Current Paucity (current + paucity)

Distribution by Scientific Domains

Selected Abstracts

Ethical suicide research: A survey of researchers

Richard Lakeman
ABSTRACT Research is needed to better understand and respond effectively to people who are suicidal. Involving people who are suicidal in research poses some ethical and pragmatic problems. The ethical problems and difficulties in obtaining approval to involve people who are suicidal in research has contributed to the current paucity of research that explores the suicidal experience. To explore some of these problems, a web-based survey of suicide researchers was undertaken. Researchers identified from published reports were contacted by email and invited to participate in a web-based survey. Researchers were asked to describe any problems they encountered, how ethical problems were negotiated or resolved, and any advice received from human research ethics committees. The main problems identified were accessing the population, maintaining confidentiality, the extent of care owed by the researcher to participants, and the facilitation of support to participants. As with clinical practice, ethical research involving people who are suicidal involves a process of sensitive engagement, and careful consideration and remediation of risk. [source]

Acacia species turnover in space and time in an African savanna

William J. Bond
Aim Patterns of species turnover along environmental gradients are better studied than their causes. Competitive interactions, or physiological tolerance are most often cited as determinants of turnover. Here we investigate differential tree species response to disturbance by fire and mammal browsing as causes of changing dominance of species within and among sites along an altitudinal gradient. Methods We documented the distribution of two Acacia species using maps and sample transects. We explored possible causes of species turnover by studying differences between the species in tolerance to grass competition using pot experiments, to browsers by observing patterns of shoot damage, and to fire by comparing the size structure of populations burnt at different frequencies and intensities. Results Acacia karroo woodlands were rare and occur at higher elevations than the much more common A. nilotica woodlands. Woodland composition seems set to change in future since the pattern of dominance was reversed in juvenile stages. A. karroo juveniles were very widespread and far more abundant than A. nilotica juveniles. A. karroo juveniles were most abundant in tall fire-prone grasslands and were rare on grazing lawns whereas A. nilotica showed the reverse pattern. In the pot experiments, growth of both species was suppressed by grasses but there were no significant differences in response between the two species. Juveniles of A. karroo were more heavily browsed than those of A. nilotica. However juveniles of A. nilotica were less tolerant of frequent intense burns than juvenile A. karroo. Main conclusions Disturbance gradients, from high fire frequency and low herbivore density at high altitudes, to lower fire frequency and higher herbivore density at low altitudes, are responsible for the shift in community structure along the spatial gradient. Differential responses to browsing and fire may also explain temporal turnover from A. nilotica in the past to A. karroo in the present. Changes in the area burnt annually, and in faunal composition, suggest a landscape-scale shift from grazing-dominated short-grass landscapes in the 1960s, favouring A. nilotica, to fire-dominated tall grasslands in the 1990s favouring A. karroo. We suggest that species turnover due to differential responses along disturbance gradients may be much more widespread than the current paucity of studies suggests. [source]

Is There Intergenerational Transmission of Trauma?

The Case of Combat Veterans' Children
This article is a review of the literature on intergenerational transmission of posttraumatic stress disorder (PTSD) from fathers to sons in families of war veterans. The review addresses several questions: (1) Which fathers have a greater tendency to transmit their distress to their offspring? (2) What is transmitted from father to child? (3) How is the distress transmitted and through which mechanisms? And finally, (4) Which children are more vulnerable to the transmission of PTSD distress in the family? Whereas the existing literature deals mainly with fathers' PTSD as a risk for increased emotional and behavior problems among the children, this review also highlights the current paucity of knowledge regarding family members and extrafamilial systems that may contribute to intergenerational transmission of PTSD or to its moderation. Little is also known about resilience and strengths that may mitigate or prevent the risk of intergenerational transmission of trauma. [source]

Overview: End-Stage Renal Disease in the Developing World

Rashad S. Barsoum
Abstract: Although the vast majority of patients with end-stage renal disease (ESRD) worldwide live in what is called the developing world, little is known about its epidemiology and management. With the current paucity of credible and adequately representative registries, it is justified to resort to innovative means of obtaining information. In this attempt, world-renowned leading nephrologists in 10 developing countries collaborated in filling a 103-item questionnaire addressing epidemiology, etiology, and management of ESRD in their respective countries on the basis of integrating available data from different sources. Through this joint effort, it was possible to identify a number of important trends. These include the expected high prevalence of ESRD, despite the limited access to renal replacement therapy, and the dependence of prevalence on wealth. Glomerulonephritis, rather than diabetes, remains as the main cause of ESRD with significant geographical variations in the prevailing histopathological types. The implementation of different modalities of renal replacement therapy (RRT) is inhibited by the lack of funding, although governments, insurance companies, and donations usually constitute the major sponsors. Hemodialysis is the preferred modality in most countries with the exception of Mexico where chronic ambulatory peritoneal dialysis (CAPD) takes the lead. In several other countries, dialysis is available only for those on the transplant waiting list. Dialysis is associated with a high frequency of complications particularly HBV and HCV infections. Data on HIV are lacking. Aluminum intoxication remains as a major problem in a number of countries. Treatment withdrawal is common for socioeconomic reasons. Transplantation is offered to an average of 4 per million population (pmp). Recipient exclusion criteria are minimal. Donor selection criteria are generally loose regarding tissue typing, remote viral infection, and, in some countries, blood-relation to the recipient in live-donor transplants. Cadaver donors are accepted in many countries participating in this survey. Treatment outcomes with different RRT modalities are, on the average, inferior to the internationally acknowledged standards largely due to infective and cardiovascular complications. [source]