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1.
Zhonghua Yan Ke Za Zhi ; 57(10): 772-776, 2021 Oct 11.
Artigo em Chinês | MEDLINE | ID: mdl-34619948

RESUMO

Objective: To investigate the influencing factors of refractive status of preschool children in Changdu, Tibet. Methods: From July 2020 to October 2020, a cross-section investigation was performed among preschool children in Changdu, Tibet. The general information was collected, and the uncorrected refractive status was recorded and investigated. The measurement data were expressed by mean±standard deviation, and the t-test and χ2 test were used for univariate analysis. The questionnaire of factors influencing children's visual acuity was distributed to the parents of the children. The independent variables included height, weight, nutritional status, parents' eyesight, sleeping time and habits that were bad for eyes. Multivariate logistic regression analysis was used to explore the influencing factors of refractive status, including age and gender. Results: A total of 2 793 children were screened, among whom 2 646 (98.64%) children including 1 501 males and 1 145 females were inhabitants in the plateau region. The average age was (4.52±0.97) years. Refractive abnormalities were found in 253 children (9.56%). The detection rate of refractive abnormalities increased with age. There was no significant difference between males and females (χ²=1.79, P>0.05). The total abnormal refraction rate of preschoolers was lower in the plateau region than the non-plateau region (χ²=13.93, P<0.05). The parental refractive status (OR=0.06, 95%CI: 0.04-0.08) and nutritional factors (OR=0.11, 95%CI: 0.04-0.25) had higher correlations with the refractive abnormalities of preschoolers. Conclusions: The rate of refractive abnormalities of preschool children was relatively low in Changdu, Tibet. One of the effective measures to prevent ametropia in the plateau area can be balanced nutrition. (Chin J Ophthalmol, 2021, 57: 772-776).


Assuntos
Erros de Refração , Pré-Escolar , Feminino , Humanos , Masculino , Pais , Erros de Refração/epidemiologia , Inquéritos e Questionários , Tibet , Acuidade Visual
2.
Ying Yong Sheng Tai Xue Bao ; 32(9): 3119-3126, 2021 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-34658196

RESUMO

A field manipulative experiment was carried out during 2015 and 2016 to examine the changes and influencing factors of root production, turnover rate, and standing crop under different nitrogen (N) addition levels, i.e., 0, 1, 2, 4, 8 and 16 g N·m-2·a-1, in a Tibetan alpine steppe. The results showed that root production and standing crop decreased linearly or exponentially with increasing N addition rates. Compared with control, 16 g N·m-2·a-1 significantly reduced the two-year average root production and standing crop by 43.0% and 45.7%, respectively. Root turnover rate increased first and then decreased along the N addition gradient, with the maximum appearing under 2 and 4 g N·m-2·a-1 treatments for 2015 and 2016, respectively. Results from linear mixed-effects models showed that root starch content was the main factor modulating the N-induced changes in root production and turnover rate, explaining 21.7% and 25.4% of their variations. Root protein content mainly contributed to the variations in standing crop, with an explanation of 20.8% of its variance. Overall, N addition had negative effect on root production and standing crop, and low N promoted while high N inhibited root turnover rate. Root metabolic parameters were the main factors modulating the N-induced changes in root dynamics.


Assuntos
Nitrogênio , Raízes de Plantas , China , Tibet
3.
Zhongguo Zhong Yao Za Zhi ; 46(18): 4765-4773, 2021 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-34581087

RESUMO

In this study, data of amino acids of Cordyceps samples from Qinghai and Tibet was analyzed with self-organizing map neural network. A model of XY-Fused network was established with the content of 8 major amino acids and total amino acids for the identification of geographical origins of Cordyceps from Qinghai and Tibet. It had the prediction accuracy of 83.3% for the test set. In addition, data mining indicated that methionine was a special kind of amino acid in Cordyceps which could serve as a marker to identify its geographical origins. On this basis, the content ratio of methionine to total amino acids was proposed to be a quantifiable indicator to distinguish Cordyceps from Qinghai and Tibet.


