Search Results (795)

Yaks (Bos grunniens) are important livestock on the Qinghai–Tibetan Plateau, but the relationship between Blastocystis positivity, fecal bacterial communities, and microbial metabolites remains unclear. This cross-sectional study compared fecal bacterial profiles and short-chain fatty acid (SCFA) concentrations in six Blastocystis-positive and six Blastocystis-negative diarrheic yaks from Lhasa, Tibet Autonomous Region, China. Bacterial communities were characterized by 16S rRNA gene amplicon sequencing, and fecal SCFAs were quantified by gas chromatography–mass spectrometry. Compared with negative yaks, positive yaks had lower concentrations of acetic acid (p < 0.01), propionic acid (p < 0.01), butyric acid (p = 0.000381), valeric acid (p < 0.01), caproic acid (p = 0.00359), and isobutyric acid (p < 0.01), whereas isovaleric acid did not differ between groups (p = 0.310). A total of 2,751,028 raw sequences were generated, of which 2,620,949 passed quality filtering. ACE (p = 0.0068), Chao1 (p = 0.0071), Faith’s phylogenetic diversity (p = 0.0019), observed ASVs (p = 0.0064), Pielou’s evenness (p = 0.011), Shannon diversity (p = 0.008), and Simpson diversity (p = 0.037) were lower in positive yaks. The groups also differed in bacterial community composition, and several taxa previously associated with fiber degradation or SCFA formation had lower relative abundances in positive yaks. PICRUSt2 indicated differences in predicted microbial functional potential. These findings indicate that Blastocystis positivity was associated with altered fecal bacterial communities and reduced concentrations of several SCFAs in diarrheic yaks. Because of the small sample size, cross-sectional design, and potential confounding by diarrhea and other unmeasured factors, causal relationships cannot be established. Full article

Enramycin is used as a dietary antimicrobial in young animals, but its effects on rabbit colonic ecology remain insufficiently characterized. This study evaluated the effects of enramycin in 60 weaned rabbits randomly assigned to a control or enramycin-treated group (60 mg/kg) for 14 days (n = 30/group). Clinical outcomes were evaluated in all rabbits, whereas paired colonic multi-omics profiling was performed in six randomly selected survivors per group with no recorded diarrhea. Enramycin reduced diarrhea incidence without affecting body-weight development, organ indices, or mortality. Metagenomic analysis revealed unchanged alpha diversity but significant alterations in microbial community structure, including decreased Verrucomicrobiota, Akkermansia, and Alistipes and increased Cyanobacteria and Avigastranaerophilus. Untargeted metabolomics identified 332 features meeting the predefined screening criteria, including 143 upregulated and 189 downregulated metabolites. Prominent pathway annotations included phenylpropanoid biosynthesis and arachidonic acid metabolism. Resistome analysis demonstrated that treatment drove shifts in streptothricin-, aminoglycoside- and glycopeptide-related resistance signatures. The integrated analysis identified associations between four selected genera and the top 30 differential metabolites. Overall, dietary enramycin was associated with a short-term reduction in diarrhea incidence and concurrent changes in selected colonic microbial, metabolic, and resistance gene features. These findings extend enramycin evaluation beyond conventional clinical outcomes and highlight the importance of considering broader ecological effects when assessing dietary antimicrobial exposure in weaned rabbits. Full article

Species in Gentiana sect. Cruciata (Gentianaceae) are usually used as a bulk medicinal herb with multiple clinical therapeutic functions, yet wild populations have declined drastically due to overharvesting and environmental changes, prompting urgent conservation demands. This study collected occurrence records of eight sect. Cruciata species and integrated forty-two environmental variables. MaxEnt models were optimized using the “kuenm” R package v. 3.6.3 to predict their potential suitable areas under current and future climate scenarios (SSP126 and SSP585), followed by analyses of spatial pattern changes and centroid migration. Results showed that all optimized models achieved average AUC > 0.9, indicating high prediction accuracy. Elevation, annual precipitation, human footprint index, and temperature seasonality dominantly affected the species distribution, with distinct limiting factor combinations revealing interspecific niche differentiation. Based on the prediction, the eight gentian species exhibited three divergent climate response types: climate-sensitive G. macrophylla suffered severe, irreversible habitat loss with long-distance centroid migration; five stable-adaptive species (G. straminea, G. crassicaulis, G. tibetica, G. robusta, and G. siphonantha) maintained stable core ranges and partial expansion capacity; G. dahurica and G. officinalis followed a “contraction-then-recovery” trajectory. The eastern Qinghai–Tibetan Plateau, Hengduan Mountains, Qinling Mountains, and the Gansu–Qinghai–Sichuan border represented core conservation zones for the sect. Cruciata species. Highly adaptive G. crassicaulis, G. tibetica, and G. straminea were prioritized for conservation and artificial propagation. This study revealed the differentiated responses and adaptation potentials of medicinal plants of Gentiana sect. Cruciata to climate change, providing a scientific basis for precise germplasm conservation and rational cultivation layout for sustainable medicinal resource utilization. Full article

