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Objectives: As one of the most common hereditary diseases, thalassemia affects a large number of people in China. The aim of this study was to investigate the feasibility of a method based on next-generation sequencing (NGS) for screening of thalassemia carriers among high school students in the Shaoguan area. Materials and Methods: The NGS-based method was performed using 25,910 high school students recruited from 38 schools. The screening yield was systematically analyzed. Before screening, a lecture on how the disease is inherited, the symptoms of thalassemia, and how to prevent it was given to 28,780 students. Results: Implying successful delivery of information on the disease, 90.03% (25,910 of 28,780) of the students agreed to join this program for thalassemia screening. A thalassemia carrier rate of 15.99% (4144 of 25,910) was found. Also, 69 rare genotypes (28 of α-thalassemia and 41 of β-thalassemia) and 9 novel variants were identified. Conclusions: This NGS-based method provided a feasible platform for high school population thalassemia screening. Combined with a clinical follow-up strategy, it could help eventually to prevent the births of affected children. [ABSTRACT FROM AUTHOR]

The ecosystem apparent quantum yield (α), maximum rate of gross CO2 assimilation (P max) and daytime ecosystem respiration rate (R d), reflecting the physiological functioning of ecosystem, are vital photosynthetic parameters for the estimation of ecosystem carbon budget. Climatic drivers may affect photosynthetic parameters both directly and indirectly by altering the response of vegetation. However, the relative contribution and regulation pathway of environmental and physiological controls remain unclear, especially in semi-arid grasslands. We analyzed seasonal and interannual variations of photosynthetic parameters derived from eddy-covariance observation in a typical semi-arid grassland in Inner Mongolia, Northern China, over 12 years from 2006 to 2017. Regression analyses and a structural equation model (SEM) were adopted to separate the contributions of environmental and physiological effects. The photosynthetic parameters showed unimodal seasonal patterns and significantly interannual variations. Variations of air temperature (T a) and soil water content (SWC) drove the seasonal patterns of photosynthetic parameters, while SWC predominated their interannual variations. Moreover, contrasting with the predominant roles of T a on α and R d, SWC explained more variance of P max than T a. Results of SEM revealed that environmental factors impacted photosynthetic parameters both directly and indirectly through regulating physiological responses reflected by stomatal conductance at the canopy level. Moreover, leaf area index (LAI) directly affected α , P max and R d and dominated the variation of P max. On the other hand, SWC influenced photosynthetic parameters indirectly through LAI and canopy surface conductance (gc). Our findings highlight the importance of physiological regulation on the photosynthetic parameters and carbon assimilation capacity, especially in water-limited grassland ecosystems. [ABSTRACT FROM AUTHOR]

Background: To investigate the risk factors and construct a logistic model and an extreme gradient boosting (XGBoost) model to compare the predictive performances for readmission in acute exacerbation of chronic obstructive pulmonary disease (AECOPD) patients within one year.Methods: In total, 636 patients with AECOPD were recruited and divided into readmission group (n = 449) and non-readmission group (n = 187). Backward stepwise regression method was used to analyze the risk factors for readmission. Data were divided into training set and testing set at a ratio of 7:3. Variables with statistical significance were included in the logistic model and variables with P < 0.1 were included in the XGBoost model, and receiver operator characteristic (ROC) curves were plotted.Results: Patients with acute exacerbations within the previous 1 year [odds ratio (OR) = 4.086, 95% confidence interval (CI) 2.723-6.133, P < 0.001), long-acting β agonist (LABA) application (OR = 4.550, 95% CI 1.587-13.042, P = 0.005), inhaled corticosteroids (ICS) application (OR = 0.227, 95% CI 0.076-0.672, P = 0.007), glutamic-pyruvic transaminase (ALT) level (OR = 0.985, 95% CI 0.971-0.999, P = 0.042), and total CAT score (OR = 1.091, 95% CI 1.048-1.136, P < 0.001) were associated with the risk of readmission. The AUC value of the logistic model was 0.743 (95% CI 0.692-0.795) in the training set and 0.699 (95% CI 0.617-0.780) in the testing set. The AUC value of XGBoost model was 0.814 (95% CI 0.812-0.815) in the training set and 0.722 (95% CI 0.720-0.725) in the testing set.Conclusions: The XGBoost model showed a better predictive value in predicting the risk of readmission within one year in the AECOPD patients than the logistic regression model. The findings of our study might help identify patients with a high risk of readmission within one year and provide timely treatment to prevent the reoccurrence of AECOPD. [ABSTRACT FROM AUTHOR]

Introduction: Thalassemia is one of the most common autosomal recessive inherited diseases worldwide, and it is also highly prevalent and variable in southern China. Various types of genetic testing technologies have been developed for diagnosis and screening of thalassemia. Characterized genomic DNA reference materials (RMs) are necessary for assay development, validation, proficiency testing, and quality assurance. However, there are no publicly available RMs for thalassemia genetic testing as yet. Methods: To address the need for the publicly available DNA RMs for thalassemia genetic testing, the National Institutes for Food and Drug Control and the China National GeneBank established 32 new cell lines with three wild‐type genotypes and 29 distinct genotypes of thalassemia which account for approximately 90% thalassemia carriers in China. The genomic DNA of 32 cell lines was characterized by four clinical genetic testing laboratories using different genetic testing methods and technology platforms. Results: The genotyping results are concordant among four laboratories. In addition, the results of stability test demonstrated that the genotypes of these DNA samples are not influenced by preanalytical conditions such as long‐term exposure to high‐temperature (37°C) environment and repeated freeze‐thawing. Conclusion: We developed the first national panel of 32 genomic DNA RMs which are renewable and publicly available for the quality assurance of various genetic testing methods and will facilitate research and development in thalassemia genetic testing. [ABSTRACT FROM AUTHOR]

