Université Evangélique en Afrique
  • Bukavu, Democratic Republic of the Congo
Recent publications
The fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), is currently an important pest of maize crops worldwide not only because of its dispersal ability but also because of its polyphagous feeding behaviour. Lack of sufficient information on the management of the fall armyworm attacks remains a crucial problem for maize smallholder farmers in Africa. In this study, 420 farmers were surveyed in central and west Africa using individual interviews to assess farmers' knowledges and perceptions of the fall armyworm damages and the management practices used. Most farmers (99.4%) were shown to recognize the fall armyworm and 92.5% claimed to already have damages in their fields. The fall armyworm seems not to be a new pest as most farmers identified it in different countries from 2015 to 2019. Apart from maize as the preferred crop of S. frugiperda, several alternative host plants including Napier grass, sorghum, onion, and cabbage were identified by the farmers. Although cultural and mechanical control methods are used by several farmers, the synthetic pesticide market is still preferred by almost half of the farmers (44.28%) who still use them. To control fall armyworm, 96.4% in Burkina Faso, 85.3% in Gabon, 65.2% in Benin and 25% in DR Congo reported using insecticides, against 5.9% in Senegal. Semiochemical-based method and biological control by promoting natural enemies of the fall armyworm are new concepts for farmers in DR Congo, Gabon and Benin. To avoid additional problems regarding health and resilience of agricultural systems, alternative methods such as push–pull approach, the development of biopesticides and resistant cultivars should form the basis of training given to farmers and should be popularized for sustainable control of the fall armyworm in central and west Africa.
Haphazard and opportunistic species occurrence (PO) data are widely used in species distribution models (SDMs) instead of high-quality species data gathered using appropriate and structured sampling methods, which is expensive and often spatially limited. Despite their widespread use in ecology, PO data are prone to errors and uncertainties, such as imperfect detectability, positional imprecision, and spatial niche truncation, which make their use analytically challenging for effective and adaptive biodiversity management and conservation. Using simulated data, this study investigates the effects of these uncertainties on the performance of spatial point process based presence-only and integrated SDMs. We investigated three SDMs in this study, one that ignores imperfect detectability: the presence-only model (PO model), and two that account for it: the thinned presence-only model (THINPO model) and the integrated model (PBPC model). The ability of these SDMs to produce accurate maximum likelihood estimates of intensity model coefficients and reliable predictions of species distributions under different data quality scenarios was investigated. The results show that SDMs that account for imperfect detectability (THINPO or PBPC models) are not applicable in situations of high detectability. In this situation, the PO model produces the most accurate maximum likelihood estimates of the models’ coefficients (β^k\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\hat{\beta }}_k$$\end{document}), and consequently the most accurate predictions of species distributions (λ^(s)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\hat{\lambda }}(s)$$\end{document}). The effects of positional uncertainty and spatial niche truncation on this SDM output are minimal. However, in situations of low detectability, it is preferable to use the PBPC model. Positional uncertainty and spatial niche truncation have negligible effects on the output of this SDM, except when positionally uncertain PO data are analyzed along with truncated PC data. These minimal effects of spatial niche truncation on SDM outputs demonstrate the transferability of SDMs. However, the effects of all these uncertainties may depend on the characteristics of the species. Prior to modeling species distributions, a multivariate environmental similarity surface analysis should be performed to test the similarity between data from the restricted region to be used for model calibration and data from the entire range. If this analysis reveals dissimilarities, larger spatial and ecological scales should be considered to address the issue of spatial niche truncation. Further efforts could address the effects of species characteristics on SDMs performance and assess the effects of species-specific uncertainties.
