Nutrient co‐limitation in the subtropical Northwest Pacific

Nutrients limiting phytoplankton growth in the ocean are a critical control on ocean productivity and can underpin predicted responses to climate change. The extensive western subtropical North Pacific is assumed to be under strong nitrogen limitation, but this is not well supported by experimental evidence. Here, we report the results of 14 factorial nitrogen–phosphorus–iron addition experiments through the Philippine Sea, which demonstrate a gradient from nitrogen limitation in the north to nitrogen–iron co-limitation in the south. While nitrogen limited sites responded weakly to nutrient supply, co-limited sites bloomed with up to ~60-fold increases in chlorophyll a biomass that was dominated by initially undetectable diatoms. The transition in limiting nutrients and phytoplankton growth capacity was driven by a gradient in deep water nutrient supply, which was undetectable in surface concentration fields. We hypothesize that this large-scale phytoplankton response gradient is both climate sensitive and potentially important for regulating the distribution of predatory fish

Molecular dynamics studies on the NMR and X-ray structures of rabbit prion protein wild-type and mutants

Prion diseases are invariably fatal and highly infectious neurodegenerative diseases that affect a wide variety of mammalian species such as sheep, goats, mice, humans, chimpanzees, hamsters, cattle, elks, deer, minks, cats, chicken, pigs, turtles, etc. These neurodegenerative diseases are caused by the conversion from a soluble normal cellular protein into insoluble abnormally folded infectious prions and the conversion is believed to involve conformational change from a predominantly alpha-helical protein to one rich in beta-sheet structure. Such conformational changes may be amenable to study by molecular dynamics (MD) techniques. For rabbits, classical studies show they have a low susceptibility to be infected, but in 2012 it was reported that rabbit prion can be generated (though not directly) and the rabbit prion is infectious and transmissible (Proceedings of the National Academy of Sciences USA 109(13): 5080-5). This paper studies the NMR and X-ray molecular structures of rabbit prion protein wild-type and mutants by MD techniques, in order to understand the specific mechanism of rabbit prion protein and rabbit prions.Comment: (The 2nd version of arXiv1304.7633

The Implementation of China's Mental Health Law-Defined Risk Criteria for Involuntary Admission: A National Cross-Sectional Study of Involuntarily Hospitalized Patients

Objective: Involuntary admission is one of the most controversial issues in psychiatry in China. This study aimed to examine the implementation of the new risk criteria for involuntary admission, as defined by the new Mental Health Law (MHL), in major psychiatric hospitals; and to explore factors associated with the implementation.Method: We selected 32 psychiatric hospitals in 29 provincial capital cities in mainland China. We included all involuntarily admitted psychiatric inpatients who were discharged from December 25 to 27, 2017. Patients' demographic and clinical data and reasons for admission were retrieved. Hospitals' information was also collected. Multilevel logistic regression was applied to explore factors associated with the implementation.Results: We collected valid data from 814 inpatients. Rates of risk criteria implementation ranged from 7.9 to 88.5% in these hospitals. Only 369 inpatients (45.3%) met the MHL-defined risk criteria. Overall, between 62.2 and 78.5% of the variance in risk criteria implementation was at the patient level, and between 21.5 and 37.8% of the variance was at the hospital level. Patients with higher Global Assessment of Functioning (GAF) scores at admission were less likely to meet the risk criteria (OR 1.02, 95% CI 1.01–1.03). No statistically significant association was found between risk criteria implementation and other patient level or hospital level factors.Conclusion: Our findings show the implementation rate of the MHL's risk criteria overall was low, with only 45.3% of involuntary admissions meeting the MHL-defined criteria. This suggests that some patients' civil rights might have been violated

Psychiatry Residents in China: Socio-Demographic Characteristics, Career Satisfaction, and Related Factors

