No one may be refused emergency medical treatment in South Africa (SA). Yet score-based categorical exclusions used in critical care triage guidelines disproportionately discriminate against older ...adults, the cognitively and physically impaired, and the disabled. Adults over the age of 60, who make up 9.1% of the SA population, are most likely to present with disabilities and comorbidities at triage. Score-based models, drawn from international precedents, deny these patients admission to an ICU when resources are constrained, such as during influenza and COVID-19 outbreaks. The Critical Care Society of Southern Africa and the South African Medical Association adopted the Clinical Frailty Scale, which progressively withholds admission to ICUs based on age, frailty and comorbidities in a manner that potentially contravenes constitutional and equality prohibitions against unfair discrimination. The legal implications for healthcare providers are extensive, ranging from personal liability to hate speech and crimes against humanity. COVID-19 guidelines and score-based triage protocols must be revised urgently to eliminate unlawful discrimination against legally protected categories of patients in SA, including the disabled and the elderly. That will ensure legal certainty for health practitioners, and secure the full protections of the law to which the health-vulnerable and those of advanced age are constitutionally entitled.
Southern Africa is expected to experience increased frequency and intensity of droughts through climate change, which will adversely affect mammalian herbivores. Using bio-loggers, we tested the ...expectation that wildebeest (Connochaetes taurinus), a grazer with high water-dependence, would be more sensitive to drought conditions than the arid-adapted gemsbok (Oryx gazella gazella). The study, conducted in the Kalahari, encompassed two hot-dry seasons with similar ambient temperatures but differing rainfall patterns during the preceding wet season. In the drier year both ungulates selected similar cooler microclimates, but wildebeest travelled larger distances than gemsbok, presumably in search of water. Body temperatures in both species reached lower daily minimums and higher daily maximums in the drier season but daily fluctuations were wider in wildebeest than in gemsbok. Lower daily minimum body temperatures displayed by wildebeest suggest that wildebeest were under greater nutritional stress than gemsbok. Moving large distances when water is scarce may have compromised the energy balance of the water dependent wildebeest, a trade-off likely to be exacerbated with future climate change.
Context.
The Asteroid Terrestrial-impact Last Alert System (ATLAS) is an all-sky survey primarily aimed at detecting potentially hazardous near-Earth asteroids. Apart from the astrometry of ...asteroids, it also produces their photometric measurements that contain information about asteroid rotation and their shape.
Aims.
To increase the current number of asteroids with a known shape and spin state, we reconstructed asteroid models from ATLAS photometry that was available for approximately 180 000 asteroids observed between 2015 and 2018.
Methods.
We made use of the light-curve inversion method implemented in the Asteroids@home project to process ATLAS photometry for roughly 100 000 asteroids with more than a hundred individual brightness measurements. By scanning the period and pole parameter space, we selected those best-fit models that were, according to our setup, a unique solution for the inverse problem.
Results.
We derived ~2750 unique models, 950 of them were already reconstructed from other data and published. The remaining 1800 models are new. About half of them are only partial models, with an unconstrained pole ecliptic longitude. Together with the shape and spin, we also determined for each modeled asteroid its color index from the cyan and orange filter used by the ATLAS survey. We also show the correlations between the color index, albedo, and slope of the phase-angle function.
Conclusions.
The current analysis is the first inversion of ATLAS asteroid photometry, and it is the first step in exploiting the huge scientific potential that ATLAS photometry has. ATLAS continues to observe, and in the future, this data, together with other independent photometric measurements, can be inverted to produce more refined asteroid models.
Woody encroachment in ‘open’ biomes like grasslands and savannahs is occurring globally. Both local and global drivers, including elevated CO2, have been implicated in these increases. The relative ...importance of different processes is unresolved as there are few multi-site, multi-land-use evaluations of woody plant encroachment. We measured 70 years of woody cover changes over a 1020 km2 area covering four land uses (commercial ranching, conservation with elephants, conservation without elephants and communal rangelands) across a rainfall gradient in South African savannahs. Different directions of woody cover change would be expected for each different land use, unless a global factor is causing the increases. Woody cover change was measured between 1940 and 2010 using the aerial photo record. Detection of woody cover from each aerial photograph was automated using eCognitions' Object-based image analysis (OBIA). Woody cover doubled in all land uses across the rainfall gradient, except in conservation areas with elephants in low-rainfall savannahs. Woody cover in 2010 in low-rainfall savannahs frequently exceeded the maximum woody cover threshold predicted for African savannahs. The results indicate that a global factor, of which elevated CO2 is the likely candidate, may be driving encroachment. Elephants in low-rainfall savannahs prevent encroachment and localized megafaunal extinction is a probable additional cause of encroachment.
