Addressing post-harvest losses during traditional banana fermentation for increased food security in Southwest Uganda

Postharvest losses (PHL) destroy 20-60% of the food production in East Africa, exacerbating already severe regional food insecurity. Fermenting perishable foods such as fruits may reduce PHL while providing nutritional enrichment, improving shelf-life and food quality, and addressing seasonality in food supply. Fermented banana products have been refined and diversified in Uganda over generations to make the greatest use of available food resources, but still parts of the raw material are being lost during processing. This study aimed at exploring existing traditional methods and efficiency of fermentation of Musa (AAA-EAHB) 'Mbidde' in southwestern Uganda. The study gathered information through participatory explorations (working with brewers) on banana juice (lightly fermented beer with <1% alcohol content [n=20 brewers]), tonto (turbid beer with ~4% alcohol [n=20]), and amarwa (smoky spirit with ~ 40% alcohol [n=20]). Brewers mentioned several losses of material during harvest and processing. Harvesting bananas requires felling the plant causing ripe fruit damage, particularly during harvest for processing banana juice (loss from fresh bananas=6.4%±8.8%) or amarwa (loss=9.3%±9.5%). Second, losses occur when brewers squeeze juice from the raw banana pulp using stems of Imperata cylindrica, which is then discarded or fed to animals together with the adherent fruit pulp (losses from raw banana juice=50.6%±0.2%; from tonto 39.2%±21.4% and amarwa 47.6%±12.5%). Other causes of PHL during processing are excessive peeling for tonto processing (loss of banana flesh=18.6%±5.8%) and losses of intermediate products during distillation of amarwa (loss=75.9%±1.3%). Total losses of banana products during processing were rare and caused by sabotage (mostly by children), mistakes in the brewing process (e.g. addition of too much water), using bananas of wrong ripening stage, and equipment failure (e.g., burst or leaking drums in distillation equipment). Other non-PHL challenges include Banana Xanthomonas Wilt (BXW) and bad weather (up to 50% losses in the field). Despite the general efficiency of traditional fermentation practices, significant portions of fruit are still lost. Reduction in PHL can complement, both culturally and nutritionally, the role that fermented banana products play in Ugandan food systems and contribute to regional food security. Collaborative mechanisms for PHL reduction should target the cited sources of PHL

From thermal rectifiers to thermoelectric devices

We discuss thermal rectification and thermoelectric energy conversion from the perspective of nonequilibrium statistical mechanics and dynamical systems theory. After preliminary considerations on the dynamical foundations of the phenomenological Fourier law in classical and quantum mechanics, we illustrate ways to control the phononic heat flow and design thermal diodes. Finally, we consider the coupled transport of heat and charge and discuss several general mechanisms for optimizing the figure of merit of thermoelectric efficiency.Comment: 42 pages, 22 figures, review paper, to appear in the Springer Lecture Notes in Physics volume "Thermal transport in low dimensions: from statistical physics to nanoscale heat transfer" (S. Lepri ed.

Virologic Failure Among People Living With HIV Initiating Dolutegravir-Based Versus Other Recommended Regimens in Real-World Clinical Care Settings

Background: Guidelines for initial antiretroviral treatment (ART) regimens have evolved, with integrase strand transfer inhibitors (INSTIs) increasingly prominent. Research on virologic failure (VF) with INSTI therapy is predominantly from clinical trials not care settings, especially for recently approved medications including dolutegravir. We compared outcomes among people living with HIV (PLWH) who initiated recommended regimens in clinical care across the United States. Setting: We examined 2 groups of PLWH at 8 clinics who initiated ART regimens (August 1, 2013-March 31, 2017): those ART treatment-naive at initiation, and those treatment-experienced. Methods: The outcome in this longitudinal cohort study was VF, defined as a viral load of ≥400 copies/mL ≥6 months after ART initiation. We examined the proportion of individuals who remained on, switched, or discontinued the regimen. Associations between regimens and outcomes were examined with adjusted Cox proportional hazards models. Results: Among 5177 PLWH, a lower proportion experienced VF on dolutegravir- versus other INSTI- or darunavir-based regimens for previously treatment-naive (7% vs. 12% vs. 28%) and treatment-experienced PLWH (6% vs. 10% vs. 21%). In adjusted analyses, hazard ratios were similar across regimens for the combined outcome of regimen discontinuation or treatment switch. The hazard ratios for VF comparing dolutegravir- to darunavir-based regimens was 0.30 (95% CI: 0.2 to 0.6) among previously treatment-naive PLWH and was 0.60 (95% CI: 0.4 to 0.8) among treatment-experienced PLWH. Conclusions: The proportion of previously treatment-naive PLWH remaining on recommended ART regimens did not differ by regimen. The likelihood of VF was lower with dolutegravir- than darunavir-based regimens for previously treatment-naive and treatment-experienced PLWH

Post-acute COVID-19 neuropsychiatric symptoms are not associated with ongoing nervous system injury

