202 research outputs found

    The Shield and the Cloak: The Security of the Commons

    Get PDF

    Flying blind with badly behaving technology: a case study of integrating 1:1 computers in middle school

    Get PDF
    Doctor of EducationDepartment of Educational LeadershipKakali BhattacharyaDavid C. ThompsonInformation and communication technology is becoming more affordable and available to schools. In response to the emerging need to produce students with academic skills appropriate for 21st-century learners, many schools are investing large sums of money into this technology in an effort to create learning environments where students have a 1:1 ratio with access to tools such as laptops, tablets, or other types of portable devices. While there is evidence demonstrating that 1:1 student device adoptions can influence instruction and student learning, there is an ever-present, evolving need for scholarship concerning the experiences of teachers participating in such initiatives. The premise of this study is that teachers can provide valuable understanding concerning 1:1 computer adoptions, as they are one of the primary instruments in its success. The purpose of this study was to explore how two middle school teachers in a Midwestern city described the effects of ubiquitous computer access for students on their instructional practices and overall student learning as they participated in a district-wide 1:1 computer initiative. Participants for this qualitative case study were selected through purposeful- and criterion-based sampling. The participants were chosen from a pool of classroom teachers participating in the early phase of their district’s 1:1 initiative. Additionally, the participants’ eagerness to participate in the study as well as their comfort level with technology played a role in selection. Symbolic interactionism provided the lens through which to analyze the participants’ meaning making and the framework of TPACK afforded the substantive lens for discussing their experiences. Many of the individual aspects of the findings of this study are not new or particularly insightful by themselves and largely confirm existing findings in the scholarship. However, the significance of this study lies not in the corroboration of existing scholarship, but instead in illustration of the anatomy of change. In the end, this study investigating ICT integration wasn’t about technology at all. It was about the experience of transition. This study, with rich detail and context, shows the anatomy of transition for the two participants’ pedagogical practices and beliefs from the start of the process to the end. It provides insight into how things come to be and the way in which they come to be. It provides insight into how and why participants moved back and forth across the TPACK domains as they assimilated their fundamental beliefs with their lived experiences. The outcomes of this research suggest avenues for policy makers, administrators, teachers, and professional development organizers to increase the influence of 1:1 initiatives. It is necessary for all involved stakeholders to understand the importance of professional development in affecting technology-related change and to include training in any 1:1 adoption plan. It is equally important for teachers to understand that they will need to leverage formal and informal avenues of professional development to further their professional learning. Professional development organizers need to be cognizant of the needs of the staff and provide targeted, content-specific training in a timely manner. Last, district and building leaders should be aware of their organizational culture and the underlying goals for their 1:1 initiative and keep these in mind as they lead their staff through the change process

    Distribution, functional impact, and origin mechanisms of copy number variation in the barley genome

    Get PDF
    BACKGROUND There is growing evidence for the prevalence of copy number variation (CNV) and its role in phenotypic variation in many eukaryotic species. Here we use array comparative genomic hybridization to explore the extent of this type of structural variation in domesticated barley cultivars and wild barleys. RESULTS A collection of 14 barley genotypes including eight cultivars and six wild barleys were used for comparative genomic hybridization. CNV affects 14.9% of all the sequences that were assessed. Higher levels of CNV diversity are present in the wild accessions relative to cultivated barley. CNVs are enriched near the ends of all chromosomes except 4H, which exhibits the lowest frequency of CNVs. CNV affects 9.5% of the coding sequences represented on the array and the genes affected by CNV are enriched for sequences annotated as disease-resistance proteins and protein kinases. Sequence-based comparisons of CNV between cultivars Barke and Morex provided evidence that DNA repair mechanisms of double-strand breaks via single-stranded annealing and synthesis-dependent strand annealing play an important role in the origin of CNV in barley. CONCLUSIONS We present the first catalog of CNVs in a diploid Triticeae species, which opens the door for future genome diversity research in a tribe that comprises the economically important cereal species wheat, barley, and rye. Our findings constitute a valuable resource for the identification of CNV affecting genes of agronomic importance. We also identify potential mechanisms that can generate variation in copy number in plant genomes.This work was financially supported by the following grants: project GABI-BARLEX, German Federal Ministry of Education and Research (BMBF), #0314000 to MP, US, KFXM and NS; Triticeae Coordinated Agricultural Project, USDA-NIFA #2011-68002-30029 to GJM; and Agriculture and Food Research Initiative Plant Genome, Genetics and Breeding Program of USDA’s Cooperative State Research and Extension Service, #2009-65300- 05645 to GJM

    Clinical Study of Ursodeoxycholic Acid in Barrett's Esophagus Patients

    Get PDF
    Prior research strongly implicates gastric acid and bile acids, two major components of the gastroesophageal refluxate, in the development of Barrett’s esophagus (BE) and its pathogenesis. Ursodeoxycholic acid (UDCA), a hydrophilic bile acid, has been shown to protect esophageal cells against oxidative stress induced by cytotoxic bile acids. We conducted a pilot clinical study to evaluate the clinical activity of UDCA in patients with BE. Twenty-nine BE patients received UDCA treatment at a daily dose of 13–15 mg/kg/day for six months. The clinical activity of UDCA was assessed by evaluating changes in gastric bile acid composition and markers of oxidative DNA damage (8-hydroxydeoxyguanosine, 8OHdG), cell proliferation (Ki67), and apoptosis (cleaved caspase 3, CC3) in BE epithelium. The bile acid concentrations in gastric fluid were measured by liquid chromatography-mass spectrometry. At baseline, UDCA (sum of unchanged and glycine/taurine conjugates) accounted for 18.2% of total gastric bile acids. Post UDCA intervention, UDCA increased significantly to account for 93.39% of total gastric bile acids (p<0.0001). The expression of markers of oxidative DNA damage, cell proliferation, and apoptosis was assessed in the BE biopsies by immunohistochemistry. The selected tissue biomarkers were unchanged after 6 months of UDCA intervention. We conclude that high dose UDCA supplementation for six months resulted in favorable changes in gastric bile acid composition but did not modulate selected markers of oxidative DNA damage, cell proliferation, and apoptosis in the BE epithelium

    Maternal Exposure to Nitrogen Dioxide, Intake of Methyl Nutrients, and Congenital Heart Defects in Offspring

    Get PDF
    Nutrients that regulate methylation processes may modify susceptibility to the effects of air pollutants. Data from the National Birth Defects Prevention Study (United States, 1997-2006) were used to estimate associations between maternal exposure to nitrogen dioxide (NO2), dietary intake of methyl nutrients, and the odds of congenital heart defects in offspring. NO2 concentrations, a marker of traffic-related air pollution, averaged across postconception weeks 2-8, were assigned to 6,160 nondiabetic mothers of cases and controls using inverse distance-squared weighting of air monitors within 50 km of maternal residences. Intakes of choline, folate, methionine, and vitamins B6 and B12 were assessed using a food frequency questionnaire. Hierarchical regression models, which accounted for similarities across defects, were constructed, and relative excess risks due to interaction were calculated. Relative to women with the lowest NO2 exposure and high methionine intake, women with the highest NO2 exposure and lowest methionine intake had the greatest odds of offspring with a perimembranous ventricular septal defect (odds ratio = 3.23, 95% confidence interval: 1.74, 6.01; relative excess risk due to interaction = 2.15, 95% confidence interval: 0.39, 3.92). Considerable departure from additivity was not observed for other defects. These results provide modest evidence of interaction between nutrition and NO2 exposure during pregnancy
    • 

    corecore