Assuntos
Cordyceps , Aminoácidos , Cordyceps/genética , Geografia , Redes Neurais de Computação , Tibet
4.
Huan Jing Ke Xue ; 42(10): 4959-4967, 2021 Oct 08.
Artigo em Chinês | MEDLINE | ID: mdl-34581140

RESUMO

Denitrification is a key process in the nitrogen cycle of ecosystems. Most existing studies of nitrogen emissions and denitrifying bacterial communities are carried out in ecosystems with significant human interference, yet few focus in natural ecosystems with low human disturbance. Here, the denitrification rates and characteristics of nirS-type denitrifying bacterial communities in rhizosphere and bulk soils from alpine wetland plants at different altitudes(Tangke, Jiuzhi, Maduo, and Dari) and seasons(spring and summer) in the Yellow River source region of the Qinghai-Tibet Plateau were investigated. The 15N isotope tracer technique was used to estimate the denitrification rates, and high-throughput sequencing technology was used to determine the composition and relative abundance of nirS-type denitrifying bacterial communities. We also investigated the environmental factors(temperature and altitude) and soil physical and chemical properties(pH, soil organic carbon, ammonia, nitrate, and nitrite) controlling the denitrification and related microorganisms. The results show that the denitrification rates of alpine wetland soils ranged from 0.80 to 14.98 nmol·(g·h)-1, and the contribution to the total N2 production ranged from 11.23% to 71.16%. The soil samples from Tangke, Jiuzhi, and Dari showed higher denitrification rates in rhizosphere soils than the corresponding bulk soils(P<0.05). Proteobacteria was the most dominate denitrifying bacteria phylum. At the genus level, unclassified Proteobacteria(2.86%-29.41%) showed the highest relative abundance, indicating that unique unidentified bacteria may dominate denitrification in these wetland soils. The genera with the next highest relative abundances were Pseudomonas(2.45%-26.52%) and Cupriavidus(0%-34.14%). Distance-based redundancy analysis showed that the community structure of the nirS-type denitrifying bacteria was mainly affected by altitude, pH, and nitrite concentrations; Pearson correlation analysis showed that denitrification rates and the Shannon index are significantly negatively correlated with soil pH(P<0.05), and the relative abundance of the main denitrifying bacterial genera were influenced by temperature and soil pH(P<0.05). This study provides valuable insights for understanding the nitrogen cycle in the unique alpine wetlands of the Qinghai-Tibet Plateau.


Assuntos
Solo , Áreas Alagadas , Bactérias/genética , Carbono , Desnitrificação , Ecossistema , Humanos , Rizosfera , Estações do Ano , Microbiologia do Solo , Tibet
5.
Environ Sci Technol ; 55(18): 12261-12271, 2021 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-34469681

RESUMO

Formation pathways and sources of atmosphere nitrate (NO3-) have attracted much attention as NO3- had detrimental effects on Earth's ecosystem and climate change. Here, we measured nitrogen (δ15N-NO3-) and oxygen (δ18O-NO3- and Δ17O-NO3-) isotope compositions in nitrate aerosols at the Qomolangma station (QOMS) over the Himalayan-Tibetan Plateau (HTP) to quantify the formation mechanisms and emission sources of nitrate at the background site. At QOMS, the enhanced NO3- concentrations were observed in the springtime. The average δ15N-NO3-, δ18O-NO3-, and Δ17O-NO3- values were 0.4 ± 4.9, 64.7 ± 11.5 and 27.6 ± 6.9‰, respectively. Seasonal variations of isotope ratios at QOMS can be explained by the different emissions and formation pathways to nitrate. The average fractions of NO2 + OH and N2O5 + H2O to nitrate production were estimated to be 43 and 52%, respectively, when the NO3 + hydrocarbon (HC)/dimethyl sulfide (DMS) (NO3 + HC/DMS) pathway was assumed to be 5%. Using stable isotope analysis in the R (SIAR) model, the relative contributions of biomass burning (BB), biogenic soil emission, traffic, and coal combustion to nitrate were estimated to be 28, 25, 24, and 23%, respectively, on yearly basis. By FLEXible PARTicle (FLEXPART) dispersion model, we highlighted that NOx from BB emission over South Asia that had undergone N2O5 + H2O processes enhanced the nitrate concentrations in the springtime over the HTP region.


