628 research outputs found

    The Lerch Zeta Function II. Analytic Continuation

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    This is the second of four papers that study algebraic and analytic structures associated with the Lerch zeta function. In this paper we analytically continue it as a function of three complex variables. We that it is well defined as a multivalued function on the manifold M equal to C^3 with the hyperplanes corresponding to integer values of the two variables a and c removed. We show that it becomes single valued on the maximal abelian cover of M. We compute the monodromy functions describing the multivalued nature of this function on M, and determine various of their properties.Comment: 29 pages, 3 figures; v2 notation changes, homotopy action on lef

    Body composition in older community-dwelling adults with hip fracture: portable field methods validated by dual-energy X-ray absorptiometry

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    Ageing is associated with weight loss and subsequently poor health outcomes. The present study assessed agreement between two field methods, bioelectrical impedance spectroscopy (BIS) and corrected arm muscle area (CAMA) for assessment of body composition against dual-energy X-ray absorptiometry (DXA), the reference technique. Agreement between two predictive equations estimating skeletal muscle mass (SMM) from BIS against SMM from DXA was also determined. Assessments occurred at baseline < 14 d post-surgery (n 79), and at 6 months (6M; n 75) and 12 months (12M; n 63) in community-living older adults after surgical treatment for hip fracture. The 95 % limits of agreement (LOA) between BIS and DXA, CAMA and DXA and the equations and DXA were assessed using Bland–Altman analyses. Mean bias and LOA for fat-free mass (FFM) between BIS and DXA were: baseline, 0·7 ( − 10·9, 12·4) kg; 6M, − 0·5 ( − 20·7, 19·8) kg; 12M, 0·1 ( − 8·7, 8·9) kg and for SMM between CAMA and DXA were: baseline, 0·3 ( − 11·7, 12·3) kg; 6M, 1·3 ( − 4·5, 7·1) kg; 12M, 0·9 ( − 5·4, 7·2) kg. Equivalent data for predictive equations against DXA were: equation 1: baseline, 15·1 ( − 9·5, 20·6) kg; 6M, 17·1 ( − 12·0, 22·2) kg; 12M, 17·5 ( − 13·0, 22·0) kg; equation 2: baseline, 12·6 ( − 7·3, 19·9) kg; 6M, 14·4 ( − 9·7, 19·1) kg; 12M, 14·8 ( − 10·7, 18·9) kg. Proportional bias (BIS: β = − 0·337, P< 0·001; CAMA: β = − 0·294, P< 0·001) was present at baseline but not at 6M or 12M. Clinicians should be cautious in using these field methods to predict FFM and SMM, particularly in the acute care setting. New predictive equations would be beneficial.This research was supported by the National Health and Medical Research Council (NHMRC), Australia

    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

    Two-body quantum mechanical problem on spheres

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    The quantum mechanical two-body problem with a central interaction on the sphere Sn{\bf S}^{n} is considered. Using recent results in representation theory an ordinary differential equation for some energy levels is found. For several interactive potentials these energy levels are calculated in explicit form.Comment: 41 pages, no figures, typos corrected; appendix D was adde

    Iron bioavailability in two commercial cultivars of wheat: a comparison between wholegrain and white flour and the effects of nicotianamine and 2'-deoxymugineic acid on iron uptake into Caco-2 cells

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    Iron bioavailability in unleavened white and wholegrain bread made from two commercial wheat varieties was assessed by measuring ferritin production in Caco-2 cells. The breads were subjected to simulated gastrointestinal digestion and the digests applied to the Caco-2 cells. Although Riband grain contained a lower iron concentration than Rialto, iron bioavailability was higher. No iron was taken up by the cells from white bread made from Rialto flour or from wholegrain bread from either variety, but Riband white bread produced a small ferritin response. The results probably relate to differences in phytate content of the breads, although iron in soluble monoferric phytate was demonstrated to be bioavailable in the cell model. Nicotianamine, an iron chelator in plants involved in iron transport, was a more potent enhancer of iron uptake into Caco-2 cells than ascorbic acid or 2'-deoxymugineic acid, another metal chelator present in plants

    Adolescent and caregiver perception of family functioning: Relation to suicide ideation and attempts