Retinoblastoma (RB) is a genetically predetermined intraocular malignant tumor, common in childhood, initiated by a mutation in the retnoblastoma gene (RB1), located on the long arm of chromosome13 (13q14). The lack of information on the genetics of RB in Bukavu motivated this study, with the aim of presenting the spectrum of mutations. Materials and methods This is an analytical cross-sectional study of 10 individuals, including 5 RB carrier children and 5 parents. Their deoxyrubonucleic acid (DNA) was extracted and 11 exons within the RB1 gene were amplified by Polymerase chain reaction, sequenced and analyzed by various bioinformatics tools. Result All the children had unilateral RB, diagnosed mostly at an age ≥2 years, male gender predominated, history of RB was absent in all subjects. A total of 11 of the 27 most frequently mutated exons that make up RB1 had been analyzed. The types of deleterious mutations found in exons 8 and 20 alone, in the 5 children and one parent, were of the following types: missense (26.6% vs. 16.7%), deletion (11.1% vs. 50%) and insertion (66.7% vs. 33.3%), generally associated with a frameshift and a splice site change. Disruption of protein synthesis was observed in all the children and in only one parent. Conclusion The deleterious genetic mutations identified by the study were known. The study suggested additional studies, integrating environmental factors that are currently believed to be involved in the occurrence of RB.
Background: Conflict-related sexual violence (CRSV) with the intent of forced pregnancy is common in conflict, and used as a way to dominate women and their society/community. There is growing recognition of the needs of children born of CRSV, particularly by humanitarian practitioners who are coming into contact with them in emergency settings. We sought to find out what is the state-of-the-art on interventions to support children born of CRSV (and their families)? Methods: We systematically searched electronic databases (JSTOR, Google Scholar, Scopus, Cairn Info and Embase) and hand searched reference lists of key publications, as well as non-governmental organisations (NGO), United Nations (UN) agencies, international organisations and governmental reports on this topic and in the area of genderbased violence (GBV), child protection, health and other sectors addressed at humanitarian practitioners. Results: Experiences of children born of CRSV include psychological, economic, medical, and legal aspects. Responses to their needs include food aid, medical care, housing assistance, financial support for the mothers of children born of CRSV, and therapeutic games and counselling. However, these responses remain insignificant and partial, and are very often only implemented in one setting. The paucity of the evidence base is clear. Conclusion: Children born of conflict related sexual violence are a special population, both because of the context in which they were conceived, and because of the experiences they face. To deal with the complexity of their situation and thus respond effectively to their holistic needs, various actors must work in synergy.
Pesticides like Mancozeb are being increasingly indispensable in the control of crop pests. Unfortunately, they have been implicated in genotoxicity due to their ubiquity, toxicological properties, persistence and presence in the food chain. This study sought to evaluate the efficacy of powdered avocado seed on reproductive parameters in the management of oxidative stress in female rabbits caused by the herbicide Mancozeb. Twenty-eight female rabbits aged 7–8 months and weighing between 2780.4 g and 3143.7 g were randomly divided into four groups of seven rabbits each. Each group received for 90 consecutive days distilled water or Mancozeb associated or not with avocado seed powder orally as follows: T1: 10 ml distilled water; T2, T3 and T4: 100 mg/kg bw Mancozeb. This was followed by oral administration of 250, 500, and 0 mg/kg of avocado seed powder for T2, T3, and T4, respectively. Water and feed were distributed ad libitum. Collected data concerned growth, carcass and reproductive performances, hematological and biochemistry characteristics. Results demonstrated that pregnant and lactating female rabbits administered Mancozeb exhibited a significant decrease (P
Soil nutrient depletion and poor farming practices are serious challenges limiting crop productivity in soils of the eastern Democratic Republic of Congo (D.R. Congo). An experiment was conducted in two cropping seasons to assess the effect of plant density (25 plants/m2 and 33 plants/m2) and fertilizer application (with and without NPK) on the yield and yield components of three biofortified common bean varieties (HM21-7, RWR2245 and RWR2154). The experiment involved two plant densities, two fertilizer rates and three varieties arranged in a split-split plot design with three replications. Results showed that yield significantly varied with plant density, variety and fertilizer rate (p < 0.05). The best performing variety in terms of grain yield was HM21-7 (1.5 t ha−1) as compared to RWR2154 (1.09 t ha− 1) and RWR2245 (1.14 t ha− 1). The NPK fertilizer increased the grain yield by 38.2%. Grain yield increased also with the plant density, highest grain yield being recorded on higher plant density (1.37 t ha− 1) as compared to low lower plant density (1.25 t ha− 1). Agronomic efficiency (AE) was influenced by the variety, with the highest AE obtained on RWR2245 (23.27 kg kg− 1) and on high plant density (20.34 kg kg− 1). Therefore, we concluded that increasing the plant density by reducing the plant spacing, using NPK fertilizer and high yielding varieties provide with an opportunity to improving common bean yields on Nitisols dominating the highlands of eastern D.R. Congo.
