111 research outputs found

    Hydraulic Relationships of the Ikpoba River for Flood Studies

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    Flooding is a temporary condition of partial or complete inundation of normally dry areas of overflow of inland or tidal waters or from extreme and rapid accumulation of runoff. Flooding phenomenon is considered the world worst global hazard in terms of magnitude, occurrence and geographical spread, loss of life and property, displacement of people and socio-economic activities. In the tropical and sub-tropical regions, severe flooding hazards resulting from heavy thunderstorms, torrential downpours, hurricanes and tidal waves are yearly occurrences. Flood disasters are said to account for one-third of all natural catastrophes throughout the world by number and economic losses and are responsible for more than half of the facility damage (Askew, 1999). In Nigeria, many urban floods occur because of excessive extreme rainfalls improper land use and poor drainages. It has been estimated that more than seven hundred thousand hectares of useful land for agricultural and residential purposes are either lost or rendered useless due to annual floods (David and Aggrawal 2008). The Niger Delta region of Nigeria is mostly flat low lying swampy basin resulting in severe regular flooding which has led to a limited land area for residence. Benin City experiences flash Flood and Flood pondages. Areas are inundated for more than two hours during flood episodes with an average water height of one meter (Ogbonna, et al 2011). As a result of flood events, every year government spends huge sums of money on compensation for flood victims, yet, the problems are unabated. Decision makers need supporting tools such as knowledge of extreme flood magnitudes and probability of re-occurrence, flood stages and river discharge relationships to enable decisions on a particular line of action which would be most adequate in mitigating against flood This study seeks to derive hydraulic relationships for the Ikpoba River which can serve as decision support tools that can be used in evaluating flood damages in suburban-areas of  Benin-city metropolis. The specific objectives are to: i. Determine the exceedance frequency discharge relationship for the Ikpoba River.ii. Establish depths for longitudinal and cross sectional profiles of the Ikpoba Riveriii. Derive the stage discharge relationship of the Ikpoba River

    Lassa fever awareness and knowledge among community residents in Ondo State, Nigeria

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    Background: The Lassa fever outbreak in Ondo State in 2018 recorded high morbidity and mortality. This study was conducted to assess awareness and knowledge of Lassa fever preventive measures among community residents in the affected areas in order to guide risk communication interventions.Methods: A community-based descriptive cross-sectional study was conducted in six affected Local Government Area (LGAs), involving heads of households selected using a multistage sampling technique. A structured pre-tested questionnaire was administered to 2992 consenting study participants and data was analysed using IBM Statistical Package for Social Sciences version 20.0.Results: Over three quarters 2, 537 (84.8%) of respondents were aware of Lassa fever of which 2, 363 (93.1%) knew that multimammate rat transmits the disease to humans. Also, 1804 (71.1%) knew that washing hands regularly could prevent the disease. However, only 845 (33.3%) of the respondents who reported awareness of the disease knew that cooking all foods properly before eating could prevent the disease. The predictors of good knowledge of Lassa fever were being a female (p= 0.017), having secondary or tertiary education (p=0.001), and currently married or divorced (p=0.01).Conclusion: A high level of awareness, but inadequate knowledge of some preventive measures of Lassa fever were observed among community members. Risk communication messages should focus more on preventive measures of the disease targeting young males with low education in these LGAs, the epicentres of the outbreak.Keywords: Awareness; Knowledge; Lassa fever; Risk communication; Ondo Stat

    Maximizing the incorporation of cassava flour as an adjunct in bread baking in Nigeria

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    Bread is popular around the world and is one of the world’s oldest foods. Bread is usually made from common wheat-flour dough. Till date most people are not familiar with other types of bread apart from that made from 100% wheat flour. When a part of wheat flour is replaced with flours from other food sources (yam, cassava, etc) the wheat gluten is automatically reduced. This study aimed at re-examining the approval of ten percent (10%) cassava flour inclusion in bread baking in Nigeria and evaluating higher % substitutions, with a view to increasing cassava carrying capacity for producing acceptable bread. The water absorption capacity (WAC) of wheat, cassava and composite flours ranged from 62.7 to 79% while oil absorption capacity (OAC) ranged from 4.5 to 72%. As cassava percent inclusion increased both WAC and OAC increased. Bread loaves produced from 10-20% inclusions without egg white had sensory scores of 3.2 to 3.9 and were significantly (p < 0.05) better than 25-30% wheat cassava composite bread loaves. In all sensory attributes, 10-20% cassava inclusion, with added egg white, produced bread loaves which were as good as 100% wheat bread. In terms of taste, colour, odour and texture 25-30% composite bread loaves had identical sensory values. This study showed that bread of acceptable quality can be produced from wheat flour substituted with up to 30% cassava flour

