24 research outputs found
Knowledge and Attitudes on Contraception and Reproductive Health in Women With HIV
BACKGROUND: For reasons not fully explained to date, contraception usage among women with HIV remains low. The aim of our study was to understand attitudes toward and lifetime use of contraception among women with HIV.
METHODS: We administered an anonymous, community-informed, voluntary survey to cisgender, English-speaking women with HIV (≥18 years of age) at a Southern urban HIV clinic. It included multiple choice and Likert-scale questions on reproductive health. Participants reported contraception use, recollection of provider conversations about contraception, and perceived empowerment and knowledge regarding reproductive health. We used chi-square and Fisher exact tests to compare attitudes and prior conversations about contraception by age (\u3c vs ≥45 years), race (Black vs non-Black), and lifetime contraception use.
RESULTS: The median age of the 114 participants was 52 years, and 62% of the women identified as Black and 31% as White. Women reported a median of 2 unique family planning methods used throughout life, with oral contraceptive pills being most the common (59%). Only 20% of women reported having ever used long-acting reversible contraception (LARC). Only 56% of women recalled talking with a provider about contraception. Women of non-Black race and those who had used LARC were more likely to remember (72 vs 52%;
CONCLUSIONS: Throughout life, participants reported using a diversity of contraceptives. Only half of women remembered a provider conversation about contraception. Understanding women\u27s preferences regarding contraception should guide counseling
An assessment of rehabilitation success in an African grassland using ants as bioindicators
Many studies that evaluate rehabilitation make use of invertebrate bioindicators. Invertebrates,
especially ants, make useful indicators as they are sensitive to environmental change. We
compared ant assemblages in rehabilitated and control sites in the Rietvlei Nature Reserve, a
protected area important for grassland conservation in South Africa. Pitfall traps were used to
sample ant assemblages at six control sites and six rehabilitated sites. In addition, environmental
and vegetation surveys were conducted at each site. We found that the ant assemblages
differed significantly between the control and rehabilitated sites, although there was
considerable overlap; the control sites supported a greater species density and higher
abundance of ants than the rehabilitated sites. In total, 36 ant species were collected (control
sites: 34 species; rehabilitated sites: 26 species). The environmental survey revealed that
percentages of bare ground and coarse sand, as well as soil pH, differed significantly between
the control and rehabilitated sites. The control and rehabilitated sites also supported
significantly different plant assemblages. Three indicator ant species were identified for the
control sites: Crematogaster rectinota, Crematogaster amita and Monomorium fastidium. No
indicator species were identified for the rehabilitated sites. These results suggest that recovery
from the previous agricultural use of the area is still incomplete and highlights the lack of
research examining the success of rehabilitation in the grassland biome.
CONSERVATION IMPLICATIONS : The present study illustrates the need for further research on
rehabilitation techniques utilised in the grassland biome. This is of value as the remainder of
South African grasslands are considered critically endangered.The National Research
Foundationhttp://www.koedoe.co.zaam2016Plant ScienceZoology and Entomolog
An assessment of rehabilitation success in an African grassland using ants as bioindicators
Many studies that evaluate rehabilitation make use of invertebrate bioindicators. Invertebrates,
especially ants, make useful indicators as they are sensitive to environmental change. We
compared ant assemblages in rehabilitated and control sites in the Rietvlei Nature Reserve, a
protected area important for grassland conservation in South Africa. Pitfall traps were used to
sample ant assemblages at six control sites and six rehabilitated sites. In addition, environmental
and vegetation surveys were conducted at each site. We found that the ant assemblages
differed significantly between the control and rehabilitated sites, although there was
considerable overlap; the control sites supported a greater species density and higher
abundance of ants than the rehabilitated sites. In total, 36 ant species were collected (control
sites: 34 species; rehabilitated sites: 26 species). The environmental survey revealed that
percentages of bare ground and coarse sand, as well as soil pH, differed significantly between
the control and rehabilitated sites. The control and rehabilitated sites also supported
significantly different plant assemblages. Three indicator ant species were identified for the
control sites: Crematogaster rectinota, Crematogaster amita and Monomorium fastidium. No
indicator species were identified for the rehabilitated sites. These results suggest that recovery
from the previous agricultural use of the area is still incomplete and highlights the lack of
research examining the success of rehabilitation in the grassland biome.