Background: Panzi General Reference Hospital (HGR Panzi) in the Democratic Republic of Congo follows a large number of patients living with HIV-1 (PLWHIV). Although antiretrovirals (ARVs) are available, HIV-1 viral load (HIV-VL) measurement has only been implemented in the hospital since 2018. No data on ARV resistance levels and ARV dosage in plasma have yet been published for this region. We determined the prevalence of virological failure due to ARV resistance amongst patients and assessed the degree of genotypic resistance of the viral strains. Methods: We performed an HIV-VL test and determined dosage of ARVs on samples collected from 205 PLWHIV at HGR Panzi between 2017 and 2018, including 13 ARV-naive patients. Genotypic resistance testing was performed on all samples with detectable HIV-VLs, and interpreted with the Agence Nationale de Recherches sur le Sida (ANRS) 2018 algorithm. Results: Baseline resistance to NNRTIs was found in 2 of the 13 treatment-naive individuals (15%). ARV dosage was non-optimal for 44/192 of treated patients (22.9%), with an HIV-VL ≥1000 IU/mL for 40/192 (20.8%) of them. In particular, treatment-experienced viruses presented resistance to at least one NRTI (52.5%), to at least one NNRTIs (70%) or to at least one PIs (15%). Finally, two samples contained viruses with resistance polymorphism in the integrase gene. Conclusions: The high level of resistance to ARVs observed during this study, mainly due to treatment compliance default, fully justifies the implementation of means for closer patient monitoring. The provision of VL tests and therapeutic education management tools in a PLWHIV follow-up remains an absolute necessity to best adapt the current treatment lines in this region.
Background The fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), poses a threat to the food security of populations in sub-Saharan Africa because of its damage to maize crops. As alternative to the use of hazardous pesticides, microbial control is one of the most promising sustainable approaches adopted to limit the damages caused by S. frugiperda. The sampling targeted mainly larvae of S. frugiperda; however, during the survey, cadavers of earwig found on the same sampling sites were also collected and involved in the study. Cadavers of targeted insects, with and without sign of fungal infection, were sampled from 3 localities in eastern DR Congo. Culture of fungal isolates was performed in selective Sabouraud dextrose agar media. Results Morphological study of fungal features such as conidia (shape and size) and conidiophores showed that the isolates were from the genus Beauveria. Conidial measurements were highly variable and ranged from 2.4 to 3.6 μm in length and from 1.75 to 3.0 μm in width. Molecular characterization and phylogenetic analysis of the 2 Beauveria isolates based on DNA sequencing of ITS-5.8S region confirmed that both isolates belong to Beauveria bassiana. The 2 isolates of B. bassiana P5E (OP419735.1) and KA14 (OP419734.1) were isolated from cadavers of FAW and earwig, respectively. The alignment with different sequences of B. bassiana from different continent showed that P5E belonged to the same clade of previous isolates reported from Iran and Mexico, while KA14 was with the same clade as isolates from Kenya and China. Conclusion To our knowledge, this is the first study reporting the occurrence of B. bassiana infecting FAW and earwig in eastern DR Congo and in Africa. Keywords Spodoptera frugiperda, Beauveria bassiana, Epizooty, Earwig, Molecular characterization
Introduction: Breast Cancer Associated with Pregnancy( "BCAP" ) is one of the rare entities of breast tumor pathologies in senology. According to the literature, it has a low frequency. But it is characterized by a clinical picture often very severe. The objective of this article is to illustrate the particularities of this type of cancer by the clinical cases diagnosed in 2022. In addition, to discuss and analyze the epidemio-clinical, histological, therapeutic aspects and short-term prognosis; consented genetic testing was initiated and justified by young age (less than 32 years). Patients and methods: This is a 12-month cross-sectional study, for analytical purposes with prospective collection, conducted at the Department of Gynaecology and Anatomopathology of Panzi/UEA Hospital in 2022. Two patients collected, after clinical examination, met the criteria for selecting BCAP