Observations related to the phosphating of aluminium alloy 7075-T6 using a spraying technique

An initial review is made of the effects of changing parameters involved in forming a zinc phosphate coating layer by spraying an aluminium alloy 7075-T6. Various coatings were evaluated by X-ray photoelectron spectroscopy, scanning electron microscopy and adhesion tests. The coating solution reported represents a modification of that previously used for coating the same system by the dipping method (J. Mater. Sci. 31 (1996) 565), but for spraying it was necessary to add the accelerators KClO₃ and NaNO₂ in order to achieve an adequate phosphate layer. For this solution, the favoured coating conditions by spraying corresponded to 1 min at 85 °C. A significant effect on the phosphating process is also indicated for the polishing pre-treatment of the substrate; the coating formed on a surface polished by 1200 grid aluminium oxide sandpaper showed good adhesion to paint, whereas that polished with 1200 grid silicon carbide failed to form an adhesive phosphate coating. In general, conditions for spraying are less easy to control than for dipping, but directions are indicated for obtaining promising coatings by the former approach.     

Daily and momentary mood and stress are associated with binge eating and vomiting in bulimia nervosa patients in the natural environment.

The relation of mood and stress to binge eating and vomiting in the natural environments of patients with bulimia nervosa (BN) was examined using real-time data collection. Women (n = 131; mean age = 25.3 years) with BN carried a palmtop computer for 2 weeks and completed ratings of positive affect (PA), negative affect (NA), anger/hostility (AH), and stress (STRS); they also indicated binge or vomit episodes (BN-events) 6 times each day. Mixed models were used to compare mood and STRS between and within days when BN-events occurred. Between-days analyses indicated that binge and vomit days both showed less PA, higher NA, higher AH, and greater STRS than days with no BN-events. Within-day, decreasing PA, and increasing NA and AH, reliably preceded BN-events. Conversely, PA increased, and NA and AH decreased following BN-events. Demonstration of the temporal sequencing of affect, STRS, and BN-events with a large BN sample may help advance theory and clinical practice, and supports the view that binge and purge events hold negatively reinforcing properties for women with BN. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Making children gesture brings out implicit knowledge and leads to learning.

Speakers routinely gesture with their hands when they talk, and those gestures often convey information not found anywhere in their speech. This information is typically not consciously accessible, yet it provides an early sign that the speaker is ready to learn a particular task (S. Goldin-Meadow, 2003). In this sense, the unwitting gestures that speakers produce reveal their implicit knowledge. But what if a learner was forced to gesture? Would those elicited gestures also reveal implicit knowledge and, in so doing, enhance learning? To address these questions, the authors told children to gesture while explaining their solutions to novel math problems and examined the effect of this manipulation on the expression of implicit knowledge in gesture and on learning. The authors found that, when told to gesture, children who were unable to solve the math problems often added new and correct problem-solving strategies, expressed only in gesture, to their repertoires. The authors also found that when these children were given instruction on the math problems later, they were more likely to succeed on the problems than children told not to gesture. Telling children to gesture thus encourages them to convey previously unexpressed, implicit ideas, which, in turn, makes them receptive to instruction that leads to learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Gender and the sudden infant death syndrome. New Zealand Cot Death Study Group

A nationwide case-control study compared the prevalence and magnitude of risk factors for sudden infant death syndrome (SIDS) in male and female infants. The risk factors of SIDS and their magnitude for males and females are very similar. After adjustment for potential confounders male infants had a 1.42-fold (95% CI = 1.04, 1.94) increased risk of SIDS compared with females. Risk factors identified in most epidemiological studies are not the reason for the increased SIDS mortality seen in male infants.     

Worldwide variations in prevalence of symptoms of allergic rhinoconjunctivitis in children: the International Study of Asthma and Allergies in Childhood (ISAAC)

BACKGROUND: As part of the International Study of Asthma and Allergies in Childhood (ISAAC), prevalence surveys were conducted among representative samples of school children from locations in Europe, Asia, Africa, Australia, North and South America. SUBJECTS: 257,800 children aged 6-7 years from 91 centres in 38 countries, and 463,801 children aged 13-14 years from 155 centres in 56 countries. METHODS: Written symptom questionnaires were translated from English into the local language for self-completion by the 13-14-year-olds and completion by the parents of the 6-7-year-olds. Rhinitis was described as a problem with sneezing, or a runny, or blocked nose when you (your child) DID NOT have a cold or the flu. Additional questions were asked about rhinitis associated with itchy-watery eyes, interference with activities and a history of hay fever ever. RESULTS: The prevalence of rhinitis with itchy-watery eyes ("rhinoconjunctivitis") in the past year varied across centres from 0.8% to 14.9% in the 6-7-year-olds and from 1.4% to 39.7% in the 13-14-year-olds. Within each age group, the global pattern was broadly consistent across each of the symptom categories. In centres of higher prevalence there was great variability in the proportion of rhinoconjunctivitis labelled as hay fever. The lowest prevalences of rhinoconjunctivitis were found in parts of eastern Europe, south and central Asia. High prevalences were reported from centres in several regions. CONCLUSION: These results suggest substantial worldwide variations in the prevalence and labelling of symptoms of allergic rhinoconjunctivitis which require further study. These differences, if real, may offer important clues to environmental influences on allergy.     