Carcass traits, which reflect growth performance and muscle development, are economically important in beef cattle, yet their genetic determinants remain poorly characterized. Both single-population Genome-wide association studies (GWAS) methods, such as BLINK, and cross-population meta-analysis approaches are widely used to identify genetic variants, yet their comparative performance in genomic prediction for complex traits in structured populations remains underexplored. Few studies have directly compared these methods in genomic prediction. To address this gap, this study aims to (i) identify positional candidate genes associated with carcass traits and (ii) evaluate the context-dependent advantages of Covariate Adjustment (CA) and meta in genomic prediction. In this study, we analyzed carcass weight (CW), live weight (LW), and dressing percentage (DP) in 279 crossbred Angus cattle genotyped with the PHR0105_Bt140K_v1.0 SNP chip. GWAS was performed on the full population using BLINK, and results from three subpopulations were combined via meta-analysis, with significance thresholds for both approaches determined by a shuffle-based method. Candidate genes located within ±10 kb of significant SNPs were associated with different carcass traits, including STRIT1, SEL1L3, NOC4L and ANK1 for DP; SNCA and DNAH5 for CW; and GYPC, GPR158, and GUCY1A1 for LW. Prediction accuracy under MAS and MABLUP showed meta slightly outperformed BLINK in MAS, while BLINK was better with covariate adjustment; after incorporating kinship in MABLUP, meta achieved higher accuracy and population partitioning was negligible. Overall, MABLUP yielded the highest accuracy (0.52–0.79) versus MAS (0.37–0.54) in all traits. These findings provide a methodological basis for selecting appropriate GWAS strategies in structured populations and highlight candidate genes. Full article

Yaks are indigenous livestock species of the Qinghai–Tibet Plateau. Due to long-term exposure to extreme environmental stressors, including high altitude, hypoxia, and low temperatures, its male reproductive system has evolved distinct adaptive strategies. Specifically, testicular weight is markedly lower than that of cattle. Nevertheless, according to reported data from different experiments, although its single ejaculate volume is lower than that of Tibetan cattle, it can still maintain comparable fresh sperm motility. These reproductive phenotypes make the yak an ideal model organism for investigating plateau adaptation and sperm energy metabolism. The present review synthesizes continuous molecular events in yak testes spanning embryonic development through senescence. It focuses on dissecting the core regulatory networks governing spermatogonial stem cell self-renewal, meiosis, and spermiogenesis. It integrates the latest advances in testicular microenvironment dynamics and epigenetic modifications. Additionally, male sterility in cattle-yak serves as a natural mutant model. Essential regulatory modules governing spermatogenesis can be inferred from its spermatogenic-arrest phenotype. Nevertheless, comparative omics analyses between yaks and cattle are confounded by seasonal variation and differing genetic backgrounds. It is therefore critical to distinguish signatures driven by genetic adaptation from those arising from environmental plasticity. Finally, this paper presents research prospects regarding how to utilize single-cell multi-omics and gene-editing technologies to deeply dissect the underlying mechanisms of plateau reproductive adaptation to provide theoretical support for improving yak fecundity and hybrid breeding. Full article

