577 research outputs found

    Infusing Problem-Based Learning (PBL) Into Science Methods Courses Across Virginia

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    This article outlines the results of a collaborative study of the effects of infusing problem-based learning (PBL) into K-12 science methods courses across four universities in Virginia. Changes in pre-service teachers\u27 attitudes surrounding science teaching were measured before and after completing a science methods course in which they experienced PBL first-hand as participants, and then practiced designing their own PBL units for use in their future classrooms. The results indicate that exposure to PBL enhances pre-service teachers\u27 knowledge of inquiry methods and self-efficacy in teaching science

    Evaluation of real-time data obtained from gravimetric preparation of antineoplastic agents shows medication errors with possible critical therapeutic impact:Results of a large-scale, multicentre, multinational, retrospective study

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    What is known and objectiveMedication errors are a significant cause of morbidity and mortality especially with antineoplastic drugs, owing to their narrow therapeutic index. Gravimetric workflow software systems have the potential to reduce volumetric errors during intravenous antineoplastic drug preparation which may occur when verification is reliant on visual inspection. Our aim was to detect medication errors with possible critical therapeutic impact as determined by the rate of prevented medication errors in chemotherapy compounding after implementation of gravimetric measurement. DesignA large-scale, retrospective analysis of data was carried out, related to medication errors identified during preparation of antineoplastic drugs in 10 pharmacy services (centres) in five European countries following the introduction of an intravenous workflow software gravimetric system. Errors were defined as errors in dose volumes outside tolerance levels, identified during weighing stages of preparation of chemotherapy solutions which would not otherwise have been detected by conventional visual inspection. Key resultsThe gravimetric system detected that 7.89% of the 759060 doses of antineoplastic drugs prepared at participating centres between July 2011 and October 2015 had error levels outside the accepted tolerance range set by individual centres, and prevented these doses from reaching patients. The proportion of antineoplastic preparations with deviations >10% ranged from 0.49% to 5.04% across sites, with a mean of 2.25%. The proportion of preparations with deviations >20% ranged from 0.21% to 1.27% across sites, with a mean of 0.71%. There was considerable variation in error levels for different antineoplastic agents. What is new and conclusionIntroduction of a gravimetric preparation system for antineoplastic agents detected and prevented dosing errors which would not have been recognized with traditional methods and could have resulted in toxicity or suboptimal therapeutic outcomes for patients undergoing anticancer treatment

    Mosaic expression of Atrx in the mouse central nervous system causes memory deficits

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    The rapid modulation of chromatin organization is thought to play a crucial role in cognitive processes such as memory consolidation. This is supported in part by the dysregulation of many chromatin-remodelling proteins in neurodevelopmental and psychiatric disorders. A key example is ATRX, an X-linked gene commonly mutated in individuals with syndromic and nonsyndromic intellectual disability. The consequences of Atrx inactivation for learning and memory have been difficult to evaluate because of the early lethality of hemizygous-null animals. In this study, we evaluated the outcome of brain-specific Atrx deletion in heterozygous female mice. These mice exhibit a mosaic pattern of ATRX protein expression in the central nervous system attributable to the location of the gene on the X chromosome. Although the hemizygous male mice die soon after birth, heterozygous females survive to adulthood. Body growth is stunted in these animals, and they have low circulating concentrations of insulin growth factor 1. In addition, they are impaired in spatial, contextual fear and novel object recognition memory. Our findings demonstrate that mosaic loss of ATRX expression in the central nervous system leads to endocrine defects and decreased body size and has a negative impact on learning and memory

