Hypothermic and hypoxic environments create strong selective pressure on native species by affecting, among other things, the relationship between energy intake and allocation. In order to detect the adaptation of Phrynocephalus vlangalii to such energy limitation, the morphological structure and argyrophil cells of the digestive tract of 80 individuals from two different altitudes in the Qinghai-Tibet Plateau were compared using overall anatomy as well as paraffin sectioning of specific organs. Compared with the low-altitude population, the high-altitude individuals were found to have a significantly longer stomach and duodenum, longer and wider villus in the small intestine, larger surface area in duodenum and jejunum, and more argyrophilic cells in stomach and duodenum. Our results indicate that the morphological and histological change of the digestive tract may be conductive to the plateau adaptability of P. vlangalii by enhancing the efficiency of digestion and absorption. For a more general conclusion to be drawn, comparison of more populations at both altitudes is required in addition to verifying how phenotypically flexible these traits are.
As an empirical study based on undergraduate ratings of 2364 teachers lecturing in different courses during four semesters in Beijing Normal University, this paper studies the relationship between teaching effectiveness and research productivity. The results show that both of them are positively correlated, that is to say, teaching effectiveness benefits from research productivity.
Pine wilt disease (PWD) is a devastating pine disease caused by Bursaphelenchus xylophilus and its main host in China is Pinus massoniana. The relationship between endophytic bacteria and disease resistance in P. massoniana remains unclear. In this paper, the leaves, roots, stems and treetops of different disease-resistant P. massoniana were studied as the research objective and Illumina MiSeq sequencing was used to analyse whether there were significant differences in the composition and diversity of endophytic bacterial communities between different disease-resistant P. massoniana. The results showed that at the genus level there were no obvious differences in the composition of the endophytic bacterial community of different disease-resistant P. massoniana in the leaves, but there were obvious differences in the roots, stems and treetops. The richness and diversity of endophytic bacteria in P. massoniana had no significant impact on its disease resistance, whilst the structure of endophytic bacterial community in stems and treetops may be related to its disease resistance.
The oriental river prawn, Macrobrachium nipponense, is one of the important commercial shrimp species. Recently a severe problem of precocious maturation has greatly hampered this shrimp aquaculture industry. Bisphenol A (BPA), a high-production-volume chemical substance used in the plastic manufacturing industry, has been thought of as an endocrine disruptor on the developmental processes of animals. In this study, we investigated the effect of BPA exposure on the expressions of five ovary development related genes such as Mago nashi, Tsunagi, Gustavus, Ubc9, and Von Willebrand factor D-Kazal in M. nipponense. Five concentration gradients (5.01, 7.76, 12.06, 18.62 and 28.84 mg/l) of BPA were set and the ovaries of exposed prawns were collected at different time points for expression analysis. Compared with the control group at day 19, BPA had a two-phase effect: a stimulating effect under low concentrations from 5.01 to 12.06 mg/l, whereas a negative effect was noted at high concentrations from 12.06 to 28.84 mg/l. The expression profiles under different BPA concentrations significantly changed along with the extension of exposure time. The medium concentration of BPA (12.06 mg/l) had a persistent influence on the expressions of the transcripts, while the effect was transient under the lowest concentration (5.01 mg/l). It is suggested that the concentration under 5.01 mg/l might be safe for the development of M. nipponense, but exceeding 12.06 mg/l may be harmful. When exposed to clean fresh water without BPA, the gene expressions rebounded a little. This may indicate that the biological damage of BPA was partly reversible after the prawns had been placed in the fresh water without BPA. So the BPA pollutant concentration should be controlled at secure levels in order to ensure safety in aquaculture, in this respect. This study provides fundamental data for the relationship between BPA and precocious maturation of the prawn, and will most probably contribute to the understanding of the sexual maturation process in crustaceans.
Regurgitated pellets (n = 584) of Long-eared Owl (Asio otus) were collected for three seasons from Gansu Endangered Animal Research Center, Gansu Province, China. From these pellets, a total of 1011 individual prey items – representing seven species of rodents and two undetermined species of birds and one undetermined sorex-species – were identified. Long-eared Owls depend mainly on small mammals both based on prey numbers (95.5%) and prey biomass (97.0%). The composition of the diet of Long-eared Owls varied significantly among seasons by frequency and by biomass. The individual species groups indicated significant variation among seasons for Mus musculus, Meriones meridianus, Cricetulus barabensis, Phodopus roborovskii, Dipus sagitta and Rattus norvegicus by biomass. And the difference of seasonal variation of prey items were significant but not for Mus musculus by frequency. Based on prey numbers, Mus musculus was the main food item (50.5%) in its diet; this species was most common in autumn (56.9%) and least common during spring (36.7%). Main prey species, based on prey biomass, was Rattus norvrgicus which comprised 27.5% of total biomass from our pellet samples. The mean length of tibias of mammals in pellets of Long-eared Owls was 18.6 ± 5.4 mm. Long-eared Owls utilize a wide range of prey items in respect to their habitats. Results suggest that Long-eared Owls are selective predators at some levels.
