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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Efeitos da fragmenta??o de h?bitat sobre borboletas frug?voras (Lepidoptera: Nymphalidae) em remanescentes de Mata Atl?ntica no Rio Grande do Norte

Brito, Marcos Roberto Monteiro de 23 February 2017 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-07-04T13:34:27Z No. of bitstreams: 1 MarcosRobertoMonteiroDeBrito_DISSERT.pdf: 1200664 bytes, checksum: 855d06a14e56c6a1a0d86a0597cc261e (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-07-12T14:08:35Z (GMT) No. of bitstreams: 1 MarcosRobertoMonteiroDeBrito_DISSERT.pdf: 1200664 bytes, checksum: 855d06a14e56c6a1a0d86a0597cc261e (MD5) / Made available in DSpace on 2017-07-12T14:08:35Z (GMT). No. of bitstreams: 1 MarcosRobertoMonteiroDeBrito_DISSERT.pdf: 1200664 bytes, checksum: 855d06a14e56c6a1a0d86a0597cc261e (MD5) Previous issue date: 2017-02-23 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / A perda de h?bitat e a fragmenta??o est?o entre as maiores amea?as a biodiversidade, podendo levar a decl?nios de comunidades biol?gicas. As respostas a essas perturba??es dependem de fatores da paisagem e tamb?m de fatores intr?nsecos aos fragmentos, al?m de poderem ser diferentes entre esp?cies. O presente trabalho avalia como a ?rea do fragmento, isolamento, forma, qualidade da matriz e a dist?ncia para o curso de ?gua permanente (rio ou lago) mais pr?ximo afetam a riqueza e a abund?ncia de borboletas frug?voras em fragmentos de Mata Atl?ntica no nordeste brasileiro. O estudo foi realizado em 15 fragmentos com ?reas entre 1,7 e 27,4 hectares, inseridos em uma matriz dominada por planta??es de cana-de-a??car e distantes da ?gua entre 0 e cerca de 2000 metros. A riqueza de esp?cies e abund?ncia declinaram com o aumento da dist?ncia para ?gua. A sele??o de modelos sugeriu que a dist?ncia para ?gua ? o principal fator influenciando riqueza e abund?ncia, mas qualidade da matriz tamb?m apareceu como importante fator para a riqueza, enquanto forma do fragmento aparece como fator importante para abund?ncia. Nossos resultados destacam a import?ncia da dist?ncia para um curso de ?gua na manuten??o de comunidades de borboletas frug?voras em ambientes fragmentados de Mata Atl?ntica. / Habitat loss and fragmentation are the biggest threats to biodiversity, contributing to declines in biological communities. The response of species and communities to these disturbances depend on landscape features and characteristics of each fragment, and can also vary among different species. Our study test how fragment area, isolation, shape, matrix quality and distance to the nearest permanent course of water (river or pond) affect fruit-feeding butterfly communities in the northeastern portion of the Brazilian Atlantic Forest. We used 15 fragments, surrounded by a heterogeneous matrix, consisting predominantly of sugarcane crop fields, ranging from 1,7 to 27,4 hectares, spread in distance classes to a permanent course of water ranging from zero to 2000 meters. Species richness and abundance decreased with increased distance to water. Model selection suggested distance to the water as the main factor affecting species richness and abundance, but matrix quality is also an important predictor for species richness, while fragment shape is important for abundance. Our results highlight the importance of distance to a water course in maintaining fruit-feeding butterflies communities in fragmented landscapes in the Atlantic Forest.
42

Efeitos dos ninhos de Atta sexdens (Linnaeus, 1758) (Hymenoptera: Formicidae) sobre a estrutura da comunidade de artr?podes do solo na Mata Atl?ntica / Nests effects of Atta sexdens (LINNAEUS, 1758) (Hymenoptera:Formicidae) on arthropod community structure of soil in Atlantic Forest.

