An upper-shelf fracture toughness master curve for ferritic steels

When assessing the resistance of a steel structure to failure under load, fracture toughness is a key input variable. Since it is usually not possible to establish a priori if the anticipated service temperature (or temperatures) is in the fracture mode transition or on the upper shelf, it is useful to know the temperature dependence of fracture toughness in both the transition and on the upper shelf. In the transition, the master curve proposed by Wallin defines both the variation of the median value of fracture toughness with temperature and the scatter of fracture toughness about this median value. However, Wallin's master curve does not quantify fracture toughness on the upper shelf. In this paper we assemble a database of upper shelf fracture toughness data (J_Ic) for ferritic steels. These data demonstrate that the temperature dependence of upper J_Ic is consistent for all ferritic steels contained in the database and has the same form as the temperature dependence of the flow strength anticipated from dislocation mechanics considerations. This similarity between the temperature dependence of flow strength and the temperature dependence of J_Ic is physically expected because both directly depend upon the energy required for dislocation mobility in the ferrite matrix. Both the empirically derived model and the physical basis for the model are described.     

Development of the First Oral Bioprecursors of Bis‐alkylguanidine Antimalarial Drugs

Plasmodium falciparum is responsible of the most severe form of malaria, and new targets and novel chemotherapeutic scaffolds are needed to fight emerging multidrug‐resistant strains of this parasite. Bis‐alkylguanidines have been designed to mimic choline, resulting in the inhibition of plasmodial de novo phosphatidylcholine biosynthesis. Despite potent in vitro antiplasmodial and in vivo antimalarial activities, a major drawback of these compounds for further clinical development is their low oral bioavailability. To solve this issue, various modulations were performed on bis‐alkylguanidines. The introduction of N‐disubstituents on the guanidino motif improved both in vitro and in vivo activities. On the other hand, in vivo pharmacological evaluation in a mouse model showed that the N‐hydroxylated derivatives constitute the first oral bioprecursors in bis‐alkylguanidine series. This study paves the way for bis‐alkylguanidine‐based oral antimalarial agents targeting plasmodial phospholipid metabolism.     

Simplification of a complex microbial antilisterial consortium to evaluate the contribution of its flora in uncooked pressed cheese

A complex microbial consortium derived from raw milk and composed of populations classified in 4 groups (lactic acid bacteria (A), Gram positive catalase positive bacteria (B), Gram negative bacteria (C) and yeasts (D)) can contribute to the inhibition of Listeria monocytogenes in the core of an uncooked pressed cheese. To identify what groups may be involved in the inhibition, the consortium was simplified by successively omitting one group at a time. Pasteurized milk was inoculated with these more or less complex consortia and their effects on L. monocytogenes count, pH, acids and volatile compounds in the core of uncooked pressed cheese were evaluated. The growth of L. monocytogenes was the highest in cheeses prepared with pasteurized milk and only St. thermophilus. Inhibition in other cheeses was expressed by comparison with growth in these ones. All the consortia containing both lactic acid bacteria (group A) and Gram positive catalase positive bacteria (group B)--ABCD, ABD, ABC, AB--were more inhibitory than those containing lactic acid bacteria on its own (A) or associated only with yeasts (AD) or/and Gram negative (ADC). Consortia without lactic acid bacteria were weakly inhibitory or had no effect. Gram positive catalase positive bacteria alone were not inhibitory although most of the species became established in the cheeses. The Lactobacillus population (Lb. casei, Lb. plantarum, Lb. curvatus and Lb. farciminis) was predominant in cheeses (9 log CFU/g) with a higher count than Leuconostoc (7 log CFU/g) and Enterococcus (7 log CFU/g). Lactobacillus counts were negatively correlated with those of L. monocytogenes (r=-0.84 at 18 days) and with the level of D-lactic acid. There was no correlation between L. monocytogenes and Leuconostoc or Enterococcus counts. Complex consortium ABCD and AB not only had a stronger inhibitory power in cheeses than consortium AD, they were also associated with the highest levels of L-lactic and acetic acids. All cheeses inoculated with lactic acid bacteria differed from those without by higher levels of ethyl formiate, pentane and alcohols (2-butanol, 2-pentanol), and lower levels of ketones (2-hexanone, 2,3-butanedione) and aldehydes (2-methyl-butanal). Levels of 2-methyl-butanal, 2-butanol and 2-pentanol were higher in ABCD and AB cheeses than in AD cheeses. Beside their contribution to the inhibition, their effect on cheese flavour must be evaluated.     

Coping With Downsizing: A Comparison of Executive-Level and Middle Managers.

A longitudinal study compared the reactions of executive-level and middle managers prior to a large-scale downsizing, during initial and final phases, and following the downsizing. Compared with executives, middle managers perceived greater job insecurity, were more likely to use escape coping, and reported lower job performance and higher levels of health symptoms. Over time, both executives and middle managers reported a decline in perceived threat of job loss but an increase in sense of powerlessness, a decrease in the use of control-oriented coping strategies, and reduced job performance in the initial phase of downsizing. Although less so, executive-level managers were also adversely affected by the downsizing, suggesting that this group should be included in stress management interventions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Development of a psychosocial program on a dialysis unit.

