introduction the main challenge for health in twenty century was survival, but in the new century the life with a better quality is an important matter. aging is an emotion period in human life and attention to needs in this period is a social necessity. therefore, attention to the quality of life of elders is very important in the social policy. the number of the elderly is increasing across t...

dormancy breaking of field maple (acer campestre l.) seed, by gibberllic acid (ga3) at 0, 250, 500 and 1000 ppm in 24 and 48 hours and stratification treatments in moist sand under warm (18-20 °c) and cold (2-4°c) conditions were investigated. effects of ga3 and stratification and their interaction on germination percent (gp) and germination speed (gs) were significant. the highest gp occurred ...

introduction climate change happens due to abnormal changes of climate within the earth’s atmosphere and their consequences. one of the most significant effects of climate change is the irreversible damage to some floral species and forest ecosystems. tree species reflect the impact of climate changes on their ring width. generally, tree rings vary in size each year depending upon the environme...

the effect of gibberellic acid (ga3) spraying on some characteristics of cyclamen flowering trend during the second flowering year was investigated. ga3 sprays were applied in concentrations of 0, 20, 30, 40, and 50 mg/l. the trial was carried out as a randomized complete design of three replications. the total flower count, flower count during the flowering peak, days from spraying to flowerin...

drought as a climatic phenomenon affected many different environmental issues and generally is associated with the decreasing in average precipitation. evaluation and monitoring of the drought is a fundamental step in proper programming of water resources management. regarding the recent conditions water scarcity in the urmia lake basin, assessment of the drought index in this region is inevita...

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forest cover is one of the most effective factors in reducing flooding in northern iran, so that in recent years the destruction, land use changing and uncontrolled harvesting of forest areas, has greatly increased the number and magnitude of floods. so far, there have been few studies on forest hydrology in iran, particularly the northern hyrcanian forests. this study examines the impact of a ...

decreasing water loss and increasing the irrigation times are basic methods to develop agriculture, success in natural recourse projects, minimize the stress to planted bushes in natural fields and increase the productivity of soil and water sources. the use of super absorbent is one of these strategies to achieve these goals. the main purpose of this research was to study the effect of super a...

objective: angiogenesis a process that results in neo-vascularization is an essential stage in growth of solid tumors and the formation of metastases. vascular endothelial growth factor (vegf) and its receptors, vegfr1 (flt-1) and vegfr2 (kdr/flk-1), are the major regulators for tumor angiogenesis. recent studies showed that second domain of vegfr-1is a key factor for vegf/vegfr-1 interaction. ...

hybrid-density functional theory (b3lyp/def2-tzvpp) based method and nbointerpretation were used to investigate the conformational behavior of 1,2-dihalodisilanes[halo=f (1), cl (2), br (3), i (4)]. the b3lyp/def2-tzvpp results showed that the anticonformations of compounds 1-4 are more stable than their corresponding gaucheconformations. the stability of the anti conformation compared to the g...