The Waliguan–Duohemao tectonic belt on the northeastern Tibetan Plateau hosts Qinghai’s highest-temperature hot springs (Zhacanggou 98 °C, Qunaihai 97 °C) and deep hot dry rock resources in the Gonghe Basin. However, the mechanisms governing hydrothermal circulation in this region remain poorly understood, limiting the assessment of its sustainable geothermal development potential. Through integrated fluid geochemistry, borehole temperature logging, and crustal thermal structure analyses, this study reveals the dual “water–heat” control exerted by the fault zone. The fault acts as a dominant pathway for deep meteoric water circulation, controlling mixing between deep hydrothermal fluids and shallow cold water, as evidenced by continuous hydrochemical and isotopic trends. Heat flow analysis indicates surface heat flow values up to 134.66 mW/m² in the Gonghe Basin (with a 78.6% crustal contribution), decreasing to 57.4% in the Guinan area. A deep intra-crustal partial melting layer provides additional heat in the Gonghe Basin, whereas the Guide and Tongren areas rely primarily on radiogenic heat generation. The systematic increase in crustal heat flow from southwest to northeast confirms the fault zone as an efficient conduit for deep thermal transport, highlighting the region’s substantial deep geothermal energy potential. To overcome the “heat without water” exploration bottleneck and promote sustainable resource development, we propose differentiated exploration strategies tailored to the structural heterogeneity of the belt: (1) in the western Gonghe Basin, prioritize heat source characterization and enhanced geothermal system (EGS) feasibility assessment; (2) in the central Guide area, employ high-resolution geophysical methods to detect water-conducting fault zones; and (3) in the eastern Tongren area, evaluate water source conditions and fault connectivity with recharge areas. These strategies collectively minimize exploration risks and support the long-term, sustainable utilization of geothermal resources in this high-altitude region. Full article

Nitrogen limitation restricts plant growth, development, and yield in crops and forage species. Although TCP transcription factors are implicated in diverse abiotic-stress responses, the functions of most TCP genes in oat remain unclear. Here, we cloned and characterized the AsTCP38 gene, which is 1215 bp long and encodes a 405-amino-acid protein. The predicted protein contains a conserved TCP domain and shares its highest sequence similarity with Arabidopsis thaliana (A. thaliana) AtTCP15. The AsTCP38 protein localized to the nucleus, and promoter analysis identified cis-elements associated with light, hormone, and stress responses. We generated AsTCP38-overexpressing A. thaliana and wheat plants and screened an oat leaf yeast cDNA library for candidate interacting proteins. In these heterologous overexpression lines, AsTCP38 overexpression was associated with greater abscisic acid (ABA) sensitivity and improved seedling growth under low-nitrogen conditions. Changes in antioxidant-enzyme activities, nitrogen-metabolism-related enzyme activities, and endogenous hormone contents were also observed. Together, these findings suggest that AsTCP38 may participate in low-nitrogen responses and provide a basis for further functional studies in oat. Direct regulatory targets and the contribution of AsTCP38 to low-nitrogen adaptation in oat remain to be established. Full article

To elucidate the recharge relationships and hydrological processes among different water bodies in the Qinghai Lake Basin, precipitation, river water, groundwater, and lake water samples were collected from April to November 2024. The hydrogen and oxygen stable isotope compositions (δ²H and δ¹⁸O) were determined to characterize their spatiotemporal variations, and the MixSIAR model was applied to quantitatively evaluate the recharge contributions among different water bodies. The results show significant differences in stable isotope compositions among the various water bodies. Overall, lake water exhibited the most enriched isotopic signatures, whereas groundwater was the most depleted and isotopically stable, while precipitation displayed the largest variability. Precipitation isotopes exhibited pronounced seasonal effects. River water showed a depletion–enrichment–depletion pattern, reflecting the important recharge contributions from wet season precipitation and frozen-soil meltwater. Groundwater exhibited relatively weak seasonal variations and a distinct smoothing effect. In contrast, the isotopic composition of lake water was jointly controlled by evaporative fractionation and multiple recharge sources, with the highest enrichment occurring in spring and gradual depletion during wet season and dry season. Spatially, significant isotopic differences were observed among rivers. Groundwater was relatively enriched in the western part of the basin and depleted in the eastern part, whereas lake water exhibited an opposite pattern, characterized by enrichment in the east and depletion in the west. The Local Meteoric Water Line (LMWL) of the Qinghai Lake Basin was defined as δ²H = 8.07δ¹⁸O + 37.48 (R² = 0.96). Both the slope and intercept were higher than those of the Global Meteoric Water Line (GMWL), indicating that locally recycled evaporated moisture played an important role in regional precipitation formation. The river water line showed characteristics similar to those of the groundwater line, suggesting strong hydraulic connectivity between river water and groundwater. In contrast, the lake water line deviated markedly from the meteoric water line, indicating significant evaporative fractionation of lake water. The MixSIAR results indicate that the contributions of river water, groundwater, and precipitation to lake water were 37.5%, 33.9%, and 28.6%, respectively. These findings reveal the complex hydrological connections and transformation processes among multiple water bodies in the Qinghai Lake Basin and provide a scientific basis for water resource management and ecological environmental protection in inland basins of the Qinghai–Tibet Plateau. Full article

