نتایج جستجو برای: nitrogen species

تعداد نتایج: 653271  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیراز 1381

‏‎the community dynamics of aquatic coleoptera(insecta)in one of the spring-stream habitats of bammo national park in fars province called cheshmeh-ye-ghanbari is studied as a pilot project and model for acquaintance with and furthering the biodiversity studies on fauna of iran. sixteen species-populations out of nineteen of this community were already identified for their taxonomy and for thei...

Journal: :Science 2004
Carly J Stevens Nancy B Dise J Owen Mountford David J Gowing

A transect of 68 acid grasslands across Great Britain, covering the lower range of ambient annual nitrogen deposition in the industrialized world (5 to 35 kg Nha-1 year-1), indicates that long-term, chronic nitrogen deposition has significantly reduced plant species richness. Species richness declines as a linear function of the rate of inorganic nitrogen deposition, with a reduction of one spe...

Journal: :Applied and environmental microbiology 2012
Kimberley A Lema Bette L Willis David G Bourne

The complex symbiotic relationship between corals and their dinoflagellate partner Symbiodinium is believed to be sustained through close associations with mutualistic bacterial communities, though little is known about coral associations with bacterial groups able to fix nitrogen (diazotrophs). In this study, we investigated the diversity of diazotrophic bacterial communities associated with t...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2007
Benjamin Z Houlton Daniel M Sigman Edward A G Schuur Lars O Hedin

The response of tropical forests to climate change will depend on individual plant species' nutritional strategies, which have not been defined in the case of the nitrogen nutrition that is critical to sustaining plant growth and photosynthesis. We used isotope natural abundances to show that a group of tropical plant species with diverse growth strategies (trees and ferns, canopy, and subcanop...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس 1388

هدف از این مطالعه بررسی ارتباط رادیکالهای آزاد موجود در مایع منی با آسیب dna، پتانسیل غیر طبیعی غشاء میتوکندری، اپوپتوز و میزان لقاح در بیماران نابارور با علت مردانه می باشد. برای رسیدن به این هدف از نمونه اسپرم 120 زوج مراجعه کننده به پژوهشکده رویان جهت درمان ناباروری به علت فاکتور مردانه استفاده شد و از نظر پارامترهای اسپرمی مورد مطالعه قرار گرفت. نمونه مایع منی به میزان 1 میلی لیتر پس از آنا...

Journal: :desert 0
m. saberi faculty of natural resources, university of zabol, zabol, iran m. jafari professor, faculty of natural resources, university of tehran, karaj, iran a. tavili associate professor, faculty of natural resources, university of tehran, karaj, iran m.a. zare chahouki associate professor, faculty of natural resources, university of tehran, karaj, iran m. tahmoures msc. graduate, faculty of natural resources, university of tehran, karaj, iran

the aim of this research was to compare the amounts of existing mineral elements in plant aerial parts, litter and soil ofthree range species (bromus tomentellus, psathyrostachys fragilis, agropyron tauri) in order to investigate the litter effectof species on soil properties of taleghan rangeland. the measured mineral elements include carbon, nitrogen,phosphorous and potassium. after selection...

ژورنال: علوم آب و خاک 2008
امینی دهقی, مجید , فتاحی نیسیانی, فرهاد, مدرس ثانوی, سید علی محمد ,

In order to study the effect of planting dates and genistein on nitrogen content and nodulation of three annual Medicago species (Medicago polymorpha cv. Santiago M. rigidula cv. Ragidula, and M. radiata cv. Radiata), an experimental study was conducted during 2004-2005 on the Research Farm of Faculty of Agriculture, Tarbiat Modares University, Tehran (35°43′N and 51°8′E). The factors were arra...

2014
Gilles Havik Alessandro Catenazzi Milena Holmgren

Marine-derived nutrients can increase primary productivity and change species composition of terrestrial plant communities in coastal and riverine ecosystems. We hypothesized that sea nutrient subsidies have a positive effect on nitrogen assimilation and seedling survival of non-nitrogen fixing species, increasing the relative abundance of non-nitrogen fixing species close to seashore. Moreover...

Journal: :Chemical communications 2013
Satoshi Yasuda Li Yu Jeheon Kim Kei Murakoshi

Nitrogen-doped graphene materials with abundant pyridinic and quaternary nitrogen species were selectively synthesized by thermal surface polymerization of nitrogen-containing aromatic molecules. Catalytic studies revealed that the oxygen reduction by nitrogen-doped graphene, containing pyridinic and quaternary nitrogen species, proceeds via a four- and two-electron reduction pathway, respectiv...

Journal: :desert 2012
m. saberi m. jafari a. tavili m.a. zare chahouki m. tahmoures

the aim of this research was to compare the amounts of existing mineral elements in plant aerial parts, litter and soil ofthree range species (bromus tomentellus, psathyrostachys fragilis, agropyron tauri) in order to investigate the litter effectof species on soil properties of taleghan rangeland. the measured mineral elements include carbon, nitrogen,phosphorous and potassium. after selection...

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