Groundwater on the Tibetan Plateau is a critical water resource to people in Asia. However, its prevalence of antibiotic-resistant pathogens (ARPs), bacterial resistome and their driving factors remain unknown. Using metagenomics analysis, a hotspot of antibiotic-resistance genes (ARGs) and last-resort ARGs (LARGs) with a total of 639 subtypes was identified in the groundwater. Importantly, 164 metagenome-assembled genomes (MAGs) which possessed both ARGs and virulence factors (VFs) were assigned as potential ARPs, with the most abundant species being Acinetobacter johnsonii and Acinetobacter pittii. A total of 157 potential ARPs, involving Escherichia coli, were predicted as \"natural\" ARGs supercarriers. Thirty-six ARPs dominated by the genus Acinetobacter and Pseudomonas were found to harbour LARGs. Co-localizations of the ARG-mobile genetic elements (MGEs) showed that MGEs were significantly associated with ARGs in the ARPs, which suggests ARPs play a prominent role in ARG dissemination. Notably, latitudinal gradient is a driving factor in the occurrence of ARGs and ARPs. The average abundances of ARGs and ARP decreased as the latitude increased, with the highest abundance occurring in the region between 28.6◦N and 29.5◦N. MetaCompare further revealed health risks associated with the resistome decreased as the latitudes increased. These findings indicated different health risks associated with ARPs and bacterial resistome in latitudinal gradient groundwater. They raise the concerns of mitigating ARPs risk in groundwater on the Tibetan Plateau.

Responses of turfgrass to shade vary in individual species, and the degree and quality of low light; therefore, the selection of low light tolerant cultivars of turfgrass is important and beneficial for turf management rather than other practices. The stolons of thirteen bermudagrass genotypes were planted with two treatments and three replications of each treatment to establish for one month in the Yangzhou University Jiangsu China greenhouse. The established plants were transferred outside of the greenhouse, and 50% shading was applied to them with a black net. After 30 days of stress treatment, the morpho-physiological and biochemical analyses were performed. The expression of genes such as HEMA, HY5, PIF4, and Cu/ZnSOD was assessed. Cynodon dactylon is a C4, and perennial that grows as lawn grass and is used as forage. Based on different indicator measurements, the most shade-tolerant germplasm was L01 and L06 along the longitudes and L09 and L10 along the latitudes. At the same time, L02 and L08 were more susceptible, respectively. However, germplasm showed greater tolerance in higher latitudes while longitudinal plants showed less stress response. The current study aimed (1) to screen out the most shade-tolerant Cynodon dactylon genotype among 13 along longitudinal and latitudinal gradients in China. (2) to examine morpho-physiological indicators of different bermudagrassgenotypes; (3) to evaluate if and how differences in various indicators of bermudagrass correlated with geographic region. This study will significantly advance the use of Cynodon germplasm in breeding, genomics, management, nomenclature, and phylogeographical study. It will decisively define whether natural selection and migration can drive evolutionary responses for populations to adapt to their new environments effectively.

Plant phenology is influenced by a combined effect of phylogeny and climate, although it is yet unclear how these two variables work together to change phenology. We synthesized 107 previously published studies to examine whether phenological changes were impacted by both phylogeny and climate changes in various geographical settings globally. Phenological observation data from 52,463 plant species at 71 sites worldwide revealed that 90 % of phenological records showed phylogenetic conservation. i.e., closely related species exhibited similar phenology. To explore the significant and non-significant phylogenetic conservation between plant phenophases, our dataset comprises 5,47,000 observation records from the four main phenophases (leaf bud, leaf, flower, and fruit). Three-dimensional geographical distribution (altitude, latitude, and longitude) data analysis revealed that plant phenology may exhibit phylogenetic signals at finer special scales (optimal environmental conditions) that vanish in high altitude and latitude regions. Additionally, climatic sensitivity analysis suggested that phylogenetic signals were associated with plant phenophases and were stronger in the regions of ideal temperature (7-18 °C) and photoperiod (10-14 h) and weaker in harsh climatic conditions. These results show that phylogenetic conservation in plant phenological traits is frequently influenced by the interaction of harsh climatic conditions and geographical ranges. This meta-analysis enhances our knowledge of predicting species responses over geographic gradients under varied climatic conditions.

