625 research outputs found

    PROF. DR HAB. ALEKSANDER TOBIS (1932-2012)

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    On affinity relating two positive measures and the connection coefficients between polynomials orthogonalized by these measures

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    We consider two positive, normalized measures dA(x) and dB(x) related by the relationship dA(x)=(C/(x+D))dB(x) or by dA(x) = (C/(x^2+E))dB(x) and dB(x) is symmetric. We show that then the polynomial sequences {a_{n}(x)}, {b_{n}(x)} orthogonal with respect to these measures are related by the relationship a_{n}(x)=b_{n}(x)+{\kappa}_{n}b_{n-1}(x) or by a_{n}(x) = b_{n}(x) + {\lambda}_{n}b_{n-2}(x) for some sequences {{\kappa}_{n}} and {{\lambda}_{n}}. We present several examples illustrating this fact and also present some attempts for extensions and generalizations. We also give some universal identities involving polynomials {b_{n}(x)} and the sequence {{\kappa}_{n}} that have a form of Fourier series expansion of the Radon--Nikodym derivative of one measure with respect to the other

    In or out? Barriers and facilitators to refugee-background young people accessing mental health services

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    Refugee young people have been identified as a group with high risk for mental health problems, due to their experience of trauma, forced migration, and stressors associated with settlement. A high prevalence of mental health problems is reported in this group, however some research suggests refugee young people have low rates of mental health service access. There is little information available on barriers and facilitators to mental service delivery for this group. Using data from 15 focus groups and five key informant interviews with a total of 115 service providers from 12 agencies in Melbourne, Australia, this paper explores barriers and facilitators to engaging young people from refugee backgrounds with mental health services. Eight key themes emerged: cultural concepts of mental health, illness, and treatment; service accessibility; trust; working with interpreters; engaging family and community; the style and approach of mental health providers; advocacy; and continuity of care

    The smallest eigenvalue of Hankel matrices

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    Let H_N=(s_{n+m}),n,m\le N denote the Hankel matrix of moments of a positive measure with moments of any order. We study the large N behaviour of the smallest eigenvalue lambda_N of H_N. It is proved that lambda_N has exponential decay to zero for any measure with compact support. For general determinate moment problems the decay to 0 of lambda_N can be arbitrarily slow or arbitrarily fast. In the indeterminate case, where lambda_N is known to be bounded below by a positive constant, we prove that the limit of the n'th smallest eigenvalue of H_N for N tending to infinity tends rapidly to infinity with n. The special case of the Stieltjes-Wigert polynomials is discussed

    Improving access to and engagement with mental health services among young people from refugee backgrounds: service user and provider perspectives

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    Limited research has been conducted worldwide on the experiences that children and young people from refugee backgrounds have with mental health services, despite evidence that they have significant vulnerability to the development of mental health problems and to suicidal behaviour and that those with mental ill-health typically underutilise services. The authors were particularly interested in barriers and facilitators to service access and engagement, and conducted two qualitative research projects to improve understanding of the issues – the first with service providers experienced in the refugee area and the second with young refugee service users. The aim of this project was to compare the perspectives of professionals and service users and to identify similarities and differences. The perspectives of the service users and providers were strikingly similar. The analysis identified 21 implications for policy makers, agencies and practitioners, which ranged from issues concerning cultural sensitivity, background matching and mental health literacy to accessibility, setting boundaries and expectations and implementing a holistic and outreach approach. There is a range of specific, practical measures that policy makers and service providers can introduce to enhance access to and engagement with mental health services for young people from refugee backgrounds

