264 research outputs found

    What Works in School-Based Programs for Child Abuse Prevention? The Perspectives of Young Child Abuse Survivors

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    Previous research has shown that youth consider school-based child abuse prevention programs as one of the most important strategies for preventing child abuse and neglect. This study asked young child abuse survivors how school-based child abuse prevention programs should be shaped and what program components they perceive as essential. Semi-structured interviews were conducted with 13 Dutch young adults that were a victim of child abuse or neglect. A literature review that resulted in 12 potential program components was used to guide the interviews. All young adults agreed that school-based child abuse prevention programs are important and have positive effects on children’s awareness of child abuse. Teaching children that they are never to blame for child abuse occurrences was considered one of the most important components of school-based programs, next to teaching children how to escape from threatening situations and to find help, increasing children’s social–emotional skills, promoting child abuse related knowledge, recognizing risky situations, and increasing children’s self-esteem. Further, the participants found it important to provide children with aftercare when a school program has ended. Overall, young child abuse survivors have a strong view on what should be addressed in school-based child abuse prevention programs to effectively prevent child abuse

    Tannakian duality for Anderson-Drinfeld motives and algebraic independence of Carlitz logarithms

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    We develop a theory of Tannakian Galois groups for t-motives and relate this to the theory of Frobenius semilinear difference equations. We show that the transcendence degree of the period matrix associated to a given t-motive is equal to the dimension of its Galois group. Using this result we prove that Carlitz logarithms of algebraic functions that are linearly independent over the rational function field are algebraically independent.Comment: 39 page

    Nonintegrability of the two-body problem in constant curvature spaces

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    We consider the reduced two-body problem with the Newton and the oscillator potentials on the sphere S2{\bf S}^{2} and the hyperbolic plane H2{\bf H}^{2}. For both types of interaction we prove the nonexistence of an additional meromorphic integral for the complexified dynamic systems.Comment: 20 pages, typos correcte

    Holonomy of the Ising model form factors

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    We study the Ising model two-point diagonal correlation function C(N,N) C(N,N) by presenting an exponential and form factor expansion in an integral representation which differs from the known expansion of Wu, McCoy, Tracy and Barouch. We extend this expansion, weighting, by powers of a variable λ\lambda, the jj-particle contributions, fN,N(j) f^{(j)}_{N,N}. The corresponding λ \lambda extension of the two-point diagonal correlation function, C(N,N;λ) C(N,N; \lambda), is shown, for arbitrary λ\lambda, to be a solution of the sigma form of the Painlev{\'e} VI equation introduced by Jimbo and Miwa. Linear differential equations for the form factors fN,N(j) f^{(j)}_{N,N} are obtained and shown to have both a ``Russian doll'' nesting, and a decomposition of the differential operators as a direct sum of operators equivalent to symmetric powers of the differential operator of the elliptic integral E E. Each fN,N(j) f^{(j)}_{N,N} is expressed polynomially in terms of the elliptic integrals E E and K K. The scaling limit of these differential operators breaks the direct sum structure but not the ``Russian doll'' structure. The previous λ \lambda-extensions, C(N,N;λ) C(N,N; \lambda) are, for singled-out values λ=cos(πm/n) \lambda= \cos(\pi m/n) (m,nm, n integers), also solutions of linear differential equations. These solutions of Painlev\'e VI are actually algebraic functions, being associated with modular curves.Comment: 39 page

    Fuchs versus Painlev\'e

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    We briefly recall the Fuchs-Painlev\'e elliptic representation of Painlev\'e VI. We then show that the polynomiality of the expressions of the correlation functions (and form factors) in terms of the complete elliptic integral of the first and second kind, K K and E E, is a straight consequence of the fact that the differential operators corresponding to the entries of Toeplitz-like determinants, are equivalent to the second order operator LE L_E which has E E as solution (or, for off-diagonal correlations to the direct sum of LE L_E and d/dt d/dt). We show that this can be generalized, mutatis mutandis, to the anisotropic Ising model. The singled-out second order linear differential operator LE L_E being replaced by an isomonodromic system of two third-order linear partial differential operators associated with Π1 \Pi_1, the Jacobi's form of the complete elliptic integral of the third kind (or equivalently two second order linear partial differential operators associated with Appell functions, where one of these operators can be seen as a deformation of LE L_E). We finally explore the generalizations, to the anisotropic Ising models, of the links we made, in two previous papers, between Painlev\'e non-linear ODE's, Fuchsian linear ODE's and elliptic curves. In particular the elliptic representation of Painlev\'e VI has to be generalized to an ``Appellian'' representation of Garnier systems.Comment: Dedicated to the : Special issue on Symmetries and Integrability of Difference Equations, SIDE VII meeting held in Melbourne during July 200

