Seasonal Dynamics and Defoliation Impact on Herbage Yield in Aspen Boreal Habitats of Alberta

Within the aspen boreal ecosystems, little information exists on the seasonal dynamics of available herbage and the effects of varying defoliation regimes on accumulated herbage growth and associated opportunities for animal production. We examined seasonal changes in herbage phytomass in conjunction with defoliation treatments in Bromus inermis-Poa pratensis grasslands in central Alberta. Changes in herbage pools were examined by sampling at five monthly intervals from April to September 1997 and 1998, inclusive. Vegetation was also subjected to a factorial experiment with an initial defoliation in late-May, June or July, at heights of 2.5, 7.5, or 15 cm, and repeated at 3-, 6- or 9-week intervals until the end of September. Green herbage, standing dead and fallen litter increased from spring to summer and decreased from summer to fall. Average growing conditions resulted in a peak phytomass of 350 g m-2, and varied by year. Weathering losses of green herbage, standing dead and fallen litter over winter were 34%, 52% and 51%, respectively. Dry matter losses of total herbage (all three pools) over winter were 58% of 1997 summer green phytomass. Initial timing, height, and frequency of clipping all affected accumulated herbage yield (P < 0.001). The greatest accumulated herbage yield was from clipping initiated in May. Light clipping resulted in less phytomass accumulation relative to moderate and heavy clipping. Clipping frequencies of six and nine weeks resulted in similar phytomass removal, but were greater than herbage removal associated with three weeks frequency. The interaction between clipping date and frequency of clipping demonstrates the importance of temporal rest and sensitivity of forage plants to defoliation, and lends support to the use of rotational grazing systems

Long-Term Effect of Group Support Psychotherapy on Depression and HIV Treatment Outcomes: Secondary Analysis of a Cluster Randomized Trial in Uganda

OBJECTIVE: We aimed to determine the effect of group support psychotherapy (GSP) compared with group HIV education (GHE) on depression and HIV treatment outcomes 24 months after treatment. We further aimed to investigate the mediating role of depression and antiretroviral therapy (ART) adherence in the relationship between GSP and viral load suppression. METHODS: Thirty HIV clinics across three districts were randomly assigned to deliver either GSP or GHE for depression. Depression and optimal (≥95%) ART adherence was assessed at baseline and 6, 12, 18, and 24 months after treatment. Viral load was drawn from the medical charts at baseline and 12 and 24 months after treatment. Multilevel mixed-effects regression models and generalized structural equation modeling were used to estimate 24-month outcomes and mediation effects. RESULTS: Participants ( N = 1140) were enrolled from HIV clinics offering either GSP ( n = 578 [51%]) or GHE ( n = 562 [49%]). Fewer GSP than GHE participants met the criteria for depression at 24 months after treatment (1% versus 25%; adjusted odds ratio [aOR] = 0.002, 95% confidence interval [CI] = 0.0002-0.018). More GSP than GHE participants reported optimal (≥95%) ART adherence (96% versus 88%; aOR = 20.88, 95% CI = 5.78-75.33) and improved viral suppression (96% versus 88%; aOR = 3.38, 95% CI = 1.02-11.02). The indirect effects of GSP through sequential reduction in depression and improvement in ART adherence at 12 months may partially explain the higher viral suppression rates at 24 months in GSP than GHE groups. CONCLUSION: In settings where the HIV epidemic persists, depression treatment with GSP may be critical for optimal HIV treatment outcomes.Trial Registration: The Pan African Clinical Trials Registry, number PACTR201608001738234

High aboveground carbon stock of African tropical montane forests

Tropical forests store 40-50 per cent of terrestrial vegetation carbon(1). However, spatial variations in aboveground live tree biomass carbon (AGC) stocks remain poorly understood, in particular in tropical montane forests(2). Owing to climatic and soil changes with increasing elevation(3), AGC stocks are lower in tropical montane forests compared with lowland forests(2). Here we assemble and analyse a dataset of structurally intact old-growth forests (AfriMont) spanning 44 montane sites in 12 African countries. We find that montane sites in the AfriMont plot network have a mean AGC stock of 149.4 megagrams of carbon per hectare (95% confidence interval 137.1-164.2), which is comparable to lowland forests in the African Tropical Rainforest Observation Network(4) and about 70 per cent and 32 per cent higher than averages from plot networks in montane(2,5,6) and lowland(7) forests in the Neotropics, respectively. Notably, our results are two-thirds higher than the Intergovernmental Panel on Climate Change default values for these forests in Africa(8). We find that the low stem density and high abundance of large trees of African lowland forests(4) is mirrored in the montane forests sampled. This carbon store is endangered: we estimate that 0.8 million hectares of old-growth African montane forest have been lost since 2000. We provide country-specific montane forest AGC stock estimates modelled from our plot network to help to guide forest conservation and reforestation interventions. Our findings highlight the need for conserving these biodiverse(9,10) and carbon-rich ecosystems. The aboveground carbon stock of a montane African forest network is comparable to that of a lowland African forest network and two-thirds higher than default values for these montane forests.Peer reviewe