Oliveira, Marina Vasconcelos de 13 February 2017 (has links)
Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2017-07-27T13:09:11Z No. of bitstreams: 1 2017 - Marina Vasconcelos de Oliveira.pdf: 1221503 bytes, checksum: 9381f92942c7388888364c8566c8a781 (MD5) / Made available in DSpace on 2017-07-27T13:09:11Z (GMT). No. of bitstreams: 1 2017 - Marina Vasconcelos de Oliveira.pdf: 1221503 bytes, checksum: 9381f92942c7388888364c8566c8a781 (MD5) Previous issue date: 2017-02-13 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Tropical forests support a great vegetal diversity, in part, through an nutrient cycling initiated by the soil arthropod?s fauna, which facilitated the litter decomposers action, propitiating the release of stock nutrients to the soil. Therefore, studies about these fauna and what factors alter it are extremely important to understand the nutrient cycling process in tropical forests. Among epigeic fauna represents, the leaf-cutting ants are considered the Neotropical region dominant herbivores and studies relate their multiple effects on vegetable community and the soil . Nonetheless, there aren?t studies about leaf-cutting ants effects on other arthropods communities, including mirmecofauna. This study aim to investigate the nests effects of the leaf-cutting ant Atta sexdens (Linnaeus, 1758) (Formicidae: Myrmicinae) on a soil arthropod community. The study site was Reserva Ecol?gica de Guapia?u, Cachoeiras de Macacu, Rio de Janeiro, Brazil, where we collected samples at ten A. sexdens nests in period of 2 February to 9 February 2016. Along a linear transect of 32 meters, we collected litter samples from 0,25 m? size at intervals of 8 meters from each nests? edge of A. sexdens, whereby we also measured the air and soil temperature, the light and the air relative humidity. We aim to verify if litter structure and microclimatic conditions alter arthropod community structure and if these effects can be mediated by A. sexdens nests. The hypothesis in question are: 1) Litter Hypothesis, whereby arthropod community structure would be influenced by litter and litter would be altered by A. sexdens; 2) Abiotic Factors Hypothesis, whereby arthropod community structure would be influenced by abiotic factors and these factors would be altered by A. sexdens and 3) Nest Hypothesis, whereby community alterations would happen through intrinsic factors to active nests presence and not explained by alterations in a litter and/or in abiotic factors measured. For the test of the first and the second hypothesis, we did simple regressions and next variance analysis, assessing the litter and abiotic factors effects on arthropod community parameters and if this effects can be mediated by A. sexdens. To test Nest Hypothesis, we did variance analysis and analysis of similarities, assessing direct effects of A. sexdens on other arthropods community. We collected 3074 arthropods, among them Acari and Collembola were the most abundant groups. In relation of the ants, we obtained 63 specimens, in 26 genera and 32 identified species. The Strumigenys genus was one of the most frequent genera and it detained the biggest richness among mirmecofauna predators.We didn?t detect A. sexdens effects on soil arthropod community around its nests. Studies that include sazonality and behavior comparison between different species