Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2018-07-04T19:40:19Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) paula_cristina_barros_andrade.pdf: 4804696 bytes, checksum: 4747b9532db16586177823f2a1eb0977 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2018-07-18T13:01:12Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) paula_cristina_barros_andrade.pdf: 4804696 bytes, checksum: 4747b9532db16586177823f2a1eb0977 (MD5) / Made available in DSpace on 2018-07-18T13:01:12Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) paula_cristina_barros_andrade.pdf: 4804696 bytes, checksum: 4747b9532db16586177823f2a1eb0977 (MD5) Previous issue date: 2017 / Funda??o de Amparo ? Pesquisa do estado de Minas Gerais (FAPEMIG) / Investigar as rela??es ecol?gicas entre esp?cies simp?tricas e suas intera??es com o habitat, s?o importantes para a compreens?o dos mecanismos que controlam a estrutura da comunidade ecol?gica. Entretanto, informa??es a respeito dos mecanismos que permitam a coexist?ncia entre mam?feros simp?tricos s?o ainda escassas. Descrevemos no presente estudo, os padr?es de dieta dos carn?voros simp?tricos Chironectes minimus e Lontra longicaudis, analisamos os poss?veis mecanismos de particionamento de recursos entre essas esp?cies, a partir das dimens?es de nicho alimentar, temporal e espacial e discutimos o potencial para intera??es interespec?ficas, como a competi??o e preda??o. Os h?bitos alimentares dos carn?voros foram estudados a partir das an?lises de amostras de fezes coletadas entre novembro de 2008 e fevereiro de 2012, em fragmentos de Mata Atl?ntica no arroio Morungava, localizado no munic?pio de Gravata?, Rio Grande do Sul, Brasil. Foram coletadas 85 amostras de C. minimus e 21 amostras de Lontra longicaudis, distribu?das entre 23 latrinas encontradas ao longo das margens direita e esquerda do arroio. A cu?ca d??gua e a lontra neotropical apresentaram h?bitos alimentares especialistas, por?m, com dietas distintas, especialmente com rela??o as preferencias alimentares e ? frequ?ncia dos itens consumidos, o que provavelmente se reflete no baixo ?ndice de sobreposi??o de nicho tr?fico entre as esp?cies. Chironectes minimus apresentou uma dieta primordialmente carnivora, no entanto, bastante diversificada, consumindo principalmente crust?ceos dec?podos (100%), insetos (69%) e peixes (40%), enquanto L. longicaudis apresentou uma dieta baseada principalmente no consumo de peixes (95%), seguidos por insetos (71%), e anf?bios anuros (67%). Observamos um padr?o de segrega??o espacial e temporal entre a cu?ca d??gua e a lontra neotropical na ?rea de estudo, embora, evid?ncias demonstrem que essas esp?cies coexistem em algum momento, tanto no espa?o quanto no tempo, j? que, registramos a preda??o da cu?ca d??gua pela lontra neotropical. Este ? o primeiro estudo de particionamento de recursos entre C. minimus e L. longicaudis, fornecendo informa??es importantes sobre os h?bitos alimentares destes mam?feros semiaqu?ticos e sobre os mecanismos ecol?gicos respons?veis pela estrutura desta guilda de carn?voros na Mata Atl?ntica. / Disserta??o (Mestrado) ? Programa de P?s-gradua??o em Biologia Animal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2017. / Investigate the ecological relationships between sympatric species and their interactions with the habitat are important for understanding the mechanisms that control the structure of ecological communities. However, informations regarding the mechanisms that allow the coexistence among sympatric mammals are still scarce. Here we described the feeding habits of two sympatric carnivores, Chironectes minimus and Lontra longicaudis, analyzed the resource partitioning mechanisms investigating different niche dimensions such as feeding, spatial and temporal niches, and also discussed the potential for interspecific interactions, such as intrespecific competition and predation. The feeding habits were studied from the analysis of fecal samples collected between November 2008 and February 2012, in fragments of Atlantic Forest in the Morungava stream, located in the city of Gravata?, Rio Grande do Sul, Brazil. 85 samples of C. minimus and 21 samples of Lontra longicaudis distributed among 23 latrines found along the right and left banks of the stream were collected, Water opossum and Neotropical otter presented specialized food habits, however, with different diets, especially regarding food preferences and frequency of consumed items, which is probably reflected by the slight trophic niche overlap between species. Chironectes minimus presented a primordial carnivorous diet, however, very diversified, consuming decapod crustaceans (100%), insects (69%) and fishes (40%), while L. longicaudis presented a diet based mainly on fish consumption 95%), followed by insects (71%), and anuran amphibians (67%). We observed a spatial and temporal segregation pattern among the water opossum and the Neotropical otter in the study site, although, evidences show that these species coexist at some time, both in space and time, since we recorded the predation of the water opossum by the Neotropical otter. This is the first study of resource partitioning among C. minimus and L. longicaudis, providing significant information about the feeding habits of these semi-aquatic mammals and about the ecological mechanisms responsible for the structure of this carnivorous guild in Atlantic Forest.