Monoterpenoid extract of sage (Salvia lavandulaefolia) with cholinesterase inhibiting properties improves cognitive performance and mood in healthy adults

Extracts of sage (Salvia officinalis/lavandulaefolia) with terpenoid constituents have previously been shown to inhibit cholinesterase and improve cognitive function. The current study combined an in vitro investigation of the cholinesterase inhibitory properties and phytochemical constituents of a S. lavandulaefolia essential oil, with a double-blind, placebo-controlled, balanced crossover study assessing the effects of a single dose on cognitive performance and mood. In this latter investigation 36 healthy participants received capsules containing either 50 µL of the essential oil or placebo on separate occasions, 7 days apart. Cognitive function was assessed using a selection of computerized memory and attention tasks and the Cognitive Demand Battery before the treatment and 1-h and 4-h post-dose. The essential oil was a potent inhibitor of human acetylcholinesterase (AChE) and consisted almost exclusively of monoterpenoids. Oral consumption lead to improved performance of secondary memory and attention tasks, most notably at the 1-h post-dose testing session, and reduced mental fatigue and increased alertness which were more pronounced 4-h post-dose. These results extend previous observations of improved cognitive performance and mood following AChE inhibitory sage extracts and suggest that the ability of well-tolerated terpenoid-containing extracts to beneficially modulate cholinergic function and cognitive performance deserves further attention

Review of electrocardiographic abnormalities among people living with HIV in Sub-Saharan Africa: A systematic review

Introduction Electrocardiographic (ECG) abnormalities are increasingly being reported among people living with HIV (PLWH). However, the exact prevalence of ECG abnormalities among PLWH in Sub-Saharan Africa (SSA), a region with one of the highest burdens of HIV, is not known. Through a systematic review, we determined the prevalence and patterns of ECG abnormalities among PLWH in SSA. Methods We conducted a search in online databases including EMBASE, MEDLINE, CINAHL and Research for Life for studies published between 1st January 2000 and 31st December 2020. Studies reporting any form of ECG abnormalities published in English were screened and reviewed for eligibility. Retrieved studies were assessed for validity using the modified Newcastle-Ottawa Scale. Data was summarized qualitatively, and ECG abnormalities were further subcategorized into rate, conduction, and rhythm abnormalities as well as atrial and ventricular enlargements. Results We retrieved seventeen of the 219 studies assessed for eligibility published between 2001 and 2020, with a total of 2,572 eligible participants. The mean age of the participants ranged between 6.8 years and 58.6 years. Of the 17 studies, 8 (47%) were case-control, 6 (35.3%) cross-sectional and 3 (17.6%) were cohort in design. Thirteen studies were conducted in the adult population while four were conducted in the pediatric population. The prevalence of ECG abnormalities ranged from 10% to 81% and 6.7% to 26.5% in the adult and pediatric population respectively. Among studies done in the adult population, conduction abnormalities were the most reported (9 studies) with a prevalence ranging from 3.4% to 53.5%. In the pediatric population, rate abnormalities were the most reported (4 studies) with a prevalence ranging from 3.9% to 20.9%. The heterogeneity in results could be attributed to the absence of uniform criteria to define ECG abnormalities. Conclusion Our findings highlight a high prevalence of ECG abnormalities among PLWH in SSA. Consideration of ECG in the comprehensive evaluation of cardiac dysfunction among PLWH in SSA maybe warranted

Review of electrocardiographic abnormalities among people living with HIV in Sub-Saharan Africa: A systematic review.

