112 research outputs found

    Intestinal ameliorative effects of traditional Ogi-tutu, Vernonia amygdalina and Psidium guajava in mice infected with Vibrio cholera.

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    Background: Cholera, a severe acute watery diarrhea caused by Vibrio cholerae is endemic in Nigeria with most cases occurring in the rural areas. In South West Nigeria, some individuals resort to alternative treatments such as Ogi-tutu, Psidium guajava and Vernonia amygdalina during infections. The effectiveness of these alternatives in the prevention and treatment of V. cholerae infection requires experimental investigation. Objective: This study was designed to investigate the ameliorative effects of Ogi-tutu, Vernonia amygdalina and Psidium guajava on intestinal histopathology of experimental mice infected with V. cholerae. Methods: Preliminary investigation of in vitro vibriocidal activities of these alternatives were carried out using agar cup diffusion assay. For ameliorative effects, adult mice were inoculated with 100 \u3bcl (106 cells) of Vibrio cholerae and dosed at 0 h (immediate prevention) and 4 h (treatment of infection) and their intestines were histopathologically evaluated. Results: The histopathological changes were the same irrespective of the treated groups, but the lesions varied in extent and severity. The ameliorative effects in decreasing order were V. amygdalina > P. guajava > Ogi-tutu. Conclusion: V. amygdalina gave the best ameliorative effects in the prevention and treatment of V. cholerae infection

    Genetic analysis of grain yield and resistance of extra-early-maturing maize inbreds to northern corn leaf blight

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    Open Access Article; Published online: 11 Feb 2021Maize (Zea mays L.) is a food security crop in sub-Saharan Africa (SSA). Incidence of northern corn leaf blight (NCLB), caused by Exserohilum turcicum, in lowlands of SSA during the past decade has caused 30–70% reduction in maize yield. This study (a) examined the combining abilities of extra-early maize (EEM) inbreds and classified them into heterotic groups; (b) elucidated gene action controlling resistance to NCLB; (c) assessed grain yield (GYLD) and yield stability of EEM hybrids underNCLB infection; and (d) identified testers. One hundred and fiftyEEMhybrids, obtained by crossing 15 inbreds each of white- and yellow-endosperm maize using the North Carolina Design II, plus six checks, were evaluated in nine environments, six of which were inoculated with an isolate of E. turcicum and three of which were non-inoculated in 2018 and 2019. The white and yellow inbreds were placed in three heterotic groups using the heterotic grouping based on general combining ability (GCA) of multiple traits and stability of GYLD using the genotype plus genotype × environment (GGE) biplot analysis. The GCA, specific combining ability (SCA) and genotype × environment (G×E) interactions were significant for GYLD, disease severity, and other measured traits. The GCA effects were more important than the SCA effects for GYLD and NCLB severity scores across environments, implying that recurrent selection could facilitate improvement for GYLD and NCLB resistance. Three inbred testers and four single-cross testers were identified for developing high-yielding NCLB-resistant hybrids. Four white and five yellow single-cross hybrids were identified for on-farm testing and possible commercialization

    Spouted bed dried Rosmarinus officinalis extract: a novel approach for physicochemical properties and antioxidant activity

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    In this study, a conical-cylindrical spouted bed dryer with TeflonŸ beads as spouting material was used for producing powdered rosemary (Rosmarinus officinalis L.) extract. The influence of the inlet drying gas temperature (Tgi) and the percentage ratio between the feed rate of concentrated liquid extract by the maximum evaporation capacity of the spouted bed (Ws/Wmax) on selected physicochemical properties of the finished products were investigated. Antioxidant properties of the concentrated liquid extract and dried extracts were also evaluated by the 2.2-diphenyl-1-picrylhydrazyl radical scavenging (DPPH) and lipid peroxidation induced by Fe2+/citrate (LPO) methods; and compared with the values obtained for a lyophilized extract (used as a control). Colloidal silicon dioxide (TixosilŸ 333) and maltodextrin (DE 14) at a 2:1 ratio was added to the concentrated extract before drying (4.4% w/w) to improve the drying performance. The drying variables Ws/Wmax and Tgi have statistically significant influence on total polyphenols and total flavonoid contents of the dried powders. The concentrated extract (on dry basisbeing absolute solid content) showed superior antioxidant activity (AA) compared to both the spouted bed dried and the lyophilized extracts; exhibiting IC50 values of 0.96 ± 0.02, 2.16 ± 0.04 and 3.79 ± 0.05 ”g mL1 (DPPH method) and 0.22 ± 0.01, 1.31± 0.01 and 2.54 ± 0.02 ”g mL1 (LPO method), respectively. These results of AA are comparable to values obtained for quercetin, a flavonoid compound often used as a reference standard due to its potent antioxidant activity; with IC50 of 1.17 ”g mL1 (DPPH) and 0.22 ”g mL1 (LPO). However, the dried rosemary extracts are about 13.5 times more concentrated than the initial concentrated extract (dry weight), with a concentration of total flavonoids and polyphenols compounds ranging from 4.3 to 12.3 and from 1.2 to 4.7 times higher than the concentrated extract values (wet basis). The AA per dry product mass was thus significantly higher than the values measured for concentrated extractive solution, irrespective of some losses of AA apparently due to the drying process.Foundation of Research Support of the São Paulo State (FAPESP) for the funded projects 2011/10333-1, 2012/03427-2 and 2018/26069-0 and for the National Council for Scientific and Technological Development (CNPq) for the financial support. E.B.S. acknowledges the Portuguese Science and Technology Foundation (FCT) for the funded projects M-ERA-NET/0004/2015 (PAIRED) and UIDB/04469/2020 (strategic fund)info:eu-repo/semantics/publishedVersio

