Atomic-scale Studies of Uranium Oxidation and Corrosion by Water Vapour.

Understanding the corrosion of uranium is important for its safe, long-term storage. Uranium metal corrodes rapidly in air, but the exact mechanism remains subject to debate. Atom Probe Tomography was used to investigate the surface microstructure of metallic depleted uranium specimens following polishing and exposure to moist air. A complex, corrugated metal-oxide interface was observed, with approximately 60 at.% oxygen content within the oxide. Interestingly, a very thin (~5 nm) interfacial layer of uranium hydride was observed at the oxide-metal interface. Exposure to deuterated water vapour produced an equivalent deuteride signal at the metal-oxide interface, confirming the hydride as originating via the water vapour oxidation mechanism. Hydroxide ions were detected uniformly throughout the oxide, yet showed reduced prominence at the metal interface. These results support a proposed mechanism for the oxidation of uranium in water vapour environments where the transport of hydroxyl species and the formation of hydride are key to understanding the observed behaviour.

Maternal pregnancy weight gain and cord blood iron status are associated with eosinophilia in infancy.

OBJECTIVE: Allergic disease is multifactorial in origin. Because iron nutrition affects immune responses and maternal pregnancy weight gain impairs fetal iron delivery while increasing fetal demands for growth, the study examined maternal pregnancy weight gain, newborn iron status and an index of atopic disease, infant eosinophilia. STUDY DESIGN: Within a larger prospective study of healthy newborns at risk for developing iron deficiency anemia, umbilical cord iron indicators were compared to infant eosinophil counts. RESULT: Infants who developed eosinophilia exhibited higher cord reticulocyte-enriched zinc protoporphyrin/heme ratio, P<0.05 and fewer cord ferritin values in the highest (best) quartile, P<0.05. If cord ferritin was in the upper three quartiles, the negative predictive value for infant eosinophilia was 90%. High maternal pregnancy weight gain predicted infant eosinophil counts, P<0.04, and contributed to cord ferritin predicting eosinophilia, P<0.003. CONCLUSION: Poor fetal iron status may be an additional risk factor for infant eosinophilia.

Sleep quality following hematopoietic stem cell transplantation: longitudinal trajectories and biobehavioral correlates.

The present study examined changes in sleep quality following hematopoietic stem cell transplantation (HSCT) and investigated associations with biobehavioral factors. Individuals undergoing HSCT for hematologic malignancies (N=228) completed measures of sleep quality and psychological symptoms pre-transplant and 1, 3, 6 and 12 months post transplant. Circulating inflammatory cytokines (IL-6, TNF-α) were also assessed. Sleep quality was poorest at 1 month post transplant, improving and remaining relatively stable after 3 months post transplant. However, approximately half of participants continued to experience significant sleep disturbance at 6 and 12 months post transplant. Mixed-effects linear regression models indicated that depression and anxiety were associated with poorer sleep quality, while psychological well-being was associated with better sleep. Higher circulating levels of IL-6 were also linked with poorer sleep. Subject-level fixed effects models demonstrated that among individual participants, changes in depression, anxiety and psychological well-being were associated with corresponding changes in sleep after covarying for the effects of time since transplant. Sleep disturbance was most severe when depression and anxiety were greatest and psychological well-being was lowest. Findings indicate that sleep disturbance is a persistent problem during the year following HSCT. Patients experiencing depression or anxiety and those with elevated inflammation may be at particular risk for poor sleep.

Neonatal iron status is impaired by maternal obesity and excessive weight gain during pregnancy.

OBJECTIVE: Maternal iron needs increase sixfold during pregnancy, but obesity interferes with iron absorption. We hypothesized that maternal obesity impairs fetal iron status. STUDY DESIGN: Three hundred and sixteen newborns with risk factors for infantile iron deficiency anemia (IDA) were studied to examine obesity during pregnancy and neonatal iron status. Erythrocyte iron was assessed by cord blood hemoglobin (Hb), zinc protoporphyrin/heme (ZnPP/H) and reticulocyte-ZnPP/H, and storage iron by serum ferritin. RESULT: Women with body mass index (BMI) ⩾ 30 kg m(-)(2), as compared with non-obese women, delivered larger offspring with higher reticulocyte-ZnPP/H and lower serum ferritin concentrations (P<0.05 for both). With increasing BMI, the estimated body iron was relatively lower (mg kg(-)(1)) and the ratio of total Hb-bound iron (mg) per total body iron (mg) increased. Maternal diabetes compromised infant iron status, but multivariate analysis demonstrated that obesity was an independent predictor. CONCLUSION: Obesity during pregnancy and excessive weight gain are independent risk factors for iron deficiency in the newborn.

