701 research outputs found

    Effect of Gamma Irradiation on Chlorophyll Content in the Cowpea (Vigna unguiculata (L.) Walp)

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    The experiment was conducted to study the mutagenic effect of gamma rays on chlorophyll content at three different physiological stages in the cowpea: pre-flowering, flowering and post-flowering. Five sets of cowpea seeds were subjected to individual doses of gamma rays: 400 Gy, 450 Gy, 500 Gy, 600 Gy and 0 Gy. The seeds were sown to raise the M1 generation. The M1 generation seeds were collected and sown in the next season to raise the M2 generation. Leaf chlorophyll content was measured for M2 generation plants. Mean chlorophyll content for pre-flowering stage ranged between 38.9 ± 8.17 (control) and 64.2 ± 6.16 (400 Gy). Flowering stage mean chlorophyll content ranged from 48.3 ± 14.4 (600 Gy) to 99.4 ± 6.22 (450 Gy). Post-harvest chlorophyll mean content ranged between 13.1 Â±0.98 (600 Gy) and 38.0 ±1.90 (400 Gy). There were significant differences in treatment effects for pre-flowering (P = 0.021), flowering (P = 0.005) and harvest (P = 0.000). At pre-flowering treatment, treatment 400 Gy scored a significant increase of 64 percent (P = 0.02) above the control. The optimum dose for useful induced mutation for increases in chlorophyll concentration in the cowpea was 400 Gy

    SSR-Based Genetic Structure Study of Seventy-Eight Cowpea (Vigna unguiculata (L.) Walp) Genotypes

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    Seventy-eight cowpea accessions were studied using short sequence repeats (SSR) technique. Genetic structure of these accessions was studied using three SSR polymorphic primers, SSR-6206, SSR-6218 and SSR-6219. A total of eight loci were scored for the three primers with a total of ten alleles. Bayesian clustering method grouped the cowpea genotypes into 4 sub-populations. Ancestral allele frequencies ranged between 0.128 and 0.802, while allele frequencies within sub-populations ranged from 0.001 and 0.997. Allele frequency divergence among sub-populations ranged from 0.145 to 0.406. Expected heterozygosity between individuals in the same sub-population ranged from 0.084 and 0.26, Mean genetic differentiation among sub-populations ranged from 0.374 and 0.687, with a mean geneflow ranging from 0.228 and 0.837. There was relative uniformity within the sub-populations which can be accounted for by independent random genetic drift

    Land Use / Land Cover Change And Impact On Carbon Stocks In The Atacora Chain Of Mountains, A Biodiversity Hotspot In Benin (West Africa)

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    Mountain areas are fragile ecosystems that play important roles in people’s livelihoods and maintenance of the global ecosystem through the provision of many ecosystem services. Land use/cover (LULC) change is considered one of the major threats to mountain areas due to its effects on ecosystem services including carbon stocks. In this study we assessed LULC change between 1987 and 2015 and its impact on aboveground carbon stocks in the Atacora Chain of Mountains (ACM) in Benin, West Africa. Supervised classification was performed to delineate LULC classes on three dates (1987, 2001 and 2015), and forest measurements carried out in the land cover classes, to estimate the aboveground biomass and the subsequent carbon stocks. Seven land cover classes were delineated: gallery forests, woodlands, savanna, water, settlements, bare lands and farm lands. LULC changes were characterized by three transitions: 1) the change of man-made land cover into savanna, 2) the change of natural vegetation into man-made land cover and 3) the degradation of gallery forests and woodland into less wooded vegetation. The aboveground carbon stock in gallery forests, woodland and tree savanna were significantly greater than in shrub savanna. During the 28 years of assessment, LULC change in gallery forests, woodland and savanna caused an estimated overall aboveground carbon release of 17.10% in the ACM. From the aboveground carbon quantity in the ACM, it appeared that this ecosystem is a potential carbon reservoir. Because the aboveground carbon stock in shrub savanna is significantly lower as compared to gallery forests, woodland and tree savanna and the rates of degradation from gallery forests and woodland to savanna are high, 53.62% and 59.99% respectively in 28 years, LULC change may undermine the ACM ability to store carbon and contribute to climate change mitigation. There is a need to investigate the drivers of this degradation for actions to preserve the natural vegetation in the ACM. Keywords: Atacora Chain of Mountains; Land use/land cover (LULC); Benin; West Africa; Carbon stock DOI: 10.7176/JEES/10-6-13 Publication date:June 30th 202

