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Reflexos sociais e impactos territorias: tipologia e espacialização dos equipamentos de cultura e lazer; Social reflex and territorial impact: typology and spatial distribution of cultural and leisure edifications

Nakagawa, Carolina Teixeira
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 11/04/2011 Português
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O presente trabalho pretende analisar a historicidade, a distribuição espacial e a diversidade dos equipamentos de cultura e lazer na cidade de São Paulo, relacionando-os às categorias sociocupacionais da população residente nas áreas em que estão presentes. A metodologia utilizada foi pesquisa bibliográfica, georreferenciamento e análise fatorial por correspondência binária com base no levantamento dos espaços culturais. A pesquisa partiu da noção de patrimônio para a construção de uma tipologia de equipamentos de cultura e lazer. A historicidade de cada tipo foi então relacionada à distribuição espacial deles. Em seguida, analisou-se esta distribuição em relação às categorias sociocupacionais dos residentes, possibilitando a criação de uma tipologia de áreas homogêneas. As concentrações dos equipamentos revelaram uma cidade marcada pela diversidade de centralidades. As noções de patrimônio, de segregações, social e residencial, e de centralidades aparecem como fatores definidores da paisagem. A análise possibilitou verificar, portanto, o adensamento e a diversidade dos equipamentos de cultura e lazer nos quais estão fortemente presentes as camadas superiores e médias da hierarquia social. Isso revelou a ausência de uma única centralidade e a segregação definida também pelos padrões de distribuição do patrimônio de cultura e lazer na cidade de São Paulo.; The present study intends to analyze the historicity...

Soroprevalência, fatores associados e distribuição espacial de infecção por Toxocara spp. em crianças de Acrelândia, Acre, Amazônia Ocidental Brasileira; Seroprevalence, factors associated, and spatial distribution of Toxocara spp. infection in children living in Acrelândia, Acre, Western Brazilian Amazon

Fontoura, Pablo Secato
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 04/04/2012 Português
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A infecção em seres humanos por larvas de nematódeos do gênero Toxocara é uma antropozoonose endêmica em diversas localidades com prevalências superiores a 50% em diferentes grupos populacionais, tanto em países em desenvolvimento como nos desenvolvidos. O presente estudo avaliou a prevalência, fatores associados e distribuição espacial de infecção por Toxocara spp. em crianças residentes na área urbana de Acrelândia, Acre, Amazônia Ocidental Brasileira. Conduziu-se um estudo transversal de base populacional com 1112 crianças <11 anos de idade. Informações socioeconômicas e demográficas foram obtidas por meio de questionário estruturado. Medidas antropométricas e coleta de amostras biológicas (sangue e fezes) foram realizadas pela equipe de pesquisa. A avaliação de soroprevalência da infecção por Toxocara spp. utilizou o método imunoensaio enzimático (ELISA). Registraram-se as coordenadas geográficas pontuais de todos os domicílios participantes do inquérito para análise espacial de varredura. Razões de prevalência (RP; intervalo com 95% de confiança, IC95%) para fatores associados à antropozoonose foram estimadas por regressão de Poisson com seleção hierárquica das variáveis independentes. Verificou-se soroprevalência geral de 38% para anticorpos IgG anti-Toxocara spp.; crianças 5 anos de idade apresentaram maior prevalência para infecção por Toxocara spp....

Spatial distribution of Phyllocnistis citrella Station (Lepidoptera: Gracillariidae) larvae in three scales; Distribuição espacial das larvas de Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae) em três escalas

