Stress correlation between instrumentation and simulation analysis of the die for high pressure die casting

A strain gauge instrumentation trial on a high pressure die casting ‘HPDC’ die was compared to a corresponding simulation model using Magmasoft® casting simulation software at two strain gauge rosette locations. The strains were measured during the casting cycle, from which the von Mises stress was determined and then compared to the simulation model. The von Mises stress from the simulation model correlated well with the findings from the instrumentation trial, showing a difference of 5.5%, ~ 10 MPa for one strain gauge rosette located in an area of low stress gradient. The second rosette was in a region of steep stress gradient, which resulted in a difference of up to 40%, ~40 MPa between the simulation and instrumentation results. Factors such as additional loading from die closure force or metal injection pressure which are not modelled by Magmasoft® were seen to have very little influence on the stress in the die, less than 7%.

Maternal stress and behavior modulate relationships between neonatal stress, attention, and basal cortisol at 8 months in preterm infants

There is evidence that the developmental trajectory of cortisol secretion in preterm infants is altered, with elevated basal cortisol levels observed postnatally through at least 18 months corrected age (CA). This alteration is possibly due to neonatal pain-related stress. High cortisol levels might contribute to greater risk of impaired neurodevelopment. Since maternal factors are important for the regulation of infant stress responses, we investigated relationships between infant (neonatal pain-related stress, attention, cortisol) and maternal (stress, interactive behaviors) factors at age 8 months CA. We found that interactive maternal behaviors buffered the relationship between high neonatal pain-related stress exposure and poorer focused attention in mothers who self-reported low concurrent stress. Furthermore, in preterm infants exposed to high concurrent maternal stress and overwhelming interactive maternal behaviors, higher basal cortisol levels were associated with poor focused attention. Overall, these findings suggest that maternal factors can influence the cognitive resilience at 8 months of preterm infants exposed to early life stress.

Neonatal Pain-Related Stress and NFKBIA Genotype Are Associated with Altered Cortisol Levels in Preterm Boys at School Age

Neonatal pain-related stress is associated with elevated salivary cortisol levels to age 18 months in children born very preterm, compared to full-term, suggesting early programming effects. Importantly, interactions between immune/inflammatory and neuroendocrine systems may underlie programming effects. We examined whether cortisol changes persist to school age, and if common genetic variants in the promoter region of the NFKBIA gene involved in regulation of immune and inflammatory responses, modify the association between early experience and later life stress as indexed by hair cortisol levels, which provide an integrated index of endogenous HPA axis activity. Cortisol was assayed in hair samples from 128 children (83 born preterm =32 weeks gestation and 45 born full-term) without major sensory, motor or cognitive impairments at age 7 years. We found that hair cortisol levels were lower in preterm compared to term-born children. Downregulation of the HPA axis in preterm children without major impairment, seen years after neonatal stress terminated, suggests persistent alteration of stress system programming. Importantly, the etiology was gender-specific such that in preterm boys but not girls, specifically those with the minor allele for NFKBIA rs2233409, lower hair cortisol was associated with greater neonatal pain (number of skin-breaking procedures from birth to term), independent of medical confounders. Moreover, the minor allele (CT or TT) of NFKBIA rs2233409 was associated with higher secretion of inflammatory cytokines, supporting the hypothesis that neonatal pain-related stress may act as a proinflammatory stimulus that induces long-term immune cell activation. These findings are the first evidence that a long-term association between early pain-related stress and cortisol may be mediated by a genetic variants that regulate the activity of NF-?B, suggesting possible involvement of stress/inflammatory mechanisms in HPA programming in boys born very preterm. © 2013 Grunau et al.