definitions according to the "Journal of Gynaecological-Obstetrics" (36) [6]. Then, their biopsy and blood samples allowed histo-genetic diagnosis at the anatomopathology and molecular biology laboratories of the UEA with counter-expertise in Netherland-Amsterdam. Results: Over a period of twelve months and in a sample of 28 patients with breast cancer, there were 2 cases of BCAP, or 7% incidence. The patients were Bukavu residents from South Kivu, married, under 32 years of age and all with higher education. They consulted late; more than a year, after discovery of breast nodules by self-palpation. All have re-acknowledged having undergone exposure to potential ionizing irradiation. Risk factors were analyzed. For patient (A): menarche at 17 years, ages of marriage and 1st pregnancy at 31 years, primiparity, no breastfeeding, history of breast tumors and local treatment with indigenous products. For (B), obesity, shortened breastfeeding and taking hormonal con-traceptions were noted. The clinic noted in common, advanced cancer, large adherent mass; but, for the patient (A) were associated cachexia, infectious syndrome, anemia and fetal distress ended by fetal death in utero. Anatomical pathology has found a common type "advanced invasive ductal carcinoma"; grade SBR III for (A) and SBR I for (B). The extension assessment noted more peculiarities for (A) with hyperleukocytosis, low hemoglobin, radiopulmonary images in favor of metastases. Genetic testing, looking for BRCA 1&2 mutations, suspected the BRCA1 mutation for both patients, after PCR by presence of amplification of primers 185 and 187 at the UEA/HGRPanzi laboratory. However, sequencing done at the MACROGEN - Netherland laboratory, confirmed the presence of mutations at exon 2 of the objectified BRCA1 gene in the patient (B). Due to lack of resources, genetic analysis of other exons of the BRCA1 and BRCA2 genes has not been performed to exclude associated muta-tions. Conclusion: BCAP, being classically rare, had a very high frequency (7%) in our series. It has affected patients of young age (less than 32 years), diagnosed with late-stage invasive ductal carcinoma with at least 50 percent genetic factor positivity (BRCA 1 mutation). These elements suggest the prospect of undertaking a large-scale study to investigate the most common breast cancer risk factors in Bukavu.
Background CAR is one of the poorest countries in the world. While UN statistics suggest that there is no health emergency in the country, two recently published mortality surveys contradict this. Moreover, recent accusations of massive scale human rights abuses by mercenaries suggested the need for a nationwide mortality survey. Methods Two stage cluster surveys were conducted in two different strata: one in the roughly half of the country within the Government’s control, and one in the areas mostly outside of the Government’s control. We randomly selected 40 clusters of 10 households in each stratum. The survey included questions on vital events with open-ended questions about health and household challenges at the beginning and end of each interview. Results 70 of 80 selected clusters were successfully visited. We interviewed 699 households, containing 5070 people. 11 households (1.6%) refused to be interviewed and approximately 18.3% of households were absent at the time of visitation, mainly in the safer Government controlled areas. Interviewed households had a birth rate of 42.6 /1000 / year (95%CI 35.4–59.7) and a crude mortality rate (CMR) of 1.57 /10,000/day (95%CI: 1.36–1.78). The birth rate was lower and the death rate markedly higher in the strata outside of Government control. Families described malaria or fever, and diarrhea as the primary reported causes of death with violence accounting for 6% of all deaths. Conclusions CAR is experiencing a severe health emergency, with the highest measured nationwide mortality in the world to our knowledge. UN published death rate estimates appear to be less than one fourth of reality. There is a desperate need for food aid in the form of general distributions in CAR, along with the accompanying work programs, seed and tool distributions needed to restart local economies. This is of particular importance in rural areas outside of the Government control. While some humanitarian actors are doing their best to respond, the crisis level mortality rate suggests that the needs in CAR are being largely unmet.