Assuntos
Nitratos , Nitrogênio , Aerossóis , China , Ecossistema , Monitoramento Ambiental , Nitratos/análise , Nitrogênio/análise , Isótopos de Nitrogênio/análise , Isótopos de Oxigênio/análise , Tibet
6.
Front Cell Infect Microbiol ; 11: 713873, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34552884

RESUMO

Cryptosporidium is an enteric apicomplexan parasite, which can infect multiple mammals including livestock and wildlife. Tibetan Antelope (Pantholops hodgsonii) is one of the most famous wildlife species, that belongs to the first class protected wild animals in China. However, it has not been known whether Tibetan Antelope is infected with Cryptosporidium so far. The objective of the present study was to determine the prevalence and characterization of Cryptosporidium species infection in Tibetan Antelope and the corresponding species by using molecular biological method. In the current study, a total of 627 fecal samples were randomly collected from Tibetan Antelope in the Tibet Autonomous Region (2019-2020), and were examined by PCR amplification of the small subunit ribosomal RNA (SSU rRNA) gene. Among 627 samples, 19 (3.03%, 19/627) were examined as Cryptosporidium-positive, with 7 (2.33%, 7/300) in females and 12 (3.67%, 12/327) in males. The analysis of SSU rRNA gene sequence suggested that only two Cryptosporidium species, namely, C. xiaoi and C. ubiquitum, were identified in this study. This is the first evidence for an existence of Cryptosporidium in Tibetan Antelope. These findings extend the host range for Cryptosporidium spp. and also provide important data support for prevention and control of Cryptosporidium infection in Tibetan Antelope.


Assuntos
Antílopes , Criptosporidiose , Cryptosporidium , Animais , China/epidemiologia , Criptosporidiose/epidemiologia , Cryptosporidium/genética , Fezes , Feminino , Masculino , Filogenia , Prevalência , Tibet
7.
J Environ Manage ; 300: 113740, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34530362

RESUMO

Water resources in good quality guarantee the primary condition for the maintenance and development of the natural ecosystem and human society. Water quality status and health risk of the lake water bodies in the national nature reserve, the Yamdrok-tso basin, in the southern Tibetan Plateau are assessed by 25 water parameters including 12 heavy metal(loid)s. Results reveal that the lake water bodies possess relatively high pH (9.68), high concentrations of F (1.66 mg/L), Cu (13.92 µg/L), As (41.60 µg/L), Pb (26.69 µg/L), and U (19.53 µg/L), and a low value of dissolved oxygen (19.30%). The pollution indices (heavy metal pollution index of 0.88-22.88, heavy metal evaluation index of 0.18-3.75, and the degree of contamination of -8.82 to -5.25) demonstrate that the lake water bodies are in a low pollution level with respect to heavy metal(loid)s. The evaluation of water quality based on the fuzzy comprehensive assessment method suggests that 75.56% of the water samples meet the regulation of the China National Standard for water resources in national nature reserves. Health risk assessment shows that potential hazards exist on this region when the residents under long-term exposure to the lake water through oral and dermal pathways, of which children and adults are mostly exposed to As and F for non-carcinogenic and As for carcinogenic risks, especially for children. Results of this study contribute to targeted water resources management in the national nature reserves.


Assuntos
Metais Pesados , Poluentes Químicos da Água , Adulto , Criança , China , Ecossistema , Monitoramento Ambiental , Humanos , Metais Pesados/análise , Medição de Risco , Tibet , Poluentes Químicos da Água/análise , Qualidade da Água
8.
Int J Chron Obstruct Pulmon Dis ; 16: 2445-2454, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34483657

RESUMO

Background: COPD at high altitude may have different risk factors and unique clinical and radiological phenotypes. We aimed to investigate the demographic data, clinical and radiological features of COPD patients permanently residing at the Tibet Plateau (≥3000 meters above sea level). Methods: We conducted an observational cross-sectional study which consecutively enrolled COPD patients visiting the outpatient of Respiratory Medicine at Tibet Autonomous Region People's Hospital from January 2018 to March 2021. All patients were Tibetan permanent residents aging ≥40 years and met the diagnosis of COPD according to Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines. Data including demographic characteristics, altitude of residence, risk factors, respiratory symptoms, comorbidities and medications, as well as computed tomography (CT) measurements were collected. Results: Eighty-four patients with definite COPD were enrolled for analysis. Their mean age was 64.7 (±9.1) years. All patients lived at ≥3000 m above sea level and 34.5% of them lived at ≥4000 m. About 8.3% of the patients were current smokers and 44.0% were ex-smokers. Up to 88.1% of the patients reported long-term exposure to indoor biomass fuels. Most of the patients were classified as having mild-to-moderate (GOLD I: 27.4%; GOLD II: 51.2%) COPD, while 89.3% had a CAT score ≥10. Only 36.9% of the patients received regular long-term medications for COPD in the past year, in whom ICS/LABA and oral theophylline were the most common used pharmacological therapy. On CT scanning, the majority of our patients (70.7%) showed no or minimal emphysema, while signs of previous tuberculosis were found in 45.1% of the patients. Conclusion: COPD patients living at the Tibet Plateau had a heavy respiratory symptom burden, but most of them did not receive adequate pharmacological treatment. Indoor biomass fuel exposure and previous tuberculosis were prevalent, while the emphysema phenotype was less common in this population.