The importance of the gestation period for welfare of lambs: Maternal stressors and lamb vigour and wellbeing

The prenatal period is of critical importance in defining how individuals respond to their environment throughout life. Stress experienced by pregnant females has been shown to have detrimental effects on offspring behaviour, health and productivity. The sheep has been used extensively as a model species to inform human studies. However, in the farmed environment, the consequences for the lamb of the imposition of prenatal stresses upon the ewe have received much less attention. The stressors that pregnant ewes are most frequently exposed to include sub-optimal nutrition and those related to housing, husbandry and environment which may be either acute or chronic. A systematic review of the literature was adopted to identify material which had production-relevant maternal stressors and lamb outcomes. The current review focussed upon the lamb up to weaning around the age of 100 days and the results clearly demonstrate that stressors imposed upon the ewe have implications for offspring welfare and performance. Maternal under-nutrition (UN) in the last third of pregnancy consistently impaired lamb birth-weight and subsequent vigour and performance, while earlier UN had a variable effect on performance. Feeding the ewe above requirements did not have positive effects on lamb performance and welfare. Social and husbandry stressors such as transport, shearing, mixing and physiological treatments designed to mimic acute stress which would be considered disadvantageous for the ewe had positive or neutral effects for the lamb, highlighting a potential conflict between the welfare of the ewe and her lamb. This review also identified considerable gaps in knowledge, particularly in respect of the impact of disease upon the ewe during pregnancy and interactions between different stressors and the responses of ewe and lamb.

Board invited review:The importance of the gestation period for welfare of calves: Maternal stressors and difficult births

The prenatal period is of critical importance in defining how individuals respond to their environment throughout life. Stress experienced by pregnant females has been shown to have detrimental effects on offspring biology in humans and a variety of other species. It also is becoming increasingly apparent that prenatal events can have important consequences for the behavior, health, and productivity of offspring in farmed species. Pregnant cattle may experience many potentially important stressors, for instance, relating to their social environment, housing system and physical environment, interactions with humans and husbandry procedures, and their state of health. We examined the available literature to provide a review of the implications of prenatal stress for offspring welfare in cattle. The long-term effects of dystocia on cattle offspring also are reviewed. To ensure a transparent and repeatable selection process, a systematic review approach was adopted. The research literature clearly demonstrates that prenatal stress and difficult births in beef and dairy cattle both have implications for offspring welfare and performance. Common husbandry practices, such as transport, were shown to influence offspring biology and the importance of environmental variables, including thermal stress and drought, also were highlighted. Maternal disease during pregnancy was shown to negatively impact offspring welfare. Moreover, dystocia-affected calves suffer increased mortality and morbidity, decreased transfer of passive immunity, and important physiological and behavioral changes. This review also identified considerable gaps in our knowledge and understanding of the effects of prenatal stress in cattle. © 2012 American Society of Animal Science. All rights reserved.

From stress to distress: Conceptualizing the British family farming patriarchal way of life

‘Rural stress’ and ‘farming stress’ are terms that have become commonly appropriated by British health-based academic disciplines, the medical profession and social support networks, especially since the agricultural ‘crises’ of B.S.E. and Foot and Mouth Disease. Looking beyond the media headlines, it is apparent that the terms in fact are colloquial catch-alls for visible psychological and physiological outcomes shown by individuals. Seldom have the underlying causes and origins of presentable medical outcomes been probed, particularly within the context of the patriarchal and traditionally patrilineal way of life which family forms of farming business activity in Britain encapsulate. Thus, this paper argues that insufficient attention has been paid to the conceptualization of the terms. They have become both over-used and ill-defined in their application to British family farm individuals and their life situations. A conceptual framework is outlined that attempts to shift the stress research agenda into the unilluminated spaces of the family farming ‘way of life’ and focus instead on ‘distress’. Drawing upon theorization from agricultural and feminist geography together with cultural approaches from rural geography, four distinct clusters of distress originate from the thoughts of individuals and the social practices now required to enact patriarchal family farming gender identities. These are explored using case study evidence from ethnographic repeated life history interviews with members of seven farming families in Powys, Mid Wales, an area dominated by family forms of farming business. Future research agendas need to be based firmly on the distressing reality of patriarchal family farming and also be inclusive of those who, having rejected the associated way of life, now lie beyond the farm gate.

