The application of passive sampler (DGT) technology for improved understanding of metal behaviour at a marine disposal site

Metal behaviour and availability at a contaminated dredge material disposal site within UK waters has been investigated using Diffusive Gradient in Thin films (DGT) passive sampling technology. Three stations representing contrasting history and presence of maintenance dredge disposal, including a control station outside the disposal site, have been studied and depth profiles of fluxes of different metals (Fe, Mn, Pb, Cu, Cd, Cr, Ni, Zn) to the binding gel (Chelex 100) have been derived. Higher flux rates and shallower mobilisation of metals (Mn and Fe) to the binding gel were observed at the disposal stations compared to the control station. Here we describe metal mobilization at different depths, linking the remobilization of Fe2+ and Mn2+ to the sediment (re)supply of other heavy metals of interest with a focus on Cd, Ni and Pb and as they are on the Water Framework Directive (WFD) list of priority substances and OSPAR list of priority pollutants. Results showed that Cd, Pb and Ni exhibited signs of resupply at the sediment-water interface (SWI). There was a potential increased mobilisation and source to the water column of Pb and Ni at the disposal site stations, but there was no Cd source, despite higher total loadings. This information has the potential to improve our current understanding of metal cycles at disposal sites. This work can be used as an indication of likely metal bioavailability and also assist in determining whether the sites act as sources or sinks of heavy metals. This information could assist disposal site monitoring and dredge material licensing

Efficacy of infant simulator programmes to prevent teenage pregnancy: a school-based cluster randomised trial in Western Australia

Background: Infant simulator-based programmes seek to prevent teenage pregnancy. They are utilised in western and developing countries but, despite growing popularity, there is no published evidence of their long-term impact. The aim of this trial was to investigate the effect of such a programme, the Virtual Infant Parenting (VIP) Programme, on the pregnancy outcomes of birth and induced abortion. Methods: Fifty-seven of 66 eligible schools (86%) in Perth, Western Australia enrolled in the pragmatic clustered (by school) randomised trial (ISRCTN24952438) with even randomisation to the intervention and control groups. Between 2003 and 2006, the VIP programme was administered to 1,267 girls in the intervention schools, while 1,567 girls in the control schools received the standard health education curriculum. Participants were aged 13-15 years and were followed until age 20 via data linkage to hospital medical and abortion clinic records. Log binomial and Cox proportional hazards regression was used to test for differences in pregnancy rates between study groups. Findings: Compared to girls Findings: Compared to girls in the control group, a higher proportion of girls in the intervention group recorded at least one birth (7.6%, n=97; 4·3%, n=67) or at least one abortion as the first pregnancy event (8.9%, n=113; 6.4%, n=101). After adjustment for potential confounding, the intervention group had a higher overall pregnancy risk (RR = 1·36, 95% CI 1.10–1·67, p=0.003) compared to the control group. Similar results were obtained using proportional hazard models (HR = 1.35, 95% CI 1.10–1·67, p=0·016). Interpretation: The infant-simulator based VIP Programme did not achieve its aim of reducing teenage pregnancy. Girls in the intervention group were more likely to experience a birth or an induced abortion than those in the control group before turning 20 years of age. Funding: The Health Promotion Research Foundation of Western Australia (Healthway), Lotteries WA, the Western Australian Department of Education and Training and the Western Australian Department of Health

Early risk factors for adolescent antisocial behaviour: an Australian longitudinal study

Objective: This investigation utilizes data from an Australian longitudinal study to identify early risk factors for adolescent antisocial behaviour. Method: Analyses are based on data from the Mater University Study of Pregnancy, an on-going longitudinal investigation of women’s and children’s health and development involving over 8000 participants. Five types of risk factors (child characteristics, perinatal factors, maternal/familial characteristics, maternal pre- and post-natal substance use and parenting practices) were included in analyses and were based on maternal reports, child assessments and medical records. Adolescent antisocial behaviour was measured when children were 14 years old, using the delinquency subscale of the Child Behaviour Checklist. Results: Based on a series of logistic regression models, significant risk factors for adolescent antisocial behaviour included children’s prior problem behaviour (i.e. aggression and attention/restlessness problems at age 5 years) and marital instability, which doubled or tripled the odds of antisocial behaviour. Perinatal factors, maternal substance use, and parenting practices were relatively poor predictors of antisocial behaviour. Conclusions: Few studies have assessed early predictors of antisocial behaviour in Australia and the current results can be used to inform prevention programs that target risk factors likely to lead to problem outcomes for Australian youth

