Randomised trials in the South African Medical Journal, 1948- 1997

Objective. To describe randomised controlled trials (RCTs) published in the South African Medical Journal (SAMJ) over a 50-year period from 1948 to 1997 with regard to number, topic and quality.Methods. We hand searched all issues of the SAMJ published during the study period to identify all published RCTs.Outcome measures. Number, topic and quality of RCTs published from 1948 to 1997.Results. Eight hundred and fifty-eight clinical trials were published during the period reviewed. Eighty-four per cent of RCTs were published as full articles. During the 1980s the number of RCTs published increased rapidly,  with a peak of 35 in 1985, but then declined to only 5 in 1997. The majority (92%) of RCTs were conducted in a hospital setting. A varied range of subjects was covered, with gastroenterology taking the lead and no trials in public health. The sample size in more than 50% of RCTs was smaller than 50 patients. Fifty-one per cent (435 trials) used random allocation and 49% (423) quasi-random methods of allocation. Concealment of treatment allocation was judged to be adequate in 46% of studies (N == 200), blinding of observers assessing outcomes was adequate in 28% (123), and all the allocated test subjects were included in the primary analysis in 28% (123). The follow-up period was more than 1 year in 4% (17) and less than 6 days in 16% (71).Conclusions. Compared with other international journals the SAMJ is highly regarded in terms of the number of trials published. There are, however, a number of deficiencies in the quality of the trials

Task shifting from doctors to non-doctors for initiation and maintenance of antiretroviral therapy

CITATION: Kredo, T. et al. 2014. Task shifting from doctors to non-doctors for initiation and maintenance of antiretroviral therapy. Cochrane Database of Systematic Reviews, 7:CD007331, doi:10.1002/14651858.CD007331.pub3.The original publication is available at https://www.cochranelibrary.comBackground: The high levels of healthcare worker shortage is recognised as a severe impediment to increasing patients’ access to antiretroviral therapy. This is particularly of concern where the burden of disease is greatest and the access to trained doctors is limited.This review aims to better inform HIV care programmes that are currently underway, and those planned, by assessing if task-shifting care from doctors to non-doctors provides both high quality and safe care for all patients requiring antiretroviral treatment. Objectives: To evaluate the quality of initiation and maintenance of HIV/AIDS care in models that task shift care from doctors to non-doctors.Publisher's versio

Basic characteristics of atmospheric particles, trace gases and meteorology in a relatively clean Southern African Savannah environment

We have analyzed one year (July 2006–July 2007) of measurement data from a relatively clean background site located in dry savannah in South Africa. The annual-median trace gas concentrations were equal to 0.7 ppb for SO<sub>2</sub>, 1.4 ppb for NO<sub>x</sub>, 36 ppb for O<sub>3</sub> and 105 ppb for CO. The corresponding PM<sub>1</sub>, PM<sub>2.5</sub> and PM<sub>10</sub> concentrations were 9.0, 10.5 and 18.8 μg m<sup>−3</sup>, and the annual median total particle number concentration in the size range 10–840 nm was 2340 cm<sup>−3</sup>. During Easterly winds, influence of industrial sources approximately 150 km away from the measurement site was clearly visible, especially in SO<sub>2</sub> and NO<sub>x</sub> concentrations. Of gases, NO<sub>x</sub> and CO had a clear annual, and SO<sub>2</sub>, NO<sub>x</sub> and O<sub>3</sub> clear diurnal cycle. Atmospheric new-particle formation was observed to take place in more than 90% of the analyzed days. The days with no new particle formation were cloudy or rainy days. The formation rate of 10 nm particles varied in the range of 0.1–28 cm<sup>−3</sup> s<sup>−1</sup> (median 1.9 cm<sup>−3</sup> s<sup>−1</sup>) and nucleation mode particle growth rates were in the range 3–21 nm h<sup>−1</sup> (median 8.5 nm h<sup>−1</sup>). Due to high formation and growth rates, observed new particle formation gives a significant contribute to the number of cloud condensation nuclei budget, having a potential to affect the regional climate forcing patterns

A cost assessment of intensive wild quail management on private lands in the southeastern United States

