3,866 research outputs found
An atlas of line profile studies for SU UMa type cataclysmic variables
We present H-alpha line-profile analyses for the seven SU UMa type dwarf
novae AK Cnc, WX Cet, AQ Eri, VW Hyi, RZ Leo, TU Men, and HS Vir. All data sets
are treated in the same manner, applying a sequence of techniques for each
system. The basic ingredients of this sequence are the diagnostic diagram to
determine the zero point of the orbital phase, and Doppler tomography to
visualise the emission distribution. We furthermore introduce a new qualitative
way of to evaluate the Doppler fit, by comparing the line profile of the
reconstructed with the original spectrum in the form of the V/R plot. We
present the results of the analysis in the compact form of an atlas, allowing a
direct comparison of the emission distribution in our targets. Although most of
the data sets were not taken with the intention of a line-profile analysis, we
obtain significant results and are able to indicate the type of the additional
emission in these systems. Our objects should have in principle very similar
physical properties, i.e. they cover only a small range in orbital periods,
mass ratios, and mass-transfer rates. Nevertheless, we find a large variety of
phenomena both with respect to the individual systems and also within
individual data sets of the same object. This includes `canonical' additional
emission components from the secondary star and the bright spot, but also
emission from the leading side of the accretion disc.Comment: 20 pages, 25 figures, accepted for publication in A&A, figures have
been diminished in size and qualit
Acute myocardial infarction in the puerperium. A case report
Acute myocardial infarction is a rare event in the puerperium that can have life-threatening consequences if not diagnosed early. Spontaneous coronary artery dissection is the most frequent causative mechanism in the period immediately after labor. This article reports the case of a 38-year-old woman with acute myocardial infarction due to spontaneous coronary artery dissection on the 7th day after delivery. The authors review this entity and also discuss the prognosis and future management of this patient
Acceleration-Enlarged Symmetries in Nonrelativistic Space-Time with a Cosmological Constant
By considering the nonrelativistic limit of de-Sitter geometry one obtains
the nonrelativistic space-time with a cosmological constant and Newton-Hooke
(NH) symmetries. We show that the NH symmetry algebra can be enlarged by the
addition of the constant acceleration generators and endowed with central
extensions (one in any dimension (D) and three in D=(2+1)). We present a
classical Lagrangian and Hamiltonian framework for constructing models
quasi-invariant under enlarged NH symmetries which depend on three parameters
described by three nonvanishing central charges. The Hamiltonian dynamics then
splits into external and internal sectors with new non-commutative structures
of external and internal phase spaces. We show that in the limit of vanishing
cosmological constant the system reduces to the one presented in [1] which
possesses accelaration-enlarged Galilean symmetries.Comment: 13 pages; small changes like a couple of footnotes et
Validation of the Portuguese version of impulsive-premeditated aggression scale in an inmate population
Aggression is one of the core symptoms of antisocial personality disorder (ASPD) with therapeutic and prognostic relevance. ASPD is highly prevalent among inmates, being responsible for adverse events and elevated direct and indirect economic costs for the criminal justice system. The Impulsive/Premeditated Aggression Scale (IPAS) is a self-report instrument that characterizes aggression as either predominately impulsive or premeditated. This study aims to determine the validity and reliability of the IPAS in a sample of Portuguese inmates. A total of 240 inmates were included in the study. A principal component factor analysis was performed so as to obtain the construct validity of the IPAS impulsive aggression (IA) and premeditated aggression (PM) subscales; internal consistency was determined by Cronbach's alpha coefficient; convergent and divergent validity of the subscales were determined analyzing correlations with the Barratt Impulsiveness scale, 11th version (BIS-11), and the Psychopathic Checklist Revised (PCL-R). The rotated matrix with two factors accounted for 49.9% of total variance. IA subscale had 11 items and PM subscale had 10 items. The IA and PM subscales had a good Cronbach's alpha values of 0.89 and 0.88, respectively. The IA subscale is correlated with BIS-11 attentional, motor, and non-planning impulsiveness dimensions (p < 0.05). The PM subscale is correlated with BIS-11 attentional, motor impulsiveness dimensions (p < 0.05). The PM subscale is correlated with PCL-R interpersonal, lifestyle, and antisocial dimensions (p < 0.05). The IA subscale is not correlated with PCL-R. The Portuguese translated version of IPAS has adequate psychometric properties, allowing the measurement of impulsive and premeditated dimensions of aggression
Stress appraisal, coping, and work engagement among police recruits: an exploratory study.