α-Thalassemia (α-thal) is one of the most common genetic diseases in Southern China. Although more than 300 α-thal mutations have been reported in the world, the mutation spectrum is still not comprehensive. In this study, a novel mutation (HBA1: c.349G>T) in a newborn (proband) was first found by next-generation sequencing (NGS). Subsequently, hematological analysis and thalassemia genetic testing were performed for the family members. The results showed that both the proband and her mother were heterozygotes for this novel mutation and presented abnormal hematological indices. Based on the features observed in clinical practice, this novel mutation was considered as a type of α-thal variation. [ABSTRACT FROM AUTHOR]

We have developed a new method for non-invasive prenatal testing (NIPT) of paternally inherited fetal mutants for β-thalassemia (β-thal). Specially designed primer-introduced restriction analysis-polymerase chain reaction (PIRA-PCR) were used to detect four major mutations [IVS-II-654, HBB: c.316-197C > T; codon 17 (A > T), HBB: c.52A > T; −28 (A > G), HBB: c.-78A > G and codons 41/42 (-TTCT), HBB: c.126_129delCTTT] causing β-thal in China. The PIRA-PCR assay was first tested in a series of mixed DNA with different concentrations and mixed proportions. Subsequently, this assay was further tested in 10 plasma DNA samples collected from pregnant women. In the DNA mixture simulation test, the PIRA-PCR assay was able to detect 3.0% target genomic DNA (gDNA) mixed in 97.0% wild-type gDNA isolated from whole blood. For plasma DNA testing, the results detected by PIRA-PCR assay achieved 100.0% consistency with those obtained from the amniocentesis analysis. This new method could potentially be used for NIPT of paternally inherited fetal mutants for β-thal. [ABSTRACT FROM AUTHOR]

ABSTRACT Quantifying regional evapotranspiration (ET) and environmental constraints are particularly important for understanding water and carbon cycles of terrestrial ecosystems. However, a large uncertainty in the regional estimation of ET still remains for the terrestrial ecosystems in China. This study used ET measurements of 34 eddy covariance sites within China and adjacent regions to examine the performance of the revised Remote Sensing-Penman Monteith (RS-PM) model over various ecosystem types including forests, grasslands, wetlands and croplands. No significant systematic error was found in the revised RS-PM model predictions, which explained 61% of the ET variations at all of the validation sites. Regional patterns of ET at a spatial resolution of 10 × 10 km were quantified using a meteorology dataset from 753 meteorological stations, Modern Era Retrospective-analysis for Research and Applications (MERRA) reanalysis products and satellite data such as the Advanced Very High Resolution Radiometer (AVHRR) leaf area index. ET decreased from the southeast of China toward the northwest. Relatively high ET values were found in the southern China such as Yunnan, Hainan, Fujian and Guangdong Provinces, whereas low ET values occurred in northwestern China such as in the Xinjiang autonomous region. On average, the annual ET presented an increasing trend during the 1982-2009, with relatively low ET in 1985, 1993, 1997, 2000 and 2009. We found that the mean annual ET was higher than world average, ranging spatially between 484 and 521 mm yr−1, with a mean value of 500 mm yr−1, which accounted for approximately 5·6-8·3% of the world's total land-surface ET. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The Eurasian steppe has long been subject to grazing by domestic ungulates at high levels, resulting in widespread deterioration of biodiversity and ecosystem services. While abundant evidence demonstrates that heavy grazing alters the ecosystem structure and function of grasslands, research on how grazing specifically affects ecosystem functioning and stoichiometry on broad scales is scarce because of a lack of adequate ungrazed reference sites., We examined the effects of grazing on ecosystem functioning and C : N : P stoichiometry across a precipitation gradient along the 700 km China- Mongolia transect ( CMT), covering three community types: meadow steppe, typical steppe and desert steppe., Long-term grazing has dramatically altered the C, N and P pools and stoichiometry of steppe ecosystems along the CMT. Grazing reduced the C, N and P pools in above-ground biomass and litter, while the responses in below-ground biomass and soil C, N and P pools to grazing differed substantially among community types., Grazing increased N content and decreased C : N ratios in all plant compartments, suggesting accelerated N cycling. The altered C : N : P stoichiometry may be explained by changes in the composition of species and functional groups as well as increased foliar N and P contents for the same species in grazed communities., Synthesis and applications. Plant stoichiometric responses to grazing ranged from large in the meadow steppe to small in the typical steppe to generally insignificant in the desert steppe, implying that different underlying mechanisms operated along the regional precipitation gradient. Our findings suggest that reducing the stocking rate and restoring the vastly degraded steppes are essential to sustain native steppe biodiversity, ecosystem functioning and biological capacity for mitigating the impact of climate change in the Inner Mongolia grassland. [ABSTRACT FROM AUTHOR]

Background and aims Changes in supplies of resources will modify plant functional traits. However, few experimental studies have addressed the effects of nitrogen and water variations, either singly or in combination, on functional traits. Methods A 2-year field experiment was conducted to test the effects of nitrogen and water addition on leaf longevity and other functional traits of the two dominant (Agropyron cristatum and Stipa krylovii) and three most common species (Cleistogenes squarrosa, Melilotoides ruthenica and Potentilla tanacetifolia) in a temperate steppe in northern China. Key Results Additional nitrogen and water increased leaf nitrogen content and net photosynthetic rate, and changed other measured functional traits. Leaf longevity decreased significantly with both nitrogen addition (–6 days in 2007 and –5·4 days in 2008; both P < 0·001) and watering (–13 days in 2007 and –9·9 days in 2008; both P < 0·001), and significant differences in leaf longevity were also found among species. Nitrogen and water interacted to affect leaf longevity and other functional traits. Soil water content explained approx. 70 % of the shifts in leaf longevity. Biomass at both species and community level increased under water and nitrogen addition because of the increase in leaf biomass production per individual plant. Conclusions The results suggest that additional nitrogen and water supplies reduce plant leaf longevity. Soil water availability might play a fundamental role in determining leaf longevity and other leaf functional traits, and its effects can be modified by soil nitrogen availability in semi-arid areas. The different responses of species to resource alterations may cause different global change ramifications under future climate change scenarios. [ABSTRACT FROM AUTHOR]

