115 research outputs found

    Nuclear Fuel Handling Device

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    The fuel handling device project is a solution to help the operators at Rhode Island Nuclear Science Center and Los Alamos National Laboratories ease the transportation and inspection of spent fuel rods. The objective is to have a device or pole that can remove spent fuel assemblies which sit in a 35 foot deep reactor. Which latches onto a small crossbar on top of the fuel assembly which transports it to another side of the reactor. In order to make sure it’s transported safely, there can’t be any errors where the fuel assembly would fall over. A device was created to meet the criteria that was laid out by the workers at RINSC and provide an optimal device for the workers to use. After 120 conceptual ideas and many hours of discussing these options, a final design has been chosen for the device. This includes specific dimensions and materials acceptable for use while also deciding to have an interchangeable end for multi use. Parts have been designed and printed to visualize the optimal end for the fuel handling before purchasing and manufacturing the final product

    Factors Influencing Farmers’ Decision to Adopt Apple Management Practices in Southwestern Highlands, Uganda

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    Worldwide apples account for fifty (50) percent of the world’s deciduous fruit tree production. Despite the benefits that come with apple production, adoption has been slow especially among smallholder farmers in Southwestern Highlands. This present study was therefore conducted to identify apple management practices (AMPs) and also examine the factors influencing farmer decision to adopt AMPs. A multi-stage sampling procedure was employed to select 52 apple growing households in the districts of Kabale, Kisoro, Kanungu and Rukungiri that form Southwestern Highlands. Probit regression model was employed and the estimation procedure followed Maximum Likelihood Estimation (MLE) approach. Results from the descriptive statistics indicated that the most applied management practices included weeding, bending and staking, pesticide application and defoliation among others.  Probit regression results showed that sex of the farmer, average number of fruits per tree, household labor force, farm size and access to credit had a positive and statistically significant effect on farmers’ decision to adopt AMPs (p<0.05) while age of the farmer, orchard location, obstruction by birds and off-farm income source had a negative and statistically significant influence on farmers’ decision to adopt AMPs (p<0.05). In view of the above, there is need to identify and address gender differences in terms of engagement in apple production targeting more women. Research needs to come up with an effective but affordable remedy against pests especially birds, strategies of attracting and maintaining youth into apple farming need to be explored and implemented since apple farming is labor intensive and is dominated by aging farmers, research and extension need to explore appropriate and cost effective avenues for farmers to access credit, accurate and quality agricultural information. Keywords: Adoption, Apples, Probit model, Orchard, Southwestern Highlands DOI: 10.7176/JESD/10-2-14

    A Study on Agricultural Residues as a Substitute to Fire Wood in Kenya: a Review on Major Crops

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    For Kenya, the use of fire wood is enormous that the exploitation of other energy resources such as biomass from agricultural residues is little known. Therefore, the main aim of this study is to investigate agricultural residues estimates for use as a substitute to fire wood and charcoal in Kenya. This solution is in line to the urgent needs of finding the alternative for the depleting fossil fuels. The study found that Kenya agricultural residue energy potential is about 187,000 TJ which enough to substitute fire wood in most regions if converted with suitable technologies. If all the available agricultural residues are used as substitution fuel for fire wood, Kenya could reinstate the 10% forest cover as recommended from the current 1.7%

    Arctic lagoon and nearshore food webs: Relative contributions of terrestrial organic matter, phytoplankton, and phytobenthos vary with consumer foraging dynamics