    Analytic curves in algebraic varieties over number fields

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    We establish algebraicity criteria for formal germs of curves in algebraic varieties over number fields and apply them to derive a rationality criterion for formal germs of functions, which extends the classical rationality theorems of Borel-Dwork and P\'olya-Bertrandias valid over the projective line to arbitrary algebraic curves over a number field. The formulation and the proof of these criteria involve some basic notions in Arakelov geometry, combined with complex and rigid analytic geometry (notably, potential theory over complex and pp-adic curves). We also discuss geometric analogues, pertaining to the algebraic geometry of projective surfaces, of these arithmetic criteria.Comment: 55 pages. To appear in "Algebra, Arithmetic, and Geometry: In Honor of Y.i. Manin", Y. Tschinkel & Yu. Manin editors, Birkh\"auser, 200

    Genetics of human neural tube defects

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    Neural tube defects (NTDs) are common, severe congenital malformations whose causation involves multiple genes and environmental factors. Although more than 200 genes are known to cause NTDs in mice, there has been rather limited progress in delineating the molecular basis underlying most human NTDs. Numerous genetic studies have been carried out to investigate candidate genes in cohorts of patients, with particular reference to those that participate in folate one-carbon metabolism. Although the homocysteine remethylation gene MTHFR has emerged as a risk factor in some human populations, few other consistent findings have resulted from this approach. Similarly, attention focused on the human homologues of mouse NTD genes has contributed only limited positive findings to date, although an emerging association between genes of the non-canonical Wnt (planar cell polarity) pathway and NTDs provides candidates for future studies. Priorities for the next phase of this research include: (i) larger studies that are sufficiently powered to detect significant associations with relatively minor risk factors; (ii) analysis of multiple candidate genes in groups of well-genotyped individuals to detect possible gene–gene interactions; (iii) use of high throughput genomic technology to evaluate the role of copy number variants and to detect ‘private’ and regulatory mutations, neither of which have been studied to date; (iv) detailed analysis of patient samples stratified by phenotype to enable, for example, hypothesis-driven testing of candidates genes in groups of NTDs with specific defects of folate metabolism, or in groups of fetuses with well-defined phenotypes such as craniorachischisis

    A rigidity property of asymptotically simple spacetimes arising from conformally flat data

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    Given a time symmetric initial data set for the vacuum Einstein field equations which is conformally flat near infinity, it is shown that the solutions to the regular finite initial value problem at spatial infinity extend smoothly through the critical sets where null infinity touches spatial infinity if and only if the initial data coincides with Schwarzschild data near infinity.Comment: 37 page

    Prevalences of hyperhomocysteinemia, unfavorable cholesterol profile and hypertension in European populations

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    Item does not contain fulltextBACKGROUND: Hyperhomocysteinemia (HHCY) is a risk factor for cardiovascular diseases (CVD). HHCY may interact with hypertension (HTEN) and an unfavorable cholesterol profile (UNFAVCHOL) to alter the risk of CVD. OBJECTIVES: To estimate the prevalences of HHCY (1) isolated and (2) in combination with UNFAVCHOL and/or HTEN in different age categories. To provide information that may improve the screening and treatment of subjects at risk of CVD. DESIGN: Cross-sectional data on 12,541 men and 12,948 women aged 20 + y were used from nine European studies. RESULTS: The prevalence of isolated HHCY was 8.5% in subjects aged 20-40 y, 4.7% in subjects aged 40-60 y and 5.9% in subjects aged over 60 y. When combining all age groups, 5.3% had isolated HHCY and an additional 5.6% had HHCY in combination with HTEN and/or UNFAVCHOL. The combinations of risk factors increased with age and, except for HHCY&UNFAVCHOL, were more prevalent than predicted by chance. Of the young subjects (20-40 y), 24% suffered from one or more of the investigated CVD risk factors. This figure was 75.1% in the old subjects (60+ years). CONCLUSIONS: A substantial number of subjects in selected European populations have HHCY (10.9%). In half of these cases, subjects suffer also from other CVD risk factors like UNFAVCHOL and HTEN. Older people in particular tend to have more than one risk factor. Healthcare professionals should be aware of this when screening and treating older people not only for the conventional CVD risk factors like UNFAVCHOL and HTEN but also HHCY, as this can easily be reduced through increased intake of folic acid via supplement or foods fortified with folic acid
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