Career preferences of graduating medical students in China: a nationwide cross-sectional study

Background: China faces major challenges in the distribution of health professionals with serious shortages in rural areas and in the development of Primary Care Providers (PCPs). This study investigates the career preferences of medical students in China and the impact of rural backgrounds on these preferences. Methods: Medical students in the final year of their program in 16 medical schools across China completed a 58-item survey that included questions regarding their demographic characteristics, attitudes toward practice in low resource areas, postgraduate planning, self-assessed competency, university facilities assessment, and financial situation. Descriptive calculation and Logit model were used for the analysis. Results: Completed surveys from 3020 students were included in the analysis. Upon graduation, 48.5 % of the medical students preferred to work in urban public hospitals and this percentage rose to 73.6 % when students were asked to state their anticipated preference five years after graduation. Students' top three ranked reasons for preferred careers were "good career prospects", "living close to parents/families", and "remuneration". Those who preferred to work in rural areas upon graduation were more likely to be those who lived in rural areas when 1-15 years old (beta = 2.05, p < 0.001), had high school in rural areas (beta = 1.73, p < 0.001), or had parents' place of current residence in rural areas (beta = 2.12, p < 0.001). Similar results were found for those students who preferred to work in PCPs. Conclusions: To address the serious shortages of health professionals in rural areas and PCPs, medical schools should consider strategies to recruit more medical applicants with rural backgrounds and to orient students to rural and primary care interests.SCI(E)[email protected]

A new global river network database for macroscale hydrologic modeling

Coarse-resolution (upscaled) river networks are critical inputs for runoff routing in macroscale hydrologic models. Recently, Wu et al. (2011) developed a hierarchical dominant river tracing (DRT) algorithm for automated extraction and spatial upscaling of river networks using fine-scale hydrography inputs. We applied the DRT algorithms using combined HydroSHEDS and HYDRO1k global fine-scale hydrography inputs and produced a new series of upscaled global river network data at multiple (1/16° to 2°) spatial resolutions. The new upscaled results are internally consistent and congruent with the baseline fine-scale inputs and should facilitate improved regional to global scale hydrologic simulations

Sodium reduction: how big might the risks and benefits be?

Cardiovascular diseases are the leading cause of death worldwide and raised blood pressure is the leading risk for these conditions. Excess sodium intake clearly elevates blood pressure though the association of sodium intake with cardiovascular outcomes has been disputed. Nonetheless, it was estimated that in 2017 excess dietary sodium caused between 1.4 and 5.4 million deaths. Key underlying assumptions for those estimates were that the association between sodium intake and cardiovascular disease is direct and linear, and that a daily consumption level of 2.0 g of sodium minimised risk. Recent data indicating that reported U-shaped associations of sodium with risk are the result of confounding provide strong support for the first assumption. Cardiovascular risks may, however, continue to decline below intake levels of 2.0 g per day. Further, because excess sodium intake appears to drive a progressive rise in blood pressure with age, the magnitude of the disease burden avoidable by sodium reduction may have been under-estimated. Regardless, health benefits will only be achieved if safe, effective and scalable interventions can be defined and none have been identified to date. Salt substitution, which switches regular salt for a reduced-sodium, added-potassium alternative offers a significant opportunity. Falls in blood pressure with salt substitution are comparable to single-drug therapy and salt substitutes are low cost, simple to use, well-tolerated and could be applied community-wide. Data that prove clinical benefits and exclude risks will be required to support widespread use. An ongoing large-scale randomised trial of the effects of salt substitution on stroke, major cardiovascular events and death will complete soon and define the role of salt substitutes in public health

The critical role of the routing scheme in simulating peak river discharge in global hydrological models

Global hydrological models (GHMs) have been applied to assess global flood hazards, but their capacity to capture the timing and amplitude of peak river discharge—which is crucial in flood simulations—has traditionally not been the focus of examination. Here we evaluate to what degree the choice of river routing scheme affects simulations of peak discharge and may help to provide better agreement with observations. To this end we use runoff and discharge simulations of nine GHMs forced by observational climate data (1971–2010) within the ISIMIP2a project. The runoff simulations were used as input for the global river routing model CaMa-Flood. The simulated daily discharge was compared to the discharge generated by each GHM using its native river routing scheme. For each GHM both versions of simulated discharge were compared to monthly and daily discharge observations from 1701 GRDC stations as a benchmark. CaMa-Flood routing shows a general reduction of peak river discharge and a delay of about two to three weeks in its occurrence, likely induced by the buffering capacity of floodplain reservoirs. For a majority of river basins, discharge produced by CaMa-Flood resulted in a better agreement with observations. In particular, maximum daily discharge was adjusted, with a multi-model averaged reduction in bias over about 2/3 of the analysed basin area. The increase in agreement was obtained in both managed and near-natural basins. Overall, this study demonstrates the importance of routing scheme choice in peak discharge simulation, where CaMa-Flood routing accounts for floodplain storage and backwater effects that are not represented in most GHMs. Our study provides important hints that an explicit parameterisation of these processes may be essential in future impact studies

Airborne observations reveal elevational gradient in tropical forest isoprene emissions

Isoprene dominates global non-methane volatile organic compound emissions, and impacts tropospheric chemistry by influencing oxidants and aerosols. Isoprene emission rates vary over several orders of magnitude for different plants, and characterizing this immense biological chemodiversity is a challenge for estimating isoprene emission from tropical forests. Here we present the isoprene emission estimates from aircraft eddy covariance measurements over the Amazonian forest. We report isoprene emission rates that are three times higher than satellite top-down estimates and 35% higher than model predictions. The results reveal strong correlations between observed isoprene emission rates and terrain elevations, which are confirmed by similar correlations between satellite-derived isoprene emissions and terrain elevations. We propose that the elevational gradient in the Amazonian forest isoprene emission capacity is determined by plant species distributions and can substantially explain isoprene emission variability in tropical forests, and use a model to demonstrate the resulting impacts on regional air quality

2016 International Land Model Benchmarking (ILAMB) Workshop Report

As earth system models (ESMs) become increasingly complex, there is a growing need for comprehensive and multi-faceted evaluation of model projections. To advance understanding of terrestrial biogeochemical processes and their interactions with hydrology and climate under conditions of increasing atmospheric carbon dioxide, new analysis methods are required that use observations to constrain model predictions, inform model development, and identify needed measurements and field experiments. Better representations of biogeochemistryclimate feedbacks and ecosystem processes in these models are essential for reducing the acknowledged substantial uncertainties in 21st century climate change projections