CD28 engagement and proinflammatory cytokines contribute to T cell expansion and long-term survival in vivo

To mount a productive response to Ag, CD4+ T cells in mice must divide, differentiate, and survive at least until the Ag has been eliminated. It has been suggested that to accomplish this, T cells must receive two signals, one through their TCRs and a second through CD28. The second signal through CD28 has been thought to fulfill two roles, to stimulate T cell proliferation and to promote T cell survival. In this paper we confirm that CD28 engagement can contribute to vigorous T cell expansion in mice injected with superantigens. However, CD28 engagement does not protect T cells produced during a superantigen-specific proliferative response from undergoing subsequent deletion. Even if CD28 is bound, 4 days after superantigen exposure, the majority of T cells produced in response to superantigen exposure are eliminated in vivo. In contrast, this loss of superantigen-stimulated T cells can be prevented by the inflammatory stimuli created by injection of bacterial LPS. This protection does not require engagement of CD28 by its ligands, B7-1 and B7-2. These data suggest that productive T cell responses in mice involve a number of signals, including those initiated through TCR and CD28, which are primarily involved in the activation and expansion of T cells, and others delivered by proinflammatory cytokines that protect an activated T cell from subsequent deletion.     

Ultrasonographic screening before hospital discharge for deep venous thrombosis after arthroplasty: the post-arthroplasty screening study. A randomized, controlled trial

OBJECTIVE: To relate the histological composition of carotid artery plaques with morphology as evaluated by B-mode ultrasound. DESIGN: Prospective study. MATERIAL AND METHODS: Seventy-eight symptomatic patients underwent carotid endarterectomy after preoperative ultrasound Duplex scanning evaluating plaque morphology. Morphometric analysis of the removed specimen was performed in order to quantify content of lipid, haemorrhage, calcification and fibrous tissue. RESULTS: Echolucent plaques contained more lipid (p = 0.01) and less calcification (p = 0.01) and fibrous tissue (p = 0.03) than echo-rich plaques. Intraplaque haemorrhage was directly related to lipid content (p = 0.004) and inversely related to amount of fibrous tissue in the plaque (p = 0.02). CONCLUSION: The intensity of the reflected B-mode ultrasound signal appears related to the histological composition of the plaque. The association between intraplaque haemorrhage and a high lipid content may support the theory of the lipid-rich plaque being more prone to rupture.     

An attempt to give nursing home residents a voice in the quality improvement process: the challenge of frailty

A model for the development of spatiotemporal receptive fields of simple cells in the visual cortex is proposed. The model is based on the 1990 hypothesis of Saul and Humphrey that the convergence of four types of input onto a cortical cell, viz. non-lagged ON and OFF inputs and lagged ON and OFF inputs, underlies the spatial and temporal structure of the receptive fields. It therefore explains both orientation and direction selectivity of simple cells. The response properties of the four types of input are described by the product of linear spatial and temporal response functions. Extending the 1994 model of one of the authors (K.D. Miller), we describe the development of spatiotemporal receptive fields as a Hebbian learning process taking into account not only spatial but also temporal correlations between the different inputs. We derive the correlation functions that drive the development both for the period before and after eye-opening and demonstrate how the joint development of orientation and direction selectivity can be understood in the framework of correlation-based learning. Our investigation is split into two parts that are presented in two papers. In the first, the model for the response properties and for the development of direction-selective receptive fields is presented. In the second paper we present simulation results that are compared with experimental data, and also provide a first analysis of our model.     

Presence of mu and kappa opioid receptor mRNAs in galanin but not in GnRH neurons in the female rat

Using a combination of radioactive and non-radioactive in situ hybridizations, the expression of mu and kappa opioid receptor mRNA was investigated in neurons in the female rat preoptic nucleus expressing galanin and gonadotropin-releasing hormone (GnRH) mRNA. Numerous cells expressing both mu or kappa and galanin were found in the intermediate and rostral regions of the preoptic area whereas little co-localization was observed at the rostral level. The number of kappa/galanin expressing cells was greater than that of mu/galanin cells. mu/galanin co-localization was observed essentially in the anteroventral preoptic nucleus while neurons expressing kappa/galanin were present in both the anteroventral preoptic nucleus and in the periventricular hypothalamic nucleus. Co-localization of GnRH with mu or kappa could not be detected in the preoptic area. These observations showed that galaninergic neurons but not GnRH neurons of the preoptic area might be directly regulated by endogenous opioid peptides.     

Structural and functional characterisation of two proteolytic fragments of the bacterial protein toxin, pneumolysin

Proteolytic cleavage of the bacterial protein toxin pneumolysin with protease K creates two fragments of 37 and 15 kDa. This paper describes the purification of these two fragments and their subsequent physical and biological characterisation. The larger fragment is directly involved in the cytolytic mechanism of this pore-forming protein, via membrane binding and self-association. The smaller fragment lacks ordered structure or discernible activity.