Relativistic Structure of the Deuteron: 1.Electro-disintegration and y-scaling

Realistic solutions of the spinor-spinor Bethe-Salpeter equation for the deuteron with realistic interaction kernel including the exchange of pi, sigma, omega, rho, eta and delta mesons, are used to systematically investigate relativistic effects in inclusive quasi-elastic electron-deuteron scattering within the relativistic impulse approximation. Relativistic y-scaling is considered by generalising the non relativistic scaling function to the relativistic case, and it is shown that y-scaling does occur in the usual relativistic scaling variable resulting from the energy conservation in the instant form of dynamics. The present approach of y-scaling is fully covariant, with the deuteron being described by eight components, viz. the 3S_1^{++}, 3S_1^{--}, 3D_1^{++}, 3D_1^{--}, 3P_1^{+-}, 3P_1^{-+}, 1P_1^{+-}, 1P_1^{-+} waves. It is demonstrated that if the negative relative energy states 1P_1, 3P_1 are disregarded, the concept of covariant momentum distributions N(p_0,p), with p_0=M_D/2-\sqrt{p^2+m^2}, can be introduced, and that calculations of lectro-disintegration cross section in terms of these distributions agree within few percents with the exact calculations which include the 1P_1, 3P_1 states, provided the nucleon three momentum |p|\<= 1 GeV/c; in this momentum range, the asymptotic relativistic scaling function is shown to coincide with the longitudinal covariant momentum distribution.Comment: 32 LaTeX pages, 18 eps-figures. Final version to appear in Phys. Rev.

Mood changes, obstetric experience and alterations in plasma cortisol, beta-endorphin and corticotrophin releasing hormone during pregnancy and the puerperium

The relationships between mood change, obstetric experience and alterations in plasma cortisol, β-endorphin (β-EP) and corticotrophin-releasing hormone (CRH) were examined in a prospective study of 97 primiparous Australian women. Psychological measures were administered between the 28th week of pregnancy and the 3rd postnatal month, including the Profile of Mood States (POMS) and the Montgomery Asberg Depressive Rating Scale (MADRS). Blood samples were collected for cortisol, β-EP and CRH assay on most of these occasions and during labour. Factor analysis was used to identify key subsets of psychological variables for use in the subsequent analyses. 'Mood disturbance' and 'tiredness' factors peaked at 38 weeks' gestation, while 'difficulty falling asleep' was greatest around the time of birth. Cortisol, β-EP and CRH concentrations rose significantly as pregnancy advanced and peaked at birth; plasma CRH correlated with plasma cortisol (r=0.54) and β-EP (r=0.32). Women with the highest 'mood disturbance' and MADRS depression scores at 28 weeks' gestation received significantly more pain relief during labour. Those women whose mood deteriorated from 38 weeks' gestation to postnatal day 2 had larger falls in plasma β-EP after delivery (p13) occured in 5.2% of women and mild postnatal depression in 4.7%. Overall, these data suggest a role for circulating CRH in the regulation of maternal cortisol secretion and significant relationships between maternal postnatal mood states and β-EP and between antenatal mood states and obstetric events. © 1990

Neither the internist nor the Internet: Use of and trust in health information sources by people with schizophrenia

Objective: The aim of this study was to explore health information sources accessed by people with schizophrenia and the level of trust invested in them

Positive and Negative Affect in Parents and adolescents: Gender and assessment method considerations

This study examined adolescents’ self-reports and parents’ reports of adolescents’ positive and negative affect toward their parents, as well as mothers’ and fathers’ self-reports of positive and negative affect toward their adolescents. Based on behavioral observations, adolescent–parent interactions were examined to determine the relation between adolescent–parent behavior, adolescents’ perceptions of parental affect, and parents’ perceptions of adolescent affect. Gender of adolescents, gender of parents, and adolescent gender by parent gender interaction effects were studied as was adolescents’ age. Findings suggest that parent gender (i.e., mothers and fathers) and adolescent gender (i.e., boys and girls) are important considerations when studying affect in parent–adolescent relationships. Age-related differences were not evident. Results are discussed with an eye toward improving the assessment of parent–adolescent affect by using multiple methods of assessment such as direct behavioral observations and multiple informants on questionnaire measures

Early intensive care sedation predicts long-term mortality in ventilated critically ill patients

Rationale: Choice and intensity of early (first 48 h) sedation may affect short- and long-term outcome. Objectives: To investigate the relationships between early sedation and time to extubation, delirium, and hospital and 180-day mortality among ventilated critically ill patients in the intensive care unit (ICU). Methods: Multicenter (25 Australia and New Zealand hospitals) prospective longitudinal (ICU admission to 28 d) cohort study of medical/surgical patients ventilated and sedated 24 hours or more. We assessed administration of sedative agents, ventilation time, sedation depth using Richmond Agitation Sedation Scale (RASS, four hourly), delirium (daily), and hospital and 180-day mortality. We used multivariable Cox regression to quantify relationships between early deep sedation (RASS, -3 to -5) and patients' outcomes. Measurements and Main Results: We studied 251 patients (mean age, 61.7 ± 15.9 yr; mean Acute Physiology and Chronic Health Evaluation [APACHE] II score, 20.8 ± 7.8), with 21.1% (53) hospital and 25.8% (64) 180-day mortality. Over 2,678 study days, we completed 14,736 RASS assessments. Deep sedation occurred in 191 (76.1%) patients within 4 hours of commencing ventilation and in 171 (68%) patients at 48 hours. Delirium occurred in 111 (50.7%) patients with median (interquartile range) duration of 2 (1-4) days. After adjusting for diagnosis, age, sex, APACHE II, operative, elective, hospital type, early use of vasopressors, and dialysis, early deep sedation was an independent predictor of time to extubation (hazard ratio [HR], 0.90; 95% confidence interval [CI], 0.87-0.94; P < 0.001), hospital death (HR, 1.11; 95% CI, 1.02-1.20; P = 0.01), and 180-day mortality (HR, 1.08; 95% CI, 1.01-1.16; P = 0.026) but not delirium occurring after 48 hours (P = 0.19). Conclusions: Early sedation depth independently predicts delayed extubation and increased mortality, making it a potential target for interventional studies