Abstract: Land use change and grassland degradation are two of the most critical problems ubiquitously found in arid and semi-arid areas in Northern China. Energy fluxes, including net radiation (R n), latent heat flux (LE), sensible heat flux (H) and soil heat flux (G), were examined over an entire year (December 2005 to November 2006) in different steppe ecosystems – the steppe and cropland in Duolun and the fenced and grazed steppe in Xilinhot – in Inner Mongolia based on direct measurements from four eddy-covariance flux towers. The seasonal changes in R n, LE, H and G of the four sites were similar, with very low values during the period of snow cover from December to February, followed by a gradual increase in the growing season. The opposite seasonal patterns of the LE and H fraction resulted in significant seasonal changes in Bowen ratio (β). Human activity in cropland ecosystems not only resulted in a rapidly shift between LE and H, but also triggered a decrease in latent heat fraction because of a shortened growing season of crop plants. The significantly positive relationships between canopy surface conductance (g c) and LE/LEeq of all of the study sites suggested that a lack of precipitation coupled with high VPD conduced remarkable decreases of stomatal conductance. This could impede the latent heat partitioning of available energy (R n − G) in semi-arid ecosystems, Inner Mongolia. The obvious decrease in the values of g c and the decoupling factor (Ω) in both the cropland and the degraded steppe suggested that land use change could depress latent flux fraction and increase its sensitivity to air and soil drought. [Copyright &y& Elsevier]

• Temperate and alpine grasslands were weak carbon sinks. • Elevated water consistently increased carbon fluxes in temperate and alpine grasslands. • Increased temperature reduced carbon fluxes in temperate grasslands and increased carbon fluxes in alpine grasslands. Temperate grassland (TG) and alpine grassland (AG) are two distinct grassland types with different climatic backgrounds and adaptation patterns. Little is known about the universal and divergent responses of TGs and AGs to climate change, particularly with regard to the carbon (C) fluxes. The large-scale responses of the C fluxes in different grasslands to climate change remain unclear, with only a few comparative studies of distinct responses of the C fluxes in TGs and AGs to climate change hinders our understanding of this subject. In this study, we conducted a large-scale transect study across the Mongolian, Loess, and Tibetan Plateaus in China to reveal the similarities and differences in the responses of the C fluxes in TGs and AGs to climate change. We used C flux data measured by eddy covariance from ChinaFLUX and published literature, covering the period from 2003 to 2020. The results showed that TGs and AGs in China were weak C sinks. Net ecosystem productivity in TGs and AGs exhibited opposite trends with increasing latitude, longitude, and altitude. Elevated water (mean annual precipitation and soil water content) consistently increased the C fluxes. Conversely, increased temperature (mean annual temperature and mean annual soil temperature) reduced the C fluxes in TGs and increased the C fluxes in AGs. The water factors promoted the C fluxes in both TGs and AGs by improving the leaf area indices. Conversely, the temperature factors had a strong direct, negative effect on the C fluxes in TGs and a weak direct, positive effect on the C fluxes in AGs, emphasizing the divergent patterns of the C fluxes in TGs and AGs and their responses to climate change. Overall, this study enhances our knowledge on C sinks and various grassland hydrothermal sensitivities. [ABSTRACT FROM AUTHOR]

• The β of terrestrial ecosystems in China varied among ecosystem types. • The β of terrestrial ecosystems in China increased linearly with latitude. • Climate-shaped vegetation factors dominated the spatial variation in β. • Lower hydrothermal conditions limit the importance of vegetation factors to β. The Bowen ratio (β), which is the ratio of sensible heat (H) to latent heat (LE), reflects the energy balance and partitioning processes among soil, vegetation, and the atmosphere. Although the spatial patterns of β have been clearly delineated, the importance of vegetation in the spatial variation of β is frequently underestimated. Revealing the spatial patterns of β would improve the understanding of the variation in energy partitioning in terrestrial ecosystems and its reciprocal relationship with environmental change. Here, we calculated β by integrating H and LE flux values from 80 flux observation sites based on the eddy-covariance method in ChinaFLUX to analyze the spatial pattern and mechanism of β in China. Terrestrial ecosystems in China had an average β of 0.64 ± 0.47. β varied significantly among ecosystem types. Deserts had the highest β (2.08 ± 0.17), while wetlands had the lowest β (0.37 ± 0.11). The β values of terrestrial ecosystems exhibited a significant latitudinal pattern, increasing linearly with latitude. This pattern also existed in forest and cropland ecosystems. The spatial pattern of β was dominated by climate-shaped vegetation factors, including leaf area index (LAI) and fractional vegetation cover (FVC). Nevertheless, as water and thermal conditions decline, the contribution of vegetation factors gradually wanes. These findings demonstrated the spatial variations and driving mechanisms of terrestrial ecosystem β and provided insights into the mitigation of future climate change by vegetation. [ABSTRACT FROM AUTHOR]

