Suicidal ideation and its recurrence in boys and men from early adolescence to early adulthood: An event history analysis.

Occurrence and recurrences of suicidal ideation (SI) were modeled among boys/men assessed annually from ages 12 to 29 years. Multiple-spell discrete-time event-history analyses permitted (a) determination of whether risk for SI escalates with prior experiences of SI (spell effects), while (b) accounting for changes in risk with time (period effects) and (c) controlling for vulnerability factors. Self-reported SI (presence/absence in past week), depressive symptoms, alcohol/substance use, antisocial behavior, and official arrest records were collected annually from 205 boys recruited on the basis of community risk for delinquency. Parents' self-reported psychopathology and SES were collected in childhood. Period effects supported decreasing risk for SI over time. Spell and time-varying 1-year lagged substance use and depressive symptoms independently predicted increased risk for SI. Models involving SI with intent were explored. Consistent with interpersonal psychological theory, risk for young men's SI increases with past experience of SI, even with key propensities controlled. However, risk also decays over time. Targeting conditions that confer risk for SI is essential. Preventing and delaying SI occurrence and recurrence may represent independent mechanisms by which prevention efforts operate. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Using simulators to model transmitted variability in ICmanufacturing

The authors describe a response surface design methodology based on process and device simulations to estimate device variations due to changes in process input parameters from their designed values. The gradient of the simulated device characteristics is estimated directly and used to compute device sensitivities. This methodology was applied to Stanford's 2-μm CMOS fabrication process. Threshold voltage, subthreshold slope, linear transconductance, and saturation current were picked as the target device characteristics for optimization. Five process parameters were examined: boron concentration in the wafer, phosphorous n-well implant dose, boron threshold adjust dose, gate oxidation temperature, and gate length. The methodology was shown to be successful for the exploration of device characteristic values as a function of process parameters, but success for the transmitted variability, because it depends on derivatives which tend to be less like polynomials than the functions themselves, is more limited. In the absence of a direct assessment of the derivative, response surface models fit to the simulator values can give a very misleading picture of the transmitted variability. Models used were quadratic models for Box-Cox transformed device characteristics     

Deposition of hydrogenated amorphous carbon films from CH4/Ar plasmas: Ar dilution effects

Hydrogenated amorphous carbon (a-C:H) films were deposited, at room temperature, from a CH₄/Ar plasma produced by a radio frequency (r.f.) glow discharge system at 13.56 MHz, and different power values. Two different characterisation techniques, Raman and FTIR spectroscopies, have been used to investigate correlations between deposition conditions and properties of hydrogenated amorphous carbon films. The composition of the initial gaseous mixture and the r.f. power input are shown to affect significantly both mechanical and microstructural properties of deposited films. As the fraction of argon in the feed gas is increased, the deposition rate increases and the deposited film shows a higher friction coefficient, thus suggesting the production of a softer material. On the other hand, Raman measurements suggest the occurrence of a lower degree of structural order in the sp² lattice. Experimental findings are discussed in terms of the different chemical composition of the plasma.     

Retardation of Polymeric Carrier Dissolution by Dispersed Drugs: Factors Influencing the Dissolution of Solid Dispersions Containing Polyethlene Glycols

Molecular weight is an important determinant of plyethylene glycol (PEG) dissolution rate: the rate decreasing as the molecular weight is increased. PEG samples of equivalent nominal. molecular weight had different dissolution properties. Intrinsic viscosity and differential scanning calorimetry suggested that the observed differences my be related to molecular weight variation between samples. The dissolution rate of PEG from solid dispersions is retarded, the effect being dependent on the chemical nature of the drug and its concentration. Phenobarbitone was particularly potent in retarding PEG dissolution. Phenobarbitone dissolution rate was retarded from dispersions of high phenobarbitone content. However drug dissolution from solid dispersions low in phenobarbitone were greater than that of pure phenobarbitone. The low dissolution rates were explained in terms of formation of the 2:1 PEG monomer: phenobarbitone complex during solid dispersion formation. At high PEG weight fractions (i.e. 30:1, 50:1) drug dissolution was carrier controlled and although PEG dissolution was greatly suppressed, it was sufficiently large to transport the drug into solution at a rate greater than that of pure phenobarbitone.     