Jesus, Cristiane Ramos de; Redaelli, Luiza Rodrigues
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Artigo de Revista Científica Formato: application/pdf
Português
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Com o objetivo de determinar a distribuição espacial das larvas de Phyllocnistis citrella Stainton, (Lepidoptera: Gracillariidae), o minador-dos-citros, nas folhas, nos brotos e nas copas das plantas de tangerineira ‘Montenegrina’ (Citrus deliciosa Tenore) e de tangor ‘Murcott’ (Citrus sinensis L. Osbeck x Citrus reticulata Blanco), foram realizadas amostragens quinzenais de julho de 2001 a junho de 2003 em pomares localizados em Montenegro (29° 68’ S e 51° 46’ W), RS, Brasil. Em cada ocasião de amostragem foram coletados aleatoriamente oito brotos. Através da análise, pelos índices de dispersão I e Iδ, o padrão de distribuição espacial das larvas de P. citrella entre as plantas e nos brotos de ‘Montenegrina’ e ‘Murcott’ foi agregado na maioria das ocasiões de amostragem. O padrão de distribuição espacial das larvas do minador-dos-citros nas folhas mostrou-se diferente do registrado em copas das plantas e brotos, os índices I, Iδ e o parâmetro k indicaram distribuição aleatória.; The spatial distribution of larvae of Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae), the citrus leaf miner, in leaves, shoots, and tree crowns of Montenegrina tangerine (Citrus deliciosa Tenore) and Murcott tangor (Citrus sinensis L. Osbeck x Citrus reticulata Blanco) was determined. Fortnightly samplings from July/2001 to June/2003...

Geostatistical analysis of the spatial distribution of Rotylenchulus reniformis on cotton cultivated under crop rotation

Farias, PRS; Barbosa, J. C.; Vieira, SR; Sanchez-Vila, X; Ferraz, LCCB
Fonte: Mylnefield Research Services Publicador: Mylnefield Research Services
Tipo: Artigo de Revista Científica Formato: 1-9
Português
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The spatial distribution of Rotylenchulus reniformis on cotton cultivated in crop rotation with sorghum-peanut-velvetbean was studied using geostatistics. The experimental field, which had been continuously cropped with cotton for 20 years, comprised two 32 x 48 m-grids, each divided in sixty-four 4 x 6 in sampling plots. For all crops, 300 cm(3) soil samples were taken at the center of each plot at crop germination (Pi) and again at harvest (Pf), from which the numbers of nematodes were determined. The results revealed that the spatial distribution of R. reniformis was highly aggregated and with the aid of geostatistical techniques the nematode intensities were mapped and the risk areas accurately identified. Consequently, geostatistics is here considered a useful tool for planning nematode control strategies, particularly in precision agriculture.

Density and spatial distribution of Atta sexdens rubropilosa and Atta laevigata colonies (Hym., Formicidae) in Eucalyptus spp. forests

Ramos, Vania M.; Forti, Luiz C.; Andrade, Ana Paula P.; Noronha, Newton C.; Camargo, Roberto da Silva
Fonte: California State University Publicador: California State University
Tipo: Artigo de Revista Científica Formato: 775-781
Português
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); The present study determined the density and spatial distribution of nests of the leaf-cutting ants Atta sexdens rubropilosa and A laevigata in an area of Eucalyptus spp. forest. The research was accomplished between 05/2000 and 11/2001, on a farm located in Botucatu, SP, inside Area 19, with approximately 56,000 m(2), without a history of control for at least 3 years. The operation was accomplished by theodolite. The collected data facilitated the making of a working area map, containing the exact location of all the nests. For each one of the nests, its identification, codification, measurements and location in relation to the closest border of the area were also obtained. The density of nests found in the study area was 10 nests/ha, considering the two species present. The data obtained also demonstrated the tendency of the nests to concentrate in strips located closer to the borders of the area. Regression analysis revealed the existence of a negative correlation between distance from the borders and the number of colonies. Analysis of spatial distribution of colonies in the area also showed that the distribution is aggregated...

