Household biochar production and use by smallholder farmers in Kenya

About 40% of the world population lack access to clean cooking fuels. In rural sub-Saharan Africa the majority of people prepare their meals with firewood on open three stone fires. Biochar-producing microgasification cookstoves provide an opportunity to reduce fuel consumption and reduce the indoor air pollution in the cooking area, while use of biochar in soils sequesters carbon and increases agricultural yields, thereby improving livelihoods, especially for women. This paper presents findings from transdisciplinary research that started with long-term biochar field trials established in 2006. During recent years this research has involved 150 farming households at 3 locations in Kenya that produce biochar in locally manufactured GASTOV Top-lit Updraft (TLUD) gasifier cookstoves and use the biochar in their own fields. Fuel use, indoor concentrations of CO, CO2 and PM2.5 in cooking areas, and biochar production potential was measured in 75 households during cooking of a common Kenyan meal. The produced biochar was used in field trials with maize (Zea mays) and kale (Brassica oleracea) comparing biochar to normal farming practices, at biochar doses of 1-10 t ha-1. Findings from one of the sites, in Kwale County, show that for cooking a meal, on average 18 % of fuel was saved compared to the three stone open fire. In addition, 200 g biochar were produced which corresponded to 16.5% of the biomass used. Concentrations of CO and PM2.5 were reduced by 57 and 79 %, respectively. Fuel use was dominated by the wood types neem (Azadirachta indica) and casuarina (Casuarina equisetifolia), but a large variety of wood types were used by the households. Yield increases of maize in Kwale correlated positively with biochar dose. For the 20 farmers that finalized the trials in the first season, yields increased from 0.9 Mg ha-1 in the control plot to 4.4 Mg ha-1 in average in the biochar-amended plots. In addition to presentation of data on biochar production, we present data on biochar quality and use from all three sites. Implications and prerequisites for long-term success and upscaling will be discussed. This research contributes to knowledge on adoption of improved cookstoves by investigating how biochar production can be an additional incentive for cookstove uptake. Furthermore, it contributes to the understanding of biochar production potential in African rural areas. This case study shows that biochar systems in rural Africa can contribute to climate change mitigation. Biochar technology can at the same time help to solve the problems with energy and food security that farmers are facing, and thereby contribute to sustainable development

A prospective study of vaginal trichomoniasis and HIV-1 shedding in women on antiretroviral therapy

<p>Abstract</p> <p>Background</p> <p><it>Trichomonas vaginalis </it>has been associated with increased vaginal HIV-1 RNA shedding in antiretroviral therapy (ART)-naïve women. The effect of trichomoniasis on vaginal HIV-1 shedding in ART-treated women has not been characterized. We tested the hypothesis that <it>T. vaginalis </it>infection would increase vaginal HIV-1 RNA shedding in women on ART, and that successful treatment would reduce vaginal HIV-1 RNA levels.</p> <p>Methods</p> <p>We conducted a prospective cohort study including monthly follow-up of 147 women receiving ART in Mombasa, Kenya. Those with <it>T. vaginalis </it>infection, defined by the presence of motile trichomonads on vaginal saline wet mount, received treatment with single dose metronidazole (2 g). Test of cure was performed at the next monthly visit. Using the pre-infection visit as the reference category, we compared detection of vaginal HIV-1 RNA before versus during and after infection using generalized estimating equations. A cut-off of 100 HIV-1 RNA copies/swab was used as the lower limit for linear quantitation.</p> <p>Results</p> <p>Among 31 women treated for trichomoniasis, the concentration of vaginal HIV-1 RNA was above the limit for quantitation before, during, and after <it>T. vaginalis </it>infection in 4 (13% [95% CI 4% - 30%]), 4 (13% [95% CI 4% - 30%]), and 5 (16% [95% confidence interval {CI} 5% - 34%]) women respectively. After adjusting for potential confounding factors, we could detect no difference in the likelihood of detecting vaginal HIV-1 RNA before versus during infection (odds ratio [OR] 1.41, 95% CI 0.23 - 8.79, p = 0.7). In addition, detection of HIV-1 RNA was similar before infection versus after successful treatment (OR 0.68, 95% CI (0.13 - 3.45), p = 0.6).</p> <p>Conclusion</p> <p>Detection of vaginal HIV-1 RNA during ART was uncommon at visits before, during and after <it>T. vaginalis </it>infection.</p