Processing potato tubers into flour can be done using various methods, which can impact the flour’s nutritional and pasting properties. This study evaluated the effects of five different processing methods, namely, low-temperature blanching, followed by oven drying (LTB_OD), high-temperature blanching followed by oven drying (HTB_OD), boiling followed by oven drying (Boiling_OD), freeze drying (FD), and oven drying (OD), on the nutritional and pasting properties of potato flour derived from Shangi potato variety. The relationships between the nutritional and pasting properties were determined using Pearson’s correlation and principal component analyses (PCA). The results indicated that freeze-dried flour exhibited higher protein content (10.17%), sucrose (88.87 mg/100 g), and magnesium (44.90 mg/100 g) content, while Boiling_OD flour showed the lowest protein (6.41%), sucrose (15.34 mg/100 g), and magnesium (35.55 mg/100 g) content. All potato flour types demonstrated a decrease in apparent viscosity with increasing shear rate, with freeze-dried flour having the highest apparent viscosity. Freeze-dried flour showed the highest peak viscosity (7098.33 cP) and breakdown viscosity (2672.00 cP). The highest final viscosity (7989.00 cP) was recorded in HTB_OD flour. Protein (r = −0:92), fiber (r = −0:81), and fat (r = −0:83) negatively correlated with the peak viscosity, while sugars (glucose (r = 0:95), fructose (r = 0:93), and sucrose (r = 0:87)) and phosphorus (r = 0:86) positively correlated with pasting properties. The first two principal components explained 90.2% of the total variance. Oven drying and freeze drying were in close proximity in the PCA score plot, indicating that these two flour types have similar chemical and pasting properties. In conclusion, the different processing methods altered the chemical and pasting properties of the flour, therefore influencing their potential use in the food industry. Considering the correlations established in this study, it is likely that chemical properties could be used to predict the pasting properties of potato flour.
Dairying is one of the new promising economic sectors in eastern Democratic Republic of Congo (DRC), but still not explored enough to ensure consumers’ safety. This study aimed to assess the health risks and nutritional profile of milk products along the value chain in South-Kivu and Tanganyika provinces. A total of 288 milk actors, including 160 producers, 35 collectors and 93 vendors, were concerned for interview and milk samples collection. A total of 302 milk samples (159 raw, 44 pasteurized, 76 fermented and 19 white cheese so-called “Mashanza”) were collected for physicochemical [pH, fat, non-fat dry matter (NFDM), lactose, protein, freezing point, density] and microbiological (total Aerobic Mesophilic Flora, Escherichia coli, Total Coliforms, Fecal Coliforms, Salmonella and Staphylococci) analyses. Results revealed that the physicochemical characteristics of the milk mostly varied according to the type of milk and the regions. The pasteurized milk from Tanganyika presented the best physicochemical parameters [crude protein (CP) = 4.36%, Fat = 4.06%, NFDM = 12%, lactose = 5.4%, density = 1.02 and pH = 6.59] compared to other types of milk. For microbiology, no E. coli was recorded but Salmonella and Staphylococci were found in all the milk types with the values not exceeding 3×104 CFU ml−1 and 3×103 CFU ml−1, respectively. This implies a long-term consumers’ health issue if appropriate measures are not taken by milk actors along the value chain. The microbiological quality was influenced by the ecologies of production axis (representing the production zones) and by handling methods and infrastructures used by the actors involved along the value chain. Factors related to animal husbandry, milking method, milk processing and packaging had no significant effect on the physicochemical parameters under study. These results indicated that health risks for milk consumers are accrued by production practices and handling by milk actors due to shortage of required skills and appropriate equipment along the milk value chain. Observance of hazard analysis critical control point (HACCP) measures is carefully required along the milk value chain nodes to improve the quality of milk produced and sold and thus reduce the risks among consumers in South-Kivu and Tanganyika provinces.
