222 research outputs found

    Dissertation Notices

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    Prevalence, incidence and severity of a new root rot disease of cowpea caused by Macrophomina phaseolina (Tassi) Goid in Northern Ghana

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    Cowpea is an important economic crop in northern Ghana. Following reports of a new cowpea root rot, disease in northern Ghana (Northern, Upper East and Upper West regions), surveys were conducted in 2016 and 2017 with the aim of determining the causal organism, prevalence, incidence and severity of the disease across northern Ghana under rain fed and irrigated conditions. Seventeen locations were surveyed and symptomatic plants were taken to the Plant Pathology laboratory in CSIR- Savanna Agricultural Research Institute (SARI), Nyankpala for pathogen identification. The disease was prevalent in all the locations surveyed. There was no significant difference (P > 0.05) between disease incidence and severity (1‒9 scale) under rain fed and irrigated conditions for each year. Disease incidence and severity were however significantly different (P < 0.05) amongst locations surveyed under both rain fed and irrigated production for 2016 and 2017. Under rain fed conditions for 2016, Nyankpala recorded the highest incidence (43.8%), with Feo recording the lowest (17.8%). For the same period, Manga recorded the highest severity (4.3) with Silbelle recording the least (2.1). Under dry season cultivation for 2016, Asumsapeliga recorded the highest disease incidence (44.5%) with Silbelle recording the lowest (11.4%). Sakpari, however, recorded the highest disease severity (3.8) with Feo recording the lowest for the same period. Under rain fed conditions for 2017, disease incidence was highest in Nyankpala (47.7%) and lowest in Lawra (8.7%). For the same period, however, Manga and Yendi recorded the highest severity (4.3) with Lawra recording the lowest (1.6). Under dry season cowpea production for 2017, Sakpari (64.8%) recorded the highest incidence and Silbelle (7.0%) recording the least. Disease severity for the same period was highest in Nafkluga (4.2) and lowest in Silbelle (2.3). Morphocultural characteristics and pathogenicity test confirmed Macrophomina phaseolina as the causal organism of the cowpea root rot disease

    Genetic Diversification and Selection Strategies for Improving Sorghum Grain Yield Under Phosphorous-Deficient Conditions in West Africa

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    Sorghum, a major crop for income generation and food security in West and Central Africa, is predominantly grown in low-input farming systems with serious soil phosphorus (P) deficiencies. This study (a) estimates genetic parameters needed to design selection protocols that optimize genetic gains for yield under low-phosphorus conditions and (b) examines the utility of introgressed backcross nested association mapping (BCNAM) populations for diversifying Malian breeding materials. A total of 1083 BC1F5 progenies derived from an elite hybrid restorer “Lata-3” and 13 diverse donor accessions were evaluated for yield and agronomic traits under contrasting soil P conditions in Mali in 2013. A subset of 298 progenies were further tested under low-P (LP) and high-P (HP) conditions in 2014 and 2015. Significant genetic variation for grain yield was observed under LP and HP conditions. Selection for grain yield under LP conditions was feasible and more efficient than the indirect selection under HP in all three years of testing. Several of the BCNAM populations exhibited yields under LP conditions that were superior to the elite restorer line used as a recurrent parent. The BCNAM approach appears promising for diversifying the male parent pool with introgression of diverse materials using both adapted Malian breed and unadapted landrace material from distant geographic origins as donors

    Survival rates of head and neck cancers in Ghana: a retrospective study at the Komfo Anokye Teaching Hospital

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    OBJECTIVE: Data was collected to evaluate the survival rates of head and neck (conjunctiva, oropharyngeal and non-oropharyngeal) squamous cell carcinomas in Ghana. DATA DESCRIPTION: We provided data on a retrospective review of 8 years (January 2004 to December 2009) survival rate of head and neck squamous cell carcinomas (HNSCCs) at the Komfo Anokye Teaching Hospital in Ghana. The data consist of patient demographic data and clinicopathological findings which includes tumour site, tumour stage and histological grades of the patients. Clinical outcome measurement was death through to January 2013 on record and confirmed from the hospitals birth and death registry department. More than 85% of death cases were confirmed by gender, age, and folder identification numbers from the birth and death registry

