586 research outputs found

    Flight feasibility assessment of shuttle/LANDSAT-D missions

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    Because of performance limitations, the shuttle cannot rendezvous with the LANDSAT D satellite in its primary orbit; the actual rendezvous altitude is a function of the performance of the two LANDSAT vehicles and of the shuttle. The feasibility of retrieving LANDSAT D from a 210 n.mi. orbit, following delivery of LANDSAT D to a 200 n.mi. orbit was assessed from an orbital analysis point of view. Parameters such as orbital altitude, phasing and length of rendezvous, which affect flight design for this flight are identified. The results of a study made for delivery to a 235 n. mi. orbit followed by retrieval from 245 n. mi. are included

    OTX2 (orthodenticle homeobox 2)

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    Review on OTX2 (orthodenticle homeobox 2), with data on DNA, on the protein encoded, and where the gene is implicated

    Situated Identities of Young, African American Fathers in Low-Income Urban Settings

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    Young, low-income, African American fathers have been at the center of research, practice, and policy on families over the past decade. This article uses a voicing analytic technique to examine identities among young, low-income, African American fathers living in an urban setting; the intersections of these identities; and the fathers\u27 perceptions of the influences of familial, peer, and legal systems as barriers and resources in their development as fathers and the sustainability of their fathering roles. The primary questions addressed urban fathers\u27 representations of their transition to fatherhood, intergenerational relationships, transformative events, and visions of a possible self. Results from a survey, focus groups, and interviews suggest that the fathers seek to reinvent themselves and reconstruct their identities by separating from street life, redefine home as a place of stability, and challenge the practices of social and legal systems that appear to work against their responsible fathering

    Validation of an experimental setup to study atmospheric heterogeneous ozonolysis of semi-volatile organic compounds

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    International audienceThere is currently a need for reliable experimental procedures to follow the heterogeneous processing simulating the atmospheric conditions. This work offers an alternative experimental device to study the behaviour of semi-volatile organic compounds (SVOC) that presumably exhibit extremely slow reactivity (e.g. pesticides) towards the atmospheric oxidants such as ozone and OH. Naphthalene was chosen as a test compound since it was widely studied in the past and hence represents a good reference. Prior to ozone exposure, the gaseous naphthalene was adsorbed via gas-solid equilibrium on silica and XAD-4 particles. Then, the heterogeneous reaction of ozone with adsorbed naphthalene was investigated in specially designed flow tube reactors. After the reaction, the remaining naphthalene (adsorbed on particles surface) was extracted, filtered and analyzed by Gas Chromatography-Flame Ionization Detector (GC-FID). Thus, the kinetics results were obtained following the consumption of naphthalene. Using this procedure, the rate constants of heterogeneous ozonolysis of naphthalene (kO3 silica=2.26 (±0.09)×10−17 cm3 molec−1 s−1 and kO3 XAD-4=4.29 (±1.06)×10−19 cm3 molec−1 s−1) were determined for silica and XAD-4 particles, at 25°C and relative humidity <0.7%. The results show that the nature of the particles significantly affects the kinetics and that heterogeneous ozonolysis of naphthalene is faster than its homogeneous ozonolysis in the gas phase

    Teacher Identity in the Context of Literacy Teaching: Three Explorations of Classroom Positioning and Interaction in Secondary Schools

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    This article presents the results of three separate studies of literacy teaching and learning in the U.S. that explore the social functions of language, specifically focused on the identity development of literacy learners and teachers. Each study offers a detailed account of how literate identities are constructed and enacted and the positive and negative consequences that occur for teachers and students when they are enacted. Taken together, these three studies demonstrate how teachers’ and students’ understandings of identity can promote or inhibit literacy teaching and learning

    Grasping the dialogical nature of acculturation

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    In this interesting article, Andreouli (2013). Identity and acculturation: The case of naturalised citizens in Britain. Culture & Psychology, 19, 1–47) presents a dialogical perspective on acculturation. To support this perspective, the author integrates the Dialogical Self Theory and the Social Representations Theory. Drawing on her theoretical explanation, we develop a conceptual review focused on two pairs of constructs – social representations/I-positions and polyphasia/polyphonia. Andreouli’s empirical study allowed her to operationalize some critiques about the two-dimensional perspective and its strategies on acculturation. Nevertheless, it seems that the author ends up replicating a more conventional and dual way of thinking. Their results give us privileged access to the negotiation of meanings and activation of promoter signs or, in other words, to the dialogical dynamics between I-positions. In this respect, we suggest that the assumption of a more dialogic and semiotic lens could be an interesting further development to this study

    HAGE (DDX43) is a biomarker for poor prognosis and a predictor of chemotherapy response in breast cancer

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    Background: HAGE protein is a known immunogenic cancer-specific antigen. Methods: The biological, prognostic and predictive values of HAGE expression was studied using immunohistochemistry in three cohorts of patients with BC (n=2147): early primary (EP-BC; n=1676); primary oestrogen receptor-negative (PER-BC; n=275) treated with adjuvant anthracycline-combination therapies (Adjuvant-ACT); and primary locally advanced disease (PLA-BC) who received neo-adjuvant anthracycline-combination therapies (Neo-adjuvant-ACT; n=196). The relationship between HAGE expression and the tumour-infiltrating lymphocytes (TILs) in matched prechemotherapy and postchemotherapy samples were investigated. Results: Eight percent of patients with EP-BC exhibited high HAGE expression (HAGEþ) and was associated with aggressive clinico-pathological features (Ps<0.01). Furthermore, HAGEþexpression was associated with poor prognosis in both univariate and multivariate analysis (Ps<0.001). Patients with HAGE+ did not benefit from hormonal therapy in high-risk ER-positive disease. HAGE+ and TILs were found to be independent predictors for pathological complete response to neoadjuvant-ACT; P<0.001. A statistically significant loss of HAGE expression following neoadjuvant-ACT was found (P=0.000001), and progression-free survival was worse in those patients who had HAGE+ residual disease (P=0.0003). Conclusions: This is the first report to show HAGE to be a potential prognostic marker and a predictor of response to ACT in patients with BC
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