Disease-specific, neurosphere-derived cells as models for brain disorders

There is a pressing need for patient-derived cell models of brain diseases that are relevant and robust enough to produce the large quantities of cells required for molecular and functional analyses. We describe here a new cell model based on patient-derived cells from the human olfactory mucosa, the organ of smell, which regenerates throughout life from neural stem cells. Olfactory mucosa biopsies were obtained from healthy controls and patients with either schizophrenia, a neurodevelopmental psychiatric disorder, or Parkinson's disease, a neurodegenerative disease. Biopsies were dissociated and grown as neurospheres in defined medium. Neurosphere-derived cell lines were grown in serum-containing medium as adherent monolayers and stored frozen. By comparing 42 patient and control cell lines we demonstrated significant disease-specific alterations in gene expression, protein expression and cell function, including dysregulated neurodevelopmental pathways in schizophrenia and dysregulated mitochondrial function, oxidative stress and xenobiotic metabolism in Parkinson's disease. The study has identified new candidate genes and cell pathways for future investigation. Fibroblasts from schizophrenia patients did not show these differences. Olfactory neurosphere-derived cells have many advantages over embryonic stem cells and induced pluripotent stem cells as models for brain diseases. They do not require genetic reprogramming and they can be obtained from adults with complex genetic diseases. They will be useful for understanding disease aetiology, for diagnostics and for drug discovery

Post-peak fracture behavior during direct shear tests of rock joints

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Bottom mixed layer oxygen dynamics in the Celtic Sea

The seasonally stratified continental shelf seas are highly productive, economically important environments which are under considerable pressure from human activity. Global dissolved oxygen concentrations have shown rapid reductions in response to anthropogenic forcing since at least the middle of the twentieth century. Oxygen consumption is at the same time linked to the cycling of atmospheric carbon, with oxygen being a proxy for carbon remineralisation and the release of CO2. In the seasonally stratified seas the bottom mixed layer (BML) is partially isolated from the atmosphere and is thus controlled by interplay between oxygen consumption processes, vertical and horizontal advection. Oxygen consumption rates can be both spatially and temporally dynamic, but these dynamics are often missed with incubation based techniques. Here we adopt a Bayesian approach to determining total BML oxygen consumption rates from a high resolution oxygen time-series. This incorporates both our knowledge and our uncertainty of the various processes which control the oxygen inventory. Total BML rates integrate both processes in the water column and at the sediment interface. These observations span the stratified period of the Celtic Sea and across both sandy and muddy sediment types. We show how horizontal advection, tidal forcing and vertical mixing together control the bottom mixed layer oxygen concentrations at various times over the stratified period. Our muddy-sand site shows cyclic spring-neap mediated changes in oxygen consumption driven by the frequent resuspension or ventilation of the seabed. We see evidence for prolonged periods of increased vertical mixing which provide the ventilation necessary to support the high rates of consumption observed

Correlates of self-reported coercive parenting of preschool-aged children at high risk for the development of conduct problems.

Objective: This study examines the correlates of coercive parenting in a high-risk sample of 305 three-year-old children likely to develop later conduct problems. As parental coercion has been identified as a significant risk factor for future psychopathology, the study sought to identify modifiable inter and intra-personal factors most closely associated with coercion. Method: Key variables known to place young children at future risk, such as maternal mood states, current child behaviour problems, demographic characteristics such as low income, past mental health problems and parents’ sense of competence, were analyzed based on parent-report measures and clinical interviews. Correlational and heirachical regression analysis identified key predictors of coercion. Results: Three variables emerged as the strongest predictors of maternal coercion: selfefficacy, child behaviour and maternal depression. Demographic factors contributed little to the model. Conclusions: Enhancing parental self-efficacy, especially specific parenting tasks with disruptive young children has the potential to make a significant contribution toward prevention of future conduct problems

