Renal health after long-term exposure to tenofovir disoproxil fumarate (TDF) in HIV/HBV positive adults in Ghana

Objectives: The study assessed markers of renal health in HIV/HBV co-infected patients receiving TDF- containing antiretroviral therapy in Ghana. Methods: Urinary protein-to-creatinine ratio (uPCR) and albumin-to-protein ratio (uAPR) were measured cross-sectionally after a median of four years of TDF. At this time, alongside extensive laboratory testing, patients underwent evaluation of liver stiffness and blood pressure. The estimated glomerular filtration rate (eGFR) was measured longitudinally before and during TDF therapy. Results: Among 101 participants (66% women, median age 44 years, median CD4 count 572 cells/mm 3 ) 21% and 17% had detectable HIV-1 RNA and HBV DNA, respectively. Overall 35% showed hypertension, 6% diabetes, 7% liver stiffness indicative of cirrhosis, and 18% urinary excretion of Schistosoma antigen. Tubular proteinuria occurred in 16% of patients and was independently predicted by female gender and hypertension. The eGFR declined by median 1.8 ml/min/year during TDF exposure (IQR −4.4, −0.0); more pronounced declines ( ≥5 ml/min/year) occurred in 22% of patients and were associated with receiv-ing ritonavir-boosted lopinavir rather than efavirenz. HBV DNA, HBeAg, transaminases, and liver stiffness were not predictive of renal function abnormalities. Conclusions: The findings mandate improved diagnosis and management of hypertension and suggest targeted laboratory monitoring of patients receiving TDF alongside a booster in sub-Saharan Africa

Biologic Cycling of Silica across a Grassland Bioclimosequence

The dynamics of biologic Si cycling in grassland ecosystems are largely unknown and likely to impact mineral weathering rates regionally and diatom productivity globally; key regulatory processes in the global Si cycle are closely tied to the global carbon cycle. Across a bioclimatic sequence spanning major grassland ecosystems in the Great Plains, soil biogenic silica depth distributions are similar to that of soil organic carbon; however, unlike soil organic carbon, quantities of soil biogenic silica decrease with increasing precipitation, despite an increase in annual biogenic inputs through litterfall across the same gradient. Though comprising only 1–3% of the total Si pool, faster turnover of biogenic Si and annual cycling by grasses should positively impact mineral dissolution. Our results suggest that the largest reservoir of biogenic Si in terrestrial ecosystems resides in soils, and emphasize the potential significance of grasslands in the global biogeochemical cycle of Si

Presentation and outcome of COVID-19 in HIV patients with high viral loads and opportunistic infections: a case series

Coronavirus disease 2019 (COVID-19) is especially severe in patients with underlying chronic conditions, with increased risk of mortality. There is concern that people living with HIV (PLWH), especially those with severe immunosuppression, and COVID-19 may have severe disease and a negative clinical outcome. Most studies on COVID-19 in PLWH are from Asia, Europe and America where population dynamics, antiretroviral treatment coverage and coexisting opportunistic infections may differ from that in sub-Saharan Africa. We report on the clinical profile and outcome of three cases of PLWH co-infected with SARS-CoV-2. They all presented with fever, cough and breathlessness and also had advanced HIV infection as evidenced by opportunistic infections, high HIV viral loads and low CD4 counts. The patients responded favourably to the standard of care and were discharged home. Our findings suggest that PLWH with advanced immunosuppression may not necessarily have an unfavourable disease course and outcome. However, case-controlled studies with a larger population size are needed to better understand the impact of COVID-19 in this patient population

In vitro determination of Sun Protection Factor on Clays Used for Cosmetic Purposes in Kenya

Ultraviolet radiation is a real problem to human health and it’s said to cause skin cancer and related skin ailments. These diseases are of economic burden in terms of diagnosis, treatment and prevention in low and middle level countries. Commercial sunscreens are considered as the most effective way of preventing the incidences of skin cancer, however they are costly, unavailable and they contain toxic ingredients, which can in the end be cancerous. Sunscreens from natural sources like plants and clay are currently being explored as cheap, reliable, and available and may offer simple alternative health benefits. The purpose of this study was to evaluate the amount of sun protection factor (SPF) offered by cosmetic clays used in Kenya by different communities. The SPF was determined in vitro using 3 M transpore adhesive tapes on twelve clay samples collected randomly from sites used in three counties namely Narok, Bomet and Bungoma. Using a spreading protocol of 2 µg/cm2 transmittances between 280 to 400 nm were measured using a UV 1800 Shimadzu, Japan spectrophotometer. A commercial sunscreen with known SPF was incorporated in the study as a positive control. The SPF values of the clays were found to be between 1.46 and 40.98. The SPF value obtained for the commercial sunscreen differed from the SPF cited by the manufacturer. A second method was used on the commercial sunscreen and values obtained were in close agreement with those used in the first method. This study revealed that clays used for cosmetic purposes offer some form of sun protection to its users. Determination of SPF using Transpore tape is cheap, easy to handle, readily available and rapid. Keywords: Sun Protection factor, Clay

