Aneth David | University of Dar es Salaam (original) (raw)

Papers by Aneth David

Background Leishmaniasis as many Neglected Tropical Diseases conditions is prevalent in impoveris... more Background Leishmaniasis as many Neglected Tropical Diseases conditions is prevalent in impoverished communities in tropical and subtropical areas across Africa, Asia, and Latin America. Leishmaniasis is a vector-borne disease caused by different species of protozoan parasites of the genus Leishmania. Approximately 90 sandfly species have been associated with the transmission of more than 90 Leishmania species with approximately 350 million people at risk and more than 2 million infections occurring worldwide annually. Methods This study employs bibliometric and visual analysis to explore trends in leishmaniasis research, aiming to identify research themes, hotspots, and future development trends. The search strategy used in the Scopus database was ["leishmaniasis" OR "Leishmania" OR "leishmania infection" in all fields] from 2010 until 30 th March 2023. Neither language nor document type restriction was employed during the search and information analysis. Results

Low-and middle-income countries face obstacles in sharing scientific research globally due to cos... more Low-and middle-income countries face obstacles in sharing scientific research globally due to costly publishing fees and biases. Preprints-manuscripts shared before formal journal-organised peer review-offer a potential remedy. However, their uptake, mainly in the USA, UK, and Western Europe, contrasts sharply with limited adoption in Africa. Understanding African researchers' views on preprints remains scant, hindering acceptance. Our survey reveals widespread unawareness regarding preprints and reliance on traditional publishers among African researchers. Of 182 respondents from Nigeria, South Africa, and Tanzania, 41.9% posted preprints, yet 77% were unaware of Africa-specific repositories. While non-posters read preprints, fewer cited or shared them. Social media served as the primary platform for preprint sharing, with concerns over sharing before peer review. Although recognized for accessibility and career enhancement, concerns persisted regarding recognition and co-author unfamiliarity. Encouragement from publishers was vital, but opinions varied on institutional and funder involvement, highlighting differing perceptions in promoting preprints. Additionally, our data suggests that traditional publishers dominate the preprint landscape for Africa-based researchers. This study provides important preliminary information relating to perceptions of preprints across African scholars and highlights the need for urgent further work to increase awareness and adoption of preprints across Africa.

Continued growth of oil palm cultivation for palm oil production has led to higher post-processin... more Continued growth of oil palm cultivation for palm oil production has led to higher post-processing wastes that pose environmental management challenges. The goal of this study was to investigate the co-production of oyster mushroom Pleurotus HK-37 and biogas as a means to add value to palm oil waste fractions and thus reduce their impact on the environment. A total of 9 blends of solid, semi-solid and liquid palm oil waste fractions were subjected to mushroom production and the resulting spent mushroom substrate (SMS) was used for biogas production. There was a significant difference in mushroom yield (t-test, p = 0.00013237) and biological efficiency (t-test, p = 0.00044955), with the highest values obtained from substrate formulation no. 3 (1:1 PMF and EFB (each 49% total weight) supplemented with POME and SD at 1%). Biogas production was also significantly different among both fresh and pretreated (SMS) waste fractions. The highest biogas volume, methane content and methane yield were observed from SMS waste fractions no. 4 (1:1 PMF and EFB (each 44% total weight) supplemented with PPC and PKS at 5% and POME and SD at 1%). Overall, pretreatment of palm oil processing waste with oyster mushrooms increased biogas production and methane yield per kg volatile solids by 102.78% compared to untreated waste. This study has demonstrated that mushroom and biogas production are viable options for the management of palm oil processing waste fractions and thus promoting a circular economy. Further studies should optimize their production and conduct techno-economic Qeios, CC-BY 4.0 • Article,

Rare diseases (RDs) affect a small proportion of the population when compared to infectious and n... more Rare diseases (RDs) affect a small proportion of the population when compared to infectious and non-communicable diseases (NCDs) and thus receive limited attention. However, there are more than 10,000 known RDs affecting about 300 million people worldwide. The majority of rare diseases are hereditary and affect children. RDs are understudied and are difficult to diagnose, manage, and treat. The situation is worse in sub-Saharan Africa (SSA), where the public health infrastructure is weak, leaving a high health and cost burden on patients and caretakers. SSA is yet to adopt a common definition of what constitutes a rare disease as other regions, let alone establish the demographics of the kinds of RDs afflicting the population and the actual burden. Furthermore, policy frameworks and instruments to guide the management of RDs are non-existent. This gap contributes to a slow pace in the realization of universal healthcare and the sustainable development goals in this region.

