Evidence-based family-school interventions with preschool children.

Fifteen studies of family-school interventions with preschool children conducted between 1980 and 2002, and published in peer-reviewed journals, were reviewed and evaluated according to the criteria developed by the Task Force on Evidence-Based Intervention in School Psychology (Division 16 and Society for the Study of School Psychology Task Force, 2003). Results indicate that family-school interventions with preschool children have taken many forms, have targeted a variety of problems and behaviors, and have generally shown positive effects. Efficacious interventions included parent and teacher training, parent education, and behavioral family therapy. Recommendations for future research include increased methodological rigor, replication and extension of current studies, and the completion of longer-term, follow-up investigations to determine whether gains that are made post-treatment are maintained over time. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Leishmania mexicana: induction of metacyclogenesis by cultivation of promastigotes at acidic pH

Cultivation of recently transformed Leishmania mexicana promastigotes at pH 5.5 in Schneider's Drosophila medium supplemented with 20% fetal calf serum produced a homogeneous stationary phase population morphologically similar to metacyclic forms. The cultured forms developed functional characteristics consistent with being metacyclic: they were resistant to complement-mediated lysis, possessed a discernable surface membrane coat in transmission electron micrographs, and were highly infective to peritoneal macrophages in vitro. In contrast, growth of promastigotes at pH 7.0 produced morphologically mixed populations of stationary phase promastigotes, but including a subpopulation with metacyclic-like morphology. These results provide a method for culturing pure populations of L. mexicana metacyclics and provide evidence that metacyclics are biochemically preadapted for survival at acidic pH as amastigotes in macrophage phagolysosomes.     

Effect of postischaemic hypothermia on the mitochondrial damage induced by ischaemia and reperfusion in the gerbil

In order to test the effect of hypothermia on mitochondrial function damage following cerebral ischaemia/reperfusion, Mongolian gerbils were submitted to 30 min bilateral carotid occlusion and 2 h of reperfusion at 37 degreesC or 30 degreesC. After normothermic (37 degreesC) ischaemia/reperfusion, significant decreases in mitochondrial state 3 (+ADP) oxygen consumption (-42.2%), complex II-III activity in synaptosomes (-31.7%) and complex IV were measured, in both free mitochondria and synaptosomes (-30.3% and -27. 8% respectively). However, following hypothermic (30 degreesC) reperfusion, both respiration rates and all enzyme activities remained at levels not significantly different from those in the sham operated controls.     

Distribution of diethylstilboestrol in pigs

The synthetic growth promoter diethylstilboestrol (DES) administered orally to pigs can be detected by radioimmunoassay (RIA) analysis of kidney, liver, faeces, bile and urine from animals fed continuously to slaughter, but not in muscle, fat or plasma. If treated animals are fed on material not containing DES for 72 h prior to slaughter, then the levels of parent compound and metabolite in all products decrease to become not significantly greater than those in control animals. The gross metabolism of DES in pigs and bovines appears to be similar.     

The fracture of acrylic polymers in water

This paper describes the application of linear elastic fracture mechanics analysis to the fracture of acrylic polymers in water. Three denture base acrylics were studied in addition to Perspex. The effects of strain rate and temperature were investigated using double torsion specimens and three-point bend specimens. It was found for most materials that the fracture toughness was dramatically increased on testing in water compared with testing in air. Crack propagation at fast strain rates was unstable in water and the fracture toughness and flaw size were strain-rate dependent, increasing with decreasing test rate, whilst the un-notched fracture strength decreased with decreasing strain rate. At low strain rates, stable crack propagation was achieved and fracture toughness then decreased with decreasing strain rate. The results are discussed in terms of Williams' model for environmental fracture and the effect water has on the crazing process taking place at the crack tip.     

Radiation-induced damage in GaAs particle detectors

The motivation for investigating the use of GaAs as a material for detecting particles in experiments for high-energy physics (HEP) arose from its perceived resistance to radiation damage. This is a vital requirement for detector materials that are to be used in experiments at future accelerators where the radiation environments would exclude all but the most radiation resistant of detector types     

The inactivation kinetics of H-1 parvovirus by chlorine

A newly isolated enteric virus has recently been found to be associated with large outbreaks of waterborne gastroenteritis. Most commonly referred to as the Norwalk agent, this virus appears to be morphologically and biophysically similar to the parvoviruses. In this study the parvovirus H-1, a putative human virus containing single-stranded DNA, was used as a model virus for chlorine inactivation experiments. The objective of this research was to investigate the kinetics of inactivation of this virus by low levels of free chlorine (0.05–0.20 mgl⁻¹) at pH 7 and at 5, 10, 20 and 30°C.Inactivation occurred in the usual dose-response relationship, that is, increasing the chlorine dose caused an increase in the rate of inactivation. The energy required for the inactivation reaction using 0.05 mgl⁻¹ free chlorine from 5 to 30°C was graphically determined to be 2.4 kcal mol⁻¹. The change in entropy was calculated to be -52.34 entropy units. For disinfection purposes, the time required for 99% inactivation of H-1 parvovirus at pH 7.20°C and a chlorine dose of 0.2 mgl⁻¹ free chlorine was 3.2 min. The parvovirus H-1 appeared to be less resistant to free chlorine than poliovirus type 1 (LSc).