2,188 research outputs found

    Perturbative power Q^2-corrections to the structure function g(1)

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    We prove that regulating infrared divergencies generates power (~1/(Q^2)^k) corrections to the spin structure function g_1 at small x and large Q^2. At the same time it leads to the corrections ~(Q^2)^k at small Q^2. We present the explicit series of such terms as well as the formulae for their resummation. These contributions are not included in the standard analysis of the experimental data. We argue that accounting for such terms can sizably change the impact of the other power corrections conventionally attributed to the higher twists.Comment: Theoretical grounds for our approach are considered in much more detailed way than in the previous version; 10 pages, 2 figure

    Cost-effectiveness of HBV and HCV screening strategies:a systematic review of existing modelling techniques

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    Introduction: Studies evaluating the cost-effectiveness of screening for Hepatitis B Virus (HBV) and Hepatitis C Virus (HCV) are generally heterogeneous in terms of risk groups, settings, screening intervention, outcomes and the economic modelling framework. It is therefore difficult to compare cost-effectiveness results between studies. This systematic review aims to summarise and critically assess existing economic models for HBV and HCV in order to identify the main methodological differences in modelling approaches. Methods: A structured search strategy was developed and a systematic review carried out. A critical assessment of the decision-analytic models was carried out according to the guidelines and framework developed for assessment of decision-analytic models in Health Technology Assessment of health care interventions. Results: The overall approach to analysing the cost-effectiveness of screening strategies was found to be broadly consistent for HBV and HCV. However, modelling parameters and related structure differed between models, producing different results. More recent publications performed better against a performance matrix, evaluating model components and methodology. Conclusion: When assessing screening strategies for HBV and HCV infection, the focus should be on more recent studies, which applied the latest treatment regimes, test methods and had better and more complete data on which to base their models. In addition to parameter selection and associated assumptions, careful consideration of dynamic versus static modelling is recommended. Future research may want to focus on these methodological issues. In addition, the ability to evaluate screening strategies for multiple infectious diseases, (HCV and HIV at the same time) might prove important for decision makers

    A stitch in time: Efficient computation of genomic DNA melting bubbles

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    Background: It is of biological interest to make genome-wide predictions of the locations of DNA melting bubbles using statistical mechanics models. Computationally, this poses the challenge that a generic search through all combinations of bubble starts and ends is quadratic. Results: An efficient algorithm is described, which shows that the time complexity of the task is O(NlogN) rather than quadratic. The algorithm exploits that bubble lengths may be limited, but without a prior assumption of a maximal bubble length. No approximations, such as windowing, have been introduced to reduce the time complexity. More than just finding the bubbles, the algorithm produces a stitch profile, which is a probabilistic graphical model of bubbles and helical regions. The algorithm applies a probability peak finding method based on a hierarchical analysis of the energy barriers in the Poland-Scheraga model. Conclusions: Exact and fast computation of genomic stitch profiles is thus feasible. Sequences of several megabases have been computed, only limited by computer memory. Possible applications are the genome-wide comparisons of bubbles with promotors, TSS, viral integration sites, and other melting-related regions.Comment: 16 pages, 10 figure

    Vascular responses of the extremities to transdermal application of vasoactive agents in Caucasian and African descent individuals

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    This is an accepted manuscript of an article published by Springer in European Journal of Applied Physiology on 04/04/2015, available online: https://doi.org/10.1007/s00421-015-3164-2 The accepted version of the publication may differ from the final published version.© 2015, Springer-Verlag Berlin Heidelberg. Purpose: Individuals of African descent (AFD) are more susceptible to non-freezing cold injury than Caucasians (CAU) which may be due, in part, to differences in the control of skin blood flow. We investigated the skin blood flow responses to transdermal application of vasoactive agents. Methods: Twenty-four young males (12 CAU and 12 AFD) undertook three tests in which iontophoresis was used to apply acetylcholine (ACh 1 w/v %), sodium nitroprusside (SNP 0.01 w/v %) and noradrenaline (NA 0.5 mM) to the skin. The skin sites tested were: volar forearm, non-glabrous finger and toe, and glabrous finger (pad) and toe (pad). Results: In response to SNP on the forearm, AFD had less vasodilatation for a given current application than CAU (P = 0.027–0.004). ACh evoked less vasodilatation in AFD for a given application current in the non-glabrous finger and toe compared with CAU (P = 0.043–0.014) with a lower maximum vasodilatation in the non-glabrous finger (median [interquartile], AFD n = 11, 41[234] %, CAU n = 12, 351[451] %, P = 0.011) and non-glabrous toe (median [interquartile], AFD n = 9, 116[318] %, CAU n = 12, 484[720] %, P = 0.018). ACh and SNP did not elicit vasodilatation in the glabrous skin sites of either group. There were no ethnic differences in response to NA. Conclusion: AFD have an attenuated endothelium-dependent vasodilatation in non-glabrous sites of the fingers and toes compared with CAU. This may contribute to lower skin temperature following cold exposure and the increased risk of cold injuries experienced by AFD.Published versio