UNASSIGNED: Density management is a key silvicultural tool in management programs that enhances compositional and structural diversity and hence forest growth during the conversion of even-aged pure stands into mixed forests.
UNASSIGNED: To determine the optimum stand density, a model of maximum size-density relationships was employed to explore the relationship of the self-thinning trajectory with growth, species mixing, latitude, and site conditions during the transition of even-aged pure Chinese fir stands to Chinese fir-dominated mixed forests using stochastic frontier analysis. Data were obtained from a total of 591 permanent plots located in Fujian, Jiangxi, Zhejiang, and Anhui provinces in southern China.
UNASSIGNED: The results showed that (1) the slope of the maximum size-density relationship of Chinese fir-dominated mixed forests increased and plateaued over time; (2) the slope of the maximum size-density relationship of Chinese fir-dominated mixed forests did not deviate from Reineke\'s assumed universal slope of -1.605; and (3) mixing proportion had a positive effect on maximum size-density relationships, and latitude and site conditions had the opposite effect on maximum size-density relationships.
UNASSIGNED: Our findings will provide valuable guidance for the forest management of areas in which even-aged pure stands are being converted to mixed forests (i.e., when broadleaved tree species are planted after thinning to improve overall stand density and promote stand growth).

Survival of the immobile embryo in response to rising temperature is important to determine a species\' vulnerability to climate change. However, the collective effects of 2 key thermal characteristics associated with climate change (i.e., rising average temperature and acute heat events) on embryonic survival remain largely unexplored. We used empirical measurements and niche modeling to investigate how chronic and acute heat stress independently and collectively influence the embryonic survival of lizards across latitudes. We collected and bred lizards from 5 latitudes and incubated their eggs across a range of temperatures to quantify population-specific responses to chronic and acute heat stress. Using an embryonic development model parameterized with measured embryonic heat tolerances, we further identified a collective impact of embryonic chronic and acute heat tolerances on embryonic survival. We also incorporated embryonic chronic and acute heat tolerance in hybrid species distribution models to determine species\' range shifts under climate change. Embryos\' tolerance of chronic heat (T-chronic) remained consistent across latitudes, whereas their tolerance of acute heat (T-acute) was higher at high latitudes than at low latitudes. Tolerance of acute heat exerted a more pronounced influence than tolerance of chronic heat. In species distribution models, climate change led to the most significant habitat loss for each population and species in its low-latitude distribution. Consequently, habitat for populations across all latitudes will shift toward high latitudes. Our study also highlights the importance of considering embryonic survival under chronic and acute heat stresses to predict species\' vulnerability to climate change.
Efectos colectivos del aumento de las temperaturas promedio y los eventos de calor en embriones ovíparos Resumen La supervivencia de los embriones inmóviles en respuesta al incremento de temperatura es importante para determinar la vulnerabilidad de las especies al cambio climático. Sin embargo, los efectos colectivos de dos características térmicas claves asociadas con el cambio climático (i. e., aumento de temperatura promedio y eventos de calor agudo) sobre la supervivencia embrionaria permanecen en gran parte inexplorados. Utilizamos mediciones empíricas y modelos de nicho para investigar cómo el estrés térmico crónico y agudo influye de forma independiente y colectiva en la supervivencia embrionaria de los lagartos en todas las latitudes. Recolectamos y criamos lagartos de cinco latitudes e incubamos sus huevos en un rango de temperaturas para cuantificar las respuestas específicas de la población al estrés por calor crónico y agudo. Posteriormente, mediante un modelo de desarrollo embrionario parametrizado con mediciones de tolerancia embrionaria al calor, identificamos un impacto colectivo de las tolerancias embrionarias al calor agudo y crónico en la supervivencia embrionaria. También incorporamos la tolerancia embrionaria crónica y aguda al calor en modelos de distribución de especies híbridas para determinar los cambios de distribución de las especies bajo el cambio climático. La tolerancia embrionaria al calor crónico (T‐crónico) permaneció constante, mientras que la tolerancia al calor agudo (T‐agudo) fue mayor en latitudes altas que en latitudes bajas. La tolerancia al calor agudo ejerció una influencia más pronunciada que la tolerancia al calor crónico. En los modelos de distribución de especies, el cambio climático provocó la pérdida de hábitat más significativa para cada población y especie en su distribución de latitudes bajas. En consecuencia, el hábitat para poblaciones en todas las latitudes se desplazará a latitudes altas. Nuestro estudio también resalta la importancia de considerar la supervivencia embrionaria bajo estrés térmico crónico y agudo para predecir la vulnerabilidad de las especies al cambio climático.
动物胚胎在面对温度升高时的存活率对于确定气候变化下物种的脆弱性至关重要。然而, 与气候变化相关的两个关键温度特征(即平均气温升高和极端高温事件)对胚胎存活的整合影响仍然存在诸多未知。我们利用实验测定和生态位建模相结合的方式探究了慢性和急性热压力如何独立和共同影响不同纬度的蜥蜴胚胎存活率。我们从五个纬度采集并繁殖蜥蜴, 并在一定温度范围内孵化其受精卵以测定各个种群对慢性和急性热压力的耐受响应。我们根据测定的胚胎耐热特征构建胚胎发育模型, 进一步确定了胚胎的慢性和急性高温耐受对胚胎存活的整合影响。最后, 我们将胚胎的慢性和急性高温耐受纳入混合物种分布模型, 以确定未来气候变化对物种分布范围的影响。结果表明, 胚胎对慢性高温的耐受能力在不同纬度保持一致, 而对极端高温事件的耐受能力随纬度升高而增强。在决定胚胎存活时, 急性高温耐受能力比慢性高温耐受能力具有更显著的作用。在气候变化的影响下, 各种群或物种在其各自低纬度分布区的栖息地丧失最为严重, 所有纬度的蜥蜴种群或物种的适宜栖息地都将向高纬度方向转移。本研究强调了考虑胚胎在慢性和急性热压力下的存活对预测气候变化下物种脆弱性的重要性。.

