44 research outputs found

    Participatory Approach to Variety Selection Using Soybean Production in Ghana as a Model

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    In the past, soybean varieties released in Ghana were selected primarily for grain yield potential, earliness, seed viability and low phosphorus tolerance. However, most of these varieties are not resistant to pod shattering, resulting in high grain losses. In order to identify traits farmers consider most important when deciding which soybean varieties to adopt, a participatory variety selection approach was used to evaluate varieties in two locations (Nyankpala and Wa) in the Guinea savanna zone of Ghana during the 2010 and 2011 cropping seasons. Twelve medium and 14 early maturing varieties were evaluated. Farmers’ variety selection criteria and ranking did not differ across locations and gender groups. Additionally, four most preferred traits by farmer (grain yield, pod shattering, earliness and pods per plant) out of 12 traits were considered very important by farmers at both locations. In some instances, farmers’ preference for the best varieties was not exactly in line with researchers’ selection. Best four ranked varieties (TGx 1799-8F, TGx 1834-5E, TGx 1445-3E and TGx 1844-22E) were preferred by farmers because they possess positive attributes such as higher grain yields, resistance to pod shattering, numerically more pods per plant and enhanced ability to control Striga hermonthica. These varieties were later released as Suong-Pungun, Afayak, Songda and Favour, respectively for commercial production throughout Ghana. Consequently, soybean breeders should incorporate farmers’ preferred traits in selecting varieties in the breeding process in order to increase likelihood of adoption of the varieties

    Does psychopathology at admission predict the length of inpatient stay in psychiatry? Implications for financing psychiatric services

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    Background: The debate on appropriate financing systems in inpatient psychiatry is ongoing. In this context, it is important to control resource use in terms of length of stay (LOS), which is the most costly factor in inpatient care and the one that can be influenced most easily. Previous studies have shown that psychiatric diagnoses provide only limited justification for explaining variation in LOS, and it has been suggested that measures such as psychopathology might be more appropriate to predict resource use. Therefore, we investigated the relationship between LOS and psychopathological syndromes or symptoms at admission as well as other characteristics such as sociodemographic and clinical variables. Methods: We considered routine medical data of patients admitted to the Psychiatric University Hospital Zurich in the years 2008 and 2009. Complete data on psychopathology at hospital admission were available in 3,220 inpatient episodes. A subsample of 2,939 inpatient episodes was considered in final statistical models, including psychopathology as well as complete datasets of further measures (e.g. sociodemographic, clinical, treatment-related and psychosocial variables). We used multivariate linear as well as logistic regression analysis with forward selection procedure to determine the predictors of LOS. Results: All but two syndrome scores (mania, hostility) were positively related to the length of stay. Final statistical models showed that syndromes or symptoms explained about 5% of the variation in length of stay. The inclusion of syndromes or symptoms as well as basic treatment variables and other factors led to an explained variation of up to 25%. Conclusions: Psychopathological syndromes and symptoms at admission and further characteristics only explained a small proportion of the length of inpatient stay. Thus, according to our sample, psychopathology might not be suitable as a primary indicator for estimating LOS and contingent costs. This might be considered in the development of future costing systems in psychiatry

    Dissecting human cortical development, evolution and malformation using organoids and single-cell transcriptomics

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    Organoid single-cell genomic atlas uncovers human-specific features of brain development

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    The human brain has undergone substantial change since humans diverged from chimpanzees and the other great apes1,2. However, the genetic and developmental programs that underlie this divergence are not fully understood. Here we have analysed stem cell-derived cerebral organoids using single-cell transcriptomics and accessible chromatin profiling to investigate gene-regulatory changes that are specific to humans. We first analysed cell composition and reconstructed differentiation trajectories over the entire course of human cerebral organoid development from pluripotency, through neuroectoderm and neuroepithelial stages, followed by divergence into neuronal fates within the dorsal and ventral forebrain, midbrain and hindbrain regions. Brain-region composition varied in organoids from different iPSC lines, but regional gene-expression patterns remained largely reproducible across individuals. We analysed chimpanzee and macaque cerebral organoids and found that human neuronal development occurs at a slower pace relative to the other two primates. Using pseudotemporal alignment of differentiation paths, we found that human-specific gene expression resolved to distinct cell states along progenitor-to-neuron lineages in the cortex. Chromatin accessibility was dynamic during cortex development, and we identified divergence in accessibility between human and chimpanzee that correlated with human-specific gene expression and genetic change. Finally, we mapped human-specific expression in adult prefrontal cortex using single-nucleus RNA sequencing analysis and identified developmental differences that persist into adulthood, as well as cell-state-specific changes that occur exclusively in the adult brain. Our data provide a temporal cell atlas of great ape forebrain development, and illuminate dynamic gene-regulatory features that are unique to humans. This dataset includes the expression and metadata matrices of the constructed pseudocells used in the study

    Organoid single-cell genomic atlas uncovers human-specific features of brain development