DATA AVAILABILITY STATEMENT : Deidentified data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to their containing information that could compromise the privacy of research participants.Private landowners who operate multifunctional landscapes play a critical role in the conservation of native and imperiled species, and the restoration of native ecosystems. In the southeastern United States, both northern bobwhite (Colinus virginianus) and pine savanna ecosystems are imperiled and heavily reliant on conservation efforts by private landowners. Engaging private landowners in the restoration and management of pine savannas and grasslands is essential to the recovery of northern bobwhite, which is also managed as a game species. Since the early 1900s, the cultural tradition of wild bobwhite hunting has motivated landowners to manage their properties to increase bobwhite populations. However, the costs and revenues associated with intensive wild bobwhite management and hunting are imperfectly understood. From May 2021 to February 2022, we conducted semistructured interviews with landowners and land managers of 37 wild bobwhite hunting properties (total of 65,317 ha in bobwhite management) in Alabama, Georgia, Florida, and South Carolina to enumerate the costs and revenues associated with intensive wild bobwhite management. Landowners spent an average of $154/acre/year (~$381/ha/year; median of $142/acre/year or ~$352/ha/year) to manage for northern bobwhite. These costs included salaries and benefits for labor, depreciated equipment and infrastructure expenditures, and other supplies (e.g., fuel, seed) needed to maintain wild bobwhite populations and their habitat. Few properties offset their bobwhite management costs with revenues generated on the property, including hunting revenues. Non-financial motivations for owning a bobwhite property included a strong land stewardship ethic, the desire to maintain rural lifestyles and family heritage, and securing hunting and recreational opportunities. Through wild quail management, private landowners are helping to secure critical habitat for threatened and endangered species and increasing the landscape's overall resilience to climate change without the use of public funding.Tall Timbers Research Station and Land Conservancy; Warnell School of Forestry and Natural Resources, University of Georgia.http://wileyonlinelibrary.com/journal/csp2hj2023Mammal Research Institut

The Parkes Observatory Pulsar Data Archive

The Parkes pulsar data archive currently provides access to 144044 data files obtained from observations carried out at the Parkes observatory since the year 1991. Around 10^5 files are from surveys of the sky, the remainder are observations of 775 individual pulsars and their corresponding calibration signals. Survey observations are included from the Parkes 70cm and the Swinburne Intermediate Latitude surveys. Individual pulsar observations are included from young pulsar timing projects, the Parkes Pulsar Timing Array and from the PULSE@Parkes outreach program. The data files and access methods are compatible with Virtual Observatory protocols. This paper describes the data currently stored in the archive and presents ways in which these data can be searched and downloaded.Comment: Accepted by PAS

Search for Two-Neutrino Double Electron Capture of 124^{124}Xe with XENON100

Two-neutrino double electron capture is a rare nuclear decay where two electrons are simultaneously captured from the atomic shell. For $^{124}$Xe this process has not yet been observed and its detection would provide a new reference for nuclear matrix element calculations. We have conducted a search for two-neutrino double electron capture from the K-shell of $^{124}$Xe using 7636 kg$\cdot$d of data from the XENON100 dark matter detector. Using a Bayesian analysis we observed no significant excess above background, leading to a lower 90 % credibility limit on the half-life $T_{1/2}>6.5\times10^{20}$ yr. We also evaluated the sensitivity of the XENON1T experiment, which is currently being commissioned, and find a sensitivity of $T_{1/2}>6.1\times10^{22}$ yr after an exposure of 2 t$\cdot$yr.Comment: 6 pages, 4 figure

Lowering the radioactivity of the photomultiplier tubes for the XENON1T dark matter experiment

The low-background, VUV-sensitive 3-inch diameter photomultiplier tube R11410 has been developed by Hamamatsu for dark matter direct detection experiments using liquid xenon as the target material. We present the results from the joint effort between the XENON collaboration and the Hamamatsu company to produce a highly radio-pure photosensor (version R11410-21) for the XENON1T dark matter experiment. After introducing the photosensor and its components, we show the methods and results of the radioactive contamination measurements of the individual materials employed in the photomultiplier production. We then discuss the adopted strategies to reduce the radioactivity of the various PMT versions. Finally, we detail the results from screening 216 tubes with ultra-low background germanium detectors, as well as their implications for the expected electronic and nuclear recoil background of the XENON1T experiment.Comment: 10 pages, 5 figure

Removing krypton from xenon by cryogenic distillation to the ppq level

The XENON1T experiment aims for the direct detection of dark matter in a cryostat filled with 3.3 tons of liquid xenon. In order to achieve the desired sensitivity, the background induced by radioactive decays inside the detector has to be sufficiently low. One major contributor is the $\beta$-emitter $^{85}$Kr which is an intrinsic contamination of the xenon. For the XENON1T experiment a concentration of natural krypton in xenon $\rm{^{nat}}$Kr/Xe < 200 ppq (parts per quadrillion, 1 ppq = 10$^{-15}$ mol/mol) is required. In this work, the design of a novel cryogenic distillation column using the common McCabe-Thiele approach is described. The system demonstrated a krypton reduction factor of 6.4$\cdot$10$^5$ with thermodynamic stability at process speeds above 3 kg/h. The resulting concentration of $\rm{^{nat}}$Kr/Xe < 26 ppq is the lowest ever achieved, almost one order of magnitude below the requirements for XENON1T and even sufficient for future dark matter experiments using liquid xenon, such as XENONnT and DARWIN