Due to the insufficient human and infrastructure capacity to use novel genomics and bioinformatic... more Due to the insufficient human and infrastructure capacity to use novel genomics and bioinformatics technologies, Sub-Saharan Africa countries have not entirely ripped the benefits in health and other sectors. The main objective of this study was to map out the interest and capacity for conducting bioinformatics and related research in Tanzania. The survey collected demographic information like age group, experience, seniority level, gender, number of respondents per institution, number of publications, and willingness to join the community of practice. The survey also investigated the capacity of individuals and institutions about computing infrastructure, operating system use, statistical packages in use, the basic Microsoft packages experience, programming language experience, bioinformatics tools and resources usage, and type of analyses performed. Moreover, respondents were surveyed about the challenges they faced in implementing bioinformatics and their willingness to join the bioinformatics community of practice in Tanzania. This dataset contains survey response data, supplementary tables and the data instrument (Questionnaire) used in the survey. In addition, a data dictionary is attached containing the map of all the 113 variables used in this survey. The total number of questions in the questionnaire was 54, but for multiple-choice questions, the variables were replicated per the number of options.

bioRxiv (Cold Spring Harbor Laboratory), Feb 9, 2023

Introduction: Several Desmodium spp. are used as intercrops in push-pull pest management systems ... more Introduction: Several Desmodium spp. are used as intercrops in push-pull pest management systems to repel insect herbivores. In addition, Desmodium suppresses the parasitic weed Striga, and diversifies the soil microbiome with negative impacts on fungi. We investigated the impact of a 2-year cropping of five Desmodium species on soil microbiome populations. Methodology: Total DNA was obtained from root zone soil samples collected from a twoyears-old common garden experiment with replicated plots of five Desmodium spp. at the international centre for insect physiology and ecology (ICIPE), Mbita, Kenya. Subsequently, 16S and ITS DNA sequencing were performed and the data was analysed by using QIIME2 and Calypso. Results: Our findings show significant differences in composition and abundance of specific microbial taxa among the Desmodium plots and the bulk soil, with a stronger shift observed for fungal community profiles than bacteria. There was, however, no significant difference in overall diversity, richness and evenness of microbial communities among the Desmodium plots and the bulk soil. Similarly, beta diversity analysis did not reveal a significant association of variation to specific Desmodium spp. plots. Discussion and conclusion: This is the first study to compare impact and association of whole soil microbiomes to different Desmodium species. Whereas long-term Desmodium cropping clearly shifts whole microbiome communities, no significant difference in overall diversity and richness of microbial populations was observed among the studied plots. However, there was a divergence of individual taxa reflected on their increased abundance in association to specific Desmodium spp., pointing towards potential impact on ecosystem services. These findings indicate that significant shifts in whole microbial populations due to Desmodium spp. and thus potentially provision of associated ecosystem services require longer cultivation periods to solidify. Future studies should focus on techniques that monitor real-time changes in microbial populations such as RNA-seq to ascertain live and dead microbes, and thus infer ecological services.

The Open Science (OS) movement has been spreading rapidly among researchers with positive outcome... more The Open Science (OS) movement has been spreading rapidly among researchers with positive outcomes on accessibility of scientific knowledge. However, there is no clear evidence on the level of awareness and types of OS practices among scholars and researchers in Tanzania, potentially missing an opportunity to reap the rewards of the movement to scholarly pursuits. This study investigated the level of awareness of OS and practices among Tanzanian scholars and researchers. Findings of a digital survey conducted for three months and recruited 144 respondents, show a high level of awareness of the term OS for 84% of respondents, most of them having encountered it from peers or online sources including social media. About 69% of respondents were male while about 44% of respondents were early career professionals. Open access (OA) publishing was the most common OS activity practised by respondents, highlighting both the need to create awareness on other practices and an entry point for kn...

Purpose: Push-pull is an intercropping technology that rapidly spreads among Sub-Saharan smallhol... more Purpose: Push-pull is an intercropping technology that rapidly spreads among Sub-Saharan smallholder farmers. It intercrops maize with Desmodium to fight off stem borers, eliminate parasitic weeds, and improve soil fertility and yields. The above-ground components of push-pull cropping have been well investigated. However, impact on and from the soil microbiome and its role in diverse ecosystem benefits are unknown. Here we describe the soil microbiome associated with push-pull and compare it with maize monoculture.Methods: Soil samples from long-term maize-desmodium intercropping and maize monoculture plots were analysed using 16S and ITS metagenomics.Results: Maize-desmodium intercropping caused a strong divergence in fungal microbiome, which was more diverse and species rich than monoculture plots. Zooming into genera revealed that intercropping enhanced fungal genera linked to important ecosystem services. These include mycorrhizal and endophytic groups such as Edenia, Acrocalym...