Stress processes in caring for an end-of-life family member:Application of a theoretical model

Objectives: Family caregivers play a vital role in maintaining the lives of individuals with advanced illness living in the community. However, the responsibility of caregiving for an end-of-life family member can have profound consequences on the psychological, physical and financial well-being of the caregiver. While the literature has identified caregiver stress or strain as a complex process with multiple contributing factors, few comprehensive studies exist. This study examined a wide range of theory-driven variables contributing to family caregiver stress. Method: Data variables from interviews with primary family caregivers were mapped onto the factors within the Stress Process Model theoretical framework. A hierarchical multiple linear regression analysis was used to determine the strongest predictors of caregiver strain as measured by a validated composite index, the Caregiver Strain Index. Results: The study included 132 family caregivers across south-central/western Ontario, Canada. About half of these caregivers experienced high strain, the extent of which was predicted by lower perceived program accessibility, lower functional social support, greater weekly amount of time caregivers committed to the care recipient, younger caregiver age and poorer caregiver self-perceived health. Conclusion: This study examined the influence of a multitude of factors in the Stress Process Model on family caregiver strain, finding stress to be a multidimensional construct. Perceived program accessibility was the strongest predictor of caregiver strain, more so than intensity of care, highlighting the importance of the availability of community resources to support the family caregiving role.

Oxidative stress in lavage fluid of preterm infants at risk of chronic lung disease

There is evidence that oxidative stress plays a role in the development of chronic lung disease (CLD), with immature lungs being particularly sensitive to the injurious effect of oxygen and mechanical ventilation. We analyzed total ascorbate, urate, and protein carbonyls in 102 bronchoalveolar lavage fluid samples from 38 babies (33 preterm, 24–36 wk gestation; 5 term, 37–39 wk gestation). Preterm babies had significantly decreasing concentrations of ascorbate, urate, and protein carbonyls during the first 9 days of life (days 1–3, 4–6, and 7–9, Kruskal-Wallis ANOVA: P 5 0.016, P , 0.0001, and P 5 0.010, respectively). Preterm babies had significantly higher protein carbonyl concentrations at days 1–3 and 4–6 (P 5 0.005 and P 5 0.044) compared with term babies. Very preterm babies (24–28 wk gestation) had increased concentrations of protein carbonyls at days 4–6 (P 5 0.056) and significantly decreased ascorbate concentrations at days 4–6 (P 5 0.004) compared with preterm babies (29–36 wk gestation). Urate concentrations were significantly elevated at days 1–3 (P 5 0.023) in preterm babies who subsequently developed CLD. This study has shown the presence of oxidative stress in the lungs of preterm babies during ventilation, especially in those who subsequently developed CLD.

Perceptions of stressful life events in Northern Irish school children: a longitudinal study.

Adults’ perceptions of stressful life events have been acknowledged as important moderators of the stress adjustment relationship. Until recently, however, there has been a lack of research on children's perceptions of negative life events. This study assesses children's own perceptions of the stressfulness of negative familial, academic and social events as well as events related to the political conflict in Northern Ireland. Method: Developmental changes in children's perceptions of events are traced over time. One hundred and sixty 8-year-old children completed a self-report measure of the perceived stressfulness of a range of negative life events. The sample was drawn from schools in the Greater Belfast area to include children of both genders, primary religious affiliations in Northern Ireland (i.e., Protestant and Roman Catholic) and of varying socio-economic status. Three years later, 113 of these children, then aged 11, were traced through the school system and completed the same measure. Results: Children's perceptions of stressful events are related to a host of social factors. Girls viewed many negative events as more stressful than their male counterparts. Roman Catholic and Protestant children differed in their perceptions of conflict-related events. Perceptions of various types of negative experiences were differentially related to socio-economic status and age. Conclusion: Personal, social and situational factors differentially determine children's perceptions of negative life experiences.

