142 research outputs found

    Differences Between Schools of Choice and Traditional Comprehensive Schools in Their Grade 9 Academic Performance

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    This study was conducted to determine the differences between schools of choice and traditional comprehensive high schools in terms of their Grade 9 State of Texas Assessments of Academic Readiness (STAAR) End-of-Course (EOC) exams in Biology, English 1, and Algebra 1 during the 2017-2018 school year. Inferential statistical analyses revealed the presence of a statistically significant difference between the two types of schools on their EOC exam passing rates in all three content areas for students who were not at-risk and for students who were not in poverty. In contrast, statistically significant differences were not revealed between the two types of schools in terms of the EOC exam passing rates of their CATE and Non-CATE students. Knowing that students who have choice appear to perform better academically, policymakers are encouraged to study the feasibility of channeling more funding to help school districts expand their school choice programs to (a) motivate more students to find the school that fit their needs and their future college and career aspirations, and (b) to solicit more support from parents and community businesses to invest in their communities to improve schools through taxes.  Given that the data for this research were gathered for only 16 school districts in South Texas, researchers are encouraged to conduct a study that will involve all school districts in the whole state and possibly the whole nation to reach more conclusive evidence on the differences between schools of choice and neighborhood schools

    Assessing antibiotic sorption in soil: a literature review and new case studies on sulfonamides and macrolides

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    The increased use of veterinary antibiotics in modern agriculture for therapeutic uses and growth promotion has raised concern regarding the environmental impacts of antibiotic residues in soil and water. The mobility and transport of antibiotics in the environment depends on their sorption behavior, which is typically predicted by extrapolating from an experimentally determined soil-water distribution coefficient (K(d)). Accurate determination of K(d) values is important in order to better predict the environmental fate of antibiotics. In this paper, we examine different analytical approaches in assessing K(d) of two major classes of veterinary antibiotics (sulfonamides and macrolides) and compare the existing literature data with experimental data obtained in our laboratory. While environmental parameters such as soil pH and organic matter content are the most significant factors that affect the sorption of antibiotics in soil, it is important to consider the concentrations used, the analytical method employed, and the transformations that can occur when determining K(d) values. Application of solid phase extraction and liquid chromatography/mass spectrometry can facilitate accurate determination of K(d) at environmentally relevant concentrations. Because the bioavailability of antibiotics in soil depends on their sorption behavior, it is important to examine current practices in assessing their mobility in soil

    Performance of geosynthetics as reinforcement in unpaved roads

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    O trabalho teve como objetivo avaliar o comportamento de estradas não pavimentadas construídas sobre solos moles reforçadas com diferentes geossintéticos. Foram selecionadas três estradas não pavimentadas que apresentassem um trecho com baixa capacidade de suporte de carga. A flecha foi medida pelo método fotográfico para cada número de passadas, nas condições com e sem reforço, e submetido à análise de variância, pelo teste de F, a 5% de probabilidade, e quando houve diferença significativa entre os tratamentos, suas médias foram comparadas pelo teste de Tukey. Posteriormente, realizou-se o cálculo da razão de benefício de tráfego fornecida pela inclusão do reforço. O geossintético não tecido, quando inserido no interior do solo, contribui de modo significativo para a redução das flechas, principalmente nos solos do trecho das estradas I e III. O geossintético tecido contribui para a redução das flechas, principalmente nos solos do trecho da estrada III. A geogrelha não contribui para a redução das flechas. A razão de benefício de tráfego para os reforços utilizados foram superiores a um, com valores médios de 1,28 para o trecho da estrada I, reforçado com geossintético não tecido, 1,54 para o trecho da estrada II, reforçado com geossintético tecido e de 2,7 para o trecho da estrada III, reforçado com geossintético tecido.The objective of this study was to evaluate the performance of unpaved roads built on soft soils reinforced with different geosynthetic materials. We selected three sections of unpaved roads with low load-bearing capacity. Vertical displacement (rut depth) was visually measured (photographs) for each number of passes on soils with and without reinforcement. The data underwent variance analysis by the F-test at 5% probability; when significant, means were compared by the Tukey’s test. Subsequently, we calculated traffic benefit ratio (TBR) or improvement factor due to the use of each reinforcement material. Non-woven geosynthetic materials reduced significantly the rut depths, mainly within the road sections I and III; by contrast, geosynthetic woven materials contributed in road section III. Moreover, geogrid use had no contribution to rut depth reductions. The TBR by using the reinforcements studied here showed values higher than one, with averages of 1.28 for road section I reinforced with geosynthetic nonwoven material, 1.54 for road section II reinforced with geosynthetic woven material, and 2.7 for road section III reinforced with geosynthetic woven

