Dietary selection and intake affect the survival and health of mammals under extreme environmental conditions. It has been suggested that dietary composition is a key driver of gut microbiota ...variation; however, how gut microbiota respond to seasonal dietary changes under extreme natural conditions remains poorly understood. Sequencing plant trnL (UAA) region and 16S rRNA gene analysis were employed to determine dietary composition and gut microbiota in freely grazing yaks on the Tibetan plateau. Dietary composition was more diverse in winter than in summer, while Gramineae and Rosaceae were consumed frequently all year. Turnover of seasonal diet and gut microbiota composition occurred consistently. Yaks shifted enterotypes in response to dietary change between warm and cold seasons to best utilize nitrogen and energy, in particular in the harsh cold season. Our findings provide insights into understanding seasonal changes of diet-microbiota linkages in the adaptation of mammals to high altitudes.
•Aboveground biomass and vegetation coverage decreased with degradation successions.•More forbs and less grasses and sedges occurred with degradation successions.•Significant differences in soil ...nutrients showed in 0–20 cm with degraded processes.•Non-grazing increased vegetation cover, aboveground biomass and soil nutrients.•Soil nutrients were affected by aboveground vegetation.
Understanding the changes in vegetation parameters and soil nutrients in the different stages of grasslands degradation and recovery is crucial for assessing and restoring degraded grasslands. Consequently, we determined above-ground vegetation and soil C, N and P concentrations and their stoichiometry in different degradation and recovery stages on the Tibetan Plateau. Four degradation succession stages, GKC: Grass-Kobresia community, KHC: Kobresia humilis community, KPC: Kobresia pygmaea community, and FBC: forbs - black soil beach community, and three recovery succession stages, FG: freely grazed, RG: restricted grazed, and NG: non-grazed, were identified. Above-ground biomass and vegetation coverage decreased with degradation succession and there was a concomitant shift of plant functional groups to more above-ground biomass of forbs and less biomass of grasses and sedges. The highest species diversity emerged in the K. pygmaea succession stage, mainly due to an influx of Compositae. Significant differences in soil total nitrogen (TN), total phosphorus (TP) and soil organic carbon (SOC) concentrations occurred in the 0–10 and 10–20 cm layers among degradation successions. Vegetation cover, above-ground biomass, soil TN and SOC, as well as C:N and C:P ratios increased in non-grazed grasslands when compared to grazed grasslands. Soil TN, TP and SOC concentrations decreased with increasing soil depths across all degradation and recovery successions. In addition, soil nutrients and their stoichiometry were affected by above-ground biomass. We concluded that grazing exclusion could improve the above-ground vegetation and soil nutrients of degraded alpine grasslands, but that the rate of recovery was related to the degree of degradation.
Yaks and indigenous Qaidam cattle and cattle‐yak crosses (C × Y) graze on the Qinghai‐Tibetan Plateau (QTP) throughout the year, but yaks are raised at higher elevations than cattle. Yaks do not ...receive supplementary feed whereas cattle require supplementary feed during harsh winter. We hypothesized that yaks would cope with the severe conditions of the QTP better than cattle and utilize the pasture more efficiently. We also hypothesized that differences between species would be pronounced in winter, when conditions are particularly harsh. To test these hypotheses, seasonal rumen fluid parameters of yaks, C × Y and cattle (n = 3 for each) were examined. Rumen fluid was collected in summer and winter from each genotype 2, 5 and 12 hr after a day of grazing. Concentrations of total volatile fatty acid (VFA), acetate, propionate, isobutyrate and isovalerate were greater in yaks than in cattle in summer (p < 0.05), while propionate concentration was lower in yaks than in cattle in winter (p < 0.05). Concentrations of ammonia and urea were greater (p < 0.001) in yaks than in cattle (p < 0.001) in summer, whereas, concentrations of free amino acids (AA) were greater in cattle than in yaks in summer and winter (p < 0.001). Concentrations of total VFA, acetate, propionate and butyrate decreased linearly (p < 0.05), whereas concentrations of isobutyrate and isovalerate increased linearly for yak and C × Y with sampling time (p < 0.05) in summer. In summer, concentrations of isobutyrate and isovalerate were greater in yaks than in cattle (p < 0.05). In conclusion, rumen fermentation characteristics of yaks showed that they coped better than cattle or C × Y in the harsh climate as we hypothesized. However, in contrast to our hypothesis, this emerged only in summer, when pasture was plentiful and not in winter, when pasture was scarce.
