• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 6
  • 2
  • 2
  • Tagged with
  • 12
  • 12
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 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.
1

Behavior, association patterns and habitat use of a small community of bottlenose dolphins in San Luis Pass, Texas

Henderson, Erin Elizabeth 01 November 2005 (has links)
Photoidentification surveys of bottlenose dolphins (Tursiops truncatus) were conducted from December of 2002 through December of 2003 in Chocolate Bay, Texas, and the adjacent Gulf of Mexico area. The research represented the continuation of an ongoing study of the dolphins of this area. Behavioral sampling was carried out on a small resident community of dolphins that seasonally reside in Chocolate Bay, as well as on dolphins found along the gulf coastline. Resident dolphins had a daily behavioral pattern, with peaks of foraging activity in the morning, traveling at midday, and socializing in late afternoon. Gulf dolphins had small mean group sizes of 3.4 and were primarily observed foraging and traveling, with little socializing. When resident and gulf dolphins interacted, the mean group size increased to 12 and the proportion of social behavior increased. Association indices demonstrated no long-lasting associations among adult male dolphins, while strong associations existed between several females. Females revealed two patterns of association; they were either members of a female band with other mother-calf pairs, or were solitary with no strong affiliations with any dolphins other than their calf. Males seemed to disperse upon maturation, which maintained the community size of approximately 35 animals. Behavioral evidence indicates the resident community is matrilinealy related and composed largely of adult females and their offspring. A few adult males remain resident, while most young males disperse from the community and may rove among the gulf population. Although mating probably occurs between resident and gulf dolphins, sources of both maternity and paternity for residents need to be determined, and further behavioral work needs to be carried out to support this hypothesis.
2

Behavior, association patterns and habitat use of a small community of bottlenose dolphins in San Luis Pass, Texas

Henderson, Erin Elizabeth 01 November 2005 (has links)
Photoidentification surveys of bottlenose dolphins (Tursiops truncatus) were conducted from December of 2002 through December of 2003 in Chocolate Bay, Texas, and the adjacent Gulf of Mexico area. The research represented the continuation of an ongoing study of the dolphins of this area. Behavioral sampling was carried out on a small resident community of dolphins that seasonally reside in Chocolate Bay, as well as on dolphins found along the gulf coastline. Resident dolphins had a daily behavioral pattern, with peaks of foraging activity in the morning, traveling at midday, and socializing in late afternoon. Gulf dolphins had small mean group sizes of 3.4 and were primarily observed foraging and traveling, with little socializing. When resident and gulf dolphins interacted, the mean group size increased to 12 and the proportion of social behavior increased. Association indices demonstrated no long-lasting associations among adult male dolphins, while strong associations existed between several females. Females revealed two patterns of association; they were either members of a female band with other mother-calf pairs, or were solitary with no strong affiliations with any dolphins other than their calf. Males seemed to disperse upon maturation, which maintained the community size of approximately 35 animals. Behavioral evidence indicates the resident community is matrilinealy related and composed largely of adult females and their offspring. A few adult males remain resident, while most young males disperse from the community and may rove among the gulf population. Although mating probably occurs between resident and gulf dolphins, sources of both maternity and paternity for residents need to be determined, and further behavioral work needs to be carried out to support this hypothesis.
3

Expressions of Future in Present-day English: A Corpus-based Approach

Berglund, Ylva January 2005 (has links)
This corpus-based study of the use of expressions of future in English has two aims: to examine how certain expressions of future are used in Present-day English, and to explore how electronic corpora can be exploited for linguistic study. The expressions focused on in this thesis are five auxiliary or semi-auxiliary verb phrases frequently discussed in studies of future reference in English: will, ’ll, shall, going to and gonna. The study examines the patterned ways in which the expressions are used in association with various linguistic and non-linguistic (or extra-linguistic) factors. The linguistic factors investigated are co-occurrence with particular words and co-occurrence with items of particular grammatical classes. The non-linguistic factors examined are medium (written vs. spoken), text category, speaker characteristics (age, sex, social class, etc.), region and time. The data for the study are exclusively drawn from computer-readable corpora of Present-day English. Corpus analyses are performed with automatic and interactive methods, and exploit both quantitative and qualitative analytical techniques. The study finds that the use of these expressions of future varies with a number of factors. Differences between spoken and written language are particularly prominent and usage also varies between different types of text, both within spoken and written corpora. Variation between groups of speakers is also attested. Although the linguistic co-occurrence patterns are similar to some degree, there are nonetheless differences in the collocational patterns in which the expressions are used. Methodological issues related to corpus-based studies in general are discussed in the light of the insights gained from this study of expressions of future.
4

