124 research outputs found

    Potential of genomics for the improvement of underutilized legumes in sub-Saharan Africa

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    Open Access Journal; Published online: 03 Jan 2021Underutilized, or orphan legumes, are widely distributed across farming landscapes in sub-Saharan Africa (SSA) but often have low yields and do not fulfill their potential due to very limited research, breeding, development, marketing, and awareness of their benefits. These advantages include nutritional quality and climate resilience. In this review, we focus on Bambara groundnut, African yam bean, and Kersting's groundnut. Knowledge of the challenges and rewards of exploiting them will provide opportunities for concerted approaches to their revival and contribution to future global food systems, especially in the context of climate change. This review identifies the institutional and noninstitutional challenges, the constraints, the prospects, and the rewards that can be derived from exploiting orphan legumes in SSA. The genetic resources center (GRC) of the International Institute of Tropical Agriculture (IITA) conserves a diverse collection of about 2500 accessions of these crops with the majority from Africa. In this review, we focus on the ex situ conservation of the genetic resources of these indigenous African legume crops, their characterization and evaluation, prospects for the development of improved cultivars, and the role they could play, particularly with respect to nutrition and adaptation to climate change. We emphasize progress made in recent years concerning the assembly of information required for application of genomics tools to these crops and how this will underpin the development of improved varieties

    Assessment of performance indices of selected gas turbine power plants in Nigeria

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    In this study, performance assessment of selected gas turbine power plants in Nigeria was evaluated using performance indices. The results of the study showed that for the period under review (2006–2010), the percentage shortfalls from the target energy in the selected power plants range from 26.33% to 86.61% as against the acceptable value of 5–10%. The capacity factor of the selected power plants varies from 16.88% to 73.67% as against the international value of 50–80%. The plant use factor varies from 45.89% to 97.03% and the utilization factor varies from 6.31% to 93.074% as against the international best practice of over 95%. From this result, it can be concluded that the generating units were underutilized. This is due to inadequate routine maintenance and equipment fault development. The analyses of reliability indicators revealed that the mean time between failures varies from 5.42 to 378.44 h, the mean time to repair varies from 18.3 to 153.88 h and the plant availability varies from 12.86% to 91.31% as against the Institute of Electrical and Electronics Engineers recommended standard of 99.9%. Evaluation of operating figures of the selected power plants revealed that starting reliability (SR) and operating reliability vary from 71.95% to 93.9% and 5.33% to 55%, respectively. The SR of the selected power plants is low in value compared with standard value of 99.9%. The statistical analysis carried out on plant availability revealed that at 95% confidence level; there is a significant difference in availability of the selected power plants. This indicates differences in their systems installation, operation and maintenance. The performance indicator developed to evaluate the performance indices for the selected stations can also be applicable to other power stations in Nigeria and elsewhere. Measures to improve the performance indices of the plants have been suggested in this paper

    Genetic Diversity of Plasmodium falciparum Field Isolates from South Western Nigeria

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    Background: Plasmodium falciparum the main causative agent of malaria is an important public health vector. With the use of PCR, its genetic diversity has been extensively studied with dearth information from Nigeria. Methods: In this study, 100 P. falciparum strains merozoite surface protein 1( msp-1), merozoite surface protein 2 (msp-2) and Glutamate rich protein (Glurp) from Ogun State General Hospitals were characterized. The genetic diversity of P. falciparum isolates was analyzed by restriction fragment length polymorphism following gel electrophoresis of DNA products from nested polymerase chain reactions (PCR) of their respective allelic families KI, MAD 20, RO33 (MSP-1);FC27, 3D7 (MSP-2) and Glutamate rich protein respectively. Results: Majority of the patients showed monoclonal infections while multiplicity of the infection for msp-1 and msp-2 were 1.1 and 1.2 respectively. The estimated number of genotypes was 8 msp-1 (4 KI; 3 MAD; 1 RO33) and 6 msp-2 (3 FC27; 3 3D7). 80% of the isolates coded for Glurp with allelic size ranged between 700 and 900 bp. Conclusion: The allelic distributions however were similar to those previously reported in other endemic malaria countries. Future studies will be designed to include other malaria endemic regions of Nigeria such as the oil exploration region

    Orbitofrontal cortex, emotional decision-making and response to cognitive behavioural therapy for psychosis