•Fermentation of Tibetan (TBI) and Small-tailed Han sheep rumen inocula (HSI) differed.•CH4 and H2 decreased with an increase in proportion of TBI.•Nutrient digestibilities increased with an increase ...in proportion of TBI.•Ratios of TBI: HSI inocula affected estimated Gibbs energy changes.•Metabolic hydrogen fluxes were shifted by ratios of TBI: HSI inocula.
Tibetan sheep are well adapted to harsh environmental conditions and poor-quality forage and are known to produce less methane (CH4) gas than lowland sheep. In this study, rumen inocula from Tibetan sheep (TBI) and from Small-tailed Han sheep (HSI) were incubated in in vitro batch cultures in five ratios (TBI: HSI): 0:100, 25:75, 50:50, 75:25 or 100:0 for 72 h. With an increasing proportion of TBI, there was a linear decrease (P < 0.001) in gas and CH4 production on a degraded dry matter (DM) basis at 12, 24, 48 and 72 h. In addition, increasing the proportion of TBI increased the digestibility of DM (P < 0.05), neutral detergent fiber and acid detergent fiber and total and individual volatile fatty acids (VFA) concentrations at almost all time points. An increase in the TBI: HSI ratio resulted in less metabolic hydrogen (2H) incorporated into CH4 and more into propionate. The recovery of 2H consistently decreased with an increase in the TBI: HSI ratio, indicating the existence of unaccounted 2H in TBI. It would be important to study the rumen microbiome in Tibetan sheep with the use of classical microbiology and modern –omics techniques to identify 2H sinks alternative to CH4, which could perhaps be stimulated in other domestic ruminants.
The article is devoted to the consideration of the perception of V. Pelevin and the study of his work in China. The object of the study is the perception of Victor Pelevin's creativity in China. The ...subject of the study is a review of translations of V. Pelevin's works into Chinese and a presentation of the results of research about him in Chinese literary criticism. The main purpose of the work is to analyze the degree of study of Victor Pelevin's work in China with a brief overview of the main directions of modern research by Chinese critics. In the work, along with general scientific methods of analysis, synthesis, analogy and generalization, the descriptive method and the comparative method were also used. As a result of the conducted research, it was revealed that Chinese literary critics pay close attention to the work of Viktor Pelevin, especially the Chinese elements in his works, and highly appreciate the intellectual value of the writer's works. The results described in this article will contribute to a deeper understanding of V. Pelevin's work by Chinese literary critics, and can also be introduced as scientific material into the educational process at the Faculty of Philology. The scientific novelty of the research lies in the fact that for the first time new scientific achievements of China are involved in the research field – the evaluation and study by Chinese researchers of the works of V. Pelevin.
The article is devoted to the problem of studying the "Siberian text" of Russian literature through the eyes of Chinese critics. The object of the study is the analysis of the "Siberian text" in ...Chinese literary criticism. The subject of the study is the metaphorical images of Siberia analyzed by Chinese critics in the works of Russian writers of the XVII-XX centuries. The main purpose of the work is to determine the specifics of studying the "Siberian text" of Russian literature with a brief overview of the main directions of modern research by Chinese critics. In the work, along with general scientific methods of analysis, synthesis, analogy and generalization, the following research methods were used: descriptive method, comparative method and method of linguocultural interpretation. The results of the study show that Chinese literary critics pay close attention to the works of classical and new Siberian writers. The main conclusions of the study are the classical images of Siberia and the change in the image of Siberia, as well as the famous writers of various trends and their works are summarized. The scientific novelty of the research lies in the fact that for the first time new Chinese scientific achievements are involved in the research field – the assessments of Chinese researchers about the images of Siberia in Russian literature.