It depends : Configuring AI to Improve Clinical Usefulness Across Contexts

Artificial Intelligence (AI) repeatedly match or outperform radiologists in lab experiments. However, real-world implementations of radiological AI-based systems are found to provide little to no clinical value. This paper explores how to design AI for clinical usefulness in different contexts. We conducted 19 design sessions and design interventions with 13 radiologists from 7 clinical sites in Denmark and Kenya, based on three iterations of a functional AI-based prototype. Ten sociotechnical dependencies were identified as crucial for the design of AI in radiology. We conceptualised four technical dimensions that must be configured to the intended clinical context of use: AI functionality, AI medical focus, AI decision threshold, and AI Explainability. We present four design recommendations on how to address dependencies pertaining to the medical knowledge, clinic type, user expertise level, patient context, and user situation that condition the configuration of these technical dimensions

Factors associated with occurrence of salmonellosis among children living in Mukuru slum, an urban informal settlement in Kenya

Abstract: Background: In Kenya, typhoid fever and invasive non-typhoidal salmonellosis present a huge burden of disease, especially in poor-resource settings where clean water supply and sanitation conditions are inadequate. The epidemiology of both diseases is poorly understood in terms of severity and risk factors. The aim of the study was to determine the disease burden and spatial distribution of salmonellosis, as well as socioeconomic and environmental risk factors for these infections, in a large informal settlement near the city of Nairobi, from 2013 to 2017. Methods: Initially, a house-to-house baseline census of 150,000 population in Mukuru informal settlement was carried out and relevant socioeconomic, demographic, and healthcare utilization information was collected using structured questionnaires. Salmonella bacteria were cultured from the blood and faeces of children < 16 years of age who reported at three outpatient facilities with fever alone or fever and diarrhea. Tests of association between specific Salmonella serotypes and risk factors were conducted using Pearson Chi-Square (χ2) test. Results: A total of 16,236 children were recruited into the study. The prevalence of bloodstream infections by Non-Typhoidal Salmonella (NTS), consisting of Salmonella Typhimurium/ Enteriditis, was 1.3%; Salmonella Typhi was 1.4%, and this was highest among children < 16 years of age. Occurrence of Salmonella Typhimurium/ Enteriditis was not significantly associated with rearing any domestic animals. Rearing chicken was significantly associated with high prevalence of S. Typhi (2.1%; p = 0.011). The proportion of children infected with Salmonella Typhimurium/ Enteriditis was significantly higher in households that used water pots as water storage containers compared to using water directly from the tap (0.6%). Use of pit latrines and open defecation were significant risk factors for S. Typhi infection (1.6%; p = 0.048). The proportion of Salmonella Typhimurium/ Enteriditis among children eating street food 4 or more times per week was higher compared to 1 to 2 times/week on average (1.1%; p = 0.032). Conclusion: Typhoidal and NTS are important causes of illness in children in Mukuru informal settlement, especially among children less than 16 years of age. Improving Water, Sanitation and Hygiene (WASH) including boiling water, breastfeeding, hand washing practices, and avoiding animal contact in domestic settings could contribute to reducing the risk of transmission of Salmonella disease from contaminated environments

Calf health and management in smallholder dairy farms in Tanzania

Smallholder farmers’ knowledge and practice of dairy calf management on 129 farms with calves less than 10 months of age in Southeastern and Southern Highland areas of Tanzania was assessed. The method of study included both a farm visit and completion of a questionnaire. Most of the farmers were female, with a primary level of education, and majority kept 1–3 milking cows that yielded 6–10 l milk/cow/day. Most of the calves were fed milk using a residual calf suckling system. Weaning age was 3–8 months. Overall, the body condition of the calves was poor, ranged from 1 to 2.5 with a mode of 2. The majority of the farmers believed that helminthosis was the most common disease condition affecting the calves; diarrhea was ranked as the second. Calf death was reported by 20% of the farmers to have occurred in their herd lasting the 2 years prior to the study. Calf body condition score was related to body weight for calves younger than 9 weeks, and older than 23 weeks of age, whereas no such relationship existed in the age group 9 to 23 weeks. The sex distribution was skewed with less male calves being older than 23 weeks. We hypothesize that male calves experience inferior management compared with female calves. This study demonstrates a low level of knowledge on, and poor practices of calf management among the surveyed farmers that suggest the need for educational intervention

