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| Macneil, M. Aaron; Graham, Nicholas A. J.; Polunin, Nicholas V. C.; Kulbicki, Michel; Galzin, Rene; Harmelin-vivien, Mireille; Rushton, Steven P.. |
| Coral reefs are highly complex ecological systems, where multiple processes interact across scales in space and time to create assemblages of exceptionally high biodiversity. Despite the increasing frequency of hierarchically structured sampling programs used in coral-reef science, little progress has been made in quantifying the relative importance of processes operating across multiple scales. The vast majority of reef studies are conducted, or at least analyzed, at a single spatial scale, ignoring the implicitly hierarchical structure of the overall system in favor of small-scale experiments or large-scale observations. Here we demonstrate how alpha (mean local number of species), beta diversity (degree of species dissimilarity among local sites), and... |
| Tipo: Text |
Palavras-chave: Alpha; Beta; And gamma diversity biodiversity coral reefs ecological scales habitat structure mixed-effects models multiple working hypotheses; Reef-fish biomass species abundance species richness. |
| Ano: 2009 |
URL: https://archimer.ifremer.fr/doc/00207/31782/30195.pdf |
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| Perez, Jose Garcia; Cruz, Salvador; Rosado, Yolanda. |
| Resumen: El objetivo de este artículo es el estudio y generalización del método de las dos funciones de distribución, utilizado en la teoría de valoración y, más concretamente, en las valoraciones agrarias. El fundamento básico de este método, propuesto por Ballestero (1973), está en la utilización de un índice representativo del activo que pretendemos valorar y en la aceptación de una serie de hipótesis sobre la distribución de la variable índice y de la variable valor del activo. Hasta este momento y en todos los trabajos publicados sobre este método, se ha mantenido la limitación de utilizar un solo índice (aunque éste sea una síntesis de varios a los que pretende representar). En este trabajo se presenta un método que generaliza el anterior y que... |
| Tipo: Journal Article |
Palavras-chave: Valuation; Multi-index; Weighting; Beta; Agribusiness; Q10. |
| Ano: 2002 |
URL: http://purl.umn.edu/28759 |
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| Ramaswami, Bharat; Roe, Terry L.. |
| Earlier analyses of area yield crop insurance schemes used a reduced form linear relationship between individual and area yield. However, without knowledge of the structural framework, the analysis and design of alternative schemes is problematic. This paper resolves this problem. The paper characterizes the entire class of structural models equivalent to the reduced form. As a result, the beta, the slope coefficient of the reduced form is expressed as a function of structural parameters. Second, the structural model is used to analyze the relation between the aggregation (that determines area yields) and the risk reduction due to area yield insurance. Third, we consider optimal area yield insurance for an important class of structural models not... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Area Yield; Beta; Crop Insurance; Systemic Risks; Risk and Uncertainty; G22; Q14. |
| Ano: 2001 |
URL: http://purl.umn.edu/20638 |
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| Santana,Jordana Almeida; Ferreira,Ana Carolina de Andrade; Souza,Marina de Castro Campos de; Moreira,Maria Aparecida Scatamburlo; Lima,Magna Coroa; Cruz,Diogo Soares Gonçalves; Lobato,Francisco Carlos Faria; Silva,Rodrigo Otávio Silveira. |
| ABSTRACT: Despite the known importance of Clostridium perfringens as an enteropathogen in small ruminants, little is known about the role of its additional virulence factors or the frequency of the various C. perfringens genotypes in healthy goats; this complicates the laboratory diagnosis of the infections caused by this microorganism. In light of this, the aim of the present study was to isolate and genotype C. perfringens from stool samples from healthy goats in Brazil. Stool samples from 250 apparently healthy adult goats from 17 different herds in Minas Gerais, Brazil were collected, and isolation and genotyping of C. perfringens was performed. C. perfringens type A was isolated from 189 (75.6%) goats, whereas C. perfringens types C and D were each... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Clostridium perfringens type D; Microbiota; Epsilon; Beta. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782018000700452 |
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