نتایج جستجو برای: species changes and species
تعداد نتایج: 16982894 فیلتر نتایج به سال:
Phytoplankton is one of the most important biological groups in the aquatic environment, and its study and monitoring at different years reveals environmental changes as well as understanding of water quality. The aims of the present study are to study the structural pattern of phytoplankton with emphasis on new distinctive species (especially harmful and toxic), native and favorite species and...
changes in the fatty acid composition and biochemical indices of mackerel (which has a substantial lipid content) and shark (which has negligible lipid content) fillets stored at - 18°c for up to six months were measured. lipid content was measured (6.35% and 1.38%) in mackerel and shark, respectively; however it decreased during frozen storage in both fish species. in analysis of fatty acids t...
This study was undertaken to identify morphological changes in young seedlings of 5 Iranian almond species (Prunus dulcis, P. eburnea, P. eleagnifolia, P. haussknechti, and P. scoparia) under polyethylene glycol-induced drought stress. Drought stress caused a significant reduction in plant growth parameters such as fresh and dry weights of plant organs, leaf number, total leaf area, and leaf re...
Plant Diversity conservation is a main objective in rangelandmanagement. Plant diversity is a suitable index for showing the changes ofvegetation in rangelands and has a high correlation with ecosystem parameters.Therefore, using this index it is possible to find the changes and manage theecosystem correctly. The current research was performed to determine the speciesdiversity in Fashandak rang...
Reactive oxygen species (ROS)plays an important role in sperm motility. The physiological generation at low concentration induces beneficial effects on sperm functions and plays a significant role in sperm metabolism. Meanwhile, the excessive generation of reactive oxygen species can overwhelm protective mechanism and triggers changes in lipid and protein layers of sperm plasma membrane, which ...
arsenic is one of the heavy metals and nearly all its compounds, especially organic compounds, are toxic. the wide spectrum of diseases caused by this element has led to evaluation of the toxicity of different arsenic species and identification of the major natural and anthropogenic pollution sources of it in the nature. mining activities are among the main sources of anthropogenic pollution of...
Phytoplankton is one of the main components of wetlands, which plays a vital role in providing nutrients, oxygen for other organisms, stabilizing nitrogen and carbon dioxide. In the meantime, the current status of Lake Urmia highlights the need to conserve and protect wetlands related to these ecosystems and their living and non-living components. Therefore, this study was conducted to assist i...
objective: citrinin is a mycotoxin produced by several species of the genera aspergillus and penicillium and occurs mainly in food products and animal feed. some scientific reports show a link between citrinin and nephrotoxic and possibly a carcinogenic effect for humans. methods: samples collected by settling plates,in northern iran and pure culture isolation performed till the toxin measureme...
in this research, the effect of air pollution on proline concentration, soluble sugar, anatomical and morphological features was studied in two plant species malva parviflora and hordeum glaucum in 2009. the area of the stand steel factory of khuzestan was considered as the polluted site and shush region was considered as the control site, and sampling was carried out from the two sites, accide...
Seasonal changes in antioxidant enzymes activities, amount of water, ash, proline and soluble sugars were surveyed during this research in four halophyte species of Varamin County, Tehran, Iran: Salsola turcomanica Litwin, Suaeda arcuata Bunge, Tamarix leptopetala Bunge and Cressa cretica L. Plants were collected randomly from their natural habitats in spring and summer. Activity of these enzym...
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