Seawater density is an important physical property in oceanography that affects the accuracy of calculations such as gravity fields and tidal potentials and the calibration of acoustic and optical oceanographic sensors. In related studies, constant density values are frequently used, which can introduce significant errors. Therefore, this study employs a basic convolutional neural network model to construct a comprehensive model showing the seawater density distribution across the globe. The model takes into account depth, latitude, longitude, and month as inputs. Numerous real seawater datasets were used to train the model, and it has been shown that the model has an absolute mean error and root mean square error of less than 1 kg/m3 in 99% of the test set samples. The model effectively demonstrates the influence of input parameters on the distribution of seawater density. In this paper, we present a newly developed global model for distributing seawater density which is both comprehensive and accurate, surpassing previous models. The utilization of the model presented in this paper for estimating seawater density can minimize errors in theoretical ocean models and serve as a foundation for designing and analyzing ocean exploration systems.

Denitrification, anaerobic ammonium oxidation (anammox), and dissimilatory nitrate reduction to ammonium (DNRA) are three competing processes of microbial nitrate reduction that determine the degree of ecosystem nitrogen (N) loss versus recycling. However, the global patterns and drivers of relative contributions of these N cycling processes to soil or sediment nitrate reduction remain unknown, limiting our understanding of the global N balance and management. Here, we compiled a global dataset of 1570 observations from a wide range of terrestrial and aquatic ecosystems. We found that denitrification contributed up to 66.1% of total nitrate reduction globally, being significantly greater in estuarine and coastal ecosystems. Anammox and DNRA could account for 12.7% and 21.2% of total nitrate reduction, respectively. The contribution of denitrification to nitrate reduction increased with longitude, while the contribution of anammox and DNRA decreased. The local environmental factors controlling the relative contributions of the three N cycling processes to nitrate reduction included the concentrations of soil organic carbon, ammonium, nitrate, and ferrous iron. Our results underline the dominant role of denitrification over anammox and DNRA in ecosystem nitrate transformation, which is crucial to improving the current global soil N cycle model and achieving sustainable N management.

The morphological, physiological, and biochemical characteristics of leaves result from the long-term adaptation of plants to their environment and are closely related to plant growth and development. In this study, 37 prickly ash germplasm resources from 18 production areas were utilized as the subjects of research. Logistic equations, principal component analysis, and cluster analysis were employed to comprehensively evaluate the leaf traits of prickly ash germplasm resources, with an analysis of their correlation with ecological and geographical factors in the production areas. The results showed that the leaf traits of prickly ash germplasms of different origins are substantially different and diverse. The coefficient of variation for the 14 leaf traits was greater than 10%. The coefficient of variation of the compound leaflet number was the highest among all the considered leaf traits, and the coefficient of variation of leaf thickness was the lowest, at 49.86% and 11.37%, respectively. The leaf traits of the prickly ash germplasm originating from Chongqing in Yongchuan, Chongqing in Rongchang, and Yunnan in Honghe ranked highest, whereas the leaf traits of the prickly ash germplasm from Henan in Jiaozuo, Gansu in Tianshui, and Shanxi in Yuncheng ranked lowest. The results of the correlation analysis showed that among the ecological and geographical factors of the origins, latitude had the strongest correlation with the leaf traits of the prickly ash germplasm. As latitude increased, the leaves of prickly ash gradually decreased in size, weight, and leaf shape index. The factor with the second strongest correlation was temperature. The leaves of the prickly ash germplasm originating from warmer climate areas were larger and heavier than those from areas with colder climates. Altitude and longitude did not significantly affect the leaf traits of the prickly ash germplasm, but at similar latitudes, the leaves of the prickly ash germplasm in high-altitude areas were smaller, and the leaves of the prickly ash germplasm in low-altitude areas were larger. These findings can provide valuable references for breeding and the sustainable utilization of new varieties of prickly ash resources.

