نتایج جستجو برای: mean of diversity shannon

تعداد نتایج: 21194359  

Journal: :Clinical and molecular allergy : CMA 2008
Erick Forno Andrew B Onderdonk John McCracken Augusto A Litonjua Daniel Laskey Mary L Delaney Andrea M DuBois Diane R Gold Louise M Ryan Scott T Weiss Juan C Celedón

BACKGROUND A modest number of prospective studies of the composition of the intestinal microbiota and eczema in early life have yielded conflicting results. OBJECTIVE To examine the relationship between the bacterial diversity of the gut and the development of eczema in early life by methods other than stool culture. METHODS Fecal samples were collected from 21 infants at 1 and 4 months of ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیراز - دانشکده زبانهای خارجی 1389

the aim of the present study was to investigate the frequency and the type of discourse markers used in the argumentative and expository writings of iranian efl learners and the differences between these text features in the two essay genres. the study also aimed at examining the influence of the use of discourse markers on the participants’ writing quality. to this end the discourse markers us...

سالاروند, مرضیه, عرفانزاده, رضا, کوچ, یحیی,

This study aimed to compare plant species diversity indices (diversity and richness) and some physico-chemical properties of soil among forest, ecotone and rangeland habitats. Vegetation sampling was done randomly at each habitat. One dominant community was selected in each habitat and one key area was distinguished in each community and 8×1m2 plots were randomly established in each key area. I...

خلیل‌آبادی, سمیه, سفیانیان, علیرضا, متین‌خواه, سیدحمید, همامی, محمودرضا, کابلی, محمد,

  Determining landscape parameters influencing species richness of habitat patches is one of the most important issues in conservation biology. Many previous studies have investigated the influence of habitat parameters on bird assemblages in forest patches, but studies seeking effects of oasis parameters on bird assemblages are very scarce. Karkas Protected Area is located in semi-arid zone in...

2015
J. S. Glasenapp B. R. Frieden C. D. Cruz

Shannon information has, in the past, been applied to quantify the genetic diversity of many natural populations. Here, we apply the Shannon concept to consecutive generations of alleles as they evolve over time. We suppose a genetic system analogous to the discrete noisy channel of Shannon, where the signal emitted by the input (mother population) is a number of alleles that will form the next...

Journal: :Journal of clinical microbiology 2005
Gavin P Gafan Victoria S Lucas Graham J Roberts Aviva Petrie Michael Wilson David A Spratt

Studies using molecular techniques have demonstrated that a culture-based approach can severely underestimate the bacterial diversity in most environments. One of the molecular techniques that has been applied in microbial ecology is denaturing gradient gel electrophoresis (DGGE). The purpose of this study was to investigate differences in the microbiota of plaque, using a number of analysis te...

A.R. Mirzajani, B. Kiabi S.A. Nezami

In the present study, some ecological factors were studied for Amphipoda at different depths. The Shannon, Margalef, and Hill indices were used to determine the  species diversity, richness and evenness, respectively. In addition, the association and niche overlap values were estimated. Indices of species richness and diversity were highest at 50 and 100m depths, respectively.  The ordination o...

Journal: :علوم گیاهان زراعی ایران 0
شکیبا شاهمرادی دانشجوی دکتری، پردیس کشاورزی و منابع طبیعی دانشگاه تهران محمدرضا چایی چی دانشیار پردیس کشاورزی و منابع طبیعی دانشگاه تهران جواد مظفری دانشیار، موسسه تحقیقات اصلاح و تهیه نهال و بذر. داریوش مظاهری استاد ، پردیس کشاورزی و منابع طبیعی دانشگاه تهران فرزاد شریف زاده دانشیار پردیس کشاورزی و منابع طبیعی دانشگاه تهران

knowledge about genetic diversity is an essential step towards conservation of genetic resources and developing further strategies for plant improvement. the objective of this research was to evaluate the agronomical and morphological traits and determine the level of variation within wild barley ecotypes especially for acclimation traits. in this study 188 ecotypes of wild barley (hordeumspont...

Journal: :Molecular biotechnology 2015
Masood Ghasemi Ghehsareh Hassan Salehi Morteza Khosh-Khui Ali Niazi

There are many species of jasmines in different regions of Iran in natural or cultivated form, and there is no information about their genetic status. Therefore, inter-simple sequence repeat (ISSR) analysis was used to evaluate genetic variations of the 53 accessions representing eight species of Jasminum collected from different regions of Iran. A total of 21 ISSR primers were used which gener...

Journal: :Revista de biologia tropical 2008
Ernesto Velázquez-Velázquez M Eugenia Vega-Cendejas Jorge Navarro-Alberto

Composition and abundance of the ichthyofauna in estuarine and coastal lagoon systems of the South Pacific in Mexico have been scarcely studied. In particular, there is a lack of information on how environmental variables determine the spatio-temporal structure of fish assemblages in those habitats. In this study, fishes were sampled by drop net during twelve months (May 2004 - April 2005) in 2...

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