By actively seeking involvement, psychologists were able to develop an intervention program on a dialysis unit. Significant aspects of the program as well as problems encountered are described, and suggestions are made for the application of this approach to other medical settings. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of pre-press treatments of vegetation on the quality of the extracted leaf protein

The effect of various treatments during processing on the quality of extracted leaf protein concentrates from grass and lucerne has been investigated. There was little difference in the N contents of the heat-coagulated leaf proteins from various extracts. The preparations contained only small amounts of extractable phenolic compounds when polyvinylpyrrolidone (PVP) was present during the extraction procedure. Conversely, all leaf proteins made by processes involving treatment with alkali had a larger phenolic content. Some of the phenolic compounds extracted have been tentatively identified. The amino acid composition and in vitro digestibility, with thioglycollic acid-activated papain, of all preparations were similar. These results are discussed in relation to the known in vivo digestibility of extracted leaf protein concentrates.     

Effects of anxiety on analogical reasoning: A test of three theoretical models.

Three mediational theories of anxiety and performance, namely, J. A. Easterbrook's (see record 1961-03074-001) cue utilization theory, G. Mandler and S. B. Sarason's (see record 1953-02743-001) attentional theory, and M. W. Eysenck's (1979) working memory capacity theory, were compared for their efficacy in explaining anxiety-induced performance decrements on a task of analogical reasoning. 102 undergraduates who varied in their trait and state anxiety levels completed 100 geometric analogies under either relaxed (reassurance, non-time-limited) or stress (ego-threat, time-limited) conditions. Response time and error rate data for 9 levels of task complexity (1-, 2-, and 3-element analogies with 0, 1, or 2 transformations for each element) were analyzed by means of multivariate analysis of variance. Results in the relaxed condition support attentional theory in that more anxious Ss were both slower and less accurate than were less anxious Ss. In the stressed condition, none of the 3 anxiety-performance theories was supported. More anxious Ss were faster but made more errors than did less anxious Ss. Thus, in the stressed condition, performance differences suggested differences in speed–accuracy trade-off strategies rather than differences in processing abilities. The limitations of attentional theory and the need to study the effects of anxiety and time stress on information processing are discussed. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of participant modeling on information acquisition and skill utilization.

Assessed the contribution of active participant modeling in coping skills training by evaluating 2 critical process variables: the retention of information about the threatening events and how to cope with them, and the visceral component of imaginal rehearsal. 38 8–13 yr old children, highly fearful of dentists (the Dental subscale of the Children's Fear Survey Schedule), were shown a videotape of 2 children practicing controlled respiration and imagery techniques while undergoing dental treatment. The participant modeling group was encouraged to practice these as they watched the film, whereas the symbolic modeling group was told that this might help them during their own dental treatment, which immediately followed videotape preparation. Ss who had the active participant instructions obtained more information from the videotape, reported greater reduction in dental anxiety, and showed lower respiratory rates as they watched the videotape. They reported greater use of imagery techniques and enhanced self-control. The degree of disruptiveness was significantly lower during subsequent actual dental treatment in Ss from the active practice group. (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychophysiological treatment of migraine and tension headaches: A 12-month follow-up.

Conducted a 12-mo follow-up of the present authors' (1983) study population of chronic headache sufferers by telephone interviewing 31 chronic migraine and 25 chronic tension headache patients (aged 18–61 yrs) who had been treated with EMG, muscle relaxation, and fingertip temperature training to test a hypothesis of biofeedback placebo effects. A previous 3-mo follow-up had revealed that all treatments had produced significant improvement, and relaxation was not as good as the biofeedback devices for obtaining a reduction in monthly headache hours. At 12-mo follow-up, the 3-mo improvement was sustained overall, but migraineurs as a group appeared to regress slightly, while tension patients improved significantly in the interim. On the basis of a 50% reduction in symptomatology, biofeedback treatment was significantly superior to relaxation for tension headaches, although this had not been true at the 3-mo assessment. Temperature training was at least as effective as EMG for both headache groups. In view of these results, biofeedback treatment is viewed less as placebo administration and more as a secondary reinforcer of a specific but unknown physiological response. (11 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Need for social approval as a predictor of the strategic and outcome aspects of bargaining behaviour in asymmetric power situations: An interactionist approach.

Investigated the effects of need for social approval (NAP) on the outcome (Exp. I) and strategic (Exp. II) aspects of bargaining in 2 mixed-motive nonconstant sum games. An interactionist approach was adopted in that (a) the possible attenuating effects of a contextual variable (differential bargaining power) were examined; and (b) face-to-face open communication was permitted. Exp. I, with 64 male and female undergraduates, shows that low-NAP Ss obtained higher final outcomes than high-NAP Ss only when the former were in the low-power position. Results of Exp. II, with 32 male Ss, support the following conclusions: (a) in the high power position, high-NAP Ss (as opposed to low-NAP Ss) adopt a softer initial bid strategy, exhibit a higher overall level of offers, and reach agreements that yielded them a smaller dyadic profit difference; and (b) in the low-power position, personality differences in NAP do not, as predicted, have a significant effect on strategies employed or final outcomes attained. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)