The effect of depth and sediment type on the spatial distribution of shallow soft-bottom amphipods along the southern Portuguese coast

Carvalho, Susana; Cunha, Marina R.; Pereira, Fábio; Pousao-Ferreira, P.; Santos, M. N.; Gaspar, M. B.
Fonte: Springer Verlag Publicador: Springer Verlag
Tipo: Artigo de Revista Científica
Português
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The present study provides updated information on amphipod assemblages of the southern Portuguese coast, the most south-western part of continental Europe. The influence of depth and sediment type on the spatial distribution of shallow soft-bottom amphipods was tested by means of univariate and multivariate methods. Samples were collected down to 40 m depth within areas ranging from very fine sand to gravel. The ratio between density and diversity was found to increase with depth and from coarser to finer sediments. Both physical variables tested were found to play a major role in structuring amphipod assemblages. However, some dominance of depth was evident as samples were mainly separated according to this variable. Moreover, while only 15 taxa were common to all depth levels, 35 were collected from all sediment types. Both depth and sediment type may override the potential effects of geographical location, as samples from different areas along the southern Portuguese coast were biologically related. A peculiar habitat was sampled in this study: a maerl bed, which was confirmed to be a hotspot of density. Nevertheless, this habitat did not harbor a distinct amphipod assemblage but some taxa such as Caprella spp., Lembos websteri...

Spatial distribution of leprosy in areas of risk in Vitoria, State of Espirito Santo, Brazil, 2005 to 2009

Sampaio,Poliane Barbosa; Madeira,Elizabeth Santos; Diniz,Lucia; Noia,Ethel Leonor; Zandonade,Eliana
Fonte: Sociedade Brasileira de Medicina Tropical - SBMT Publicador: Sociedade Brasileira de Medicina Tropical - SBMT
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2013 Português
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Introduction Leprosy remains a relevant public health issue in Brazil. The objective of this study was to analyze the spatial distribution of new cases of leprosy and to detect areas with higher risks of disease in the City of Vitória. Methods The study was ecologically based on the spatial distribution of leprosy in the City of Vitória, State of Espírito Santo between 2005 and 2009. The data sources used came from the available records of the State Health Secretary of Espírito Santo. A global and local empirical Bayesian method was used in the spatial analysis to produce a leprosy risk estimation, and the fluctuation effect was smoothed from the detection coefficients. Results The study used thematic maps to illustrate that leprosy is distributed heterogeneously between the neighborhoods and that it is possible to identify areas with high risk of disease. The Pearson correlation coefficient of 0.926 (p = 0.001) for the Local Method indicated highly correlated coefficients. The Moran index was calculated to evaluate correlations between the incidences of adjoining districts. Conclusions We identified the spatial contexts in which there were the highest incidence rates of leprosy in Vitória during the studied period. The results contribute to the knowledge of the spatial distribution of leprosy in the City of Vitória...

Spatial distribution of the Human T-Lymphotropic Virus types I and II (HTLV-I/II) infection among blood donors of Hemominas Foundation, Belo Horizonte, Minas Gerais State, Brazil, 1994-1996

Monteiro-de-Castro,Mônica Silva; Assunção,Renato Martins; Proietti,Fernando Augusto
Fonte: Escola Nacional de Saúde Pública Sergio Arouca, Fundação Oswaldo Cruz Publicador: Escola Nacional de Saúde Pública Sergio Arouca, Fundação Oswaldo Cruz
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2001 Português
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We conducted a cross-sectional study of the spatial distribution of HTLV-I/II infection among blood donors of Hemominas Foundation, living in Belo Horizonte, from 1994 to 1996. Study population (1,022) was composed by 533 cases (positive Western Blot (WB), indeterminate WB and ELISA positive without WB result) and a random sample of 489 non-cases (HTLV-I/II serum negative). Cases and non-cases were georeferenced using the exact or an approximation of the household address reported at the blood donation interview. Using multivariate analysis, cases with WB result are less likely to be reposition blood donors compared to voluntary ones (OR = 0.70; CI 95%: 0.50-0.99). Using the difference between univariate K functions, we found no evidence that cases and non-cases differ in their spatial distribution. We found no evidence that cases with and without WB result differ in the distance between their residence and Hemominas Foundation. No donors without WB result were georeferenced by the exact address. These donors could not have received the Hemominas letter inviting them to return to collect the second blood sample.

