The focus of the present study was to investigate the chemical composition of essential oil of Salvia hydrangea DC. ex Benth. growing wild in Kiasar-Hezarjrib, Iran. In addition, effects of altitude and some soil properties on the essential oil quality and quantity of S. hydrangea was identified. The samples collected from two altitudes (1100 and 2000 m) in blossoming period, were analyzed by h...

Dense satellite constellations recently emerged as a prominent solution to complementing terrestrial networks in attaining true global coverage. As such, analytic optimization techniques can be adopted rapidly maximize the benefits of such networks. This letter presents framework that relies on two primary tuning parameters optimize uplink performance; (i) constellation altitude and (ii) antenn...

Studies aiming at explaining specialization along latitudinal gradients of plant-herbivore interactions have, to date, yielded inconclusive results. Here we propose the use of steep altitudinal gradients for dissecting factors driving evolution of polyphagy in insect herbivores. First, we test whether colonization of high elevation environment favours increased niche-breadth in two disparate in...

Characterization and extraction of plant secondary metabolites are important in agriculture, pharmaceutical, and food industry. In this regard, the applied analytical methods are mostly costly and time-consuming; therefore, choosing a suitable approach is essential for optimum results and economic suitability. One of the recently considered methods used to characterize new types of materials is...

Medicinal plant species constitute a considerable part of the flora in Iran and play a major role in the composition of plant communities. Therefore, it is necessary to recognize the factors leading to the establishment and distribution of vegetation. For data sampling (2012), land units were specified. The plot size was determined using minimal area method and number of plots was determined by...

Any work activity performed at elevations over 3,000 m above sea level is considered as work at high altitude. The changing environmental conditions result in an adaptation of the human organism, mainly due to a reduced partial pressure of oxygen in the air and a proportional decrease in barometric pressure. We carried out a systematic review of the scientific literature in this field so as to ...

Global change is exerting a major effect on plant communities, altering their potential capacity for adaptation. Here, we aimed at unveiling mechanisms of adaptation to high altitude in an endemic long-lived monocarpic, Saxifraga longifolia, by combining demographic and physiological approaches. Plants from three altitudes (570, 1100, and 2100 m above sea level [a.s.l.]) were investigated in te...