40 research outputs found

    Characterizing Risk Behaviour of Maize Farmers using the Experimental Gambling Approach: An Empirical Study in Ghana

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    Along the maize value chain in Ghana are a wide range of risks that confront actors; the risk chain actors' face include production and marketing risks. Accordingly, risk management, which has become an integral part of maize value chain activities, is challenged with several factors, some of which are economic, institutional, social and behavioral factors. This study posits that risk preferences/behavior of farm decision-makers in the maize value chain have empirical importance for economic and policy analysis. Thus, an experimental gambling approach was used to elicit the risk aversion behavior of respondents (farmers). Here, the respondents' risk aversion behavior over varying game levels was investigated. The multinomial logit model was used to investigate endogenous and exogenous factors explaining the risk behavior. The data were obtained by interviewing 220 maize farmers who were sampled with a two-stage sampling procedure. This study revealed that most of the farmers in the study area exhibited risk aversion behavior. About 33% of farmers showed extreme risk aversion behavior at the games’ lowest level and increased to 45% as the game level rose. It was also found that sex, age, level of formal education, access to credit, access to the storage facility, household size, farm size and the number of extension visits to the farm significantly explained the risk aversion behavior the maize farmers exhibited. Because farmers are risk-averse and become more risk-averse as stakes become high, any farm innovations to be introduced to them must be implemented gradually, especially with the low-income farmers. It is also critical to make risk mitigation 'handles' available to farmers so that they can rely on them during times of risk

    Electronic waste control and management in Ghana: A critical assessment of the law, perceptions and practices

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    The aim of the study was to assess the impact of Ghana’s hazardous and e-waste control and management Act 917 of 2016 on current e-waste management practices and the level of awareness among key stakeholders (general public, repairers, wholesalers/retailers, recyclers and importers of electronic items) in the Greater Accra Region of Ghana. Both quantitative and qualitative data were collected and examined in this study. Results showed a low level (12%) of awareness among stakeholders on the e-waste legislation. Almost 13% of respondents had been educated on e-waste management. Community engagement and the mass media were the main sources of information on e-waste. Significant associations between background information of respondents and awareness level on ‘Ghana’s Act 917’ were observed. Relative to general e-waste issues, only education and stakeholder showed significant associations with e-waste legislation and management. The main e-waste disposal methods adopted by respondents were disposal at dumpsites (22.7%), repair and reuse (21.1%) and reselling (20.1%). Almost 10% of respondents made changes to their e-waste disposal practices over the past 5 years. These changes were mainly due to the economic benefits derived from reselling e-waste (37.6%) and the perceived adverse impacts of e-waste on the environment (23.9%). Overall, there is the need to intensify awareness on ‘Ghana’s Act 917’, especially issues regarding sustainable e-waste management practices

    Variable levels of drift in tunicate cardiopharyngeal gene regulatory elements.

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    Background: Mutations in gene regulatory networks often lead to genetic divergence without impacting gene expression or developmental patterning. The rules governing this process of developmental systems drift, including the variable impact of selective constraints on different nodes in a gene regulatory network, remain poorly delineated. Results: Here we examine developmental systems drift within the cardiopharyngeal gene regulatory networks of two tunicate species, Corella inflata and Ciona robusta. Cross-species analysis of regulatory elements suggests that trans-regulatory architecture is largely conserved between these highly divergent species. In contrast, cis-regulatory elements within this network exhibit distinct levels of conservation. In particular, while most of the regulatory elements we analyzed showed extensive rearrangements of functional binding sites, the enhancer for the cardiopharyngeal transcription factor FoxF is remarkably well-conserved. Even minor alterations in spacing between binding sites lead to loss of FoxF enhancer function, suggesting that bound trans-factors form position-dependent complexes. Conclusions: Our findings reveal heterogeneous levels of divergence across cardiopharyngeal cis-regulatory elements. These distinct levels of divergence presumably reflect constraints that are not clearly associated with gene function or position within the regulatory network. Thus, levels of cis-regulatory divergence or drift appear to be governed by distinct structural constraints that will be difficult to predict based on network architectur

    Continuous isoprene measurements in a UK temperate forest for a whole growing season: effects of drought stress during the 2018 heatwave

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    Isoprene concentrations were measured at four heights below, within and above the forest canopy in Wytham Woods (UK) throughout the summer of 2018 using custom-built gas chromatographs (the iDirac). These observations were complemented with selected ancillary variables, including air temperature, photosynthetically active radiation (PAR), occasional leaf gas exchange measurements and satellite retrievals of normalized difference vegetation and water indices (NDVI and NDWI). The campaign overlapped with a long and uninterrupted heatwave accompanied by moderate drought. Peak isoprene concentrations during the heatwave-drought were up to a factor of 4 higher than those before or after. Higher temperatures during the heatwave could not account for all the observed isoprene; the enhanced abundances correlated with drought stress. Leaf-level emissions confirmed this and also included compounds associated with ecosystem stress. This work highlights that a more in-depth understanding of the effects of drought stress is required to better characterize isoprene emissions

    Unsupervised High-Dimensional Analysis Aligns Dendritic Cells across Tissues and Species.