    Potentials of 3D extrusion‐based printing in resolving food processing challenges: A perspective review

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    Three-dimensional (3D) printing has promising application potentials in improving food product manufacturing, increasingly helping in simplifying the supply chain, as well as expanding the utilization of food materials. To further understand the current situation of 3D food printing in providing food engineering solutions with customized design, the authors checked recently conducted reviews and considered the extrusion-based type to deserve additional literature synthesis. In this perspective review, therefore, we scoped the potentials of 3D extrusion-based printing in resolving food processing challenges. The evolving trends of 3D food printing technologies, fundamentals of extrusion processes, food printer, and printing enhancement, (extrusion) food systems, algorithm development, and associated food rheological properties were discussed. The (extrusion) mechanism in 3D food printing involving some essentials for material flow and configuration, its uniqueness, suitability, and printability to food materials, (food material) types in the extrusion-based (3D food printing), together with essential food properties and their dynamics were also discussed. Additionally, some bottlenecks/concerns still applicable to extrusion-based 3D food printing were brainstormed. Developing enhanced calibrating techniques for 3D printing materials, and designing better methods of integrating data will help improve the algorithmic representations of printed foods. Rheological complexities associated with the extrusion-based 3D food printing require both industry and researchers to work together so as to tackle the (rheological) shifts that make (food) materials unsuitable.info:eu-repo/semantics/publishedVersio

    Mapping suitable great ape habitat in and around the Lobéké National Park, South-East Cameroon

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    Abstract As a result of extensive data collection efforts over the last 20?30 years, there is quite a good understanding of the large-scale geographic distribution and range limits of African great apes. However, as human activities increasingly fragment great ape spatial distribution, a better understanding of what constitutes suitable great ape habitat is needed to inform conservation and resource extraction management. Chimpanzees (Pan troglodytes troglodytes) and gorillas (Gorilla gorilla gorilla) inhabit the Lobéké National Park and its surrounding forest management units (FMUs) in South-East Cameroon. Both park and neighboring forestry concessions require reliable evidence on key factors driving great ape distribution for their management plans, yet this information is largely missing and incomplete. This study aimed at mapping great ape habitat suitability in the area and at identifying the most influential predictors among three predictor categories, including landscape predictors (dense forest, swampy forest, distance to water bodies, and topography), human disturbance predictors (hunting, deforestation, distance to roads, and population density), and bioclimatic predictor (annual precipitation). We found that about 63% of highly to moderately suitable chimpanzee habitat occurred within the Lobéké National Park, while only 8.4% of similar habitat conditions occurred within FMUs. For gorillas, highly and moderately suitable habitats occurred within the Lobéké National Park and its surrounding FMUs (82.6% and 65.5%, respectively). Key determinants of suitable chimpanzee habitat were hunting pressure and dense forest, with species occurrence probability optimal at relatively lower hunting rates and at relatively high-dense forest areas. Key determinants of suitable gorilla habitat were hunting pressure, dense forests, swampy forests, and slope, with species occurrence probability optimal at relatively high-dense and swampy forest areas and at areas with mild slopes. Our findings show differential response of the two ape species to forestry activities in the study area, thus aligning with previous studies

    Development of reference transcriptomes for the major field insect pests of cowpea: a toolbox for insect pest management approaches in West Africa