    Kolaviron was protective against sodium azide (NaN 3 )induced oxidative stress in the prefrontal cortex

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    Kolaviron is a phytochemical isolated from Garcina kola (G. kola); a common oral masticatory agent in Nigeria (West Africa). It is a bioflavonoid used - as an antivi- ral, anti-inflammatory and antioxidant - in relieving the symp- toms of several diseases and infections. In this study we have evaluated the neuroprotective and regenerative effect of kolaviron in neurons of the prefrontal cortex (Pfc) before or after exposure to sodium azide (NaN 3 ) induced oxidative stress. Separate groups of animals were treated as follows; kolaviron (200 mg/Kg) for 21 days; kolaviron (200 mg/Kg for21days)followedbyNaN 3 treatment (20 mg/Kg for 5days);NaN 3 treatment (20 mg/Kg for 5 days) followed by kolaviron (200 mg/Kg for 21 days); 1 ml of corn-oil (21 days- vehicle); NaN 3 treatment (20 mg/Kg for 5 days). Exploratory activity associated with Pfc function was assessed in the open field test (OFT) following which the microscopic anatomy of the prefrontal cortex was examined in histology (Haematoxylin and Eosin) and antigen retrieval Immunohis- tochemistry to show astroglia activation (GFAP), neuronal metabolism (NSE), cytoskeleton (NF) and cell cycle dysreg- ulation (p53). Subsequently, we quantified the level of Glucose-6-phosphate dehydrogenase (G6PDH) and lactate dehydrogenase (LDH) in the brain tissue homogenate as a measure of stress-related glucose metabolism. Kolaviron (Kv) and Kolaviron/NaN 3 treatment caused no prominent change in astroglia density and size while NaN 3 and NaN 3 / Kv induced astroglia activation and scar formation (astrogliosis) in the Pfc when compared with the control. Sim- ilarly, Kolaviron and Kv/NaN 3 did not alter NSE expression (glucose metabolism) while NaN 3 and NaN 3 /Kv treatment increased cortical NSE expression; thus indicating stress related metabolism. Further studies on enzymes of glu- cose metabolism (G6PDH and LDH) showed that NaN 3 increased LDH while kolaviron reduced LDH in the brain tissue homogenate (P<0.001). In addition kolaviron treatment before (P<0.001) or after ( P <0.05) NaN 3 treatment also reduced LDH expression; thus supporting its role in suppression of oxidative stress. Interestingly, NF deposition increased in the Pfc after kolaviron treatment while Kv/NaN 3 showed no sig- nificant change in NF when compared with the control. In furtherance, NaN 3 and NaN 3 /Kv caused a decrease in NF deposition (degeneration). Ultimately, the protective effect of KV administered prior to NaN 3 treatment was confirmed through p53 expression; which was similar to the control. However, NaN 3 and NaN 3 /Kv caused an increase in p53 expression in the Pfc neurons (cell cycle dysregulation). We conclude that kolaviron is not neu- rotoxic when used at 200 mg/Kg BW. Furthermore, 200 mg/Kg of kolaviron administered prior to NaN 3 treatment (Kv/NaN 3 ) was neuroprotective when com- pared with Kolaviron administered after NaN 3 treatment (NaN 3 /Kv). Some of the observed effects of kolaviron administered before NaN 3 treatment includes reduction of astroglia activation, absence of astroglia scars, anti- oxidation (reduced NSE and LDH), prevention of neu- rofilament loss and cell cycle regulatio

    Cost engineering for manufacturing: current and future research

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    The article aims to identify the scientific challenges and point out future research directions on Cost Engineering. The research areas covered in this article include Design Cost; Manufacturing Cost; Operating Cost; Life Cycle Cost; Risk and Uncertainty management and Affordability Engineering. Collected information at the Academic Forum on Cost Engineering held at Cranfield University in 2008 and further literature review findings are presented. The forum set the scope of the Cost Engineering research, a brainstorming was held on the forum and literatures were further reviewed to understand the current and future practices in cost engineering. The main benefits of the article include coverage of the current research on cost engineering from different perspectives and the future research areas on Cost Engineering

    Estimating genetic gains for tolerance to stress combinations in tropical maize hybrids