Smart, real-time, low-cost, and distributed ecosystem monitoring is essential for understanding and managing rapidly changing ecosystems. However, new techniques in the big data era have rarely been introduced into operational ecosystem monitoring, particularly for fragile ecosystems in remote areas. We introduce the Internet of Things (IoT) techniques to establish a prototype ecosystem monitoring system by developing innovative smart devices and using IoT technologies for ecosystem monitoring in isolated environments. The developed smart devices include four categories: large-scale and nonintrusive instruments to measure evapotranspiration and soil moisture, in situ observing systems for CO 2 and δ 13C associated with soil respiration, portable and distributed devices for monitoring vegetation variables, and Bi-CMOS cameras and pressure trigger sensors for terrestrial vertebrate monitoring. These new devices outperform conventional devices and are connected to each other via wireless communication networks. The breakthroughs in the ecosystem monitoring IoT include new data loggers and long-distance wireless sensor network technology that supports the rapid transmission of data from devices to wireless networks. The applicability of this ecosystem monitoring IoT is verified in three fragile ecosystems, including a karst rocky desertification area, the National Park for Amur Tigers, and the oasis-desert ecotone in China. By integrating these devices and technologies with an ecosystem monitoring information system, a seamless data acquisition, transmission, processing, and application IoT is created. The establishment of this ecosystem monitoring IoT will serve as a new paradigm for ecosystem monitoring and therefore provide a platform for ecosystem management and decision making in the era of big data. [ABSTRACT FROM AUTHOR]

• Energy partitioning regime transferred from H- to LE-dominated along the aridity gradient. • The role of vegetation in energy partitioning was strengthened from desert to meadow steppes. • Response of β to climate and vegetation factors was more sensitive with increasing aridity. Surface energy exchange is vital because it affects microclimate, water cycle and biogeochemical processes in the canopy-atmosphere interface. In this study, seasonal variations and regulators of energy fluxes and partitioning were investigated based on a long-term eddy flux observation dataset (12 towers, 82 site-years in total) along an aridity gradient in temperate grasslands of Northern China. Our results showed that the net radiation (R n) and all energy components, including latent heat (LE), sensible heat (H) and ground heat (G 0) fluxes, presented unimodal seasonal patterns across different grassland types, with R n and LE peaked in the middle growing season but H and G 0 at the beginning of the growing season. The energy partitioning shifted from the H-dominated to the LE-dominated period accompanied vegetation phenological development, thus a U-shaped seasonal pattern of Bowen ratio (β, H/LE) was observed. Prolonged LE-dominated period and great peak of LE flux enhanced LE/R n proportion and decreased β from desert steppes to typical steppes and meadow steppes. Climate and vegetation factors co-regulated the seasonal patterns of energy fluxes and partitioning, with enhanced effects of LAI and canopy surface conductance (g c) from desert steppes to typical and meadow steppes, but a reverse pattern of land-atmosphere coupling via vegetation physiological regulation. Meanwhile, enhanced sensitivity of β in response to variations of climate and vegetation factors was also observed with increasing aridity. Our founding highlighted the role of vegetation especially physiological regulation in determining the seasonal patterns of energy fluxes and partitioning in water-limited grasslands. Whereas, the great sensitivity of energy partitioning to vegetation changing with increasing aridity also emphasized that it is vital to pay attention to the response of energy exchange in the desert steppes to the greening trend in Northern China under future climate scenarios. [ABSTRACT FROM AUTHOR]

Soil on the earth has been estimated to sequester around 5.4% of total carbon (C), most of it as soil organic carbon (SOC), but the exact amount of and relevant mechanisms for the stock of SOC are far from clear. In this study, we assessed how topography and grazing influenced distribution of SOC, and soil total nitrogen (STN) in grasslands in the hilly and mountainous regions of northern China. Soil parameters (soil organic C and N content, pH value, gravel content, and bulk density in 50 cm soil depth) and topographic elements (slope aspect, position and inclination) were investigated at 171 sites. Results from model selection of generalized additive model (GAM) procedure showed the model with integration of topographic factors had strong predictability on the distribution of SOC and STN. This indicated that topography was an important driving factor for distribution of SOC and STN. Both SOC and STN storage were observed higher on shadow slopes and at the middle position of slopes. Although slope inclination had no direct effects on SOC and STN storage, it showed significant effects on soil pH value, gravel content and bulk density, which were significantly negatively correlated with stock of SOC and STN. Besides, the long history of grazing throughout the study area was also found to have significant negative effects on storage of SOC and STN, suggesting weakened relationship between topography and SOC and STN stocks. Our results indicate that topography, in combination with human activities such as grazing, has significant effects on storage of soil C and N either directly or indirectly via changing soil physico-chemical properties. Our study can help to understand the pattern of the topography effects on the storage of SOC and STN in grasslands with patchy distributions in the hilly and mountainous regions of the north China. [ABSTRACT FROM AUTHOR]

Recent evidences show that terrestrial biogeochemical models have large uncertainty in estimating climate-change effect on grassland net ecosystem productivity (NEP), which is defined as the difference between gross ecosystem photosynthesis (GEP) and respiration (ER). It remains unclear that whether GEP or ER limits the model capability to simulate NEP responses to climate change in semiarid grasslands. Given the surrogate CENTURY-type model is widely used for Earth system modeling, we investigated two of them (i.e., DAYCENT and TECO models) and examined which processes dominate their ability to capture the responses of NEP to experimental climate changes in a temperate steppe of northern China. During the simulation from 2006 to 2008, the two models captured the observed mean annual NEP in the control plots when they were validated by the observations from an adjacent eddy-flux tower. However, they failed to capture the treatment effects of experimental warming and increased precipitation on NEP because of the poor estimations of ER responses. DAYCENT model simulated a higher precipitation effect on ER (37.83%) and TECO model overestimated the warming effect on ER by 8.18%. The simulation of treatment effects on ER and therefore NEP can be improved by an optimized parameterization of the water-related decay functions for soil organic carbon (C). The simulated cumulative loss of total ecosystem C stock during 2010–2100 were decreased when the TECO model used experiment-fitted parameters (0.72 kg C m −2 ) instead of using the initial validation with eddy-flux data (0.96 kg C m −2 ). The ecosystem shifted from C sink to source at threshold of 435 mm of annual total precipitation. Our findings indicate that future projection of C cycle in semiarid grasslands could be improved by better understanding of water response of ecosystem respiratory processes. [ABSTRACT FROM AUTHOR]

