Rangeland Fires and Cheatgrass: Values at Risk and Support for Preservation

The high desert sagebrush ecosystems of the Great Basin evolved with fire. However, the introduction of cheatgrass (t. bromus), a highly flammable invasive annual grass, has contributed to the increased intensity and frequency of wildfires we have seen in recent years. Cheatgrass-fueled fires often kill native perennials, which creates openings for further cheatgrass expansion. Winters with more moisture than usual result in more cheatgrass and increased fire risk. Over time the result is ever larger areas dominated by cheatgrass and other invasive weeds that burn with greater frequency, and increasingly severe fire seasons

Rapid testing may not improve uptake of HIV testing and same day results in a rural South African community: a cohort study of 12,000 women

<p>Background: Rapid testing of pregnant women aims to increase uptake of HIV testing and results and thus optimize care. We report on the acceptability of HIV counselling and testing, and uptake of results, before and after the introduction of rapid testing in this area.</p> <p>Methods and Principal Findings: HIV counsellors offered counselling and testing to women attending 8 antenatal clinics, prior to enrolment into a study examining infant feeding and postnatal HIV transmission. From August 2001 to April 2003, blood was sent for HIV ELISA testing in line with the Prevention of Mother-to-Child Transmission (PMTCT) programme in the district. From May 2003 to September 2004 women were offered a rapid HIV test as part of the PMTCT programme, but also continued to have ELISA testing for study purposes. Of 12,323 women counselled, 5,879 attended clinic prior to May 2003, and 6,444 after May 2003 when rapid testing was introduced; of whom 4,324 (74.6%) and 4,810 (74.6%) agreed to have an HIV test respectively. Of the 4,810 women who had a rapid HIV test, only 166 (3.4%) requested to receive their results on the same day as testing, the remainder opted to return for results at a later appointment. Women with secondary school education were less likely to agree to testing than those with no education (AOR 0.648, p<0.001), as were women aged 21–35 (AOR 0.762, p<0.001) and >35 years (AOR 0.756, p<0.01) compared to those <20 years.</p> <p>Conclusions: Contrary to other reports, few women who had rapid tests accepted their HIV results the same day. Finding strategies to increase the proportion of pregnant women knowing their HIV results is critical so that appropriate care can be given.</p&gt

Sensitivity of WTP Estimates to Definition of \u27Yes\u27: Reinterpreting Expressed Response Intensity

Willingness to pay (WTP) estimation typically involves some strategy for mapping nondichotomous contingent valuation (CV) responses onto a dichotomous yes/no dependent variable. We propose a new approach to selecting which responses qualify as ‘yes.’ We apply the proposed method to polychotomous CV data for preventative land management programs in the Great Basin. We also estimate WTP using other methods of response recoding found in the literature. By contrasting the results under different approaches, we demonstrate how and why WTP point estimates vary across recoding methods and discuss the comparative advantages of our more generalized recoding approach that is based on predicted probabilities of ‘yes’ responses

Laser driven launch vehicles for continuous access to space

The availability of megawatt laser systems in the next century will make laser launch systems from ground to orbit feasible and useful. Systems studies indicate launch capabilities of 1 ton payload per gigawatt laser power. Recent research in ground to orbit laser propulsion has emphasized laser supported detonation wave thrusters driven by repetitively pulsed infrared lasers. In this propulsion concept each laser repetition cycle consists of two pulses. A lower energy first pulse is used to vaporize a small amount of solid propellant and then after a brief expansion period, a second and higher energy laser pulse is used to drive a detonation wave through the expanded vapor. The results are reported of numerical studies comparing the detonation wave properties of various candidate propellants, and the simulation of thruster performance under realistic conditions. Experimental measurements designed to test the theoretical predictions are also presented. Measurements are discussed of radiance and opacity in absorption waves, and mass loss and momentum transfer. These data are interpreted in terms of specific impulse and energy conversion efficiency

Soil Amplification at Treasure Island During the Loma Prieta Earthquake

The Loma Prieta Earthquake ground motions recorded on Treasure Island, a man-made fill in San Francisco Bay were considerably greater than on the adjacent Yerba Buena rock outcrop. The Yerba Buena motions were used as input to the computer program SHAKE90 for computing soil amplification at Treasure Island. Shear wave propagation velocities were obtained by seismic cone penetration testing. Reasonable agreement was observed between the computed and recorded accelerations at the strong motion recording station. The maximum computed accelerations around the island ranged from 0.13 to 0.20 g\u27s. The degree of damage at various locations on the island correlated somewhat with the maximum computed accelerations

Messages about dual contraception in areas of high HIV prevalence are not heeded

Background. Dual protection is recommended for prevention of unwanted pregnancies and protection against sexually transmitted infections, including HIV. It is critical for HIV-negative women to prevent seroconversion and HIV transmission to their infants during pregnancy and breastfeeding. Methods. Women were followed up after delivery, monthly for the first 9 months and then 3-monthly to 24 months, in a cohort study investigating postnatal HIV transmission. Study nurses discussed family planning, including condom use, at each visit. Contraceptive methods used since the last visit were recorded. All women knew their HIV status, and most women breastfed for a minimum of 6 months. Results. Among 1 137 HIV-positive and 1 220 HIV-negative women the most common contraceptive method was the hormonal injectable; few women used condoms alone or as dual contraception (0 - 3 months 6.8%; 7 - 12 months 16.3%; 19 - 24 months 14.4%). Compared with uninfected women, HIV-positive women were more likely to use condoms in years 1 and 2 after delivery (adjusted odds ratio (AOR) 1.72, 95% confidence interval (CI) 1.38 - 2.14,

The use of protocol in breaking bad news: evidence and ethos

This article discusses health professionals use of protocol in the breaking of bad news, focusing particularly on the well-known SPIKES framework. The evidence of impact on the patient experience is examined and recommendations are made for further outcome-based research. Existing evidence suggests that the model as commonly interpreted may not fully meet the needs of patients or reflect the clinical experience of breaking bad news for some professionals and further guidance may be needed to support them in their practice. The ethos of the step-wise protocol is debated, questioning whether it helps or hinders individualised care and the formation of a genuine relationship between patient and professional. Finally, recommendations for practice are offered