Entity

Time filter

Source Type


Zhang H.,Gansu Agricultural University | Zhang H.,Chnese Academy of Agricultural science CAAS | An T.W.,Sichuan Academy of Grassland Science | He J.W.,Gansu Agriculture Technology College | And 3 more authors.
Asian Journal of Animal and Veterinary Advances | Year: 2012

Domestic yak plays a critical role in supporting the livelihoods of nomads in the Central Asian Highlands. Tianzhu White yak is a unique breed developed from a very small number of mutant founders and its white hair has a special niche market value. In this study, the genetic polymorphisms in Tyrosinase (TYR) gene, which has been considered as a 'albino locus' in cattle, were identified and characterized to search for alleles associated with the white coat colour in yak. A total of 973 yak samples were collected, including 438 animals from five nucleus breeding herds and 365 individuals from four reproductive herds of the Tianzhu White yak. The reference TYR genomic DNA sequence derived from a Hereford bull was used to design all primers for screening and sequencing the exon 2 and the last partial 5'-untranslated region (5'-UTR) of the yak TYR gene. Both PCR-SSCP analysis and DNA sequences for their complete exon 2 in selected samples from the Tianzhu White yak herds and black yak populations identified a single conserved sequence identical to other cattle breeds. There were 14 genotypes and seven alleles defined by nucleotide polymorphisms present in the 215 bp long 5'-UTR of yak TYR gene among all yak samples, of which five alleles were specific to yak while the other two alleles were of a cattle origin. Although, current data suggested no association of these polymorphisms with the yak coat colour variations, they shed light on the potential function of the promoter on regulation of expression of yak TYR gene that is warranted to screen for additional polymorphisms in its extended 5'-UTR and other exons. © 2012 Academic Journals Inc. Source


Wang X.F.,Lanzhou University | Wang X.F.,Gansu Agriculture Technology College | Li R.Y.,Lanzhou University | Li X.Z.,Chinese Academy of Sciences | And 4 more authors.
Science China Earth Sciences | Year: 2014

In this study, 39 leaf samples of three angiosperms (Betula albo-sinensis, tree species; and Caragana jubata and Berberis diaphana, shrub species) were collected in the middle-east parts at 2300-3640 m asl of the Qilian Mountains to study the variations of leaf characteristics of angiosperms with altitude change in inland high-altitude regions of China. Five leaf indexes, viz. epidermal cell density (ED), stomatal density (SD), stomatal index (SI), leaf vein density (VD) and carbon isotopic ratio (δ13C), were analyzed in laboratory. The results show that there are significant or even very significant linear correlations between the five indexes and altitude, of which SD, SI and VD exhibit a negative correlation with altitude, while ED and δ13C exhibit a positive correlation with altitude. Such a correlation assemblage is quite different from the situation in the low-altitude humid environment. Generally, only an assemblage of positive correlations can be observed between the indexes (viz. SD, SI and δ13C, etc.) and the altitude in the low-altitude humid environment, which were caused mainly by the plants' responses to the change of atmospheric CO2 concentration (Ca). However, an assemblage of the negative and positive correlations found here may be attributed mainly to the plants' responses to the change of physiological drought caused by change of low temperature, and here it is preliminarily called the inland high-altitude pattern of plant leaf variations. © 2014 Science China Press and Springer-Verlag Berlin Heidelberg. Source


Zhang J.,Lanzhou Resources and Environment Voc Technology College | Leng Y.,Lanzhou Resources and Environment Voc Technology College | Liu J.,Gansu Agriculture Technology College | Wang Y.,Northwest Normal University
Computational and Theoretical Chemistry | Year: 2015

A computational study of the oxygen-transfer reaction of N2O and H2 catalyzed by IrOn+(n=0-2) is completed, incorporates two possible reaction pathways along with quintet and triplet states. In this work, density functional theory method is used to determine all possible intermediates, transition states and products. The crossing points with the possible spin inversion processes are discussed using the intrinsic reaction coordinate approach. According to the calculated results of O-atom affinities, we predict that the 5/3IrOn+(n=0-2) has good O-transfer function from N2O to H2. © 2015. Source


Zhang J.,Gansu Agricultural University | Zhang G.,Gansu Agriculture Technology College
Acta Horticulturae | Year: 2010

Thirty-four cultivars or strains including 4 edible seed watermelons, 2 wild watermelons and the different ecology type of flesh watermelons were evaluated for genetic relationships using the data of characteristics of plant in growth period and the fruit, the seed size, RAPD mark and cluster analysis. The results showed that the seed size, development period of fruit and soluble solid content of flesh etc. of 'Jingyuandaban' had obvious differences from flesh watermelons, most of them were extreme type. The other 3 cultivars of edible seed watermelons, 'Neimengbaiguazi', 'Ninghong' and 'Xinhong', also had similar differences from the flesh watermelon but the range of differences was smaller; 16 random primers were used in this study revealing 157 RAPD markers in the 34 cultivars. A total of 67 (42.68%) of the 157 RAPD markers were polymorphic. 34 cultivars or strains were classified into two sub-groups, which were cultivars and wild types, the genetics distances of most cultivars were small. The genetic distances between edible seed watermelon and flesh watermelon were not beyond the biggest genetic distance among flesh watermelons. That meant that edible seed watermelons were not suitable as an independent variation from flesh watermelon (var. vulgaris of sp. Vulgaris (Schrad.) Fursa.). Source


Zhang R.,Lanzhou University | Zhang R.,Gansu Agriculture Technology College | Li Y.,Lanzhou University | Qi J.,Lanzhou University | Gao D.,Lanzhou University
Nanoscale Research Letters | Year: 2014

Two-dimensional materials have various applications in the next generation nanodevices because of their easy fabrication and particular properties. In this work, we studied the effects of crystalline order on the magnetic properties of ultrathin MoS2 nanosheets. Results indicate that all the fabricated samples show clear room temperature ferromagnetism. The amorphous sample has the larger saturation magnetization than that of the crystallized samples, where the disordered grain boundary or defects in the nanosheets are considered to be responsible for the long-range magnetic order. These MoS2 nanosheets with versatile functions may have potential applications in spintronics, nanodevices, and photodevices. © 2014, Zhang et al.; licensee Springer. Source

Discover hidden collaborations