    Fast Evolutionary Adaptation for Monte Carlo Tree Search

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    This paper describes a new adaptive Monte Carlo Tree Search (MCTS) algorithm that uses evolution to rapidly optimise its performance. An evolutionary algorithm is used as a source of control parameters to modify the behaviour of each iteration (i.e. each simulation or roll-out) of the MCTS algorithm; in this paper we largely restrict this to modifying the behaviour of the random default policy, though it can also be applied to modify the tree policy

    Theoretical studies of Mefenamic Acid Polymorphs: Solid-state 13C carbon-NMR and vibrational (IR and Raman) Spectroscopies.

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    The two polymorphs of mefenamic acid (MEF) or 2-[(2,3-(dimethyphenyl)amino] benzoic acid polymorphs (known as I and II forms) were studies in the framkework of density functional theory (DFT). The DFT calculations were performed using the Gaussian03 package and these results were compared with experimental data of solid-state 13C Nuclear Magnetic Resonance (NMR), vibrational Raman and infrared spectroscopies.CAPESCNPqFAPES

    Fusarium wilt incidence and common bean yield according to the preceding crop and the soil tillage system

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    The objective of this work was to evaluate the effects of preceding crops and tillage systems on the incidence of Fusarium wilt (Fusarium oxysporum f. sp. phaseoli) and common bean (Phaseolus vulgaris) yield. The cultivar BRS Valente was cultivated under center‑pivot irrigation in the winter seasons of 2003, 2004 and 2005, after several preceding crops established in the summer seasons. Preceding crops included the legumes Cajanus cajan (pigeon pea), Stylosanthes guianensis, and Crotalaria spectabilis; the grasses Pennisetum glaucum (millet), Sorghum bicolor (forage sorghum), Panicum maximum, and Urochloa brizantha; and a consortium of maize (Zea mays) and U. brizantha (Santa Fé system). Experiments followed a strip‑plot design, with four replicates. Fusarium wilt incidence was higher in the no‑tillage system. Higher disease incidences corresponded to lower bean yields in 2003 and 2004. Previous summer cropping with U. brizantha, U. brizantha + maize consortium, and millet showed the lowest disease incidence. Therefore, the choice of preceding crops must be taken into account for managing Fusarium wilt on irrigated common bean crops in the Brazilian Cerrado

    Sociodemographic, clinical and laboratory factors on admission associated with COVID19 mortality in hospitalized patients: A retrospective observational study

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    Background To identify and quantify associations between baseline characteristics on hospital admission and mortality in patients with COVID-19 at a tertiary hospital in Spain. Methods and findings This retrospective case series included 238 patients hospitalized for COVID-19 at Hospital Universitario Clı´nico San Cecilio (Granada, Spain) who were discharged or who died. Electronic medical records were reviewed to obtain information on sex, age, personal antecedents, clinical features, findings on physical examination, and laboratory results for each patient. Associations between mortality and baseline characteristics were estimated as hazard ratios (HR) calculated with Cox regression models. Series mortality was 25.6%. Among patients with dependence for basic activities of daily living, 78.7% died, and among patients residing in retirement homes, 80.8% died. The variables most clearly associated with a greater hazard of death were age (3% HR increase per 1-year increase in age; 95%CI 1–6), diabetes mellitus (HR 2.42, 95%CI 1.43–4.09), SatO2/ FiO2 ratio (43% HR reduction per 1-point increase; 95%CI 23–57), SOFA score (19% HR increase per 1-point increase, 95%CI 5–34) and CURB-65 score (76% HR increase per 1- point increase, 95%CI 23–143). Conclusions The patients residing in retirement homes showed great vulnerability. The main baseline factors that were independently associated with mortality in patients hospitalized for COVID-19 were older age, diabetes mellitus, low SatO2/FiO2 ratio, and high SOFA and CURB-65 scores.Fondos Estructurales de la Union Europea (FEDER)Unit of Excellence on Exercise and Health (UCEES), University of Granad