Assuntos
Doença Pulmonar Obstrutiva Crônica , Enfisema Pulmonar , Estudos Transversais , Humanos , Doença Pulmonar Obstrutiva Crônica/diagnóstico por imagem , Doença Pulmonar Obstrutiva Crônica/epidemiologia , Tibet
9.
BMJ Open ; 11(9): e052207, 2021 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-34489294

RESUMO

OBJECTIVES: To explore the prevalence, awareness, treatment and control rate of hypertension and analyse the potential social environment factors among Ngawa Tibetans in China. DESIGN: This was a cross-sectional observational study. SETTING: The investigation based on a multistage stratified cluster sampling was conducted in the Ngawa area, Sichuan Province, Southwest China. Tibetan residents were selected by random sampling method from one city and six counties in Ngawa. METHODS: Basic demographical information, physical activity and blood pressure were collected. In addition, the participants completed the questionnaire. A multivariate logistic regression analysis was used to examine the association between the prevalence, awareness, treatment and control rate of hypertension and the potential risk factors. PARTICIPANTS: The sample comprised 2228 Ngawa Tibetan residents (age 18-80 years) from September 2018 to June 2019. RESULTS: The prevalence rate of hypertension was 24.6%. The control rate was 6.2%, while the awareness rate (32.3%) and treatment rate (21.7%) of hypertension had been significantly improved. CONCLUSION: The prevalence of hypertension among Ngawa Tibetans was high. The awareness and treatment were improved in recent years. But the control rate was low. The government needs to strengthen the basic medical care and health education for Ngawa Tibetans.


Assuntos
Hipertensão , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , China/epidemiologia , Estudos Transversais , Humanos , Hipertensão/epidemiologia , Pessoa de Meia-Idade , Prevalência , Tibet , Adulto Jovem
10.
Environ Sci Technol ; 55(19): 12951-12960, 2021 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-34524792

RESUMO

Plastic pollution is fast becoming one of the most pressing global issues that we currently face. Remote areas, such as the polar regions and the Tibetan Plateau, are now also exposed to microplastic contamination. However, with the impact of global warming, the transport of microplastics within the glacier-lake basins in such regions remains unclear. In this work, the Nam Co Basin in the Tibetan Plateau was selected to study the characteristics of microplastics in the rain fallout, lake water, glacial runoff, and non-glacial runoff. Fiber and films were the most common microplastic morphologies in all water samples; a higher proportion (37%) of light-weighing polypropylene and small-size (50-300 µm, ∼30%) microplastics were found in the glacial runoff. Air mass trajectory analysis showed that microplastics could be transported through the atmosphere over a distance of up to 800 km. For microplastic loading in lakes, the atmospheric fallout was estimated to be 3.3 tons during the monsoon season, whereas the contributions of glacial runoff (∼41 kg) and non-glacial runoff (∼522 kg) were relatively low. For the microplastic loading in glaciers, the atmospheric deposition was ∼500 kg/yr, and the output caused by glacial melting only accounted 8% of the total atmospheric input. All these results suggested that the dominant pathway through which microplastics enter remote mountainous lake basins is atmospheric deposition, and once deposited on glaciers, microplastics will be stored for a long time. This work provides quantitative evidence elucidating the fate of microplastics in alpine lake environments.


Assuntos
Microplásticos , Poluentes Químicos da Água , Monitoramento Ambiental , Lagos , Plásticos , Tibet , Poluentes Químicos da Água/análise
11.
Sci Total Environ ; 792: 148363, 2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34465051