    International Veterinary Epilepsy Task Force Consensus Proposal: Diagnostic approach to epilepsy in dogs

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    This article outlines the consensus proposal on diagnosis of epilepsy in dogs by the International Veterinary Epilepsy Task Force. The aim of this consensus proposal is to improve consistency in the diagnosis of epilepsy in the clinical and research settings. The diagnostic approach to the patient presenting with a history of suspected epileptic seizures incorporates two fundamental steps: to establish if the events the animal is demonstrating truly represent epileptic seizures and if so, to identify their underlying cause. Differentiation of epileptic seizures from other non-epileptic episodic paroxysmal events can be challenging. Criteria that can be used to make this differentiation are presented in detail and discussed. Criteria for the diagnosis of idiopathic epilepsy (IE) are described in a three-tier system. Tier I confidence level for the diagnosis of IE is based on a history of two or more unprovoked epileptic seizures occurring at least 24 h apart, age at epileptic seizure onset of between six months and six years, unremarkable inter-ictal physical and neurological examination, and no significant abnormalities on minimum data base blood tests and urinalysis. Tier II confidence level for the diagnosis of IE is based on the factors listed in tier I and unremarkable fasting and post-prandial bile acids, magnetic resonance imaging (MRI) of the brain (based on an epilepsy-specific brain MRI protocol) and cerebrospinal fluid (CSF) analysis. Tier III confidence level for the diagnosis of IE is based on the factors listed in tier I and II and identification of electroencephalographic abnormalities characteristic for seizure disorders. The authors recommend performing MRI of the brain and routine CSF analysis, after exclusion of reactive seizures, in dogs with age at epileptic seizure onset 6 years, inter-ictal neurological abnormalities consistent with intracranial neurolocalisation, status epilepticus or cluster seizure at epileptic seizure onset, or a previous presumptive diagnosis of IE and drug-resistance with a single antiepileptic drug titrated to the highest tolerable dose

    Testing the cognitive-behavioural maintenance models across DSM-5 bulimic-type eating disorder diagnostic groups: A multi-centre study

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    The original cognitive-behavioural (CB) model of bulimia nervosa, which provided the basis for the widely used CB therapy, proposed that specific dysfunctional cognitions and behaviours maintain the disorder. However, amongst treatment completers, only 40–50 % have a full and lasting response. The enhanced CB model (CB-E), upon which the enhanced version of the CB treatment was based, extended the original approach by including four additional maintenance factors. This study evaluated and compared both CB models in a large clinical treatment seeking sample (N = 679), applying both DSM-IV and DSM-5 criteria for bulimic-type eating disorders. Application of the DSM-5 criteria reduced the number of cases of DSM-IV bulimic-type eating disorders not otherwise specified to 29.6 %. Structural equation modelling analysis indicated that (a) although both models provided a good fit to the data, the CB-E model accounted for a greater proportion of variance in eating-disordered behaviours than the original one, (b) interpersonal problems, clinical perfectionism and low self-esteem were indirectly associated with dietary restraint through over-evaluation of shape and weight, (c) interpersonal problems and mood intolerance were directly linked to binge eating, whereas restraint only indirectly affected binge eating through mood intolerance, suggesting that factors other than restraint may play a more critical role in the maintenance of binge eating. In terms of strength of the associations, differences across DSM-5 bulimic-type eating disorder diagnostic groups were not observed. The results are discussed with reference to theory and research, including neurobiological findings and recent hypotheses

    Characteristics of Community Mental Health Clinics Associated With Treatment Engagement

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    Objectives: Past literature documents many individual predictors of treatment engagement among mental health clients in community settings, but few studies have examined clinic characteristics that may be associated with treatment engagement. With data from a patient activation and self-management trial, this study examined the variation in demographic and clinic characteristics across community mental health clinics and whether this variation predicted differences in treatment engagement in mental health services.Methods: Chart reviews were conducted for 638 clients of 12 community mental health clinics. Client attendance records were collected for a one-year period to examine engagement (defined as the ratio of kept versus scheduled appointments). Adjusting for client variability, the investigators examined which clinic-level characteristics were associated with treatment engagement.Results: Clinics varied significantly in their clients’ demographic characteristics and engagement in mental health care. Providing case management and offering transportation vouchers or free parking at the clinic were associated with lower engagement. However, offering outreach was associated with greater engagement.Conclusions:The results of this study suggest that certain clinic characteristics are associated with engagement in mental health services. These results demonstrate the difficulties faced by community mental health clinics in reducing no-show rates even in the face of strong efforts to improve engagement

