Delamination Fracture Related to Tempering in a High-Strength Low-Alloy Steel

The delamination or splitting of mechanical test specimens of rolled steel plate is a phenomenon that has been studied for many years. In the present study, splitting during fracture of tensile and Charpy V-notch (CVN) test specimens is examined in a high-strength low-alloy plate steel. It is shown that delamination did not occur in test specimens from plate in the as-rolled condition, but was severe in material tempered in the temperature range 500 °C to 650 °C. Minor splitting was seen after heating to 200 °C, 400 °C, and 700 °C. Samples that had been triple quenched and tempered to produce a fine equiaxed grain size also did not exhibit splitting. Microstructural and preferred orientation studies are presented and are discussed as they relate to the splitting phenomenon. It is concluded that the elongated as-rolled grains and grain boundary embrittlement resulting from precipitates (carbides and nitrides) formed during reheating were responsible for the delamination.

House value as an indicator of cumulative wealth is strongly related to morbidity and mortality risk in older people: a census-based cross-sectional and longitudinal study

Background: There has been relatively little research into health inequalities in older populations. This may be partly explained by the difficulty in identifying appropriate indicators of socio-economic status for older people. Ideally, indicators of socio-economic status to be used in studies of health inequalities in older populations should incorporate some measure of life-time socio-economic standing, and house value may fill this role. This study examined whether an indicator of accumulated wealth based on a combination of housing tenure and house value was a strong predictor of ill-health in older populations.
Methods: A total of 191 848 people aged =65 years and not living in communal establishments were identified from the 2001 Northern Ireland Census and followed for 5 years. Self-reported health and mortality risk by housing tenure/house value groupings were examined while controlling for a range of other demographic and socio-economic characteristics.
Results: Housing tenure/house value was highly correlated with other indicators of socio-economic status. Public-sector renters had worse self-reported health and higher mortality rates than owner occupiers but significant gradients were also found between those living in the highest-and lowest-valued owner-occupier properties. The relationship between housing tenure and value was unchanged by adjustment for indicators of social support and quality of the physical environment. Adjustment for limiting long-term illness and self-reported health at baseline narrowed but did not eliminate the health gains associated with living in more expensive housing.
Conclusions: House value of residence is an accessible and powerful indicator of accumulated wealth that is highly correlated with current health status and predictive of future mortality risk in older populations.

Aggressive responses to broadband trills are related to subsequent pairing success in nightingales

In sexually selected signals, distinct components often have specific signal value in mate choice or male-male competition. In songbirds, structural song traits such as trills, that is, a series of repetitive notes, can be important in female choice. However, little is known about their signal value in male-male interactions. Here, we investigated the hypothesis that males assess the competitive abilities of rivals based on the use and performance of rapid broadband trills produced within songs. Using a 2-speaker playback experiment, we exposed territorial male nightingales, Luscinia megarhynchos, that differed in their subsequent pairing success, to a simulated vocal interaction between 2 unfamiliar rivals. The singing of the 2 simulated rivals differed in the number of songs containing rapid broadband trills. Subjects responded significantly more strongly to the loudspeaker that broadcast songs containing such trills than to the loudspeaker that broadcast exclusively songs without such trills. Moreover, responses also depended on the fine structure of trills. Males that became paired later in the season significantly increased their response intensity with increasing trill performance, whereas males that remained unpaired responded in the opposite way and decreased their response intensity with increasing trill performance. These results indicate that rapid broadband trills are a signal of aggression and that the nature of the response in vocal interactions reflects aspects of the challenged male's fitness. © The Author 2008. Published by Oxford University Press on behalf of the International Society for Behavioral Ecology. All rights reserved.


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A potent novel antimicrobial peptide related to caerin 1.12 from the skin secretion of the Australian frog, Litoria aurea

Skin secretions from Australian frogs of the genus Litoria have been extensively studied for many years and are known to contain a large array of antimicrobial peptides that often bear their specific names — caerins (L. caerulea), aureins (L. aurea), citropins (L. citropa) and maculatins (L. genimaculata) — and each group displays distinct primary structural attributes. During a systematic transcriptome cloning study using a cDNA library derived from skin secretion of L. aurea, a series of identical clones were identified that encoded a novel 25-mer antimicrobial peptide that displayed 92% structural identity with caerin 1.12 from L. caerulea, differing in amino acid sequence at only two positions — Arg for Gly at position 7 and Leu amide for Ser amide at the C-terminus. The novel peptide had conserved Pro residues at positions 15 and 19 that flank a flexible hinge region which previous studies have suggested are important for effective orientation of the two alpha-helices within the bacterial membrane resulting in lysis of cells. As the two substitutions in the novel peptide serve to increase both positive charge and hydrophobicity, we synthesised a replicate and determined its minimal inhibitory concentration (MIC) against Gram positive Staphylococcus aureus and Gram negative Escherichia coli. The MICs for these organisms were 3 µM and 4 µM, respectively, indicating a high potency and haemolysis was

An exploration of knowledge and attitudes related to pre-pregnancy care in women with diabetes

Aims: Pre-pregnancy care optimizes pregnancy outcome in women with pre-gestational diabetes, yet most women enter pregnancy unprepared. We sought to determine knowledge and attitudes of women with Type 1 and Type 2 diabetes of childbearing age towards pre-pregnancy care.

Methods: Twenty-four women (18 with Type 1 diabetes and six with Type 2 diabetes) aged 17–40 years took part in one of four focus group sessions: young nulliparous women with Type 1 diabetes (Group A), older nulliparous women with Type 1 diabetes (Group B), parous women with Type 1 diabetes (Group C) and women with Type 2 diabetes of mixed parity (Group D).

Results: Content analysis of transcribed focus groups revealed that, while women were well informed about the need to plan pregnancy, awareness of the rationale for planning was only evident in parous women or those who had actively sought pre-pregnancy advice. Within each group, there was uncertainty about what pre-pregnancy advice entailed. Despite many women reporting positive healthcare experiences, frequently cited barriers to discussing issues around family planning included unsupportive staff, busy clinics and perceived social stereotypes held by health professionals.

Conclusions: Knowledge and attitudes reported in this study highlight the need for women with diabetes, regardless of age, marital status or type of diabetes, to receive guidance about planning pregnancy in a motivating, positive and supportive manner. The important patient viewpoints expressed in this study may help health professionals determine how best to encourage women to avail of pre-pregnancy care