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    Grey matter volume (GMV) in the orbitofrontal cortex (OFC) may relate to better response to cognitive behavioural therapy for psychosis (CBTp) because of the region's role in emotional decision-making and cognitive flexibility. This study aimed to determine the relation between pre-therapy OFC GMV or asymmetry and CBTp responsiveness and emotional decision-making as measured by the Iowa Gambling Task (IGT). Thirty patients received CBTp + standard care (CBTp+SC; 25 completers) for 6-8 months. All patients (before receiving CBTp) and 25 healthy participants underwent structural magnetic resonance imaging and performed the IGT. Patients' symptoms were assessed before and after therapy. Pre-therapy OFC GMV, measured using a region-of-interest approach, and IGT performance, measured as overall learning, attention to reward, memory for past outcomes and choice consistency, were comparable between patient and healthy groups. In the CBTp+SC group, greater OFC GMV was correlated with positive symptom improvement, specifically hallucinations and persecution. Greater rightward OFC asymmetry correlated with improvement in several negative and general psychopathology symptoms. Greater left OFC GMV was associated with lower IGT attention to reward. The findings suggest that greater OFC volume and rightward asymmetry, which maintain the OFC's function in emotional decision-making and cognitive flexibility, are beneficial for CBTp responsiveness

    Systems thinking : an approach for understanding 'eco-agri-food systems'

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    The TEEBAgriFood ‘Scientific and Economic Foundations’ report addresses the core theoretical issues and controversies underpinning the evaluation of the nexus between the agri-food sector, biodiversity and ecosystem services and externalities including human health impacts from agriculture on a global scale. It argues the need for a ‘systems thinking‘ approach, draws out issues related to health, nutrition, equity and livelihoods, presents a Framework for evaluation and describes how it can be applied, and identifies theories and pathways for transformational change

    Toll-like receptor-2 deficiency enhances non-alcoholic steatohepatitis

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    <p>Abstract</p> <p>Background</p> <p>Previously we reported that mice deficient in toll-like receptor 4 (TLR-4) signalling were protected from diet-induced non-alcoholic steatohepatitis (NASH). Another member of the toll-like receptor family, TLR-2, has been shown to play a role in lipid trafficking via uptake of diacylated lipoproteins. However, a role for TLR-2 in NASH has not been elucidated. The objectives of the current study were to examine the influence of dietary fat quality and TLR-2 on NASH pathogenesis.</p> <p>Methods</p> <p>Steatohepatitis was induced in male Db, C57BL/6 and TLR-2<sup>-/- </sup>mice by feeding an L-amino acid-defined diet that was deficient in methionine and choline (MCDD). Mice fed the base diet supplemented with methionine and choline (control diet; CD) were used as controls. To determine the role of fat quality, MCDD was enriched with polyunsaturated corn oil (PUFA) or coconut oil that is comprised mostly of saturated fat (SAFA); the total amount of each fat was 112.9 g/kg of diet. After 8 weeks of feeding CD or MCDD, hepatic steatosis, inflammation and necrosis were evaluated in histological sections. Total RNA was extracted from frozen liver samples and mRNA expression of TNFα, collagen α1, IL-10, peroxisome proliferator-activated receptor-γ (PPAR-γ), TLR-4, and CD14, was analyzed via real-time PCR. Protein levels of TLR-2 were analyzed by western blot.</p> <p>Results</p> <p>Panlobular macrovessicular steatosis and diffuse leukocyte infiltration were noted in PUFA-fed Db mice. Histological scores demonstrated significantly less steatosis, inflammation and necrosis in SAFA-fed mice of all mouse strains. However, compared to wild type mice, hepatocellular damage was notably more severe in TLR-2<sup>-/- </sup>mice. Consistent with histological findings, mRNA expression of TNFα was elevated by approximately 3-fold in TLR-2<sup>-/- </sup>mice; PPAR-γ expression was blunted in this strain compared to wild type. Expression of the matrix protein collagen αI was also significantly higher in TLR-2<sup>-/- </sup>mice, indicating a pro-fibrogenic state. Sensitivity to steatohepatitis due to dietary fat or TLR-2 deficiency correlated significantly with alterations in the expression of TLR-4 as well as the co-receptor CD-14.</p> <p>Conclusions</p> <p>Our findings suggest that dietary saturated fat plays a protective role against MCDD-induced steatohepatitis, whereas TLR-2 deficiency exacerbated NASH. The mechanism underlying the response to dietary fat and TLR-2 likely involves altered signalling via the TLR-4 pathway.</p
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