Black highland barley, rich in phenolic compounds and β-glucans, is increasingly used in craft beer brewing, but the dynamic metabolic changes across its processing chain remain unclear. This study integrated GC×GC-TOF MS based flavoromics with UHPLC-QTRAP-MS based widely targeted metabolomics to track volatile and non-volatile metabolites from raw grain (K1) through germinated malt (K2) and roasted malt (K3) to finished beer (K4). A total of 256 volatile compounds and 615 non-volatile metabolites were identified. Alcohols and hydrocarbons dominated K1. Germination (K2) enriched aldehydes and reduced esters by 66%. Roasting (K3) generated Maillard reaction products, including 2,3,5-trimethylpyrazine (198.4-fold increase) and furfural (20.2-fold increase). Fermentation (K4) shifted the profile to ester dominance (40.95%), with isoamyl alcohol (ROAV = 71.59) and 2-undecanone (ROAV = 65.37) as the principal aroma contributors. Notably, 94.1% of phenolic and flavonoid compounds (168 of 184) exhibited higher abundance in finished beer than in raw grain. Their levels declined after roasting and then accumulated during fermentation. Cross-omics correlation indicated a strong association between furfural and its pentose phosphate precursor (ρ = 1.00, p < 0.001). These findings demonstrate that fermentation acts as the decisive metabolic turning point that simultaneously shapes the flavor profile and nutritional quality of black highland barley beer. The finished beer contained 250.45 mg GAE/L total phenolics and 97.91 mg RE/L total flavonoids, with ABTS and DPPH radical scavenging rates of 87.41% and 92.68%, respectively. Full article

Biological soil crusts (BSCs) are critical components of alpine sandy land ecosystems, yet how their diazotrophic communities respond to plantation type and successional stage remains largely unknown. This study examined diazotrophic community differentiation in BSCs under four sand-fixing plantations (Salix psammophila SL, Caragana korshinskii NT, Salix cheilophila WL, Populus simonii XYY) across three successional stages in an alpine sandy land. Soil properties, microbial biomass, and enzyme activities were measured, along with nifH gene sequencing (Illumina), to characterize community composition and its relationships with environmental factors along BSCs succession. The results indicate that Skermanella, Mastigocladus, and Nostoc were the dominant diazotrophic groups in the study area. The Nostoc was the dominant genus across all plantation types, with the highest average relative abundance (37.92%) recorded in moss crusts under the XYY plantations. Diazotrophic α-diversity increased with BSCs succession, and β-diversity analysis (PCoA with ANOSIM) demonstrated significant community differentiation among plantation types (variance explanation = 50.91%, R = 0.59458, p = 0.001). Spearman’s and redundancy analysis (RDA) showed that sand-fixing plantations drive the differentiation of diazotrophic communities by regulating soil physicochemical properties and microbial metabolism. Furthermore, the diazotrophic communities in moss crusts exhibited stronger environmental responsiveness than those in algae crusts. In the COG functional categories, J (translation and ribosomal biogenesis, 7.92%), E (amino acid metabolism, 10.14%), and C (energy production, 7.11%) were identified as the core foundational functions of BSCs in the study area. The relative abundances of these functional categories showed convergence. In summary, different plantations were associated with distinct diazotrophic community compositions, and these associations were largely mediated by soil environmental factors. Concurrently, BSC succession covaried with enhanced differentiation in community structure and functional traits. These patterns are consistent with a stepwise response cascade linking vegetation and soil properties to diazotrophic communities and nitrogen metabolism functions. This study provides a theoretical basis for enhancing the stability and long-term restoration of artificial ecosystems by regulating diazotrophic communities in BSCs in alpine sandy land. Full article