Orphanet Journal of Rare Diseases

A rare disease is generally defined as a condition which affects about 1 among 2000 people and cu... more A rare disease is generally defined as a condition which affects about 1 among 2000 people and currently, there are approximately 5000–8000 rare diseases (RDs) affecting over 400 million people world-wide. Although RDs may arise from different causes such as infections and environmental factors, about 80% are caused by genetic abnormalities. In Tanzania, there are no reports of the types of RDs, their incidence, distribution and numbers of individuals affected. In addition, there have been no strategies to map RDs in the country and develop a definition that fits the local context. Public awareness and understanding of RDs are very limited, and these lead to poor management and stigmatisation of patients. To address the ongoing problems, Tanzania joined other countries world-wide and global partners to commemorate the rare diseases day (RDD) for the first time in 2016 and subsequently every year. Unlike previous years where the RDD was organised by Ali Kimara Rare Diseases Foundatio...

Over two decades ago, scientists developed a push-pull intercropping strategy that received criti... more Over two decades ago, scientists developed a push-pull intercropping strategy that received critical acclaim for synergizing food security with ecosystem resilience in smallholder farming. The strategy suppresses Lepidopteran pests in maize through a combination of a repellent intercrop (push), commonly Desmodium spp., and an attractive, dead-end border crop (pull). Key is the intercrop’s constitutive release of volatiles that repel herbivores. Surprisingly, however, we found that Desmodium does not constitutively release volatiles, and only minimally upon herbivory. Further, in oviposition choice settings, Spodoptera frugiperda, a devastating invasive pest, was not repelled by Desmodium volatiles. In search of an alternative mechanism, we found that neonate larvae strongly preferred Desmodium over maize. However, their development stagnated and none survived. In addition, larvae were frequently seen impaled and immobilized by the dense network of silica-fortified, non-glandular tri...

Current estimates show that there are approximately 6000-8000 rare Diseases (RDs) which affect ov... more Current estimates show that there are approximately 6000-8000 rare Diseases (RDs) which affect over 300 million people worldwide. Individually, each RD affects <200,000 people mainly children because of limited survival, leaving a lifetime/life changing impact on affected individuals. Most RDs have a genetic origin, however the underlying causes and mechanisms of most RDs are still largely unknown. In Tanzania, there is limited data on incidence, distribution and types of RDs. In addition, there is little awareness and understanding of RDs by the public, which has resulted in poor management and stigmatization of individuals with RDs. To address this problem, a RD day is commemorated globally every February with the aim of raising awareness among the general public and decision makers about RDs and their impacts on individuals' lives. In addition, this platform is normally used to put emphasis on improvement and access to healthcare for affected individuals. From 2008 to 2020, the RD Day has been commemorated in more than 100 countries, initially in Europe and Canada. In Tanzania, the RD Day was first commemorated in 2016, and the most recent event was held on 29 th February 2020. The later was co-hosted by the Ali Kimara Rare Diseases Foundation (AKRDF) and Tanzania Society of Human Genetics (TSHG). The event was graced by the Hon. Dr. Hamisi Kigwangalla Minister of tourism and natural resources who represented the Vice President of the United Republic of Tanzania as the Guest of Honour. Also, in attendance were varioushigh-level Government officials, representatives of cooperates, academia, civil society, and individuals with RDs and their families. The organizers and other stakeholders utilized the event to advocate for policies and interventions to address the challenges facing individuals and children with RDs. This paper documents the highlights and presents the proposed call for actions of the 2020 RD day in Tanzania, with the overall goal of improved lives of patients and their families through increased access to adequate and high-quality health services and the development of appropriate policies.