The third-stage dispersal juvenile (JIII) is the stage for survival and
dispersal in the winter of the pine wood nematode, Bursaphelenchus
xylophilus. Through investigations at different temperatures, we found two
kinds of growth-arrested development, including the adult longevity
extension and JIII formation induced by low temperature. They showed similar
characters: densely packed lipid droplets and extended longevity. We
considered that there were four stages in the formation of growth-arrested
stages: induction, growth-arrested pathway, growth-arrested development and
cold-tolerance duration. Moreover, at 4°C there were significant changes in
secondary metabolites, which may be related to signal communication and
metabolism associated with the formation of growth-arrested stages. The
results suggested that low temperature was necessary for the dispersal of
pine wood nematode and influenced distribution and intensity of pine
The plateau zokor (Myospalax baileyi) is a specialized subterranean rodent that lives on the Qinghai-Tibet Plateau. The species has evolved a series of strategies to adapt to its hypoxic environment and hypercapnia. p53 is a tumour suppressor gene that plays a crucial role in the cellular response to hypoxia by inducing cell cycle arrest, cell apoptosis, DNA damage repair and angiogenesis. To investigate the sequence characteristics of p53 and the response to hypoxia in plateau zokor, we cloned the p53 coding DNA sequence, analysed it, and measured the expression level of p53 at different altitudes in plateau zokor and rats. Our results show that the coding DNA sequence is 1179 bp, consisting of 392 amino acid residues. Compared to human p53, the subterranean rodents have two mutation sites in common with the human hotspots in the DNA-binding domain. Compared to subterranean rodents, plateau zokor have a mutation at residue 309. In addition, subterranean rodents have two convergent sites at residues 78 and 84. The expression levels of p53 in plateau zokor tissues increase significantly from 2260 m to 3300 m, but there was no significant difference in rats at those altitudes. Our results suggest that subterranean rodents have two mutation sites in common with the human hotspots in the DNA-binding domain, the mutation of Gly309Asp is a unique mutation site of plateau zokor p53, and there are two convergent sites enhancing subterranean rodent adaptation to hypoxic conditions. In addition, p53 is sensitive to the oxygen concentration in plateau zokor, and hypoxia upregulates the levels of p53. Generally, plateau zokor use this strategy to adapt to a hypoxic environment.
We compared diets of little owls (Athene noctua) and long-eared owls (Asio otus) in the Minqin Desert in northwestern China. Based on prey numbers, little owls fed mainly on mammals (51.0%) and beetles (46.9%), whereas long-eared owl fed almost exclusively on mammals (96.4%). Based on biomass, both species fed mainly on mammals. Mus musculus, Cricetulus barabensis and Meriones meridianus were the three most common mammals taken by both species. Seasonal variation was found in the diets of both species. Food niche breadth was 3.4 for little owls vs 2.9 for long-eared owls. Dietary overlap between the two species was 49.6%, but varied from 4.0% in April to 96% in January. Dietary overlap of mammals was 97.9%, indicating that both owls fed on similar rodent assemblages. Mean mass of prey was 25.8 ± 22.7 g for long-eared owls and 15.5 ± 22.7 g for little owls. The mean length of tibias of mammals in pellets also indicted that, on average, long-eared owls (18.1 ± 5.6 mm) took larger prey than little owls (16.2 ± 4.7 mm).
This article focuses on the serious occupational health and safety (OHS) injuries affecting the workers of one of China’s most important industries—automotive assembly—and particularly the musculoskeletal disorders (MSDs) that are common in the industry. The data are drawn from a 2011 survey of 1,100 autoworkers conducted at twelve assembly plants in seven Chinese cities. By correlating injury rates with age, speed of the assembly line, length of work hours, mental pressure, availability of floaters to replace absent workers, ease to take sick leave, etc., the data identify the most salient causes of MSD. The study raises the issue that the state and management’s ignoring of MSD and the lack of workers’ participation and representation in the plants constituted a violation of labor rights. The article offers some remedies that are applicable both in China and internationally.