Expressions of Future in Present-day English: A Corpus-based Approach

Berglund, Ylva January 2005 (has links)
<p>This corpus-based study of the use of expressions of future in English has two aims: to examine how certain expressions of future are used in Present-day English, and to explore how electronic corpora can be exploited for linguistic study. </p><p>The expressions focused on in this thesis are five auxiliary or semi-auxiliary verb phrases frequently discussed in studies of future reference in English: <i>will</i>, <i>’ll</i>, <i>shall</i>, <i>going to</i> and <i>gonna</i>. The study examines the patterned ways in which the expressions are used in association with various linguistic and non-linguistic (or extra-linguistic) factors. The linguistic factors investigated are co-occurrence with particular words and co-occurrence with items of particular grammatical classes. The non-linguistic factors examined are medium (written vs. spoken), text category, speaker characteristics (age, sex, social class, etc.), region and time. The data for the study are exclusively drawn from computer-readable corpora of Present-day English. Corpus analyses are performed with automatic and interactive methods, and exploit both quantitative and qualitative analytical techniques.</p><p>The study finds that the use of these expressions of future varies with a number of factors. Differences between spoken and written language are particularly prominent and usage also varies between different types of text, both within spoken and written corpora. Variation between groups of speakers is also attested. Although the linguistic co-occurrence patterns are similar to some degree, there are nonetheless differences in the collocational patterns in which the expressions are used. </p><p>Methodological issues related to corpus-based studies in general are discussed in the light of the insights gained from this study of expressions of future.</p>
5

O genótipo do hospedeiro e as condições ambientais como moduladores da comunidade bacteriana associada / The host genotype and environmental conditions as modulators of the associated bacterial community

Andrade, Pedro Avelino Maia de 24 July 2017 (has links)
Sabe-se que humanos, plantas e animais são colonizados por uma elevada diversidade de microrganismos e que esses organismos eucariotos dependem destes microrganismos para manutenção do seu desenvolvimento. Usando dois modelos de associação microrganismo-hospedeiro, foi testado a hipótese de que hospedeiros pertencentes a domínios da vida distintos, apesar de suas particularidades estruturais, genotípicas, filogenéticas e fisiológicas, compartilham similaridades nos modos de associação com a comunidade bacteriana. Sendo assim, o objetivo do presente trabalho foi mapear a comunidade bacteriana associada a plantas do gênero Anthurium endêmicas e/ou não. Paralelamente, mapear a comunidade bacteriana associada a gêneros distintos de cianobactérias, ao longo da curva de crescimento e quando esta é submetida a condições de cultivo distintas. Como resultados, primeiramente, foi observado que plantas Anthurium alcatrazense endêmicas da Ilha apresentam riqueza e diversidade menor que as plantas da espécie Anthurium loefgrenii coletada na ilha de Alcatrazes e também menor que as plantas Anthurium intermedium e Anthurium pentaphyllum coletadas na região de continente. Também foi observado que a estrutura da comunidade bacteriana associada as plantas de A. alcatrazense é distinta quando comparada com as plantas coletadas no continente e também da própria ilha de Alcatrazes. Essa dissimilaridade foi principalmente representada por OTUs afiliadas à Betaproteobacteria e Gammaproteobacteria. Esses resultados sugerem especificidade microrganismo-hospedeiro. Considerando a associação cianobactéria e bactérias heterotróficas, os resultados demonstraram que a comunidade bacteriana associada é especifica de acordo com o gênero de cianobactéria, composta principalmente por classes apresentando abundância relativa de sequencias distintas como, Betaproteobacteria, Gammaproteobacteria, Flavobacteria e Cytophagia. Por outro lado, foi possível observar que ao longo das fases de multiplicação da linhagem Microcystis aeruginosa, ocorre uma sucessão de grupos bacterianos, sendo principalmente representado pela variação da abundância de Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria e Flavobacteria relativo a fase estacionaria de multiplicação. Quando submetida em condições de cultivo distintas, foi possível observar que variações nas taxas de multiplicação da cianobactéria influenciaram uma modulação da estrutura da comunidade bacteriana associada, desta forma sugerindo que rápidas alterações na estrutura da comunidade bacteriana associada a M. aeruginosa, é resultado de processos de auto-regulação entre cianobactéria e bactérias heterotróficas associadas. De forma geral, pode-se sugerir que hospedeiros distintos apresentam padrões de associações com as bactérias similares, podendo estas similaridades sugerir estratégias para um melhor entendimento e manejo dos ecossistemas. / It is known that humans, plants and animals are colonized by a high diversity of microorganisms and that these eukaryotic organisms depend on these microorganisms to maintain their development. Using two microorganism-host association models, we hypothesized that hosts belonging to distinct domains of life, despite their structural, genotypic, phylogenetic and physiological particularities, share similarities in the modes of association with the bacterial community. Thus, the objective of this work was to map the bacterial community associated with plants of the genus Anthurium endemic and / or not. In parallel, map the bacterial community associated with distinct genera of cyanobacteria, along the growth curve of and when it is submitted to different culture conditions. In this context, we observed that Anthurium alcatrazense plants endemic to the Island, present less richness and diversity than the plants of the species Anthurium loefgrenii collected in the island of Alcatrazes and smaller than the plants Anthurium intermedium and Anthurium penthaphyllum collected in the continent. We found that the structure of the bacterial community associated with the plants of A. alcatrazense is distinct when compared to the plants collected in the continent and island of Alcatrazes itself. This dissimilarity was mainly represented by OTUs affiliated with Betaproteobacteria and Gammaproteobacteria. These results suggest microorganism-host specificity. Considering the association cyanobacteria and heterotrophic bacteria, the results demonstrated that the associated bacterial community is specific according to the genus of cyanobacteria, composed mainly by abundance distinct from those of classes, Betaproteobacteria, Gammaproteobacteria, Flavobacteria and Cytophagia. On the other hand, it was possible to observe that during the multiplication stages of the Microcystis aeruginosa strain, a succession of bacterial groups occurs, mainly represented by the variation of the abundance of Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria and Flavobacteria relative to the stationary phase of multiplication. When submitted under different culture conditions, it was possible to observe that variations in cyanobacteria multiplication rates influenced a modulation of the associated bacterial community structure, thus suggesting that rapid changes in the bacterial community structure associated with M. aeruginosa is a result of processes of self-regulation between cyanobacteria and associated heterotrophic bacteria. In general, distinct hosts show patterns of associations with similar bacteria, and these similarities may suggest strategies for a better understanding and management of ecosystems.
6