High-altitude rural settlements on the Qinghai–Tibet Plateau have developed through long-term adaptation to terrain, hydrology, infrastructure, and socio-cultural organization. However, quantitative evidence on how settlement morphologies are typologically structured and how contextual constraints are associated with their differentiation remains limited. Taking 20 Tibetan rural settlements in the Lhasa River valley as samples, this study develops a hierarchical morphological typology and examines its contextual associations. Spatial indicators describing boundary form, building layout, and spatial organization were constructed from remote sensing imagery, settlement mapping, and field observations. Hierarchical clustering identified a two-level typological structure, comprising two higher-order morphological branches and four detailed settlement archetypes. ANOVA and Kruskal–Wallis tests indicated significant inter-type differences in key morphological indicators, including shape index, building density, inter-building distance, building disorder, and spatial centrality. Fuzzy-set qualitative comparative analysis was then conducted at the higher-order branch level to explore how elevation, slope, river proximity, road accessibility, and religious-spatial context combine in relation to broader morphological differentiation. The results indicate that high-altitude settlement morphology is associated with multiple contextual configurations, with no single condition acting as a universal explanatory factor. Extended–loose settlements are generally linked to more open valley settings, whereas constrained organized settlements are associated with stronger terrain, accessibility, or corridor-based spatial constraints. Although the identified archetypes are specific to the Lhasa River Valley, the analytical framework provides a basis for comparative studies of rural settlements in other high-altitude and mountainous regions. The findings provide a quantitative basis for understanding the morphological diversity of Tibetan rural settlements and offer typology-based implications for rural planning, infrastructure allocation, and landscape conservation in environmentally sensitive plateau regions. Full article

Shrub encroachment in alpine grasslands alters soil biogeochemical processes, but reported soil responses remain inconsistent and conflicting among studies. We performed a systematic review and meta-analysis to evaluate ten physical and chemical alongside biological soil properties. Evaluated indicators covered soil water content (SWC) and bulk density (BD) alongside soil organic carbon (SOC) and total nitrogen (TN). They also included ammonium (NH₄⁺-N) and total phosphorus (TP) and pH alongside microbial biomass carbon (MBC) and nitrogen (MBN) and phosphorus (MBP). In total, 66 peer-reviewed articles provided 175 paired observations across four continental alpine regions, with most studies conducted in High Mountain Asia. Most compiled studies evaluated topsoil chemical properties, while non-nitrogen-fixing shrubs dominated the dataset. Shrub encroachment significantly stimulated MBC (+7.59%) and MBN (+5.44%) across both functional groups. TN increased significantly (+2.08%) driven entirely by nitrogen-fixing shrubs (+7.57%). Nitrogen-fixing shrubs also induced rhizosphere acidification (−1.87%) and increased MBP (+14.41%). Non-nitrogen-fixing shrubs significantly reduced BD (−5.67%), while bulk SOC (+0.15%) and TP (−0.31%) showed no pooled change. SOC responses diverged sharply at the genus level, increasing under Dasiphora (+6.58%) but declining under Salix (−6.88%) and Vaccinium (−11.62%). Soil sampling depth and shrub genus identity exerted primary controls on soil carbon and nitrogen dynamics. Current evidence concentrates heavily on Qinghai–Tibetan Plateau topsoils, leaving critical geographic and subsoil data gaps across global cold alpine biomes. Given functional divergence and depth stratification, sustainable alpine management must adopt shrub regulation differentiated by functional traits, linking microscale microbial processes with whole ecosystem carbon and nitrogen cycling. Full article

