1,797 research outputs found
Quality of life of adolescents with cancer: family risks and resources
PURPOSE: The goal of this study was to evaluate the relative contribution of treatment intensity, family sociodemographic risk, and family resources to health-related quality of life (QOL) of 102 adolescents in treatment for cancer. METHODS: Adolescents and parents completed self-report measures of teen QOL, family functioning, and parent-child bonding. Based on parent report of family sociodemographic variables, an additive risk index was computed. A pediatric oncologist rated treatment intensity. RESULTS: Simultaneous regression analyses demonstrated the significant contribution of roles in family functioning and quality of parent-child relationship to prediction of psychosocial QOL (parent and teen-reported) as well as parent-reported teen physical QOL over and above the contribution of treatment intensity. Family sociodemographic risk did not contribute to QOL in these regression analyses. In additional analyses, specific diagnosis, types of treatment and individual sociodemographic risk variables were not associated with QOL. Parent and teen ratings of family functioning and quality of life were concordant. CONCLUSIONS: Family functioning, including quality of parent-child relationship, are central and potentially modifiable resistance factors in teen QOL while under treatment for cancer. Even more important than relying on diagnosis or treatment, screening for roles and relationships early in treatment may be an important aspect of determining risk for poor QOL outcomes
Any -state solutions of the Hulth\'en potential by the asymptotic iteration method
In this article, we present the analytical solution of the radial
Schr\"{o}dinger equation for the Hulth\'{e}n potential within the framework of
the asymptotic iteration method by using an approximation to the centrifugal
potential for any states. We obtain the energy eigenvalues and the
corresponding eigenfunctions for different screening parameters. The wave
functions are physical and energy eigenvalues are in good agreement with the
results obtained by other methods for different values. In order to
demonstrate this, the results of the asymptotic iteration method are compared
with the results of the supersymmetry, the numerical integration, the
variational and the shifted 1/N expansion methods.Comment: 14 pages and 1 figur
Balloon-borne coded aperture telescope for arc-minute angular resolution at hard x-ray energies
We are working on the development of a new balloon-borne telescope, MARGIE (minute-of-arc resolution gamma ray imaging experiment). It will be a coded aperture telescope designed to image hard x-rays (in various configurations) over the 20 - 600 keV range with an angular resolution approaching one arc minute. MARGIE will use one (or both) of two different detection plane technologies, each of which is capable of providing event locations with sub-mm accuracies. One such technology involves the use of cadmium zinc telluride (CZT) strip detectors. We have successfully completed a series of laboratory measurements using a prototype CZT detector with 375 micron pitch. Spatial location accuracies of better than 375 microns have been demonstrated. A second type of detection plane would be based on CsI microfiber arrays coupled to a large area silicon CCD readout array. This approach would provide spatial resolutions comparable to that of the CZT prototype. In one possible configuration, the coded mask would be 0.5 mm thick tungsten, with 0.5 mm pixels at a distance of 1.5 m from the central detector giving an angular resolution of 1 arc-minute and a fully coded field of view of 12 degrees. We review the capabilities of the MARGIE telescope and report on the status of our development efforts and our plans for a first balloon flight
Praziquantel: its use in control of schistosomiasis in sub-Saharan Africa and current research needs
Treatment with praziquantel (PZQ) has become virtually the sole basis of schistosomiasis control in sub-Saharan Africa and elsewhere, and the drug is reviewed here in the context of the increasing rate that it is being used for this purpose. Attention is drawn to our relative lack of knowledge about the mechanisms of action of PZQ at the molecular level, the need for more work to be done on schistosome isolates that have been collected recently from endemic areas rather than those maintained in laboratory conditions for long periods, and our reliance for experimental work mainly on Schistosoma mansoni, little work having been done on S. haematobium. There is no evidence that resistance to PZQ has been induced in African schistosomes as a result of its large-scale use on that continent to date, but there is also no assurance that PZQ and/or schistosomes are in any way unique and that resistant organisms will not be selected as a result of widespread drug usage. The failure of PZQ to produce complete cures in populations given a routine treatment should therefore solicit considerable concern. With few alternatives to PZQ currently available and/or on the horizon, methods to monitor drug-susceptibility in African schistosomes need to be devised and used to help ensure that this drug remains effective for as long a time as possibl
An Initial Application of a Biopsychosocial Framework to Predict Posttraumatic Stress Following Pediatric Injury
Objectives—Each year millions of children suffer from unintentional injuries that result in poor emotional and physical health. This study examined selected biopsychosocial factors (i.e., child heart rate, peritrauma appraisals, early coping, trauma history) to elucidate their roles in promoting emotional recovery following injury. The study evaluated specific hypotheses that threat appraisals (global and trauma-specific) and coping would predict subsequent posttraumatic stress symptoms (PTSS), that coping would mediate the association between early and later PTSS, and that heart rate would predict PTSS and appraisals would mediate this association.
