no gain in competing or associating with close relatives for access to mates and it might be more important to avoid inbreeding by dispersing. Although evidence of gene flow between East Scotland and its neighbouring populations was not confirmed with Bayesian clustering analysis, a small set of individuals from Wales were found to be closely related to individuals from the East Coast of Scotland. In general the dynamics found in UK water populations resemble those of the Western North Atlantic with sympatric populations of coastal as well as pelagic individuals.

Page generated in 0.053 seconds