Highlights: [•] We developed a predictive model for estimating NEP in the grasslands of northern China. [•] The northern China's grasslands had a net carbon uptake of 158±25gCm−2 growing season−1. [•] On average, the regional NEP was 126TgCgrowing season−1 during 2000–2010. [•] Interannual variations of net carbon uptake were sensitive to precipitation and drought. [ABSTRACT FROM AUTHOR]

Highlights: [•] We synthesize flux observations from 22 eddy covariance sites across China. [•] Annual carbon and water fluxes generally decline with increasing latitude. [•] The patterns are controlled by temperature, precipitation, and growing season length. [•] Plantations and coastal wetlands have high carbon sequestration capacity and WUE. [•] Efforts to strengthen C sink should focus on forest plantations in southern China. [ABSTRACT FROM AUTHOR]

Abstract: Phenological changes are closely related to the carbon cycle of terrestrial ecosystems, and satellite data have been widely used in large scale phenological research. Numerous methods have been developed to reconstruct distinct satellite derived vegetation signals from continuous vegetation index time series and to track the points corresponding to important phenological events. In this study, we perform a multiple-method investigation of the spring vegetation growth onset phenology in temperate China north of 30°N with NDVI (normalized difference vegetation index) data produced from SPOT satellites. The results indicated that the spring onset dates estimated from five different methods show similar spatial pattern along latitudinal or altitudinal gradients, but with significant variances in the dates. In most areas (76% of pixels), the standard deviation (SD) of the estimated spring onset dates from different methods is within one month, while in a few places (2% of pixels), mostly agricultural cropland, the SD is more than 60 days. Comparing the satellite derived green-up onset dates against the gross primary productivity (GPP) time series curves acquired from six eddy covariance towers further highlights the strengths and limits of different methods in estimating phenological events. In a vast region with diverse vegetation types and physical environment, it is critical to choose the “right” method for the “right” place. Generally climate factors such as temperature and precipitation play an important role in controlling the start of vegetation growth in temperate China. Yet this climate-phenology relationship varies largely across different regions and vegetation types. [Copyright &y& Elsevier]

Poplar plantation is the most dominant broadleaf forest type in northern China. Since the mid-1990s plantation was intensified to combat desertification along China's northwestern border, i.e., within Inner Mongolia (IM). This evoked much concern regarding the ecological and environmental effects on areas that naturally grow grass or shrub vegetation. To highlight potential consequences of large-scale poplar plantations on the water budget within semiarid IM, we compared the growing season water balance (evapotranspiration (ET) and precipitation (PPT)) of a 3-yr old poplar plantation (Kp3) and a natural shrubland (Ks) in the Kubuqi Desert in western IM, and a 6-yr old poplar plantation (Bp6) growing under sub-humid climate near Beijing. The results showed that, despite 33% lower PPT at Kp3, ET was 2% higher at Kp3 (228mm) as compared with Ks (223mm) in May¿September 2006. The difference derived mainly from higher ET at the plantation during drier periods of the growing season, which also indicated that the poplars must have partly transpired groundwater. Estimated growing season ET at Bp6 was about 550mm and more than 100% higher than at Kp3. It is estimated that increases in leaf area index and net radiation at Kp3 provide future potential for the poplars in Kubuqi to exceed the present ET and ET of the natural shrubland by 100¿200%. These increases in ET are only possible through the permanent use of groundwater either directly by the trees or through increased irrigation. This may significantly change the water balance in the area (e.g., high ET at the cost of a reduction in the water table), which renders large-scale plantations a questionable tool in sustainable arid-land management. [Copyright &y& Elsevier]

• Spaceborne SIF can accurately respond to drought onset and recovery. • Spaceborne SIF can precisely detect stability of grasslands to drought. • MODIS VNIR data underestimate stability of Inner Mongolia grasslands to drought. Currently, stability of grassland ecosystem is facing serious challenges due to the occurrence of global warming and the increased frequency and intensity of extreme droughts. The stability of grassland ecosystem has two distinct components: 'resistance' and 'resilience'. However, the evaluation of resistance and resilience mechanisms is hindered by the lack of tools for accurately monitoring the response of grasslands to drought across spatio-temporal scales. In this study, the resistance and resilience of grassland ecosystem are investigated by combining multi-source data, including space-borne solar-induced chlorophyll fluorescence (SIF), Gross Primary Productivity (GPP) estimated by flux towers, and MODIS visible near-infrared (VNIR) data. The characteristics of grassland ecosystem resistance and resilience to drought are obtained from the grasslands of Inner Mongolia, China, which suffered from a prolonged scarcity of rainfall in 2009. Space-borne SIF is found to be a beneficial tool for monitoring the seasonal dynamics of vegetation productivity compared to MODIS VNIR data. Space-borne SIF features a higher accuracy for monitoring the recovery time, resistance and resilience of grasslands to drought compared to MODIS VNIR data. Spatially, the resilience of Inner Mongolia grasslands to drought measured by SIF is greater than that measured by MODIS VNIR data, while the resistance of Inner Mongolia grasslands to drought measured by SIF is less than that measured by MODIS VNIR data. Moreover, areas with high resistance are located at the interlaced zone of grassland ecosystem and farmland or forest, where the resilience is low. These results demonstrate that space-borne SIF has great potential for monitoring the resistance and resilience of grasslands in response to drought over large regions. [ABSTRACT FROM AUTHOR]