    No full text
    The human brain has undergone substantial change since humans diverged from chimpanzees and the other great apes1,2. However, the genetic and developmental programs that underlie this divergence are not fully understood. Here we have analysed stem cell-derived cerebral organoids using single-cell transcriptomics and accessible chromatin profiling to investigate gene-regulatory changes that are specific to humans. We first analysed cell composition and reconstructed differentiation trajectories over the entire course of human cerebral organoid development from pluripotency, through neuroectoderm and neuroepithelial stages, followed by divergence into neuronal fates within the dorsal and ventral forebrain, midbrain and hindbrain regions. Brain-region composition varied in organoids from different iPSC lines, but regional gene-expression patterns remained largely reproducible across individuals. We analysed chimpanzee and macaque cerebral organoids and found that human neuronal development occurs at a slower pace relative to the other two primates. Using pseudotemporal alignment of differentiation paths, we found that human-specific gene expression resolved to distinct cell states along progenitor-to-neuron lineages in the cortex. Chromatin accessibility was dynamic during cortex development, and we identified divergence in accessibility between human and chimpanzee that correlated with human-specific gene expression and genetic change. Finally, we mapped human-specific expression in adult prefrontal cortex using single-nucleus RNA sequencing analysis and identified developmental differences that persist into adulthood, as well as cell-state-specific changes that occur exclusively in the adult brain. Our data provide a temporal cell atlas of great ape forebrain development, and illuminate dynamic gene-regulatory features that are unique to humans. This dataset includes the expression and metadata matrices of the constructed pseudocells used in the study

    Characteristics and storage performance of eight onion cultivars

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    No Abstract Available Ghana J. Sci, Vol.40 2000: 9-1

    Improving Marketable Quality of Tomato: a Simulation of Shipping Conditions in Ghana

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    Aim: The study assessed the influence of a sequence of anticipated hazard elements (impact, compression, vibration) and shipment conditions on marketable quality under varying temperatures and ripeness stages. Study Design: The vibration test simulates a truck operating at highway speed and determines the ability of shipping units to withstand vertical and compression forces resulting from stacking during transport. Storage at 30ÂșC depicted ambient conditions; 15 and 20ÂșC are optimum temperatures for ripening; and pink and light-red ripeness depict typical harvest maturity in Ghana. Place and Duration of Study: The study was conducted at the Postharvest Science Laboratory of the Horticultural Sciences Department of the University of Florida from September to December 2011. Methodology: Round-type tomato at pink and light-red ripeness were subjected to a vibration test and incubated in ripening chambers set at 15, 20 and 30ÂșC. Critical data was taken on days to red-ripe, CO2, ethylene production, color, firmness, weight loss, pH, titratable acidity and soluble solids content. Results: Overall, the influence of vibration and ripeness on marketable shelf life was marginal; however temperature significantly (P≀0.05) influenced shelf life. Vibration increased weight loss, respiration and ethylene production, which were plummeted at lower temperature. Days to red-ripe indicated that tomato should preferably be marketed by 2-4, 8-12 and 10-15 days at 30, 20 and 15ÂșC respectively, at pink to light-red ripeness under current distribution conditions. Best chemical properties were maintained at 15 and 20ÂșC; vibration and ripeness did not influence chemical properties, but increasing temperature affected all physico-chemical properties. Conclusion: The study concludes that despite the cumbersome shipping conditions, tomatoes could be marketed at premium quality if lower storage temperatures were accessible. These facilities are beyond the purchasing power of small-holder traders, thus the involvement of the State and/or Private Sector to providing these facilities would be beneficial; particularly in urban markets where retail prices will merit such investments

    Soil Amendments and Rotation Effects on Soybean and Maize Growths and Soil Chemical Changes in Northern Ghana

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    A four-year field trial was conducted at Bonia in the Upper East Region of Ghana to evaluate soybean-maize rotation amendment systems. The treatments included soybean without amendment, inoculated soybean, inoculated soybean with fertisol, inoculated soybean with phosphorus and potassium (P, K), inoculated soybean with P, K and fertisol, inoculated soybean with nitrogen, phosphorus, and potassium (N, P, K), and continuous maize. Treatments were arranged in a randomized complete block design with four replications. Inoculation negatively affected yields by 2% and 14% in 2013 and 2015, respectively. Soil amendments with P, K or N, P, K increased yields within 45–51%, fertisol increased by 95%, and integration of P, K and fertisol recorded 76% increment of inoculated soybean. Yields of maize increased by 1%, 20%, 25%, 43%, 44%, and 46% under inoculated soybean, inoculated soybean with N, P, K, inoculated soybean with P, K, inoculated soybean with fertisol, soybean without amendment, and inoculated soybean with P, K and fertisol, respectively. Maize after inoculated soybean with fertisol and maize after inoculated soybean with P, K and fertisol consistently scored higher benefit-cost ratio across the two years of experimentation. Thus, the two systems are conceivable for recommendation to the farmers in northern Ghana

    Human stem cell resources are an inroad to Neandertal DNA functions

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    Induced pluripotent stem cells (iPSCs) from diverse humans offer the potential to study human functional variation in controlled culture environments. A portion of this variation originates from ancient admixture between modern humans and Neandertals, which introduced alleles that left a phenotypic legacy on individual humans today. Here we show that a large iPSC repository harbors extensive Neandertal DNA, including alleles that contribute to human phenotypes and diseases, encode hundreds of amino acid changes, and alter gene expression in specific tissues. We provide a database of the inferred introgressed Neandertal alleles for each individual iPSC line, together with the annotation of the predicted functional variants. We also show that transcriptomic data from organoids generated from iPSCs can be used to track Neandertal-derived RNA over developmental processes. Human iPSC resources provide an opportunity to experimentally explore Neandertal DNA function and its contribution to present-day phenotypes, and potentially study Neandertal traits
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