BACKGROUND: Vitamin D plays an important role in the health of adolescents, whereas vitamin D status of Chinese college students was seldom studied in China. To explore the vitamin D status and its relationship with ethnicity and geographic location in Chinese college students.
METHODS: The freshmen were taken a physical examination by trained medical personnel after they reported to university. Demographic information including age, gender, ethnicity, region of original residence was collected using a questionnaire survey. Serum 25(OH)D3 concentrations were measured using a liquid chromatograph mass spectrometer. Multiple regression analyses were used to explore the factors that influence serum 25(OH)D3 levels.
RESULTS: Totally 3220 freshmen who came from 26 provinces, autonomous districts or municipalities were recruited, with a mean age of 18.75 ± 1.18 years and 70.2% of them were female. The mean serum 25(OH)D3 levels were 18.51 ± 6.54 ng/mL, and the proportion of vitamin D deficiency (< 20 ng/mL) and insufficiency (20 ~  < 30 ng/mL) was 64.4% and 30.2%, respectively. The combined proportion of vitamin D deficiency and insufficiency was increased with the latitude increased. Miao had the highest serum 25(OH)D3 levels, whereas Kazak ethnic had the lowest (22.51 ng/mL vs. 13.94 ng/mL) among different ethnic groups. Female students, students from city, Uighur and Kazak ethnic, residing in high latitude was significantly associated with lower serum 25(OH)D3 levels (P < 0.05).
CONCLUSIONS: Vitamin D deficiency is an important health problem in Chinese college students. Sunlight activities, dietary and life-style intervention for college students according to geographic location and ethnicities should be considered.

Vitamin D deficiency is widespread in different populations and regions worldwide and has become a global health issue. The vitamin D status of the population in the Yunnan Province of Southwest China has not been evaluated to date. Therefore, in this study, we evaluated the vitamin D status according to the serum concentrations of 25-hydroxyvitamin D (25(OH)D) in individuals of Yunnan Province, a low-latitude, high-altitude and multiracial region in China. The data on 25(OH)D concentrations from October 2012 to December 2017 were retrospectively collected and assessed using the laboratory information system from 52 950 hospital-based participants (age, 1 day-96 years; females, 73.74%). The serum concentration of 25(OH)D was evaluated using a chemiluminescent immunoassay. The analysis was stratified by sex, age, sampling season, testing year, minority, residential district, latitude, altitude and meteorological factors. Vitamin D status was classified as follows: severe deficiency: <10 ng/mL; deficiency: <20 ng/mL; insufficiency: <30 ng/mL; and sufficiency: ≥30 ng/mL. The results showed that vitamin D deficiency is highly prevalent in Yunnan Province in a hospital-based cohort, with a deficiency and severe deficiency rate of 65.1% and a sufficiency rate of 5.30%. Significantly lower vitamin D levels and sufficiency rates were observed in females than in males (20.13 ± 7.22 ng/mL vs. 17.56 ± 6.66 ng/mL and 8.20% vs. 4.20%; p < 0.01, respectively); in spring and winter (16.93 ± 6.24 ng/mL; 2.97% and 16.38 ± 6.43 ng/mL; 3.06%, respectively) than in summer and autumn (20.23 ± 7.14 ng/mL; 8.02% and 19.10 ± 6.97 ng/mL; 6.61% [p < 0.01], respectively); and in older individuals (0-6 years: 28.29 ± 13.13 ng/mL vs. >60 years: 14.88 ± 8.39 ng/mL; p < 0.01). Relatively higher vitamin D levels were observed in individuals of Yi, Zhuang, Hani, Dai, Miao and Lisu minorities and lower levels in individuals of Hui and Zang minorities compared with those of the Han nationality (p < 0.01). The mean sunlight duration, mean air temperature, maximum ultraviolet value and latitude were significantly correlated with vitamin D levels (r = -0.53, 0.60, 0.31, -0.68, respectively; p < 0.05). These results suggest that vitamin D status is influenced by sex, age, minority, latitude and some meteorological factors in areas with high and low altitudes. Hence, new public health policies, such as advice on sunshine exposure, food fortification and nutrition education, as well as the implementation of vitamin D supplementation programmes must be considered to alleviate vitamin D deficiency in Yunnan province, Southwest China.