A new two-stage curing system: Thiol-ene/epoxy homopolymerization using an allyl terminated hyperbranched polyester as reactive modifier

An allyl terminated hyperbranched polyester (HBP) was added to an epoxy formulation containing a trithiol compound to perform a thiol-ene click reaction. By this procedure a flexible thioether network was formed. The photoirradiation of the reactive mixture, which contained a cationic photoinitiator, converted the thioether network in a multifunctional thermal macroinitiator, capable to initiate the cure of the cycloaliphatic epoxy resin(CE) in a second thermal stage. Depending on the proportion of HBP, thermal or photocuring of the epoxy resin took place in different extent, leading to networks with different structures. The photocuring procedure was followed by FTIR and the thermal second stage by DSC. The materials obtained were characterized by DMTA, TGA and SEM. The addition of HBP-Allyl and the trithiol to the formulation allowed increasing the T_g on comparison with the neat epoxy thermoset. The system proposed constitutes a new two-stage dual photo-thermal curing procedure for cycloaliphatic epoxy resins with a thermal latent character.     

Mental health symptoms in youth affected by Hurricane Katrina.

Natural disasters, such as hurricanes, may cause severe psychological impairment in children and adolescents, which may persist in youth who have survived hurricanes, their effects, or both. To better understand the needs of youth in the community after Hurricane Katrina, officials in St. Bernard Parish, LA, commissioned a youth needs assessment survey. The survey assessed how youth were coping approximately 2 years after Hurricane Katrina. The goal was to explore the prevalence and severity of depressive, anxious, and posttraumatic symptoms reported by youth. Based on retrospective reports from 43 youth, the prevalence of children’s mental health symptoms was 44–104% higher in the 2 years after Hurricane Katrina compared to pre-Katrina. The majority of mental health symptoms reported by youth had an onset after the hurricane, for example, 79% reported new onset of mental heath symptoms in the year after Katrina. The vast majority of these children (56%) continued to experience mental health difficulties 2 years after the disaster. Implications regarding post-Katrina mental health needs, service delivery, public response, and collaboration efforts are summarized and directions for future research are proposed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Preferential metabolism of linoleic acid by five-day-old barley shoots

The degradation of exogenous radioactively labeled fatty acids by 5-day-old barley shoots was examined. [1-¹⁴C] Linoleic acid was observed to be degraded 7 times faster than [1-¹⁴C] oleic acid and 5 times faster than [1-¹⁴C] palmitic acid. The pathway of degradation was determined by identifying the water-soluble products and determined to be β-oxidation. During a 15 min incubation, the barley shoots took up 0.91 nmol/g fresh wt of linoleic acid, of which 0.16 nmol/g fresh wt was incorporated into glutamic acid, 0.07 nmol/g fresh wt into succinic acid and 0.002 nmol/g fresh wt into carbohydrates. By 30 min, additional TCA cycle intermediates, especially malic acid, were detected. Palmitic acid and oleic acid were broken down to the same products. The rates of uptake and the distribution of label into lipids were determined. The uptake of label by the tissue was similar for all 3 fatty acid substrates. Label from linoleic, oleic and palmitic acids was found to be incorporated into similar lipids, primarily phosphatidylcholine (PC), and the extent of incorporation was comparable. Although all 3 fatty acid substrates were broken down by β-oxidation, the reason for the more rapid degradation of linoleic acid was not established. It does not appear to be related to uptake of substrate or incorporation of label into lipids.     

Comprehension and production of symbols in infancy: An experimental study.

There is now considerable evidence in support of the Piagetian-Wernerian hypothesis that early language emerges out of a more general symbolic capacity, one that also includes the use of gestural symbolic schemes in play. The present study examined the same hypothesis, but in a situation with more controls over the eliciting conditions for different aspects of early symbolization. The processes studied were word comprehension, word production, and gestural production. Ss were 26 infants tested longitudinally at 13 and 20 mo, responding to the same set of familar objects in realistic vs abstract versions. Word comprehension was unaffected by the abstraction manipulation at either age, but did increase significantly over time. Word production also increased developmentally and interacted significantly with abstraction (with more naming of realistic objects). Gestural production actually decreased over time. The abstractness effect on gesture interacted with age, in that the difference between realistic and abstract objects was much greater at 13 mo. Results are discussed in terms of a "switchover" in the preferred modality for recognizing or categorizing objects in the 2nd yr. Differences in the contextual dependence of gesture and word (i.e., effect of perceptual detail in the object) are also considered. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Graduate training in psychology: The trend in specialization at the master's level.