    Motion analysis of elite Polish soccer goalkeepers throughout a season

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    The study aims were to determine the distance covered by goalkeepers during matches in the context of game duration and result, to identify the area of their most frequent activity, and to assess goalkeepers' involvement in games finished with a win, draw, or loss. The investigation was based on two innovative tools: the goalkeeper's activity index (GAI) and an analysis of 5-min periods. A video tracking system was used to monitor 17 goalkeepers from Polish National League teams during 15 matches. The GAI was applied to assess their involvement in the game. Elite goalkeepers covered 72.7%, 25.8%, and 2.5% of the distance during the game by walking/jogging, running, and sprinting, respectively. The distances covered in lost, won, and drawn matches turned out similar (mean \ub1 SD: 4800 \ub1 906 m, 4696 \ub1 1033 m, and 4660 \ub1 754 m, respectively). There were no significant differences between the distances covered in the first and second halves. The area of most frequent activity was the middle sector of the penalty area between the goal and penalty area lines. ANOVA results showed that in drawn matches, goalkeepers' activity significantly differed in mean values of the GAI in comparison with that in won and lost games (p = 0.034, p = 0.039, respectively). It was noted that goalkeepers tended to intervene more often in games where their team was winning rather than in those with a losing result. Their direct involvement in defending the goal was the lowest in drawn games

    The Ultrasensitivity of Living Polymers

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    Synthetic and biological living polymers are self-assembling chains whose chain length distributions (CLDs) are dynamic. We show these dynamics are ultrasensitive: even a small perturbation (e.g. temperature jump) non-linearly distorts the CLD, eliminating or massively augmenting short chains. The origin is fast relaxation of mass variables (mean chain length, monomer concentration) which perturbs CLD shape variables before these can relax via slow chain growth rate fluctuations. Viscosity relaxation predictions agree with experiments on the best-studied synthetic system, alpha-methylstyrene.Comment: 4 pages, submitted to Phys. Rev. Let

    Hairpin structure within the 3′UTR of DNA polymerase β mRNA acts as a post-transcriptional regulatory element and interacts with Hax-1

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    Aberrant expression of DNA polymerase β, a key enzyme involved in base excision repair, leads to genetic instability and carcinogenesis. Pol β expression has been previously shown to be regulated at the level of transcription, but there is also evidence of post-transcriptional regulation, since rat transcripts undergo alternative polyadenylation, and the resulting 3′UTR contain at least one regulatory element. Data presented here indicate that RNA of the short 3′UTR folds to form a strong secondary structure (hairpin). Its regulatory role was established utilizing a luciferase-based reporter system. Further studies led to the identification of a protein factor, which binds to this element—the anti-apoptotic, cytoskeleton-related protein Hax-1. The results of in vitro binding analysis indicate that the formation of the RNA–protein complex is significantly impaired by disruption of the hairpin motif. We demonstrate that Hax-1 binds to Pol β mRNA exclusively in the form of a dimer. Biochemical analysis revealed the presence of Hax-1 in mitochondria, but also in the nuclear matrix, which, along with its transcript-binding properties, suggests that Hax-1 plays a role in post-transcriptional regulation of expression of Pol β

    Group Pregnancy Care for refugee background women: a codesigned, multimethod evaluation protocol applying a community engagement framework and an interrupted time series design.

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    IntroductionPregnancy and early parenthood are key opportunities for interaction with health services and connecting to other families at the same life stage. Public antenatal care should be accessible to all, however barriers persist for families from refugee communities to access, navigate and optimise healthcare during pregnancy. Group Pregnancy Care is an innovative model of care codesigned with a community from a refugee background and other key stakeholders in Melbourne, Australia. Group Pregnancy Care aims to provide a culturally safe and supportive environment for women to participate in antenatal care in a language they understand, to improve health literacy and promote social connections and inclusion. This paper outlines Froup Pregnancy Care and provides details of the evaluation framework.Methods and analysisThe evaluation uses community-based participatory research methods to engage stakeholders in codesign of evaluation methods. The study is being conducted across multiple sites and involves multiple phases, use of quantitative and qualitative methods, and an interrupted time series design. Process and cost-effectiveness measures will be incorporated into quality improvement cycles. Evaluation measures will be developed using codesign and participatory principles informed by community and stakeholder engagement and will be piloted prior to implementation.Ethics and disseminationEthics approvals have been provided by all six relevant authorities. Study findings will be shared with communities and stakeholders via agreed pathways including community forums, partnership meetings, conferences, policy and practice briefs and journal articles. Dissemination activities will be developed using codesign and participatory principles
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