Seed shadow, seedling recruitment, and spatial distribution of Buchenavia capitata (Combretaceae) in a fragment of the Brazilian Atlantic Forest

Santos,B. A.; Melo,F. P. L.; Tabarelli,M.
Fonte: Instituto Internacional de Ecologia Publicador: Instituto Internacional de Ecologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2006 Português
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Here we describe the seed shadow, seedling recruitment, ontogenetic structure and spatial distribution of Buchenavia capitata (an emergent canopy tree) in a 380-ha fragment of the Atlantic forest in northeast Brazil. In particular, we examine seed distribution around 10 parental trees and both seedling recruitment and mortality, during an 18 month period beneath and around parental trees. Moreover, we describe: (1) B. capitata occurrence within treefall gaps; (2) population structure in terms of ontogenetic stages for the whole site; and (3) spatial distribution of adults within an area of 51 hectares. 99% of seeds were found beneath parent crowns (n = 4,236) and seed density reached 14.6 ± 29.9 seeds/m² (0-140 seeds/m²). 49% of all seeds germinated but seedling mortality reached 100% after an 18 month period. In addition, saplings of B. capitata were not found in forest understory and within 30 treefall gaps (94-2,350 m²). The adults showed an average DBH of 69.3 ± 22.1 cm, were 19.2 ± 2.9 m tall and presented a clumped spatial distribution. B. capitata matched some of the features presented by shade intolerant trees or large-gap specialists, and we hypothesize that low rates or even lack of long distance seed dispersal events may be reducing the probability of B. capitata seeds reaching suitable habitats for successful seedling recruitment and growth. Because of that (1) seedlings face high levels of early mortality; (2) there is no sapling recruitment at the study site; and (3) local population faces senility and it is threatened by local extinction.

Effects of flooding on the spatial distribution of soil seed and spore banks of native grasslands of the Pantanal wetland

Oliveira,Patricia Carla de; Torezan,José Marcelo Domingues; Cunha,Catia Nunes da
Fonte: Sociedade Botânica do Brasil Publicador: Sociedade Botânica do Brasil
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2015 Português
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ABSTRACTTo better understand the role that flooding plays in shaping plant communities of native floodable grasslands of the Pantanal and to characterize the spatial distribution of plants, we present the results of a survey of soil seed and spore banks using the seedling emergence method. We hypothesized that terrain subjected to the deepest and longest flooding should have higher propagule abundance and richness. The species composition and distribution of seeds and spores in the soil were assessed at five sites using three sampling positions at each according to inundation intensity. In each sample position 2cm-thick soil samples were collected in quadrats to a depth of 10cm. Litter was also collected as an independent layer. Sample monitoring in the greenhouse resulted in the emergence of 5489 seedlings, or 6353 propagules.m-2. Both the litter layer and the deepest soil layer had low abundances. A total of forty-four morphospecies (16 families) were recorded. Both seedling abundance and species richness were concentrated in the more floodable center sections. Isoetes pedersenii, Eleocharis minima, Sagittaria guayanensis, Rotala mexicana, Eleocharis plicarhachis, and Panicum laxum were the most abundant species. The species composition and spatial distribution of the propagule bank suggests that flooding plays a crucial role in seasonal vegetation dynamics in Pantanal wetlands...

Distribuição espacial do risco de hipertensão arterial sistêmica e diabetes mellitus em área do município de Pedreira - SP; Spatial distribution of the risk of high blood pressure and diabetes mellitus in the area of Pedreira, SP, Brazil

