1,625 research outputs found

    Directivity and spacing for the antenna elements

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    The optimum design choice for the MST radar antenna was considered. The following factors are required: directivity and gain; beam width and its symmetry; sidelobe levels, near and wide angle; impedance matching; feeder network losses; polarization diversity; steerability; cost effectiveness; and maintainability. The directivity and related beam forming aspects of various antenna elements and directivity aspects when such elements are formed into an array are discussed. Array performance for important variables, in particular, the spacing of the elements is considered

    Opportunities and challenges of working with gifted and talented students in an urban context: A university-based intervention program

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    This is the author's accepted manuscript. The final published article appeared in Gifted Child Today, 34(1), 2011. Copyright 2011 @ Sage Publications.No abstract available

    Nurturing the young shoots of talent: Using action research for exploration and theory building

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    This is an Author's Accepted Manuscript of an article published in European Early Childhood Education Research Journal, 19(4), 433-450, 2011, copyright Taylor & Francis, available online at: http://www.tandfonline.com/10.1080/1350293X.2011.623515.This paper reports the outcomes of a set of action research projects carried out by teacher researchers in 14 local education authorities in England, working collaboratively with university tutors, over a period of three years. The common aim of all the projects was to explore practical ways of nurturing the gifts and talents of children aged four–seven years. The project was funded by the Department of Education and Skills in England as part of the government's gifted and talented programme. The project teachers felt that their understanding of issues relating to nurturing the gifts and talents of younger children was enhanced through their engagement in the project. It was possible to map the findings of the projects to the English government's National Quality Standards for gifted and talented education which include: (1) identification; (2) effective provision in the classroom; (3) enabling curriculum entitlement and choice; (4) assessment for learning; (5) engaging with community, families and beyond. The findings are also analysed within the framework of good practice in educating children in the first years of schooling. Participating practitioners felt that action research offered them a suitable methodology to explore the complexity of the topic of giftedness through cycles of planning, action and reflection and personal theory building

    Tonsillectomy among children with low baseline acute throat infection consultation rates in UK general practices: a cohort study.

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    OBJECTIVE: To investigate the effectiveness of tonsillectomy in reducing acute throat infection (ATI) consultation rates over 6 years' follow-up among children with low baseline ATI consultation rates. DESIGN: Retrospective cohort study. SETTING: UK general practices from the Clinical Practice Research Datalink. PARTICIPANTS: Children aged 4-15 years with ≤3 ATI consultations during the 3 years prior to 2001 (baseline). 450 children who underwent tonsillectomy (tonsillectomy group) and 13 442 other children with an ATI consultation (comparison group) in 2001. MAIN OUTCOME MEASURES: Mean differences in ATI consultation rates over the first 3 years' and subsequent 3 years' follow-up compared with 3 years prior to 2001 (baseline); odds of ≥3 ATI consultations at the same time points. RESULTS: Among children in the tonsillectomy group, the 3-year mean ATI consultation rate decreased from 1.31 to 0.66 over the first 3 years' follow-up and further declined to 0.60 over the subsequent 3 years' follow-up period. Compared with children who had no operation, those who underwent tonsillectomy experienced a reduction in 3-year mean ATI consultations per child of 2.5 (95% CI 2.3 to 2.6, p<0.001) over the first 3 years' follow-up, but only 1.2 (95% CI 1.0 to 1.4, p<0.001) over the subsequent 3 years' follow-up compared with baseline, respectively. This equates to a mean reduction of 3.7 ATI consultations over a 6-year period and approximates to a mean annual reduction of 0.6 ATI consultations per child, per year, over 6 years' follow-up. Children who underwent tonsillectomy were also much less likely to experience ≥3 ATI consultations during the first 3 years' follow-up (adjusted OR=0.12, 95% CI 0.08 to 0.17) and the subsequent 3 years' follow-up (adjusted OR=0.24, 95% CI 0.14 to 0.41). CONCLUSIONS: Among children with low baseline ATI rates, there was a statistically significant reduction in ATI consultation rates over 6 years' follow-up. However, the relatively modest clinical benefit needs to be weighed against the potential risks and complications associated with surgery

    Extractive Spectrophotometric Determination of Vanadium(V) with N-p-Chlorophenyl-2-naphthohydroxamic Acid and Investigation of Its Solid Complex