Interleukin-8 and interleukin-10, brain volume and microstructure, and the influence of calorie restriction in old rhesus macaques.

Higher systemic levels of the proinflammatory cytokine interleukin-6 (IL-6) were found to be associated with lower gray matter volume and tissue density in old rhesus macaques. This association between IL-6, and these brain indices were attenuated by long-term 30 % calorie restriction (CR). To extend these findings, the current analysis determined if a CR diet in 27 aged rhesus monkeys compared to 17 normally fed controls reduced circulating levels of another proinflammatory cytokine, interleukin-8 (IL-8), and raised levels of anti-inflammatory interleukin-10 (IL-10). Further, these cytokines were regressed onto imaged brain volume and microstructure using voxel-wise regression analyses. CR significantly lowered IL-8 and raised IL-10 levels. Across the two dietary conditions, higher IL-8 predicted smaller gray matter volumes in bilateral hippocampus. Higher IL-10 was associated with more white matter volume in visual areas and tracts. Consuming a CR diet reduced the association between systemic IL-8 and hippocampal volumes. Conversely, CR strengthened associations between IL-10 and microstructural tissue density in the prefrontal cortex and other areas, particularly in a region of dorsal prefrontal cortex, which concurred with our prior findings for IL-6. Consumption of a CR diet lowered proinflammatory and increased anti-inflammatory cytokine concentrations, which lessened the statistical association between systemic inflammation and the age-related alterations in important brain regions, including the hippocampus.

Inflammatory vulnerability associated with the rh5-HTTLPR genotype in juvenile rhesus monkeys.

Individual variation in serotonergic function is associated with reactivity, risk for affective disorders, as well as an altered response to disease. Our study used a nonhuman primate model to further investigate whether a functional polymorphism in the promoter region for the serotonin transporter gene helps to explain differences in proinflammatory responses. Homology between the human and rhesus monkey polymorphisms provided the opportunity to determine how this genetic variation influences the relationship between a psychosocial stressor and immune responsiveness. Leukocyte numbers in blood and interleukin-6 (IL-6) responses are sensitive to stressful challenges and are indicative of immune status. The neutrophil-to-lymphocyte ratio and cellular IL-6 responses to in vitro lipopolysaccharide stimulation were assessed in 27 juvenile male rhesus monkeys while housed in stable social groups (NLL = 16, NS = 11) and also in 18 animals after relocation to novel housing (NLL = 13, NS = 5). Short allele monkeys had significantly higher neutrophil-to-lymphocyte ratios than homozygous Long allele carriers at baseline [t(25) = 2.18, P = 0.02], indicative of an aroused state even in the absence of disturbance. In addition, following the housing manipulation, IL-6 responses were more inhibited in short allele carriers (F1,16 = 8.59, P = 0.01). The findings confirm that the serotonin transporter gene-linked polymorphism is a distinctive marker of reactivity and inflammatory bias, perhaps in a more consistent manner in monkeys than found in many human studies.

Integrating partner professionals. The Early Explorers project: Peers Early Education Partnership and the health visiting service.