Benthic pH gradients across a range of shelf sea sediment types linked to sediment characteristics and seasonal variability

This study used microelectrodes to record pH profiles in fresh shelf sea sediment cores collected across a range of different sediment types within the Celtic Sea. Spatial and temporal variability was captured during repeated measurements in 2014 and 2015. Concurrently recorded oxygen microelectrode profiles and other sedimentary parameters provide a detailed context for interpretation of the pH data. Clear differences in profiles were observed between sediment type, location and season. Notably, very steep pH gradients exist within the surface sediments (10–20 mm), where decreases greater than 0.5 pH units were observed. Steep gradients were particularly apparent in fine cohesive sediments, less so in permeable sandier matrices. We hypothesise that the gradients are likely caused by aerobic organic matter respiration close to the sediment–water interface or oxidation of reduced species at the base of the oxic zone (NH4+, Mn2+, Fe2+, S−). Statistical analysis suggests the variability in the depth of the pH minima is controlled spatially by the oxygen penetration depth, and seasonally by the input and remineralisation of deposited organic phytodetritus. Below the pH minima the observed pH remained consistently low to maximum electrode penetration (ca. 60 mm), indicating an absence of sub-oxic processes generating H+ or balanced removal processes within this layer. Thus, a climatology of sediment surface porewater pH is provided against which to examine biogeochemical processes. This enhances our understanding of benthic pH processes, particularly in the context of human impacts, seabed integrity, and future climate changes, providing vital information for modelling benthic response under future climate scenarios

Gender, Culture and Intervention: Exploring Differences between Aboriginal and Non-Aboriginal Children’s Responses to an Early Intervention Programme

Evaluation of a group parenting programme in the Northern Territory of Australia showed significant differences in benefits for Aboriginal and non-Aboriginal boys and girls. The analysis considers whether boys and girls from different cultural backgrounds present with different problems; whether parental expectations for boys and girls differ and whether the intervention activates different responses in different settings. Conclusions suggest that there is a need to closely examine the ‘cultural logic’ of interventions, the appropriateness of their assumptions about child development and hypothesised mechanisms of change in different settings

Suicides in Aboriginal and non-Aboriginal people following hospital admission for suicidal ideation and self-harm: A retrospective cohort data linkage study from the Northern Territory

Purpose: This study aimed to explore risk factors for suicide in Aboriginal and non-Aboriginal people following hospital admission for suicidal ideation and self-harm in the Northern Territory, Australia to help clarify opportunities for improved care and intervention for these population groups. Methods: Individuals with at least one hospital admission involving suicidal ideation and/or self-harm between 1 July 2001 and 31 December 2013 were retrospectively recruited and followed up using linked mortality records to 31 December 2014. Survival analyses stratified by Indigenous status identified socio-demographic and clinical characteristics from index hospital admissions associated with suicide. Results: Just over half of the 4391 cohort members identified as Aboriginal (n = 2304; 52.4%). By 2014, 281 deaths were observed comprising 68 suicides, representing a 2.6% and 2.0% probability of suicide for Aboriginal and non-Aboriginal people, respectively. After adjusting for other characteristics, a higher risk of suicide was associated with male sex (Aboriginal adjusted hazard ratio: 4.14; 95% confidence interval: [1.76, 9.75]; non-Aboriginal adjusted hazard ratio: 5.96; 95% confidence interval: [1.98, 17.88]) and repeat hospital admissions involving self-harm (Aboriginal adjusted hazard ratio: 1.37; 95% confidence interval: [1.21, 1.55]; non-Aboriginal adjusted hazard ratio: 1.29; 95% confidence interval: [1.10, 1.51]). Severe mental disorders were associated with a four times higher risk of suicide (adjusted hazard ratio: 4.23; 95% confidence interval: [1.93, 9.27]) in Aboriginal people only. Conclusion: The findings highlight non-clinical risk factors for suicide that suggest the need for comprehensive psychosocial assessment tailored to Aboriginal and non-Aboriginal people hospitalised with suicidal ideation or self-harm. Implementing appropriate management and aftercare within a broader public health framework is needed to support recovery and reduce long-term suicide risk in the community, especially for Aboriginal people and males