RESUMO

The alpine meadow in the Qinghai-Tibet Plateau has been seriously degraded due to human activities and climate change in recent decades. Understanding the changes of the soil microbial community in response to the degradation process helps reveal the mechanism underlying the degradation process of alpine meadows. We surveyed and analyzed changes of the vegetation, soil physicochemical properties, and soil microbial community in three degradation levels, namely, non-degradation (ND), moderate degradation (MD), and severe degradation (SD), of the alpine meadows in the northeastern Qinghai-Tibet Plateau. We found that as the level of degradation increased, plant cover, plant density (PD), above-ground biomass (AGB), plant Shannon-Wiener index (PS), soil water content (SWC), soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), total potassium (TK), available nitrogen (AN), available phosphorus (AP), and available potassium (AK) decreased significantly, while the soil pH increased from 7.20 to 8.57. Alpine meadow degradation significantly changed the composition of soil bacterial and fungal communities but had no significant impact on the diversity of the microbial communities. Functional predictions indicated that meadow degradation increased the relative abundances of aerobic_chemoheterotrophy, undefined_saprotroph, and plant_pathogen, likely increasing the risk of plant diseases. Redundancy analysis revealed that in ND, the soil microbial community was mainly regulated by PS, PH, PD, SWC, and soil pH. In MD, the soil microbial community was regulated by the soil's available nutrients and SOC. In SD, the soil microbial community was not only regulated by the soil's available nutrients but also influenced by plant characteristics. These results indicate that during alpine meadow degradation, while the changes in the plants and soil environmental factors both affect the composition of the soil microbial community, the influence of soil factors is greater. The soil's available nutrients are the main driving factors regulating the change in the soil microbial community's composition alongside degradation levels.


Assuntos
Microbiota , Solo , Carbono/análise , Pradaria , Humanos , Nutrientes , Microbiologia do Solo , Tibet
12.
Braz J Biol ; 83: e245862, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34495148

RESUMO

Except for a few stick insects that are economically valuable, most species be considered to be forest pests, so it is extremely important to obtain plant host-use information of more stick insects. In this paper, the plant hosts of three species of stick insects were recorded for the first time. We also discovered these stick insects can feed upon the flowers or leaves of plants. Lopaphus unidentatus (Chen & He, 1995) (Phasmida: Lonchodidae) attacked Hypericum choisianum Wall. ex N. Robson, 1973 (Hypericaceae), Leurophasma dolichocercum Bi, 1995 (Phasmida: Aschiphasmatidae) attacked Antenoron filiforme (Thunb.) Roberty & Vautier, 1964 (Polygonaceae) and Megalophasma granulatum Bi, 1995 (Phasmida: Lonchodidae) attacked Debregeasia orientalis C. J. Chen, 1991 (Urticaceae). Finally, we were lucky enough to also obtain photographs of them mating and feeding.


Assuntos
Insetos , Plantas , Animais , Flores , Folhas de Planta , Tibet
13.
Chemosphere ; 282: 131105, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34470159

RESUMO

Atmospheric wet deposition is an important process for the occurrence of perfluoroalkyl substances (PFASs) in polar/remote mountain regions; however, there are limited data on PFASs in precipitation from the Tibetan Plateau (TP). Precipitation (rain from May to October 2017) was therefore collected across the TP to investigate the concentrations, composition profiles, sources, and fluxes of perfluoroalkyl acids (PFAAs). The average ∑PFAA concentrations ranged from 212.3 pg L-1 to 547.7 pg L-1, and perfluoroalkyl carboxylic acids (PFCAs) accounted for 87% of the measured PFAAs (mean value). Significant positive associations (p < 0.05) were found for most PFCAs in the southeast TP, indicating that they may come from similar sources. The monthly PFAA deposition flux ranged from 12.6 to 68.9 ng m-2 month-1, decreasing from east to west. As climate of the eastern TP is controlled mainly by the Indian monsoon, indicating that the Indian monsoon plays an important role in delivering PFAAs to the TP. PCA (principal component analysis) combined with back-trajectory analysis was used to estimate the atmospheric transport pathways, and the PSCF (potential source contribution function) model was applied to define the potential source regions of individual PFAAs. The results suggested that northeast India, Bangladesh, and southern Nepal are the potential sources of C4-C7 PFCAs; C8-C10 PFCAs are more influenced by emissions from southern Nepal and Bhutan; while the source regions of long-chain PFCAs (C11-C12) can be attributed to northern India and Pakistan. Specifically, PFOS (perfluorooctane sulfonic acid) has a local contribution from the central TP.


Assuntos
Ácidos Alcanossulfônicos , Fluorcarbonetos , Poluentes Químicos da Água , Ácidos Alcanossulfônicos/análise , Monitoramento Ambiental , Fluorcarbonetos/análise , Estações do Ano , Tibet , Poluentes Químicos da Água/análise
14.
Sci Total Environ ; 798: 149211, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34375235

