نتایج جستجو برای: desert
تعداد نتایج: 15468 فیلتر نتایج به سال:
an experiment was conducted in algerian desert goats to study the effect of age and season on blood biochemical and mineral profile during different physiological stages of the goats. serum ca, mg and na levels were significantly high at birth and decreases as the age advanced. the season had a significant effect on the decreased levels of ca, mg and k and inversely on the increased levels of n...
desert truffles, hypogeous pezizales (ascomycota), are difficult to identify due to evolutionary convergence of morphological characters among taxa that share a similar habitat and mode of spore dispersal. in this paper we document the presence of picoa lefebvrei (pat.) maire (=phaeangium lefebvrei) in iran and use phylogenetic analysis of the its and 28s rdna to show that this species belongs ...
still your go-to example of a missing link? Well, it turns out that palaeontology has made great strides since you were at school and there are now numerous beautiful examples of transitional forms, from fossilised creatures linking land and marine mammals to half-ant-half-wasps preserved in amber and many others. What is more, these transitional forms are always dated to the right point in his...
Isotopic analysis of nitrate and sulfate minerals from the nitrate ore fields of the Atacama Desert in northern Chile has shown anomalous O enrichments in both minerals. O values of 14–21 ‰ in nitrate and 0.4 to 4 ‰ in sulfate are the most positive found in terrestrial minerals to date. Modeling of atmospheric processes indicates that the O signatures are the result of photochemical reactions i...
The goal of this study was to gain insight into the diversity of culturable actinobacteria in desert soil crusts and to determine the physiological characteristics of the predominant actinobacterial group in these crusts. Culture-dependent method was employed to obtain actinobacterial strains from desert soil samples collected from Shapotou National Desert Ecological Reserve (NDER) located in T...
Biogeosciences Discussions This discussion paper is/has been under review for the journal Biogeosciences (BG). Please refer to the corresponding final paper in BG if available. Abstract Atmospheric concentrations of reactive nitrogen species (Nr) from 2009 to 2011 are reported for ten sites in Xinjiang, an arid region in Northwest China. Concentrations of NH 3 , NO 2 , particulate ammonium and ...
Desert tortoises (Testudines; Testudinidae; Gopherus agassizii group) have an extensive distribution throughout the Mojave, Colorado, and Sonoran desert regions. Not surprisingly, they exhibit a tremendous amount of ecological, behavioral, morphological and genetic variation. Gopherus agassizii was considered a single species for almost 150 years but recently the species was split into the nomi...
Spatial and temporal patterns of Holocene vegetation and climate changes in arid and semi-arid China
Pollen data from 30 sites in arid and semi-arid regions of China were reviewed to document regional patterns of Holocene vegetation and climate change and to understand the large-scale controls on these changes. Vegetation at most sites in eastern Inner Mongolia switched between forest, forest steppe, and typical steppe, showing maximum moisture conditions before 6 ka (1 ka 1⁄4 1000 cal yr BP) ...
Agassiz's desert tortoise (Gopherus agassizii) is a long-lived species native to the Mojave Desert and is listed as threatened under the US Endangered Species Act. To aid conservation efforts for preserving the genetic diversity of this species, we generated a whole genome reference sequence with an annotation based on deep transcriptome sequences of adult skeletal muscle, lung, brain, and bloo...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید