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Drylands, where the water supplies are scarce relative to the atmospheric moisture demands, occupy approximately half of the area of China. With global warming, the response of atmospheric water cycle is a crucial concern for sustainable development in China's drylands. This study investigates the characteristics of the water cycle in China's drylands during 1980–2019, as well as future projections estimated by the Community Earth System Model (CESM) during 2020–2100. The results show that the air temperature in China's drylands has increased significantly since 1980, especially after 2000, with greater warming in the warm season. Meanwhile, China generally tend to be drier from 1980 to 2019 as a whole, especially in the cold season. Both precipitation (P) and evapotranspiration (E) have increased, but the net effect is that drylands become drier (negative P-E) and wetlands become wetter (positive P-E), respectively. In the future, drylands are projected to become more humid due to increased precipitation, showing a pattern of "western wetter and eastern drier" during 2020–2100. These results could improve understanding of the water cycle and provide some guidance for adapting to climate change in drylands. [ABSTRACT FROM AUTHOR]

Previous research on national park conservation has predominantly concentrated on their internal regions, with scant attention given to the parks and their adjacent areas as integrated entities. Therefore, the investigation of land cover and landscape ecological risks in national parks and surrounding areas is essential for overall ecosystem protection and regional sustainable development. This study examines the spatiotemporal evolution of land cover and its landscape ecological risk in Wuyishan National Park, China, and its surrounding areas (WNPSA) from 1990 to 2020. The results show that (1) the land cover of WNPSA from 1990 to 2020 predominantly exhibited a consistent decline in forested areas, paralleled by an augmentation in farmland and impervious surface areas. The center of standard deviation ellipse of impervious surfaces has been progressively moving further south in tandem with the expansion of these surfaces, primarily located within the county town of Fujian Province. (2) The Wuyishan National Park (WNP) areas were dominated by low values of landscape index, and the high value areas in the park were mainly located at the provincial boundary area, with a gradual narrowing during 1990–2020, suggesting a decrease in landscape heterogeneity within the park. High value areas in the surrounding areas mainly occurred in areas with clustered impervious surfaces (e.g., the county town), where part of them located in Wuyishan City have spread to the edge area southeast of WNP. (3) From 1990 to 2020, the lowest-risk areas continue to expand. However, as the medium-risk zone of the adjacent region extends into the edge of the national park, the low risk zone within the national park exhibits a trend from continuous to separate with the neighboring low risk zone. This led to an escalating stress effect on the ecological security of both the adjacent regions and the national park's boundary areas due to land cover changes. [ABSTRACT FROM AUTHOR]

Water vapor plays an important role in the cloud precipitation process. In summer, the water vapor over North China is mainly delivered by westerlies and East Asian summer monsoon (EASM), but the former is often overlooked. In this study, using empirical orthogonal function analysis, we found that the summer precipitation as well as the water vapor transported by westerlies and the EASM showed substantial variability in North China during 1979–2019. Additionally, the corresponding principal component of water vapor transport is significantly correlated with the time series of precipitation, indicating the combined water vapor flux transported by westerlies and the EASM dramatically affects precipitation in North China. Further analysis revealed that the combined water vapor transport is driven by the circumglobal teleconnection pattern. Using numerical simulations, we quantified the relative effects of water vapor transported by westerlies and the EASM and explored the mechanisms involved. Sensitivity experiments demonstrated that with a 50% reduction in westerly-driven water vapor transport, the precipitation in North China will decrease by 19.59%, and if the water vapor transported by the EASM is likewise halved, the precipitation will decrease by 38.31%. Moreover, when the combined westerly and EASM-driven water vapor transport is reduced by 50%, the precipitation will decrease by 48.90%, which is more severe than the effect of reducing either water vapor transport individually. Therefore, the effect that the water vapor transported by westerlies has on precipitation in North China cannot be ignored and should be considered together with the water vapor transported by the EASM. [ABSTRACT FROM AUTHOR]

The Tibetan Plateau (TP), known as the "Third Pole," profoundly affects weather and climate at regional and global scales. In this study, we investigate the characteristics of heat waves in China and their association with the TP heat source. The results show that during the summertime from 1980 to 2020, the frequency of heat wave days that hit eastern China and northwest China increased at rates of 0.09 and 0.24 days yr−1, respectively, accompanied by an increase in the atmospheric heat source (AHS) over the TP by over 2 W m−2 yr−1 under the background of global warming. The enhanced TP heat source induces an anomalous upper-tropospheric anticyclone, which caused the western Pacific subtropical high and South Asia high to be stronger and closer to each other, causing descending motions over eastern China and consequently more heat waves. At the same time, the enhanced TP heat source weakened the westerlies, thereby favoring the occurrence and maintenance of the anticyclone centered in northwest China and creating more heat waves due to strong descending motions. Therefore, the association between the TP heat source and heat waves in China provides relevant information for studying the mechanism and future changes of heat waves. Significance Statement: The Tibetan Plateau significantly affects the surrounding weather and climate. We find that there are some linkages between the Tibetan heat source and heat waves in China. The stronger the Tibetan heat source is, the more heat waves hit China. The enhancement of the Tibetan heat source could induce an anomalous upper-tropospheric anticyclone by affecting the western Pacific subtropical high and South Asia high, consequently causing descending motions over eastern China and the resulting heat waves. The weaker westerly due to the enhanced Tibetan heat source favors the occurrence of the anticyclone centered in northwest China, leading to more heat waves by descending motions. This study reveals a potential contributor to heat waves in China, providing some clues for better prediction in the future. [ABSTRACT FROM AUTHOR]

In this study, the long-term characteristics of the dust weather frequency (DWF) in the ensuing spring (March–April–May, MAM) in northern China (NC) and the association with sea ice concentration in the Barents Sea (SICBS) and Arctic Oscillation (AO) in the preceding winter (December–January–February, DJF) during 1979–2021 are investigated. The results show that the dust weather in NC is mainly associated with decreased SICBS during 1982–2008 and linked with a negative AO phase during 2009–2021. Due to the decreased SICBS in the preceding winter during 1982–2008, the surface adiabatic heating excites Rossby waves to spread southward and eastward, resulting in decreased snow cover over Eurasia and more dust weather by anomalous northerly wind in the ensuing spring over NC. On the other hand, with a negative AO phase in the preceding winter during 2009–2021, the increased meridional temperature gradient at mid-latitudes tends to enhance westerly wind and cyclogenesis over NC, leading to more dust weather in the ensuing spring. Consequently, both the negative AO phase and decreased SICBS in the preceding winter correspond to strong wind and dry soil in the dust source region, which favor an increase in the DWF in the ensuing spring over NC. Studying the characteristics of the SICBS and AO could provide some clues to predict the dust weather in NC. [ABSTRACT FROM AUTHOR]

Dust direct radiative effect (DDRE) can modify the near‐surface air temperature, which can in turn influence dust emission. However, the feedback mechanism of DDRE on dust emission is poorly understood. In this study, the influence of DDRE on dust emission in Taklimakan Desert (TD) was investigated using comprehensive ground‐based observations. The results show that the near‐surface air temperature significantly decreased as a result of DDRE, corresponding to dust emission enhanced. Statistically, the contributions of DDRE to dust emission during light, moderate, and heavy dusty episodes were 5.0% (3.6%), 5.2% (2.8%), and 6.1% (3.3%) in spring (summer), respectively. From the perspective of mechanism, DDRE can induce an increase in air density by cooling the near‐surface, causing an enhancement of aerodynamic drag, promoting dust emission in TD. Such positive feedback of DDRE on dust emission may be a potential contributor to improving the dust emission scheme of numerical modeling in the future. Plain Language Summary: Taklimakan Desert (TD) is a significant dust source in China and East Asia, providing abundant dust aerosols that are suspended in the atmosphere over Tarim Basin. Currently, the feedback mechanism of the radiative effect of suspended dust on dust emission is poorly understood. By combining comprehensive ground‐based observations with reanalysis data, we investigated the influence of dust direct radiative effect (DDRE) on dust emission in TD. Due to the DDRE, the near‐surface air temperature during light, moderate and heavy dust pollution episodes decreased by 7.01 (4.38), 7.28 (3.51), and 8.50 K (4.06 K) in spring (summer), respectively. Such a distinct cooling effect decreased the threshold wind speed, leading to dust emission enhanced in TD. The contributions of DDRE to dust emission were 5.0%–6.1% (2.8%–3.6%) in spring (summer). According to the physical mechanism of sand movement, the near‐surface cooling effect caused by DDER induced an increase in air density, leading to the enhancement of aerodynamic drag, which resulted in more dust particles leaving from the surface. Therefore, DDER is responsible for the promotion of dust emissions in TD. The results are beneficial for improving dust emission schemes in future modeling. Key Points: Dust direct radiative effect (DDRE) and air pressure are presented as quadratic functionsContributions of DDRE to dust emission are 5.0%–6.1% (2.8%–3.6%) in spring (summer)Enhancement of aerodynamic drag is the primary cause of dust emission increased [ABSTRACT FROM AUTHOR]

The Tibetan Plateau (TP), the so-called water tower of Asia, plays an important role in the water cycle. However, few studies have linked the TP's water vapor supply with the climate over North China. In this study, we found that changes in the subtropical westerly jet (SWJ) dynamically induce drought in North China, and the TP plays an important role in this relationship. During July–August for the period of 1981–2019, the SWJ center between 75° and 105°E obviously shifted northward at a rate of 0.04° per year. Correspondingly, the zonal winds in the southern subtropics were incredibly weakened, causing the outflow of water vapor from the TP to decrease dramatically. Combined with numerical simulations, we discovered that a reduction in water vapor transport from the TP can obviously decrease the precipitation over North China. Sensitivity experiments demonstrated that if the water vapor outflow from the eastern border of the TP decreases by 52.74%, the precipitation in North China will decrease by 12.69% due to a decrease in the local cloud fraction caused by a diminished water vapor content in the atmosphere. Therefore, although less water vapor transport occurs in the upper troposphere than in the lower troposphere, the impact of transport from the TP in the former on the downstream precipitation cannot be ignored. [ABSTRACT FROM AUTHOR]

Copyright of Advances in Atmospheric Sciences is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Based on satellite observations and reanalysis datasets, this study focuses on the effect of aerosols on clouds over the Tibetan Plateau (TP) and the impact of dust-polluted convective clouds on precipitation over downstream regions. A heavy dust event is detected by Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) over the northern slope of the TP on 16 July and 17 July 2016. The high aerosol optical depth (AOD) values are mainly distributed over the northern slope of the TP. Simultaneously, the CloudSat satellite observes deep convective clouds over the northern slope area of the TP, in which convective clouds and dust mix at the same height. With the AOD increasing from 16 July to its peak on 17 July, the ice particle size decreases to a minimum, and convective clouds develop at higher heights because of the prolonged cloud life. Accordingly, a larger ice water path (IWP) is induced by the development of convective clouds that move eastwardly from 16 to 17 July. In the following days, under favorable meteorological conditions, some of the developed convective clouds continuously move eastward and merge with the convective cloud clusters along the motion path, which induces significant precipitation over the Yangtze River basin on 17 July. Furthermore, driven by the northward wind, some developed convective cloud clusters move northward and induce strong precipitation over North China on 19 July. The indirect effect of dust aerosols over the TP could enhance the plateau's cloud development and potentially contribute to downstream precipitation, which is a meaningful factor for weather forecasting. • This study focuses on the effect of aerosols on clouds over the TP. • The impact of dust-polluted convective clouds on precipitation over downstream regions is analyzed. • The indirect effect of dust aerosols on cloud over the TP, which is a meaningful factor for weather forecasting. [ABSTRACT FROM AUTHOR]

Dust aerosols have been generally regarded as efficient ice nuclei (IN), but their influences on mixed-phase clouds and precipitation are poorly quantified. In this study, combining satellite observations, reanalysis data and the Weather Research and Forecasting (WRF) model, we investigate the impacts of dust aerosols on mixed-phase clouds and precipitation during a super dust storm over northern China. The Suomi National Polar-Orbiting Partnership (S-NPP) satellite observed a super dust storm from March 15–19, 2021 in northern China, followed by heavy precipitation between March 17 and 19. The results showed that the occurrence of super dust storms may play an important role in cloud formation and precipitation processes. Furthermore, numerical modeling revealed that dust aerosols can increase the ice crystal number concentration (QN i) and decrease the cloud droplet number concentration (QN c) in mixed-phase clouds through the Wegener–Bergeron–Findeisen (WBF) process, in which the maximum increase in QN i can reach 21%. Simultaneously, the mass mixing ratios of rain, graupel and snow increased due to dust aerosols. Consequently, precipitation could increase by up to 9.8% in northern China. This study could provide evidence for understanding the mechanisms of dust effects on mixed-phase clouds over northern China. Time series of the domain–averaged (a) dust AOD (black) and cloud fraction (red), (b) liquid/ice water path (black/blue, unit: g·m−2) and cloud optical depth (red) over the study region from 15–19 March. The dust AOD and cloud parameters are derived from MERRA-2 and CERES products, respectively. (c) Effects of dust on precipitation, QN c , QN i , RE c and RE i from 17 to 19 March 2021 derived from model simulations (units: %). [Display omitted] • The occurrence of heavy dust storms may play an important role in cloud formation and precipitation processes. • Dust aerosols can enhance rainfall by increasing the number of ice crystals in mixed-phase clouds. • Dust aerosols can induce a maximum increase in the daily precipitation up to 9.8%. [ABSTRACT FROM AUTHOR]

ABSTRACT As the recent global warming hiatus has attracted worldwide attention, we examined the robustness of the warming hiatus in China and the related dynamical mechanisms in this study. Based on the results confirmed by the multiple data and trend analysis methods, we found that the annual mean temperature in China had a cooling trend during the recent global warming hiatus period, which suggested a robust warming hiatus in China. The warming hiatus in China was dominated by the cooling trend in the cold season, which was mainly induced by the more frequent and enhanced extreme-cold events. By examining the variability of the temperature over different time scales, we found the recent warming hiatus was mainly associated with a downward change of decadal variability, which counteracted the background warming trend. Decadal variability was also much greater in the cold season than in the warm season, and also contributed the most to the previous accelerated warming. We found that the previous accelerated warming and the recent warming hiatus, and the decadal variability of temperature in China were connected to changes in atmospheric circulation. There were opposite circulation changes during these two periods. The westerly winds from the low to the high troposphere over the north of China all enhanced during the previous accelerated warming period, while it weakened during the recent hiatus. The enhanced westerly winds suppressed the invasion of cold air from the Arctic and vice versa. Less frequent atmospheric blocking during the accelerated warming period and more frequent blocking during the recent warming hiatus confirmed this hypothesis. Furthermore, variation in the Siberian High and East Asian winter monsoon season supports the given conclusions. [ABSTRACT FROM AUTHOR]

Objectives To explore associations of BMI and waist circumference (WC) with disability among the Chinese oldest old. Methods The 5,495 oldest old in the sixth wave of Chinese Longitudinal Healthy Longevity Study conducted in 2011 were included in this study. Disability was assessed by activities of daily living (ADL); height and weight for BMI and WC were measured; information including socio-demographics, lifestyles, and health status was collected. Results Generalized additive models analysis showed that the association of BMI/WC with ADL disability was nonlinear. Among the males, logistic regression results supported a 'J' shape association between ADL disability with BMI/WC-the highest tertile group in BMI or WC was significantly associated with an increased risk of ADL disability: odds ratio 1.78 (95% confidence interval (CI): 1.26-2.52) for BMI and 2.01 (95% CI: 1.44-2.82) for WC. Among females, an inverse 'J' shape association was found, only the lowest tertile group before the cutoff point had an increased risk of ADL disability: odds ratio 1.42 (95%CI: 1.02-1.97) for BMI and 1.47 (95% CI:1.06-2.04) for WC. Conclusions Associations of BMI and WC with ADL disability are significant even in the oldest old, but differ between the genders. [ABSTRACT FROM AUTHOR]

Presents a study which focused on gender differentials of the oldest old persons in China. Data sources and methods; Demographic and socioeconomic status; Activities of daily living; Physical performance and cognitive function; Life satisfaction.

Copyright of Population & Development Review is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Polycyclic aromatic hydrocarbons (PAHs) and nitro-PAHs (NPAHs) in PM 2.5 were first observed at a background site (Yuzhong site: YZ site) in the northwestern highlands of China in five seasonal campaigns. Compared with major northwestern cities, PAHs and NPAHs at the YZ site were at a lower level but showed consistent seasonal differences. The PAH and NPAH concentrations peaked in the winter campaigns, which were 36.11 ± 6.54 ng/m3 and 418.11 ± 123.55 pg/m3, respectively, in winter campaign 1 and 28.97 ± 10.07 ng/m3 and 226.89 ± 133.54 pg/m3, respectively, in winter campaign 2. These values were approximately a dozen times larger those in other campaigns. The diagnostic ratios indicate that vehicle emissions were the primary source of the PAHs throughout the five campaigns, and coal and biomass combustion also contributed during the winter, summer, and fall campaigns. Among NPAHs, 2-nitrofluoranthene and 2-nitropyrene were generated through OH radical-initiated reactions during atmospheric transport, while 1-nitropyrene came from combustion sources. There is an observation worth pondering, which is that the ratio between pyrene and fluoranthene increased abnormally in the spring and fall campaigns, which is presumably caused by the burning of Tibetan barley straw in the northwestern highlands. The backward trajectories over Tibetan areas in Qinghai and southwestern Gansu are consistent with this hypothesis. In addition, this study reported for the first time that the burning of Tibetan barley straw has become a seasonal contributor to air pollution in northwestern China and is participating in the atmospheric transport of air pollutants driven by the monsoon in East Asia, which urgently requires further research. Image 1 • PAHs and NPAHs were first observed at SACOL in the northwestern highlands of China. • The ratio of Pyr to FR was unusually high in spring and fall sampling campaigns. • The high Pyr to FR ratio may be due to the burning of Tibetan barley straw. • Air pollution with Tibetan features produced an impact on the surrounding areas. It is first reported that the unique emission source in the northwestern highlands of China affects the atmospheric transport network of air pollutants in East Asia. [ABSTRACT FROM AUTHOR]

Clouds play a critical role in adjusting the global radiation budget and hydrological cycle; however, obtaining accurate information on the cloud base height (CBH) is still challenging. In this study, based on Lidar and aircraft soundings, we investigated the features of the CBH and determined the thresholds of the environmental relative humidity (RH) corresponding to the observed CBHs over Southeast China from October 2017 to September 2018. During the observational period, the CBHs detected by Lidar/aircraft were commonly higher in cold months and lower in warm months; in the latter, 75.91% of the CBHs were below 2000 m. Overall, the RHs at the cloud base were mainly distributed between 70 and 90% for the clouds lower than 1000 m, in which the most concentrated RH was approximately 80%. In addition, for the clouds with a cloud base higher than 1000 m, the RH thresholds decreased dramatically with increasing CBH, where the RH thresholds at cloud bases higher than 2000 m could be lower than 60%. On average, the RH thresholds for determining the CBHs were the highest (72.39%) and lowest (63.56%) in the summer and winter, respectively, over Southeast China. Therefore, to determine the CBH, a specific threshold of RH is needed. Although the time period covered by the collected CBH data from Lidar/aircraft is short, the above analyses can provide some verification and evidence for using the RH threshold to determine the CBH. [ABSTRACT FROM AUTHOR]

Objectives: Human epidermal growth factor receptor 2 (HER2)-targeted therapies have demonstrated potential benefits for metastatic colorectal cancer (mCRC) patients with HER2 amplification, but are not satisfactory in cases of HER2 mutant CRCs., Methods: Consequently, further elucidation of amplifications and somatic mutations in erythroblastic oncogene B-2 (ERBB2) is imperative. Comprehensive genomic profiling was conducted on 2454 Chinese CRC cases to evaluate genomic alterations in 733 cancer-related genes, tumor mutational burden, microsatellite instability, and programmed death ligand 1 (PD-L1) expression., Results: Among 2454 CRC patients, 85 cases (3.46%) exhibited ERBB2 amplification, and 55 cases (2.24%) carried ERBB2 mutation. p.R678Q (28%), p.V8421 (24%), and p.S310F/Y (12%) were the most prevalent of the 16 detected mutation sites. In comparison to the ERBB2 altered (alt) group, KRAS/BRAF mutations were more prevalent in ERBB2 wild-type (wt) samples (ERBB2wt vs . ERBB2alt, KRAS: 50.9% vs . 25.6%, p < 0.05; BRAF: 8.5% vs . 2.3%, p < 0.05). 32.7% (18/55) of CRCs with ERBB2 mutation exhibited microsatellite instability high (MSI-H), while no cases with HER2 amplification displayed MSI-H. Mutant genes varied between ERBB2 copy number variation (CNV) and ERBB2 single nucleotide variant (SNV); TP53 alterations tended to co-occur with ERBB2 amplification (92.3%) as opposed to ERBB2 mutation (58.3%). KRAS and PIK3CA alterations were more prevalent in ERBB2 SNV cases (KRAS/PIK3CA: 45.8%/31.2%) compared to ERBB2 amplification cases (KRAS/PIK3CA: 14.1%/7.7%)., Conclusion: Our study delineates the landscape of HER2 alterations in a large-scale cohort of CRC patients from China. These findings enhance our understanding of the molecular features of Chinese CRC patients and offer valuable implications for further investigation., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2024 The Authors.)