Adriano Peres Lora
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 27/08/2010 Português
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Este estudo aborda associações existentes entre a distribuição espacial de risco de casos de Hipertensão Arterial Sistêmica (HAS) e Diabetes Mellitus (DM) em uma determinada área de atuação de duas equipes de Saúde da Família, no Município de Pedreira - SP. Para tanto, foram usados dados contidos em planilhas eletrônicas elaboradas pelas equipes com dados dos cadastros das famílias, acrescentadas coordenadas "x" e "y" de cada um dos domicílios do território em questão, assinaladas por aparelho de GPS. As informações foram trabalhadas empregando-se modelo aditivo generalizado multinomial utilizando a família politômica, dentro do pacote estatístico XGAM; sendo duas variáveis, HAS presente ou ausente e DM presente ou ausente. Utilizou-se um grupo de co-variáveis para ajuste no modelo semi-paramétrica, composto por: sexo, idade, escolaridade, posição na família e tabagismo. A utilização da metodologia na área permite concluir que a distribuição de HAS e DM estão relacionadas com o espaço. A variação espacial do risco ocorre tanto no modelo 1 (não paramétrica), quanto no modelo 2 (semi-paramétrica). O modelo 2, explica melhor a distribuição de risco do que o modelo 1. Apesar da variação na distribuição do risco ser menor no modelo 2...

SPATIAL DISTRIBUTION OF LYMNAEIDAE (MOLLUSCA, BASOMMATOPHORA), INTERMEDIATE HOST OF Fasciola hepatica LINNAEUS, 1758 (TREMATODA, DIGENEA) IN BRAZIL

Medeiros,Camilla; Scholte,Ronaldo Guilherme Carvalho; D'ávila,Sthefane; Caldeira,Roberta Lima; Carvalho,Omar dos Santos
Fonte: Instituto de Medicina Tropical Publicador: Instituto de Medicina Tropical
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2014 Português
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Snails of the family Lymnaeidae act as intermediate hosts in the biological cycle of Fasciola hepatica, which is a biological agent of fasciolosis, a parasitic disease of medical importance for humans and animals. The present work aimed to update and map the spatial distribution of the intermediate host snails of F. hepatica in Brazil. Data on the distribution of lymnaeids species were compiled from the Collection of Medical Malacology (Fiocruz-CMM, CPqRR), Collection of Malacology (MZUSP), “SpeciesLink” (CRIA) network and through systematic surveys in the literature. Our maps of the distribution of lymnaeids show that Pseudosuccinea columella is the most common species and it is widespread in the South and Southeast with few records in the Midwest, North and Northeast regions. The distribution of the Galba viatrix, G. cubensis and G. truncatula showed a few records in the South and Southeast regions, they were not reported for the Midwest, North and Northeast. In addition, in the South region there are a few records for G. viatrix and one occurrence of Lymnaea rupestris. Our findings resulted in the first map of the spatial distribution of Lymnaeidae species in Brazil which might be useful to better understand the fasciolosis distribution and delineate priority areas for control interventions.

Spatial distribution of Plecoptera nymphs in streams of a mountainous area of Central Brazil

BISPO,P. C.; FROEHLICH,C. G.; OLIVEIRA,L. G.
Fonte: Instituto Internacional de Ecologia Publicador: Instituto Internacional de Ecologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2002 Português
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In this paper the spatial distribution of Plecoptera nymphs in the Almas' River basin, Pirenópolis, GO, was studied. Two Surber samples, each comprising 20 sampling units and totalling 2 m², were taken in each of the 13 stations, one during the rainy season (January 1994) and the second during the dry season (July 1994). In 5 of these stations, monthly samplings were made from June 1993 to July 1994; in these, temperature, velocity, discharge, electrical conductivity and pH were measured. Regional rainfall was also obtained. To ascertain the distribution of nymphs in the habitat, a separate sample was taken. Of the factors considered, the most important affecting the spatial distribution of the stonefly nymphs were altitude, stream order, and anthropic influence. Locally, the genera Anacroneuria and Kempnyia showed clumped distributions, but the data for Gripopteryx and Tupiperla were inconclusive due to low numbers.