    Parent–Child Cultural Value Gaps and Depressive Symptoms Among Mexican American Youth

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    Cultural value gaps between Mexican American parents and their children are hypothesized to place youth at risk for poor mental health outcomes. While most studies examine these gaps on broad measures of acculturation, the present study examined value gaps in affiliative obedience, a cultural value that has at its core the belief that respect and deference must be shown to parents and adults. The present study hypothesized that adolescents would exhibit greater depressive symptoms when youth demonstrated lower levels of affiliative obedience than their mothers. Moreover, we examined whether gender, nativity status, and age predicted cultural value gaps and moderated the relationship between gaps and depressive symptoms. These questions were evaluated in a school-based sample of 159 Mexican American families whose children were either US born (n = 82) or foreign-born (n = 77). Twenty-five percent of the sample demonstrated a cultural value gap where youth endorsed lower levels of affiliative obedience than their parents, and this group reported the greatest depressive symptoms. Age moderated this relationship, and the greatest association between cultural value gaps and depression was found among the older group of early adolescents

    Ethnic Identity in Context of Ethnic Discrimination: When Does Gender and Other-Group Orientation Increase Risk for Depressive Symptoms for Immigrant-Origin Young Adults?

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    Objectives: Ethnic discrimination increases risk for depressive symptoms, but less is known about factors that influence the impact of this cultural challenge on psychological adjustment for immigrant-origin college students. Sociocultural identity development is especially relevant during emerging adulthood. Studies examining exacerbating or buffering impacts of ethnic identity have yielded mixed results. The current study examines conditions under which one aspect of ethnic identity, affirmation/belonging, moderates the impact of perceived ethnic discrimination stress on depressive symptoms. This was expected to vary by other-group orientation and gender, in accordance with rejection sensitivity theory. Method: A multicultural sample of 290 non-White immigrant-origin emerging adults (aged 18–25) from mixed cultural backgrounds and generational statuses attending a college in the Southeastern United States completed electronic self-report questionnaires. Results: More robust support was provided for social identity theory rather than rejection sensitivity theory: stronger affirmation/belonging was inversely associated with depressive symptoms across the sample, with a notable buffering impact for women. Trend-level results indicated a protective effect for those endorsing stronger affirmation/belonging paired with greater other-group orientation. Additionally, women with weaker affirmation/belonging demonstrated greater increased depressive symptoms compared to men with weaker affirmation/belonging. Conclusions: For this sample, social identity theory was relevant to the impact of affirmation/belonging on the relation between ethnic discrimination and depressive symptoms contingent on other-group orientation and gender. This finding underscores the importance of examining ethnic identity in a nuanced manner. Implications for these results extend to college counseling centers, where inclusion of sociocultural identity in case conceptualization would be useful

    Activation, Self-management, Engagement, and Retention in Behavioral Health Care: A Randomized Clinical Trial of the DECIDE Intervention

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    Importance: Given minority patients’ unequal access to quality care, patient activation and self-management strategies have been suggested as a promising approach to improving mental health care. Objective: To determine whether the DECIDE (Decide the problem; Explore the questions; Closed or open-ended questions; Identify the who, why, or how of the problem; Direct questions to your health care professional; Enjoy a shared solution) intervention, an educational strategy that teaches patients to ask questions and make collaborative decisions with their health care professional, improves patient activation and self-management, as well as engagement and retention in behavioral health care. Design, Setting, and Patients: In this multisite randomized clinical trial performed from February 1, 2009, through October 9, 2011 (date of last follow-up interview), we recruited 647 English- or Spanish-speaking patients 18 to 70 years old from 13 outpatient community mental health clinics across 5 states and 1 US territory. A total of 722 patients were included in analyses of secondary outcomes. Interventions: Three DECIDE training sessions delivered by a care manager vs giving patients a brochure on management of behavioral health. Main Outcomes and Measures: Primary outcomes were patient assessment of activation (Patient Activation Scale) and self-management (Perceived Efficacy in Patient-Physician Interactions). Secondary outcomes included patient engagement (proportion of visits attended of those scheduled) and retention (attending at least 4 visits in the 6 months after the baseline research assessment), collected through medical record review or electronic records. Results: Patients assigned to DECIDE reported significant increases in activation (mean ß?=?1.74, SD?=?0.58; P?=?.003) and self-management (mean ß?=?2.42, SD?=?0.90; P?=?.008) relative to control patients, but there was no evidence of an effect on engagement or retention in care. Conclusions and Relevance: The DECIDE intervention appears to help patients learn to effectively ask questions and participate in decisions about their behavioral health care, but a health care professional component might be needed to augment engagement in care. DECIDE appears to have promise as a strategy for changing the role of minority patients in behavioral health care. Trial Registration: clinicaltrials.gov Identifier: NCT0122632
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