Should the master's degree be a terminal degree of a steppingstone to the doctorate? The question of specialization at this level also enters the picture. Data from published research of other investigators indicate that "for each field in which the Master's is offered in both 1951-52 and in 1961-62 not only has the percentage of schools offering it sharply decreased but also… the absolute number is less." As compared with 1951, the 1961 figures "show that Masters' in the major fields of psychology are offered in fewer schools today, and a large number offer no Master's at all… . The number and percentages of schools offering no Master's degrees in psychology has more than tripled in the ten-year period." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Variation of Band Gap and Lattice Parameters of β−(AlxGa1−x)2O3 Powder Produced by Solution Combustion Synthesis

Single‐phase monoclinic aluminum–gallium oxide powders, β?(Al_xGa_1?x)₂O₃, have been produced by solution combustion synthesis for Al fraction 0 ≤ x < 0.8. α?(Al_xGa_1?x)₂O₃ is observed for x = 1, with mixed α + β for x = 0.8. The contraction in lattice parameters and increase in band gap with increasing Al concentration were characterized by X‐ray diffraction (XRD) and X‐ray photoelectron spectroscopy (XPS), respectively, and are compared with a first‐principles density‐functional theory calculation. A novel filtering procedure is described to reduce the uncertainty involved in measuring band gap using photoemission, and to remove asymmetry in XPS line shapes caused by differential charging of loose powder. The lattice parameters vary linearly with Al fraction, but exhibit a change in slope at x = 0.5 that is attributed to the difference between aluminum occupying tetrahedral and octahedral sites in the monoclinic lattice. The band gap changes linearly with local stoichiometry, including increasing when aluminum content at the surface is enriched relative to the interior, with a range of over 1.8 eV.     

Maternity leave, women's employment, and marital incompatibility.

This research investigated the relationship between the length of women's maternity leave and marital incompatibility, in the context of other variables including the woman's employment, her dissatisfaction with the division of household labor, and her sense of role overload. Length of leave, work hours, and family salience were associated with several forms of dissatisfaction, which in turn predicted role overload. Role overload predicted increased marital incompatibility for experienced mothers but did not for first-time mothers, for whom discrepancies between preferred and actual child care were more important. Length of maternity leave showed significant interactions with other variables, supporting the hypothesis that a short leave is a risk factor that, when combined with another risk factor, contributes to personal and marital distress. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

STRESS-STRAIN RELATIONS IN CERAMIC MATERIALS*

The electric strain gauge was used to study the deformation of several types of ceramic materials under stress. It was found that they behaved as elastic materials. The hard-fired materials exhibit straight-line deformation to failure while the softer-fired have a proportional elastic limit beyond which the stress-strain curve deviates from a straight line. Data indicate that engineering formulas based on elastic materials may be applied to ceramic materials.     

Infants' meaning-making and the development of mental health problems.

We argue that infant meaning-making processes are a central mechanism governing both typical and pathological outcomes. Infants, as open dynamic systems, must constantly garner information to increase their complexity and coherence. They fulfill this demand by making nonverbal “meaning”—affects, movements, representations—about themselves in relation to the world and themselves into a “biopsychosocial state of consciousness,” which shapes their ongoing engagement with the world. We focus on the operation of the infant–adult communication system, a dyadic, mutually regulated system that scaffolds infants' engagement with the world of people, things, and themselves, and consequently their meaning-making. We argue that infant mental health problems emerge when the meanings infants make in the moment, which increase their complexity and coherence and may be adaptive in the short run, selectively limit their subsequent engagement with the world and, in turn, the growth of their state of consciousness in the long run. When chronic and iterative, these altered meanings can interfere with infants' successful development and heighten their vulnerability to pathological outcomes. Cultural variations in meaning-making and implications for clinical practice are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)