Spatial distribution of Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae) larvae in three scales

Jesus,CR.; Redaelli,LR.
Fonte: Instituto Internacional de Ecologia Publicador: Instituto Internacional de Ecologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2008 Português
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The spatial distribution of larvae of Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae), the citrus leaf miner, in leaves, shoots, and tree crowns of Montenegrina tangerine (Citrus deliciosa Tenore) and Murcott tangor (Citrus sinensis L. Osbeck x Citrus reticulata Blanco) was determined. Fortnightly samplings from July/2001 to June/2003, in orchards located in Montenegro (29º 68’ S and 51º 46’ W), RS, Brazil, were carried out. At each sampling occasion eighth shoots randomly selected were collected. The spatial distribution pattern of P. citrella larvae between tree crowns and in the shoots was aggregated in most sampling occasions in both citrus species. Nevertheless, on the leaves, this pattern followed a random distribution, as indicated by the indices I, Idelta and k parameter.

Towards a hierarchical framework for modelling the spatial distribution of animals

Mackey, Brendan; Lindenmayer, David
Fonte: Blackwell Publishing Ltd Publicador: Blackwell Publishing Ltd
Tipo: Artigo de Revista Científica
Português
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Aim: A hierarchical framework is presented for modelling the spatial distribution of terrestrial vertebrate animals. Location: The location of the study is the montane ash forests of the Central Highlands of Victoria, south-eastern Australia. Methods: The

Spatial distribution of annual grass weed populations in winter cereals

González-Andújar, José Luis; Saavedra, Milagros
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo Formato: 77021 bytes; application/pdf
Português
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5 pages; The spatial distribution of 12 annual weed species in 52 winter cereal fields was studied by applying frequency distribution and dispersion indices. Avena sterilis and Lolium rigidum were clearly the dominant species, infesting the 38% of the fields. The dispersion indices, viz. variance to media ratio, David and Moore’s index, and k of the negative binomial revealed that the studied weed species followed an aggregated or contagious distribution pattern. In 54 of the 68 cases (specie-site) and in 10 of the 12 fields with multiple infestation studied, the weed populations were well represented by fitting the negative binomial distribution to frequency distribution of weed counts. Estimated values of parameter k showed a great variability amongst fields and were, in most cases, small indicating a high degree of patchiness. There was no stable or common kc value across field sites for all the weed species populations. This makes management decisions on weed control less easy in these fields.; Ministerio de Educacion y Ciencia project (AGL 2002-3801) and FEDER; Peer reviewed

Determinants of spatial distribution in a bee community : nesting resources, flower resources, and body size

Torné-Noguera, Anna; Rodrigo Domínguez, Anselm; Arnan Viadiu, Xavier; Osorio, Sergio; Barril-Graells, Helena; Rocha-Filho, Léo Correia da; Bosch Gras, Jordi
Fonte: Universidade Autônoma de Barcelona Publicador: Universidade Autônoma de Barcelona
Tipo: Artigo de Revista Científica Formato: application/pdf
Publicado em //2014 Português
Relevância na Pesquisa
67.161006%
Understanding biodiversity distribution is a primary goal of community ecology. At a landscape scale, bee communities are affected by habitat composition, anthropogenic land use, and fragmentation. However, little information is available on local-scale spatial distribution of bee communities within habitats that are uniform at the landscape scale. We studied a bee community along with floral and nesting resources over a 32 km2 area of uninterrupted Mediterranean scrubland. Our objectives were (i) to analyze floral and nesting resource composition at the habitat scale. We ask whether these resources follow a geographical pattern across the scrubland at bee-foraging relevant distances; (ii) to analyze the distribution of bee composition across the scrubland. Bees being highly mobile organisms, we ask whether bee composition shows a homogeneous distribution or else varies spatially. If so, we ask whether this variation is irregular or follows a geographical pattern and whether bees respond primarily to flower or to nesting resources; and (iii) to establish whether body size influences the response to local resource availability and ultimately spatial distribution. We obtained 6580 specimens belonging to 98 species. Despite bee mobility and the absence of environmental barriers...