A proportion of patients infected with severe acute respiratory syndrome coronavirus 2 experience a range of neuropsychiatric symptoms months after infection, including cognitive deficits, depression and anxiety. The mechanisms underpinning such symptoms remain elusive. Recent research has demonstrated that nervous system injury can occur during COVID-19. Whether ongoing neural injury in the months after COVID-19 accounts for the ongoing or emergent neuropsychiatric symptoms is unclear. Within a large prospective cohort study of adult survivors who were hospitalized for severe acute respiratory syndrome coronavirus 2 infection, we analysed plasma markers of nervous system injury and astrocytic activation, measured 6 months post-infection: neurofilament light, glial fibrillary acidic protein and total tau protein. We assessed whether these markers were associated with the severity of the acute COVID-19 illness and with post-acute neuropsychiatric symptoms (as measured by the Patient Health Questionnaire for depression, the General Anxiety Disorder assessment for anxiety, the Montreal Cognitive Assessment for objective cognitive deficit and the cognitive items of the Patient Symptom Questionnaire for subjective cognitive deficit) at 6 months and 1 year post-hospital discharge from COVID-19. No robust associations were found between markers of nervous system injury and severity of acute COVID-19 (except for an association of small effect size between duration of admission and neurofilament light) nor with post-acute neuropsychiatric symptoms. These results suggest that ongoing neuropsychiatric symptoms are not due to ongoing neural injury

Large-scale phenotyping of patients with long COVID post-hospitalization reveals mechanistic subtypes of disease

One in ten severe acute respiratory syndrome coronavirus 2 infections result in prolonged symptoms termed long coronavirus disease (COVID), yet disease phenotypes and mechanisms are poorly understood1. Here we profiled 368 plasma proteins in 657 participants ≥3 months following hospitalization. Of these, 426 had at least one long COVID symptom and 233 had fully recovered. Elevated markers of myeloid inflammation and complement activation were associated with long COVID. IL-1R2, MATN2 and COLEC12 were associated with cardiorespiratory symptoms, fatigue and anxiety/depression; MATN2, CSF3 and C1QA were elevated in gastrointestinal symptoms and C1QA was elevated in cognitive impairment. Additional markers of alterations in nerve tissue repair (SPON-1 and NFASC) were elevated in those with cognitive impairment and SCG3, suggestive of brain–gut axis disturbance, was elevated in gastrointestinal symptoms. Severe acute respiratory syndrome coronavirus 2-specific immunoglobulin G (IgG) was persistently elevated in some individuals with long COVID, but virus was not detected in sputum. Analysis of inflammatory markers in nasal fluids showed no association with symptoms. Our study aimed to understand inflammatory processes that underlie long COVID and was not designed for biomarker discovery. Our findings suggest that specific inflammatory pathways related to tissue damage are implicated in subtypes of long COVID, which might be targeted in future therapeutic trials

Agrobiodiversity and nutrition in traditional cropping systems - Homegardens of the indigenous Bakiga and Banyakole in southwestern Uganda.

In Uganda many farmer households have diverse agroforestry systems known as homegardens, which have been adapted over generations to supply a year-round harvest of nutritious foods. The work presented in this dissertation sought to identify the factors that influence the agrobiodiversity of these homegardens and to assess the effects of that agrobiodiversity on the health of the households that keep them. Households (n=102) were identified via stratified, random selection across three distinct regional ecological zones of southwestern Uganda (forest-edge, deforested areas, and wetland-edge). Their homegardens contained 209 (mean 26.8 per homegarden) useful crop species (excluding weeds and ornamentals). Crop diversity response variables regressed against socio-economic and bio-physical predictor variables, indicated weak but significant relationships (Adjusted R2 between 12 to 42%, p<0.001), the significant predictors included elevation, location, garden size, distance to market, additional land ownership (beyond the homegarden) and livestock ownership. Elevation, location and garden size also differed between four garden types, identified by cluster analysis (39 ‘Diverse tree gardens’, 10 ‘Small forest-edge gardens’, 10 ‘Large, old, species-rich gardens’, and 43 ‘Large, annual-dominated herb gardens’). Further agrobiodiversity studies with quantitative ethnobotany of 225 useful plant species (including ornamentals and weeds with secondary uses) revealed 3,961 use reports, 54% for food, 15% for economic uses and 11% for medicine. During related surveys of flora throughout the country, the baobab (Adansonia digitata L.) was recorded in a homegarden in the east, changing the current scientific knowledge of homegarden agrobiodiversity in Uganda. The agrobiodiversity data from homegardens in southwestern Uganda were compared with multiple- pass 24-hour recalls, anthropometric measurements and food insecurity questionnaires of households (n=589, 325 and 95 respectively). Results indicated positive relationships between homegarden agrobiodiversity and health outcomes. Regression models explained between 16 and 50% of variance in dietary diversity and between 21 and 75% in anthropometric measurements. Probabilistic Monte Carlo analysis was used to predict the nutrition implications of the country’s development plan to industrialize agriculture, versus maintaining homegardens. Results revealed that industrial farms produce more carbohydrate-based food energy, but that homegardens produce more key vitamins and micronutrients. The holistic and uncertainty-embracing approaches presented in this dissertation should be used to inform agricultural development decisions, especially given the data scarcity in East Africa