Objective: To study the socio-demographic characteristics, the working environment, and the level of career satisfaction among psychiatry residents in China.Method: This was a part of a large-scale, nation-wide online survey of hospitals, healthcare professionals, and patients. Data, including socio-demographics, work hours, income, job satisfaction, and intention to quit were collected anonymously. Respondents also completed the Minnesota Satisfaction Questionnaire (MSQ).Results: One thousand sixty residents nested in 32 psychiatric hospitals in 29 provinces in China completed the survey. Respondents were predominantly female (69.0%), worked an average of 47.8 ± 11.6 h per week, and 28.97% had experienced medical disputes in the previous year. The top three reported reasons for dissatisfaction were low pay (50.1%), contentious doctor-patient relationships (17.6%), and high workload (10.8%). An intention to quit their current job was reported by 18.7% of residents. The overall mean MSQ score was 73.8 ± 13.8, with significant differences across post-graduate training years and regions. A multilevel regression analysis found that a higher MSQ score was significantly associated with fewer years in residency, shorter work hours, higher monthly pay, having medical liability insurance, and feeling satisfied with the level of doctor-nurse cooperation, their hospitals' medical disputes prevention/management, and the healthcare workers' social environment.Conclusion: Psychiatry residents in China are predominantly female and well-educated. They are only moderately satisfied with their career. Poor salaries, contentious doctor-patient relationships and high workload are among their top complaints and may explain why a considerable proportion are intending to leave their current residency. More support from the government regarding residents' salaries, workload and working environment may help improve their job satisfaction and retention, ensuring that China will have a pool of well-trained and engaged psychiatrists for the future

Evaluation of spatial-temporal variations and trends in surface water quality across a rural-suburban-urban interface

Water quality degradation is often a severe consequence of rapid economic expansion in developing countries. Methods to assess spatial-temporal patterns and trends in water quality are essential for guiding adaptive management efforts aimed at water quality remediation. Temporal and spatial patterns of surface water quality were investigated for 54 monitoring sites in the Wen-Rui Tang River watershed of eastern China to identify such patterns in water quality occurring across a rural-suburban-urban interface. Twenty physical and chemical water quality parameters were analyzed in surface waters collected once every 4-8 weeks from 2000 to 2010. Temporal and spatial variations among water quality parameters were assessed between seasons (wet/dry) and among major land use zones (urban/suburban/rural). Factor analysis was used to identify parameters that were important in assessing seasonal and spatial variations in water quality. Results revealed that parameters related to organic pollutants (dissolved oxygen (DO), chemical oxygen demand (manganese) (COD(Mn)), and 5-day biochemical oxygen demand (BOD₅)), nutrients (ammonia nitrogen (NH₄ ⁺-N), total nitrogen (TN), total phosphorus (TP)), and salt concentration (electrical conductivity (EC)) were the most important parameters contributing to water quality variation. Collectively, they explained 70.9 % of the total variance. A trend study using the seasonal Kendall test revealed reductions in COD(Mn), BOD₅, NH₄ ⁺-N, petrol, V-phen, and EC concentrations over the 11-year study period. Cluster analysis was employed to evaluate variation among 14 sampling sites representative of dominant land use categories and indicated three, three, and four clusters based on organic, nutrient, and salt water quality characteristics, respectively. Factors that are typically responsible for water quality degradation (including population, topography, and land use) showed no strong correlation with water quality trends implying considerable point source inputs in the watershed. The results of this study help inform ongoing water quality remediation efforts by documenting trends in water quality across various land use zones

Investigation of spinal dynamic stabilization device using finite element method

A FE model of lumbar spine was developed and validated, which was used to evaluate biomechanical effect of new dynamic stabilization device (FlexPLUS). The FlexPLUS system was more flexible than rigid rod system but not flexible enough to preserve motion and restore natural load sharing ability of the operated segment.MASTER OF ENGINEERING (MPE

Public Perception on Healthcare Services: Evidence from Social Media Platforms in China

Social media has been used as data resource in a growing number of health-related research. The objectives of this study were to identify content volume and sentiment polarity of social media records relevant to healthcare services in China. A list of the key words of healthcare services were used to extract data from WeChat and Qzone, between June 2017 and September 2017. The data were put into a corpus, where content analyses were performed using Tencent natural language processing (NLP). The final corpus contained approximately 29 million records. Records on patient safety were the most frequently mentioned topic (approximately 8.73 million, 30.1% of the corpus), with the contents on humanistic care having received the least social media references (0.43 Million, 1.5%). Sentiment analyses showed 36.1%, 16.4%, and 47.4% of positive, neutral, and negative emotions, respectively. The doctor-patient relationship category had the highest proportion of negative contents (74.9%), followed by service efficiency (59.5%), and nursing service (53.0%). Neutral disposition was found to be the highest (30.4%) in the contents on appointment-booking services. This study added evidence to the magnitude and direction of public perceptions on healthcare services in China’s hospital and pointed to the possibility of monitoring healthcare service improvement, using readily available data in social media