978 resultados para Habitat preference index
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The Iowa Leading Indicators Index (ILII) is a tool for monitoring the future direction of the Iowa economy and State revenues. Its eight components include an agricultural futures price index, an Iowa stock market index, average weekly manufacturing hours in Iowa, initial unemployment claims in Iowa, an Iowa new orders index, diesel fuel consumption in Iowa, residential building permits in Iowa, and the national yield spread.
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The aim of this paper is twofold: firstly, to carry out a theoreticalreview of the most recent stated preference techniques used foreliciting consumers preferences and, secondly, to compare the empiricalresults of two dierent stated preference discrete choice approaches.They dier in the measurement scale for the dependent variable and,therefore, in the estimation method, despite both using a multinomiallogit. One of the approaches uses a complete ranking of full-profiles(contingent ranking), that is, individuals must rank a set ofalternatives from the most to the least preferred, and the other usesa first-choice rule in which individuals must select the most preferredoption from a choice set (choice experiment). From the results werealize how important the measurement scale for the dependent variablebecomes and, to what extent, procedure invariance is satisfied.
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Learning has been postulated to 'drive' evolution, but its influence on adaptive evolution in heterogeneous environments has not been formally examined. We used a spatially explicit individual-based model to study the effect of learning on the expansion and adaptation of a species to a novel habitat. Fitness was mediated by a behavioural trait (resource preference), which in turn was determined by both the genotype and learning. Our findings indicate that learning substantially increases the range of parameters under which the species expands and adapts to the novel habitat, particularly if the two habitats are separated by a sharp ecotone (rather than a gradient). However, for a broad range of parameters, learning reduces the degree of genetically-based local adaptation following the expansion and facilitates maintenance of genetic variation within local populations. Thus, in heterogeneous environments learning may facilitate evolutionary range expansions and maintenance of the potential of local populations to respond to subsequent environmental changes.
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Orthoptera assemblages associated with macrophytes of floodplain lakes of the Paraná River. The Orthoptera assemblage composition varies considerably, depending on habitat type. This study examines the spatiotemporal relationship between plant diversity, hydrometric level, environmental variables and the Orthoptera richness and abundance in floodplain lakes connected permanently or temporarily with the main channel of the Paraná River. The grasshoppers were collected fortnightly (April 2006May 2007). A total of 17 species were recorded and classified according to their frequency of occurrence in constant (7), accessory (4), or accidental (6) species. In the two lakes, the greater species richness and abundance was recorded in summer, thereby coinciding with the highest water level of the Paraná River. The most significant correlation between the orthopteran richness and abundance was with the water level. The aquatic plant richness was significantly different between the lakes, but the vegetation was dominated by Eichhornia crassipes (Mart.) Solms. (Liliales, Pontederiaceae). The lake, which was connected permanently, presented the highest values of diversity and abundance, proving to be a more diverse assemblage. The beta diversity was higher in the temporary connected lake than in the permanently connected one. The orthopterans assemblages were different between the lakes, Cornops aquaticum and Tucayaca gracilis were the species that contributed more to the level of dissimilarity. C. aquaticum was more representative in the lake temporarily connected, while T. gracilis in the permanent connected one. The water level of the Paraná River and the connectivity of the floodplain lakes play an important role to explain the abundance and richness of their orthopteran assemblages.
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The problem of obesity is alarming public health authorities around the world. Therefore, it is important to study its determinants. In this paper we explore the empirical relationship between household income and body mass index (BMI) in nine European Union countries. Our findings suggest that the association is negative for women, but we find no statistically significant relationship for men. However, we show that the different relationship for men and women appears to be driven by the negative relationship for women between BMI and individual income from work. We tentatively conclude that the negative relationship between household income and BMI for women may simply be capturing the wage penalty that obese women suffer in the labor market.
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What is the importance of open habitat in a predominantly closed forest to the dung beetle assemblage? The Atlantic Forest in Brazil is one of the most highly disturbed ecosystems and is mainly represented by fragmented areas. However, in places where human disturbances have ceased, certain areas are showing a natural regeneration pattern. The aim of the present study was to determine how the dung beetle assemblage responds to distinct habitat structures in a fragment of Atlantic Forest. For such, open and closed forest areas were sampled in a fragment of the Atlantic Forest in the northeastern region of Brazil. Pitfall traps baited with excrement and carrion were used to collect the beetles. A total of 7,267 individuals belonging to 35 species were captured. Canthon chalybaeus and C. mutabilis were restricted to open areas. Nearly 90% of the individuals of C. aff. simulans and Deltochilum aff. irroratum were identified in these areas. A higher percentage (> 50%) of Canthon staigi, Dichotomius aff. depressicolis and D. aff. sericeus occurred in closed areas. Abundance differed between areas, with higher values in closed areas. Richness was not influenced by the habitat structure. NMDS ordination exhibited the segregation of areas and ANOSIM confirmed that this variable explained the assemblage of dung beetle species. The findings of the present study validate that open areas are associated to more restrictive conditions, limiting a higher abundance of dung beetle. Although situated near preserved fragments, the studied open areas increase the heterogeneity of the general landscape.