    The modern pollen-vegetation relationship of a tropical forest-savannah mosaic landscape, Ghana, West Africa

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    Transitions between forest and savannah vegetation types in fossil pollen records are often poorly understood due to over-production by taxa such as Poaceae and a lack of modern pollen-vegetation studies. Here, modern pollen assemblages from within a forest-savannah transition in West Africa are presented and compared, their characteristic taxa discussed, and implications for the fossil record considered. Fifteen artificial pollen traps were deployed for 1 year, to collect pollen rain from three vegetation plots within the forest-savannah transition in Ghana. High percentages of Poaceae and Melastomataceae/Combretaceae were recorded in all three plots. Erythrophleum suaveolens characterised the forest plot, Manilkara obovata the transition plot and Terminalia the savannah plot. The results indicate that Poaceae pollen influx rates provide the best representation of the forest-savannah gradient, and that a Poaceae abundance of >40% should be considered as indicative of savannah-type vegetation in the fossil record

    Towards systematic and evidence-based conservation planning for western chimpanzees

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    As animal populations continue to decline, frequently driven by large‐scale land‐use change, there is a critical need for improved environmental planning. While data‐driven spatial planning is widely applied in conservation, as of yet it is rarely used for primates. The western chimpanzee (Pan troglodytes verus) declined by 80% within 24 years and was uplisted to Critically Endangered by the IUCN Red List of Threatened Species in 2016. To support conservation planning for western chimpanzees, we systematically identified geographic areas important for this taxon. We based our analysis on a previously published data set of modeled density distribution and on several scenarios that accounted for different spatial scales and conservation targets. Across all scenarios, typically less than one‐third of areas we identified as important are currently designated as high‐level protected areas (i.e., national park or IUCN category I or II). For example, in the scenario for protecting 50% of all chimpanzees remaining in West Africa (i.e., approximately 26,500 chimpanzees), an area of approximately 60,000 km2 was selected (i.e., approximately 12% of the geographic range), only 24% of which is currently designated as protected areas. The derived maps can be used to inform the geographic prioritization of conservation interventions, including protected area expansion, “no‐go‐zones” for industry and infrastructure, and conservation sites outside the protected area network. Environmental guidelines by major institutions funding infrastructure and resource extraction projects explicitly require corporations to minimize the negative impact on great apes. Therefore, our results can inform avoidance and mitigation measures during the planning phases of such projects. This study was designed to inform future stakeholder consultation processes that could ultimately integrate the conservation of western chimpanzees with national land‐use priorities. Our approach may help in promoting similar work for other primate taxa to inform systematic conservation planning in times of growing threats

    Profiling of cardio-metabolic risk factors and medication utilisation among Type II diabetes patients in Ghana: a prospective cohort study

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    Background: Type II diabetes mellitus (T2DM) is complicated by multiple cardio-metabolic risk factors. Controlling these factors requires lifestyle modifications alongside utilisation of anti-diabetic medications. Different glucose lowering [(biguanides (BIGs), sulfonylureas (SUAs), thiazolidinediones (TNZ)], lipid lowering (statins), and anti-hypertensive medicines [angiotensin converting enzyme inhibitors (ACEIs), calcium channel blockers (CCBs), angiotensin II receptor blockers (ARBs) and central acting drugs (CADs)] have been approved for controlling hyperglycaemia, dyslipidaemia and hypertension respectively. Here, we examined factors that characterise T2DM and explored the response to medication therapy among T2DM patients. Methods: This prospective cohort study recruited 241 T2DM patients reporting at a clinic in Ghana, from January through to August, 2016. Each patient’s demographic, medications and anthropometric data was obtained while information on medication adherence was captured using Morisky adherence scale-8 (MMAS-8). Fasting blood samples were collected for biochemical analysis. Results: The mean age of participants was 57.82 years for baseline and six-month follow-up. Physical activity differed at baseline and follow up (p \u3c 0.05) but not body mass index (BMI). BIG alone, or in combination with SUA and TNZ did not improve glycaemic status at follow up (p \u3e 0.05). Many participants using either ACEI or ARB were able to control their blood pressures. Among dyslipidaemia patients under statin treatment, there was an improved lipid profile at follow-up. Conclusions: Statin medications are effective for reducing dyslipidaemia in T2DM patients. However, control of modifiable risk factors, particularly blood glucose and to a lesser degree blood pressure is suboptimal. Addressing these will require concomitant interventions including education on medication adherence and correct dietary plans, lifestyle modifications and physical activity

