Publications

This study investigates the effect of varying cost and process parameters on bioethanol production rate and the minimum bioethanol selling price (MBSP) during large-scale production of second-generation bioethanol from Sila sorghum stalks found in Kenya. Aspen Plus was used to model and simulate the process that was considered in this study. The flow rate of biomass was varied between 10,000 and 300,000 kg/h which gave rise to a bioethanol flow rate of between 2134.49 and 62,707.33 kg/h. Bioethanol production rate decreased from 21,759.5 to 19,397.6 kg/h when the feed stage position in the beer column increased from 2 to 8. MBSP increased from $0.81/L to $1.11/L when the cost of biomass was varied from $20/tonne to $100/tonne. MBSP increased from $0.9/L to $1.0/L when the cost of enzymes was varied by − 50% and + 50%. MBSP increased from $0.83/L to $1.54/L when discount rate varied by 5% and 30%. MBSP increased from $0.85/L to $1.06/L when fixed capital investment was varied by -35% and + 35%. MBSP reduced from $1.28/L to $0.95/L when plant life varied from 10 to 30 years. MBSP increased from $0.89/L to $0.99/L when income tax rate varied from 0 to 40%. The study indicates that second-generation bioethanol is able to compete with gasoline in Kenya when no levies and taxes are imposed on the MBSP, at a plant life of 15 years and beyond and at an income tax rate of between 0 to 40%.

BACKGROUND: Abacavir is a nucleoside reverse transcriptase inhibitor that is used as a component of the antiretroviral treatment regimen in the management of the human immunodeficiency virus for both adults and children. It is efficacious, but its use may be limited by a hypersensitivity reaction linked with the HLA-B*57:01 genotype. HLA-B*57:01 has been reported to be rare in African populations. Because of the nature of its presentation, abacavir hypersensitivity is prone to late diagnosis and treatment, especially in settings where HLA-B*57:01 genotyping is not routinely done. CASE REPORT: We report a case of a severe hypersensitivity reaction in a 44-year-old Kenyan female living with the human immunodeficiency virus and on abacavir-containing antiretroviral therapy. The patient presented to the hospital after recurrent treatment for a throat infection with complaints of fever, headache, throat ache, vomiting, and a generalized rash. Laboratory results evidenced raised aminotransferases, for which she was advised to stop the antiretrovirals that she had recently been started on. The regimen consisted of abacavir, lamivudine, and dolutegravir. She responded well to treatment but was readmitted a day after discharge with vomiting, severe abdominal pains, diarrhea, and hypotension. Her symptoms disappeared upon admission, but she was readmitted again a few hours after discharge in a hysterical state with burning chest pain and chills. Suspecting abacavir hypersensitivity, upon interrogation she reported that she had taken the abacavir-containing antiretrovirals shortly before she was taken ill. A sample for HLA-B*57:01 was taken and tested positive. Her antiretroviral regimen was substituted to tenofovir, lamivudine, and dolutegravir, and on subsequent follow-up she has been well. CONCLUSIONS: Clinicians should always be cognizant of this adverse reaction whenever they initiate an abacavir-containing therapy. We would recommend that studies be done in our setting to verify the prevalence of HLA-B*57:01.

The up-surging population in sub-Saharan Africa (SSA) has led to the conversion of more land for agricultural purposes. Resilient land utilization types that input carbon to the soil are key in enhancing climate change mitigation. However, there are limited data on different land utilization types’ contribution to climate mitigation through carbon input to soils. The study aims to quantify carbon stock across different land utilization types (LUT) practiced in Western Kenya. The following land utilization types were studied: agroforestry M (agroforestry with Markhamia lutea), sole sorghum, agroforestry L (agroforestry with Leucaena leucocephalaI), sole maize, and grazing land replicated thrice. To determine soil bulk density, SOC concentration, and soil carbon stock, soil samples were collected at depths of 0–5, 5–10, 10–20, and 20–30 cm from different LUTs. A PROC ANOVA was used to determine the difference in soil bulk density, SOC, and SOC stock between different LUTs and depths. The four variables differed across the LUTs and depths. A high soil bulk density was observed at 0–5 cm under grazing land (1.6 g cm−3) and the lowest under agroforestry M (1.30 g cm−3). Conversely, the soil bulk density was low at 20–30 cm under grazing land. The 0–5 cm depth accounted for a high share of SOC and SOC stock under Agroforestry M, while the 10–20 and 20–30 cm depth accounted for the high share of SOC stock under agroforestry L. The study showed differences in SOC across the different depths and LUTs. The findings highlight that agroforestry L and agroforestry M are promising interventions toward climate mitigation through carbon induction to soils.