Proper grazing management practices can generate corresponding compensatory effects on plant community production, which may reduce inter-annual variability of productivity in some grassland ecosystems. However, it remains unclear how grazing influences plant community attributes and the variability of standing crop. We examined the effects of sheep grazing at four stocking rate treatments [control, 0 sheep ha(-1) month(-1); light (LG), 0.15 sheep ha(-1 )month(-1); moderate (MG), 0.30 sheep ha(-1) month(-1); and heavy (HG), 0.45 sheep ha(-1) month(-1)] on standing crop at the community level and partitioned by species and functional groups, in the desert steppe of Inner Mongolia, China. The treatments were arranged in a completely randomized block design over a 9-year period. Standing crop was measured every August from 2004 to 2012. Peak standing crop decreased (P < 0.05) with increasing stocking rate; peak standing crop in the HG treatment decreased 40 % compared to the control. May-July precipitation explained at least 76 % of the variation in peak standing crop. MG and HG treatments resulted in a decrease (P < 0.05) in shrubs, semi-shrubs, and perennials forbs, and an increase (P < 0.05) in perennial bunchgrasses compared to the control. The coefficients of variation at plant functional group and species level in the LG and MG treatments were lower (P < 0.05) than in the control and HG treatments. Peak standing crop variability of the control and HG community were greatest, which suggested that LG and MG have greater ecosystem stability.
Based on the sequence of an expressed sequence tag, the full-length cDNA of 1,008 nucleotides was cloned from Ammopiptanthus mongolicus by rapid amplification of cDNA ends. It was designated as AmDHN, encoding a protein of 183 amino acids. The calculated molecular weight of the AmDHN protein is 18.4 k Da, and theoretical isoelectric point is 5.78. The AmDHN localized in nucleus. Under normal growth conditions, differential expression of AmDHN exhibited that the expression was the highest in seeds and the lowest in flowers. AmDHN could be induced by NaCl, PEG6000, ABA and drought treatments. Salt and drought resistances of transgenic plants with overexpression of AmDHN are improved. Taken together, these results demonstrated that AmDHN could regulate the expression of abiotic-responsive genes and plays important roles in modulating the tolerance of plants to abiotic stresses.
The aim was to study the frequencies of common deafness-related mutations and their
contribution to hearing loss in different regions of Inner Mongolia. A total of 738
deaf children were recruited from five different ethnic groups of Inner Mongolia,
including Han Chinese (n=486), Mongolian (n=216), Manchurian (n=24), Hui (n=6) and
Daur (n=6). Nine common mutations in four genes (GJB2, SLC26A4, GJB3
and mitochondrial MT-RNR1 gene) were detected by allele-specific PCR
and universal array. At least one mutated allele was detected in 282 patients.
Pathogenic mutations were detected in 168 patients: 114 were homozygotes and 54 were
compound heterozygotes. The 114 patients were carriers of only one mutated allele.
The frequency of GJB2 variants in Han Chinese (21.0%) was higher
than that in Mongolians (16.7%), but not significantly different. On the other hand,
the frequency of SLC26A4 variants in Han Chinese (14.8%) was lower
than that in Mongolians (19.4%), but also not significantly different. The frequency
of patients with pathogenic mutations was different in Ulanqab (21.4%), Xilingol
(40.0%), Chifeng (40.0%), Hulunbeier (30.0%), Hohhot (26.3%), and in Baotou (0%). In
conclusion, the frequency of mutated alleles in deafness-related genes did not differ
between Han Chinese and Mongolians. However, differences in the distribution of
common deafness-related mutations were found among the investigated areas of Inner
Mongolia.
Sufficient and accurate air pollutant data are essential to analyze and control air contamination problems. An orthogonal polynomial fitting (OPF) method using Chebyshev basis functions is introduced to produce spatial distributions of fine particle (PM2.5) concentrations in central and southern regions of China. Idealized twin experiments (IE1 and IE2) are designed to validate the feasibility of the OPF method. IE1 is designed in accordance with the most common distribution of PM2.5 concentrations in China, whereas IE2 represents a common distribution in spring and autumn. In both idealized experiments, prescribed distributions are successfully estimated by the OPF method with smaller errors than kriging or Cressman interpolations. In practical experiments, cross-validation is employed to assess the interpolation results. Distributions of PM2.5 concentrations are well improved when OPF is applied. This suggests that errors decrease when the fitting order increases and arrives at the minimum when both orders reach 6. Results calculated by the OPF method are more accurate than kriging and Cressman interpolations if appropriate fitting orders are selected in practical experiments.
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