504 research outputs found

    Providing Job Embedded Professional Learning for Mathematics Specialists

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    We know that if professional learning opportunities are to be meaningful and create long-lasting and systemic change, they must be ongoing and job-embedded. One of the most beneficial aspects of having mathematics specialists in schools is that they can provide job-embedded professional learning directly to teachers. Perhaps due to the strong impact mathematics specialists have on teaching and learning, we may overlook the need to provide professional learning to support the growth of mathematics specialists themselves. Just as we provide coaching to teachers to affect their professional growth, we must identify similar opportunities to affect the growth of mathematics specialists. This paper will identify the purposes of these opportunities to include supporting growth in content knowledge, pedagogical expertise, coaching skills, and professionalism and leadership. We recognize that sustained efforts must be undertaken to see significant growth in these areas. Through interviews with individuals from Virginia school divisions and professional organizations, we identify models that can be replicated to provide the recommended professional learning for mathematics specialists

    Nano-Scale Strain-Induced Giant Pseudo-Magnetic Fields and Charging Effects in CVD-Grown Graphene on Copper

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    Scanning tunneling microscopic and spectroscopic (STM/STS) studies of graphene grown by chemical vapor deposition (CVD) on copper reveal that the monolayer carbon structures remaining on copper are strongly strained and rippled, with different regions exhibiting different lattice structures and local electronic density of states (LDOS). The large and non-uniform strain induces pseudo-magnetic field up to ∼ 50 Tesla, as manifested by the integer and fractional pseudo-magnetic field quantum Hall effects (IQHE and FQHE) in the LDOS of graphene. Additionally, ridges appear along the boundaries of different lattice structures, which exhibit excess charging effects. For graphene transferred from copper to SiO_2 substrates after the CVD growth, the average strain and the corresponding charging effects and pseudo-magnetic fields become much reduced. These findings suggest the feasibility of strain-engineering of graphene-based nano-electronics

    Does mass drug administration for the integrated treatment of neglected tropical diseases really work? Assessing evidence for the control of schistosomiasis and soil-transmitted helminths in Uganda

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    This paper was one of four papers commissioned to review the role of social sciences in NTD control by TDR, the Special Programme for Research and Training on Tropical Diseases, which is executed by WHO and co-sponsored by UNICEF, UNDP, the World Bank and WHO.This article has been made available through the Brunel Open Access Publishing Fund.Background: Less is known about mass drug administration [MDA] for neglected tropical diseases [NTDs] than is suggested by those so vigorously promoting expansion of the approach. This paper fills an important gap: it draws upon local level research to examine the roll out of treatment for two NTDs, schistosomiasis and soil-transmitted helminths, in Uganda. Methods: Ethnographic research was undertaken over a period of four years between 2005-2009 in north-west and south-east Uganda. In addition to participant observation, survey data recording self-reported take-up of drugs for schistosomiasis, soil-transmitted helminths and, where relevant, lymphatic filariasis and onchocerciasis was collected from a random sample of at least 10% of households at study locations. Data recording the take-up of drugs in Ministry of Health registers for NTDs were analysed in the light of these ethnographic and social survey data. Results: The comparative analysis of the take-up of drugs among adults revealed that although most long term residents have been offered treatment at least once since 2004, the actual take up of drugs for schistosomiasis and soil-transmitted helminths varies considerably from one district to another and often also within districts. The specific reasons why MDA succeeds in some locations and falters in others relates to local dynamics. Issues such as population movement across borders, changing food supply, relations between drug distributors and targeted groups, rumours and conspiracy theories about the 'real' purpose of treatment, subjective experiences of side effects from treatment, alternative understandings of affliction, responses to social control measures and historical experiences of public health control measures, can all make a huge difference. The paper highlights the need to adapt MDA to local circumstances. It also points to specific generalisable issues, notably with respect to health education, drug distribution and more effective use of existing public health legislation. Conclusion: While it has been an achievement to have offered free drugs to so many adults, current standard practices of monitoring, evaluation and delivery of MDA for NTDs are inconsistent and inadequate. Efforts to integrate programmes have exacerbated the difficulties. Improved assessment of what is really happening on the ground will be an essential step in achieving long-term overall reduction of the NTD burden for impoverished communities.This article is available through the Brunel Open Access Publishing Fund

    ‘Do i care?’ young adults' recalled experiences of early adolescent overweight and obesity: a qualitative study

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    <p>Objective: Individual behaviour change to reduce obesity requires awareness of, and concern about, weight. This paper therefore describes how young adults, known to have been overweight or obese during early adolescence, recalled early adolescent weight-related awareness and concerns. Associations between recalled concerns and weight-, health- and peer-related survey responses collected during adolescence are also examined.</p> <p>Design: Qualitative semi-structured interviews with young adults; data compared with responses to self-report questionnaires obtained in adolescence.</p> <p>Participants: A total of 35 participants, purposively sub-sampled at age 24 from a longitudinal study of a school year cohort, previously surveyed at ages 11, 13 and 15. Physical measures during previous surveys allowed identification of participants with a body mass index (BMI) indicative of overweight or obesity (based on British 1990 growth reference) during early adolescence. Overall, 26 had been obese, of whom 11 had BMI99.6th centile, whereas 9 had been overweight (BMI=95th–97.9th centile).</p> <p>Measures: Qualitative interview responses describing teenage life, with prompts for school-, social- and health-related concerns. Early adolescent self-report questionnaire data on weight-worries, self-esteem, friends and victimisation (closed questions).</p> <p>Results: Most, but not all recalled having been aware of their overweight. None referred to themselves as having been obese. None recalled weight-related health worries. Recollection of early adolescent obesity varied from major concerns impacting on much of an individual's life to almost no concern, with little relation to actual severity of overweight. Recalled concerns were not clearly patterned by gender, but young adult males recalling concerns had previously reported more worries about weight, lower self-esteem, fewer friends and more victimisation in early adolescence; no such pattern was seen among females. Conclusion: The popular image of the unhappy overweight teenager was not borne out. Many obese adolescents, although well aware of their overweight recalled neither major dissatisfaction nor concern. Weight-reduction behaviours are unlikely in such circumstances.</p&gt

