538 research outputs found

    F-theory and Neutrinos: Kaluza-Klein Dilution of Flavor Hierarchy

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    We study minimal implementations of Majorana and Dirac neutrino scenarios in F-theory GUT models. In both cases the mass scale of the neutrinos m_nu ~ (M_weak)^2/M_UV arises from integrating out Kaluza-Klein modes, where M_UV is close to the GUT scale. The participation of non-holomorphic Kaluza-Klein mode wave functions dilutes the mass hierarchy in comparison to the quark and charged lepton sectors, in agreement with experimentally measured mass splittings. The neutrinos are predicted to exhibit a "normal" mass hierarchy, with masses m_3,m_2,m_1 ~ .05*(1,(alpha_GUT)^(1/2),alpha_GUT) eV. When the interactions of the neutrino and charged lepton sectors geometrically unify, the neutrino mixing matrix exhibits a mild hierarchical structure such that the mixing angles theta_23 and theta_12 are large and comparable, while theta_13 is expected to be smaller and close to the Cabibbo angle: theta_13 ~ theta_C ~ (alpha_GUT)^(1/2) ~ 0.2. This suggests that theta_13 should be near the current experimental upper bound.Comment: v2: 83 pages, 10 figures, references adde

    Analysis of dental care of children receiving comprehensive care under general anaesthesia at a teaching hospital in England

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    Objectives: This study aimed to analyse the characteristics of comprehensive dental care provided under general anaesthesia (CDGA) and to review the additional treatment required by children over the 6 years subsequent to CDGA. Method: Information collected from hospital records for the 6-year period following the first CDGA included the types of dental treatment performed at CDGA, the return rates for follow-up appointments, further treatment required subsequent to CDGA and the types of dental treatment performed at repeat DGA. Results: The study population consisted of 263 children, of whom 129 had a significant medical history, with mean age of 6.7 years. The results revealed that the waiting time for CDGA was significantly shorter in children who had a significant medical history, with 49 % being admitted for CDGA within 3 months of pre-GA assessment, as compared to 29 % of healthy children. 67 % of children had follow-up care recorded, with a slightly higher proportion of children with significant medical history returning for follow-up [70 % (90/129)] compared with 65 % (87/134) of healthy children. Re-treatment rates were 34 % (88/263), the majority of cases being treated under local analgesia (42/88). 34 of 263 children had repeat DGA (12.9 %). Of these 71 % (24/34) were children with significant medical history. The mean age at repeat DGA was 9 years. In 25 of 34 children (74 %), repeat DGA was due to trauma, oral pathology, supernumerary removal, hypomineralized teeth or new caries of previously sound or un-erupted teeth at CDGA. The ratio of extraction over restoration (excluding fissure sealants) performed at repeat DGA was 2.8, compared with the ratio of 1.3 in the initial CDGA. Conclusions: There was a higher ratio of extraction over restorations at the repeat DGA. This suggests that the prescribed treatments at repeat DGA were more aggressive as compared to the initial CDGA in 1997. The majority of the treatment required at repeat DGA was to treat new disease

    Clinical capabilities of graduates of an outcomes-based integrated medical program

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    <p>Abstract</p> <p>Background</p> <p>The University of New South Wales (UNSW) Faculty of Medicine replaced its old content-based curriculum with an innovative new 6-year undergraduate entry outcomes-based integrated program in 2004. This paper is an initial evaluation of the perceived and assessed clinical capabilities of recent graduates of the new outcomes-based integrated medical program compared to benchmarks from traditional content-based or process-based programs.</p> <p>Method</p> <p>Self-perceived capability in a range of clinical tasks and assessment of medical education as preparation for hospital practice were evaluated in recent graduates after 3 months working as junior doctors. Responses of the 2009 graduates of the UNSW’s new outcomes-based integrated medical education program were compared to those of the 2007 graduates of UNSW’s previous content-based program, to published data from other Australian medical schools, and to hospital-based supervisor evaluations of their clinical competence.</p> <p>Results</p> <p>Three months into internship, graduates from UNSW’s new outcomes-based integrated program rated themselves to have good clinical and procedural skills, with ratings that indicated significantly greater capability than graduates of the previous UNSW content-based program. New program graduates rated themselves significantly more prepared for hospital practice in the confidence (reflective practice), prevention (social aspects of health), interpersonal skills (communication), and collaboration (teamwork) subscales than old program students, and significantly better or equivalent to published benchmarks of graduates from other Australian medical schools. Clinical supervisors rated new program graduates highly capable for teamwork, reflective practice and communication.</p> <p>Conclusions</p> <p>Medical students from an outcomes-based integrated program graduate with excellent self-rated and supervisor-evaluated capabilities in a range of clinically-relevant outcomes. The program-wide curriculum reform at UNSW has had a major impact in developing capabilities in new graduates that are important for 21<sup>st</sup> century medical practice.</p

    Haiku - a Scala combinator toolkit for semi-automated composition of metaheuristics

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    There is an emerging trend towards the automated design of metaheuristics at the software component level. In principle, metaheuristics have a relatively clean decomposition, where well-known frameworks such as ILS and EA are parametrised by variant components for acceptance, perturbation etc. Automated generation of these frameworks is not so simple in practice, since the coupling between components may be implementation specific. Compositionality is the ability to freely express a space of designs ‘bottom up’ in terms of elementary components: previous work in this area has used combinators, a modular and functional approach to componentisation arising from foundational Computer Science. In this article, we describeHaiku, a combinator tool-kit written in the Scala language, which builds upon previous work to further automate the process by automatically composing the external dependencies of components. We provide examples of use and give a case study in which a programatically-generated heuristic is applied to the Travelling Salesman Problem within an Evolutionary Strategies framework