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-08-25T20:22:44Z No. of bitstreams: 1 FuadMousseAbinaderJunior_TESE.pdf: 4950058 bytes, checksum: 8b460657822556678edafea893ba0d36 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-08-25T21:57:31Z (GMT) No. of bitstreams: 1 FuadMousseAbinaderJunior_TESE.pdf: 4950058 bytes, checksum: 8b460657822556678edafea893ba0d36 (MD5) / Made available in DSpace on 2016-08-25T21:57:31Z (GMT). No. of bitstreams: 1 FuadMousseAbinaderJunior_TESE.pdf: 4950058 bytes, checksum: 8b460657822556678edafea893ba0d36 (MD5) Previous issue date: 2015-08-21 / A crescente demanda por tr?fego de dados em redes de acesso de banda larga sem fio ? Internet requer tanto o desenvolvimento de novas tecnologias de acesso mais eficientes quanto que novas faixas de frequ?ncia do espectro eletromagn?tico sejam alocadas para este fim. A introdu??o de um grande n?mero de small cells em redes celulares aliado ? ado??o de forma complementar de tecnologias de Wireless Local Area Networks (WLAN) em faixas de espectro n?o-licensiadas tem se verificado como um dos conceitos mais promissores. Uma das alternativas dentro deste conceito ? a introdu??o de small cells Long Term Evolution (LTE) operando em espectro n?o-licensiado Industrial, Science and Medical (ISM) de 5Gigahertz (GHz), numa abordagem conhecida como Unlicensed LTE (LTE-U). No entanto, a tecnologia de acesso de banda larga sem fio IEEE 802.11 (Wi-Fi) j? se encontra bastante difundida e operando nessa faixa de espectro, o que pode acarretar problemas de desempenho derivados da coexist?ncia de ambas as tecnologias na mesma faixa de espectro. Al?m disso, existe a necessidade de melhorar a opera??o do Wi-Fi para que possa suportar cen?rios com um grande n?mero de redes vizinhas, cada uma com um grande n?mero de n?s (conhecido como "?implanta??o densa"?). ? sabido que o desempenho global das redes Wi-Fi cai de forma acentuada com o aumento de n?mero de d?s compartilhando o canal, e portanto mecanismos para aumentar sua efici?ncia espectral se fazem necess?rios. Este trabalho ? dedicado ao problema da coexist?ncia entre diferentes sistemas de acesso ? banda larga sem fio operando nas mesmas faixas de espectro n?o-licensiado, e como resolver esses problemas por meio de algoritmos de coordena??o distribu?dos. O problema da coexist?ncia entre redes diferentes (i.e. LTE e Wi-Fi) e o problema de coexist?ncia entre diferentes redes da mesma tecnologia (i.e. m?ltiplas Overlapping Basic Subscriber Sets (OBSSs) Wi-Fi) ? analisado qualitativamente e quantitativamente via simula??o sist?mica, e suas principais quest?es a serem enfrentadas s?o identificadas. Com base nisso, solu??es distribu?das de coordena??o s?o propostas e avaliadas via simula??o sist?mica tanto para o problema de coexist?ncia inter-tecnologias como para o problema de coexist?ncia intra-tecnologia. Os resultados das avalia??es indicam que as solu??es concebidas prov?m ganhos significativos ante uma situa??o de coexist?ncia sem coordena??o distribu?da. / The increasing demand for Internet data traffic in wireless broadband access networks requires both the development of efficient, novel wireless broadband access technologies and the allocation of new spectrum bands for that purpose. The introduction of a great number of small cells in cellular networks allied to the complimentary adoption of Wireless Local Area Network (WLAN) technologies in unlicensed spectrum is one of the most promising concepts to attend this demand. One alternative is the aggregation of Industrial, Science and Medical (ISM) unlicensed spectrum to licensed bands, using wireless networks defined by Institute of Electrical and Electronics Engineers (IEEE) and Third Generation Partnership Project (3GPP). While IEEE 802.11 (Wi-Fi) networks are aggregated to Long Term Evolution (LTE) small cells via LTE / WLAN Aggregation (LWA), in proposals like Unlicensed LTE (LTE-U) and LWA the LTE air interface itself is used for transmission on the unlicensed band. Wi-Fi technology is widespread and operates in the same 5 GHz ISM spectrum bands as the LTE proposals, which may bring performance decrease due to the coexistence of both technologies in the same spectrum bands. Besides, there is the need to improve Wi-Fi operation to support scenarios with a large number of neighbor Overlapping Basic Subscriber Set (OBSS) networks, with a large number of Wi-Fi nodes (i.e. dense deployments). It is long known that the overall Wi-Fi performance falls sharply with the increase of Wi-Fi nodes sharing the channel, therefore