of leaf-cutting ants can result in new knowledge about the interaction between these organisms and other arthropods / As florestas tropicais sustentam uma grande diversidade vegetal, em parte, devido ? ciclagem de nutrientes iniciada pela fauna de artr?podes do solo, que facilita a a??o dos decompositores da serrapilheira, propiciando a libera??o dos nutrientes estocados para o solo. Logo, estudos sobre essa fauna e que fatores a afetam s?o importantes para a compreens?o dos processos de ciclagem de nutrientes em florestas tropicais. Dentre os representantes da fauna epigeica, as formigas-cortadeiras s?o consideradas os herb?voros dominantes da regi?o Neotropical e estudos relatam seus m?ltiplos efeitos sobre a comunidade vegetal e o solo. Entretanto, n?o h? estudos sobre os efeitos das formigas-cortadeiras sobre a comunidade dos demais artr?podes. Este estudo visa investigar os efeitos dos ninhos de formigas-cortadeiras Atta sexdens (Linnaeus, 1758) (Formicidae: Myrmicinae) sobre a comunidade de artr?podes do solo. A ?rea de estudo foi a Reserva Ecol?gica de Guapia?u, munic?pio de Cachoeiras de Macacu, Rio de Janeiro, Brasil, na qual coletamos amostras em 10 ninhos de A. sexdens no per?odo de 2 a 9 de fevereiro de 2016. Ao longo de um transecto linear de 32 metros, coletamos amostras de serrapilheira de tamanho 0,25m? a intervalos de 8 metros a partir da borda de cada ninho de A. sexdens, nos quais tamb?m medimos as temperaturas do ar e do solo, a luz e a umidade relativa do ar. Objetivamos averiguar se a estrutura da serrapilheira e as condi??es microclim?ticas alteram a estrutura da comunidade de artr?podes e se esses efeitos podem ser mediados pelos ninhos de A. sexdens. As hip?teses em estudo s?o: 1) Hip?tese da Serrapilheira, na qual a estrutura da comunidade de artr?podes seria influenciada pela serrapilheira e a serrapilheira seria alterada por A. sexdens; 2) Hip?tese dos Fatores Abi?ticos, na qual a estrutura da comunidade de artr?podes seria influenciada pelos fatores abi?ticos locais e estes fatores seriam alterados por A. sexdens e 3) Hip?tese do Ninho, em que as altera??es na comunidade se dariam por fatores intr?nsecos ? presen?a dos ninhos ativos e n?o explicados por altera??es na serrapilheira e/ou nos fatores abi?ticos medidos. As duas primeiras hip?teses foram testadas atrav?s de regress?es lineares simples, seguidas de an?lises de vari?ncia, avaliando os efeitos da serrapilheira e dos fatores abi?ticos sobre os par?metros da comunidade de artr?podes e se esses efeitos podem ser mediados por A. sexdens. No teste da hip?tese do Ninho, fizemos an?lises de vari?ncia e an?lises de similaridade, avaliando os efeitos diretos de A. sexdens sobre a comunidade dos demais artr?podes. Coletamos 3074 artr?podes, dentre os quais Acari e Collembola foram os grupos mais abundantes. Em rela??o ?s formigas, obtivemos 63 morfoesp?cies, em 26 g?neros e 32 esp?cies identificadas. O g?nero Strumigenys foi um dos g?neros mais frequentes e deteve a maior riqueza dentre os predadores da mirmecofauna. N?o detectamos efeitos de A. sexdens sobre a comunidade de artr?podes do solo do seu entorno. Estudos que incluam a sazonalidade e que comparem o comportamento entre diferentes esp?cies de formigas-cortadeiras podem resultar em novos conhecimentos a respeito da intera??o desses organismos com os demais artr?podes
43