This study investigated the influence of stress appraisal and coping on work engagement levels (Absorption, Vigour, and Dedication) of police recruits. Participants were 387 men, ages 20 to 33 yr. (M = 24.1, SD = 2.4), in their last month of academy training before becoming police officers. Partially in support of predictions, work engagement was associated with Stressor control perceived, but not Stress intensity experienced over a self-selected stressor. Although the three dimensions of work engagement were explained by Stressor control and coping, Absorption was the dimension better explained by these variables. Police recruits reporting higher Absorption, Vigour, and Dedication reported using more Active coping and less Behavioural disengagement. Results showed that stress appraisal and coping are important variables influencing work engagement among police recruits. Findings suggested that future applied interventions fostering work engagement among police recruits should reinforce perceptions of control over a stressor as well as Active coping strategies
Relationship between optimism, disease variables, and health perception and quality of life in individuals with epilepsy.
Epilepsy Behav. 2007 Aug;11(1):33-8. Epub 2007 May 29.
Relationship between optimism, disease variables, and health perception and quality of life in individuals with epilepsy.
Pais-Ribeiro J, da Silva AM, Meneses RF, Falco C.
Faculdade de Psicologia e de Ciências da Educação, Universidade do Porto, Rua Dr. Manuel Pereira da Silva, 4200-392 Porto, Portugal. [email protected]
Abstract
Epilepsy is a relatively frequent chronic condition with an important impact on the health perception and quality of life (QOL) of patients. The aim of the present study was to identify variables related to health status perception and QOL in persons with epilepsy. Participants were 200 persons with epilepsy, 53.5% of whom were males. The mean age was 39.6; 95% had seizures, and 99% were taking antiepileptic medication. The self-report questionnaire administered assessed four types of variables: demographic, disease, epilepsy-specific optimistic attitude, and outcome variables. Results demonstrated that an optimistic orientation is related to better perception of physical and mental health status and better perception of QOL. The variables that best predict positive outcomes are optimistic orientation, perception of cognitive functioning, and perception of seizure control. These results question the importance attributed to seizure characteristics for everyday functioning and everyday life of individuals with epilepsy, and stress the importance of facilitating an epilepsy-specific optimistic orientation.
PMID: 17537679 [PubMed - indexed for MEDLIN
High-risk features and predictors of unexplained syncope in the young SCD-SOS cohort
Introduction: The Sudden Cardiac Death-Screening of Risk FactOrS survey included a 12-lead ECG plus a digital-based questionnaire and aimed to screen for warning signs of diseases that may course with sudden cardiac death in children and young adults. We aimed to estimate the prevalence of unexplained syncope (US) and characterize its high-risk features and predictors in this cohort. //
Methods &Results: We determined the most probable etiology of transient loss of consciousness (TLOC) episodes based on clinical criteria. US was an exclusion diagnosis and we analyzed its potential clinical and ECG predictors. Among 11,878 individuals, with a mean age of 21±6 (range 6-40) years-old, the cumulative incidence of TLOC was 26.5%, 76.2% corresponding to females. Reflex syncope was present in 66.4%, orthostatic hypotension in 8.2% and 14.8% of the individuals had US. Unexplained syncope was independently associated with age <18years-old (OR 1.695; 95%CI 1.26-2.29,p=0.001), male gender (OR 1.642; 95%CI 1.22-2.22,p=0.001), participation in competitive sports (OR 1.644;95%CI 1.01-2.66,p=0.043), syncope during exertion and/or palpitations preceding syncope (OR 2.556; 95%CI 1.92-3.40,p<0.001), syncope after exertion (OR 2.662; 95%CI 1.73-4.10,p<0.001), fever context (OR 9.606; 95%CI 4.13-22.34,p<0.001), isolated previous syncopal episode (OR 2.780; 95%CI 0.2.06-3.75,p<0.001) and history of palpitations requiring medical care (OR 1.945; 95%CI 1.14-3.31,p=0.014). We found no ECG predictors of US in this population. //
Conclusions: The cumulative incidence of TLOC in children and young adults is high and remains unexplained in an important proportion of individuals. We identified eight clinical characteristics that may be useful for the risk stratification of individuals evaluated in a non-acute setting
Refining the scalar and tensor contributions in decays
In this article we analyze the contribution from intermediate spin-0 and
spin-2 resonances to the decay by means of a chiral
invariant Lagrangian incorporating these mesons. In particular, we study the
corresponding axial-vector form-factors. The advantage of this procedure with
respect to previous analyses is that it incorporates chiral (and isospin)
invariance and, hence, the partial conservation of the axial-vector current.
This ensures the recovery of the right low-energy limit, described by chiral
perturbation theory, and the transversality of the current in the chiral limit
at all energies. Furthermore, the meson form-factors are further improved by
requiring appropriate QCD high-energy conditions. We end up with a brief
discussion on its implementation in the Tauola Monte Carlo and the prospects
for future analyses of Belle's data.Comment: 32 pages, 13 figures. Extended discussion on the numerical importance
of the tensor and scalar resonances and the parametrization of the scalar
propagator. Version published in JHE
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