359 research outputs found

    Conference Program

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    Mathematics and Science in Primary Teacher Education: The Design of a Project to Encourage Review at the Institutional Level

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    Over the past two decades evaluation has been one of the growth industries in education. A major impetus for this development, particularly in the united States of America, has been the mandating of evaluations for major policy initiatives at federal and state levels (House, 1981). One result of such legislation has been that academics and private organisations have been engaged, often on long term assignments, to pass judgements on the worth of interventions designed to improve the quality of education made available in educational systems. Features of this approach to evaluation have been that they are large scale well funded, and conducted by experts who have no stake in the programs. Invariably such evaluations have policy makers and politicians as their major audiences, and their major concern is with accountability, making judgements regarding the worth of programs which reflect given policies

    Analysing and modelling train driver performance

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    Arguments for the importance of contextual factors in understanding human performance have been made extremely persuasive in the context of the process control industries. This paper puts these arguments into the context of the train driving task, drawing on an extensive analysis of driver performance with the Automatic Warning System (AWS). The paper summarises a number of constructs from applied psychological research which are thought to be important in understanding train driver performance. A “Situational Model” is offered as a framework for investigating driver performance. The model emphasises the importance of understanding the state of driver cognition at a specific time (“Now”) in a specific situation and a specific context

    The phase I multicenter trial (STAPLE-1) of the Aptus Endovascular Repair System: Results at 6 months and 1 year

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    Objective: This phase I IDE study (STAPLE-1) evaluated the primary endpoints of safety (major device-related adverse events at 30 days) and feasibility (successful deployment of all endograft components) of the Aptus Endovascular abdominal aortic aneurysm (AAA) Repair System (Aptus Endosystems, Inc, Sunnyvale, Calif) to treat AAAs. Methods: A prospective, single arm Federal Drug Administration (FDA) Phase I IDE study was performed. The Aptus endograft is a three-piece modular device with a flexible unsupported main body and two fully supported limbs in a 5.3 mmouter diameter (OD) (16F) delivery system for all iliac limbs and two of three main body sizes. The largest main body (29 mm diameter) is in a 6 mm (18 F OD) delivery system. EndoStaples measuring 4 mm (length) by 3 mm (diameter) designed to provide transmural graft fixation to the adventitia are applied independent of the endograft delivery system. Inclusion criteria included a proximal aortic neck length of 12 mm and iliac landing zone of 10 mm. Secondary endpoints included freedom from endoleaks, rupture, migration, and device integrity. Results: Twenty-one (21) patients were enrolled at five centers. All patients received the Aptus Endograft and EndoStaples. Ninety-six EndoStaples (range, 2-10; median, 4) were implanted. All patients (n = 21) completed 1-month and 6-month follow-up evaluation and 14 completed 1-year follow-up. Two proximal cuffs and one limb extension were used as adjunctive endograft components at implantation. Three secondary interventions were performed in 2 patients for limb thrombosis. There were no EndoStaple-related adverse events, device integrity failures, migrations, or conversions. Conclusion: These results of the STAPLE-1 trial document the acute safety and feasibility of the Aptus Endograft and EndoStaples. Early follow-up demonstrates excellent 6-month and 1-year results. A pivotal phase II trial is underway at 25 US centers. ( J Vasc Surg 2009;49:851-8.

    Dataset of RNA-Seq transcriptome of the fetal liver at day 83 of gestation associated with periconceptual maternal nutrition in beef heifers

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    Herein, we present a dataset based on the RNA-Seq analysis of liver tissue from bovine female fetuses at day 83 of gestation. The findings were reported in the main article, “Periconceptual maternal nutrition affects fetal liver programming of energy- and lipid-related genes”[1] . These data were generated to investigate the effects of periconceptual maternal vitamin and mineral supplementation and rates of body weight gain on the transcript abundance of genes associated with fetal hepatic metabolism and function. To this end, crossbred Angus beef heifers ( n = 35) were randomly assigned to 1 of 4 treatments in a 2 × 2 factorial design. The main effects tested were vitamin and mineral supplementation (VTM or NoVTM –at least 71 days pre-breeding to day 83 of gestation) and rate of weight gain (low (LG –0.28 kg/d) or moderate (MG – 0.79 kg/d) – from breeding to day 83). The fetal liver was collected on day 83 ± 0.27 of gestation. After total RNA isolation and quality control, strand-specific RNA libraries were prepared and sequenced on the Illumina® NovaSeq 60 0 0 platform to generate paired-end 150-bp reads. After read mapping and counting, differential expression analysis was performed with edgeR. We identified 591 unique differentially expressed genes across all six vitamin- gain contrasts (FDR ≤ 0.1). To our knowledge, this is the first dataset investigating the fetal liver transcriptome in response to periconceptual maternal vitamin and mineral supplementation and/or the rate of weight gain. The data described in this article provides genes and molecular pathways differentially programming liver development and function

    Maternal Vitamin and Mineral Supplementation and Rate of Maternal Weight Gain Affects Placental Expression of Energy Metabolism and Transport-Related Genes