A dual cocatalyst system consisting of Pt and PdS combined with CdS shows exceptionally high quantum efficiency for photocatalytic H2 production. Pt and PdS act as reduction and oxidation cocatalyst, ...respectively. Junctions are formed between the cocatalysts and semiconductor. The co-loading of Pt and PdS can suppress recombination of photogenerated electron-hole pairs, is thus held responsible for the high quantum efficiency. Display omitted
► The essentials of the exceptionally high quantum efficiency (93%) were investigated. ► The mechanism of photocatalytic course was studied by in situ measurement. ► PdS and Pt act as the oxidation and reduction co-catalysts, respectively. ► The recombination of photo-generated charges is suppressed by co-catalysts. ► Atomic junctions between the co-catalysts and CdS are formed.
The essentials of the exceptionally high quantum efficiency (93%) of photocatalytic hydrogen production on Pt–PdS/CdS have been investigated by studying the roles of the dual cocatalysts Pt and PdS in photocatalysis. In situ photoelectrochemical measurements, photoluminescence spectroscopy and high-resolution transmission electron microscopy characterizations indicate that the exceptionally high QE can be attributed to vital factors including PdS and Pt as the oxidation and reduction cocatalysts, respectively; the efficient utilization of the photogenerated electrons, including those at the shallow trap states of CdS, for photocatalytic reactions; and the facial charge transfer between the cocatalysts and CdS through atomic heterojunctions. Combinations of Pt with other metal sulfides and PdS with other noble metals as dual cocatalysts also show an evident synergetic effect on the activity. The co-loading of Pt and PdS on other sulfide semiconductors results in the same enhancement of photocatalytic activity. It is proposed that the crucial role of dual cocatalysts is general for photocatalysis.
Abstract
We extend the halo-based group finder developed by Yang et al. (2005c) to use data
simultaneously
with either photometric or spectroscopic redshifts. A mock galaxy redshift survey ...constructed from a high-resolution
N
-body simulation is used to evaluate the performance of this extended group finder. For galaxies with magnitude z ≤ 21 and redshift 0 <
z
≤ 1.0 in the DESI legacy imaging surveys (the Legacy Surveys), our group finder successfully identifies more than 60% of the members in about 90% of halos with mass ≳10
12.5
h
−1
M
⊙
. Detected groups with mass ≳10
12.0
h
−1
M
⊙
have a purity (the fraction of true groups) greater than 90%. The halo mass assigned to each group has an uncertainty of about 0.2 dex at the high-mass end ≳10
13.5
h
−1
M
⊙
and 0.45 dex at the low-mass end. Groups with more than 10 members have a redshift accuracy of ∼0.008. We apply this group finder to the Legacy Surveys DR8 and find 6.4 million groups with at least three members. About 500,000 of these groups have at least 10 members. The resulting catalog containing 3D coordinates, richness, halo masses, and total group luminosities is made publicly available.
Photocatalytic H2 production on MoS2/CdS photocatalysts in the presence of different sacrificial reagents under visible light (λ > 420 nm) has been investigated. The transformation process of the Mo ...species loaded on CdS, together with the junctions formed between MoS2 and CdS, was clearly demonstrated with X-ray photoelectron spectroscopy and transmission electron microscopy. Photocatalytic H2 evolution was optimized for MoS2/CdS catalysts. The 0.2 wt % MoS2/CdS catalyst calcined at 573 K achieves the highest overall activity for H2 evolution, and the 0.2 wt % MoS2/CdS catalyst demonstrates even higher activity than the 0.2 wt % Pt/CdS, irrespective of different sacrificial reagents used. The junctions formed between MoS2 and CdS play an important role in enhancing the photocatalytic activity of MoS2/CdS catalysts. Electrochemical measurements indicate that MoS2 is an excellent H2 evolution catalyst, which is another very important factor responsible for the enhancement of the photocatalytic activity of MoS2/CdS catalysts.
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