CONSERVATION IMPLICATIONS : The present study illustrates the need for further research on
rehabilitation techniques utilised in the grassland biome. This is of value as the remainder of
South African grasslands are considered critically endangered.The National Research
Foundationhttp://www.koedoe.co.zaam2016Plant ScienceZoology and Entomolog
Changes in bird assemblages because of vegetation homogenisation in communal livestock systems
Protected areas are intended to promote biodiversity representation and persistence; yet, whether they are effective in degraded landscapes where much of the original vegetation structure remains intact has received relatively little attention. We test whether avian assemblages in communal rangelands in savannas differ from savannas supporting a full complement of native herbivores and predators. Birds were surveyed in 36 transect counts conducted over 18 days. We also compare the vegetation structure between the two land-use types to assess whether differences in bird assemblages could be attributed to changes in vegetation structure. Bird assemblages were richer, had greater abundances and different compositions inside protected areas than rangelands. The median body mass of birds was larger inside than outside protected areas, and rangelands supported fewer grassland specialists, but more closed-canopy specialists. However, no differences in feeding guild composition were found between protected areas and communal rangelands. Additionally, vegetation structure, but not richness, differed between protected areas and communal rangelands: communal rangelands had higher densities of woody vegetation and shorter grass height than the protected areas. Our findings suggest that the altered vegetation structure in communal grazing camps has led to changes in the species richness and composition of bird communities and has been selected by closed-canopy specialists at the cost of open grassy specialists. Hunting in communal rangelands is likely to have resulted in the loss of large birds and in reductions in bird abundance in the rangelands. Therefore, land-use management that does not lead to irreversible landscape transformation can nevertheless result in changes in the diversity, composition and functioning of native assemblages.
Conservation implications: Savanna landscapes that are degraded, but not transformed, support fewer bird species, fewer open habitat specialists and smaller birds because of vegetation homogenisation.South African National Research Foundationhttps://koedoe.co.zapm2020Plant Production and Soil Scienc
The role of deterministic succession during forest development within a southern African savanna
Woody encroachment can lead to a switch from open savannas to dense woodlands or forests. This has implications for both the composition of ecological communities and the provision of ecosystem services such as nutrient cycling and grazing capacity. The patterns and underlying drivers responsible for woody encroachment are not fully understood. Here, we investigate the underlying determinants of bush clump formation (a form of encroachment) in a South African savanna and explore whether bush clump succession is driven by deterministic (i.e., predictable changes in species composition) or stochastic (i.e., random) processes. Specifically, we test (1) whether the similarity in species composition of saplings and trees differs among small and large clumps, (2) which environmental factors are driving succession, and (3) whether forest specialization of tree and sapling species within bush clumps increases with the successional gradient. Similarity in species composition between saplings in small clumps and trees in large clumps was higher than similarity between trees in small clumps and trees in large clumps. Furthermore, temperature, soil moisture, relative humidity, and light intensity were related to changes in species composition along the successional gradient. As expected, forest specialization of trees increased with increasing clump area indicating that late‐successional bush clumps have more forest‐type species. The directional changes of species found along the successional gradient suggest a deterministic process of succession driven by changes in local environmental conditions during clump formation.The Universiteit van Amsterdam (UvA) and the National Research Foundation.http://wileyonlinelibrary.com/journal/btp2022-03-10hj2021Forestry and Agricultural Biotechnology Institute (FABI)Plant Production and Soil Scienc
Deterministic processes have limited impacts on foliar fungal endophyte communities along a savanna-forest successional gradient
Patterns and drivers of succession provide insight into the mechanisms that govern community assembly, but
remain poorly understood for microbial communities. We assess whether successional trends of trees are
mirrored by foliar endophyte communities of three tree species across a deterministic woody successional
gradient. Additionally, we test the relative contribution of abiotic predictors, biotic factors, and spatial distance
between sites in predicting composition and richness of endophyte communities. Unlike the tree community,