RESUMO

Climate warming has been proposed to increase primary production of natural grasslands in cold regions. However, how climate warming affects the production of artificial pastures in cold regions remains unknown. To address this question, we used open-top chambers to simulate warming in a major artificial pasture (forage oat) on the cold Tibetan Plateau for three consecutive years. Surprisingly, climate warming decreased aboveground and belowground biomass production by 23.1%-44.8% and 35.0%-46.5%, respectively, without a significant impact on their ratio. The adverse effects on biomass production could be attributed to the adverse effects of high-temperatures on leaf photosynthesis through increases in water vapor pressure deficit (by 0.05-0.10 kPa), damages to the leaf oxidant system, as indicated by a 46.6% increase in leaf malondialdehyde content, as well as reductions in growth duration (by 4.7-6.7 days). The adverse effects were also related to exacerbated phosphorus limitation, as indicated by decreases in soil available phosphorus and plant phosphorus concentrations by 31.9%-40.7% and 14.3%-49.4%, respectively, and increases in the plant nitrogen: phosphorus ratio by 19.2%-108.3%. The decrease in soil available phosphorus concentration could be attributed to reductions in soil phosphatase activities (by 9.6%-18.5%). The findings of this study suggest an urgent need to advance agronomic techniques and cultivate more resilient forage genotypes to meet the increasing demand of forage for feeding livestock and to reduce grazing damage to natural grasslands on the warming-sensitive Tibetan Plateau.


Assuntos
Plantas , Solo , Biomassa , Pradaria , Fotossíntese , Tibet
15.
Sci Total Environ ; 798: 149362, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34375268

RESUMO

The alpine meadow ecosystem, as the main ecosystem of the Qinghai-Tibet Plateau, has been heavily degraded over the past several decades due to overgrazing and climate change. Although soil microorganisms play key roles in the stability and succession of grassland ecosystems, their response to grassland degradation has not been investigated at spatial scale. Here, we systematically analyzed the spatial turnover rates of soil prokaryotic and fungal communities in degraded and undegraded meadows through distance-decay relationship (DDR) and species area relationship (SAR), as well as the community assembly mechanisms behind them. Although the composition and structure of both fungal and prokaryotic communities showed significant changes between undegraded and degraded meadows, steeper spatial turnover rates were only observed in fungi (Degraded Alpine Meadow ß = 0.0142, Undegraded Alpine Meadow ß = 0.0077, P < 0.05). Mantel tests indicated that edaphic variables and vegetation factors showed significant correlations to the ß diversity of fungal community only in degraded meadow, suggesting soil and vegetation heterogeneity both contributed to the variation of fungal community in that system. Correspondingly, a novel phylogenetic null model analysis demonstrated that environmental selection was enhanced in the fungal community assembly process during meadow degradation. Interestingly, dispersal limitation was also enhanced for the fungal community in the degraded meadow, and its relative contribution to other assembly process (i.e. selection and drift) showed a significant linear increase with spatial distance, suggesting that dispersal limitation played a greater role as distance increased. Our findings indicated the spatial scaling of the fungal community is altered during meadow degradation by both niche selection and dispersal limitation. This study provides a new perspective for the assessment of soil microbial responses to vegetation changes in alpine areas.


Assuntos
Pradaria , Micobioma , Ecossistema , Filogenia , Solo , Microbiologia do Solo , Tibet
16.
Sci Total Environ ; 800: 149572, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34392221

RESUMO

The replacement of dominant sedges/grasses with secondary forbs is common in alpine rangelands, but the underlying plant ecological strategies and their relevance to leaf traits and their variabilities of different plant functional groups remain largely unknown. Here, we measured key leaf traits and analyzed the competitor, stress-tolerator and ruderal (CSR) strategies of major species with different functional groups (sedges, grasses and forbs) in an alpine meadow along a degradation gradient on the Tibetan Plateau. Our results indicated that S-selected species were dominant in both non-degraded (C:S:R = 1:95:4%) and severely degraded (C:S:R = 2:87:11%) meadows. However, there was a shift from S- to R-strategy in the communities after rangeland degradation. More specifically, sedges and grasses with a "conservative" strategy maintained stronger S-strategy to tolerate degraded and stressful conditions. In contrast, forbs with an "opportunistic" strategy (increase 9.5% in R-score) tended to adapt to degraded stages. Moreover, 51.1% and 23.9% of the increased R-scores in forbs were accounted by leaf mass per area and specific leaf area, respectively. Generally, higher leaf water and nitrogen contents coupled with larger variations in leaf traits and flexible SR strategies in forbs enabled them to capitalize on lower soil water and nutrient availability. Our findings highlighted that the contrasting strategies of plant species in response to the decrease in available resources might lead to niche expansion of secondary forbs and loss of diversity in the degraded alpine meadow. The emerging alternative stable states in the degraded rangelands might bring about a predicament for rangeland restoration.