BACKGROUND: A range of voluntary sector organizations are involved in the delivery of services to children, particularly within the Early Year's sector and children's centres. Peers Early Education Partnership (PEEP) Early Explorers project is one example of the way in which explicit partnerships are being forged across statutory and voluntary sectors with the aim of improving outcomes for children and families. This paper reports an exploration of stakeholder views and experiences of two Early Explorer clinics located in areas of high deprivation. METHODS: Semi-structured interviews were conducted with a purposive sample of stakeholders (n= 25) from children's centres, PEEP, the health visiting service and service users. Data were fully transcribed and analysed using a thematic approach. RESULTS: The data suggest that the two key groups of stakeholders providing Early Explorer clinics (i.e. health visitors and PEEP practitioners) had quite different objectives in terms of their early goals for the clinic, but that despite these differences good progress was achieved in terms of working together effectively. All stakeholders including service users referred to the presence of PEEP as having improved the quality of the clinic environment, and participating mothers identified a wide range of benefits from the enhanced service. However, somewhat restricted views about the role of practitioners within the clinics were identified by users, and the findings suggest that although the early goals for the clinic had been exceeded, these may have been limited in terms of true 'partnership' working. CONCLUSIONS: Early Explorer clinics appeared to have enhanced the service provided within traditional child health clinics and to have provided practitioners with access to hard-to-reach families and parents with access to services that are consistent with the broader policy aims of improving parent-infant interaction. However, questions remain as to whether the benefit of 'partnership' working was fully realized.

Influence of the concentration of CO2 and SO2 on the absorption of CO2 by a lithium orthosilicate-based absorbent.

A novel, high temperature solid absorbent based on lithium orthosilicate (Li(4)SiO(4)) has shown promise for postcombustion CO(2) capture. Previous studies utilizing a clean, synthetic flue gas have shown that the absorbent has a high CO(2) capacity, >25 wt %, along with high absorption rates, lower heat of absorption and lower regeneration temperature than other solids such as calcium oxide. The current effort was aimed at evaluating the Li(4)SiO(4) based absorbent in the presence of contaminants found in typical flue gas, specifically SO(2), by cyclic exposure to gas mixtures containing CO(2), H(2)O (up to 25 vol. %), and SO(2) (up to 0.95 vol. %). In the absence of SO(2), a stable CO(2) capacity of ∼ 25 wt % over 25 cycles at 550 °C was achieved. The presence of SO(2), even at concentrations as low as 0.002 vol. %, resulted in an irreversible reaction with the absorbent and a decrease in CO(2) capacity. Analysis of SO(2)-exposed samples revealed that the absorbent reacted chemically and irreversibly with SO(2) at 550 °C forming Li(2)SO(4). Thus, industrial application would require desulfurization of flue gas prior to contacting the absorbent. Reactivity with SO(2) is not unique to the lithium orthosilicate material, so similar steps would be required for other absorbents that chemically react with SO(2).

Effects of aging and calorie restriction on white matter in rhesus macaques.

Rhesus macaques on a calorie restricted diet (CR) develop less age-related disease, have virtually no indication of diabetes, are protected against sarcopenia, and potentially live longer. Beneficial effects of caloric restriction likely include reductions in age-related inflammation and oxidative damage. Oligodendrocytes are particularly susceptible to inflammation and oxidative stress, therefore, we hypothesized that CR would have a beneficial effect on brain white matter and would attenuate age-related decline in this tissue. CR monkeys and controls underwent diffusion tensor imaging (DTI). A beneficial effect of CR indexed by DTI was observed in superior longitudinal fasciculus, fronto-occipital fasciculus, external capsule, and brainstem. Aging effects were observed in several regions, although CR appeared to attenuate age-related alterations in superior longitudinal fasciculus, frontal white matter, external capsule, right parahippocampal white matter, and dorsal occipital bundle. The results, however, were regionally specific and also suggested that CR is not salutary across all white matter. Further evaluation of this unique cohort of elderly primates to mortality will shed light on the ultimate benefits of an adult-onset, moderate CR diet for deferring brain aging.

Age-related changes in neural volume and microstructure associated with interleukin-6 are ameliorated by a calorie-restricted diet in old rhesus monkeys.

Systemic levels of proinflammatory cytokines such as interleukin-6 (IL-6) increase in old age and may contribute to neural atrophy in humans. We investigated IL-6 associations with age in T1-weighted segments and microstructural diffusion indices using MRI in aged rhesus monkeys (Macaca mulatta). Further, we determined if long-term 30% calorie restriction (CR) reduced IL-6 and attenuated its association with lower tissue volume and density. Voxel-based morphometry (VBM) and diffusion-weighted voxelwise analyses were conducted. IL-6 was associated with less global gray and white matter (GM and WM), as well as smaller parietal and temporal GM volumes. Lower fractional anisotropy (FA) was associated with higher IL-6 levels along the corpus callosum and various cortical and subcortical tracts. Higher IL-6 concentrations across subjects were also associated with increased mean diffusivity (MD) throughout many brain regions, particularly in corpus callosum, cingulum, and parietal, frontal, and prefrontal areas. CR monkeys had significantly lower IL-6 and less associated atrophy. An IL-6xCR interaction across modalities also indicated that CR mitigated IL-6 related changes in several brain regions compared to controls. Peripheral IL-6 levels were correlated with atrophy in regions sensitive to aging, and this relationship was decreased by CR.