Mental Health and Psychosocial Support are integral components of the multisectoral programs addressing wartime sexual violence. In the Democratic Republic of Congo, an integrated framework known as the one-stop centre model was implemented at Panzi Hospital for delivering medical, legal, psychosocial, and socioeconomic support services for wartime sexual violence survivors. While recent developments broadly described this model with more focus on its medical pillar, there is limited knowledge on how its psychosocial support component can be harnessed in addressing wartime sexual violence. This article explored the roles and ethics of psychosocial support in integrated health services based on the research data from 11 in-depth interviews with the psychosocial support workers and desk reviews. Findings The findings of this study indicated that the roles and ethics of psychosocial workers in addressing wartime sexual violence are limited by the lack of adequately trained staff members, low professional status, and complex ethical challenges. In this case, psychosocial support draws more from virtue ethics and moral constructivism and less from professional utilitarianism and deontology. While both approaches are integral to providing support services, combining them is necessary for the complementarity and consistency of therapeutic processes. The study's findings also demonstrated the lack of professional social work and mental health interventions in the Congo and suggested coordinated actions engaging social work education, policy, and research developments. Applications We conclude that the roles and ethics of psychosocial support should be of serious concern to decision-makers, practitioners, and educators.
Objective: Trial of labor after two Cesarean sections (TOLA2C) is feasible in medium-and- high-resource countries with good maternal-infant prognosis reported. This study aims to determine the success rate of TOLA2C in the low-resource setting of Democratic Republic of Congo (DRC) and to describe factors associated with success and related complications. Methods: A prospective cohort study was conducted from 2015-2020 in a teaching hospital. Patients who underwent TOLA2C were followed across prenatal visits, onset of spontaneous labor, and delivery. Demographics and clinical characteristics were documented. Pearson's and Fisher's chi-square tests were used. Predictors of successful vaginal delivery were determined by logistic regression(p˂0.05). Results: Among 532 patients, the success rate of TOLA2C was 405(76.1%). Factors associated with success included birth spacing ≥ 24 months(OR=2.27;95%CI:1.43-3.60), previous vaginal delivery(OR=11.34;95%CI:7.11-18.09), intercalated vaginal delivery(OR=17.37;95%CI:8.83-34.13), previous Cesareans during labor(OR=3.22;95%CI:1.50-6.87), cervical dilation >6cm(OR=4.13;95%CI:2.01-8.44) and/or complete dilation on arrival in the delivery room (OR=7.61;95%CI:1.82-31.88), and oxytocin stimulation(OR=3.71:1.74-7.92). No association with hemorrhage, uterine rupture, transfer to neonatology, or maternal-neonatal deaths were observed. Conclusions: TOLA2C is possible in a low-resource setting with a high success rate and low rates of complications. Patient selection and obstetrical team competency are needed.
