Spatial patterns of land-use by immature African white-backed vultures (Gyps africanus) captured in the North-West Province, South Africa

As obligate scavengers Gyps vultures provide an important ecosystem service as the main consumers of ungulate carcasses in African savannas. Throughout the continent, however, multiple threats are causing vulture populations to decline, especially outside protected areas. Although the African white-backed vulture Gyps africanus is the most numerous and widely distributed Gyps species in Africa, its foraging ecology and land use preferences remain poorly understood. Furthermore, while protected areas are known to be important for vultures in East and West Africa, their role in South Africa has not been fully investigated. This study uses GPS-GSM tracking units to investigate the movement and land-use patterns of six immature African white-backed vultures that were caught at Mankwe Wildlife Reserve in the North West Province of South Africa. Immature individuals were chosen because they were expected to travel extensively and be exposed to the full range of threats. The tracking units recorded the GPS location, speed, altitude and direction of travel three times per day. The size and extent of the vultures‟ foraging ranges were estimated using three methods: minimum convex polygons (MCPs), fixed kernel density estimation (KDE) and grid cell range (GCR) estimation. The vultures‟ use of protected areas and areas of different cattle densities (zero, low, medium and high) was assessed to determine whether they were visited more or less than expected based on the area they occupied within the vultures‟ foraging ranges. The distances travelled by the vultures and their flight speeds and altitudes were also calculated, as well as the amount of time that they spent in the vicinity of supplementary feeding sites. The vultures were tracked for between 101 and 313 days and the GPS tracking units acquired 99.44% of expected GPS locations. The vultures ranged extensively and generally travelled in a nomadic manner. While three individuals occupied foraging ranges (mean 95% KDE contour area = 106,282.33 km2) either side of the South African borders between Botswana and Zimbabwe, the other three travelled more extensively through southern Africa, entering six different countries (mean 95% KDE contour area = 563,564.67 km2). The vultures rarely visited protected areas in South Africa but two of the vultures regularly used protected areas in northern Botswana and Zimbabwe. Areas of high cattle density were used less than expected by all vultures, but not at a significant level, while two of the vultures used areas with zero cattle density more than expected due to their regular use of supplementary feeding sites in those areas. Areas of medium cattle density were the most regularly used, containing an average of 30.72% of each vulture‟s stationary GPS locations. The vultures travelled an average of 33 km/day and a maximum of 267 km/day, flying at an average of 50 km/h (maximum = 107 km/h) at 561 m above ground level (maximum = 2,267 m). This study provides the first description of movement and land-use patterns of immature African white-backed vultures tracked continuously from South Africa. Their extensive foraging ranges and limited use of protected areas implies that the vultures could potentially encounter the full range of threats in the region, and it is clear that their future conservation will depend upon conservation strategies that extend across international borders. CopyrightDissertation (MSc)--University of Pretoria, 2011.Paraclinical Sciencesunrestricte

UQ Open Science Conference 2018

This is a collection of resources and presentations for the Open Science Conference held at the University of Queensland, 24-25 September 201

Empagliflozin in Patients with Chronic Kidney Disease

Background The effects of empagliflozin in patients with chronic kidney disease who are at risk for disease progression are not well understood. The EMPA-KIDNEY trial was designed to assess the effects of treatment with empagliflozin in a broad range of such patients. Methods We enrolled patients with chronic kidney disease who had an estimated glomerular filtration rate (eGFR) of at least 20 but less than 45 ml per minute per 1.73 m(2) of body-surface area, or who had an eGFR of at least 45 but less than 90 ml per minute per 1.73 m(2) with a urinary albumin-to-creatinine ratio (with albumin measured in milligrams and creatinine measured in grams) of at least 200. Patients were randomly assigned to receive empagliflozin (10 mg once daily) or matching placebo. The primary outcome was a composite of progression of kidney disease (defined as end-stage kidney disease, a sustained decrease in eGFR to < 10 ml per minute per 1.73 m(2), a sustained decrease in eGFR of & GE;40% from baseline, or death from renal causes) or death from cardiovascular causes. Results A total of 6609 patients underwent randomization. During a median of 2.0 years of follow-up, progression of kidney disease or death from cardiovascular causes occurred in 432 of 3304 patients (13.1%) in the empagliflozin group and in 558 of 3305 patients (16.9%) in the placebo group (hazard ratio, 0.72; 95% confidence interval [CI], 0.64 to 0.82; P < 0.001). Results were consistent among patients with or without diabetes and across subgroups defined according to eGFR ranges. The rate of hospitalization from any cause was lower in the empagliflozin group than in the placebo group (hazard ratio, 0.86; 95% CI, 0.78 to 0.95; P=0.003), but there were no significant between-group differences with respect to the composite outcome of hospitalization for heart failure or death from cardiovascular causes (which occurred in 4.0% in the empagliflozin group and 4.6% in the placebo group) or death from any cause (in 4.5% and 5.1%, respectively). The rates of serious adverse events were similar in the two groups. Conclusions Among a wide range of patients with chronic kidney disease who were at risk for disease progression, empagliflozin therapy led to a lower risk of progression of kidney disease or death from cardiovascular causes than placebo