there is the need for introducing mechanisms to increase its spectral efficiency. This work is dedicated to the study of coexistence between different wireless broadband access systems operating in the same unlicensed spectrum bands, and how to solve the coexistence problems via distributed coordination mechanisms. The problem of coexistence between different networks (i.e. LTE and Wi-Fi) and the problem of coexistence between different networks of the same technology (i.e. multiple Wi-Fi OBSSs) is analyzed both qualitatively and quantitatively via system-level simulations, and the main issues to be faced are identified from these results. From that, distributed coordination mechanisms are proposed and evaluated via system-level simulations, both for the inter-technology coexistence problem and intra-technology coexistence problem. Results indicate that the proposed solutions provide significant gains when compare to the situation without distributed coordination.

Made available in DSpace on 2014-12-17T14:33:05Z (GMT). No. of bitstreams: 1 HeitorBAS_DISSERT.pdf: 387151 bytes, checksum: a2b73fdba420696aff0ff91c7e9c1bd2 (MD5) Previous issue date: 2012-02-23 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Intending to explain the extraordinary lizard coexistence levels found in Australian deserts, Morton & James (1988) figured out a hypothesis which defends that the termite diversity would bring about lizard radiation. This study aims to verify the validation of that hypothesis in Caatinga lizard assemblages. This study also objectives verifying if the termite defense mechanisms influence their consuming levels by lizards and if this pattern differs between different lizard lineages. Termites were collected using a standardized sampling protocol of termites. Besides using haphazard sampling, we collect lizards with 108 pitfall traps in each area. Intending to check the linkage between the termite and lizard assemblages, the lizard stomach contents were analyzed and then a canonical correspondence analysis was performed. The presence of nonrandom patterns of diet overlap among the lizard species was also examined. Aiming to check if the defense mechanisms of termite influence their consuming pattern by lizards it was performed a laboratory experiment where termite with different defense mechanisms were offered to lizards of two different lineages. We verified that lizard assemblages do not consume termites according to termite abundance in ecosystems. Furthermore, mean niche overlap lizard species did not differ significantly from that expected by chance. We found that termite chemical defense mechanism does influence the termite s pattern consuming by lizards. These results do not corroborate premises which support Morton & James hypothesis (1988) and point out that lizard do not chose termites based on their abundance, but, trying to avoid consuming termites which exhibit chemical defense mechanisms. This defense mechanism, however, may not be the only explanation to patterns of termite s consuming by lizards. / Ao tentar explicar a extraordin?ria taxa de coexist?ncia de lagartos em desertos Australianos, Morton & James (1988) formularam uma hip?tese em que a diversidade de t?rmitas promoveria uma diversifica??o dos lagartos. O presente estudo visa verificar se essa hip?tese ? v?lida para as taxocenoses de lagartos da Caatinga. Objetiva-se tamb?m verificar se os mecanismos de defesa dos t?rmitas influenciam a taxa com que esses s?o consumidos pelos lagartos e se esse padr?o difere entre diferentes linhagens de lagartos. Para a coleta dos t?rmitas foi aplicado um protocolo padronizado de amostragem term?tica. Para a coleta dos lagartos, al?m da busca ativa, foram instaladas 108 armadilhas de queda em cada ?rea. Para verificar a rela??o entre as taxocenoses de lagartos e t?rmitas foi analisado o conte?do estomacal dos lagartos e, em seguida, foi realizada uma An?lise de Correspond?ncia Can?nica. Posteriormente realizou-se uma an?lise de sobreposi??o de nicho. Para verificar se o mecanismo de defesa dos t?rmitas influencia o seu padr?o de consumo pelos lagartos, realizou-se um experimento onde se ofertou t?rmitas com diferentes mecanismos de defesa para lagartos de duas linhagens diferentes. Verificou-se que a taxocenose de lagartos n?o consome os t?rmitas de acordo com a abund?ncia destes no ecossistema. Al?m disso, a sobreposi??o de nicho alimentar n?o foi menor do que o esperado ao acaso. Verificou-se que o mecanismo de defesa qu?mica influencia sim o padr?o de consumo dos t?rmitas pelos lagartos. Esses resultados n?o corroboram as premissas que alicer?am a hip?tese de Morton & James (1988) e indicam que os lagartos n?o selecionam os t?rmitas a serem consumidos devido ? sua abund?ncia, mas, sim, de modo a evitar t?rmitas que exibissem mecanismos de defesa qu?mica. A presen?a desse mecanismo de defesa, por?m, parece n?o ser a ?nica explica??o para o padr?o de consumo dos t?rmitas pelos lagartos.