    Nanobodies that block gating of the P2X7 ion channel ameliorate inflammation

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    International audienceIon channels are desirable therapeutic targets, yet ion channel-directed drugs with high selectivity and few side effects are still needed. Unlike small-molecule inhibitors, antibodies are highly selective for target antigens but mostly fail to antagonize ion channel functions. Nanobodies-small, single-domain antibody fragments-may overcome these problems. P2X7 is a ligand-gated ion channel that, upon sensing adenosine 5′-triphosphate released by damaged cells, initiates a proinflammatory signaling cascade, including release of cytokines, such as interleukin-1b (IL-1b). To further explore its function, we generated and characterized nanobodies against mouse P2X7 that effectively blocked (13A7) or potentiated (14D5) gating of the channel. Systemic injection of nanobody 13A7 in mice blocked P2X7 on T cells and macrophages in vivo and ameliorated experimental glomerulonephritis and allergic contact dermatitis. We also generated nanobody Dano1, which specifically inhibited human P2X7. In endotoxin-treated human blood, Dano1 was 1000 times more potent in preventing IL-1b release than small-molecule P2X7 antagonists currently in clinical development. Our results show that nanobody technology can generate potent, specific therapeu-tics against ion channels, confirm P2X7 as a therapeutic target for inflammatory disorders, and characterize a potent new drug candidate that targets P2X7

    Introgression of drought tolerance traits into adapted Kenyan chickpea varieties using marker assisted backcrossing (MABC)

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    Drought is the major constraint causing considerable yield reduction in chickpea. Roots play a critical role in enhancing drought tolerance. The main objective of the study was to introgress drought tolerant root traits into Kenyan chickpea varieties through marker assisted breeding (MABC). Eight simple sequence repeat (SSR) markers, linked to quantitative trait loci (QTL) for root and yield traits, were used to screen the parents at ICRISAT, India. In addition, 1144 single nucleotide polymorphic markers (SNPs) were also used in genotyping these parents at Legume Genomics Center, United Kingdom. Crosses were made between two selected varieties, ICCV 92944 (Chania Desi II) and ICCV 00108 (LDT 068) and ‘QTL-hotspot’ donor parent ICC 4958 that has extensive rooting system. Polymor- In the face of increasing water scarcity, breeding for higher transpiration efficiency (TE), that is, the biomass produced per unit of water transpired, has become crucial. This could be achieved by reducing plant transpiration through a better closure of the stomatal pores at the leaf surface. However, this strategy generally also lowers growth, as stomatal opening is necessary for the capture of atmospheric CO2 that feeds daytime photosynthesis. Here, we considered the reduction in transpiration rate at night (En), when photosynthesis is inactive, as a possible strategy to limit water use without altering growth. We carried out a genetic analysis for En and TE in grapevine, a major crop in drought-prone areas. A 3 year experiment was conducted on the F1 progeny from a cross between Syrah and Grenache cultiphic SSR and SNP markers were used to select progenies with root QTL at F1, BC1F1 and BC2F1 that were later advanced to BC2F3. The BC2F3 populations were evaluated for root traits at Egerton University in randomized complete block design with two replications in pot experiment. The BC2F3 families were significantly different for root dry weight (RDW), shoot dry weight (SDW), total plant dry weight (PDW) and root to shoot dry weight (R/S) ratio (R/S) for Chania Desi II x ICC 4958 and R/S for LDT 068 x ICC 4958. These lineshad significantly improved root traits compared the recurrent parents. MABC is aneffective and efficient method of introgressing complex drought tolerant traits which leads to improvement in yield especially under drought conditions
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