Evaluation on how suitable open source tools are for model to model transformation : An industrial point of view

Márki, András January 2013 (has links)
Model-Driven Development can improve the development process, but it needs tools for model transformation. For industrial companies, the most important aspect is that the transformation tools should scale well, so that they can be used with huge models. There are some open-source model transformation tools on the market, and this report aims to investigate the scalability of open source tools for model transformation. For the investigation, Eclipse Modeling Framework is used. This report identifies four open-source model transformation tools (ATL, QVT Operational, QVT Declarative, SmartQVT) and identifies the variables needed for a tool to be evaluated within the bounds of an experiment. The only tool which could be benchmarked was ATL, which scaled linearly in both terms of transformation time and memory consumption.
44

Role Of Host Immune Response And Bacterial Autolysin Atl In Human Nasal Colonization By Staphylococcus Aureus

Paramanandam, Vanathy 01 January 2013 (has links)
Staphylococcus aureus (SA) is a major human pathogen that colonizes the anterior nares in 30% of the human population. Though nasal carriage of SA is a known risk factor for the subsequent spread of SA infections, the dynamics of SA nasal colonization is poorly understood. Our research focuses on understanding the host and bacterial factors that might contribute to the human nasal colonization by SA. In an attempt to elucidate the host response to SA, we performed an autologous human in vivo nasal colonization study, which showed decreased survival rates of SA in hosts who elicited a robust immune response. We also identified a significant correlation between SA nasal colonization and the expression of host proinflammatory, chemotactic and growth factors. Additionally, we functionally disrupted a major autolysin, atl a surface expressed bacterial protein that plays multiple roles in cell separation, adhesion and biofilm formation of SA. Microscopic analysis of the ∆atl strains showed phenotypic differences, including cell clumping and cluster formation due to defective cell separation, which confirmed the functional loss of atl. Subsequent analysis of the ∆atl and wild-type strains revealed that there was no significant difference in their ability to adhere to human nasal epithelial cells (hNEC) in an ex vivo hNEC model. Similarly, our competitive in vivo human nasal colonization study, in which equal colony-forming units of each wild-type and ∆atl SA strain were inoculated in the anterior nares of donors, showed similar survival rates between wild-type and ∆atl. These results suggest that Atl might not be directly involved in the adherence and colonization of SA to the anterior nares. Furthermore, our study suggests that host factors might play a predominant role in determining SA colonization to human anterior nares.
45

Identification of HTLV-1 Tax-1 and HBZ Binding Partners, and Their Role in HTLV-1 Biology and Pathogenesis

Al-Saleem, Jacob Jamal January 2016 (has links)
No description available.
46

Measles Virotherapy in Adult T cell Leukemia

Machado Parrula, Maria Cecilia January 2009 (has links)
No description available.
47

BTL marketingové komunikační aktivity jako stimul k nákupu, aplikace na značku Coca Cola. / BTL marketing communications as an incitement to the purchase, applied to Coca-Cola brand

Mahdalová, Renata January 2010 (has links)
The thesis consists of theoretical and practical part. In the theoretical part important terms like marketing mix, marketing communications, target group and marketing goals are explained. There are also described the individual marketing tools of the marketing mix, which are divided into ATL and BTL marketing tools. The whole thesis is focused on BTL marketing activities like sales promotion, direct marketing and new media. The practical part includes the case study about BTL activities of the company Coca-Cola HBC Česká republika. There is a detailed description of the currently released communication campaign of the new flawoured water Bonaqua. The objektive of the thesis is to point out that BTL activities are more effective when trying to influence the customer and to demonstrate the increasing significance of BTL marketing activities.
48

Model-Driven requirements engineering process aided by ontologies and natural controlled languages

Cobe, Raphael Mendes de Oliveira 29 June 2009 (has links)
Made available in DSpace on 2014-12-17T15:47:51Z (GMT). No. of bitstreams: 1 RaphaelMOCpdf.pdf: 3833849 bytes, checksum: fc73f8956766c49a68d58575132da8f2 (MD5) Previous issue date: 2009-06-29 / Researches in Requirements Engineering have been growing in the latest few years. Researchers are concerned with a set of open issues such as: communication between several user profiles involved in software engineering; scope definition; volatility and traceability issues. To cope with these issues a set of works are concentrated in (i) defining processes to collect client s specifications in order to solve scope issues; (ii) defining models to represent requirements to address communication and traceability issues; and (iii) working on mechanisms and processes to be applied to requirements modeling in order to facilitate requirements evolution and maintenance, addressing volatility and traceability issues. We propose an iterative Model-Driven process to solve these issues, based on a double layered CIM to communicate requirements related knowledge to a wider amount of stakeholders. We also present a tool to help requirements engineer through the RE process. Finally we present a case study to illustrate the process and tool s benefits and usage / Pesquisas em Engenharia de Requisitos tem crescido ao longo dos ?ltimos anos. Pesquisadores est?o preocupados com uma s?rie de problemas em aberto como: comunica??o entre diversos perfıs envolvidos na engenharia de requisito; problemas na defini??o de escopo; problemas de volatilidade e ratreabilidade de requisitos. Para lidar com este conjunto de problemas em aberto, um conjunto de trabalhos est?o concentrados em (i) definir processos para coletar especifica??es de clientes para lidar com prolemas de escopo; (ii) definir modelos para representar requisitos para lidar com problemas de comunica??o e rastreabilidade; e (iii) defini??o de mecanismos e processos para serem aplicados a modelagem de requisitos para facilitar a evolu??o e manuten??o de requisitos, lidando com problemas de volatilidade e rastreabilidade em requisitos. Neste trabalho ? proposto um processo dirigido por modelo para solucionar estes problemas em aberto. Este processo ? baseado na ideia de um CIM dividido em duas camadas de forma que se consiga difundir o conhecimento relacionado ao requisitos para um n?mero maior de stakeholders. Durante este trabalho tamb?m foi desenvolvida uma ferramenta que tem como objetivo auxiliar a execu??o de tal processo. Por fim apresentamos um estudo de caso para ilustrar os benef?cios do uso da ferramenta e do processo
49