    Genomes of diverse isolates of the marine cyanobacterium Prochlorococcus

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    The marine cyanobacterium Prochlorococcus is the numerically dominant photosynthetic organism in the oligotrophic oceans, and a model system in marine microbial ecology. Here we report 27 new whole genome sequences (2 complete and closed; 25 of draft quality) of cultured isolates, representing five major phylogenetic clades of Prochlorococcus. The sequenced strains were isolated from diverse regions of the oceans, facilitating studies of the drivers of microbial diversity—both in the lab and in the field. To improve the utility of these genomes for comparative genomics, we also define pre-computed clusters of orthologous groups of proteins (COGs), indicating how genes are distributed among these and other publicly available Prochlorococcus genomes. These data represent a significant expansion of Prochlorococcus reference genomes that are useful for numerous applications in microbial ecology, evolution and oceanography.Gordon and Betty Moore Foundation (Grant GBMR #495.01)National Science Foundation (U.S.) (Grant OCE-1153588)National Science Foundation (U.S.) (Grant OCE-0425602)National Science Foundation (U.S.) (Grant DBI-0424599)Center for Microbial Oceanography: Research and Educatio

    Physiology and evolution of nitrate acquisition in Prochlorococcus

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    Prochlorococcus is the numerically dominant phototroph in the oligotrophic subtropical ocean and carries out a significant fraction of marine primary productivity. Although field studies have provided evidence for nitrate uptake by Prochlorococcus, little is known about this trait because axenic cultures capable of growth on nitrate have not been available. Additionally, all previously sequenced genomes lacked the genes necessary for nitrate assimilation. Here we introduce three Prochlorococcus strains capable of growth on nitrate and analyze their physiology and genome architecture. We show that the growth of high-light (HL) adapted strains on nitrate is ~17% slower than their growth on ammonium. By analyzing 41 Prochlorococcus genomes, we find that genes for nitrate assimilation have been gained multiple times during the evolution of this group, and can be found in at least three lineages. In low-light adapted strains, nitrate assimilation genes are located in the same genomic context as in marine Synechococcus. These genes are located elsewhere in HL adapted strains and may often exist as a stable genetic acquisition as suggested by the striking degree of similarity in the order, phylogeny and location of these genes in one HL adapted strain and a consensus assembly of environmental Prochlorococcus metagenome sequences. In another HL adapted strain, nitrate utilization genes may have been independently acquired as indicated by adjacent phage mobility elements; these genes are also duplicated with each copy detected in separate genomic islands. These results provide direct evidence for nitrate utilization by Prochlorococcus and illuminate the complex evolutionary history of this trait.Gordon and Betty Moore Foundation (Grant GBMF495)National Science Foundation (U.S.) (Grant OCE-1153588)National Science Foundation (U.S.) (Grant DBI-0424599

    Dietary calcium and vitamin D intakes in childhood and throughout adulthood and mammographic density in a British birth cohort

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    We examined the role of dietary calcium and vitamin D intakes in childhood and throughout adulthood in relation to mammographic density using data from a nationally representative cohort of 1161 women followed up since their birth in 1946. Dietary intakes at the age of 4 years were determined by 24-h recalls and at the ages of 36, 43 and 53 years by 5-day food records. After adjusting for known risk factors and confounders, no evidence of a relationship between dietary calcium or vitamin D intakes and mammographic density approximately at the age of 50 years was found, except for a cross-sectional relationship between dietary calcium intake at the age of 53 years and breast density in women who were post-menopausal at the time of mammography, with those in the top fifth of the distribution of calcium intake having a 0.53 s.d. lower percent breast density than those in the lowest fifth (P-value <0.01 for linear trend)

    Promoting responsibility, shaping behaviour: housing management, mixed communities and the construction of citizenship

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    This article examines housing policies aimed at establishing mixed income communities. Based on stakeholder interviews and case study analysis in England and Scotland, the article pays particular attention to the impact of interventions in housing management. The first part of the article considers the policy context for mixed communities and considers the conceptual basis underlying contemporary housing management through discourses of culture and social control. The second part considers how this agenda has resulted in the adoption of intensive management strategies within mixed communities; illustrated in the development of allocation policies, initiatives designed to tackle anti-social behaviour and proposals to develop sustainable communities. The main argument is given that the concept of mixed communities is based on the premise of social housing failure, citizenship has been defined largely in response to private sector interests. This approach to management has been a contributory factor in the construction of social housing as a form of second-class citizenship
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