Factors associated with occurrence of salmonellosis among children living in Mukuru slum, an urban informal settlement in Kenya

Abstract: Background: In Kenya, typhoid fever and invasive non-typhoidal salmonellosis present a huge burden of disease, especially in poor-resource settings where clean water supply and sanitation conditions are inadequate. The epidemiology of both diseases is poorly understood in terms of severity and risk factors. The aim of the study was to determine the disease burden and spatial distribution of salmonellosis, as well as socioeconomic and environmental risk factors for these infections, in a large informal settlement near the city of Nairobi, from 2013 to 2017. Methods: Initially, a house-to-house baseline census of 150,000 population in Mukuru informal settlement was carried out and relevant socioeconomic, demographic, and healthcare utilization information was collected using structured questionnaires. Salmonella bacteria were cultured from the blood and faeces of children < 16 years of age who reported at three outpatient facilities with fever alone or fever and diarrhea. Tests of association between specific Salmonella serotypes and risk factors were conducted using Pearson Chi-Square (χ2) test. Results: A total of 16,236 children were recruited into the study. The prevalence of bloodstream infections by Non-Typhoidal Salmonella (NTS), consisting of Salmonella Typhimurium/ Enteriditis, was 1.3%; Salmonella Typhi was 1.4%, and this was highest among children < 16 years of age. Occurrence of Salmonella Typhimurium/ Enteriditis was not significantly associated with rearing any domestic animals. Rearing chicken was significantly associated with high prevalence of S. Typhi (2.1%; p = 0.011). The proportion of children infected with Salmonella Typhimurium/ Enteriditis was significantly higher in households that used water pots as water storage containers compared to using water directly from the tap (0.6%). Use of pit latrines and open defecation were significant risk factors for S. Typhi infection (1.6%; p = 0.048). The proportion of Salmonella Typhimurium/ Enteriditis among children eating street food 4 or more times per week was higher compared to 1 to 2 times/week on average (1.1%; p = 0.032). Conclusion: Typhoidal and NTS are important causes of illness in children in Mukuru informal settlement, especially among children less than 16 years of age. Improving Water, Sanitation and Hygiene (WASH) including boiling water, breastfeeding, hand washing practices, and avoiding animal contact in domestic settings could contribute to reducing the risk of transmission of Salmonella disease from contaminated environments

Understanding users' needs is important for the adoption of cleaner biomass cook stoves

elwood is the main source of cooking and heating energy for households in rural sub-Saharan Africa. Unfortunately, most of these households use inefficient biomass cook stoves, leading to consumption of more fuel and exposure to indoor air pollutants and associate health problems which disproportionately affect women and children. However, adoption of cleaner biomass cook stoves has remained low which could be associated to low understanding of users' needs and preferences among other factors. This study examined the performance and use of efficient gasifier cook stoves in the mid-lowlands, highlands and coastal regions of Kenya. Gasifier stoves that produce char (charcoal when used fuel or biochar when used for soil amendment) while cooking were issued to 150 households for free and their performance in fuel use and household air pollution in real life assessed among 50% of the households using participatory cooking tests. Further uptake surveys were carried out after 2–3 months about one year after gasifier cook stoves were issued. The gasifier performs better than three-stone open fire as it reduces fuel use by 51% and 28% when char is considered as fuel and biochar for soil amendment respectively. The new stove reduces concentration of PM2.5 and CO by 90% and 73% respectively. The results showed that after 2-3 months, 86%, 96% and 100% (average 94%) of households were using the stove though at varying frequencies of 4, 9 and 7 (average 7) times per week in Embu, Kwale and Siaya respectively. The use of the new stove was alongside their traditional stoves a common practice known as stove stacking. The gasifier was mainly used to cook foods that required a short cooking time and many preferred to use it to cook dinner. After about one year, 38%, 100 % and 88% (average 75%) of households were using it 3, 2 and 5 (average 3) times per week in Embu, Kwale and Siaya respectively while stove stacking. The surveys showed that the users liked the gasifier because it saves fuel, produce char used as charcoal providing fuel for other purposes such as ironing clothes and heating space, cook well and burn longer with less smoke and is easy to harvest and cool the char produced. However, despite the positive characteristics the users found it difficult to light from the top, chop wood into required sizes and reload the stove when fuel charred before the food got ready. To meet their cooking and heating needs, households continued to use the traditional three-stone and added the new stove. Users’ needs and preferences need to be understood and considered in the development of cleaner cooking biomass stoves for enhanced adoption and realization of the associated benefit

