Aggressive behavior among Israeli elementary school students and associated emotional/behavioral problems and self-control.

This study aimed to identify aggression patterns among students, compare teachers' and students' reports on aggressiveness, and examine whether emotional and behavioral problems and self-control intercorrelate with aggression and can explain it among students. The study investigated 363 students aged 8 to 11 years and their 12 homeroom teachers in two elementary schools in central Israel. As expected, students reported higher verbal aggression than physical without gender differences in the general tendency. Also, students reported a higher rate of others' aggression toward them than their own aggression toward others. Similarities emerged between students' and teachers' reports. Four types of students were classified: the aggressive initiator (proactive), the aggressive responder (reactive), the passive victim, and a neutral type. An important outcome was the significant negative association of aggressiveness with self-control. Students with higher rates of self-control skills presented lower rates of aggressive behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Pre- and post-admission attrition of homeless, mentally ill chemical abusers referred to residential treatment programs

AIMS: To assess the magnitude and psychopathologic predictors of attrition among homeless, mentally ill chemical abusers (MICAs) referred to residential treatment programs in New York City. DESIGN: Homeless, MICAs were randomly referred to a therapeutic community (TC) or community residence (CR) and monitored with regard to pre- and post-admission attrition. SETTINGS: Community based treatment facilities modified to treat both substance abuse and major mental illness. PARTICIPANTS: Homeless individuals with a major mental illness (DSM-III-R) and a history of abusing alcohol or other drugs. MEASUREMENTS: Attrition rates and selected scales of psychopathology. FINDINGS: From an initial pool of 694 treatment candidates, 147 (22%) were rejected for admission at their assigned facility; 247 (36%) failed to show up for treatment; and 212 (31%) dropped out of treatment at some point during the first 12 months. Contrary to expectation, those with severe levels of psychotic ideation, depressive symptoms and hostility were admitted to treatment more frequently and stayed in treatment longer at the TC, a high demand approach, than the CR, a low demand approach. CONCLUSION: Clinicians should consider the TC as a viable treatment option for MICAs.     

Average modelling and simulation of series parallel resonantconverters by PSPICE compatible behavioural dependent sources

A new methodology for developing average models of resonant converters is presented and verified against cycle by cycle simulation, showing excellent agreement. The proposed modelling approach applies the concept of R_ac(t), which represents the instantaneous effective load of the resonant network. The model can be used as it is to run steady-state (DC), large signal (transient) and small signal (AC) simulations     

Behavioural average model of SEPIC converters with coupledinductors

An average model of SEPIC converters with coupled inductors was developed and verified against cycle-by-cycle simulations. The model can be used as is by any modern circuit simulator to run steady state (DC), large signal (transient) and small signal (AC) analyses. The inductors coupling coefficient, incorporated as a parameter in the model, can be varied from zero to almost unity. Zero coupling coefficient represents the case of a SEPIC converter with uncoupled inductors     

HIV infection risks among homeless, mentally ill, chemical misusing men

This study attempts to identify the specific role that each of three conditions afflicting homeless, mentally ill, chemically misusing (HMICM) men plays in exposing these men to the risk of HIV infection. Three hundred and fifteen HMICM men (33 of whom were HIV+) were interviewed on intravenous drug use (IVDU) and sex practices. Two scales of risky IVDU practices and sex conducts were constructed and analyzed in relation to HIV status. The severity of homelessness, mental illness, and chemical misuse, then, were analyzed as possible predictors of risky IVDU and sex practices. Strong correlations were found between IVDU practices and HIV seropositivity, and between risky sex conduct and HIV seropositivity. Serious depression was the strongest predictor of risky IVDU practices. Prolonged homelessness was the condition most associated with risky sexual conduct. This study concludes that HMICM men are at high risk for HIV infection, stemming, predominately, from two conditions: depression, leading to risky IVDU practices, and homelessness, leading to risky sex conduct with two separate types of risky behavior.     

A note on evaluating the fracture energy of thin ceramic layers by cleavage

A new method is suggested aimed at evaluating _IC , the mode I fracture energy of thin brittle layers. The fracture energy is obtained by cleaving a ceramic layer sandwiched between two metallic layers, joined by brazing. The driving force for the cleavage is the mismatch between the thermal expansion coefficients of the ceramic and the metallic layers. The fracture energy is calculated from the strain energy released in the cleaved sandwiched structure. Based on this method, the fracture energy of the ceramic layer can be evaluated if the cleavage temperature is known, either by visual inspection or instrumentation. The method is effective for thin ceramic layers, for the determination of the fracture energy of cleavage planes of single crystal brittle solids (provided the cleavage plane is within the plane of the specimen), and for the interfacial fracture energy of ceramic/ceramic or ceramic/metal joints. In order to verify and calibrate the test method, polycrystalline alumina thin plates were joined by brazing with Ti-6Al-4V alloy using Wesgo Cusil ABA alloy. The appropriate selection of materials and geometry, and some difficulties arising from this method are discussed.     

Optical habitats of ultraphytoplankton groups in the Gulf of Eilat (Aqaba), Northern Red Sea

Solar light penetrates deep into the clear water of oligotrophic oceans and may have both beneficial and destructive effects on marine phytoplankton. In oligotrophic waters worldwide, phytoplankton communities consist mostly of ultraphytoplankton of the groups Synechococcus and Prochlorococcus, which differ in their optical properties and, therefore, are better suited for thriving in different niches along the natural vertical light gradient. In this article, we aim to draw the optical boundaries separating the two populations in order to get a better insight into the light-driven dynamics in ultraphytoplankton-community structure and to predict future trends. We report spectral, photosynthetically active radiation (PAR) and ultraviolet radiation (UVR) penetration through the stratified season along with temporal and vertical distributions of Synechococcus and Prochlorococcus in the Gulf of Eilat (Aqaba). These light-field parameters are used to define the apparent limits of the vertical distribution of Synechococcus and Prochlorococcus throughout the water column. Furthermore, we formulate the necessary empirical algorithms, allowing for characterization of the optical habitats defined in this study by remote-sensed or in situ radiometric measurements.