Topo-edaphic controls over woody plant biomass in South African savannas

The distribution of woody biomass in savannas reflects spatial patterns fundamental to ecosystem processes, such as water flow, competition, and herbivory, and is a key contributor to savanna ecosystem services, such as fuelwood supply. While total precipitation sets an upper bound on savanna woody biomass, the extent to which substrate and terrain constrain trees and shrubs below this maximum remains poorly understood, often occluded by local-scale disturbances such as fire and trampling. Here we investigate the role of hillslope topography and soil properties in controlling woody plant aboveground biomass (AGB) in Kruger National Park, South Africa. Large-area sampling with airborne Light Detection and Ranging (LiDAR) provided a means to average across local-scale disturbances, revealing an unexpectedly linear relationship between AGB and hillslope-position on basalts, where biomass levels were lowest on crests, and linearly increased toward streams (<i>R</i><sup>2</sup> = 0.91). The observed pattern was different on granite substrates, where AGB exhibited a strongly non-linear relationship with hillslope position: AGB was high on crests, decreased midslope, and then increased near stream channels (<i>R</i><sup>2</sup> = 0.87). Overall, we observed 5-to-8-fold lower AGB on clayey, basalt-derived soil than on granites, and we suggest this is due to herbivore-fire interactions rather than lower hydraulic conductivity or clay shrinkage/swelling, as previously hypothesized. By mapping AGB within and outside fire and herbivore exclosures, we found that basalt-derived soils support tenfold higher AGB in the absence of fire and herbivory, suggesting high clay content alone is not a proximal limitation on AGB. Understanding how fire and herbivory contribute to AGB heterogeneity is critical to predicting future savanna carbon storage under a changing climate

An assessment of minimum sequence copy thresholds for identifying and reducing the prevalence of artefacts in dietary metabarcoding data

1. Metabarcoding provides a powerful tool for investigating biodiversity and trophic interactions, but the high sensitivity of this methodology makes it vulnerable to errors, resulting in artefacts in the final data. Metabarcoding studies thus often utilise minimum sequence copy thresholds (MSCTs) to remove artefacts that remain in datasets; however, there is no consensus on best practice for the use of MSCTs. 2. To mitigate erroneous reporting of results and inconsistencies, this study discusses and provides guidance for best-practice filtering of metabarcoding data for the ascertainment of conservative and accurate data. Several of the most commonly used MSCTs were applied to example datasets of Eurasian otter Lutra lutra and cereal crop spider (Araneae: Linyphiidae and Lycosidae) diets. 3. Changes in both the method and threshold value considerably affected the resultant data. Of the MSCTs tested, it was concluded that the optimal method for the examples given combined a sample-based threshold with removal of maximum taxon contamination, providing stringent filtering of artefacts while retaining target data. 4. Choice of threshold value differed between datasets due to variation in artefact abundance and sequencing depth, thus studies should employ controls (mock communities, negative controls with no DNA and unused MID tag combinations) to select threshold values appropriate for each individual study

Strengthening impact assessment: a call for integration and focus

We suggest that the impact assessment community has lost its way based on our observation that impact assessment is under attack because of a perceived lack of efficiency. Specifically, we contend that the proliferation of different impact assessment types creates separate silos of expertise and feeds arguments for not only a lack of efficiency but also a lack of effectiveness of the process through excessive specialisation and a lack of interdisciplinary practice. We propose that the solution is a return to the basics of impact assessment with a call for increased integration around the goal of sustainable development and focus through better scoping. We rehearse and rebut counter arguments covering silo-based expertise, advocacy, democracy, sustainability understanding and communication. We call on the impact assessment community to rise to the challenge of increasing integration and focus, and to engage in the debate about the means of strengthening impact assessment

On the role of laser-induced microstructures in influencing the surface energy of magnesia partially stabilized zirconia bioceramic

Surface energy must in some way be connected to surface chemistry and is therefore an important determinant of a biomaterial’s functions. This work elucidates the basic phenomena and wetting mechanisms associated for a widely used bioinert ceramic, magnesia partially stabilized zirconia (MgO-PSZ) following CO2 laser treatment. Contact angles for a set of test liquids were used to measure the wettability characteristics and to reduce the surface energy of the MgO-PSZ before and after CO2 laser treatment. CO2 laser treatment of the MgO-PSZ surface was seen to effect an improvement in the material’s wettability characteristics. Furthermore, it was found that the extent of wettability modi®cation was closely related to the microstructure induced by CO2 laser radiation on the surface of the MgO-PSZ