Assuntos
Pradaria , Plantas , Biomassa , Solo , Tibet
17.
J Clin Hypertens (Greenwich) ; 23(9): 1802-1809, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34418250

RESUMO

This study aimed to investigate the hypertension management abilities of rural physicians in a high-altitude Tibetan area. A cross-sectional survey was conducted in the Ganzi Tibetan Autonomous Prefecture, China, in October 2020. Information about healthcare resources in local medical institutions, along with the knowledge, attitudes, practices, and training status of primary care physicians, was collected. Limited resources were observed in terms of equipment, drugs, and personnel in the 18 township hospitals included. A total of 132 physicians participated in this survey. The scores for hypertension-related knowledge, attitudes toward hypertension management, routine practice ability, priority given to hypertension, and confidence in performing certain tasks were 32.60%, 67.40%, 18.90%, 65.15%, and 35.60%, respectively. The most concerning issues lay in the ignorance of the healthy lifestyle, undervaluation of cardiovascular risks, and lack of confidence in optimally performing management activities. Only 9.85% of the physicians received more than 24 days of training per year; 28.79% preferred a longer training time. While training was generally provided in conference sessions (63.64% of current training programs), physicians preferred remote education (55.30%), and on-site guidance (46.21%) from professionals. The current training was centered around clinical skills (61.36%) and was identified as a major training requirement by the physicians surveyed (80.30%). This survey suggests that the medical resources may not be effective, with deficiencies present in the knowledge and practices of primary care physicians in the Sichuan Tibetan area. Hypertension education and skill-development courses based on the specific issues identified should be provided to these physicians in the future.


Assuntos
Hipertensão , Médicos de Atenção Primária , China/epidemiologia , Estudos Transversais , Humanos , Hipertensão/diagnóstico , Hipertensão/tratamento farmacológico , Hipertensão/epidemiologia , Tibet
18.
Gene ; 803: 145893, 2021 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-34384864

RESUMO

Glycolysis and heat shock proteins (HSPs) play an important role in mediating the physiological response to hypoxia. The changes of glycolysis and HSPs with altitude would provide important information regarding ways to prevent hypoxia-related sickness in both animals and humans. In this study, the expression pattern of HIF1A, PDK4, HSP27 and HSP60, indexes activity and content of glucose metabolism were detected in heart, lung, brain, and quadriceps femoris taken from Tibetan sheep (Ovis aries) that were raised at different altitudes (2,500 m, 3,500 m and 4,500 m). The expression of HIF1A and PDK4 was increased with increasing altitude in all of the tissues. The lactate dehydrogenase (LDH) activities and adenosine triphosphate (ATP), nicotinamide adenine dinucleotide (NADH (redox state), NAD+), lactic acid (LA), pyruvic acid (PA) contents were all increased with increasing altitude in all of the tissues. The ratio of NADH/NAD+ and LA/PA were higher in sheep at an altitude of 4,500 m than of 3,500 m and 2,500 m in all tissues, except for the NADH/NAD+ ratio in lung and quadriceps femoris. An increase in the protein and mRNA expression of ATP-independent HSP27 during hypoxia condition was detected. The expression of ATP-dependent HSP60 mRNA and protein was increased in all of the tissues at an altitude of 3,500 m than of 2,500 m, but was decreased at an altitude of 4,500 m. These results suggest that glycolysis and HSPs are upregulated to ensure energy supply and proteostasis during hypoxia, but energy conservation may be prioritized over cytoprotective protein chaperoning in Tibetan sheep tissues during extreme hypoxia.


Assuntos
Aclimatação , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Altitude , Animais , Hipóxia Celular , Regulação da Expressão Gênica , Glicólise , Ovinos , Tibet , Regulação para Cima
19.
Nutrients ; 13(7)2021 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-34371952

