An assessment of the costs and benefits of interventions aimed at improving rural community water supplies in developed countries

We report a cost benefit analyses (CBA) for water interventions in rural populations of developed country sub-regions. A Bayesian belief network was used to estimate the cost benefit ratio using Monte Carlo simulation. Where possible we used input data from recently published primary research or systematic reviews. Otherwise variables were derived from previous work in the peer-reviewed or grey literature. For these analyses we considered the situation of people with small and very small community supplies that may not be adequately managed. For the three developed country sub-regions Amr-A (America region A), Eur-A (European region A) and Wpr-A (Western Pacific region A), we estimate the costs of acute diarrhoeal illness associated with small community supplies to be U$4671 million (95% CI 1721-9592), the capital costs of intervention to be US$13703 million (95% CI 6670-20735), additional annual maintenance to be US$804 million (95%CI 359-1247) and the CB ratio to be 2.78 (95%CI 0.86-6.5). However, we also estimated the cost of post infectious irritable bowel syndrome (IBS) following drinking water-associated acute gastroenteritis to be US$11896 million (95%CI 3118-22657). When the benefits of reduced IBS are added to the analysis the CB ratio increases to 9.87 (95%CI 3.34-20.49). The most important driver of uncertainty was the estimate of the cost of illness. However, there are very few good estimates of costs in improving management of small rural supplies in the literature.Investments in drinking-water provision in rural settings are highly cost beneficial in the developed world. In the developed world, the CB ratio is substantially positive especially once the impact of IBS is included.     

Eliciting patient preferences in today's health care system.

The American Medical Association Council on Ethical and Judicial Affairs recommends that physicians discuss advance directives with their patients and the patients' proxies. The council could have gone further by recognizing the difficulties physicians will encounter in trying to implement its proposal in a managed health care system. There is an undeniable need for caregiver participation in end-of-life planning, but the health care system must recognize and support implementation of the council's recommendations to make that possible. More explicit recognition of this fact on the part of the council would have helped physicians attempt to comply with its recommendations. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

A functional magnetic resonance imaging study of auditory vigilance with low and high information processing demands.

This study identified the brain activations associated with auditory vigilance tasks, using functional magnetic resonance imaging. We created auditory continuous performance tests (CPTs) in which a demanding task (working memory task) was made more difficult than a simple vigilance task by increasing working memory and interference filtering demands. Two cohorts of normal male controls performed significantly worse on the working memory CPT than on the vigilance task. Compared to the vigilance task, performance of the working memory task produced significant signal change in lateral and medial prefrontal cortex, precentral cortex, temporal lobe, including insula and hippocampus, parietal-occipital cortex, cingulate, thalamus, and superior colliculus. Performance and degree of activation was associated with an estimate of IQ. Further research should clarify the contributions of working memory and interference filtering to the activated network. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Glowing Graphene Quantum Dots and Carbon Dots: Properties,Syntheses, and Biological Applications

The emerging graphene quantum dots (GQDs) and carbon dots (C‐dots) have gained tremendous attention for their enormous potentials for biomedical applications, owing to their unique and tunable photoluminescence properties, exceptional physicochemical properties, high photostability, biocompatibility, and small size. This article aims to update the latest results in this rapidly evolving field and to provide critical insights to inspire more exciting developments. We comparatively review the properties and synthesis methods of these carbon nanodots and place emphasis on their biological (both fundamental and theranostic) applications.     

Highly Porous SiOC Bulk Ceramics with Water Vapor Assisted Pyrolysis

Micro/mesoporous SiOC bulk ceramics with the highest surface area and the narrowest pore size distribution were prepared by water‐assisted pyrolysis of polysiloxane in argon atmosphere at controlled temperatures (1100°C–1400°C) followed by etching in hydrofluoric acid (HF) solution. Their pyrolysis behaviors, phase compositions, and microstructures were investigated by DSC, FTIR, XRD, and BET. The Si–O–Si bonds, SiO₂‐rich clusters, and SiO₂ nanocrystals in the pyrolyzed products act as pore‐forming species and could be etched away by HF. Water injection time and pyrolysis temperature have important effects on phase compositions and microstructures of the porous SiOC bulk ceramics, which have a maximum‐specific surface area of 2391.60 m²/g and an average pore size of 2.87 nm. The porous SiOC ceramics consist of free carbon phase, silicon carbide, and silicon oxycarbide.     

如何成为一个专家

阻碍你从业余选手变成专家的唯一因素就是：专注。天才？如果我们投入足够的时间并足够专注，我们都可以一跃（至少接近）成为天才。至少大脑科学家们是这么说的。最棒的是——这样做从来都不晚。     

Compaction of different boron carbide powders using uniaxial die compaction and combustion driven compaction

Compaction of pure B₄C and Ni₂B nanolayer coated B₄C was studied using uniaxial die compaction and combustion driven compaction techniques. Effects of different compaction techniques and the Ni₂B nanolayer around B₄C particle surfaces on green B₄C sample characteristics are the focus of this study. The combustion driven compaction process yields much higher green density and strength than the uniaxial die compaction process. For the samples obtained from the same compaction technique, the Ni₂B nanolayer on individual B₄C particle surfaces improves the green density and strength of the B₄C powder compacts. For the combustion driven compaction process, optical images show micro-cracks on the surface of pure B₄C compact while crack-free surface is observed for Ni₂B nanolayer coated B₄C sample. Scanning electron microscopy analysis shows the same trend as the green density and strength measurements. Combustion driven compaction diagram for hard and brittle materials such as B₄C is discussed.