668 research outputs found

    Teachers’ receptive and productive vocabulary sizes in English-medium instruction

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    Despite the growing popularity of English-medium instruction (EMI), the conditions for and consequences of teaching and learning academic content through English are poorly understood. The ability of teachers in the EMI environment (i.e. disciplinary or ‘content’ teachers) to engage students in English is central in this regard since intelligible interaction between the teacher and the students is a precondition for learning when the medium of instruction is English. Across EMI contexts, concerns have been raised about teachers’ level of English proficiency (their ability to speak, write, read and listen in English), but research measuring their English proficiency attainments is lacking. This paper focuses on a key dimension of teachers’ English proficiency: vocabulary knowledge. Teachers (n = 130) took tests of receptive and productive knowledge of general and academic English vocabulary. The testing revealed significant proficiency variation in the cohorts tested, with some teachers exhibiting very low levels (<3000 words) of receptive and productive vocabulary knowledge. Implications for teaching in EMI are discussed

    The structure of human dermatan sulfate epimerase 1 emphasizes the importance of C5 epimerization of glucuronic acid in higher organisms

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    Dermatan sulfate epimerase 1 DS epi1, EC 5.1.3.19 catalyzes the conversion of D glucuronic acid to L iduronic acid on the polymer level, a key step in the biosynthesis of the glycosaminoglycan dermatan sulfate. Here, we present the first crystal structure of the catalytic domains of DS epi1, solved at 2.4 resolution, as well as a model of the full length luminal protein obtained by a combination of macromolecular crystallography and targeted cross linking mass spectrometry. Based on docking studies and molecular dynamics simulations of the protein structure and a chondroitin substrate, we suggest a novel mechanism of DS epi1, involving a His double Tyr motif. Our work uncovers detailed information about the domain architecture, active site, metal coordinating center and pattern of N glycosylation of the protein. Additionally, the structure of DS epi1 reveals a high structural similarity to proteins from several families of bacterial polysaccharide lyases. DS epi1 is of great importance in a range of diseases, and the structure provides a necessary starting point for design of active site inhibitor

    The Path to Preservation: Using Proteomics to Decipher the Fate of Diatom Proteins During Microbial Degradation

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    We drew upon recent advances in tandem mass spectrometry-based proteomic analyses in order to examine the proteins that remain after a diatom bloom enters the stationary phase, precipitates out of the photic zone, and is subjected to microbial degradation over a 23-d period within a controlled laboratory environment. Proteins were identified from tandem mass spectra searched against three different protein databases in order to track proteins from Thalassiosira pseudonana and any potential bacterial contributions. A rapid loss of diatom protein was observed over the incubation period; 75% of the proteins initially identified were not detected after 72 h of exposure to a microbial population. By the 23rd day, peptides identified with high confidence correlated with only four T. pseudonana proteins. Five factors may have influenced the preservation of diatom proteins: (1) protection within organelles or structures with multiple membranes, (2) the relative cellular abundance in the photosynthetic apparatus, (3) the number of transmembrane domains in the protein sequence, (4) the presence of glycan modification motifs, and (5) the capability of proteins or peptides to aggregate into supramolecules

    Serum Calcium and the Risk of Breast Cancer: Findings from the Swedish AMORIS Study and a Meta-Analysis of Prospective Studies

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    To investigate the association between serum calcium and risk of breast cancer using a large cohort and a systematic review with meta-analysis. From the Swedish Apolipoprotein Mortality Risk (AMORIS) Study we included 229,674 women who had baseline measurements of serum total calcium and albumin. Multivariable Cox regression was used to assess the association between total and albumin-corrected calcium and breast cancer risk. For the systematic review, an electronic search of MEDLINE and EMBASE databases was performed to identify other prospective cohorts assessing the relationship between serum calcium and breast cancer risk. We pooled the results of our AMORIS cohort with other eligible studies in a meta-analysis using a random effects model. I² test was used to assess heterogeneity. In the AMORIS study, 10,863 women were diagnosed with breast cancer (mean follow-up: 19 years). We found an inverse association between total serum calcium and breast cancer when comparing the fourth quartile to the first quartile (HR: 0.94, 95% CI: 0.88-0.99, p value for trend 0.04) and similar results using albumin-corrected calcium. In the systematic review, we identified another two prospective cohorts evaluating pre-diagnostic serum total calcium and breast cancer. Combining these studies and our findings in AMORIS in a meta-analysis showed a protective effect of serum calcium against breast cancer, with a summary RR of 0.80 (95% CI: 0.66-0.97). No substantial heterogeneity was observed. Our findings in AMORIS and the meta-analysis support an inverse association between serum calcium and breast cancer risk, which warrants mechanistic investigations

    Bias-voltage dependence of the magneto-resistance in ballistic vacuum tunneling: Theory and application to planar Co(0001) junctions

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    Motivated by first-principles results for jellium and by surface-barrier shapes that are typically used in electron spectroscopies, the bias voltage in ballistic vacuum tunneling is treated in a heuristic manner. The presented approach leads in particular to a parameterization of the tunnel-barrier shape, while retaining a first-principles description of the electrodes. The proposed tunnel barriers are applied to Co(0001) planar tunnel junctions. Besides discussing main aspects of the present scheme, we focus in particular on the absence of the zero-bias anomaly in vacuum tunneling.Comment: 19 pages with 8 figure

    Pathological complete response after neoadjuvant chemotherapy is an independent predictive factor irrespective of simplified breast cancer intrinsic subtypes: a landmark and two-step approach analyses from the EORTC 10994/BIG 1-00 phase III trial

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    The present analysis, carried out in the context of a randomized phase III trial, confirms superior outcomes for breast cancer patients for whom chemotherapy induces pathological complete response (pCR) after adjusting for other important prognostic factors. In contrast, when tumours do not achieve pCR, patients have a higher risk of relapse. This effect is observed in all intrinsic subtypes and justifies the current interest in post-neoadjuvant trial

    Gene expression profiling in primary breast cancer distinguishes patients developing local recurrence after breast-conservation surgery, with or without postoperative radiotherapy

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    Introduction Some patients with breast cancer develop local recurrence after breast-conservation surgery despite postoperative radiotherapy, whereas others remain free of local recurrence even in the absence of radiotherapy. As clinical parameters are insufficient for identifying these two groups of patients, we investigated whether gene expression profiling would add further information. Methods We performed gene expression analysis (oligonucleotide arrays, 26,824 reporters) on 143 patients with lymph node-negative disease and tumor-free margins. A support vector machine was employed to build classifiers using leave-one-out cross-validation. Results Within the estrogen receptor-positive (ER+) subgroup, the gene expression profile clearly distinguished patients with local recurrence after radiotherapy (n = 20) from those without local recurrence (n = 80 with or without radiotherapy). The receiver operating characteristic (ROC) area was 0.91, and 5,237 of 26,824 reporters had a P value of less than 0.001 (false discovery rate = 0.005). This gene expression profile provides substantially added value to conventional clinical markers (for example, age, histological grade, and tumor size) in predicting local recurrence despite radiotherapy. Within the ER- subgroup, a weaker, but still significant, signal was found (ROC area = 0.74). The ROC area for distinguishing patients who develop local recurrence from those who remain local recurrence-free in the absence of radiotherapy was 0.66 (combined ER+/ER-). Conclusion A highly distinct gene expression profile for patients developing local recurrence after breast-conservation surgery despite radiotherapy has been identified. If verified in further studies, this profile might be a most important tool in the decision making for surgery and adjuvant therapy
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