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    This study assessed the relationship between perceived family functioning and two indicators of suicidality in an adolescent sample. A total of 103 adolescents psychiatrically hospitalized for suicidal ideation and/or behavior completed a battery of self-report questionnaires assessing family functioning, negative affectivity, suicidal ideation in the past week assessed by Beck\u27s Scale for Suicide Ideation (BSS; Beck et al., 1979), and past suicide attempts. Participants\u27 primary caregivers also completed a questionnaire on family functioning. A paired samples t-test evaluated overall discrepancy between adolescent- and caregiver-reported family functioning. Linear and logistic regression models were used to evaluate the simple associations between perceived family functioning and suicidal indicators (BSS and previous attempt status), as well as the associations between perceived family functioning and suicidal indicators after controlling for negative affect. Results indicated that adolescents\u27 ratings of family functioning were significantly worse than caregivers\u27 ratings, and positively associated with BSS scores and a history of suicide attempt. When negative affect was controlled for, adolescent-reported family functioning was significantly associated with BSS, but only trended toward significance with attempt status. Findings suggest that adolescents\u27 perceptions of family functioning may be a key contributing factor to suicidal ideation in adolescents with psychiatric disorders

    Error bounds for the large-argument asymptotic expansions of the Hankel and Bessel functions

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    In this paper, we reconsider the large-argument asymptotic expansions of the Hankel, Bessel and modified Bessel functions and their derivatives. New integral representations for the remainder terms of these asymptotic expansions are found and used to obtain sharp and realistic error bounds. We also give re-expansions for these remainder terms and provide their error estimates. A detailed discussion on the sharpness of our error bounds and their relation to other results in the literature is given. The techniques used in this paper should also generalize to asymptotic expansions which arise from an application of the method of steepest descents.Comment: 32 pages, 2 figures, accepted for publication in Acta Applicandae Mathematica

    Mental Health and School Functioning for Girls in the Child Welfare System : the Mediating Role of Future Orientation and School Engagement

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    This study investigated the association between mental health problems and academic and behavioral school functioning for adolescent girls in the child welfare system and determined whether school engagement and future orientation meditated the relationship. Participants were 231 girls aged between 12 and 19 who had been involved with the child welfare system. Results indicated that 39% of girls reported depressive symptoms in the clinical range and 54% reported posttraumatic symptoms in the clinical range. The most common school functioning problems reported were failing a class (41%) and physical fights with other students (35%). Participants reported a mean number of 1.7 school functioning problems. Higher levels of depression and PTSD were significantly associated with more school functioning problems. School engagement fully mediated the relationship between depression and school functioning and between PTSD and school functioning, both models controlling for age, race, and placement stability. Future orientation was not significantly associated with school functioning problems at the bivariate level. Findings suggest that school engagement is a potentially modifiable target for interventions aiming to ameliorate the negative influence of mental health problems on school functioning for adolescent girls with histories of abuse or neglect

    Relationship between pica and iron nutrition in Johannesburg black adults

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    On direct questioning by a Black staff nurse, 23% of 348 consecutive unselected adult outpatients attending the Johannesburg Non-European Hospital said that they regularly ate earth or ash. The prevalence was higher in the women (33%) than in the men (11 %), and in 50 women with minor gynaecological complaints who were interviewed by a Black psychologist, it was 72%. The quantity eaten varied from an occasional tablespoonful to several handfuls a day. In an attempt to define the reasons for the habit a thematic apperception test was used. A strong association with pregnancy was identified, but the explanation for this was not established. Some subjects claimed that the material was eaten for medicinal purposes, while others merely liked the taste. The effect on iron nutrition appeared to be variable, depending on the ironbinding capacity of the soluble iron content of the material consumed.S. Afr. Med. J., 48. 1655 (1974

    Evaluation of the acceptability and feasibility of a computer-tailored intervention to increase HPV vaccination among young adult women

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    Objective: To examine acceptability and feasibility of a Transtheoretical Model (TTM)-based computer-tailored intervention for increasing HPV vaccination in college-aged women. Participants: 243 women ages 18-26 were recruited between February and May of 2011. Methods: Participants completed the intervention and a 14-item evaluation of intervention content and delivery. Results: Most participants had heard of HPV (91%), but the majority (57%) of participants were in Precontemplation for getting vaccinated. Eighty nine percent of participants rated the CTI positively across all acceptability items, and 91% endorsed intention to get vaccinated after intervention. While average ratings in each demographic subgroup were positive, Hispanic women and participants in more advanced Stages of Change rated the program more favorably than non-Hispanic and earlier stage participants. Additionally, HPV Knowledge was higher among White/Non-Hispanic participants. Conclusions: Initial acceptability and feasibility data for this intervention is promising. Its computer-based, individually-tailored format is state of the art and ideal for inexpensive dissemination
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