Made available in DSpace on 2014-12-17T14:33:09Z (GMT). No. of bitstreams: 1 KarolLBOF_DISSERT_PARCIAL.pdf: 340660 bytes, checksum: f2a188d52831a6a40d06910a31049e94 (MD5) Previous issue date: 2012-07-05 / How ecologically similar species are able to coexist has always generated great interest in the scientific community. Classical niche theory predicts that species coexistence is only possible when they segregate in at least one dimension of the ecological niche, thus leading to ecological differentiation among species. However, recent work has shown that species that are more similar in some ecological traits are the ones more prone to be able to coexist (environmental filter). The knowledge of how these forces act shaping ecological communities can reveal co-existence strategies, providing important information for management and conservation of the species. This study tested these hypotheses using a pair of coexisting species of Herpsilochmus, H. pectoralis and H. sellowi. In this study I use high resolution (50 x 50 m) ecological niche models to Identify which environmental factors best predict species occurrence. Next, I calculate the overlap in habitat use by species and build null models to test the hypothesis of spatial niche segregation. In addition, I obtain the selectivity parameters of habitat use to test whether the species H. pectoralis (larger body size) is less selective than H. sellowi (smaller body size) as stated in the literature for other species. The results reject the ecological equivalence among species, revealing that the species of Herpsilochmus explore the habitat differently, having different environmental niches. The hypothesis of environmental filter was not observed in my analysis, the observed overlap in habitat use among species was lower than expected by chance. Evidence that Herpsilochmus are spatially segregating reinforces the hypothesis of interspecific competition as the predominant force in the selection of microhabitat of the species. However, more data and experiments are necessary to state categorically that the observed pattern is a result of current or past competition / Como esp?cies similares ecologicamente s?o capazes de coexistir sempre gerou grande interesse na comunidade cient?fica. A teoria cl?ssica de nicho prev? que para que a coexist?ncia seja poss?vel as esp?cies devem segregar em alguma dimens?o do nicho ecol?gico, portanto levando a diferencia??o entre as esp?cies. No entanto, trabalhos recentes tem demonstrado que justamente esp?cies mais similares em algumas caracter?sticas ecol?gicas seriam mais capazes de coexistir (filtro ambiental). O conhecimento de como essas for?as atuam nas comunidades pode revelar estrat?gias de coexist?ncia, trazendo importantes informa??es para o manejo e conserva??o das esp?cies. Neste estudo testei essas hip?teses de coexist?ncia utilizando o par de esp?cies Herpsilochmus pectoralis e H. sellowi. Para isso utilizei modelos de nicho ecol?gico em alta resolu??o (50 x50 m).Identifiquei quais os fatores ambientais estudados melhor predizem a ocorr?ncia das esp?cies. Em seguida, calculei a sobreposi??o no uso de h?bitat pelas esp?cies e constru? modelos nulos para testar a hip?tese de segrega??o de nicho espacial. Ainda, calculei par?metros de seletividade do uso do h?bitat para testar se a esp?cie H. pectoralis (esp?cie de maior tamanho de corpo) ? menos seletiva que o H. sellowi (esp?cie de menor tamanho de corpo) como previsto na literatura para outras esp?cies.Os resultados rejeitam a equival?ncia ecol?gica entre as esp?cies, revelando que as esp?cies de Herpsilochmus exploram o habitat de forma diferenciada, possuindo nichos ambientais distintos. A hip?tese de filtro ambiental n?o foi evidenciada em nossas an?lises, sendo a sobreposi??o no uso do h?bitat observada entre as esp?cies menor do que o esperado ao acaso. Evid?ncias de que os Herpsilochmus est?o segregando espacialmente refor?a a hip?tese da competi??o interespec?fica como for?a predominante na sele??o de microh?bitat das esp?cies. No entanto, para afirmar categoricamente que o padr?o observado ? efeito de uma competi??o atual ou passada experimentos futuros s?o sugeridos