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    Maternal nutrients are essential for proper fetal and placental development and function. However, the effects of vitamin and mineral supplementation under two rates of maternal weight gain on placental genome-wide gene expression have not been investigated so far. Furthermore, biological processes and pathways in the placenta that act in response to early maternal nutrition are yet to be elucidated. Herein, we examined the impact of maternal vitamin and mineral supplementation (from pre-breeding to day 83 post-breeding) and two rates of gain during the first 83 days of pregnancy on the gene expression of placental caruncles (CAR; maternal placenta) and cotyledons (COT; fetal placenta) of crossbred Angus beef heifers. We identified 267 unique differentially expressed genes (DEG). Among the DEGs from CAR, we identified ACAT2, SREBF2, and HMGCCS1 that underlie the cholesterol biosynthesis pathway. Furthermore, the transcription factors PAX2 and PAX8 were over-represented in biological processes related to kidney organogenesis. The DEGs from COT included SLC2A1, SLC2A3, SLC27A4, and INSIG1. Our over-representation analysis retrieved biological processes related to nutrient transport and ion homeostasis, whereas the pathways included insulin secretion, PPAR signaling, and biosynthesis of amino acids. Vitamin and mineral supplementation and rate of gain were associated with changes in gene expression, biological processes, and KEGG pathways in beef cattle placental tissues

    Untangling the placentome gene network of beef heifers in early gestation

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    The cotyledon and caruncle tissues provide a functional bridge between the fetus and the dam. However, the relationship between these tissues and the transcriptomic profile that underlies the tissue functions remains elusive. Herein we investigate the expression profile of cotyledon and caruncle from nulliparous beef heifers carrying female fetuses at day 83 of pregnancy to identify changes occurring across tissues that contribute to placental function and their tissue-specific roles. We identified 2654 differentially expressed genes [padj ≤ 0.05, abs(log2FC) ≥ 1], including nutrient transporters and paternally imprinted genes. We found key regulators of tissue function and differentiation, including FOXO4, GATA2, GATA3, and HAND1, rewired between the tissues. Finally, we shed light on the over-represented pathways related to immune tolerance, tissue differentiation and remodeling. Our findings highlighted the intricate and coordinated cross-talk between fetal-maternal tissues. They provided evidence of a fine-tuned gene regulatory network underlying pregnancy and tissue-specific function in the bovine placenta

    Vitamin and Mineral Supplementation and Rate of Gain in Beef Heifers I: Effects on Dam Hormonal and Metabolic Status, Fetal Tissue and Organ Mass, and Concentration of Glucose and Fructose in Fetal Fluids at d 83 of Gestation

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    Thirty-five crossbred Angus heifers (initial BW = 359.5 ± 7.1 kg) were randomly assigned to a 2 × 2 factorial design to evaluate effects of vitamin and mineral supplementation [VMSUP; supplemented (VTM) vs. unsupplemented (NoVTM)] and different rates of gain [GAIN; low gain (LG), 0.28 kg/d, vs. moderate gain (MG), 0.79 kg/d] during the first 83 d of gestation on dam hormone and metabolic status, fetal tissue and organ mass, and concentration of glucose and fructose in fetal fluids. The VMSUP was initiated 71 to 148 d before artificial insemination (AI), allowing time for mineral status of heifers to be altered in advance of breeding. At AI heifers were assigned their GAIN treatment. Heifers received treatments until the time of ovariohysterectomy (d 83 ± 0.27 after AI). Throughout the experiment, serum samples were collected and analyzed for non-esterified fatty acids (NEFA), progesterone (P4), insulin, and insulin-like growth factor 1 (IGF-1). At ovariohysterectomy, gravid reproductive tracts were collected, measurements were taken, samples of allantoic (ALF) and amniotic (AMF) fluids were collected, and fetuses were dissected. By design, MG had greater ADG compared to LG (0.85 vs. 0.34 ± 0.04 kg/d, respectively; p \u3c 0.01). Concentrations of NEFA were greater for LG than MG (p = 0.04) and were affected by a VMSUP × day interaction (p \u3c 0.01), with greater concentrations for NoVTM on d 83. Insulin was greater for NoVTM than VTM (p = 0.01). A GAIN × day interaction (p \u3c 0.01) was observed for IGF-1, with greater concentrations for MG on d 83. At d 83, P4 concentrations were greater for MG than LG (GAIN × day, p \u3c 0.01), and MG had greater (p \u3c 0.01) corpus luteum weights versus LG. Even though fetal BW was not affected (p ≥ 0.27), MG fetuses had heavier (p = 0.01) femurs than LG, and VTM fetuses had heavier (p = 0.05) livers than those from NoVTM. Additionally, fetal liver as a percentage of BW was greater in fetuses from VTM (P = 0.05; 3.96 ± 0.06% BW) than NoVTM (3.79 ± 0.06% BW), and from LG (p = 0.04; 3.96 ± 0.06% BW) than MG (3.78 ± 0.06% BW). A VMSUP × GAIN interaction was observed for fetal small intestinal weight (p = 0.03), with VTM-MG being heavier than VTM-LG. Therefore, replacement heifer nutrition during early gestation can alter the development of organs that are relevant for future offspring performance. These data imply that compensatory mechanisms are in place in the developing conceptus that can alter the growth rate of key metabolic organs possibly in an attempt to increase or decrease energy utilization
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