Um estudo de longa duração de um grupo costeiro de golfinhos Tursiops truncatus (Montagu, 1821) (Cetacea, Delphinidae) no sul do Brasil : aspectos de sua biologia e bioacústica

Hoffmann, Lilian Sander January 2004 (has links)
Um pequeno grupo de golfinhos Tursiops truncatus, presente na barra da laguna de Tramandaí, RS, vem sendo acompanhado desde 1996 quanto a seus padrões de ocorrência e associação. A partir de 2002, tal acompanhamento passou a incluir dados de bioacústica. Através da fotoidentificação, os indivíduos foram observados na área em todos os anos, o que permite caracterizá-los como residentes, embora predominem os momentos em que estão ausentes. O tamanho do grupo é mantido constante, com oito indivíduos adultos, mas o nascimento de filhotes pode aumentar temporariamente este número, com até 11 golfinhos tendo sido observados num mesmo ano. Os nascimentos registrados para as duas fêmeas do grupo ocorreram em pelo menos duas épocas do ano (outono e primavera), num intervalo de aproximadamente 2,7 anos. Apesar da menor freqüência de observação durante o período de inverno, em todas as épocas dos anos de estudo foram observados animais na área, embora tenham variado em número e grau de associação, assim como também em diferentes graus de fidelidade, onde alguns animais foram vistos mais freqüentemente que outros. Animais solitários predominaram nas observações em qualquer período. Maiores agrupamentos foram mais freqüentes no outono, e secundariamente na primavera, coincidindo com a presença dos filhotes. Nas associações predominaram as duplas, embora grupos de até sete golfinhos tenham sido registrados. Ao contrário do esperado para grupos pequenos, os índices de associação de superfície foram baixos ao longo do período analisado. Índices fortes (>0,40) ocorreram somente entre fêmeas e filhotes, mas também temporariamente (em um dia) entre outros indivíduos, caracterizando sua organização social num continuum entre diferentes extremos de associação, provavelmente adaptada às condições ambientais e sociais. Na análise do repertório sonoro do grupo, foram registrados vários tipos de sons, desde assobios até cliques de ecolocalização e sons pulsantes, estes últimos bastante vinculados à atividade de alimentação. Foram analisados 1.768 assobios, dos quais identificou-se pelo menos cinco padrões gerais de modulação da freqüência fundamental: ascendente, descendente, côncavo, múltiplo e em forma de parábola (não sendo registrados assobios com modulação constante). Estes, por sua vez, permitiram o reconhecimento de pelo menos 34 subcategorias de assobios. Os assobios ascendentes predominaram nos registros, mas os outros dois padrões mais freqüentes (parábola e múltiplo) também foram representativos. O número e tipo de assobio variaram de acordo com o contexto, onde mais de 80% dos assobios foram registrados em momentos de associação. Assobios múltiplos foram mais freqüentemente registrados em associações, principalmente na presença de fêmeas e filhotes. Durante estas interações com filhotes, houve também a predominância de assobios ascendentes, mas as emissões apresentaram um padrão bastante distinto, com longas seqüências sendo registradas e a ocorrência de vários tipos de assobios diferentes, muitas vezes sobrepostos, sugerindo combinações que podem estar relacionadas a um aumento na troca de informações entre os animais, por sua vez vinculadas à importância da comunicação entre mães e filhotes neste período. Animais solitários emitiram predominantemente um tipo específico de assobio, com contorno da freqüência fundamental semelhante a uma parábola. Esta classe apresentou os tipos mais variados, e devido a estas variações na modulação da fundamental e sua freqüência de ocorrência em animais solitários, sugere-se que nesta categoria poderiam ser encontrados os assobios assinatura dos indivíduos deste grupo. O grande número de tipos de assobios encontrados, assim como a diferença nos contextos de