Method—Participants were 96 children hospitalized for injury and assessed at 3 time points: T1 (within 2 weeks of injury), T2 (6-week follow-up), and T3 (12-week follow-up). Participants completed measures of trauma history and appraisals at T1, coping at T2, and PTSS at T1, T2, and T3. Heart rate was abstracted from medical records. Structural equation modeling was employed to evaluate study hypotheses.
Results—Heart rate was not associated with PTSS or appraisals. Models including trauma history, appraisals, coping, and PTSS were constructed to test other study hypotheses and fit the data well. T1 global and trauma-specific threat appraisals were associated with T1 PTSS; T2 avoidant coping was a significant mediator of the relation between T1 and T3 PTSS.
Conclusions—Findings confirm a role for appraisals and coping in the development of PTSS over the weeks following pediatric injury. Early appraisals and avoidant coping may be appropriate targets for prevention and early intervention. Future researchers should further explicate the utility of a biopsychosocial framework in predicting PTSS
Bloch surface waves, a 2D platform for planar optical integration
A novel platform suitable for fundamental investigations of light propagation through micro-and nanostructures will be discussed. This platform is based on a dielectric multilayer that sustains Bloch surface waves (BSWs). BSWs are electromagnetic surface waves excited at the interface between a truncated periodic dielectric multilayer and a surrounding media. The modification of the top surface to customize a complete 2D micro-system can be produced using e-beam writing, optical lithography or other patterning techniques. The results obtained confirm the possibility of developing a robust multilayer platform that would pave the way for integration of photonic components in photonic chips using standard wafer-scale production
Nitrogen-doped, FeNi alloy nanoparticle-decorated graphene as an efficient and stable electrode for electrochemical supercapacitors in acid medium
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Too Much of Two Good Things: Explicating the Limited Complementarity Between Drivers of MNC Headquarters’ Absorptive Capacity
This study examines how multinational corporation (MNC) knowledge management mechanisms (systems, coordination and socialization) and international exposure affect MNC headquarters' absorptive capacity (AC). We build on Cohen and Levinthal's (Admin Sci Quart 35(1):128–152, 1990, https://doi.org/10.2307/2393553) under-researched trade-off between the inward- and outward-looking drivers of AC in the context of the MNC international knowledge transfer. First, we hypothesize that knowledge management mechanisms (the inward-looking driver) and international exposure (the outward-looking driver) directly influence headquarters' AC. Our findings from a sample of 106 Brazilian and Portuguese MNC headquarters support this view. Second, because "not-invented-here" syndrome and distance can affect knowledge flows from subsidiaries, we develop a hypothesis on the trade-off between AC's inward- and outward-looking drivers. We observe that their impact on the AC of MNC headquarters is diminished for high levels of coordination mechanisms and international exposure. Hence, coordination mechanisms become less effective to absorb subsidiary knowledge as the MNC increases its international footprint. We also conclude that the headquarters of highly internationalized MNCs can regard socialization mechanisms as facilitators of the absorption of knowledge generated by subsidiaries
Explaining Reputation Assessments
Reputation is crucial to enabling human or software agents to select among alternative providers. Although several effective reputation assessment methods exist, they typically distil reputation into a numerical representation, with no accompanying explanation of the rationale behind the assessment. Such explanations would allow users or clients to make a richer assessment of providers, and tailor selection according to their preferences and current context. In this paper, we propose an approach to explain the rationale behind assessments from quantitative reputation models, by generating arguments that are combined to form explanations. Our approach adapts, extends and combines existing approaches for explaining decisions made using multi-attribute decision models in the context of reputation. We present example argument templates, and describe how to select their parameters using explanation algorithms. Our proposal was evaluated by means of a user study, which followed an existing protocol. Our results give evidence that although explanations present a subset of the information of trust scores, they are sufficient to equally evaluate providers recommended based on their trust score. Moreover, when explanation arguments reveal implicit model information, they are less persuasive than scores
Bihamiltonian Cohomologies and Integrable Hierarchies I: A Special Case
We present some general results on properties of the bihamiltonian
cohomologies associated to bihamiltonian structures of hydrodynamic type, and
compute the third cohomology for the bihamiltonian structure of the
dispersionless KdV hierarchy. The result of the computation enables us to prove
the existence of bihamiltonian deformations of the dispersionless KdV hierarchy
starting from any of its infinitesimal deformations.Comment: 43 pages. V2: the accepted version, to appear in Comm. Math. Phy
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