Possibility of determinig the parity of the pentaquark Θ+\Theta^+ from photoproduction near threshold

We discuss the possibility of determining the parity of the $\Theta^+$ baryon from photoproduction $\gamma N\to K\Theta^+$ process near threshold. We utilize the conservation laws of parity and angular momentum for the analysis of angular distributions and spin observables near threshold. Since the discussion is in essence a partial wave analysis of the production mechanism the result should be less dependent on the model parameters. Our analysis shows that the angular distribution and photon polarization asymmetry for the process of neutron target are sensitive to the parity of the $\Theta^+$, but not for the case of proton target. In the case of proton target, the polarization asymmetries of target and recoiled $\Theta^+$ are preferred for parity determination.Comment: 23 pages, 13 figures, extended versio

Predictors of outcome in infant and toddlers functional or behavioral disorders after a brief parent–infant psychotherapy

The efficacy of parent–child psychotherapies is widely recognized today. There are, however, less data on predictive factors for outcome in infants and toddlers and their parents. The aim of this study was to highlight predictive factors for outcome after a brief psychotherapy in a population of 49 infants and toddlers aged 3–30 months presenting functional or behavioral disorders. Two assessments were performed, the first before treatment and the second a month after the end of the therapy. These assessments included an evaluation of the child’s symptoms, and of depressive or anxiety symptoms in the parents. The assessments after therapy show complete or partial improvement in the child’s symptoms for nearly three quarters, and a decrease in the number of anxious and depressive mothers, and also in the number of depressive fathers. Three independent factors appear as predictive of unfavorable outcome for the child: frequency and intensity of behavioral problems and fears, and the absence of the father at more than two-thirds of consultations. The outcome for the mother is associated solely with her anxiety score at the start of the therapy. This study underlines the particular difficulties involved in the treatment of infants and toddlers presenting behavioral disturbances and emotional difficulties, and the value of involving the father in treatment

Evidence For Multiple Retention Mechanisms. Cyclodextrin Stationary Phases For The Gas-solid Chromatographic Separation Of Light Hydrocarbons

Cyclodextrin, bonded to silica gel and used as a gas-solid chromatographic (GSC) stationary phase provides a practical and efficient means for separating a wide variety of volatile C1-C7 hydrocarbons at ambient to elevated temperatures. Conditioning the columns at high temperature (300°C) for several hours increased efficiency and resolution. The adsorption of these light hydrocarbons involves multiple retention mechanismns. For unsaturated hydrocarbons, the cyclodextrin GSC column can act as a polar stationary phase analogous to silica gel. However, for saturated hydrocarbons, it acts as a non-polar phase. Evaluation of the columns and an analogous silica gel column with hydrocarbon standards is reported. Capacity factors and chromatograms are presented for compounds analyzed on these GSC stationary phases. © 1993