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    Characterizing energy flow and trophic linkages is fundamental to understanding the functioning and resilience of Arctic ecosystems under increasing pressure from climate change and anthropogenic exploitation. We used carbon and nitrogen stable isotopes to examine trophic dynamics and the relative contribution of terrestrial organic matter, water column phytoplankton, and phytobenthos (benthic micro- and macro-autotrophs as well as sea ice algae) to the food webs supporting 45 macroconsumers in three Arctic coastal lagoon ecosystems (Krusenstern, Sisualik, Akulaaq) and the adjacent Kotzebue Sound with varying degrees of connectivity in Cape Krusenstern National Monument, Alaska. A two-source (water column particulate organic matter and benthic sediment organic matter), two-isotope trophic dynamics model informed by a Bayesian isotope mixing model revealed that the Lagoon-Kotzebue Sound coastal ecosystem supported consumers along a trophic position continuum from primary consumers, including amphipods, copepods, and clams to trophic level five predators, such as seastars, piscivorous fishes, seals, and seabirds. The relative contribution of the three primary producer end members, terrestrial organic matter (41 ± 21%), phytoplankton (25 ± 21%), and phytobenthos (34 ± 23%) varied as a function of: 1) consumer foraging ecology and 2) consumer location. Suspension feeders received most of their carbon from food webs based on phytoplankton (49 ± 11%) and terrestrial organic matter (23 ± 5%), whereas herbivores and detritivores received the majority of their carbon from phytobenthos-based food webs, 58 ± 10% and 60 ± 8%, respectively. Omnivores and predators showed more even distributions of resource reliance and greater overall variance among species. Within the invertebrates, the importance of terrestrial organic matter decreased and phytobenthos increased with increasing trophic position. The importance of terrestrial organic matter contribution increased with lagoon proximity to major rivers inputs and isolation from Kotzebue Sound. Several taxa with cultural and subsistence food importance to local communities showed significant reliance (30–90% of baseline carbon) on food chains linked to fresh terrestrial organic matter. Our study indicates that terrestrial-marine linkages are important to the function of Arctic coastal lagoon ecosystems and artisanal fisheries. These linkages are likely to strengthen in the future with regional changes in erosion and runoff associated with climate change and anthropogenic disturbance

    MeCP2 Regulates the Synaptic Expression of a Dysbindin-BLOC-1 Network Component in Mouse Brain and Human Induced Pluripotent Stem Cell-Derived Neurons

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    Clinical, epidemiological, and genetic evidence suggest overlapping pathogenic mechanisms between autism spectrum disorder (ASD) and schizophrenia. We tested this hypothesis by asking if mutations in the ASD gene MECP2 which cause Rett syndrome affect the expression of genes encoding the schizophrenia risk factor dysbindin, a subunit of the biogenesis of lysosome-related organelles complex-1 (BLOC-1), and associated interacting proteins. We measured mRNA and protein levels of key components of a dysbindin interaction network by, quantitative real time PCR and quantitative immunohistochemistry in hippocampal samples of wild-type and Mecp2 mutant mice. In addition, we confirmed results by performing immunohistochemistry of normal human hippocampus and quantitative qRT-PCR of human inducible pluripotent stem cells (iPSCs)-derived human neurons from Rett syndrome patients. We defined the distribution of the BLOC-1 subunit pallidin in human and mouse hippocampus and contrasted this distribution with that of symptomatic Mecp2 mutant mice. Neurons from mutant mice and Rett syndrome patients displayed selectively reduced levels of pallidin transcript. Pallidin immunoreactivity decreased in the hippocampus of symptomatic Mecp2 mutant mice, a feature most prominent at asymmetric synapses as determined by immunoelectron microcopy. Pallidin immunoreactivity decreased concomitantly with reduced BDNF content in the hippocampus of Mecp2 mice. Similarly, BDNF content was reduced in the hippocampus of BLOC-1 deficient mice suggesting that genetic defects in BLOC-1 are upstream of the BDNF phenotype in Mecp2 deficient mice. Our results demonstrate that the ASD-related gene Mecp2 regulates the expression of components belonging to the dysbindin interactome and these molecular differences may contribute to synaptic phenotypes that characterize Mecp2 deficiencies and ASD.Fil: Larimore, Jennifer. Agnes Scott College; Estados UnidosFil: Ryder, Pearl V.. University of Emory; Estados UnidosFil: Kim, Kun Yong. University of Yale. School of Medicine; Estados UnidosFil: Ambrose, L. Alex. Agnes Scott College; Estados UnidosFil: Chapleau, Christopher. University Of Alabama; Estados UnidosFil: Calfa, Gaston Diego. University Of Alabama; Estados Unidos. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; ArgentinaFil: Gross, Christina. University of Emory; Estados UnidosFil: Bassell, Gary J.. University of Emory; Estados UnidosFil: Pozzo Miller, Lucas. University Of Alabama; Estados UnidosFil: Smith, Yoland. University of Emory; Estados UnidosFil: Talbot, Konrad. The Pennsylvania State University; Estados UnidosFil: Park, In Hyun. University of Yale. School of Medicine; Estados UnidosFil: Faundez, Victor. University of Emory; Estados Unido

    Early management of acute severe UC in the biologics era: development and international validation of a prognostic clinical index to predict steroid response