This article is part of the themed issue ‘Tropical grassy biomes: linking ecology, human use and conservation’.
Background Influenza co-infection with bacteria is a leading cause of influenza-related deaths and severe respiratory infections, especially among high-risk groups like cancer patients undergoing ...treatment. However, acute respiratory infection (ARI)-like symptoms developed by upper-torso cancer (UTC) patients receiving radiotherapy are considered as side-effects of the radiation. Hence influenza and bacterial pathogens implicated in ARI are not investigated. Methods This prospective cohort study examined 85 in-patients with upper-torso cancers undergoing radiotherapy at the National Radiotherapy, Oncology and Nuclear Medicine Centre (NRONMC) of Korle-Bu Teaching Hospital (KBTH) in Accra, Ghana. Eligible patients who consented were recruited into the study from September 2018 to April 2019. Influenza viruses A and B in addition to the following bacteria species Streptococcus pneumonia, Haemophilus influenzae, Neisseria meningitidis and Staphylococcus aureus were detected from oropharyngeal and nasopharyngeal swab specimens collected at three different time points. Presence of respiratory pathogens were investigated by influenza virus isolation in cell culture, bacterial culture, polymerase chain reaction (PCR) and next generation sequencing (NGS) assays. Results Of the 85 eligible participants enrolled into the study, 87% were females. Participants were 17 to 77 years old, with a median age of 49 years. Most of the participants (88%) enrolled had at least one pathogen present. The most prevalent pathogen was N. meningitidis (63.4%), followed by H. influenzae (48.8%), Influenza viruses A and B (32.9%), S. pneumoniae (32.9%) and S. aureus (12.2%). Approximately, 65% of these participants developed ARI-like symptoms. Participants with previous episodes of ARI, did not live alone, HNC and total radiation less than 50 Gy were significantly associated with ARI. All treatment forms were also significantly associated with ARI. Conclusion Data generated from the study suggests that ARI-like symptoms observed among UTC patients receiving radiotherapy in Ghana, could be due to influenza and bacterial single and co-infections in addition to risk factors and not solely the side-effects of radiation as perceived. These findings will be prime importance for diagnosis, prevention, treatment and control for cancer patients who present with such episodes during treatment.
We present here multiband photometry for over 2000 Main-Belt asteroids. For each target, we report the probabilistic taxonomy using the measured V - R and V - I colors in combination with a ...machine-learning-generated decision surface in color-color space. Through this method, we classify >85% of our targets as one the four main Bus-DeMeo complexes: S-, C-, X-, or D-type. Roughly one-third of our targets have a known associated dynamic family, with 69 families represented in our data. Within uncertainties, our results show no discernible difference in taxonomic distribution between family members and non-family members. Nine of the sixty-nine families represented in our observed sample had 20 or more members present, and therefore, we investigate the taxonomy of these families in more detail and find excellent agreement with the literature. Out of these nine well-sampled families, our data show that the Themis, Koronis, Hygiea, Massalia, and Eunomia families display a high degree of taxonomic homogeneity and that the Vesta, Flora, Nysa-Polana, and Eos families show a significant level of mixture in taxonomies. Using the taxonomic purity and the degree of dispersion in observed colors for each of the nine well-sampled collisional families, we also speculate which of these families potentially originated from a differentiated parent body and/or is a family with a possible undetermined nested family. In addition, we obtained sufficient photometric data for 433 of our targets to extract reliable rotation periods and observe no obvious correlation between rotation properties and family membership.