The statistical analysis of data from small groups.

The authors elaborate the complications and the opportunities inherent in the statistical analysis of small-group data. They begin by discussing nonindependence of group members' scores and then consider standard methods for the analysis of small-group data and determine that these methods do not take into account this nonindependence. A new method is proposed that uses multilevel modeling and allows for negative nonindependence and mutual influence. Finally, the complications of interactions, different group sizes, and differential effects are considered. The authors strongly urge that the analysis model of data from small-group studies should mirror the psychological processes that generate those data. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of parental separation and divorce on very young children.

Data from the National Institute of Child Health and Human Development Study of Early Child Care were analyzed to explore effects of marital separation on children in the first 3 years of life. The sample included 73 never-married mothers and 97 separated mothers; a comparison group of 170 was conditionally randomly selected from the 2-parent families. Children in 2-parent families performed better than children in 1-parent families on assessments of cognitive and social abilities, problem behavior, attachment security, and behavior with mother. However, controlling for mothers' education and family income reduced these differences, and associations with separated-intact marital status were nonsignificant (the effect size was .01). Thus, children's psychological development was not affected by parental separation per se; it was related to mothers' income, education, ethnicity, childrearing beliefs, depressive symptoms, and behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Contact stress distributions in a turbine disc dovetail type joint - a comparison of photoelastic and finite element results

Two dimensional photoelastic frozen stress techniques were used to investigate the stress distributions of an axially loaded dovetail joint as is found in the design of some turbine blade-disc fixings. The internal stress distributions were obtained by the shear difference method and were compared to results obtained by using the finite element method. It was found that steep principal stress gradients were present immediately below the contact surfaces in the zone adjacent to the fillet radius of the dovetail fixing, which could be an important consideration in the fatigue strength of the joint. The finite element model used gave the same trends of stress as the photoelastic model, predicted higher peak principal stresses and did not exhibit the same detailed variations of stress distribution.     

Processing of short‐fiber reinforced polypropylene. I. Influence of processing conditions on the morphology of extruded filaments

An experimental investigation of the processing of glass fiber reinforced polypropylene is presented. Final fiber orientation distribution, fiber distribution in filament sections, rheological properties, final fiber length distribution and surface morphology were analyzed. This analysis was done taking into account the quantity of fibers and their interactions and flow conditions. The final fiber orientation increased when shear rate increased and fiber concentration decreased. Moreover, inhomogeneities in fiber distribution increased as the concentration of fibers decreased. The density profile showed a significant variation with fiber concentration, but it was not dependent on the shear rate applied. The viscosity showed a linear dependence with shear rate. The average fiber length and the breadth of this distribution decreased with the increasing fiber concentration and extrusion rate. The extruded filament surface showed minor roughness when the shear rate increased or when the fiber concentration decreased. The results of this experimental characterization give useful information to determine the influence of the processing variables on the final properties of short‐fiber reinforced polypropylene and constitutes the first part of a more ambitious project that also includes the development of a modeling strategy of the processing behavior for short‐fiber composites.     

Relative contributions of expressive behavior and contextual information to the judgment of the emotional state of another.

Used a technique for assessing the relative impact of facial–gestural expressions, as opposed to contextual information regarding the elicitor and situation, on the judgment of emotion. In Study 1, 28 undergraduates rated videotapes of spontaneous facial–gestural expressions and separately rated the emotionally loaded color slides that elicited those expressions. The source clarities of the expressions and slides were matched using correlation and distance measures, and 18 expressions and 9 slides were selected. In Study 2, 72 undergraduate receivers were shown systematic pairings of these expressions and slides and rated the emotional state of the expresser, who was supposedly watching that slide under public or private situational conditions. Expressions were found to be more important sources for all emotion judgments. For female receivers slides were relatively more important in the public than the private situation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

THE HISTORY OF BREWING IN BURTON UPON TRENT

The growth of the brewing industry in Burton on Trent from the eleventh century in Burton Abbey is traced through the many phases of development to the present day.