RESUMO

The distinct Tibetan regional diet is strongly influenced by the regional biogeography, indigenous traditions, popular religious beliefs and food taboos. In the context of the nutritional transition in Tibet, studies seldom report on the food consumption and dietary patterns of Tibetan residents. This is a cross-section study of 552 local adults (≥18 years old, 277 men and 275 women) living in 14 agricultural countries along the Yarlung Tsangpo River. Dietary intakes were assessed by a culturally specific FFQ and compared with the Chinese Dietary Pagoda (2016). Dietary Patterns were extracted by using PCA method. The binary logistic regression model was applied to assess the association between independent variables (genders, regions and age groups) and adherence to dietary patterns. With the exception of meat (100 ± 260 g/day) and soybean nuts (42 ± 12 g/day), which exceeded the recommended dietary intakes of CDP, the dietary intake of other foods were not up to the recommended value. In particular, the intake of aquatic products (2 ± 0.1 g/day), vegetables (90 ± 19 g/day), dairy products (114 ± 29 g/day), cereals (117 ± 27 g/day) and fruits (97 ± 25 g/day) were seriously inadequate, which were 95%, 70%, 62%, 53.2% and 51.5% lower than the recommended intakes, respectively. Four dietary patterns were identified. "Local traditional diet" was characterized by a high intake of tsampa (roasted highland barley flour), culturally specific beverages (sweet tea and yak buttered tea), potato and yak beef and was associated with female, rural and older adults (≥51 years old). The male, urban and 18~30 years old group had a higher adherence score with the "Han diet", which was comprised of rice, pork, dumplings, eggs, milk and cabbage. The "Beverage diet", which mainly include tsampa, chang (homemade barley wine) and sweet tea, was associated with the following group: female, urban and aged 18~30 years. The "Out-sourced diet" pattern, consisting of mainly rice, steam bread and some processed meat, was associated with being male, urban and 18-30 years of age. These findings indicate that the dietary practice of the Tibetan people still has strong local characteristics, but it is also undergoing a dietary transition with the penetration of the Chinese Han diet and the increased consumption of outsourced (processed) foods. The unbalanced dietary intake of Tibetan residents should be taken seriously by all parties.


Assuntos
Dieta , Comportamento Alimentar , Adolescente , Adulto , Fatores Etários , Bebidas , Estudos Transversais , Inquéritos sobre Dietas , Ingestão de Alimentos , Feminino , Frutas , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Componente Principal , Recomendações Nutricionais , Rios , População Rural , Fatores Sexuais , Tibet , População Urbana , Verduras , Adulto Jovem
20.
Sci Total Environ ; 791: 148379, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34412395

RESUMO

Alpine grasslands play important functions in mitigating climate change and regulating water resources. However, the spatiotemporal variability of their carbon and water budgets remains unquantified. Here, 47 site-year observations of CO2 and water vapor fluxes (ET) are analyzed at sites situated along a hydrothermal gradient across the Qinghai-Tibetan Plateau, including an alpine wetland (wettest), an alpine shrub (coldest), an alpine meadow, an alpine meadow-steppe, and an alpine steppe (driest and warmest). The results show that the benchmarks for annual net ecosystem exchange (NEE) are -79.3, -77.8, -66.7, 20.2, and 100.9 g C m-2 year-1 at the meadow, shrub, meadow-steppe, steppe, and wetland, respectively. The peak daily NEE normalized by peak leaf area index converges to 0.93 g C m-2 d-1 at the 5 sites. Except in the wetland (722.8 mm), the benchmarks of annual ET fluctuate from 511.0 mm in the steppe to 589.2 mm in the meadow. Boosted regression trees-based analysis suggests that the enhanced vegetation index (EVI) and net radiation (Rn) determine the variations of growing season monthly CO2 fluxes and ET, respectively, although the effect is to some extent site-specific. Inter-annual variability in NEE, ecosystem respiration (RES), and ET are tightly (R2 > 0.60) related to the inter-growing season NEE, RES, and ET, respectively. Both annual RES and annual NEE are significantly constrained by annual gross primary productivity (GPP), with 85% of the per-unit GPP contributing to RES (R2 = 0.84) and 15% to NEE (R2 = 0.12). Annual GPP significantly correlates with annual ET alone at the drier sites of the meadow-steppe and the steppe, suggesting the coupling of carbon and water is moisture-dependent in alpine grasslands. Over half of the inter-annual spatial variability in GPP, RES, NEE, and ET is explained by EVI, atmospheric water vapor, topsoil water content, and bulk surface resistance (rs), respectively. Because the spatial variations of EVI and rs are strongly regulated by atmospheric water vapor (R2 = 0.48) and topsoil water content (R2 = 0.54), respectively, we conclude that atmospheric water vapor and topsoil water content, rather than the expected air/soil temperatures, drive the spatiotemporal variations in CO2 fluxes and ET across temperature-limited grasslands. These findings are critical for improving predictions of the carbon sequestration and water holding capacity of alpine grasslands.


Assuntos
Pradaria , Solo , Dióxido de Carbono , Ecossistema , Vapor , Tibet
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