نتایج جستجو برای: nitrogen species

تعداد نتایج: 653271  

Journal: :Ecological applications : a publication of the Ecological Society of America 2011
Robert J Steers Jennifer L Funk Edith B Allen

Productivity in desert ecosystems is primarily limited by water followed by nitrogen availability. In the deserts of southern California, nitrogen additions have increased invasive annual plant abundance. Similar findings from other ecosystems have led to a general acceptance that invasive plants, especially annual grasses, are nitrophilous. Consequently, reductions of soil nitrogen via carbon ...

Journal: :Current medicinal chemistry 2004
Earl R Stadtman

Organisms are constantly exposed to many different forms of reactive oxygen species and reactive nitrogen species that damage proteins, nucleic acids, and lipids, leading to loss of biological function. The possibility that reactive oxygen/nitrogen-mediated protein damage contributes to the aging process is supported by results of many studies showing that aging is associated with the accumulat...

Journal: :Environmental pollution 2011
Christian Damgaard Lennarth Jensen Lise Marie Frohn Finn Borchsenius Knud Erik Nielsen Rasmus Ejrnæs Carly J Stevens

The effect of atmospheric nitrogen deposition on the species richness of acid grasslands was investigated by combining data from a large Danish monitoring program with a large European data set, where a significant non-linear negative effect of nitrogen deposition had been demonstrated (Stevens et al., 2010). The nitrogen deposition range in Denmark is relatively small and when only considering...

Journal: :Frontiers in bioscience : a journal and virtual library 2007
Guy C Brown

Nitric oxide (NO) and its derivatives (reactive nitrogen species) have multiple effects on mitochondria that impact on cell physiology and cell death. Mitochondria may produce and consume NO and NO stimulates mitochondrial biogenesis, apparently via cGMP upregulation of transcriptional factors. NO inhibits mitochondrial respiration via: (A) an acute and reversible inhibition of cytochrome oxida...

Journal: :Journal of Clinical Biochemistry and Nutrition 2009

2014
Chen Xiaobo Liu Yibin Wang Jin Shan Honghong Yang Chaohe Li Chunyi

In this study, the classes and structures of nitrogen species in coker gas oil (CGO) are characterized by electrospray ionization (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) combined with Fourier transform infrared (FT-IR) spectroscopy. The results demonstrate that the m/z of basic and non-basic nitrogen compounds ranges from 180 to 560 and from 200 to 460, res...

دیانتی تیلکی, قاسمعلی , شکرالهی, شکوفه , مرادی, حمید رضا ,

The aim of the present study was investigating some ecological factors in the habitats of four species and determining the most significant variables affecting the presence and distribution of these species. Study area, which was about 4600 ha, was located at Polur, Mazandaran province. For this purpose, after primary survey and selection of main plant species, 3 transects 150 meter in length w...

Journal: :Journal of evolutionary biology 2012
L Pellissier S Rasmann G Litsios K Fiedler A Dubuis J Pottier A Guisan

The amount of nitrogen required to complete an insect's life cycle may vary greatly among species that have evolved distinct life history traits. Myrmecophilous caterpillars in the Lycaenidae family produce nitrogen-rich exudates from their dorsal glands to attract ants for protection, and this phenomenon has been postulated to shape the caterpillar's host-plant choice. Accordingly, it was post...

2015
Jianhua Zhang He Li Haihua Shen Yahan Chen Jingyun Fang Zhiyao Tang Jian Liu

Nutrient resorption from senescing leaves is a key mechanism of nutrient conservation for plants. The nutrient resorption efficiency is highly dependent on leaf nutrient status, species identity and soil nutrient availability. Nitrogen is a limiting nutrient in most ecosystems, it is widely reported that nitrogen resorption efficiency (NRE) was highly dependent on the soil nitrogen availability...

2013
Balaraman Kalyanaraman

This article provides a succinct but limited overview of the protective and deleterious effects of reactive oxygen and nitrogen species in a clinical context. Reactive oxygen species include superoxide, hydrogen peroxide, single oxygen and lipid peroxides. Reactive nitrogen species include species derived from nitric oxide. This review gives a brief overview of the reaction chemistry of these s...

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