Sure start: voices of the 'hard-to-reach'.

OBJECTIVES: This research aimed to look in depth at the factors affecting the ability of four Sure Start local programmes, based in a multicultural Midlands city, to engage with 'hard-to-reach' populations. METHODS: A variety of research strategies and methods were employed. Geographical information systems, participatory research methods and interviews were used in order to understand the extent of the challenge, and hear first hand, why parents may not get involved with Sure Start. The mapping exercise involved collation and mapping of postcode data with respect to boundaries and potential and actual users of Sure Start services. This made possible the identification of any geographical patterning in the distribution of service users and non-users. Participatory research methods were used with parents, enabling them to conduct short interviews within their own communities and make sense of the data collected. Interviews were also conducted with 70 parents across the city, recruited through local schools. RESULTS: The results indicate that parental decisions regarding Sure Start are the product of a complex interaction between numerous factors which may act as either barriers or facilitators to service utilization. CONCLUSIONS: The results suggest that a multi-method approach to data collection is useful and appropriate in gaining access to those parents who are non-users of the Sure Start services and enabling their voices to be heard. These findings offer some explanations and insight into the apparent ambivalent attitudes of some families toward Sure Start services. Implications for future practice are discussed.

Rates and social patterning of household smoking and breastfeeding in contrasting European settings.

OBJECTIVE: To compare rates and social patterning of household smoking and breastfeeding in families with newborn infants in birth cohorts in Coventry, UK and Veria, North Greece. METHODS: Infants born in 1996 in Coventry, 1999 in Veria were recruited into birth cohort studies using similar methodologies. In Coventry recruitment was by family health visitor at the primary visit; in Veria, hospital-based paediatricians enrolled infants at the neonatal examination. Data were collected at the initial contact on household smoking, type of feeding, and household socio-demographic characteristics. Rates of initial breastfeeding and household smoking with 95% confidence intervals were estimated and breastfeeding and household smoking regressed on parental education and housing tenure in logistic regression models. RESULTS: Data were available on 2612 Coventry infants and 773 Veria infants. Rates of household smoking and breastfeeding were higher in Veria compared to Coventry. In Coventry, living in rented accommodation and lower maternal and paternal education were associated with household smoking and bottle feeding. Logistic regression models fitted on initiation of breastfeeding failed to show social patterning in Veria but more educated mothers showed a longer duration of breastfeeding. Only low paternal education was associated with household smoking after adjustment for maternal education and housing tenure. CONCLUSIONS: Smoking and breastfeeding are more prevalent among households with young infants in Veria compared with Coventry. The social patterning of health-related behaviours noted in Coventry is less marked in Veria. The relevance of these findings for public health interventions in the contrasting settings is discussed.

Parent reported home smoking bans and toddler (18-30 month) smoke exposure: a cross-sectional survey.

AIMS: To study the relation between the use of parent reported home smoking bans and smoke exposure among children aged 18-30 months. METHODS: A total of 309 smoking households with children aged 18-30 months, who were part of the Coventry Cohort study, consented to participate in this cross-sectional survey. RESULTS: Although parents in almost 88% of smoking households reported using harm reduction strategies to protect their toddlers from smoke exposure, only 13.9% reported smoking bans in the house. Mean log urinary cotinine:creatinine ratio was significantly lower for those children whose parents reported no smoking in the house (1.11, 95% CI 0.64 to 1.49) compared with none/less strict strategies (1.87, 95% CI 1.64 to 2.10). In linear regression models fitted on log cotinine:creatinine ratio, no smoking in the house was independently associated with a significant reduction in cotinine:creatinine ratio (B = -0.55, 95% CI -0.89 to -0.20) after adjusting for mother's and partner's average daily cigarette consumption, housing tenure, and overcrowding. The final model accounted for 44.3% of the variance. CONCLUSIONS: Not smoking in the house was associated with a reduction in mean urinary cotinine:creatinine ratio in children aged 18-30 months; the relation persisted after adjustment for levels of mother's and partner's daily cigarette consumption and sociodemographic factors. Results suggest that home smoking bans in this age group have a small but significant effect on smoke exposure independent of levels of parental tobacco consumption.