Comparative Assessment of Gasifier Cookstove Performance on Smallholder Farms in Three Regions in Kenya

A majority of households in sub-Saharan Africa use inefficient biomass stoves in poorly ventilated kitchens, leading to indoor air pollution. Biomass for cooking can be sustainably sourced from agricultural residues such as prunings from agroforestry. This study assessed biochar-producing gasifier cookstove performance among 150 households in Embu, Kwale, and Siaya Counties through household surveys and participatory cooking tests with 75 households. With the gasifier, carbon monoxide (CO) concentrations were lower in Embu (5.1 ppm), while carbon dioxide (CO2) and fine particulate matter (PM2.5) were lower in Kwale, at 588 ppm and 136 &mu;g/m3, respectively. Compared to the three-stone open fire, reductions in CO and PM2.5 concentrations were highest in Embu, at 82% and 97%, respectively. The biomass-to-char conversion efficiency with the gasifier was 17&ndash;18%. If households consider the produced char as a soil amendment, they could save 24&ndash;43% of fuel compared to the three-stone open fire; if the char is seen as fuel, the potential savings are 42&ndash;65%. Significant differences between the three sites were observed with the gasifier for gross and net fuel use, and for concentrations of PM2.5 and CO2. Gasifier uptake can reduce the need for fuel collection and indoor air pollution, with a positive impact on both the environment and human wellbeing

Implications on Livelihoods and the Environment of Uptake of Gasifier Cook Stoves among Kenya’s Rural Households

A majority of people in developing countries use biomass energy for cooking and heating due to its affordability, accessibility and convenience. However, unsustainable biomass use leads to forest degradation and climate change. Therefore, this study was carried out in Kwale County, Kenya, on the use of a biochar-producing gasifier cook stove and implications of its uptake on livelihoods and the environment. Fifty households were trained and issued with a gasifier for free. After 2–3 months of gasifier use, a survey was conducted to investigate the implications of its uptake. The direct impacts included reduced fuel consumption by 38%, reduced time spent in firewood collection, reduced expenditure on cooking fuel, diversification of cooking fuels, improved kitchen conditions and reduced time spent on cooking. The potential benefits included income generation, increased food production, reduced impacts on environment and climate change and reduced health problems. Improved biomass cook stoves can alleviate problems with current cooking methods, which include inefficient fuel use, health issues caused by smoke, and environmental problems. These benefits could contribute to development through alleviating poverty and hunger, promoting gender equality, enhancing good health and sustainable ecosystems and mitigating climate change. The study recommends the promotion of cleaner cooking stoves, particularly gasifiers, among households in rural areas while paying attention to user needs and preferences.</jats:p

Implications on Livelihoods and the Environment of Uptake of Gasifier Cook Stoves among Kenya’s Rural Households

A majority of people in developing countries use biomass energy for cooking and heating due to its affordability, accessibility and convenience. However, unsustainable biomass use leads to forest degradation and climate change. Therefore, this study was carried out in Kwale County, Kenya, on the use of a biochar-producing gasifier cook stove and implications of its uptake on livelihoods and the environment. Fifty households were trained and issued with a gasifier for free. After 2–3 months of gasifier use, a survey was conducted to investigate the implications of its uptake. The direct impacts included reduced fuel consumption by 38%, reduced time spent in firewood collection, reduced expenditure on cooking fuel, diversification of cooking fuels, improved kitchen conditions and reduced time spent on cooking. The potential benefits included income generation, increased food production, reduced impacts on environment and climate change and reduced health problems. Improved biomass cook stoves can alleviate problems with current cooking methods, which include inefficient fuel use, health issues caused by smoke, and environmental problems. These benefits could contribute to development through alleviating poverty and hunger, promoting gender equality, enhancing good health and sustainable ecosystems and mitigating climate change. The study recommends the promotion of cleaner cooking stoves, particularly gasifiers, among households in rural areas while paying attention to user needs and preferences