Une enquête a été réalisée sur l’île d’Idjwi, à l’est de la République démocratique du Congo, pour évaluer les pratiques phytosanitaires actuelles et les risques perçus par les agriculteurs. Les maraîchers, constitués en majorité de femmes (68 %) utilisent en cultures de tomate, de choux et d’aubergine, une diversité de fongicides, souvent en combinaison (43 %) avec des insecticides tels que la cyperméthrine. Le choix de ces pesticides est principalement déterminé par la perception de leur efficacité par les maraîchers et leur disponibilité sur les marchés locaux, où les revendeurs sont la principale source d’information des agriculteurs. L’incapacité des autorités compétentes (Office national de la protection des végétaux, Office congolais de contrôle) à limiter la distribution des pesticides non autorisés et très dangereux ( e.g. , profénofos), l’analphabétisme (39 % des agriculteurs) et l’absence de formation à l’usage des pesticides ne favorisent pas de bonnes pratiques phytosanitaires. De plus, le non port des équipements de protection (62 % des cas) et le non-respect des délais de sécurité ainsi que la négligence des pratiques d’hygiène après traitement (50 % de cas) exposent les maraîchers aux risques des pesticides, avec un impact potentiel direct sur leur santé. Enfin, les déchets de pesticides abandonnés sur les exploitations (60 %) et la mauvaise gestion de la bouillie restante après traitement contribuent à polluer l’environnement. Nous proposons donc une série d’actions pour favoriser une gestion rationnelle des pesticides et une amélioration des pratiques phytosanitaires des agriculteurs de l’île d’Idjwi.
Background Located in the Eastern Democratic Republic of Congo (South-Kivu), Kalehe and Idjwi are two relatively unexplored territories with little to no research on edible insects even though anthropo-entomophagy practice is widespread. This study therefore aimed at exploring the biodiversity, perception, consumption, availability, host plants, harvesting techniques, and processing techniques of edible insects. Methods Data were collected through a field survey using three techniques, namely structured interviews, direct observations, and insect collection and taxonomy. A total of 260 respondents, 130 in each territory, were interviewed. The field survey focused on inventorying commonly edible insects as well as recording consumer preferences, preference factors, seasonal availability, host plants, harvesting techniques, and processing and preservation methods. Samples for taxonomic characterization were preserved in 70% alcohol. Results Nine edible insects, namely Ruspolia differens Serville 1838, Gryllotalpa Africana Palisot de Beauvois 1805, Locusta migratoria Linnaeus 1758, Macrotermes subhyalinus Rambur 1842, Gnathocera trivittata Swederus 1787, Rhynchophorus phoenicis Fabricius 1801, Vespula spp. Linnaeus 1758, Apis mellifera Linnaeus 1758, and Imbrasia oyemensis Rougeot 1955, were recorded as being consumed either as larvae, pupae, and adults. Ruspolia differens and M. subhyalinus were reported as the most preferred by consumers in the studied territories. A scatter plot of matrices and Pearson's correlations showed a negative correlation between preference based on taste, size, and shape, as well as perceived nutritional value. Their seasonal availability differs from one species to another and correlated with host plants availability. Harvesting techniques and processing and preservation methods depend on species, local knowledge, and practices. Conclusion The huge edible insect diversity observed in Kalehe and Idjwi is evidence of anthropo-entomophagy practices in the area. In addition to being an important delicacy and traditional foods, edible insects can contribute to food, environmental, and financial security through local business opportunities. Households can rely on edible insects to meet their nutritional needs instead of conventional livestock. Indigenous practices and technologies used for harvesting, processing, and preserving edible insects must be improved to meet international standards to increase the market and capitalize on the economic potential of edible insects.