Woody biomass dynamics are an expression of ecosystem function, yet biomass estimates do not provide information on the spatial distribution of woody vegetation within the vertical vegetation ...subcanopy. We demonstrate the ability of airborne light detection and ranging (LiDAR) to measure aboveground biomass and subcanopy structure, as an explanatory tool to unravel vegetation dynamics in structurally heterogeneous landscapes. We sampled three communal rangelands in Bushbuckridge, South Africa, utilised by rural communities for fuelwood harvesting. Woody biomass estimates ranged between 9 Mg ha(-1) on gabbro geology sites to 27 Mg ha(-1) on granitic geology sites. Despite predictions of woodland depletion due to unsustainable fuelwood extraction in previous studies, biomass in all the communal rangelands increased between 2008 and 2012. Annual biomass productivity estimates (10-14% p.a.) were higher than previous estimates of 4% and likely a significant contributor to the previous underestimations of modelled biomass supply. We show that biomass increases are attributable to growth of vegetation <5 m in height, and that, in the high wood extraction rangeland, 79% of the changes in the vertical vegetation subcanopy are gains in the 1-3 m height class. The higher the wood extraction pressure on the rangelands, the greater the biomass increases in the low height classes within the subcanopy, likely a strong resprouting response to intensive harvesting. Yet, fuelwood shortages are still occurring, as evidenced by the losses in the tall tree height class in the high extraction rangeland. Loss of large trees and gain in subcanopy shrubs could result in a structurally simple landscape with reduced functional capacity. This research demonstrates that intensive harvesting can, paradoxically, increase biomass and this has implications for the sustainability of ecosystem service provision. The structural implications of biomass increases in communal rangelands could be misinterpreted as woodland recovery in the absence of three-dimensional, subcanopy information.
ABSTRACT
We present here the discovery of a new class of superslow rotating asteroids (Prot ≳1000 h) in data extracted from the Asteroid Terrestrial-impact Last Alert System (ATLAS) and Zwicky ...Transient Facility (ZTF) all-sky surveys. Of the 39 rotation periods we report here, 32 have periods longer than any previously reported unambiguous rotation periods currently in the Asteroid Light Curve Data base. In our sample, seven objects have a rotation period >4000 h and the longest period we report here is 4812 h (∼200 d). We do not observe any correlation between taxonomy, albedo, or orbital properties with superslow rotating status. The most plausible mechanism for the creation of these very slow rotators is if their rotations were slowed by YORP spin-down. Superslow rotating asteroids may be common, with at least 0.4 per cent of the main-belt asteroid population with a size range between 2 and 20 km in diameter rotating with periods longer than 1000 h.
Quality conservation planning requires quality input data. However, the broad scale sampling strategies typically employed to obtain primary species distribution data are prone to geographic bias in ...the form of errors of omission. This study provides a quantitative measure of sampling bias to inform accuracy assessment of conservation plans based on the South African Frog Atlas Project. Significantly higher sampling intensity near to cities and roads is likely to result in overstated conservation priority and heightened conservation conflicts in urban areas. Particularly well sampled protected areas will also erroneously appear to contribute highly to amphibian biodiversity targets. Conversely, targeted sampling in the arid northwest and along mountain ranges is needed to ensure that these under-sampled regions are not excluded from conservation plans. The South African Frog Atlas Project offers a reasonably accurate picture of the broad scale west-to-east increase in amphibian richness and abundance, but geographic bias may limit its applicability for fine scale conservation planning. The Global Amphibian Assessment species distribution data offered a less biased alternative, but only at the cost of inflated commission error.
Abstract
The growth of trees in riparian forests in semi-arid savannas is resilient to the natural variations in temperature and precipitation due to the availability of riverine water. Climate ...change can nevertheless, intensify the evapotranspiration of tree species, altering biodiversity, plant productivity and ecosystem services. Understanding the growth response of riparian tree species to climate change is, therefore, critical for their management and conservation. Here, we used 23 cross-dated stem discs of Anogeissus leiocarpus (DC.) Guill. and Perr. and Afzelia africana Sm. randomly sampled from riparian forests in the humid and dry savanna regions of Ghana to assess their growth response to climate change. A generalized additive mixed model (GAMM) was used to integrate species-specific basal area increments to an array of explanatory variables that may affect growth, including tree size and seasonal temperature and precipitation between 1982 and 2013. We observed significant association between tree size, rainy and dry season temperatures and precipitation variables, and changes in tree growth. Despite the strong fluctuations in tree growth over time, the estimated growth rates of the species from the residuals of the GAMMs showed no significant change in growth. Our findings suggest that these riparian forests are highly resistant to weather extremes and therefore, might persist (up to a certain point) even if climate change continues to intensify.
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