emissão, sugere que os animais possuem um repertório variado, onde vários sinais parecem ser ainda compartilhados entre eles. Por fim, a comparação entre métodos de extração manuais e automáticos dos parâmetros acústicos não revelou diferenças significativas, viabilizando os resultados de ambas as técnicas. / The occurrence and association patterns of a small group of dolphins, Tursiops truncatus, inhabiting the Tramandaí lagoon, RS, have been studied since 1996. The study includes bioacoustics data since 2002. The individuals were observed in that area every year through photo-identification, which characterizes them as resident, although their absence is very frequent. The size of the group is quite constant, with eight adults, but the birth of calves increases this number temporarily, being 11 the largest group size observed in one year. The births recorded for the two females of this group occurred at least twice a year (autumn and spring), with an interval of approximately 2.7 years. Although less observed in the winter, animals were present in the area, with varying degrees of association and fidelity, some animals being observed more frequently than others. Solitary animals were frequent in any period. Larger groups were most frequent in autumn and secondarily in spring, due to the presence of calves. Regarding associations, pairs of dolphins were the most frequent form, although groups of up to seven dolphins were recorded. Different from the expected for small groups, surface association indexes were low in the whole period of the study. Strong association (>0.40) occurred only between females and calves; strong associations were temporary (one day) among other individuals, characterizing their social organization as a continuum from different extremes of association, probably adapted to social and environmental conditions. In the analysis of the sound repertory of the group, various kinds of vocalizations were observed, from whistles to clicks of echolocation and burst sounds, the latter ones associated to feeding activities. A total of 1768 whistles were observed, from which five general patterns of the fundamental frequency modulation were distinguished: Ascending, descending, concave, multiple and in parabolic form. Constant modulation whistles were not recorded. The five patterns allowed distinguishing at least 34 subcategories of whistles. Ascending whistles predominate in the records, but the other two frequent patterns (parabola and multiple) were also representative. The number and kind of whistles varied according to the context, where more than 80% of them were recorded in association periods. Multiple whistles were most frequently recorded in associations, mainly between females and calves. During this interaction, ascending whistles predominated, but vocalizations presented a very distinct pattern, with long sequences and several different kinds of whistles, sometimes superimposed, suggesting combinations which might be related to the importance of the communication between female and calf in this period. Solitary animals produced a specific kind of whistle, with a parabolic form around the fundamental frequency. This class presented the most varied kinds. Due to the frequency of occurrence as well as their variations in the modulation of the fundamental frequency, it is suggested that in this category one could find the individual signatures of this group. The large number of whistle kinds and the different contexts in which they were recorded suggest that the animals have a varied repertory, where several signals are shared among them. Finally, the comparison of manual and automatic extraction methods of acoustic parameters did not show meaningful differences, thus allowing the results of both techniques.
7

Um estudo de longa duração de um grupo costeiro de golfinhos Tursiops truncatus (Montagu, 1821) (Cetacea, Delphinidae) no sul do Brasil : aspectos de sua biologia e bioacústica