Dos requisitos ? arquitetura em linhas de produtos de software: uma estrat?gia de transforma??es entre modelos

Coelho, Keivilany Janielle de Lima 06 February 2012 (has links)
Made available in DSpace on 2014-12-17T15:47:59Z (GMT). No. of bitstreams: 1 KeivilanyJLC_DISSERT.pdf: 3136956 bytes, checksum: 58f2931b21ff1ab0cd5e4e065e0d1aa4 (MD5) Previous issue date: 2012-02-06 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The tracking between models of the requirements and architecture activities is a strategy that aims to prevent loss of information, reducing the gap between these two initial activities of the software life cycle. In the context of Software Product Lines (SPL), it is important to have this support, which allows the correspondence between this two activities, with management of variability. In order to address this issue, this paper presents a process of bidirectional mapping, defining transformation rules between elements of a goaloriented requirements model (described in PL-AOVgraph) and elements of an architectural description (defined in PL-AspectualACME). These mapping rules are evaluated using a case study: the GingaForAll LPS. To automate this transformation, we developed the MaRiPLA tool (Mapping Requirements to Product Line Architecture), through MDD techniques (Modeldriven Development), including Atlas Transformation Language (ATL) with specification of Ecore metamodels jointly with Xtext , a DSL definition framework, and Acceleo, a code generation tool, in Eclipse environment. Finally, the generated models are evaluated based on quality attributes such as variability, derivability, reusability, correctness, traceability, completeness, evolvability and maintainability, extracted from the CAF? Quality Model / O rastreamento entre modelos das atividades de requisitos e arquitetura ? uma estrat?gia que busca evitar a perda de informa??es, reduzindo o gap entre essas duas atividades iniciais do ciclo de vida do software. No contexto das Linhas de Produto de Software (LPS), ? importante que haja um suporte a esse rastreamento, que permita a correspond?ncia entre as duas atividades, com um gerenciamento satisfat?rio das variabilidades. Buscando atender a essa quest?o, este trabalho apresenta um processo de mapeamento bi-direcional, definindo regras de transforma??o entre elementos de modelo de requisitos orientado a objetivos (descrito em PL-AOVgraph) e elementos de descri??o arquitetural (definida em PL-AspectualACME). Essas regras de mapeamento s?o avaliadas em um estudo de caso: a LPS Ginga ForAll. Para automatizar essa transforma??o, implementamos a ferramenta MaRiPLA (Mapping Requirements to Product Line Architecture), atrav?s de t?cnicas do desenvolvimento dirigido a modelos (Model-driven Development MDD), incluindo a linguagem de transforma??es entre modelos Atlas Transformation Language (ATL) com especifica??o de metamodelos do tipo Ecore em conjunto com os frameworks Xtext, de defini??o DSL, e Acceleo, de gera??o de c?digo, em ambiente Eclipse. Por fim, os modelos gerados s?o avaliados, com base em atributos de qualidade como variabilidade, derivabilidade, reusabilidade, corretude, rastreabilidade, completude, evolutibilidade e manutenibilidade, extra?dos do Modelo de Qualidade CAF?
50