Parental smoking and passive smoking in infants: fathers matter too.

This study examines mothers' and fathers' smoking patterns in different kinds of smoking households, and assesses their relative contribution to infants' exposure to environmental tobacco smoke. It uses data from a cross-sectional survey of 314 smoking households (infants: mean age 10 weeks) in Coventry and Birmingham, England, examining reported tobacco consumption and objective measures of exposure: the study infant's urinary cotinine:creatinine ratios and their mother's salivary cotinine. The study shows that both mothers' and fathers' tobacco smoke make substantial contributions to infant exposure to tobacco smoke. Households were more likely to contain a smoking father than mother, with over two-thirds of households including a smoking father. In households where both parents smoke, fathers' tobacco consumption was found to be significantly higher than in households where only the father smokes. This suggests that the interaction between parents needs to be considered rather than focusing on mothers' or fathers' smoking behaviour in isolation. The implications for health promotion programmes are discussed, particularly the need to place more emphasis on tackling fathers' smoking. Currently, fathers' smoking receives far less research or health promotion attention than mothers' smoking. Protecting infants from fathers' as well as mothers' smoking is key to reducing environmental tobacco exposure in early infancy, when the risk of Sudden Infant Death is highest.

Services for pre-school children with behaviour problems in a Midlands city.

OBJECTIVES: To study the services for pre-school children with behaviour problems in a Midlands city and the level of co-ordination and co-operation between providers. SETTING: A socially and ethnically diverse Midlands city in the UK. METHODS: Survey methods were employed with city health visitors in order to determine their role and identify service providers. Service providers from different agencies were interviewed and data collected related to service offered, materials used, theoretical basis of interventions, referrals to and from the service, inclusion and exclusion criteria and co-ordination and co-operation with other providers. Themes were identified related to the content and process of the services using qualitative data analysis methods. Frequencies of themes were estimated for different provider groups. RESULTS: Health visitors and nursery nurses working in the primary care services were the primary point of contact for children with pre-school behaviour problems. Nursery nurses were one of the major sources of referral for children with pre-school behaviour problems and a significant majority of these providers had not received any specific training for this role. The majority of the providers used evidence-based programmes but few adhered strictly to a particular programme and instead used a mixture of materials drawn from different programmes. Many health service providers in particular offered interventions to parents on a one-to-one basis only. Most providers used behaviour modification approaches. While many providers claimed to have knowledge of other local providers and have good links, there was little evidence of co-ordination within and between agencies. CONCLUSIONS: While there appears to be high levels of activity by providers from both statutory and voluntary sectors in providing services for pre-school children with behaviour problems, there is evidence to suggest that some of the main providers of services are not being adequately prepared and supported in the role. There is a lack of co-ordination within and between services, and indication that evidence-based programmes are being modified and used in an ad hoc manner. It is concluded that surveys of this nature may be an important preliminary step in establishing co-ordinated services for the primary and secondary prevention of pre-school behaviour problems.

Social patterning and prediction of parent-reported behaviour problems at 3 years in a cohort study.