Hoffmann, Lilian Sander January 2004 (has links)
Um pequeno grupo de golfinhos Tursiops truncatus, presente na barra da laguna de Tramandaí, RS, vem sendo acompanhado desde 1996 quanto a seus padrões de ocorrência e associação. A partir de 2002, tal acompanhamento passou a incluir dados de bioacústica. Através da fotoidentificação, os indivíduos foram observados na área em todos os anos, o que permite caracterizá-los como residentes, embora predominem os momentos em que estão ausentes. O tamanho do grupo é mantido constante, com oito indivíduos adultos, mas o nascimento de filhotes pode aumentar temporariamente este número, com até 11 golfinhos tendo sido observados num mesmo ano. Os nascimentos registrados para as duas fêmeas do grupo ocorreram em pelo menos duas épocas do ano (outono e primavera), num intervalo de aproximadamente 2,7 anos. Apesar da menor freqüência de observação durante o período de inverno, em todas as épocas dos anos de estudo foram observados animais na área, embora tenham variado em número e grau de associação, assim como também em diferentes graus de fidelidade, onde alguns animais foram vistos mais freqüentemente que outros. Animais solitários predominaram nas observações em qualquer período. Maiores agrupamentos foram mais freqüentes no outono, e secundariamente na primavera, coincidindo com a presença dos filhotes. Nas associações predominaram as duplas, embora grupos de até sete golfinhos tenham sido registrados. Ao contrário do esperado para grupos pequenos, os índices de associação de superfície foram baixos ao longo do período analisado. Índices fortes (>0,40) ocorreram somente entre fêmeas e filhotes, mas também temporariamente (em um dia) entre outros indivíduos, caracterizando sua organização social num continuum entre diferentes extremos de associação, provavelmente adaptada às condições ambientais e sociais. Na análise do repertório sonoro do grupo, foram registrados vários tipos de sons, desde assobios até cliques de ecolocalização e sons pulsantes, estes últimos bastante vinculados à atividade de alimentação. Foram analisados 1.768 assobios, dos quais identificou-se pelo menos cinco padrões gerais de modulação da freqüência fundamental: ascendente, descendente, côncavo, múltiplo e em forma de parábola (não sendo registrados assobios com modulação constante). Estes, por sua vez, permitiram o reconhecimento de pelo menos 34 subcategorias de assobios. Os assobios ascendentes predominaram nos registros, mas os outros dois padrões mais freqüentes (parábola e múltiplo) também foram representativos. O número e tipo de assobio variaram de acordo com o contexto, onde mais de 80% dos assobios foram registrados em momentos de associação. Assobios múltiplos foram mais freqüentemente registrados em associações, principalmente na presença de fêmeas e filhotes. Durante estas interações com filhotes, houve também a predominância de assobios ascendentes, mas as emissões apresentaram um padrão bastante distinto, com longas seqüências sendo registradas e a ocorrência de vários tipos de assobios diferentes, muitas vezes sobrepostos, sugerindo combinações que podem estar relacionadas a um aumento na troca de informações entre os animais, por sua vez vinculadas à importância da comunicação entre mães e filhotes neste período. Animais solitários emitiram predominantemente um tipo específico de assobio, com contorno da freqüência fundamental semelhante a uma parábola. Esta classe apresentou os tipos mais variados, e devido a estas variações na modulação da fundamental e sua freqüência de ocorrência em animais solitários, sugere-se que nesta categoria poderiam ser encontrados os assobios assinatura dos indivíduos deste grupo. O grande número de tipos de assobios encontrados, assim como a diferença nos contextos de emissão, sugere que os animais possuem um repertório variado, onde vários sinais parecem ser ainda compartilhados entre eles. Por fim, a comparação entre métodos de extração manuais e automáticos dos parâmetros acústicos não revelou diferenças significativas, viabilizando os resultados de ambas as técnicas. / The occurrence and association patterns of a small group of dolphins, Tursiops truncatus, inhabiting the Tramandaí lagoon, RS, have been studied since 1996. The study includes bioacoustics data since 2002. The individuals were observed in that area every year through photo-identification, which characterizes them as resident, although their absence is very frequent. The size of the group is quite constant, with eight adults, but the birth of calves increases this number temporarily, being 11 the largest group size observed in one year. The births recorded for the two females of this group occurred at least twice a year (autumn and spring), with an interval of approximately 2.7 years. Although less observed in the winter, animals were present in the area, with varying degrees of association and fidelity, some animals being observed more frequently than others. Solitary animals were frequent in any period. Larger groups were most frequent in autumn and secondarily in spring, due to the presence of calves. Regarding associations, pairs of dolphins were the most frequent form, although groups of up to seven dolphins were recorded. Different from the expected for small groups, surface association indexes were low in the whole period of the study. Strong association (>0.40) occurred only between females and calves; strong associations were temporary (one day) among other individuals, characterizing their social organization as a continuum from different extremes of association, probably adapted to social and environmental conditions. In the analysis of the sound repertory of the group, various kinds of vocalizations were observed, from whistles to clicks of echolocation and burst sounds, the latter ones associated to feeding activities. A total of 1768 whistles were observed, from which five general patterns of the fundamental frequency modulation were distinguished: Ascending, descending, concave, multiple and in parabolic form. Constant modulation whistles were not recorded. The five patterns allowed distinguishing at least 34 subcategories of whistles. Ascending whistles predominate in the records, but the other two frequent patterns (parabola and multiple) were also representative. The number and kind of whistles varied according to the context, where more than 80% of them were recorded in association periods. Multiple whistles were most frequently recorded in associations, mainly between females and calves. During this interaction, ascending whistles predominated, but vocalizations presented a very distinct pattern, with long sequences and several different kinds of whistles, sometimes superimposed, suggesting combinations which might be related to the importance of the communication between female and calf in this period. Solitary animals produced a specific kind of whistle, with a parabolic form around the fundamental frequency. This class presented the most varied kinds. Due to the frequency of occurrence as well as their variations in the modulation of the fundamental frequency, it is suggested that in this category one could find the individual signatures of this group. The large number of whistle kinds and the different contexts in which they were recorded suggest that the animals have a varied repertory, where several signals are shared among them. Finally, the comparison of manual and automatic extraction methods of acoustic parameters did not show meaningful differences, thus allowing the results of both techniques.
8