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Em Cabo Verde, ainda existe uma percentagem significativa de pobreza, tendo o índice da pobreza humana (IPH) no país, sido calculado em 15,8%, em 2006, pelo Instituto Nacional de Estatística. Assinala-se igualmente uma fraca capacidade de produção de riquezas e de empregos capazes de garantir melhores condições de vida à maior parte de sua população, (FMI, 2010: 36). Os últimos dados referentes à pobreza no país do QUIBB 2007 (Questionário Unificado de Indicadores Básicos de Bem Estar Social), referem que a incidência da pobreza diminuiu de 36,7% na população residente em 2001, para 26,6% da população em 2007, ou seja, um total de 32.000 pessoas deixaram de integrar o nível considerado de pobreza neste intervalo. De acordo com os mesmos dados, o concelho da Praia possui uma incidência de pobreza de 11,6% e São Domingos de 37,8%, concelhos esses, onde pertencem as duas comunidades em estudo, (UNICEF, 2011:36). Apesar dos esforços envidados para a melhoria das condições de vida da população e dos ganhos resultantes da implementação de várias políticas sociais e programas de desenvolvimento, constata-se que alguns grupos e categorias sociais continuam a enfrentar um conjunto de situações de precariedade de natureza económica e social que condicionam a sua qualidade de vida. Neste contexto, assinala-se o surgimento de várias ONG´s, como é o caso do CITI-Habitat, que foi criado como forma de dar resposta ao contexto de ajuda ao desenvolvimento das comunidades locais, visando reduzir e prevenir situações de desigualdade e exclusão social ainda existentes, atingindo particularmente os mais vulneráveis. Pretende-se, assim, com este trabalho analisar o papel do Citi Habitat no desenvolvimento local e no empoderamento desses grupos vulneráveis, das duas comunidades em estudo. Para a realização e concretização deste trabalho, utilizou-se a metodologia qualitativa bem como a quantitativa e, para a análise dos inquéritos aplicados aos sujeitos de pesquisa, foi feito o tratamento dos dados no programa informático, SPSS.
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En aquest estat de la qüestió, s’hi presenten els resultats d’una anàlisi sobre l’evolució i les característiques principals de les revistes de geografia incloses al Journal of Citation Reports dins de la versió del Social Science Citation Index i, per tant, amb factor d’impacte. El període d’estudi escollit ha estat el que va de 1997 a 2005, és a dir, al llarg dels darrers nou anys amb dades disponibles. En total, hi han aparegut incloses trenta-nou revistes, una bona part de les quals ha romàs a la llista durant tot el temps estudiat. Hi ha hagut deu publicacions que han estat situades entre les cinc amb més factor d’impacte de cada any, i cap no ha estat la primera més de dos anys seguits. S’han trobat divuit temàtiques diferents en el conjunt de les revistes, en destaquen les de caire generalista i les de geografia econòmica i regional. Una gran majoria dels volums està publicada per editorials, Blackwell Publishing n’és la més destacada. L’origen de les revistes és clarament anglosaxó, només n’hi trobem dues d’escrites en una altra llengua. La segona part de l’article descriu totes les publicacions contemplades en els nou anys estudiats, amb una petita ressenya de cadascuna
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The two volume record of the debates that occured during the thirty-nine days it took to draft the third constitution of the State of Iowa.
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The effects of patch size and isolation on metapopulation dynamics have received wide empirical support and theoretical formalization. By contrast, the effects of patch quality seem largely underinvestigated, partly due to technical difficulties in properly assessing quality. Here we combine habitat-quality modeling with four years of demographic monitoring in a metapopulation of greater white-toothed shrews (Crocidura russula) to investigate the role of patch quality on metapopulation processes. Together, local patch quality and connectivity significantly enhanced local population sizes and occupancy rates (R2 = 14% and 19%, respectively). Accounting for the quality of patches connected to the focal one and acting as potential sources improved slightly the model explanatory power for local population sizes, pointing to significant source-sink dynamics. Local habitat quality, in interaction with connectivity, also increased colonization rate (R2 = 28%), suggesting the ability of immigrants to target high-quality patches. Overall, patterns were best explained when assuming a mean dispersal distance of 800 m, a realistic value for the species under study. Our results thus provide evidence that patch quality, in interaction with connectivity, may affect major demographic processes.
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n the last two decades, interest in species distribution models (SDMs) of plants and animals has grown dramatically. Recent advances in SDMs allow us to potentially forecast anthropogenic effects on patterns of biodiversity at different spatial scales. However, some limitations still preclude the use of SDMs in many theoretical and practical applications. Here, we provide an overview of recent advances in this field, discuss the ecological principles and assumptions underpinning SDMs, and highlight critical limitations and decisions inherent in the construction and evaluation of SDMs. Particular emphasis is given to the use of SDMs for the assessment of climate change impacts and conservation management issues. We suggest new avenues for incorporating species migration, population dynamics, biotic interactions and community ecology into SDMs at multiple spatial scales. Addressing all these issues requires a better integration of SDMs with ecological theory.
Resumo:
The Iowa Leading Indicators Index (ILII) is a tool for monitoring the future direction of the Iowa economy and State revenues. Its eight components include an agricultural futures price index, an Iowa stock market index, average weekly manufacturing hours in Iowa, initial unemployment claims in Iowa, an Iowa new orders index, diesel fuel consumption in Iowa, residential building permits in Iowa, and the national yield spread.
Resumo:
The Iowa Leading Indicators Index (ILII) is a tool for monitoring the future direction of the Iowa economy and State revenues. Its eight components include an agricultural futures price index, an Iowa stock market index, average weekly manufacturing hours in Iowa, initial unemployment claims in Iowa, an Iowa new orders index, diesel fuel consumption in Iowa, residential building permits in Iowa, and the national yield spread.
Resumo:
The Iowa Leading Indicators Index (ILII) is a tool for monitoring the future direction of the Iowa economy and State revenues. Its eight components include an agricultural futures price index, an Iowa stock market index, average weekly manufacturing hours in Iowa, initial unemployment claims in Iowa, an Iowa new orders index, diesel fuel consumption in Iowa, residential building permits in Iowa, and the national yield spread.