Gross ammonification (GA) and gross nitrification (GN) are key regulators of the bioavailability of nitrogen (N) in terrestrial ecosystems. In arid and semi-arid grassland ecosystems, the impacts of precipitation change on in situ GA and GN and their seasonal variations are understudied. A manipulative experiment with five precipitation levels (−60%, −30%, unchanged ambient precipitation as control, +30%, +60% of ambient precipitation) was set up in May 2012. After a 2-year equilibration period, the 15N pool dilution technique was applied to determine GA and GN rates in surface soil (0–5 cm) within 8 sampling dates ranging from the onset to the end of the growing season. Pronounced temporal variability of GA and GN rates were observed with the highest GA and GN rates in the mid-growing season (August) and the lowest in the post-growing season (October). GA rates during the growing season were primarily controlled by precipitation and soil water availability, while this effect diminished at the onset and end of the growing season when the temperature dropped. In contrast, GN was predominately controlled by ammonium (NH 4 +) production through GA. In the peak-growing season, the +60% precipitation treatment enhanced GA and GN rates by up to 4-fold, while the −30% precipitation treatment marginally suppressed GA and GN rates. The −60% precipitation treatment suppressed GA and GN rates to below detection limits across the entire study period, suggesting that extreme and persistent droughts greatly inhibited N turnover in the surface soil, thereby forcing plants to mobilize and access nutrients from deeper soil layers. Our findings provide a season-specific mechanistic insight into precipitation impacts on topsoil gross N turnover and suggest that the N cycling represented in ecosystem models needs to consider a mechanism that allows a strong suppression of microbial functions under extreme droughts. • Gross ammonification/nitrification (GA/GN) was strengthened by precipitation. • Temperature is limiting GA before and after the growing season. • GN is tightly coupled to substrate supply by GA. • Extreme drought with 60% precipitation reduction might terminate GA and GN. [ABSTRACT FROM AUTHOR]

The intricate mechanisms controlling plant diversity and community composition are cornerstone of ecological understanding. Yet, the role of mycorrhizal symbiosis in influencing community composition has often been underestimated. Here, we use extensive species survey data from 1315 grassland sites in China to elucidate the influence of mycorrhizal symbiosis on plant phylogenetic diversity and community assembly. We show that increasing mycorrhizal symbiotic potential leads to greater phylogenetic dispersion within plant communities. Mycorrhizal species predominantly influence deterministic processes, suggesting a role in niche-based community assembly. Conversely, non-mycorrhizal species exert a stronger influence on stochastic processes, highlighting the importance of random events in shaping community structure. These results underscore the crucial but often hidden role of mycorrhizal symbiosis in driving plant community diversity and assembly. This study provides valuable insights into the mechanisms shaping ecological communities and the way for more informed conservation that acknowledges the complex interplay between symbiosis and community dynamics., (© 2024 John Wiley & Sons Ltd.)

Here we report a novel β-globin gene mutation in the promoter ( HBB :c.-139&#95;-138delAC) detected by next-generation sequencing (NGS). The proband was a 28-year-old Chinese male, living in Shenzhen City, Guangdong Province, who originates from Hunan Province. The red cell indices were almost normal, with a slightly decreased Red Cell volume Distribution Width(RDW). Capillary electrophoresis (CE) showed the Hb A (93.1%) value was below normal, while the Hb A 2 (4.2%) and Hb F (2.7%) values were both beyond normal. A set of genetic tests of the α and β-globin genes were then performed to determine whether the subject carried any causative mutations. The results of NGS revealed a two-base pair deletion at position -89 to -88( HBB :c.-139&#95;-138delAC）in the heterozygous state, which was subsequently confirmed by Sanger sequencing.

Enhancing the terrestrial ecosystem carbon sink (referred to as terrestrial C sink) is an important way to slow down the continuous increase in atmospheric carbon dioxide (CO 2 ) concentration and to achieve carbon neutrality target. To better understand the characteristics of terrestrial C sinks and their contribution to carbon neutrality, this review summarizes major progress in terrestrial C budget researches during the past decades, clarifies spatial patterns and drivers of terrestrial C sources and sinks in China and around the world, and examines the role of terrestrial C sinks in achieving carbon neutrality target. According to recent studies, the global terrestrial C sink has been increasing from a source of (-0.2±0.9) Pg C yr -1 (1 Pg=10 15 g) in the 1960s to a sink of (1.9±1.1) Pg C yr -1 in the 2010s. By synthesizing the published data, we estimate terrestrial C sink of 0.20-0.25 Pg C yr -1 in China during the past decades, and predict it to be 0.15-0.52 Pg C yr -1 by 2060. The terrestrial C sinks are mainly located in the mid- and high latitudes of the Northern Hemisphere, while tropical regions act as a weak C sink or source. The C balance differs much among ecosystem types: forest is the major C sink; shrubland, wetland and farmland soil act as C sinks; and whether the grassland functions as C sink or source remains unclear. Desert might be a C sink, but the magnitude and the associated mechanisms are still controversial. Elevated atmospheric CO 2 concentration, nitrogen deposition, climate change, and land cover change are the main drivers of terrestrial C sinks, while other factors such as fires and aerosols would also affect ecosystem C balance. The driving factors of terrestrial C sink differ among regions. Elevated CO 2 concentration and climate change are major drivers of the C sinks in North America and Europe, while afforestation and ecological restoration are additionally important forcing factors of terrestrial C sinks in China. For future studies, we recommend the necessity for intensive and long term ecosystem C monitoring over broad geographic scale to improve terrestrial biosphere models for accurately evaluating terrestrial C budget and its dynamics under various climate change and policy scenarios., (© 2022. Science China Press and Springer-Verlag GmbH Germany, part of Springer Nature.)