This study characterized regional variation in faba bean rhizosphere bacterial communities across a broad survey of the Qinghai Plateau and examined their associations with soil and spatial factors. Rhizosphere soil samples were collected from 15 faba bean-growing field sites across Haidong City, Xining City, and Hainan Tibetan Autonomous Prefecture, Qinghai Province, China, spanning elevations from 1842.9 to 3206.3 m. Nine within-site subsamples were collected at each field site, with the field site treated as the independent unit of replication. Soil physicochemical properties were measured, and bacterial communities were characterized by high-throughput sequencing of the 16S rRNA gene. At the site level, bacterial alpha-diversity indices showed numerical variation among the three regional elevation groups, but did not differ significantly. Bacterial community composition differed among groups in the site-level PERMANOVA based on Bray–Curtis dissimilarities (pseudo-F_2.12 = 1.789, R² = 0.230, p = 0.031), although substantial overlap among sites remained. However, a conservative locality-level sensitivity analysis was not significant (p = 0.060). Geographic distance was significantly associated with bacterial community dissimilarity, whereas elevation difference showed no detectable independent association after controlling for geographic distance, indicating a substantial contribution of spatial structure to the observed community differentiation. Dominant phylum-level composition was broadly conserved across sites, while genus-level relative abundances showed descriptive spatial variation. Neither RAVD-based compositional consistency nor community-level niche breadth differed significantly among groups. Among the measured soil properties, only pH differed significantly, whereas most nutrient variables did not. Overall, the study revealed spatially structured regional differentiation in faba bean rhizosphere bacterial communities across the Qinghai Plateau. The observed patterns likely reflect the combined influence of geographic structure, elevation, background soil conditions, agricultural management, plant phenology, and other unmeasured environmental factors, which could not be independently disentangled in the present survey. Full article

Lightning discharges over the Tibetan Plateau are monitored by ground-based networks that locate radiation sources from their low-frequency radio emissions. This study uses the Qinghai Datong network in the northeastern Tibetan Plateau, which records the 50 kHz to 2.5 MHz band over a small area to locate lightning in three dimensions. In such networks, the accuracy of three-dimensional location depends critically on the consistency of the signals recorded across stations, which is progressively degraded by aging analog front-ends and by complex electromagnetic noise. To address this, we propose a phase-preserving denoising scheme, termed WZ, that suppresses both broadband and narrowband noise while keeping the relative timing between stations essentially unchanged, so that the arrival times used for location are preserved. The improvement is illustrated with both simulations and real data. In Monte Carlo simulations, WZ improves the signal-to-noise ratio by 10 dB and reduces the time-of-arrival error to 0.3 μs. Applied to two intracloud flashes of contrasting morphology, WZ recovers substantially more radiation sources and more continuous discharge channels than conventional filtering, at no cost to fit quality, allowing, for example, the downward development of the channel to be tracked quantitatively. The method requires no change to the existing hardware and can be applied to archived data, making it a practical way to improve both current and historical records from long-running low-frequency lightning networks. Full article

As a globally climate-sensitive region and ecological security barrier, the spatiotemporal dynamics of net ecosystem productivity (NEP) on the Qinghai–Tibetan Plateau are of great significance for understanding carbon cycling in alpine ecosystems. However, due to insufficient representation of parameter heterogeneity in models and unclear nonlinear attribution of complex environmental factors, substantial uncertainties remain in the spatiotemporal patterns and driving mechanisms of NEP in this region. Therefore, this study first employed an improved Carnegie–Ames–Stanford Approach (CASA) model to assess NEP on the Qinghai–Tibetan Plateau from 2000 to 2022 and characterize its spatiotemporal evolution, and subsequently applied the optimal multivariate-stratification geographical detector (OMGD) to quantify the independent and synergistic driving effects of hydrothermal conditions, extreme climate events, and human activities on NEP variations. The results indicate that: (1) from 2000 to 2022, vegetation NEP on the Qinghai–Tibetan Plateau exhibited a southeast-to-northwest decreasing spatial heterogeneity pattern, with a multi-year mean value of 219.61 g C·m⁻²; (2) during the study period, NEP showed an overall increasing trend (at a rate of 1.596 g C·m⁻²·yr⁻¹), with 52.5% of the region experiencing significant increases, primarily concentrated in the central–eastern humid regions and alpine meadow areas; and (3) among individual factors, the growing season length was the primary driver of NEP, in addition to temperature and precipitation, while human activities exerted negligible influence; under interaction effects, the hydrothermal synergistic enhancement (0.79 < q < 0.89) exhibited the highest explanatory power. These results show that carbon sequestration in alpine ecosystems is governed by nonlinear hydrothermal interactions and provide a scientific basis for assessing carbon sink resilience in the “Asian Water Tower” under global warming. Full article