endophyte communities showed no consistent evidence of deterministic succession. Host identity was the most
important factor structuring endophyte community composition; within hosts, spatial distance from the indigenous
forest and between samples was important, while environmental predictors had small and inconsistent
effects. Much variation in endophyte composition remained unexplained. In contrast, endophyte richness was
well-explained by predictor variables. Host identity was most important in predicting endophyte richness, while
the effect of other predictors on richness differed between host species. We conclude that deterministic succession
in trees did not result in deterministic succession in endophyte communities; instead community assembly
was most strongly influenced by host identity; while within hosts, neutral processes may be more
important for endophyte assembly than deterministic factors.The Tree Protection Co-operative Program (TPCP), the centre of excellence in plant health and biotechnology (CPHB) and the South African National Research Foundation.http://www.elsevier.com/locate/funecoam2024BiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant PathologyPlant Production and Soil ScienceSDG-15:Life on lan
Origins Space Telescope: Baseline mission concept
The Origins Space Telescope will trace the history of our origins from the time dust and heavy elements permanently altered the cosmic landscape to present-day life. How did galaxies evolve from the earliest galactic systems to those found in the Universe today? How do habitable planets form? How common are life-bearing worlds? To answer these alluring questions, Origins will operate at mid-and far-infrared (IR) wavelengths and offer powerful spectroscopic instruments and sensitivity three orders of magnitude better than that of the Herschel Space Observatory, the largest telescope flown in space to date. We describe the baseline concept for Origins recommended to the 2020 US Decadal Survey in Astronomy and Astrophysics. The baseline design includes a 5.9-m diameter telescope cryocooled to 4.5 K and equipped with three scientific instruments. A mid-infrared instrument (Mid-Infrared Spectrometer and Camera Transit spectrometer) will measure the spectra of transiting exoplanets in the 2.8 to 20 μm wavelength range and offer unprecedented spectrophotometric precision, enabling definitive exoplanet biosignature detections. The far-IR imager polarimeter will be able to survey thousands of square degrees with broadband imaging at 50 and 250 μm. The Origins Survey Spectrometer will cover wavelengths from 25 to 588 μm, making wide-area and deep spectroscopic surveys with spectral resolving power R ∼ 300, and pointed observations at R ∼ 40,000 and 300,000 with selectable instrument modes. Origins was designed to minimize complexity. The architecture is similar to that of the Spitzer Space Telescope and requires very few deployments after launch, while the cryothermal system design leverages James Webb Space Telescope technology and experience. A combination of current-state-of-the-art cryocoolers and next-generation detector technology will enable Origins\u27 natural background-limited sensitivity
Origins Space Telescope: baseline mission concept
The Origins Space Telescope will trace the history of our origins from the time dust and heavy elements permanently altered the cosmic landscape to present-day life. How did galaxies evolve from the earliest galactic systems to those found in the Universe today? How do habitable planets form? How common are life-bearing worlds? To answer these alluring questions, Origins will operate at mid- and far-infrared (IR) wavelengths and offer powerful spectroscopic instruments and sensitivity three orders of magnitude better than that of the Herschel Space Observatory, the largest telescope flown in space to date. We describe the baseline concept for Origins recommended to the 2020 US Decadal Survey in Astronomy and Astrophysics. The baseline design includes a 5.9-m diameter telescope cryocooled to 4.5 K and equipped with three scientific instruments. A mid-infrared instrument (Mid-Infrared Spectrometer and Camera Transit spectrometer) will measure the spectra of transiting exoplanets in the 2.8 to 20 μm wavelength range and offer unprecedented spectrophotometric precision, enabling definitive exoplanet biosignature detections. The far-IR imager polarimeter will be able to survey thousands of square degrees with broadband imaging at 50 and 250 μm. The Origins Survey Spectrometer will cover wavelengths from 25 to 588 μm, making wide-area and deep spectroscopic surveys with spectral resolving power R ∼ 300, and pointed observations at R ∼ 40,000 and 300,000 with selectable instrument modes. Origins was designed to minimize complexity. The architecture is similar to that of the Spitzer Space Telescope and requires very few deployments after launch, while the cryothermal system design leverages James Webb Space Telescope technology and experience. A combination of current-state-of-the-art cryocoolers and next-generation detector technology will enable Origins’ natural background-limited sensitivity