257 research outputs found
Can marks and report cards be abolished in the Elementary schools?
Thesis (M.A.)--Boston University
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Monte Carlo Electron Trajectory Calculations of Electron Interactions in Samples with Special Geometries
Implementing a Monte Carlo simulation for application to electron sample interactions requires use of accurate treatments of elastic and inelastic scattering. In formulating a Monte Carlo simulation, careful testing must be carried out to ensure that the calculation yields sensible and useful results. A suitable testing procedure includes calculation of (1) electron backscatter coefficients as a function of atomic number, including any necessary adjustment of scattering parameters; (2) backscatter coefficients as a function of specimen tilt; (3) backscatter and transmission coefficients for thin foils; (4) backscattered electron energy distributions; (5) electron spatial distributions; and (6) x-rays, including x-ray depth distributions, and relative and absolute yields.
Adapting a Monte Carlo simulation to a particular problem involving special sample geometry requires careful consideration of the interaction of the electron with the target. When the electron trajectory crosses a boundary, the segments of the trajectory in each phase must be calculated in a logical, stepwise fashion, allowing for modification of the step lengths due to variable scattering power in phases of different composition. The particular example of a planar boundary between phases of different composition is considered
Alcohol screening and brief intervention for adolescents: The how, what and where of reducing alcohol consumption and related harm among young people
Aim: The aim of the study was to explore the evidence base on alcohol screening and brief intervention for adolescents to determine age appropriate screening tools, effective brief interventions and appropriate locations to undertake these activities. Methods: A review of existing reviews (2003-2013) and a systematic review of recent research not included in earlier reviews. Results: The CRAFFT and AUDIT tools are recommended for identification of 'at risk' adolescents. Motivational interventions delivered over one or more sessions and based in health care or educational settings are effective at reducing levels of consumption and alcohol-related harm. Conclusion: Further research to develop age appropriate screening tools needs to be undertaken. Screening and brief intervention activity should be undertaken in settings where young people are likely to present; further assessment at such venues as paediatric emergency departments, sexual health clinics and youth offending teams should be evaluated. The use of electronic (web/smart-phone based) screening and intervention shows promise and should also be the focus of future research. © The Author 2013. Published by Oxford University Press on behalf of the Medical Council on Alcohol
Mutational Analysis in Pediatric Thyroid Cancer and Correlations with Age, Ethnicity, and Clinical Presentation.
BackgroundWell-differentiated thyroid cancer (WDTC) incidence in pediatrics is rising, most being papillary thyroid carcinoma (PTC). The objective of the study was to assess the prevalence of different mutations in pediatric WDTC and correlate the genotype with the clinical phenotype.MethodsThis is a single-center retrospective study. Thyroid tissue blocks from 42 consecutive pediatric WDTC patients who underwent thyroidectomy between 2001 and 2013 were analyzed at Quest Diagnostics for BRAF(V600E), RAS mutations (N,K,H), and RET/PTC and PAX8/PPARγ rearrangements, using validated molecular methods. Thyroid carcinomas included PTC, follicular thyroid carcinoma (FTC), and follicular variant of PTC (FVPTC).ResultsThirty-nine samples (29 females) were genotyped. The mean age at diagnosis was 14.7 years (range 7.9-18.4 years), and most were Hispanic (56.4%) or Caucasian (35.9%). The mean follow-up period was 2.9 years. Mutations were noted in 21/39 (53.8%), with both BRAF(V600E) (n = 9), and RET/PTC (n = 6) detected only in PTC. Mutations were detected in 2/5 FTC (PAX8/PPARγ and NRAS) and 3/6 FVPTC cases (PAX8/PPARγ). Of 28 PTC patients, 57.1% had mutations: 32.1% with BRAF(V600E), 21.4% with RET/PTC, and 3.6% with NRAS. Of patients with BRAF(V600E), 77.8% were Hispanic and 88.9% were >15 years, while all RET/PTC-positive patients were ≤15 years (p = 0.003). Tumor size, lymph node involvement, and distant metastasis at diagnosis (or soon after (131)I ablation) did not vary significantly based on the mutation.ConclusionsBRAF(V600E) was the most common mutation, especially in older and Hispanic adolescents. A larger, ethnically diverse pediatric cohort followed long term will enable the genotypic variability, clinical presentation, and response to therapy to be better assessed
Exploring and developing a longitudinal cohort study of babies born within Middlesbrough and Redcar and Cleveland:The Lockdown Babies Study: SUMMARY
Exploring and developing a longitudinal cohort study of babies born within Middlesbrough and Redcar and Cleveland:The Lockdown Babies Study: Executive summary
Exploring and developing a longitudinal cohort study of babies born within Middlesbrough and Redcar and Cleveland:The Lockdown Babies Study: Executive summary
The overarching aim of the research project is to utilise a co-production approach to ascertain the impact of lockdown on parents giving birth during the pandemic, and any perceived impact on their babies, in Middlesbrough and Redcar & Cleveland
Exploring and developing a longitudinal cohort study of babies born within Middlesbrough and Redcar and Cleveland:The Lockdown Babies Study: SUMMARY
Development and Application of a Functional Human Esophageal Mucosa Explant Platform to Eosinophilic Esophagitis.
