316 research outputs found

    Four functional roles for case studies in emerging adulthood research

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    Case studies have four functional roles which, if more widely embraced, can help to advance theory and methodology in the study of emerging adults. These functions are: case-based theory development, individual-level prediction testing, theory exemplification, and idiographic psychobiography. We describe these functions and provide examples of how each one can add depth, richness and rigour to the burgeoning theory and research on emerging adulthood. We also discuss specifiability (the capacity of a theory to make predictions about, explain and interpret individuals) as a criterion of validity, to be considered as equivalent in status to the external validity criterion of generalizability. Finally we consider the protocols for case study sampling, including intensity sampling, deviant case sampling and significant case sampling

    Quantum Metrology Triangle Experiments: A Status Review

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    Quantum Metrology Triangle experiments combine three quantum electrical effects (the Josephson effect, the quantum Hall effect and the single-electron transport effect) used in metrology. These experiments allow important fundamental consistency tests on the validity of commonly assumed relations between fundamental constants of nature and the quantum electrical effects. This paper reviews the history, results and the present status and perspectives of Quantum Metrology Triangle experiments. It also reflects on the possible implications of results for the knowledge on fundamental constants and the quantum electrical effects.Comment: 36 pages, 8 figure

    Professionalism, Golf Coaching and a Master of Science Degree: A commentary

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    As a point of reference I congratulate Simon Jenkins on tackling the issue of professionalism in coaching. As he points out coaching is not a profession, but this does not mean that coaching would not benefit from going through a professionalization process. As things stand I find that the stimulus article unpacks some critically important issues of professionalism, broadly within the context of golf coaching. However, I am not sure enough is made of understanding what professional (golf) coaching actually is nor how the development of a professional golf coach can be facilitated by a Master of Science Degree (M.Sc.). I will focus my commentary on these two issues

    Predisposition to Obesity: Should We Target Those Most Susceptible?

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    Obesity prevention should remain a priority, even if there is some suggestion that the epidemic may presently have reached a stable level. However, previous interventions have not been effective in preventing overweight and obesity, and at the same time studies suggest that some subgroups are more predisposed to future obesity. The purpose of this paper is to review interventions on obesity prevention published during the past year, and to examine if interventions targeting predisposed groups or individuals seem more efficient in preventing obesity than studies targeting general populations. Among 15 identified studies, 7 targeted predisposed children or adolescents. More of the studies targeting predisposed individuals were able to show significant effects than the studies targeting general populations. Most studies targeting predisposed defined the predisposition based on ethnicity or socioeconomic status. Thus, we may be more successful in preventing obesity when targeting predisposed individuals, but more studies are needed before a firm conclusion can be drawn

    Topical Oestrogen Keratinises The Human Foreskin and May Help Prevent HIV Infection

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    With the growing incidence of HIV, there is a desperate need to develop simple, cheap and effective new ways of preventing HIV infection. Male circumcision reduces the risk of infection by about 60%, probably because of the removal of the Langerhans cells which are abundant in the inner foreskin and are the primary route by which HIV enters the penis. Langerhans cells form a vital part of the body's natural defence against HIV and only cause infection when they are exposed to high levels of HIV virions. Rather than removing this natural defence mechanism by circumcision, it may be better to enhance it by thickening the layer of keratin overlying the Langerhans cells, thereby reducing the viral load to which they are exposed. We have investigated the ability of topically administered oestrogen to induce keratinization of the epithelium of the inner foreskin. Histochemically, the whole of the foreskin is richly supplied with oestrogen receptors. The epithelium of the inner foreskin, like the vagina, responds within 24 hours to the topical administration of oestriol by keratinization, and the response persists for at least 5 days after the cessation of the treatment. Oestriol, a cheap, readily available natural oestrogen metabolite, rapidly keratinizes the inner foreskin, the site of HIV entry into the penis. This thickening of the overlying protective layer of keratin should reduce the exposure of the underlying Langerhans cells to HIV virions. This simple treatment could become an adjunct or alternative to surgical circumcision for reducing the incidence of HIV infection in men

    Towards an Intelligent Tutor for Mathematical Proofs

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    Computer-supported learning is an increasingly important form of study since it allows for independent learning and individualized instruction. In this paper, we discuss a novel approach to developing an intelligent tutoring system for teaching textbook-style mathematical proofs. We characterize the particularities of the domain and discuss common ITS design models. Our approach is motivated by phenomena found in a corpus of tutorial dialogs that were collected in a Wizard-of-Oz experiment. We show how an intelligent tutor for textbook-style mathematical proofs can be built on top of an adapted assertion-level proof assistant by reusing representations and proof search strategies originally developed for automated and interactive theorem proving. The resulting prototype was successfully evaluated on a corpus of tutorial dialogs and yields good results.Comment: In Proceedings THedu'11, arXiv:1202.453

    Thiothymidine combined with UVA as a potential novel therapy for bladder cancer

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    BACKGROUND: Thiothymidine (S4TdR) can be incorporated into DNA and sensitise cells to DNA damage and cell death following exposure to UVA light. Studies were performed to determine if the combination of S4TdR and UVA could be an effective treatmentfor bladder cancer. METHODS: Uptake and incorporation of S4TdR was determined in rat and human bladder tumour cell lines. Measures of DNA crosslinking and apoptosis were also performed. In vivo activity of the combination of S4TdR and UVA was investigated in an orthotopic model of bladder cancer in rats. RESULTS: Thiothymidine (200 uM) replaced up to 0.63% of thymidine in rat and tumour bladder cancer cells. The combination of S4TdR (10–200 uM) and UVA (1–5 kJm-2) caused apoptosis and cell death at doses that were not toxic alone. Addition of raltitrexed (Astra Zeneca, Alderley Edge, Cheshire, UK) increased the incorporation of S4TdR into DNA (up to 20-fold at IC5) and further sensitised cells to UVA. Cytotoxic effect was associated with crosslinking of DNA, at least partially to protein. Intravenous administration of S4TdR, in combination with UVA delivered directly to the bladder, resulted in an antitumour effect in three of five animals treated. CONCLUSION: These data indicate that the combination of S4TdR and UVA has potential as a treatment for bladder cancer, and give some insight into the mechanism of action. Further work is necessary to optimise the delivery of the two components

    A quantitative analysis of complexity of human pathogen-specific CD4 T cell responses in healthy M. tuberculosis infected South Africans

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    Author Summary: Human pathogen-specific immune responses are tremendously complex and the techniques to study them ever expanding. There is an urgent need for a quantitative analysis and better understanding of pathogen-specific immune responses. Mycobacterium tuberculosis (Mtb) is one of the leading causes of mortality due to an infectious agent worldwide. Here, we were able to quantify the Mtb-specific response in healthy individuals with Mtb infection from South Africa. The response is highly diverse and 66 epitopes are required to capture 80% of the total reactivity. Our study also show that the majority of the identified epitopes are restricted by multiple HLA alleles. Thus, technical advances are required to capture and characterize the complete pathogen-specific response. This study demonstrates further that the approach combining identified epitopes into "megapools" allows capturing a large fraction of the total reactivity. This suggests that this technique is generally applicable to the characterization of immunity to other complex pathogens. Together, our data provide for the first time a quantitative analysis of the complex pathogen-specific T cell response and provide a new understanding of human infections in a natural infection setting
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