Applied Microbiology and Biotechnology, 2020

The application of biocontrol biopesticides based on plant growth–promoting rhizobacteria (PGPR),... more The application of biocontrol biopesticides based on plant growth–promoting rhizobacteria (PGPR), particularly members of the genus Bacillus, is considered a promising perspective to make agricultural practices sustainable and ecologically safe. Recent advances in genome sequencing by third-generation sequencing technologies, e.g., Pacific Biosciences’ Single Molecule Real-Time (PacBio SMRT) platform, have allowed researchers to gain deeper insights into the molecular and genetic mechanisms of PGPR activities, and to compare whole genome sequences and global patterns of epigenetic modifications. In the current work, this approach was used to sequence and compare four Bacillus strains that exhibited various PGPR activities including the strain UCMB5140, which is used in the commercial biopesticide Phytosubtil. Whole genome comparison and phylogenomic inference assigned the strain UCMB5140 to the species Bacillus velezensis. Strong biocontrol activities of this strain were confirmed in several bioassays. Several factors that affect the evolution of active PGPR B. velezensis strains were identified: (1) horizontal acquisition of novel non-ribosomal peptide synthetases (NRPS) and adhesion genes; (2) rearrangements of functional modules of NRPS genes leading to strain specific combinations of their encoded products; (3) gain and loss of methyltransferases that can cause global alterations in DNA methylation patterns, which eventually may affect gene expression and regulate transcription. Notably, we identified a horizontally transferred NRPS operon encoding an uncharacterized polypeptide antibiotic in B. velezensis UCMB5140. Other horizontally acquired genes comprised a possible adhesin and a methyltransferase, which may explain the strain-specific methylation pattern of the chromosomal DNA of UCMB5140. • Whole genome sequence of the active PGPR Bacillus velezensis UCMB5140. • Identification of genetic determinants responsible for PGPR activities. • Role of methyltransferases and epigenetic mechanisms in evolution of bacteria.

Frontiers in Microbiology, 2019

A Baseline Evaluation of Bioinformatics Capacity in Tanzania Reveals Areas for Training, 2021

Due to the insufficient human and infrastructure capacity to use novel genomics and bioinformatic... more Due to the insufficient human and infrastructure capacity to use novel genomics and bioinformatics technologies, Sub-Saharan Africa countries have not entirely ripped the benefits of these technologies in health and other sectors. The main objective of this study was to map out the interest and capacity for conducting bioinformatics and related research in Tanzania. The survey collected demographic information like age group, experience, seniority level, gender, number of respondents per institution, number of publications, and willingness to join the community of practice. The survey also investigated the capacity of individuals and institutions about computing infrastructure, operating system use, statistical packages in use, the basic Microsoft packages experience, programming language experience, bioinformatics tools and resources usage, and type of analyses performed. Moreover, respondents were surveyed about the challenges they faced in implementing bioinformatics and their wi...

Effluent and effluent-contaminated soil samples collected from Mufindi Paper Mill Limited, Iringa... more Effluent and effluent-contaminated soil samples collected from Mufindi Paper Mill Limited, Iringa Tanzania were investigated for the presence of cellulolytic bacteria. The components of cellulase are endoglucanase, exoglucanase and β-glucosidase and these are very important for complete hydrolysis of cellulose to glucose monomers. Isolates were grown on nutrient agar and screened for cellulolytic activity on carboxymethylcellulose (CMC) agar plates using Gram’s iodine solution. Cellulases activities; endoglucanase, exoglucanase and β-glucosidase were assayed using CMC, avicel and cellobiose substrates, respectively by dinitrosalicyclic acid method. Out of 17 cellulolytic isolates obtained, crude enzyme extracts of only five isolates expressed all cellulases activities, the highest activity being on cellobiose followed by CMC and least on avicel. The maximum endoglucanase (0.0701 ± 0.010 U/ml), exoglucanase (0.0081 ± 0.001 U/ml) and βglucosidase (0.0738 ± 0.002 U/ml) activities from ...

Nature Human Behaviour

Changing scientific meetings for the better Conferences are a pivotal part of the scientific ente... more Changing scientific meetings for the better Conferences are a pivotal part of the scientific enterprise, but large in-person meetings have several disadvantages. As the pandemic experience has shown, online meetings are a viable alternative. Accelerating efforts to improve conferences in virtual formats can lead to a more equitable and sustainable conference culture.

bioRxiv (Cold Spring Harbor Laboratory), Feb 9, 2023

Orphanet Journal of Rare Diseases

Applied Microbiology and Biotechnology, 2020

Frontiers in Microbiology, 2019

A Baseline Evaluation of Bioinformatics Capacity in Tanzania Reveals Areas for Training, 2021

Due to the insufficient human and infrastructure capacity to use novel genomics and bioinformatic... more Due to the insufficient human and infrastructure capacity to use novel genomics and bioinformatics technologies, Sub-Saharan Africa countries have not entirely ripped the benefits of these technologies in health and other sectors. The main objective of this study was to map out the interest and capacity for conducting bioinformatics and related research in Tanzania. The survey collected demographic information like age group, experience, seniority level, gender, number of respondents per institution, number of publications, and willingness to join the community of practice. The survey also investigated the capacity of individuals and institutions about computing infrastructure, operating system use, statistical packages in use, the basic Microsoft packages experience, programming language experience, bioinformatics tools and resources usage, and type of analyses performed. Moreover, respondents were surveyed about the challenges they faced in implementing bioinformatics and their wi...

Nature Human Behaviour