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    Dendritic cells (DCs) are professional antigen-presenting cells that hold great therapeutic potential. Multiple DC subsets have been described, and it remains challenging to align them across tissues and species to analyze their function in the absence of macrophage contamination. Here, we provide and validate a universal toolbox for the automated identification of DCs through unsupervised analysis of conventional flow cytometry and mass cytometry data obtained from multiple mouse, macaque, and human tissues. The use of a minimal set of lineage-imprinted markers was sufficient to subdivide DCs into conventional type 1 (cDC1s), conventional type 2 (cDC2s), and plasmacytoid DCs (pDCs) across tissues and species. This way, a large number of additional markers can still be used to further characterize the heterogeneity of DCs across tissues and during inflammation. This framework represents the way forward to a universal, high-throughput, and standardized analysis of DC populations from mutant mice and human patients

    Cognitive Load and Strategic Sophistication

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    Étude de l'écoulement turbulent transitoire dans une conduite

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    Ce travail a pour objectif l'étude du frottement pariétal dans un écoulement turbulent transitoire en conduite. C'est dans ce cadre qu'un dispositif expérimental a été conçu pour étudier l'évolution des profils de vitesse dans un écoulement transitoire. Dans cette étude, l'application réussie de la vélocimétrie ultrasonore Doppler et de la méthode polarographique pour un écoulement turbulent transitoire est présentée. Après une brève présentation de leurs principes, quelques résultats sont présentés

    Assessing knowledge of sickle cell disease and health beliefs on premarital genetic screening among healthcare trainees at a tertiary institution: A cross‐sectional study

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    Abstract Background The uptake of sickle cell trait (SCT) test is challenged by several factors. A community of healthcare professionals educating the public to undergo screening is critical in reducing the disease burden. We investigated knowledge and attitude towards premarital SCT screening among healthcare trainee students who are the next generation of healthcare practitioners. Methods A cross‐sectional design was employed, and quantitative data were collected from 451 female students pursuing healthcare programs at a tertiary institution in Ghana. Descriptive, bivariate, and multivariate logistic regression analysis was performed. Results More than half of the participants were 20–24 years (54.55%) and had good knowledge (71.18%) about sickle cell disease (SCD). Age and school or social media as sources of information were significantly associated with good knowledge about SCD. Students between the age 20–24 (adjusted odds ratio [AOR] = 2.54, confidence interval [CI] = 1.30–4.97) and knowledge (AOR = 2.19, CI = 1.41–3.39) were 3 times and 2 times more likely to have a positive perception about SCD severity. Students who have SCT (AOR = 5.16, CI = 2.46–10.82), whose source of information was family member/friends (AOR = 2.83, CI = 1.44–5.59) and social media (AOR = 4.59, CI = 2.09–10.12) were 5 times, 2 times and 5 times likely to have a positive perception about the susceptibility of SCD. Students whose source of information is school (AOR = 2.06, CI = 1.11–3.81) and who have good knowledge of SCD (AOR = 2.25, CI = 1.44–3.52) were 2 times more likely to have a positive perception about the benefits of testing. Students with SCT (AOR = 2.64, CI = 1.36–5.13) and source of information was social media (AOR = 3.01, CI = 1.36–6.64) were about 3 times more likely to have a positive perception about the barriers to testing. Conclusion Our data shows that high level of SCD knowledge influences positive perceptions about the severity of SCD, the benefits and relatively low barriers to SCT or SCD testing and genetic counseling. Dissemination of SCT, SCD and premarital genetic counseling education should be intensified especially in schools

    Developmental Analysis of Bone Marrow Neutrophils Reveals Populations Specialized in Expansion, Trafficking, and Effector Functions

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    Neutrophils are specialized innate cells that require constant replenishment from proliferative bone marrow (BM) precursors as a result of their short half-life. Although it is established that neutrophils are derived from the granulocyte-macrophage progenitor (GMP), the differentiation pathways from GMP to functional mature neutrophils are poorly defined. Using mass cytometry (CyTOF) and cell-cycle-based analysis, we identified three neutrophil subsets within the BM: a committed proliferative neutrophil precursor (preNeu) which differentiates into non-proliferating immature neutrophils and mature neutrophils. Transcriptomic profiling and functional analysis revealed that preNeu require the C/EBPε transcription factor for their generation from the GMP, and their proliferative program is substituted by a gain of migratory and effector function as they mature. preNeus expand under microbial and tumoral stress, and immature neutrophils are recruited to the periphery of tumor-bearing mice. In summary, our study identifies specialized BM granulocytic populations that ensure supply under homeostasis and stress responses.We thank all members of L.G.N laboratory, the SIgN (Singapore Immunology Network) flow-cytometry team, the SIgN functional genomics team for their assistance with transcriptomics, and the SIgN mouse core facility for their technical help and support. This research was funded by SIgN core funding, A*STAR (Agency for Science, Technology and Research), Singapore.S
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