    Children’s rights and digital technologies

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    Digital technologies have reshaped children’s lives, resulting in new opportunities for and risks to their well-being and rights. This chapter investigates the impact of digital technologies on children’s rights through the lens of the United Nations Convention on the Rights of the Child. Up until now, not all rights have received the same level of attention in the digital context. Legal and policy discourse in the area of children and digital media predominantly focuses on ‘protection’ rights, albeit with a growing awareness of the tension between ‘protection’ and ‘participation’ rights. ‘Provision’ rights are not often emphasised, other than in the important domain of education. However, all children’s rights should be supported, valued and developed in both online and offline spheres of engagement. Governments, parents, educators, industry, civil society and children’s rights commissioners or ombudspersons should all take up their responsibility to enhance children’s rights in relation to digital technologies, while actively listening and taking account of children’s views when developing laws, policies, programmes and other measures in this field

    A biclustering algorithm based on a Bicluster Enumeration Tree: application to DNA microarray data

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    <p>Abstract</p> <p>Background</p> <p>In a number of domains, like in DNA microarray data analysis, we need to cluster simultaneously rows (genes) and columns (conditions) of a data matrix to identify groups of rows coherent with groups of columns. This kind of clustering is called <it>biclustering</it>. Biclustering algorithms are extensively used in DNA microarray data analysis. More effective biclustering algorithms are highly desirable and needed.</p> <p>Methods</p> <p>We introduce <it>BiMine</it>, a new enumeration algorithm for biclustering of DNA microarray data. The proposed algorithm is based on three original features. First, <it>BiMine </it>relies on a new evaluation function called <it>Average Spearman's rho </it>(ASR). Second, <it>BiMine </it>uses a new tree structure, called <it>Bicluster Enumeration Tree </it>(BET), to represent the different biclusters discovered during the enumeration process. Third, to avoid the combinatorial explosion of the search tree, <it>BiMine </it>introduces a parametric rule that allows the enumeration process to cut tree branches that cannot lead to good biclusters.</p> <p>Results</p> <p>The performance of the proposed algorithm is assessed using both synthetic and real DNA microarray data. The experimental results show that <it>BiMine </it>competes well with several other biclustering methods. Moreover, we test the biological significance using a gene annotation web-tool to show that our proposed method is able to produce biologically relevant biclusters. The software is available upon request from the authors to academic users.</p

    Biclustering via optimal re-ordering of data matrices in systems biology: rigorous methods and comparative studies

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    <p>Abstract</p> <p>Background</p> <p>The analysis of large-scale data sets via clustering techniques is utilized in a number of applications. Biclustering in particular has emerged as an important problem in the analysis of gene expression data since genes may only jointly respond over a subset of conditions. Biclustering algorithms also have important applications in sample classification where, for instance, tissue samples can be classified as cancerous or normal. Many of the methods for biclustering, and clustering algorithms in general, utilize simplified models or heuristic strategies for identifying the "best" grouping of elements according to some metric and cluster definition and thus result in suboptimal clusters.</p> <p>Results</p> <p>In this article, we present a rigorous approach to biclustering, OREO, which is based on the Optimal RE-Ordering of the rows and columns of a data matrix so as to globally minimize the dissimilarity metric. The physical permutations of the rows and columns of the data matrix can be modeled as either a network flow problem or a traveling salesman problem. Cluster boundaries in one dimension are used to partition and re-order the other dimensions of the corresponding submatrices to generate biclusters. The performance of OREO is tested on (a) metabolite concentration data, (b) an image reconstruction matrix, (c) synthetic data with implanted biclusters, and gene expression data for (d) colon cancer data, (e) breast cancer data, as well as (f) yeast segregant data to validate the ability of the proposed method and compare it to existing biclustering and clustering methods.</p> <p>Conclusion</p> <p>We demonstrate that this rigorous global optimization method for biclustering produces clusters with more insightful groupings of similar entities, such as genes or metabolites sharing common functions, than other clustering and biclustering algorithms and can reconstruct underlying fundamental patterns in the data for several distinct sets of data matrices arising in important biological applications.</p
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