This experiment was conducted to investigate the effect of dried Leucaena ( Leucaena leucocephala ) and cassava ( Manihot esculenta ) leaves on feed intake, milk production, and milk composition of Holstein Friesian x Ankole crossbred cows. Three cows in early lactation, with initial milk production of 4 ± 1.20 kg/day and 359 ± 24 kg average live body weight, were randomly assigned to the experimental diet in a 3x3 Latin square design. Three 15-day experimental periods were adopted (1 to 10-day: diet adaptation and 11 to 15-day: data collection). Cows were fed on a freshly chopped Guatemala grass diet supplemented with 1.25 kg DM of brewers’ spent grain (control). The experimental diets were similar to the control diet differing in the presence of dried Leucaena or cassava leaves, both at the inclusion rate of 20% of the basal diet intake. Total dry matter intake, nutrient intake, milk production, and milk composition showed significant variation among treatments. Cows supplemented with dried cassava leaves had higher total dry matter intake and organic matter intake. Leucaena significantly increased (p < 0.001) daily milk production by 15% compared to cassava (3%). Leucaena had a higher milk fat content (38.44 g), while cassava and the control diet had higher milk protein (38.53 and 38.43 g), lactose (56.79 g and 56.111 g), and not-fat solids (102.41 g and 101.27 g). These results indicate that dried Leucaena and cassava leaves can be used as protein supplements for Guatemala grass basal diet for crossbred cows to improve milk production and quality.
Agrius convolvuli (Lepidoptera: Sphingidae) is a pest that feeds on young sweet potato leaves causing severe plant defolia-tion. This study was designed to report for the first time on the occurrence of the pest in the Haut-Katanga province in DR Congo. Survey and observations were conducted during the growing season in ten cities of the Haut Katanga province to detect the presence of A. convolvuli. Fifty-two sweet potato fields were inspected during the season. Larvae and pupae were collected in each city and reared in the laboratory at the University of Lubumbashi, DR Congo. Results revealed that the pest occurs in the province with Lubumbashi and Kasumbalesa being the most highly infested with 18.80±11.36 and 18.71±8.13% of infestation, respectively. The highest number of larvae per field and per plant was recorded in Lubumbashi alone with 18.80±8.04 and 3.80±1.48, respectively. Classification of sweet potato leaf damage indicated that Kasumbalesa, Sakania and Lubumbashi had high levels of damage. Positive relationships were observed between infestation rate and number of larvae per field (R 2 =0.3069; t=4.705; p<0.0001) but also between infestation rate and number of larvae per plant (R 2 =0.4478; t=6.368; p<0.0001). The findings of the current study suggest that A. convolvuli could be a potential threat to sweet potato production in the Haut-Katanga province.
Machine learning algorithms, especially random forests (RFs), have become an integrated part of the modern scientific methodology and represent an efficient alternative to conventional parametric algorithms. This study aimed to assess the influence of data features and overdispersion on RF regression performance. We assessed the effect of types of predictors (100, 75, 50, and 20% continuous, and 100% categorical), the number of predictors (p = 816 and 24), and the sample size (N = 50, 250, and 1250) on RF parameter settings. We also compared RF performance to that of classical generalized linear models (Poisson, negative binomial, and zero-inflated Poisson) and the linear model applied to log-transformed data. Two real datasets were analysed to demonstrate the usefulness of RF for overdispersed data modelling. Goodness-of-fit statistics such as root mean square error (RMSE) and biases were used to determine RF accuracy and validity. Results revealed that the number of variables to be randomly selected for each split, the proportion of samples to train the model, the minimal number of samples within each terminal node, and RF regression performance are not influenced by the sample size, number, and type of predictors. However, the ratio of observations to the number of predictors affects the stability of the best RF parameters. RF performs well for all types of covariates and different levels of dispersion. The magnitude of dispersion does not significantly influence RF predictive validity. In contrast, its predictive accuracy is significantly influenced by the magnitude of dispersion in the response variable, conditional on the explanatory variables. RF has performed almost as well as the models of the classical Poisson family in the presence of overdispersion. Given RF’s advantages, it is an appropriate statistical alternative for counting data.
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116 members
Gaston Amzati
  • Faculty of Agriculture
Karume Katcho
  • Agriculture and Environment
Rodrigue B. B. Ayagirwe
  • Department of Animal Production
Gustave Nachigera Mushagalusa
  • Faculty of Agriculture
Jean Mondo Mubalama
  • Crop Production
Bukavu, Democratic Republic of the Congo