    Social representations and the politics of participation

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    Recent work has called for the integration of different perspectives into the field of political psychology (Haste, 2012). This chapter suggests that one possible direction that such efforts can take is studying the role that social representations theory (SRT) can play in understanding political participation and social change. Social representations are systems of common-sense knowledge and social practice; they provide the lens through which to view and create social and political realities, mediate people's relations with these sociopolitical worlds and defend cultural and political identities. Social representations are therefore key for conceptualising participation as the activity that locates individuals and social groups in their sociopolitical world. Political participation is generally seen as conditional to membership of sociopolitical groups and therefore is often linked to citizenship. To be a citizen of a society or a member of any social group one has to participate as such. Often political participation is defined as the ability to communicate one's views to the political elite or to the political establishment (Uhlaner, 2001), or simply explicit involvement in politics and electoral processes (Milbrath, 1965). However, following scholars on ideology (Eagleton, 1991; Thompson, 1990) and social knowledge (Jovchelovitch, 2007), we extend our understanding of political participation to all social relations and also develop a more agentic model where individuals and groups construct, develop and resist their own views, ideas and beliefs. We thus adopt a broader approach to participation in comparison to other political-psychological approaches, such as personality approaches (e.g. Mondak and Halperin, 2008) and cognitive approaches or, more recently, neuropsychological approaches (Hatemi and McDermott, 2012). We move away from a focus on the individual's political behaviour and its antecedents and outline an approach that focuses on the interaction between psychological and political phenomena (Deutsch and Kinnvall, 2002) through examining the politics of social knowledge

    The late radiotherapy normal tissue injury phenotypes of telangiectasia, fibrosis and atrophy in breast cancer patients have distinct genotype-dependent causes

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    The relationship between late normal tissue radiation injury phenotypes in 167 breast cancer patients treated with radiotherapy and: (i) radiotherapy dose (boost); (ii) an early acute radiation reaction and (iii) genetic background was examined. Patients were genotyped at single nucleotide polymorphisms (SNPs) in eight candidate genes. An early acute reaction to radiation and/or the inheritance of the transforming growth factor-β1 (TGFβ1 −509T) SNP contributed to the risk of fibrosis. In contrast, an additional 15 Gy electron boost and/or the inheritance of X-ray repair cross-complementing 1 (XRCC1) (R399Q) SNP contributed to the risk of telangiectasia. Although fibrosis, telangiectasia and atrophy, all contribute to late radiation injury, the data suggest that they have distinct underlying genetic and radiobiological causes. Fibrosis risk is associated with an inflammatory response (an acute reaction and/or TGFβ1), whereas telangiectasia is associated with vascular endothelial cell damage (boost and/or XRCC1). Atrophy is associated with an acute response, but the genetic predisposing factors that determine the risk of an acute response or atrophy have yet to be identified. A combined analysis of two UK breast cancer patient studies shows that 8% of patients are homozygous (TT) for the TGFβ1 (C-509T) variant allele and have a 15-fold increased risk of fibrosis following radiotherapy (95% confidence interval: 3.76–60.3; P=0.000003) compared with (CC) homozygotes

    Assessment of left ventricular diastolic function in children after successful repair of aortic coarctation

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    The purpose of the study was an assessment of left ventricular diastolic function in children after the successful repair of aortic coarctation (CoA). The prospective study concerned 32 pediatric patients after the CoA surgery. Tissue Doppler imaging parameters including strain and strain rate and the conventional echocardiographic indexes were analyzed in patients and healthy controls. Analysis of mitral annulus velocities, E–E′ ratio, strain, and strain rate of left ventricular mid-cavity segments and conventional indexes of mitral inflow showed the worsening of left ventricular diastolic mechanics in the study group compared to healthy controls. The E/E′ ratio was significantly higher in the study group compared to the control group (8.30 ± 3.24 vs. 6.95 ± 1.36; p < 0.05). The early diastolic strain rate to late diastolic strain rate ratio as well as early to late diastolic strain ratio of the left ventricular mid-cavity segments were significantly lower in the study group compared to healthy controls (1.81 ± 0.63 vs. 3.74 ± 1.53; p < 0.001 and 1.20 ± 0.49 vs. 3.41 ± 1.26; p < 0.001). No differences of the pulmonary venous flow parameters between those two groups were observed. The left ventricular diastolic mechanics in hypertensive patients after CoA repair did not differ from normotensive subjects. Hypertensive and normotensive children after surgical repair of CoA are found to have worsening of the left ventricular diastolic mechanics suggesting the impairment of the active myocardial relaxation

    Temporal bone verrucous carcinoma: outcomes and treatment controversy

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    Verrucous carcinoma is a rare tumor that presents in the head and neck with the most common sites being the oral cavity and larynx. Fourteen cases of verrucous carcinoma of the temporal bone have been described in literature; this study aims to examine treatment outcomes and discuss the controversy surrounding postoperative radiation. The study design included a literature review along with individual case report in the setting of a tertiary care medical center. Outcome analysis of all cases of verrucous carcinoma of the temporal bone, which are documented in the English literature, and presentation of a single patient report including gross, histologic and radiologic analyses were performed. The longest recorded survival for verrucous carcinoma of the temporal bone occurs in patients treated with surgery alone. Poorer outcomes for patients treated with adjuvant (chemo)radiation may be due to more advanced stage of disease at the time of treatment. Early reports of radiation leading to tumor dedifferentiation or early recurrence are not supported by more recent studies. Whether adjuvant radiation therapy is indicated in verrucous carcinoma of the temporal bone remains controversial
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