نتایج جستجو برای: diversity indices
تعداد نتایج: 268614 فیلتر نتایج به سال:
Workgroup diversity can be conceptualized as variety, separation, or disparity. Thus, the proper operationalization of diversity depends on how a diversity dimension has been defined. Analytically, the minimal diversity must be obtained when there are no differences on an attribute among the members of a group, however maximal diversity has a different shape for each conceptualization of divers...
As for the entire Amazon Region, malaria continues to be a major health public problem in Roraima that presented an Annual Parasitic Index of 85.4 in 2005, the highest in Brazil. Information on anopheline breeding sites is an essential component in malaria control strategies. Aiming to contribute to the limited knowledge on anopheline immature forms in Roraima, collections and breeding site obs...
Diversity indices provide simple and powerful metrics for assessing biological communities. Based on entropy measures, the approach considers statistical and thermodynamic inferences to deduce ecological patterns. However, concerns exist regarding the accuracy of diversity indices. Because relative quantities depend on the sorting of organisms (e.g., guilds and species) and their interactions, ...
PURPOSE Several novel techniques have been developed recently to assess the breadth of a speaker's vocabulary exhibited in a language sample. The specific aim of this study was to increase our understanding of the validity of the scores generated by different lexical diversity (LD) estimation techniques. Four techniques were explored: D, Maas, measure of textual lexical diversity, and moving-av...
Temporal changes in the structure of biological communities are one of the factors affecting water quality assessment systems. The aim of our work was to analyze the temporal variability of benthic macroinvertebrates and its consequences for the established streams typology. The data analyzed come from a biomonitoring of streams of the Czech Republic during 2002-2005. Changes of the structure o...
Data from 247 global software development teams were used to examine the impact of temporal dispersion and leadership roles on the relationship between nationality diversity and team performance. Nationality diversity was positively related to team performance when project leaders regularly coordinate and monitor team members’ activities, and acted as mentors and facilitator. However, when nati...
Recently revisited, the concept of niche ecology has lead to the formalisation of functional and trophic niches using stable isotope ratios. Isotopic diversity indices (IDI) derived from a set of measures assessing the dispersion/distribution of points in the δ-space were recently suggested and increasingly used in the literature. However, three main critics emerge from the use of these IDI: 1)...
We investigated the prevalence and diversity of Escherichia coli strains isolated from surface waters from multiple watersheds within the South Nation River basin in eastern Ontario, Canada. The basin is composed of mixed but primarily agricultural land uses. From March 2004 to November 2007, a total of 2,004 surface water samples were collected from 24 sampling sites. E. coli densities ranged ...
The extent of rangeland is one of the most important characteristics of organic carbon uptake and storage in soil and plants. The present study investigates the indices of plant diversity and organic carbon storage in mountain pastures under grazing and 10-year enclosure in Asadabad. The rangeland is approximately 100 hectares and its rangelands are in good condition and are in the 2S class in ...
The community of endophytic fungi associated with Acer ginnala, a common tree in northeastern China, was investigated. Four media, PDA, Czapek's, WA and Sabouraud's, were used to inoculate explants from seeds, annual twigs and perennial twigs (xylem and bark). Media strongly affected the isolated species number, but not colonization frequency (CF) or isolation frequency (IF). To investigate med...
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