Submitted by Ricardo Cedraz Duque Moliterno (ricardo.moliterno@uefs.br) on 2016-03-12T00:12:47Z No. of bitstreams: 1 Disserta??o - C?ssia Alves de S?.pdf: 408040 bytes, checksum: a24d9c29b600bca2f7903bdca077b81c (MD5) / Made available in DSpace on 2016-03-12T00:12:47Z (GMT). No. of bitstreams: 1 Disserta??o - C?ssia Alves de S?.pdf: 408040 bytes, checksum: a24d9c29b600bca2f7903bdca077b81c (MD5) Previous issue date: 2013-03-21 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The daily activity pattern of social wasps can be influenced by different mechanisms such as environmental restrictions or interspecific interactions. However, the importance of interspecific interactions on the determination of the daily activity patterns may decrease on habitats with high environmental complexity. In this sense, we evaluated two hypotheses in order to understand what factors affect the daily activity patterns of social wasps: 1) The abundance overlap of different species during the day is lower when environmental complexity is greater, and 2) Thermal restrictions may constrain wasp activity. We counted the abundance of several wasp species foraging throughout the day on extrafloral nectaries in two plantations of caupi bean: on esurrounded by a pasture matrix (low structural complexity) and the other surrounded by fruit trees (high structural complexity). Afterwards, we evaluated the abundance overlap during the day, the abundance variations per hour and the preferential time of start and end of day activity. Temporal overlapping between species during the day was high for both plantations. The majority of species had a bimodal abundance pattern, with one abundance peak during the morning and the other during the afternoon. Species of major size started their activity during later hours, while species of minor size were active on every hour. These results indicate two scenarios: first, competition seems to below in these communities and second, temperature seems to be particularly restrictive for the activity of species of greater size. / A coleta de recursos gluc?dios pelas vespas sociais ao longo do dia pode variar como resposta a diferentes mecanismos, podendo responder a restri??es ambientais ou a intera??es interespec?ficas. Por?m, a import?ncia relativa das intera??es interespec?ficas pode ser reduzida em sistemas com maior complexidade ambiental. Para compreender esse efeito, avaliamos as seguintes hip?teses: 1) A sobreposi??o nos hor?rios de forrageamento das esp?cies de vespas sociais ao longo do dia ? menor quando a complexidade ambiental ? maior e 2) o padr?o de atividade di?rio das vespas ao longo do dia ? determinado por restri??es ambientais. Para isso, quantificamos a abund?ncia de diferentes esp?cies de vespas sociais forrageando em nect?rios extraflorais em duas planta??es de do feij?o caupi: uma circundada por matriz de pasto (baixa complexidade estrutural) e outra por frut?feras (alta complexidade estrutural). Iniciamos as observa??es e coletas ao longo do dia, depois que os NEFs do feij?o estavam ativos, e avaliamos o padr?o de sobreposi??o temporal de abund?ncia, o padr?o de abund?ncia em cada hor?rio, bem como a rela??o entre o hor?rio de in?cio e fim de atividade e o tamanho de cada esp?cie. A sobreposi??o temporal foi alta para as duas ?reas. O padr?o de abund?ncia foi bimodal ao longo do dia. As esp?cies de maior tamanho entraram em atividade em hor?rios mais tardios enquanto as esp?cies de pequeno tamanho n?o apresentaram um padr?o de inicio e fim de atividade. Esses resultados indicam que a competi??o entre esp?cies de vespas sociais ? baixa, permitindo a alta sobreposi??o do hor?rio de atividade nas duas ?reas. J? a temperatura parece restringir o hor?rio de atividade para vespas de grande porte.