Determinants of Child-Parent Agreement in Quality-of-Life Reports: A European Study of Children With Cerebral Palsy

OBJECTIVES: The differences between child self-reports and parent proxy reports of quality of life in a large population of children with cerebral palsy were studied. We examined whether child characteristics, severity of impairment, socioeconomic factors, and parental stress were associated with parent proxy reports being respectively higher or lower than child self-reports of quality of life. METHODS. This study was conducted in 2004–2005 and assessed child quality of life (using the Kidscreen questionnaire, 10 domains, each scored 0–100) through self-reports and parent proxy reports of 500 children aged 8 to 12 years who had cerebral palsy and were living in 7 countries in Europe. RESULTS: The mean child-reported scores of quality of life were significantly higher than the parent proxy reports in 8 domains, significantly lower for the finances domain, and similar for the emotions domain. The average frequency of disagreement (child-parent difference greater than half an SD of child scores) over all domains was 64%, with parents rating their child’s quality of life lower than the children themselves in 29% to 57% of child-parent pairs. We found that high levels of stress in parenting negatively influenced parents’ perception of their child’s quality of life, whereas the main factor explaining parents’ ratings of children’s quality of life higher than the children themselves is self-reported severe child pain. CONCLUSIONS: This study shows that the factors associated with disagreement are different according to the direction of disagreement. In particular, parental wellbeing and child pain should be taken into account in the interpretation of parent proxy reports, especially when no child self-report of quality of life is available. In the latter cases, it may be advisable to obtain additional proxy reports (from caregivers, teachers, or clinicians) to obtain complementary information on the child’s quality of life.

Parent-Reported Quality of Life of Children With Cerebral Palsy in Europe

OBJECTIVE. The goal was to determine whether the type and severity of the child's impairments and the family's psychosocial, social, and economic characteristics influence parent-reported child quality of life across the spectrum of severity of cerebral palsy.

METHODS. Our population-based, cross-sectional survey conducted in 2004 to 2005 involved 818 children with cerebral palsy, 8 to 12 years of age, from 7 countries (9 regions) in Europe. Child quality of life was assessed through parent reports by using the Kidscreen questionnaire, and data were analyzed separately for each of its 10 domains.

RESULTS. The parental response rates were >93% for all domains except one. Gross motor function and IQ level were found to be associated independently with quality of life in most domains. However, greater severity of impairment was not always associated with poorer quality of life; in the moods and emotions, self-perception, social acceptance, and school environment domains, less severely impaired children were more likely to have poor quality of life. Pain was associated with poor quality of life in the physical and psychological well-being and self-perception domains. Parents with higher levels of stress were more likely to report poor quality of life in all domains, which suggests that factors other than the severity of the child's impairment may influence the way in which parents report quality of life.

CONCLUSIONS. The parent-reported quality of life for children with cerebral palsy is associated strongly with impairment. However, depending on the areas of life, the most severely impaired children (in terms of motor functioning or intellectual ability) do not always have the poorest quality of life.

Adapting musicology’s use of affect theories to contemporary theatre-making: directing Martin Crimp’s Attempts on Her Life

Adopting and adapting musicology’s use of affect theories, specifically Jeremy Gilbert’s idea of an ‘affective analysis’ and David Epstein’s idea of ‘shaping affect’, this article looks at Martin Crimp’s Attempts on Her Life from a practitioner’s perspective. It investigates the challenges and benefits of adopting an ‘affective approach’ to directing recent theatre texts which stress the musicality and corporeality of language along with, and at times above, their signifying roles. Rather than locating Aristotelian dramatic climaxes based on narratological or characterological progression, an affective approach seeks to identify moments of affective intensity, which produce a different sort of impact by working on a ‘body-first’ methodology rather than the directly cerebral. That this embodied impact is not ultimately meaningless is one of affect theories most vital assertions. This approach has resonance in terms of how directors, performers and critics/theorists approach work of this type.