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    Cowpea is a widely cultivated and major nutritional source of protein for many people that live in West Africa. Annual yields and longevity of grain storage is greatly reduced by feeding damage caused by a complex of insect pests that include the pod sucking bugs, Anoplocnemis curvipes Fabricius (Hemiptera: Coreidae) and Clavigralla tomentosicollis StÄl (Hemiptera: Coreidae); as well as phloem-feeding cowpea aphids, Aphis craccivora Koch (Hemiptera: Aphididae) and flower thrips, Megalurothrips sjostedti Trybom (Thysanoptera: Thripidae). Efforts to control these pests remain a challenge and there is a need to understand the structure and movement of these pest populations in order to facilitate the development of integrated pest management strategies (IPM). Molecular tools have the potential to help facilitate a better understanding of pest populations. Towards this goal, we used 454 pyrosequencing technology to generate 319,126, 176,262, 320,722 and 227,882 raw reads from A. curvipes, A. craccivora, C. tomentosicollis and M. sjostedti, respectively. The reads were de novo assembled into 11,687, 7,647,10,652 and 7,348 transcripts for A. curvipes, A. craccivora, C. tomentosicollis and M. sjostedti, respectively.Functional annotation of the resulting transcripts identified genes putatively involved in insecticide resistance, pathogen defense and immunity. Additionally, sequences that matched the primary aphid endosymbiont, Buchneraaphidicola, were identified among A. craccivora transcripts. Furthermore, 742, 97, 607 and 180 single nucleotide polymorphisms (SNPs) were respectively predicted among A. curvipes, A. craccivora, C. tomentosicollis and M.sjostedti transcripts, and will likely be valuable tools for future molecular genetic marker development. These results demonstrate that Roche 454-based transcriptome sequencing could be useful for the development of genomic resources for cowpea pest insects in West Africa

    Context and Indigenous Structures for Managing Family Violence in a Yoruba Community

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    Most investigations on domestic violence in family relationships have centered around men as the perpetrators of violence without exploring the context of violence occurrence from a gender lens and other social factors. This study explored the meanings associated with family violence, the contexts for its occurrence, and the indigenous approaches to managing such conflicts among the Yoruba ethnic subgroup in southwest Nigeria. This was an exploratory cross-sectional study guided by an interpretative constructivist approach in which 20 community stakeholders were recruited through purposive sampling. The data were collected via in-depth interview (IDI) and focus group discussion (FGD). Findings from the study showed that both men and women in family relationship contribute to the occurrence of family violence, although the forms perpetrated differ by gender. Religious leaders were identified as key indigenous structure for effective management of family violence among other indigenous structures (extended family mediation and community/royal father interventions). The study showed that these groups of people are also affected by societal male dominance belief which has contributed to occurrence of family violence. The study concluded that an indigenous intervention that will help control family violence among this group must focus on strengthening community structures; most importantly, the religious institutions on how to instill mutual respect among couples and train them on conflict resolution skills as family violence in the group is seen as issue that should not be taken out of the community structures

    Kinetic and isotherm studies on the adsorption–desorption of technical-grade endosulfan in loamy soils under Theobroma cacao L cultivation, Southwestern Nigeria

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    The fate of pesticides in soils is dependent on the adsorption–desorption kinetics, isotherms and soil types. Interactions of technical-grade endosulfan with top soils (top 0–15 cm) from CRIN, Igba and Sore Bale Theobroma cacao L farms in Southwestern Nigeria were studied using the OECD batch isotherm method. The soils were predominately basic (pH 7.1–8.33), while the orders of the total organic carbon (1.32–2.03%) and clay content (10.92–19.11%) were CRIN > Igba > Sore Bale and Igba > CRIN > Sore Bale, respectively. The adsorption of endosulfan was bi-continuous: initially rapid, followed by a slow process, with pseudo-equilibria and plateaus formed between 120 and 240 min. Endosulfan adsorption by soils was due to their greater affinity for organic matter than clay. The adsorption rates fitted better into a pseudo-second-order model (PSOM) than a pseudo-first-order model (PFOM), with the adsorption (kads) and desorption (kdes) rate constants for both isomers ranging from 7.60 × 10−3 to 11.52 × 10−3 min−1 and 1.39 × 10−3 to 3.42 × 10−3 min−1, respectively (i.e. kads > kdes), while kdes (ÎČ-isomer) > kdes (α-isomer) for PFOM, but k2_ads < k2_des for the two isomers in PSOM. Additionally, α-endosulfan was adsorptive, with the ÎČ-isomer more prone to leaching; both isomers were moderately leachable according to their FAO mobility rankings. The adsorption model did not fit well into a Langmuir isotherm (R2 ≀ 0.948); however, the desorption model did (R2 ≄ 0.991). Freundlich isotherm plots fitted better (R2 ≄ 0.992) and exhibited non-linear curves of types L and S for the adsorption and desorption processes, respectively. The adsorption/desorption coefficients (Kfads and Kfdes) and strengths of adsorption/desorption (1/nads and 1/ndes) for both isomers were from 1.33 ± 0.10 to 4.81 ± 0.18 ÎŒg1−1/n (mL)1/n g−1 and 0.503 to 1.402, respectively, in all soils, with Kfads < Kfdes and 1/nads < 1/ndes. Positive hysteresis was observed. CRIN exhibited the highest hysteresis index. The Kfom values were ≀127.14 ± 6.23 mL g−1, while the values of the standard free energy were ΔG0 = −5.11 to −14.05 kJ mol−1 K−1, depicting a spontaneous physisorption process, driven by van der Waals forces, among others. Endosulfan could easily be leached and contaminate the surface and groundwater owing to its faster PSOM desorption rate constant, but TOM and clay could be used as mitigants to reduce its mobility in soils as they have significant affinity for the pesticide