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    Objectives We aimed to determine whether changes in acute severe colitis (ASC) management have translated to improved outcomes and to develop a simple model predicting steroid non-response on admission. Design Outcomes of 131 adult ASC admissions (117 patients) in Oxford, UK between 2015 and 2019 were compared with data from 1992 to 1993. All patients received standard treatment with intravenous corticosteroids and endoscopic disease activity scoring (Ulcerative Colitis Endoscopic Index of Severity (UCEIS)). Steroid non-response was defined as receiving medical rescue therapy or surgery. A predictive model developed in the Oxford cohort was validated in Australia and India (Gold Coast University Hospital 2015–2020, n=110; All India Institute of Medical Sciences, New Delhi 2018–2020, n=62). Results In the 2015–2019 Oxford cohort, 15% required colectomy during admission vs 29% in 1992–1993 (p=0.033), while 71 (54%) patients received medical rescue therapy (27% ciclosporin, 27% anti-tumour necrosis factor, compared with 27% ciclosporin in 1992–1993 (p=0.0015). Admission C reactive protein (CRP) (false discovery rate, p=0.00066), albumin (0.0066) and UCEIS scores (0.015) predicted steroid non-response. A four-point model was developed involving CRP of ≥100 mg/L (one point), albumin of ≤25 g/L (one point), and UCEIS score of ≥4 (1 point) or ≥7 (2 points). Patients scoring 0, 1, 2, 3 and 4 in the validation cohorts had steroid response rates of 100, 75.0%, 54.9%, 18.2% and 0%, respectively. Scoring of ≥3 was 84% (95% CI 0.70 to 0.98) predictive of steroid failure (OR 11.9, 95% CI 10.8 to 13.0). Colectomy rates in the validation cohorts were were 8%–11%. Conclusions Emergency colectomy rates for ASC have halved in 25 years to 8%–15% worldwide. Patients who will not respond to corticosteroids are readily identified on admission and may be prioritised for early intensification of therapy

    The COVID-19 pandemic in the African continent.

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    In December 2019, a new coronavirus, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and associated disease, coronavirus disease 2019 (COVID-19), was identified in China. This virus spread quickly and in March, 2020, it was declared a pandemic. Scientists predicted the worst scenario to occur in Africa since it was the least developed of the continents in terms of human development index, lagged behind others in achievement of the United Nations sustainable development goals (SDGs), has inadequate resources for provision of social services, and has many fragile states. In addition, there were relatively few research reporting findings on COVID-19 in Africa. On the contrary, the more developed countries reported higher disease incidences and mortality rates. However, for Africa, the earlier predictions and modelling into COVID-19 incidence and mortality did not fit into the reality. Therefore, the main objective of this forum is to bring together infectious diseases and public health experts to give an overview of COVID-19 in Africa and share their thoughts and opinions on why Africa behaved the way it did. Furthermore, the experts highlight what needs to be done to support Africa to consolidate the status quo and overcome the negative effects of COVID-19 so as to accelerate attainment of the SDGs

    Workflow Modelling of Construction Projects

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    This report details the work carried out by the Study Group on workflow modelling of con- struction projects. Data on the progress of about a hundred projects over a single five-year planning period were provided by Heathrow Airport (the client) and their four Tier 1 construction contrac- tors. These data are mapped and analysed. Several unusual features are discovered. For example, most projects undergo several tens of adjustments in their scope and price such that while most projects are technically completed under budget, the price and duration is significantly higher than originally planned. The main question addressed was whether an optimised scheduling of the project would lead to decreased costs and more rapid completion. First, a machine learning approach is used to gain insight onto which factors are most significant in predicting the final cost and duration of each project. If more data were available, these methods could be further exploited to allow for predictions to be made on which projects are likely to over-run or go over budget and to examine connections between projects at the subcontractor level. In addition to the data-centric approach, a complementary mathematical model was de- veloped to gain a better understanding of the effect of resource constraints on cost and price extension due to resource competition of concurrent projects, ignoring the confound- ing effect of scope creep seen in the data. The model takes the form of a discrete time stochastic simulation, whose parameters are fit to the existing data. Tentative conclusions from the model indicate that better outcomes can be achieved by spreading out project start dates, and by prioritising completion of smaller projects. While more data is needed to validate the model, the results suggested that gains can be made if more thoughtful scheduling of projects is implemented, and also if the prioritisation of projects is monitored and adjusted intelligently. Our major recommendation to Heathrow Airport is to collect or retrieve more data, as outlined in the report, so that both models can be made more realistic and useful. This would allow Heathrow Airport and their contractors to develop and test strategies to make the system more efficient, ultimately saving time and money
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