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    A simple, selective and sensitive method for the extractive spectrophotometric determination of vanadium(V) using N-p-chlorophenyl- 2-naphthohydroxamic acid (CP-2-NHA) is described. Vanadium( V) is quantitatively extracted from 3-8.4 M HCl as a violet complex with CP-2-NHA into chloroform. Beer\u27s law is applicable in the concentration range 34 and 224 fig of vanadium(V) per 25 ml of chloroform extract. The Sandell sensitivity of the system is 0.0089 μg/cm2 at 530 nm. The method has been satisfactorily employed for the determination of vanadium in steel. The solid complex, VOCI (C11H11N02Cl)2, was prepared and characterised by melting point, elemental analysis, visible and infrared spectra

    Extractive Spectrophotometric Determination of Vanadium(V) with N-p-Chlorophenyl-2-naphthohydroxamic Acid and Investigation of Its Solid Complex

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    A simple, selective and sensitive method for the extractive spectrophotometric determination of vanadium(V) using N-p-chlorophenyl- 2-naphthohydroxamic acid (CP-2-NHA) is described. Vanadium( V) is quantitatively extracted from 3-8.4 M HCl as a violet complex with CP-2-NHA into chloroform. Beer\u27s law is applicable in the concentration range 34 and 224 fig of vanadium(V) per 25 ml of chloroform extract. The Sandell sensitivity of the system is 0.0089 μg/cm2 at 530 nm. The method has been satisfactorily employed for the determination of vanadium in steel. The solid complex, VOCI (C11H11N02Cl)2, was prepared and characterised by melting point, elemental analysis, visible and infrared spectra

    Mathematically gifted and talented learners: Theory and practice

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    This is an Author's Accepted Manuscript of an article published in International Journal of Mathematical Education in Science and Technology, 40(2), 213-228, 2009, copyright Taylor & Francis, available online at: http://www.tandfonline.com/10.1080/00207390802566907.There is growing recognition of the special needs of mathematically gifted learners. This article reviews policy developments and current research and theory on giftedness in mathematics. It includes a discussion of the nature of mathematical ability as well as the factors that make up giftedness in mathematics. The article is set in the context of current developments in Mathematics Education and Gifted Education in the UK and their implications for Science and Technology. It argues that early identification and appropriate provision for younger mathematically promising pupils capitalizes on an intellectual resource which could provide future mathematicans as well as specialists in Science or Technology. Drawing on a Vygotskian framework, it is suggested that the mathematically gifted require appropriate cognitive challenges as well as attitudinally and motivationally enhancing experiences. In the second half of this article we report on an initiative in which we worked with teachers to identify mathematically gifted pupils and to provide effective enrichment support for them, in a number of London Local Authorities. A number of significant issues are raised relating to the identification of mathematical talent, enrichment provision for students and teachers’ professional development

    A simple combinatorial proof of Shapiro's Catalan convolution

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    Shapiro proved an elegant convolution formula involving Catalan numbers of even index. This paper gives a simple combinatorial proof of his formula. In addition, we show that it is equivalent with the alternating convolution formula of central binomial coefficients

    Comparison of standard short infusion versus prolonged infusion of Doxorubicin in relation to its cardiotoxicity in South Indian population

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    Background: Anthracycline is one of the commonly used chemotherapeutic agents in the treatment of malignancies and their efficacy is undermined by potential life-threatening cardiotoxicity.  The aim of this study is to compare the cardiotoxicity in patients receiving standard short infusion (15-30 minutes) versus prolonged infusion (6 hours) of doxorubicin in the study group.Methods: In this study 80 patients who were planned for treatment with Doxorubicin >200 mg/m2 were included in this study and they were randomly allotted to either of the treatment group. Each patient was assessed clinically (History, Pulse rate, Blood pressure) along with ECG ,ECHO prior to initiation of chemotherapy, after completion of 200 mg/m2 of Doxorubicin, 3 months and 6 months after chemotherapy.Results: There were 40 patients in each group, and they received a total of 384 cycles of Doxorubicin containing regimens according to respective protocols. The median number of cycles was four (range four to six cycles). The mean cumulative dose of doxorubicin was 271.5 mg/m2 in the group which received standard short infusion and 264 mg/m2 in the group which received the drug by prolonged infusion. However, none of the patients developed any cardiac symptoms during or after the planned chemotherapy nor was there a drop in ejection fraction on serial ECHO.Conclusions: There was no benefit of prolonged infusion of doxorubicin as compared to the standard rapid infusion in terms of doxorubicin induced cardiotoxicity. At present, standard rapid infusion is the best option
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