OBJECTIVE: To study the determinants of parent-reported behaviour problems at 3 years and the value of behaviour problems reported at 8 and 18 months as predictors of behaviour at 3 years STUDY DESIGN: A whole year birth cohort SETTING: Coventry MAIN OUTCOMES: Parent-reported behaviour problems at 3 years PARTICIPANTS: A total of 2580 infants were enrolled into the Coventry Cohort Study at the birth visit by their family health visitor. Data on parent-reported behaviour at all three ages (8 months, 18 months and 3 years) were available on 775 infants. RESULTS: Living in rented accommodation [adjusted OR 2.38 (95% CI 1.36, 4.21); OR, odds ratio; CI, confidence intervals] and living in a smoking household [adjusted OR 2.47 (95% CI 1.53, 3.99)] were independently associated with parent-reported behaviour problems at 3 years after controlling for other sociodemographic variables in logistic regression. The risk of behaviour problems at 3 years was increased in those reporting behaviour problems at 8 months [OR 3.77 (95% CI 1.73, 8.20)] and 18 months [OR 5.84 (95% CI 3.34, 10.23)] after adjustment for sociodemographic variables and other health problems. Behaviour at 8 months as a predictor of behaviour at 3 years had a sensitivity of 13.9%, a specificity of 95.7%, a positive predictive value of 32.6%, and positive and negative likelihood ratios of 3.23 and 0.90. For behaviour at 18 months, the sensitivity was 35.6%, the specificity 92.9%, the positive predictive value 42.9%, and positive and negative likelihood ratios 5.01 and 0.69. CONCLUSIONS: Parent-reported behaviour problems at 8 and 18 months are highly specific but not particularly sensitive as predictors of behaviour problems at 3 years. Assuming the availability of an effective early intervention, use of a question such as that in the Warwick Child Health and Morbidity Profile at 8 and 18 months will identify, respectively, 21% and 36% of children at risk of parent-reported behaviour problems at 3 years.

Parent reported longstanding health problems in early childhood: a cohort study.

AIM: To study changing prevalence and correlates of longstanding health problems across early childhood. METHODS: Of 2576 infants enrolled in the Coventry Cohort Study at birth, parents of 2157 at 8 weeks, 1752 at 8 months, 1521 at 18 months, and 1182 at 3 years completed the Warwick Child Health and Morbidity Profile. RESULTS: The prevalence of parent reported longstanding health problems was 4.3% at 8 months, 6.9% at 18 months, and 9.7% at 3 years. Congenital anomalies accounted for 42.1% of longstanding health problems at 8 months, 40.0% at 18 months, and 27.8% at 3 years. The proportion accounted for by asthma was 17.1% at 8 months, 21.9% at 18 months, and 24.3% at 3 years. In each age period, children reported to have longstanding health problems were at increased risk of impaired functional health, poorer general health, and reduced health related quality of life. Low birthweight infants were most at risk of longstanding health problems at 8 months. By 3 years, risk of longstanding health problems was associated with living in rented accommodation and living in a smoking household. CONCLUSIONS: The prevalence of parent reported longstanding health problems increased across early childhood. Congenital anomalies constituted the major cause, particularly in infancy, with asthma and developmental delay becoming more prominent by 3 years of age. Social patterning of longstanding health problems and the association with smoking were clearly established by 3 years of age but the relation may have been mediated by low birth weight earlier in infancy.

Disruptions of social relationships accentuate the association between emotional distress and menstrual pain in young women.

This study examined the effects of social support on dysmenorrhea and whether social support moderates the relationship between negative emotions and painful symptoms. Women (N = 184) completed questionnaires on menstrual symptoms, depression, anxiety, and social networks. Depression and anxiety were strongly associated with menstrual pain. Women who no longer had access to their prior support providers manifested more symptoms than did women with stable social relations. In addition, this disruption in their social networks moderated the relationship between distress and menstrual pain. Results indicate that loss of social support is a significant contributor to menstrual symptoms and point to the importance of considering specific aspects of social support in studying its effect on health.

Intrinsic and environmental influences on immune senescence in the aged monkey.

Several factors associated with the age-related decline in immunity were examined in three studies on aged rhesus monkeys. Natural killer (NK) cell activity was found to be low in many monkeys after 20 years of age, but exceptionally long-lived animals, older than 25 years, often had vigorous cytolytic responses. When NK activity was decreased in an aged monkey, it was predictive of fewer years of survival and a younger age at death. This prediction of mortality was associated with one nonimmune biomarker of aging in the monkey: nail growth rate. Monkeys with very slow nail growth and low NK activity were likely to die sooner. Although these findings might suggest an immutable course for the aging process, the housing conditions of old monkeys also had a pronounced effect on their NK activity. The highest NK responses were found in old monkeys housed with just one other old animal when compared to living alone or with just a young, juvenile monkey. It remains to be determined whether this type of psychosocial influence could have a sustained effect on immunity and ultimately change the pace of aging and time to mortality.