There is an increasing prevalence of esophageal diseases but intact human tissue platforms to study esophageal function, disease mechanisms, and the interactions between cell types in situ are lacking. To address this, we utilized full thickness human donor esophagi to create and validate the ex vivo function of mucosa and smooth muscle (n = 25). Explanted tissue was tested for contractile responses to carbachol and histamine. We then treated ex vivo human esophageal mucosa with a cytokine cocktail to closely mimic the Th2 and inflammatory milieu of eosinophilic esophagitis (EoE) and assessed alterations in smooth muscle and extracellular matrix function and stiffening. We found that full thickness human esophagus as well as the individual layers of circular and longitudinal muscularis propria developed tension in response to carbachol ex vivo and that mucosa demonstrated squamous cell differentiation. Treatment of mucosa with Th2 and fibrotic cytokines recapitulated the majority of the clinical Eosinophilic Esophagitis Diagnostic Profile (EDP) on fluidic transcriptional microarray. Transforming growth factor-beta-1 (TGFβ1) increased gene expression of fibronectin, smooth muscle actin, and phospholamban (p < 0.001). The EoE cocktail also increased stiffness and decreased mucosal compliance, akin to the functional alterations in EoE (p = 0.001). This work establishes a new, transcriptionally intact and physiologically functional human platform to model esophageal tissue responses in EoE
Association of Ataxia Telangiectasia Mutated (ATM) Gene Mutation/Deletion with Rhabdomyosarcoma – retraction
<p>Abstract</p> <p>Background</p> <p>Rhabdomyosarcoma is a common malignancy in children. There are two major types of rhabdomyosarcomas, the embryonal and the alveolar, differing in cytogenetic and morphologic features. The alveolar type of rhabdomyosarcoma is frequently associated with chromosome translocation t(2, 13) and poor clinical prognosis. Pathogenesis of rhabdomyosarcoma remains obscure, and especially it occurs in the location where skeletal muscle is absent. We report here that there is a high frequency of association of rhabdomyosarcoma with ataxia telangiectasia mutated (ATM) gene mutation/deletion.</p> <p>Result</p> <p>Totally 17 cases of rhabdomyosarcoma specimens were studied by immunohistochemical or immunofluorescent staining with ATM antibody and revealed that 7 of the 17 cases were negative for ATM expression (41%). Further analyses of rhabdomyosarcoma cell lines with RT-PCR revealed that in Rh30 cells, an alveolar rhabdomyosarcoma cell line, there are three separate deletions/mutations of the ATM mRNA. Western blotting analysis of the Rh30 cellular extract with anti-ATM antibody showed that there is an aberrant form of ATM protein within the Rh30 cells that are smaller than normal control.</p> <p>Conclusion</p> <p>These results suggest a link of ATM gene deletion/mutation with rhabdomyosarcoma, and since ATM kinase is a crucial regulatory protein in DNA damage repair signaling pathway, and ATM deletion/mutation may contribute to pathogenesis of rhabdomyosarcoma.</p
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