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    Open Access Journal; Published online: 08 Dec 2022Maize is a strategic food crop in sub-Saharan Africa. However, most maize growing tropical savannas particularly in West and Central African experience the occurrence of frequent droughts and Striga infestation, resulting in 30–100% yield losses. This production zones need maize cultivars that combine tolerance to the two stresses. IITA in collaboration with national partners has thus employed a sequential selection scheme to incorporate both drought tolerance and Striga resistance in topical maize hybrids using reliable screening protocols. The main objective of the present study was therefore to use grain yield and other agronomic traits recorded in regional collaborative hybrid trials conducted for 8 years under manged stressful and non-stressful conditions and across rainfed field environments to estimate genetic gains in grain yields using mixed model analyses. The results showed significant (p < 0.05) annual yield gains of 11.89 kg ha−1 under manged drought stress (MDS) and 86.60 kg ha−1 under Striga infestation (STRIN) with concomitant yield increases of 62.65 kg ha−1 under full irrigation (WW), 102.44 kg ha−1 under Striga non-infested (STRNO) conditions and 53.11 kg ha−1 across rainfed field environments. Grain yield displayed significant but not strong genetic correlation of 0.41 ± 0.07 between MDS and STRIN, indicating that gene expression was not consistent across the two stress conditions. Furthermore, grain yield recorded in MET had significant moderate genetic correlations of 0.58 ± 0.06 and 0.44 ± 0.07It with MDS and STRIN, respectively. These results emphasize the need to screen inbred linens under both stress conditions to further enhance the rate of genetic gain in grain yield in hybrids for areas where the two stresses co-occur. Nonetheless, this study demonstrated that the sequential selection scheme has been successful in generating hybrids with dependable yields that can reduce chronic food deficits in rural communities experiencing simultaneous presence of drought and S. hermonthica infestation in their production fields

    Predictors of early sexual initiation among a nationally representative sample of Nigerian adolescents

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    <p>Abstract</p> <p>Background</p> <p>Early sexual debut among adolescents is associated with considerable negative heath and development outcomes. An understanding of the determinants or predictors of the timing of sexual debut is important for effective intervention, but very few studies to date have addressed this issue in the Nigerian context. The aim of the present study is to examine predictors of adolescent sexual initiation among a nationally representative sample of adolescents in Nigeria.</p> <p>Methods</p> <p>Interviewer-collected data of 2,070 never-married adolescents aged 15–19 years were analysed to determine association between age of sexual debut and demographic, psychosocial and community factors. Using Cox proportional hazards regression multivariate analysis was carried out with two different models – one with and the other without psychosocial factors. Hazard ratio (HR) and 95% confidence interval (CI) were calculated separately for males and females.</p> <p>Results</p> <p>A fifth of respondents (18% males; 22% females) were sexually experienced. In the South 24.3% males and 28.7% females had initiated sex compared to 12.1% of males and 13.1% females in the North (p < 0.001). In the first model, only region was significantly associated with adolescent sexual initiation among both males and females; however, educational attainment and age were also significant among males. In the second (psychosocial) model factors associated with adolescent sexual debut for both genders included more positive attitudes regarding condom efficacy (males: HR = 1.28, 95% CI = 1.07–1.53; females: HR = 1.24, 95% CI = 1.05–1.46) and more positive attitudes to family planning use (males: HR = 1.19, 95% CI = 1.09–1.31; females: HR = 1.18, 95% CI = 1.07–1.30). A greater perception of condom access (HR = 1.42, 95% CI = 1.14–1.76) and alcohol use (HR = 1.90, 95% CI = 1.38–2.62) among males and positive gender-related attitudes (HR = 1.13, 95% CI = 1.04–1.23) among females were also associated with increased likelihood of adolescent sexual initiation. Conversely, personal attitudes in favour of delayed sexual debut were associated with lower sexual debut among both males (males: HR = 0.36, 95% CI = 0.25–0.52) and females (HR = 0.38, 95% CI = 0.25–0.57). Higher level of religiosity was associated with lower sexual debut rates only among females (HR = 0.59, 95% CI = 0.37–0.94).</p> <p>Conclusion</p> <p>Given the increased risk for a number of sexually transmitted health problems, understanding the factors that are associated with premarital sexual debut will assist programmes in developing more effective risk prevention interventions.</p

    Women’s mass media exposure and maternal health awareness in Ota, Nigeria

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    Maternal health has been an issue of priority to nations across the globe for years now. This study sought to: identify the sources of maternal health awareness; examine means of obtaining maternal health information; determine the frequency of mass media exposure; and analyse the influence of mass media exposure on maternal health awareness among the female residents. The Agendasetting theory and the descriptive (survey) research design, using the questionnaire as the research instrument, were utilized in this study. For this study, the purposive and haphazard sampling techniques were used. The internet (49%) was the topmost source of maternal health awareness; adverts/campaigns (30.6%) were the most common means of obtaining maternal health information; once in a month [27.6%] was the exposure frequency of most participants to the mass media while the least exposure frequency was once in two weeks [5.1%]. It was discovered that mass media exposure had a significant influence on maternal health awareness
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