Um estudo de longa duração de um grupo costeiro de golfinhos Tursiops truncatus (Montagu, 1821) (Cetacea, Delphinidae) no sul do Brasil : aspectos de sua biologia e bioacústica

Hoffmann, Lilian Sander January 2004 (has links)
Um pequeno grupo de golfinhos Tursiops truncatus, presente na barra da laguna de Tramandaí, RS, vem sendo acompanhado desde 1996 quanto a seus padrões de ocorrência e associação. A partir de 2002, tal acompanhamento passou a incluir dados de bioacústica. Através da fotoidentificação, os indivíduos foram observados na área em todos os anos, o que permite caracterizá-los como residentes, embora predominem os momentos em que estão ausentes. O tamanho do grupo é mantido constante, com oito indivíduos adultos, mas o nascimento de filhotes pode aumentar temporariamente este número, com até 11 golfinhos tendo sido observados num mesmo ano. Os nascimentos registrados para as duas fêmeas do grupo ocorreram em pelo menos duas épocas do ano (outono e primavera), num intervalo de aproximadamente 2,7 anos. Apesar da menor freqüência de observação durante o período de inverno, em todas as épocas dos anos de estudo foram observados animais na área, embora tenham variado em número e grau de associação, assim como também em diferentes graus de fidelidade, onde alguns animais foram vistos mais freqüentemente que outros. Animais solitários predominaram nas observações em qualquer período. Maiores agrupamentos foram mais freqüentes no outono, e secundariamente na primavera, coincidindo com a presença dos filhotes. Nas associações predominaram as duplas, embora grupos de até sete golfinhos tenham sido registrados. Ao contrário do esperado para grupos pequenos, os índices de associação de superfície foram baixos ao longo do período analisado. Índices fortes (>0,40) ocorreram somente entre fêmeas e filhotes, mas também temporariamente (em um dia) entre outros indivíduos, caracterizando sua organização social num continuum entre diferentes extremos de associação, provavelmente adaptada às condições ambientais e sociais. Na análise do repertório sonoro do grupo, foram registrados vários tipos de sons, desde assobios até cliques de ecolocalização e sons pulsantes, estes últimos bastante vinculados à atividade de alimentação. Foram analisados 1.768 assobios, dos quais identificou-se pelo menos cinco padrões gerais de modulação da freqüência fundamental: ascendente, descendente, côncavo, múltiplo e em forma de parábola (não sendo registrados assobios com modulação constante). Estes, por sua vez, permitiram o reconhecimento de pelo menos 34 subcategorias de assobios. Os assobios ascendentes predominaram nos registros, mas os outros dois padrões mais freqüentes (parábola e múltiplo) também foram representativos. O número e tipo de assobio variaram de acordo com o contexto, onde mais de 80% dos assobios foram registrados em momentos de associação. Assobios múltiplos foram mais freqüentemente registrados em associações, principalmente na presença de fêmeas e filhotes. Durante estas interações com filhotes, houve também a predominância de assobios ascendentes, mas as emissões apresentaram um padrão bastante distinto, com longas seqüências sendo registradas e a ocorrência de vários tipos de assobios diferentes, muitas vezes sobrepostos, sugerindo combinações que podem estar relacionadas a um aumento na troca de informações entre os animais, por sua vez vinculadas à importância da comunicação entre mães e filhotes neste período. Animais solitários emitiram predominantemente um tipo específico de assobio, com contorno da freqüência fundamental semelhante a uma parábola. Esta classe apresentou os tipos mais variados, e devido a estas variações na modulação da fundamental e sua freqüência de ocorrência em animais solitários, sugere-se que nesta categoria poderiam ser encontrados os assobios assinatura dos indivíduos deste grupo. O grande número de tipos de assobios encontrados, assim como a diferença nos contextos de emissão, sugere