    The spatial genetic differentiation of the legume pod borer, Maruca vitrata F. (Lepidoptera: Crambidae) populations in West Africa

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    The legume pod borer, Maruca vitrata, is an endemic insect pest that causes significant yield loss to the cowpea crop in West Africa. The application of population genetic tools is important in the management of insect pests but such data on M. vitrata is lacking. We applied a set of six microsatellite markers to assess the population structure of M. vitrata collected at five sites from Burkina Faso, Niger and Nigeria. Observed polymorphisms ranged from one (marker 3393) to eight (marker 32008) alleles per locus. Observed and expected heterozygosities ranged from 0.0 to 0.8 and 0.0 to 0.6, respectively. Three of the loci in samples from Nigeria and Burkina Faso deviated significantly from Hardy-Weinberg Equilibrium (HWE), whereas no loci deviated significantly in samples from Niger. Analysis of molecular variance (AMOVA) indicated that 67.3% level of the genetic variation was within individuals compared to 17.3% among populations. A global estimate of FST=0.1 (ENA corrected FST=0.1) was significant (P≀0.05) and corroborated by pairwise FST values that were significant among all possible comparisons. A significant correlation was predicted between genetic divergence and geographic distance between subpopulations (R2=0.6, P=0.04), and cluster analysis by the program STRUCTURE predicted that co-ancestry of genotypes were indicative of three distinct populations. The spatial genetic variance among M. vitrata in West Africa may be due to limited gene flow, south-north seasonal movement pattern or other reproductive barriers. This information is important for the cultural, chemical and biological control strategies for managing M. vitrata

    Performance of aquatic plant species for phytoremediation of arsenic-contaminated water

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    This study investigates the effectiveness of aquatic macrophyte and microphyte for phytoremediation of water bodies contaminated with high arsenic concentration. Water hyacinth (Eichhornia crassipes) and two algae (Chlorodesmis sp. and Cladophora sp.) found near arsenic-enriched water bodies were used to determine their tolerance toward arsenic and their effectiveness to uptake arsenic thereby reducing organic pollution in arsenic-enriched wastewater of different concentrations. Parameters like pH, chemical oxygen demand (COD), and arsenic concentration were monitored. The pH of wastewater during the course of phytoremediation remained constant in the range of 7.3–8.4, whereas COD reduced by 50–65 % in a period of 15 days. Cladophora sp. was found to survive up to an arsenic concentration of 6 mg/L, whereas water hyacinth and Chlorodesmis sp. could survive up to arsenic concentrations of 2 and 4 mg/L, respectively. It was also found that during a retention period of 10 days under ambient temperature conditions, Cladophora sp. could bring down arsenic concentration from 6 to <0.1 mg/L, Chlorodesmis sp. was able to reduce arsenic by 40−50 %; whereas, water hyacinth could reduce arsenic by only 20 %. Cladophora sp. is thus suitable for co-treatment of sewage and arsenic-enriched brine in an algal pond having a retention time of 10 days. The identified plant species provides a simple and cost-effective method for application in rural areas affected with arsenic problem. The treated water can be used for irrigation
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