    Genotoxicants Target Distinct Molecular Networks in Neonatal Neurons

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    BACKGROUND: Exposure of the brain to environmental agents during critical periods of neuronal development is considered a key factor underlying many neurologic disorders. OBJECTIVES: In this study we examined the influence of genotoxicants on cerebellar function during early development by measuring global gene expression changes. METHODS: We measured global gene expression in immature cerebellar neurons (i.e., granule cells) after treatment with two distinct alkylating agents, methylazoxymethanol (MAM) and nitrogen mustard (HN2). Granule cell cultures were treated for 24 hr with MAM (10–1,000 μM) or HN2 (0.1–20 μM) and examined for cell viability, DNA damage, and markers of apoptosis. RESULTS: Neuronal viability was significantly reduced (p < 0.01) at concentrations > 500 μM for MAM and > 1.0 μM for HN2; this correlated with an increase in both DNA damage and markers of apoptosis. Neuronal cultures treated with sublethal concentrations of MAM (100 μM) or HN2 (1.0 μM) were then examined for gene expression using large-scale mouse cDNA microarrays (27,648). Gene expression results revealed that a) global gene expression was predominantly up-regulated by both genotoxicants; b) the number of down-regulated genes was approximately 3-fold greater for HN2 than for MAM; and c) distinct classes of molecules were influenced by MAM (i.e, neuronal differentiation, the stress and immune response, and signal transduction) and HN2 (i.e, protein synthesis and apoptosis). CONCLUSIONS: These studies demonstrate that individual genotoxicants induce distinct gene expression signatures. Further study of these molecular networks may explain the variable response of the developing brain to different types of environmental genotoxicants

    The Significance of the ProtDeform Score for Structure Prediction and Alignment

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    Background: When a researcher uses a program to align two proteins and gets a score, one of her main concerns is how often the program gives a similar score to pairs that are or are not in the same fold. This issue was analysed in detail recently for the program TM-align with its associated TM-score. It was shown that because the TM-score is length independent, it allows a P-value and a hit probability to be defined depending only on the score. Also, it was found that the TM-scores of gapless alignments closely follow an Extreme Value Distribution (EVD). The program ProtDeform for structural protein alignment was developed recently and is characterised by the ability to propose different transformations of different protein regions. Our goal is to analyse its associated score to allow a researcher to have objective reasons to prefer one aligner over another, and carry out a better interpretation of the output. Results: The study on the ProtDeform score reveals that it is length independent in a wider score range than TM-scores and that PD-scores of gapless (random) alignments also approximately follow an EVD. On the CASP8 predictions, PD-scores and TM-scores, with respect to native structures, are highly correlated (0.95), and show that around a fifth of the predictions have a quality as low as 99.5 % of the random scores. Using the Gold Standard benchmark, ProtDeform has lower probabilities of error than TM-align both at a similar speed. The analysis is extended to homology discrimination showing that, again, ProtDeform offers higher hit probabilities than TM-align. Finally, we suggest using three different P-value

    Crystal structure of serine dehydrogenase from Escherichia coli: important role of the C-terminal region for closed-complex formation.

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    Serine dehydrogenase from Escherichia coli is a homotetrameric enzyme belonging to the short-chain dehydrogenase/reductase (SDR) family. This enzyme catalyses the NADP(+)-dependent oxidation of serine to 2-aminomalonate semialdehyde. The enzyme shows a stereospecificity for β-(3S)-hydroxy acid as a substrate; however, no stereospecificity was observed at the α-carbon. The structures of the ligand-free SerDH and SerDH-NADP(+)-phosphate complex were determined at 1.9 and 2.7 Å resolutions, respectively. The overall structure, including the catalytic tetrad of Asn106, Ser134, Tyr147 and Lys151, shows obvious relationships with other members of the SDR family. The structure of the substrate-binding loop and that of the C-terminal region were disordered in the ligand-free enzyme, whereas these structures were clearly defined in the SerDH-NADP(+) complex as a closed form. Interestingly, the C-terminal region was protruded from the main body and it formed an anti-parallel β-sheet with another C-terminal region on the subunit that is diagonally opposite to that in the tetramer. It is revealed that the C-terminal region possesses the important roles in substrate binding through the stabilization of the substrate-binding loop in the closed form complex. The roles of the C-terminal region along with those of the residues involved in substrate recognition were studied by site-directed mutagenesis

    Synthesis of air‐stable, odorless thiophenol surrogates via Ni‐Catalyzed C−S cross‐coupling

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    Thiophenols are versatile synthetic intermediates whose practical appeal is marred by their air sensitivity, toxicity and extreme malodor. Herein we report an efficient catalytic method for the preparation of S-aryl isothiouronium salts, and demonstrate that these air-stable, odorless solids serve as user-friendly sources of thiophenols in synthesis. Diverse isothiouronium salts featuring synthetically useful functionality are readily accessible via nickelcatalyzed C-S cross-coupling of (hetero)aryl iodides and thiourea. Convenient, chromatography-free isolation of these salts is achieved via precipitation, allowing the methodology to be translated directly to large scales. Thiophenols are liberated from the corresponding isothiouronium salts upon treatment with a weak base, enabling an in situ release / S-functionalization strategy that entirely negates the need to isolate, purify or manipulate these noxious reagent
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