Author Correction: Emerging trends in global freshwater availability.

In Fig. 2 of this Analysis, the tick-mark labels on the colour bars in the second and third images from the top were inadvertently swapped. In addition, the citation at the end of the sentence, "On a monthly basis GRACE can resolve TWS changes with sufficient accuracy over scales that range from approximately 200,000 km2 at low latitudes to about 90,000 km2 near the poles" should be to ref. 4 not ref. 1. These errors have been corrected online.

Emerging trends in global freshwater availability.

Freshwater availability is changing worldwide. Here we quantify 34 trends in terrestrial water storage observed by the Gravity Recovery and Climate Experiment (GRACE) satellites during 2002-2016 and categorize their drivers as natural interannual variability, unsustainable groundwater consumption, climate change or combinations thereof. Several of these trends had been lacking thorough investigation and attribution, including massive changes in northwestern China and the Okavango Delta. Others are consistent with climate model predictions. This observation-based assessment of how the world's water landscape is responding to human impacts and climate variations provides a blueprint for evaluating and predicting emerging threats to water and food security.

How might recharge change under projected climate change in western US?

Although groundwater is a major resource of water in the western US, little research has been done on the impacts of climate change on groundwater storage and recharge in the West. Here we assess the impact of projected changes in climate on groundwater recharge in the near (2021-2050) and far (2071-2100) future across the western US. Recharge is expected to decrease slightly (highly certain) in the West (-1.6%) and Southwest (-2.9%) regions in the near future and decrease considerably (highly certain) in the South region (-10.6%) in the far future. The Northern Rockies region is expected to get more recharge (highly certain) in both the near (+5.0%) and far (+9.0%) future. In general, southern portions of the western US are expected to get less recharge in the future and northern portions will get more. This study also shows that climate change interacts with land surface properties to affect the amount of recharge that occurs in the future.

Collection of source material from remunerated donors.

The collection of plasma for further manufacture into medicinal products and in vitro diagnostic reagents is predominantly accomplished in the USA through the remuneration of donors who participate in plasmapheresis programmes. A well regulated system under the control of the Food and Drug Administration has been in place since the mid-1970s. Requirements of this regulatory system with regard to the need for donor acceptance and frequency of participation criteria, and plasma acceptability standards are reviewed. Information regarding several groups of donors participating in plasmapheresis procedures at various frequency intervals over 10 years is presented. Data on microhaematocrit, body weight, total protein, and individual serum protein distribution have been compiled and statistically analysed; the results of these analyses are included. Given the existence of a comprehensive approach which encompasses donor safety, plasma testing, and effective manufacturing procedures, safe and efficacious plasma derivatives can be produced from plasma drawn from remunerated donors and can be made available in sufficient quantity to meet medical needs in an economic manner.

Determination of reasons for cessation of participation in serial plasmapheresis programs.

BACKGROUND: An earlier retrospective review of records of over 500 remunerated donors participating in plasmapheresis programs at various levels of frequency for 10 or more years showed that there were no significant differences in mean values for total protein, microhematocrit, body weight, and individual serum proteins, regardless of the number of annualized donations for each of four frequency groups. Although these data demonstrated that donors undergoing serial plasmapheresis for 10 or more years were able to successfully continue in such programs, the review did not include information relative to individuals who had discontinued their participation. The current study investigated reasons that donors drop out of plasmapheresis programs. STUDY DESIGN AND METHODS: Donors who had successfully undergone plasmapheresis at least 20 times within a recent 6-month period but who had failed to appear for at least 30 days subsequent to their last donation were defined as potential subjects for the study. Staff members at the participating center contacted the donors, inviting them to return to the center to participate in a survey. Donors were also asked for a blood sample upon their arrival at the plasma center; samples were tested for total and various serum proteins. RESULTS: A total of 409 eligible subjects appeared at the centers for the survey, and 375 blood samples were analyzed for proteins. Survey responses indicated that the predominant reasons for an end to participation were socioeconomic in nature. Serum protein findings were compared to the most recent results obtained while the donors were active in the plasmapheresis program. Slightly higher mean serum protein findings were seen for samples collected on the survey date. CONCLUSION: A review of the aggregate responses obtained in the survey indicates that the predominant reasons that donors ceased to participate were not health-related: the remuneration was no longer needed, and work schedule conflicts, time constraints, and relocation were frequently cited.

Improving drug prescribing in a primary care practice.

A model for improving physician prescribing that utilizes computerized feedback was studied in a family medicine residency practice. Resident and faculty physicians were stratified by level of experience and randomized into two groups. For 9 months the experimental group received monthly printouts identifying drugs they had prescribed by brand name with estimates of cost savings that might have been realized by prescribing generic drugs. The control group received no feedback. Prescription monitoring of both groups continued for 12 months after all feedback had ceased. Median weighted rates of generic prescribing for the experimental physicians were 14% for the baseline, 67% for the feedback, and 54% for the follow-up periods. Rates for the control physicians for the three periods were 32%, 37% and 31%, respectively. The increase in generic prescribing by physicians in the experimental group was significantly greater than for control physicians (P = 0.01). The feedback model improved rates of generic prescribing but should be evaluated for broader areas of physician prescribing.