    Genotypic and phenotypic diversity of Mycobacterium tuberculosis complex genotypes prevalent in West Africa

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    Findings from previous comparative genomics studies of the Mycobacterium tuberculosis complex (MTBC) suggest genomic variation among the genotypes may have phenotypic implications. We investigated the diversity in the phenotypic profiles of the main prevalent MTBC genotypes in West Africa. Thirty-six whole genome sequenced drug susceptible MTBC isolates belonging to lineages 4, 5 and 6 were included in this study. The isolates were phenotypically characterized for urease activity, tween hydrolysis, Thiophen-2-Carboxylic Acid Hydrazide (TCH) susceptibility, nitric oxide production, and growth rate in both liquid (7H9) and solid media (7H11 and Lowenstein-Jensen (L-J)). Lineage 4 isolates showed the highest growth rate in both liquid (p = 0.0003) and on solid (L-J) media supplemented with glycerol (p<0.001) or pyruvate (p = 0.005). L6 isolates optimally utilized pyruvate compared to glycerol (p<0.001), whereas L5 isolates grew similarly on both media (p = 0.05). Lineage 4 isolates showed the lowest average time to positivity (TTP) (p = 0.01; Average TTP: L4 = 15days, L5 = 16.7days, L6 = 29.7days) and the highest logCFU/mL (p = 0.04; average logCFU/mL L4 = 5.9, L5 = 5.0, L6 = 4.4) on 7H11 supplemented with glycerol, but there was no significant difference in growth on 7H11 supplemented with pyruvate (p = 0.23). The highest release of nitrite was recorded for L5 isolates, followed by L4 and L6 isolates. However, the reverse was observed in the urease activity for the lineages. All isolates tested were resistant to TCH except for one L6 isolate. Comparative genomic analyses revealed several mutations that might explain the diverse phenotypic profiles of these isolates. Our findings showed significant phenotypic diversity among the MTBC lineages used for this study

    Popular Concepts of Justice and Hybrid Judicial Institutions in Ghana

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    The provision of effective, legitimate and accessible justice is one of the most fundamental public goods expected from a well?governed state. In this article, we compare the legitimacy of three state or state?supported Ghanaian dispute settlement institutions: the magistrate's courts, the Commission on Human Rights and Administrative Justice (CHRAJ) and the land dispute committees of the neo?traditional Customary Land Secretariats (CLSs). It was found that popular beliefs and expectations are predominantly focused on the notion that justice requires a ‘balanced process for establishing the truth’, and that the procedures, codes and remedies used by the magistrate's courts and the CHRAJ were more congruent with these beliefs than those of the CLSs. The findings challenge stereotypes of popular and traditional justice as being primarily about reconciliation or restoration of communal harmony, and suggest that state institutions should be supported in their current development of hybrid and informal kinds of dispute settlement

    Transmission characteristics of heterozygous cases of Creutzfeldt-Jakob disease with variable abnormal prion protein allotypes

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    In the human prion disease Creutzfeldt-Jakob disease (CJD), different CJD neuropathological subtypes are defined by the presence in normal prion protein (PrPC) of a methionine or valine at residue 129, by the molecular mass of the infectious prion protein PrPSc, by the pattern of PrPSc deposition, and by the distribution of spongiform change in the brain. Heterozygous cases of CJD potentially add another layer of complexity to defining CJD subtypes since PrPSc can have either a methionine (PrPSc-M129) or valine (PrPSc-V129) at residue 129. We have recently demonstrated that the relative amount of PrPSc-M129 versus PrPSc-V129, i.e. the PrPSc allotype ratio, varies between heterozygous CJD cases. In order to determine if differences in PrPSc allotype correlated with different disease phenotypes, we have inoculated 10 cases of heterozygous CJD (7 sporadic and 3 iatrogenic) into two transgenic mouse lines overexpressing PrPC with a methionine at codon 129. In one case, brain-region specific differences in PrPSc allotype appeared to correlate with differences in prion disease transmission and phenotype. In the other 9 cases inoculated, the presence of PrPSc-V129 was associated with plaque formation but differences in PrPSc allotype did not consistently correlate with disease incubation time or neuropathology. Thus, while the PrPSc allotype ratio may contribute to diverse prion phenotypes within a single brain, it does not appear to be a primary determinative factor of disease phenotype