In this study, we report two novel thalassemia variants detected in Chinese individuals using targeted NGS technology. We detected a novel frameshift variant, HBB : c.181delG, in a 32-year-old Chinese individual. This novel variant [a single nucleotide deletion at nucleotide 181 of codon 60 (-G)], was detected by targeted next generation sequencing (NGS), resulting in a stop codon at codon 60 in exon 2 of the HBB gene. The impact of this novel variant was further analyzed by an in vitro model. We also identified a novel in-frame variant, HBA1 : c.121&#95;126delAAGACC [codons 40/41 (-AAGACC)], in another Chinese individual in this study. We named these two novel variants, HBB : c.181delG and HBA1 : c.121&#95;126delAAGACC according to the Human Genome Variation Society (HGVS), which were detected by the first author. These two novel variants have expanded the mutation spectrum of thalassemia and it would be beneficial for carrier screening, genetic counseling and prenatal diagnosis (PND) of thalassemia.

We detected a novel frameshift variant ( HBA1 : c.263delA) and - - SEA (Southeast Asian), deletion in a 28-year-old Chinese woman with α-thalassemia (α-thal). This novel variant (a single nucleotide deletion at nucleotide 263 of codon 87) was detected by targeted next generation sequencing (NSG), resulting in a stop codon at amino acid 102 in exon 2 of the HBA1 gene. We also identified a novel heterozygous insertion ( HBA2 : c.376dupC) in a 24-year-old Chinese woman through screening for thalassemia. These two novel variants have expanded the mutation spectrum of α-thal and it would be beneficial for carrier screening, genetic counseling and prenatal diagnosis (PND) of α-thal.

Hemoglobinopathies are the most common monogenic disorders worldwide. Substantial effort has been made to establish databases to record complete mutation spectra causing or modifying this group of diseases. We present a variant database which couples an online auxiliary diagnosis and at-risk assessment system for hemoglobinopathies (DASH). The database was integrated into the Leiden Open Variation Database (LOVD), in which we included all reported variants focusing on a Chinese population by literature peer review-curation and existing databases, such as HbVar and IthaGenes. In addition, comprehensive mutation data generated by high-throughput sequencing of 2,087 hemoglobinopathy patients and 20,222 general individuals from southern China were also incorporated into the database. These sequencing data enabled us to observe disease-causing and modifier variants responsible for hemoglobinopathies in bulk. Currently, 371 unique variants have been recorded; 265 of 371 were described as disease-causing variants, whereas 106 were defined as modifier variants, including 34 functional variants identified by a quantitative trait association study of this high-throughput sequencing data. Due to the availability of a comprehensive phenotype-genotype data set, DASH has been established to automatically provide accurate suggestions on diagnosis and genetic counseling of hemoglobinopathies. LOVD-DASH will inspire us to deal with clinical genotyping and molecular screening for other Mendelian disorders., (© 2019 The Authors. Human Mutation Published by Wiley Periodicals, Inc.)

Objectives: Thalassemia is a highly prevalent monogenic inherited disease in southern China. It is important to collect epidemiological data comprehensively for proper prevention and treatment., Methods: In this study, blood samples collected from 15 807 residents of Chenzhou were primarily screened by hematological tests. A total of 3973 samples of suspected thalassemia carriers were further characterized by combined next-generation sequencing (NGS) and Gap-PCR., Results: In total, 1704 subjects were diagnosed as thalassemia carriers with a total prevalence rate of 10.78%, including 943 α-thalassemia carriers, 708 β-thalassemia carriers, and 53 composite α and β-thalassemia carriers. The prevalence rates of α-thalassemia, β-thalassemia, and composite α and β-thalassemia were 5.97%, 4.48%, and 0.34%, respectively. Meanwhile, we characterized 19 α-thalassemia variations and 21 β-thalassemia variations in thalassemia carriers. Approximately 2.88% of thalassemia carriers would be missed by traditional genetic analysis. In addition, four novel thalassemia mutations and one novel abnormal hemoglobin mutation were identified., Conclusions: Our data suggest a high prevalence of thalassemia and a diverse spectrum of thalassemia-associated variations in Chenzhou. Also, combined NGS and Gap-PCR is an effective thalassemia screening method. Our findings might be helpful for prevention and treatment of thalassemia in this region., (© 2019 The Authors. Journal of Clinical Laboratory Analysis Published by Wiley Periodicals, Inc.)

Grazing profoundly influences vegetation and the subsequent carbon fluxes in various ecosystems. However, little effort has been made to explore the underlying mechanisms for phenological changes and their consequences on carbon fluxes at ecosystem level, especially under the coupled influences of human disturbances and climate change. Here, a manipulative experiment (2012-2013) was conducted to examine both the independent and interactive effects of grazing and watering on carbon fluxes across phenological phases in a desert steppe. Grazing advanced or delayed phenological timing, leading to a shortened green-up phase (GrP: 23.60 days) in 2013 and browning phase (BrP: 12.48 days) in 2012 from high grazing, and insignificant effects on the reproductive phase (ReP) in either year. High grazing significantly enhance carbon uptake, while light grazing reduce carbon uptake in ReP. Watering only delayed the browning time by 5.01 days in 2013, producing no significant effects on any phenophase. Watering promoted the net ecosystem exchange (NEE), ecosystem respiration (ER), and gross ecosystem productivity (GEP) only in the GrP. When calculating the yearly differences in phenophases and the corresponding carbon fluxes, we found that an extended GrP greatly enhanced NEE, but a prolonged ReP distinctly reduced it. The extended GrP also significantly promote GEP. Increases in growing season length appeared promoting ER, regardless of any phenophase. Additionally, the shifts in NEE appeared dependent of the variations in leaf area index (LAI)., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Both water and nitrogen (N) availability have significant effects on ecosystem CO2 exchange (ECE), which includes net ecosystem productivity (NEP), ecosystem respiration (ER) and gross ecosystem photosynthesis (GEP). How water and N availability influence ECE in arid and semiarid grasslands is still uncertain. A manipulative experiment with additions of rainfall, snow and N was conducted to test their effects on ECE in a semiarid temperate steppe of northern China for three consecutive years with contrasting natural precipitation. ECE increased with annual precipitation but approached peak values at different precipitation amount. Water addition, especially summer water addition, had significantly positive effects on ECE in years when the natural precipitation was normal or below normal, but showed trivial effect on GEP when the natural precipitation was above normal as effects on ER and NEP offset one another. Nitrogen addition exerted non-significant or negative effects on ECE when precipitation was low but switched to a positive effect when precipitation was high, indicating N effect triggered by water availability. Our results indicate that both water and N availability control ECE and the effects of future precipitation changes and increasing N deposition will depend on how they can change collaboratively in this semiarid steppe ecosystem.

