نتایج جستجو برای: diversity index

تعداد نتایج: 577656  

2011
A. Wilby

Contents 1. Introduction – biodiversity in agricultural ecosystems 2. Planned diversity and the functioning of agricultural systems 2.1. Intraspecific diversity 2.2. Species diversity 2.3. Habitat and landscape diversity 3. Unplanned diversity and the functioning of agricultural systems. 3.1. Pollination services 3.2. Soil processes 3.3. Natural pest control 4. Conclusions Bibliography Biograph...

2012
S. J. Salter J. Hinds K. A. Gould L. Lambertsen W. P. Hanage M. Antonio P. Turner P. W. M. Hermans H. J. Bootsma K. L. O'Brien S. D. Bentley

The capsule polysaccharide locus (cps) is the site of the capsule biosynthesis gene cluster in encapsulated Streptococcus pneumoniae. A set of pneumococcal samples and non-pneumococcal streptococci from Denmark, the Gambia, the Netherlands, Thailand, the UK and the USA were sequenced at the cps locus to elucidate serologically mistyped or non-typable isolates. We identified a novel serotype 33B...

2012
Maria Rebolleda-Gomez William Ratcliff Michael Travisano

The evolution of multicellularity was one of the key innovations in the history of life on Earth. Virtually all morphological and ecological diversity in macro-organisms builds upon the evolutionary potential associated with multicellularity. We examined the potential for ecological diversity to rapidly arise following transitions to multicellularity. Replicate microcosms containing the yeast S...

ژورنال: علوم آب و خاک 2006
عباس اسماعیلی, , محمدرضا احمدی, , احمد قانع, , علیرضا میرزاجانی, ,

Present study investigates macrobenthic invertebrates and their community structure in Chafrood river to classify and assess the study sites regarding the environmental anthropogenic factors. Along a 9 km distance, 8 study sites were selected, and macrobenthic were monthly sampled using a surber sampler (1600cm2, 250 μ mesh net) with 3 replicate at each station. Collected samples organisms were...

2003
Demetrio Boltovskoy Nancy Correa Andrés Boltovskoy

Approximately 7000 marine zooplanktonic species have been described so far for the World Ocean; in the South Atlantic the presence of 40% of these has been confirmed, and an additional 20–30% are expected to be recorded in the future. The overall number of described species is very low when compared with other communities, and yet it may not be too far from the final, complete inventory. Very a...

Journal: :Proceedings. Biological sciences 2011
Ben Adams Alice Carolyn McHardy

Punctuated antigenic change is believed to be a key element in the evolution of influenza A; clusters of antigenically similar strains predominate worldwide for several years until an antigenically distant mutant emerges and instigates a selective sweep. It is thought that a region of East-Southeast Asia with year-round transmission acts as a source of antigenic diversity for influenza A and se...

Journal: :Ecology 2008
Sébastien Villéger Norman W H Mason David Mouillot

Functional diversity is increasingly identified as an important driver of ecosystem functioning. Various indices have been proposed to measure the functional diversity of a community, but there is still no consensus on which are most suitable. Indeed, none of the existing indices meets all the criteria required for general use. The main criteria are that they must be designed to deal with sever...

Journal: Current Medical Mycology 2017

Background and Purpose: Candida parapsilosis is a predominant species found in nosocomial infection, particularly in hospitalized patients. The molecular epidemiology of the clinical strains of this species has not been well studied. The present study was performed with the aim of investigating the microsatellite genotyping of Candida parapsilosis among the Iranian clinical isolates. Materials...

ژورنال: زیست شناسی دریا 2020
Ganjian Khenari, Ali , Oskoein, Roghayeh , Zakerimehr, Mohammad Reza ,

Phytoplankton plays an important role in the material cycle and energy flow of the ecosystem, Therefore in this study, the distribution, frequency, and biodiversity of phytoplankton in Elimalat Lake were investigated. Sampling was performed in Elimalat Lake sessonally, located in Nur City, Mazandaran province, in 2019. In this study, 70 species of phytoplankton were classified into 5 phylum ...

Journal: :Anais da Academia Brasileira de Ciencias 2015
Jonas E Gallão Maria Elina Bichuette

Subterranean environments, even though they do not possess a primary production (photosynthesis), may present high biodiversity, faunistic originality, endemism, phylogenetic isolations and unique ecological and/or evolution events, in addition to rare taxa. Studies investigating the biological diversity in Neotropical caves are relatively rare and recent, and most of them have been conducted i...

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