49 research outputs found

    Dissipative dynamics of vortex lines in superfluid 4^{4}He

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    We propose a Hamiltonian model that describes the interaction between a vortex line in superfluid 4^{4}He and the gas of elementary excitations. An equation of irreversible motion for the density operator of the vortex, regarded as a macroscopic quantum particle with a finite mass, is derived in the frame of Generalized Master Equations. This enables us to cast the effect of the coupling as a drag force with one reactive and one dissipative component, in agreement with the assumption of the phenomenological theories of vortex mutual friction in the two fluid model.Comment: 16 pages, no figures, to be published in PR

    On the static solutions in gravity with massive scalar field in three dimensions

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    We investigate circularly symmetric static solutions in three-dimensional gravity with a minimally coupled massive scalar field. We integrate numerically the field equations assuming asymptotic flatness, where black holes do not exist and a naked singularity is present. We also give a brief review on the massless cases with cosmological constant.Comment: 11 pages, LaTeX, 1 Postscript figure. Some changes were don

    Influence of childhood abuse and neglect subtypes on late-life suicide risk beyond depression.

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    The association of childhood maltreatment and suicide has been extensively examined within the population. Depression figures as a main cause for the elevated suicide rate in advanced ages and is often related to childhood maltreatment. The purpose of the present study was to examine the relationship between childhood maltreatment subtypes and suicide risk, testing geriatric depression as a moderator. This is a cross-sectional study looking at a sample of 449 individuals 60 year s old or older from the Multidimensional Study of the Elderly of Porto Alegre Family Health Strategy, Brazil (EMI-SUS/POA). Childhood maltreatment (Childhood Trauma Questionnaire), geriatric depressive symptoms (Geriatric Depression Scale), and suicide risk (Mini International Neuropsychiatric Interview) were assessed. The subtypes of childhood abuse and neglect were significantly associated with suicide risk. In the multivariate analysis, controlling for age, gender, income, marital status, ethnicity, smoking, and geriatric depression symptoms, all trauma subtypes remained associated with suicide risk with the exception of physical neglect (EA = 3.65; PA = 3.16; SA = 5.1; EN = 2.43; PN = 1.76). The present study showed that childhood maltreatment subtypes predicted suicide risk, and geriatric depression does not directly mediate this relation

    Assembling a consensus on actinic cheilitis: A Delphi study

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    Aims To discuss the terminology to define and classify actinic cheilitis (AC) and to build a consensus on the diagnostic and therapeutic approaches to AC. Methods Two-round Delphi study using a questionnaire including 34 closed sentences (9 on terminology and taxonomy, 5 on potential for malignant transformation, 12 on diagnostic aspects, 8 on treatment) and 8 open questions. Experts' agreement was rated using a Likert scale (1-7). Results A consensus was reached on 24 out 34 statements (73.5%) and on 5 out of 8 (62.5%) close-ended questions. The response rate was identical in both rounds (attrition of 0%). AC is the term with the highest agreement (median of 7 (strongly agree; IQR: 6-7)) and the lowest dispersion (VC = 21.33). 'Potentially malignant disorder' was the preferred classification group for AC (median of 7) and 85.6% of participants showing some level of agreement (CV < 50). Experts (66.75%) consider AC a clinical term (median: 7; IQR: 4-7) and believe definitive diagnosis can be made clinically (median: 6; IQR: 5-7), particularly by inspection and palpation (median: 5; IQR: 4-6). Histopathological confirmation is mandatory for the management of AC (median: 5; IQR: 2.5-7), even for homogeneous lesions (median: 5; IQR: 3.5-6). Consensus was reached on all treatment statements (VC < 50). Conclusions AC is a potentially malignant disorder with a significant lack of agreement on diagnostic criteria, procedures, biopsy indications and the importance of techniques to assist in biopsy. A consensus was reached on nomenclature and management of this disorder
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