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Mitochondrial cytochrome b gene sequences and morphological data (body length, hind foot length, etc.) for twelve populations with pairwise distances 27–600 km in Qinghai-Tibetan Plateau (distributed in Qinghai, Gansu and Sichuan Province, and at the altitude 3020–4550 m) in Western China were used to investigate the phylogeographical pattern of Plateau zokor (Myospalax baileyi Thomas). There was a little disparity between mtDNA genetic distance and morphological Euclidean distance on population relationships. However, there is a significant correlation (P <0.001) calculated by Mantel’s tests was validated between mtDNA and morphology distances. Analysis of Molecular Variance showed that most of the observed genetic variations occurred between populations, indicating little maternal gene flow between them, as a result of geographical restrictions. Phylogenetic analysis coupled with cluster analysis together showed that the substantial population structuring and phylogenetic discontinuities existed within this species. The evident allopatric population structuring of this subterranean rodent may mostly result from its specialized subterranean excavating behavior with high energy costs, predation from grassland raptors and also the influences of perennial tundra and environmental desiccation in the Qinghai-Tibetan Plateau.
Themus (T.) senensis (Pic, 1922) is redescribed and three new species related to it are described, T. (T.) senensomimus sp. nov. (China, Thailand), T. (T.) bilobatus sp. nov. (Laos, Vietnam) and T. (T.) dalatensis sp. nov. (Vietnam). Each species is provided with illustrations of aedeagus and abdominal sternite VIII of female. T. (T.) senensis is also presented with female genitalia and the new species with habitus of both sexes. A key and a distribution map of the above four species are presented.
To solve the problem of low precision of numerical simulation of the exposed reinforced anti-corrosion layer damage of the cross-sea bridge, we use the stress ratio between the double slash and the reinforced anti-corrosion layer to analyze the parameters and the damage rate in different qualities of reinforced anti-corrosion layers, use Ansys software to build reinforced finite element model, and analyze the damage degree when the inclination angle was 15 °, 45 ° and 60 °, respectively. The experimental results showed that the proposed method can improve the numerical simulation efficiency, the numerical simulation results, the experimental results, and the theoretical analysis results have good consistency and stability
The variations in leaf traits of Taxus species in different light conditions are still poorly understood. We sampled leaves of Taxus yunnanensis W. C. Chang L. K. Fu and Taxus chinensis var. mairei (Lemée and Lév.) W. C. Cheng and L. K. Fu along an illumination gradient (full daylight, 40–60% full daylight, <10% full daylight), and analyzed how seven leaf traits and their correlations changed under different light conditions. The leaf trait that showed the greatest variation was specific leaf area (SLA) for T. yunnanensis, followed by leaf dry mass (LM) for both taxa. The smallest variation was in leaf width (LW) for both taxa. Plasticities of all leaf traits in both taxa were higher than 50%, and those of leaf area (LA), LM and SLA were greater than 80%. The light gradient was positively correlated with leaf length (LL), LM, leaf dry matter content (LDMC), and leaf length to width ratio (LWR). LW and SLA were negatively correlated with the light gradient. Analyses of relationships among leaf traits showed that LM of T. yunnanensis, T. chinensis var. mairei and both taxa was positively correlated with LL, LW, LA, LDMC, and LWR, and negatively correlated with SLA under all light conditions. We concluded that leaf traits and their relationships were affected by light conditions.
A total of 449 plateau pika (Ochotona curzoniae Hudgson) individuals were sampled with rattraps from 21 plots (size 1 ha) randomly scattered over the area of the species distribution at the altitude 3275–4807 m a.s.l. in the Qinghai-Tibetan Plateau (West China). Two main ectoparasite species Hypoderma satyrus Brauer and Ixodes crenulatus Neumann of plateau pika were surveyed, and the relations between host sex and parasitism were analyzed. The results were: (i) although not significantly, the infection rate of female young was close to zero and lower than that of male young (6%), while the infection rate of female sub-adults (19%) was contrarily – higher than that of male sub-adults (11%); adult females had significantly higher (41%) infection rate than that of males (18%) (P <0.001); (ii) the parasite infection rates for both males and females increased with increasing age, but female age-groups had obviously steeper slope. We suggested that the differences of body mass, growth rate and home range between males and females had mainly caused the sex-biased parasitism (SBP) of plateau pika at each age stage. Also, due to the higher increases of body mass and maybe as well as of the home range differences between consecutive age-groups, the parasite infections of females became more sensitive to the influences of age than that of males.