que os animais possuem um repertório variado, onde vários sinais parecem ser ainda compartilhados entre eles. Por fim, a comparação entre métodos de extração manuais e automáticos dos parâmetros acústicos não revelou diferenças significativas, viabilizando os resultados de ambas as técnicas. / The occurrence and association patterns of a small group of dolphins, Tursiops truncatus, inhabiting the Tramandaí lagoon, RS, have been studied since 1996. The study includes bioacoustics data since 2002. The individuals were observed in that area every year through photo-identification, which characterizes them as resident, although their absence is very frequent. The size of the group is quite constant, with eight adults, but the birth of calves increases this number temporarily, being 11 the largest group size observed in one year. The births recorded for the two females of this group occurred at least twice a year (autumn and spring), with an interval of approximately 2.7 years. Although less observed in the winter, animals were present in the area, with varying degrees of association and fidelity, some animals being observed more frequently than others. Solitary animals were frequent in any period. Larger groups were most frequent in autumn and secondarily in spring, due to the presence of calves. Regarding associations, pairs of dolphins were the most frequent form, although groups of up to seven dolphins were recorded. Different from the expected for small groups, surface association indexes were low in the whole period of the study. Strong association (>0.40) occurred only between females and calves; strong associations were temporary (one day) among other individuals, characterizing their social organization as a continuum from different extremes of association, probably adapted to social and environmental conditions. In the analysis of the sound repertory of the group, various kinds of vocalizations were observed, from whistles to clicks of echolocation and burst sounds, the latter ones associated to feeding activities. A total of 1768 whistles were observed, from which five general patterns of the fundamental frequency modulation were distinguished: Ascending, descending, concave, multiple and in parabolic form. Constant modulation whistles were not recorded. The five patterns allowed distinguishing at least 34 subcategories of whistles. Ascending whistles predominate in the records, but the other two frequent patterns (parabola and multiple) were also representative. The number and kind of whistles varied according to the context, where more than 80% of them were recorded in association periods. Multiple whistles were most frequently recorded in associations, mainly between females and calves. During this interaction, ascending whistles predominated, but vocalizations presented a very distinct pattern, with long sequences and several different kinds of whistles, sometimes superimposed, suggesting combinations which might be related to the importance of the communication between female and calf in this period. Solitary animals produced a specific kind of whistle, with a parabolic form around the fundamental frequency. This class presented the most varied kinds. Due to the frequency of occurrence as well as their variations in the modulation of the fundamental frequency, it is suggested that in this category one could find the individual signatures of this group. The large number of whistle kinds and the different contexts in which they were recorded suggest that the animals have a varied repertory, where several signals are shared among them. Finally, the comparison of manual and automatic extraction methods of acoustic parameters did not show meaningful differences, thus allowing the results of both techniques.
9

O genótipo do hospedeiro e as condições ambientais como moduladores da comunidade bacteriana associada / The host genotype and environmental conditions as modulators of the associated bacterial community