Variations in the carbon isotope signature of leaf dark-respired CO2 (δ13CR) within a single night is a widely observed phenomenon. However, it is unclear whether there are plant functional type differences with regard to the amplitude of the nighttime variation in δ13CR. These differences, if present, would be important for interpreting the short-term variations in the stable carbon signature of ecosystem respiration and the partitioning of carbon fluxes. To assess the plant functional type differences relating to the magnitude of the nighttime variation in δ13CR and the respiratory apparent fractionation, we measured the δ13CR, the leaf gas exchange, and the δ13C of the respiratory substrates of 22 species present in the agricultural-pastoral zone of the Songnen Plain, northeast China. The species studied were grouped into C3 and C4 plants, trees, grasses, and herbs. A significant nocturnal shift in δ13CR was detected in 20 of the studied species, with the magnitude of the shift ranging from 1‰ to 5.8‰. The magnitude of the nighttime variation in δ13CR was strongly correlated with the daytime cumulative carbon assimilation, which suggests that variation in δ13CR were influenced, to some extent, by changes in the contribution of malate decarboxylation to total respiratory CO2 flux. There were no differences in the magnitude of the nighttime variation in δ13CR between the C3 and C4 plants, as well as among the woody plants, herbs and graminoids. Leaf respired CO2 was enriched in 13C compared to biomass, soluble carbohydrates and lipids; however the magnitude of enrichment differed between 8 pm and 4 am, which were mainly caused by the changes in δ13CR. We also detected the plant functional type differences in respiratory apparent fractionation relative to biomass at 4 am, which suggests that caution should be exercised when using the δ13C of bulk leaf material as a proxy for the δ13C of leaf-respired CO2.

The regression tree method is used to upscale evapotranspiration (ET) measurements at eddy-covariance (EC) towers to the grassland ecosystems over the Dryland East Asia (DEA). The regression tree model was driven by satellite and meteorology datasets, and explained 82% and 76% of the variations of ET observations in the calibration and validation datasets, respectively. The annual ET estimates ranged from 222.6 to 269.1 mm yr(-1) over the DEA region with an average of 245.8 mm yr(-1) from 1982 through 2009. Ecosystem ET showed decreased trends over 61% of the DEA region during this period, especially in most regions of Mongolia and eastern Inner Mongolia due to decreased precipitation. The increased ET occurred primarily in the western and southern DEA region. Over the entire study area, water balance (the difference between precipitation and ecosystem ET) decreased substantially during the summer and growing season. Precipitation reduction was an important cause for the severe water deficits. The drying trend occurring in the grassland ecosystems of the DEA region can exert profound impacts on a variety of terrestrial ecosystem processes and functions.

Objective: To investigate the incidence and the gene mutation frequencies and patterns of α-thalassemia in preschool children in Chongqing city., Methods: Cluster random sampling was used. A total of 1057 preschool children in three areas of Chongqing were screened by using routine blood test and hemoglobin electrophoresis analysis. Molecular analysis carried out for all the samples., Results: Of the 1057 samples, 55 cases were diagnosed as being carriers of α-thalassemia, which included 80 allele genes. Therefore, the frequency of α-thalassemia carriers in Chongqing was 5.20%. Of the 55 α-thalassemia carriers, five different deletions of α-thalassemia were identified, the three most common deletion types and proportions were 54.55% for the -α(3.7) deletion, 18.18% for --(SEA) deletion, and 9.08% for the -α(4.2) deletion, respectively; eight types of nondeletion defects were determined, containing one case of Hb Quong Sze and seven novel mutations of a-globin gene. Furthermore, 24 cases of α-Triplication were detected with the α-Triplication carrier rate of 2.55%. In addition, in this study we also found two cases of abnormal hemoglobin disorders occurred on α-globin gene, Hb J-Wenchang-Wuming and Hb Arya. Hb Arya was characterized in the Chinese population for the first time confirmed by literature retrieval., Conclusion: In this study, we have clarified the carrier frequency and molecular spectrum of α-thalassemia in Chongqing, and we first reported the carrier incidence of α-Triplication in Chongqing. The materials obtained from this study would be of valuable reference for genetic counseling and the examination instruction of children in this area.

Background and Aims: Leaf longevity is an important plant functional trait that often varies with soil nitrogen supply. Ethylene is a classical plant hormone involved in the control of senescence and abscission, but its role in nitrogen-dependent leaf longevity is largely unknown., Methods: Pot and field experiments were performed to examine the effects of nitrogen addition on leaf longevity and ethylene production in two dominant plant species, Agropyron cristatum and Stipa krylovii, in a temperate steppe in northern China., Key Results: Nitrogen addition increased leaf ethylene production and nitrogen concentration but shortened leaf longevity; the addition of cobalt chloride, an ethylene biosynthesis inhibitor, reduced leaf nitrogen concentration and increased leaf longevity. Path analysis indicated that nitrogen addition reduced leaf longevity mainly through altering leaf ethylene production., Conclusions: These findings provide the first experimental evidence in support of the involvement of ethylene in nitrogen-induced decrease in leaf longevity.