Impacts of the Madden-Julian oscillation on intraseasonal precipitation over northeast Brazil

Valad?o, Cati Elisa de Avila 14 August 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-06-10T19:29:13Z No. of bitstreams: 1 CatiElisaDeAvilaValadao_TESE.pdf: 22074758 bytes, checksum: 702cc3f01b20335c0a4d7438f5c6a479 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-13T22:20:59Z (GMT) No. of bitstreams: 1 CatiElisaDeAvilaValadao_TESE.pdf: 22074758 bytes, checksum: 702cc3f01b20335c0a4d7438f5c6a479 (MD5) / Made available in DSpace on 2016-06-13T22:20:59Z (GMT). No. of bitstreams: 1 CatiElisaDeAvilaValadao_TESE.pdf: 22074758 bytes, checksum: 702cc3f01b20335c0a4d7438f5c6a479 (MD5) Previous issue date: 2015-08-14 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / The impacts of the Madden?Julian Oscillation (MJO) on precipitation over Northeast Brazil (NEB, also known as Nordeste) are evaluated based on daily raingauge data from 492 stations over 30-year period (1981-2010). Composites of precipitation, outgoing longwave radiation and moisture-flux anomalies are performed for each phase of the MJO based on the Jones?Carvalho MJO index. To distinguish the MJO signal from other patterns of climate variability, daily data are filtered using a 20 - 90 day band-pass filter; only days classified as MJO events are considered in the composites. A preliminary analysis based on precipitation data was conducted for a small scale area located in NEB?s semiarid interior, in an area known as Serid?. The Serid? is one of the driest regions in NEB, and is recognized by the United Nations Convention to Combat Desertification as particularly vulnerable to desertification. Composites of rainfall anomalies were computed for each of the eight phases of the MJO during February-May, which is Serid??s main rainy season. Results showed that the rainfall patterns in Serid? undergo substantial changes (from enhancement to suppression) as the convective center of the MJO propagates eastward. When combining the MJO signals for wet and dry phases, the difference represents about 50 - 150% modulation of the mean rainfall over Serid?. Then a comprehensive analysis of the role of the MJO in modulating the spatiotemporal variation of NEB?s precipitation was performed, considering all four seasons. The results showed strong seasonality of the MJO impact on precipitation. The most spatially coherent signals of precipitation anomalies occurred in the austral summer, when about 80% of the raingauge stations showed increased precipitation during phases 1 - 2 and suppressed precipitation in phases 5 - 6 of the oscillation. Although the MJO impacts precipitation on intraseasonal timescales in all seasons in most locations, these impacts vary in magnitude and depend on the phase of the oscillation. Precipitation anomalies over NEB are explained by the interaction of convectively coupled Kelvin-Rossby waves with the dominant climatic features in each season. During the austral summer and spring, westerly regimes increased precipitation over most NEB. In the austral winter and fall, precipitation anomalies exhibited more complex spatial variability. In these seasons precipitation anomalies in eastern coastal areas depended on the strength of the South Atlantic anticyclone, which is largely modulated by Rossby waves. The strengthening of the anticyclone intensified the convergence of the trade winds in coastal areas and precipitation windward of the coastal range. Conversely, the intensification of the subsidence was responsible for precipitation deficits in the lee side of the range. These conditions were typically observed when easterly regimes dominate over tropical South America and NEB, decreasing moisture flow from the Amazon. / Este estudo tem como objetivo investigar os impactos da oscila??o de Madden-Julian (OMJ) na precipita??o da regi?o Nordeste do Brasil (NEB). Para tanto foram utilizados dados di?rios de precipita??o baseados em 492 pluvi?metros distribu?dos na regi?o e cobrindo um per?odo de 30 anos (1981 ? 