    Analysis of drug resistance among difficult-to-treat tuberculosis patients in Ghana identifies several pre-XDR TB cases

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    BACKGROUND: Resistance to tuberculosis (TB) drugs has become a major threat to global control efforts. Early case detection and drug susceptibility profiling of the infecting bacteria are essential for appropriate case management. The objective of this study was to determine the drug susceptibility profiles of difficult-to-treat (DTT) TB patients in Ghana. METHODS: Sputum samples obtained from DTT-TB cases from health facilities across Ghana were processed for rapid diagnosis and detection of drug resistance using the Genotype MTBDRplus and Genotype MTBDRsl.v2 from Hain Life science. RESULTS: A total of 298 (90%) out of 331 sputum samples processed gave interpretable bands out of which 175 (58.7%) were resistant to at least one drug (ANY(r)); 16.8% (50/298) were isoniazid-mono-resistant (INH(r)), 16.8% (50/298) were rifampicin-mono-resistant (RIF(r)), and 25.2% (75/298) were MDR. 24 (13.7%) of the ANY(r) were additionally resistant to at least one second line drug: 7.4% (2 RIF(r), 1 INH(r), and 10 MDR samples) resistant to only FQs and 2.3% (2 RIF(r), 1 INH(r), and 1 MDR samples) resistant to AMG drugs kanamycin (KAN), amikacin (AMK), capreomycin (CAP), and viomycin (VIO). Additionally, there were 4.0% (5 RIF(r) and 2 MDR samples) resistant to both FQs and AMGs. 81 (65.6%) out of 125 INH-resistant samples including INH(r) and MDR had katG-mutations (MT) whereas 15 (12%) had inhApro-MT. The remaining 28 (22.4%) had both katG and inhA MT. All the 19 FQ-resistant samples were gyrA mutants whereas the 10 AMGs were rrs (3), eis (3) as well as rrs, and eis co-mutants (4). Except for the seven pre-XDR samples, no sample had eis MT. CONCLUSION: The detection of several pre-XDR TB cases in Ghana calls for intensified drug resistance surveillance and monitoring of TB patients to, respectively, ensure early diagnosis and treatment compliance

    Self-reported use of anti-malarial drugs and health facility management of malaria in Ghana

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    <p>Abstract</p> <p>Objective</p> <p>To assess the appropriateness of self-reported use of anti-malarial drugs prior to health facility attendance, and the management of malaria in two health facilities in Ghana.</p> <p>Method</p> <p>A structured questionnaire was used to collect data from 500 respondents who were diagnosed clinically and/or parasitologically for malaria at Agogo Presbyterian Hospital and Suntreso Polyclinic, both in the Ashanti Region of Ghana. Collected information included previous use of anti-malarial drugs prior to attending the health facilities, types of drugs used, how the drugs were used, and the sources of the drugs. In addition, the anti-malarial therapy given and outcomes at the two health facilities were assessed.</p> <p>Results</p> <p>Of the 500 patients interviewed, 17% had severe malaria, 8% had moderate to severe malaria and 75% had uncomplicated malaria. Forty three percent of the respondents had taken anti-malarial drugs within two weeks prior to hospital attendance. The most commonly used anti-malarials were chloroquine (76%), sulphadoxine-pyrimethamine (9%), herbal preparations (9%) and amodiaquine (6%). The sources of these medicines were licensed chemical sellers (50%), pharmacies (21%), neighbouring clinics (9%) or "other" sources (20%) including left-over medicines at home. One hundred and sixty three (77%) of the 213 patients who had used anti-malarial drugs prior to attending the health facilities, used the drugs inappropriately. At the health facilities, the anti-malarials were prescribed and used according to the national standard treatment guidelines with good outcomes.</p> <p>Conclusion</p> <p>Prevalence of inappropriate use of anti-malarials in the community in Ghana is high. There is need for enhanced public health education on home-based management of malaria and training for workers in medicine supply outlets to ensure effective use of anti-malaria drugs in the country.</p
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