Summer diets of two sympatric raptors Upland Buzzards (Buteo hemilasius Temminck et Schlegel) and Eurasian Eagle Owls (Bubo bubo L. subsp. Hemachalana Hume) were studied in an alpine meadow (3250 m a.s.l.) on Qinghai- Tibet Plateau, China. Root voles Microtus oeconomus Pallas, plateau pikas Ochotona curzoniae Hodgson, Gansu pikas O. cansus Lyon and plateau zokors Myospalax baileyi Thomas were the main diet components of Upland Buzzards as identified through the pellets analysis with the frequency of 57, 20, 19 and 4%, respectively. The four rodent species also were the main diet components of Eurasian Eagle Owls basing on the pellets and prey leftovers analysis with the frequency of 53, 26, 13 and 5%, respectively. The food niche breadth indexes of Upland Buzzards and Eurasian Eagle Owls were 1.60 and 1.77 respectively (higher value of the index means the food niche of the raptor is broader), and the diet overlap index of the two raptors was larger (Cue = 0.90) (the index range from 0 – no overlap – to 1 – complete overlap). It means that the diets of Upland Buzzards and Eurasian Eagle Owls were similar (Two Related Samples Test, Z = –0.752, P = 0.452). The classical resource partitioning theory can not explain the coexistence of Upland Buzzards and Eurasian Eagle Owls in alpine meadows of Qinghai-Tibet Plateau. However, differences in body size, predation mode and activity rhythm between Upland Buzzards and Eurasian Eagle Owls may explain the coexistence of these two sympatric raptors.
Jasmine [Jasminum sambac (L.) Aiton] growth and development is affected by long-term shade. To determine the effects of short-term shade on jasmine physiology, the contents of soluble proteins, malondialdehyde (MDA) and antioxidative enzymes were comparatively investigated during 24 h (short-term, ST) and 7 days (medium-term, MT) of varying light regimes. The results showed that the protein content exhibited two peaks under ST treatment, and shade postponed the first peak 2 h later than full light. On the whole, protein synthesis was reduced by ST shade and induced by MT shade, whereas MDA content decreased during all shade treatments. Under ST shade, superoxide dismutase (SOD), peroxidase (POD) and ascorbate peroxidase (APX) activities were enhanced, but catalase (CAT) activity was repressed by limited irradiances. However, the antioxidant enzymes responded differently—SOD activity increased after 2 h of shading and then kept on a high level, whereas POD, APX and CAT activities increased mainly during the first hour and deceased subsequently. Under MT shade, these antioxidative enzymes responded differently to varying light irradiances, too. In general, POD and CAT activities were repressed, SOD activity was induced by weak (50% irradiance) shade and reduced by moderate (20% irradiance) and severe (5% irradiance) shade. APX activity was rather more complicated and irregularly responded to different degrees and durations of shade, meaning it might not be the main enzyme to remove ROS in jasmine plants under shading condition. The increase protein content with prolonged shade represents the sound adaptive ability of jasmine plants to restricted irradiances. At the same time, rapid changes in proteins and antioxidants reflect the efficient metabolic apparatus of the plant in response to shade. Therefore, the jasmine cultivar is shade tolerant. Furthermore, shade could help the plants protect themselves from full light, and some degrees of shade were beneficial to their antioxidant system. However, severe shade (5% of irradiance) is only suggested for a few hours to protect the plants at solar noon. If the plants are continuously shaded for 3–7 days, weak (20%) to moderate (50%) level of irradiance should be applied.
Kozlov’s pika is a rare and endangered lagomorph species with a limited distribution in the southern Kunlun Mountains in western China. Because of its endangered status, Kozlov’s pika is considered a priority species for research and conservation action. Genetic variation and molecular evolution of the Kozlov’s pika were studied based on a total of 14 individuals from four locations along the eastern boundary between Xinjiang and Tibet province (35.20–36.48°N, 86.08–83.04°E) on extremely high elevation (usually over 4800 m a.s.l.). The density of local populations was about 3–4 per ha, living in a typical alpine desert grassland habitat. The complete mitochondrial cytochrome b (cytb) gene was amplified and sequenced. Based on the cytb gene sequences the genetic variation and molecular evolution were analyzed. Unexpected high haplotype diversity (0.956 ± 0.045) but low nucleotide diversity (0.00537 ± 0.00126) was found, indicating past demographic expansion. Significant partitioning of variance (P <0.01) among populations (46.7%), and within populations (53.3%), indicating low level of genetic differentiations among local populations. Our results gave an optimistic survival status of Kozlov’s pika at the genetic level. Bayes Empirical Bayes analysis with model M2a and M8 detected three positively selected amino acid sites at the significance level of 0.05. The mutant types with either or both of the mutations aspartic acid to asparagine and glutamic acid to lysine had higher isoelectric point values. We suggested these mutant types might have biological significance to help individuals to adapt to the extremely high elevation habitats.
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