Due to its tremendous volume and severe environmental concern, sewage sludge (SS) management and treatment are significant in China. The recent prohibition (June 2021) of reusing SS as organic fertilizers makes it urgent to develop alternative processes. However, there is currently little research analyzing the applicability of using HP for sewage SS treatment in China. The significant difference in SS composition and the much less land supply in urban areas might invalidate most previous localized suggestions. In this paper, the development of emerging hydrothermal processes (HPs) for SS treatment will be reviewed, focusing on their decomposition mechanisms and the benefits of HPs compared with current SS treatment technologies. The SS volume, composition, and regulatory regime in China will also be evaluated. Those efforts could address the potential SS treatment capacity shortage and provide an opportunity to recover nutrients, organics and energy embedded in SS. The results show that HPs' high investment cost is mainly limited by the process scale, while their operating costs are comparable to incineration. Minimizing equipment erosion, ensuring process safety, and designing a more efficient heat recovery system are recommended for the future commercialization of HPs in China., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Atmospheric aerosols play an important role in affecting clouds and precipitation by serving as condensation/ice nuclei. However, how to quantify the contribution of anthropogenic aerosols to the alteration of clouds and precipitation remains unknown. In this study, using a Weather Research and Forecasting-Chemistry (WRF-Chem) model, we quantified the impacts of anthropogenic aerosols on cloud water properties under different precipitation grades during a single rainfall event over eastern China. The results of this study show that anthropogenic aerosols have varying effects on hourly precipitation with heavy (greater than 1.04 mm/h), moderate (0.41-1.04 mm/h), and light (less than 0.41 mm/h) grades. Due to the presence of anthropogenic aerosols, heavy precipitation is intensified by 70.96%; however, moderate and light precipitation is further weakened by 24.87% and 86.43%, respectively. For heavy precipitation, the addition of anthropogenic aerosols induces an enhancement in upward motion, increases the cloud water path and effective radius through the aerosol-radiation interaction (ARI) effect, which is the main reason for the intensification of heavy-grade precipitation. In addition, the weakened upward motion and decreased ice water path caused by ARI and aerosol-cloud interaction (ACI) effects play common roles in reducing moderate and light precipitation. Studying anthropogenic aerosols' impacts on precipitation is of great importance for understanding the influence of anthropogenic pollution on the weather and climate and even for promoting precipitation forecasting and prediction., Competing Interests: Declaration of competing interest No conflict of interest exits in the submission of this manuscript, and manuscript is approved by all authors for publication., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Background: Studies suggest that sleep quality and duration are significantly associated with mortality risk and health conditions, yet such studies are seldom conducted among very old adults. The objective of this study was to examine associations between self-reported sleep quality/duration and subsequent mortality/health among very old adults in China. A second objective determines whether these associations vary by age and gender., Methods: This study used data of the 2005 and 2008 waves from a large, representative survey with a total of 12,671 individuals in 22 provinces in mainland China, in which 3158 respondents were aged 90-99 and 2293 were centenarians. Two self-reported questions about sleep quality and duration were examined while adjusting for numerous socio-demographic, family/social support, health practices, and baseline health factors., Results: Hazard regressions showed that, when demographic factors are controlled for, Chinese elders who report poor and fair quality of sleep have 26% and 10% higher risk of death over the next three years compared to those with good sleep quality; those who sleep either 6h or less or 10h or more per day have an 18-22% higher mortality risk as compared to those who sleep 8h per day. The increased mortality risks of poorer sleep and too short or too long sleep duration are larger in men than in women and more robust in the oldest-old than in young elders. Logistic regressions show that poor sleep and daily sleep durations of 5h or less or 10h or more are also associated with worse health three years later., Conclusions: Poorer sleep quality and too short or too long sleep duration are associated with higher subsequent mortality risk and lower odds of being in a healthy state among very old Chinese., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Objectives: This study investigates the factors associated with frailty and the association of frailty with mortality in a national sample of adults aged 65-109 in China., Methods: Using the 2002 wave of the Chinese Longitudinal Healthy Longevity Survey, we construct a frailty index (FI) based on 39 measures available in the data set. We use ordinal logistic regressions to examine the factors associated with the FI and use Weibull hazard regression to examine the association between frailty and 3-year mortality from 2002 to 2005., Results: Age, sex, ethnicity, urban-rural residence, economic condition, religious involvement, and daily exercise are significantly associated with levels of frailty. Hazard analyses further reveal that the FI is a robust predictor of mortality at advanced ages and that the relationship between frailty and mortality is independent of various covariates. Discussion The measurement and analysis of frailty have broad implications for public health initiatives designed to target individuals with the diminished capacity to effectively compensate for external stressors and to prevent further declines associated with aging and mortality. A key to healthy longevity is the prevention, postponement, and potential recovery from physical and cognitive deficits at advanced ages through enhanced medical interventions and treatments.

Objective: This study investigates the role of customary activities, both social and solitary, in mortality among the oldest old in China., Methods: The data come from the Chinese Longitudinal Healthy Longevity Survey. Weibull hazard models analyze the mortality risk of those 80 years of age and older within a 2-year period between 1998 and 2000., Results: Results show that solitary activities, either active or sedentary, are significantly associated with lower mortality risk. The effect of social activities on mortality gradually diminishes with age and is reversed at very old ages when physical exercise, health status, and sociodemographic characteristics are controlled., Discussion: Customary activities, which are less physically demanding, show independent effects on the elderly's survival. Withdrawal from social contacts may be an adaptive response to challenges faced at very advanced ages. It is important to recognize the unique characteristics of this rapidly growing population.