IntroductionElectrocardiographic (ECG) abnormalities are increasingly being reported among people living with HIV (PLWH). However, the exact prevalence of ECG abnormalities among PLWH in Sub-Saharan Africa (SSA), a region with one of the highest burdens of HIV, is not known. Through a systematic review, we determined the prevalence and patterns of ECG abnormalities among PLWH in SSA.MethodsWe conducted a search in online databases including EMBASE, MEDLINE, CINAHL and Research for Life for studies published between 1st January 2000 and 31st December 2020. Studies reporting any form of ECG abnormalities published in English were screened and reviewed for eligibility. Retrieved studies were assessed for validity using the modified Newcastle-Ottawa Scale. Data was summarized qualitatively, and ECG abnormalities were further subcategorized into rate, conduction, and rhythm abnormalities as well as atrial and ventricular enlargements.ResultsWe retrieved seventeen of the 219 studies assessed for eligibility published between 2001 and 2020, with a total of 2,572 eligible participants. The mean age of the participants ranged between 6.8 years and 58.6 years. Of the 17 studies, 8 (47%) were case-control, 6 (35.3%) cross-sectional and 3 (17.6%) were cohort in design. Thirteen studies were conducted in the adult population while four were conducted in the pediatric population. The prevalence of ECG abnormalities ranged from 10% to 81% and 6.7% to 26.5% in the adult and pediatric population respectively. Among studies done in the adult population, conduction abnormalities were the most reported (9 studies) with a prevalence ranging from 3.4% to 53.5%. In the pediatric population, rate abnormalities were the most reported (4 studies) with a prevalence ranging from 3.9% to 20.9%. The heterogeneity in results could be attributed to the absence of uniform criteria to define ECG abnormalities.ConclusionOur findings highlight a high prevalence of ECG abnormalities among PLWH in SSA. Consideration of ECG in the comprehensive evaluation of cardiac dysfunction among PLWH in SSA maybe warranted

SCIP: software for efficient clinical interpretation of copy number variants detected by whole-genome sequencing

Abstract Copy number variants (CNVs) represent major etiologic factors in rare genetic diseases. Current clinical CNV interpretation workflows require extensive back-and-forth with multiple tools and databases. This increases complexity and time burden, potentially resulting in missed genetic diagnoses. We present the Suite for CNV Interpretation and Prioritization (SCIP), a software package for the clinical interpretation of CNVs detected by whole-genome sequencing (WGS). The SCIP Visualization Module near-instantaneously displays all information necessary for CNV interpretation (variant quality, population frequency, inheritance pattern, and clinical relevance) on a single page—supported by modules providing variant filtration and prioritization. SCIP was comprehensively evaluated using WGS data from 1027 families with congenital cardiac disease and/or autism spectrum disorder, containing 187 pathogenic or likely pathogenic (P/LP) CNVs identified in previous curations. SCIP was efficient in filtration and prioritization: a median of just two CNVs per case were selected for review, yet it captured all P/LP findings (92.5% of which ranked 1st). SCIP was also able to identify one pathogenic CNV previously missed. SCIP was benchmarked against AnnotSV and a spreadsheet-based manual workflow and performed superiorly than both. In conclusion, SCIP is a novel software package for efficient clinical CNV interpretation, substantially faster and more accurate than previous tools (available at https://github.com/qd29/SCIP , a video tutorial series is available at https://bit.ly/SCIPVideos )

Plasmodium ovale curtisi and Plasmodium ovale wallikeri circulate simultaneously in African communities☆

It has been proposed that ovale malaria in humans is caused by two closely related but distinct species of malaria parasite, Plasmodium ovale curtisi and Plasmodium ovale wallikeri. It was recently shown that these two parasite types are sympatric at the country level. However, it remains possible that localised geographic, temporal or ecological barriers exist within endemic countries which prevent recombination between the genomes of the two species. Here, using conventional and real-time quantitative PCR (qPCR) methods specifically designed to discriminate P. o. curtisi and P. o. wallikeri, it is shown that both species are present among clinic attendees in Congo-Brazzaville, and occur simultaneously both in lake-side and inland districts in Uganda and on Bioko Island, Equatorial Guinea. Thus P. o. curtisi and P. o. wallikeri in these localities are exactly sympatric in both time and space. These findings are consistent with the existence of a biological barrier, rather than geographical or ecological factors, preventing recombination between P. o. curtisi and P. o. wallikeri. In cross-sectional surveys carried out in Uganda and Bioko, our results show that infections with P. ovale spp. are more common than previously thought, occurring at a frequency of 1–6% in population samples, with both proposed species contributing to ovale malaria in six sites. Malaria elimination programmes in Africa need to include strategies for control of P. o. curtisi and P. o. wallikeri