Pedro Avelino Maia de Andrade 24 July 2017 (has links)
Sabe-se que humanos, plantas e animais são colonizados por uma elevada diversidade de microrganismos e que esses organismos eucariotos dependem destes microrganismos para manutenção do seu desenvolvimento. Usando dois modelos de associação microrganismo-hospedeiro, foi testado a hipótese de que hospedeiros pertencentes a domínios da vida distintos, apesar de suas particularidades estruturais, genotípicas, filogenéticas e fisiológicas, compartilham similaridades nos modos de associação com a comunidade bacteriana. Sendo assim, o objetivo do presente trabalho foi mapear a comunidade bacteriana associada a plantas do gênero Anthurium endêmicas e/ou não. Paralelamente, mapear a comunidade bacteriana associada a gêneros distintos de cianobactérias, ao longo da curva de crescimento e quando esta é submetida a condições de cultivo distintas. Como resultados, primeiramente, foi observado que plantas Anthurium alcatrazense endêmicas da Ilha apresentam riqueza e diversidade menor que as plantas da espécie Anthurium loefgrenii coletada na ilha de Alcatrazes e também menor que as plantas Anthurium intermedium e Anthurium pentaphyllum coletadas na região de continente. Também foi observado que a estrutura da comunidade bacteriana associada as plantas de A. alcatrazense é distinta quando comparada com as plantas coletadas no continente e também da própria ilha de Alcatrazes. Essa dissimilaridade foi principalmente representada por OTUs afiliadas à Betaproteobacteria e Gammaproteobacteria. Esses resultados sugerem especificidade microrganismo-hospedeiro. Considerando a associação cianobactéria e bactérias heterotróficas, os resultados demonstraram que a comunidade bacteriana associada é especifica de acordo com o gênero de cianobactéria, composta principalmente por classes apresentando abundância relativa de sequencias distintas como, Betaproteobacteria, Gammaproteobacteria, Flavobacteria e Cytophagia. Por outro lado, foi possível observar que ao longo das fases de multiplicação da linhagem Microcystis aeruginosa, ocorre uma sucessão de grupos bacterianos, sendo principalmente representado pela variação da abundância de Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria e Flavobacteria relativo a fase estacionaria de multiplicação. Quando submetida em condições de cultivo distintas, foi possível observar que variações nas taxas de multiplicação da cianobactéria influenciaram uma modulação da estrutura da comunidade bacteriana associada, desta forma sugerindo que rápidas alterações na estrutura da comunidade bacteriana associada a M. aeruginosa, é resultado de processos de auto-regulação entre cianobactéria e bactérias heterotróficas associadas. De forma geral, pode-se sugerir que hospedeiros distintos apresentam padrões de associações com as bactérias similares, podendo estas similaridades sugerir estratégias para um melhor entendimento e manejo dos ecossistemas. / It is known that humans, plants and animals are colonized by a high diversity of microorganisms and that these eukaryotic organisms depend on these microorganisms to maintain their development. Using two microorganism-host association models, we hypothesized that hosts belonging to distinct domains of life, despite their structural, genotypic, phylogenetic and physiological particularities, share similarities in the modes of association with the bacterial community. Thus, the objective of this work was to map the bacterial community associated with plants of the genus Anthurium endemic and / or not. In parallel, map the bacterial community associated with distinct genera of cyanobacteria, along the growth curve of and when it is submitted to different culture conditions. In this context, we observed that Anthurium alcatrazense plants endemic to the Island, present less richness and diversity than the plants of the species Anthurium loefgrenii collected in the island of Alcatrazes and smaller than the plants Anthurium intermedium and Anthurium penthaphyllum collected in the continent. We found that the structure of the bacterial community associated with the plants of A. alcatrazense is distinct when compared to the plants collected in the continent and island of Alcatrazes itself. This dissimilarity was mainly represented by OTUs affiliated with Betaproteobacteria and Gammaproteobacteria. These results suggest microorganism-host specificity. Considering the association cyanobacteria and heterotrophic bacteria, the results demonstrated that the associated bacterial community is specific according to the genus of cyanobacteria, composed mainly by abundance distinct from those of classes, Betaproteobacteria, Gammaproteobacteria, Flavobacteria and Cytophagia. On the other hand, it was possible to observe that during the multiplication stages of the Microcystis aeruginosa strain, a succession of bacterial groups occurs, mainly represented by the variation of the abundance of Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria and Flavobacteria relative to the stationary phase of multiplication. When submitted under different culture conditions, it was possible to observe that variations in cyanobacteria multiplication rates influenced a modulation of the associated bacterial community structure, thus suggesting that rapid changes in the bacterial community structure associated with M. aeruginosa is a result of processes of self-regulation between cyanobacteria and associated heterotrophic bacteria. In general, distinct hosts show patterns of associations with similar bacteria, and these similarities may suggest strategies for a better understanding and management of ecosystems.
10

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 0.5476 seconds