2010). As an?lises atrav?s de composi??es de anomalias de precipita??o, radia??o de onda longa e fluxo de umidade, foram obtidas com base no ?ndice da OMJ desenvolvido por Jones-Carvalho. Para distinguir o sinal da OMJ de outros padr?es de variabilidade clim?tica, todos os dados di?rios foram filtrados na escala de 20 ? 90 dias; portanto somente dias classificados como eventos da OMJ foram considerados nas composi??es. Uma an?lise preliminar baseada apenas nos dados de precipita??o foi feita para uma pequena ?rea localizada no interior semi?rido do NEB, conhecida como Serid?. Essa microrregi?o ? uma das ?reas mais secas do NEB e foi reconhecida pela Conven??o das Na??es Unidas para o Combate ? Desertifica??o e Mitiga??o dos Efeitos das Secas como particularmente vulner?vel ? desertifica??o. Composi??es de anomalias de precipita??o foram feitas para cada uma das oito fases da OMJ durante Fevereiro-Maio (principal per?odo chuvoso da microrregi?o). Os resultados mostraram a exist?ncia de varia??es significativas nos padr?es de precipita??o (de precipita??o excessiva ? deficiente) associados ? propaga??o da OMJ. A combina??o dos sinais de precipita??o obtidos durantes as fases ?midas e secas da OMJ mostrou que a diferen?a corresponde cerca de 50 ? 150% de modula??o das chuvas na microrregi?o. Em seguida, uma investiga??o abrangente sobre o papel da OMJ sobre toda a regi?o Nordeste foi feita considerando-se as quatro esta??es do ano. Os resultados mostraram que os impactos da OMJ na precipita??o intrassazonal do NEB apresentam forte sazonalidade. A maior coer?ncia espacial dos sinais de precipita??o ocorreram durante o ver?o austral, quando cerca de 80% das esta??es pluviom?tricas apresentaram anomalias positivas de precipita??o durante as fases 1 ? 2 da OMJ e anomalias negativas de precipita??o nas fases 5 ? 6 da oscila??o. Embora impactos da OMJ na precipita??o intrassazonal tenham sido encontrados na maioria das localidades e em todas as esta??es do ano, eles apresentaram varia??es na magnitude dos sinais e dependem da fase da oscila??o. As anomalias de precipita??o do NEB observadas s?o explicadas atrav?s da intera??o existente entre as ondas de Kelvin-Rossby acopladas convectivamente e as caracter?sticas clim?ticas predominantes sobre a regi?o em cada esta??o do ano. O aumento de precipita??o observado sobre a maior parte do NEB durante o ver?o e primavera austrais encontra-se associado com o fluxo de umidade de oeste (regime de oeste), o qual favorece a atividade convectiva em amplas ?reas da Am?rica do Sul tropical. Por outro lado, as anomalias de precipita??o durante o inverno e outono austrais apresentaram uma variabilidade espacial mais complexa. Durante estas esta??es, as anomalias de precipita??o observadas nas esta??es localizadas na costa leste do NEB dependem da intensidade do anticiclone do Atl?ntico Sul, o qual ? modulado em grande parte por ondas de Rossby. As caracter?sticas topogr?ficas do NEB parecem desempenhar um papel importante na variabilidade observada na precipita??o, principalmente nestas ?reas costeiras. A intensifica??o do anticiclone aumenta a converg?ncia dos ventos al?sios na costa contribuindo para a ocorr?ncia de precipita??o observada ? barlavento do planalto da Borborema. Por outro lado, o aumento da subsid?ncia parece ser respons?vel pelos d?ficits de precipita??o observados ? sotavento. Tais condi??es mostraram-se t?picas durante o predom?nio do regime de leste sobre a regi?o tropical da Am?rica do Sul e o NEB, durante o qual ocorre uma diminui??o no fluxo de umidade proveniente da Amaz?nia.

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