Seasonal Spatial Distribution Patterns Of A Capybara (Hydrochoerus Hydrochaeris) Population In The Flooded Savannas Of Colombia

Maldonado-Chaparro,Adriana; Sánchez Palomino,Pedro
Fonte: Mastozoología neotropical Publicador: Mastozoología neotropical
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2010 Português
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Little is known about spatial induced processes regulating population dynamics in capybara (Hydrochoerus hydrochaeris), a social rodent from the lowlands of South America, an aspect that may explain the causative mechanism involved in a spatial density-dependent process like mortality and dispersal. We investigated and compared the spatial pattern of herds in a capybara population in the eastern savannas of Colombia. Herd locations were mapped during two contrasting periods of the year and changes in herd spatial distribution were measured using scale-dependent point pattern analyses, pair correlation function g(r) and the normalize K-function, (L(r)). Our results show that 1) herd size increases during the dry season; 2) herd spatial distribution followed a scale-dependent pattern; 3) regularity at small scales provides evidence of intra-specific competition between herds; and 4) clumped distribution was probably caused mainly by behavioral responses and habitat heterogeneity. This study highlights the importance of spatial statistics in the study of seasonal spatial distribution patterns of capybara herds, and their behavioral and ecological causes. It sheds light on ecological aspects such as space use and habitat influence.

Geostatistical modeling of clay spatial distribution in siliciclastic rock samples using the plurigaussian simulation method

Méndez-Venegas,Javier; Díaz-Viera,Martín A.
Fonte: Instituto de Geofísica, UNAM Publicador: Instituto de Geofísica, UNAM
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2013 Português
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In order to implement secondary and enhanced oil recovery processes in complex terrigenous formations as is usual in turbidite deposits, a precise knowledge of the spatial distribution of shale grains is a crucial element for the fluid flow prediction. The reason of this is that the interaction of water with shale grains can significantly modify their size and/or shape, which in turn would cause porous space sealing with the subsequent impact in the flow. In this work, a methodology for stochastic simulations of spatial grains distributions obtained from scanning electron microscopy images of siliciclastic rock samples is proposed. The aim of the methodology is to obtain stochastic models would let us investigate the shale grain behavior under various physico-chemical interactions and flux regimes, which in turn, will help us get effective petrophysical properties (porosity and permeability) at core scale. For stochastic spatial grains simulations a plurigaussian method is applied, which is based on the truncation of several standard Gaussian random functions. This approach is very flexible, since it allows to simultaneously manage the proportions of each grain category in a very general manner and to rigorously handle their spatial dependency relationships in the case of two or more grain categories. The obtained results show that the stochastically simulated porous media using the plurigaussian method adequately reproduces the proportions...

Spatial distribution of the Human T-Lymphotropic Virus types I and II (HTLV-I/II) infection among blood donors of Hemominas Foundation, Belo Horizonte, Minas Gerais State, Brazil, 1994-1996

Monteiro-de-Castro,Mônica Silva; Assunção,Renato Martins; Proietti,Fernando Augusto
Fonte: Escola Nacional de Saúde Pública Sergio Arouca, Fundação Oswaldo Cruz Publicador: Escola Nacional de Saúde Pública Sergio Arouca, Fundação Oswaldo Cruz
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2001 Português
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We conducted a cross-sectional study of the spatial distribution of HTLV-I/II infection among blood donors of Hemominas Foundation, living in Belo Horizonte, from 1994 to 1996. Study population (1,022) was composed by 533 cases (positive Western Blot (WB), indeterminate WB and ELISA positive without WB result) and a random sample of 489 non-cases (HTLV-I/II serum negative). Cases and non-cases were georeferenced using the exact or an approximation of the household address reported at the blood donation interview. Using multivariate analysis, cases with WB result are less likely to be reposition blood donors compared to voluntary ones (OR = 0.70; CI 95%: 0.50-0.99). Using the difference between univariate K functions, we found no evidence that cases and non-cases differ in their spatial distribution. We found no evidence that cases with and without WB result differ in the distance between their residence and Hemominas Foundation. No donors without WB result were georeferenced by the exact address. These donors could not have received the Hemominas letter inviting them to return to collect the second blood sample.