Water Availability and Deformation Processes in Smectite-Rich Gouges During Seismic Slip

Smectite clays occur in subduction zone fault cores at shallow depth (approximately 1 km; e.g., Japan Trench) and landslide d\ue9collements (e.g., Vajont, Italy, 1963). The availability of pore fluids affects the likelihood that seismic slip propagates from deeper to shallow fault depths or that a landslide accelerates to its final collapse. To investigate the deformation processes active during seismic faulting we performed friction experiments with a rotary machine on 2-mm-thick smectite-rich gouge layers (70/30 wt % Ca-montmorillonite/opal) sheared at 5-MPa normal stress, at slip rates of 0.001, 0.01, 0.1, and 1.3 m/s, and total displacement of 3 m. Experiments were performed on predried gouges under vacuum, under room humidity and under partly saturated conditions. The fault shear strength measured in the experiments was included in a one-dimensional numerical model incorporating frictional heating, thermal, and thermochemical pressurization. Quantitative X-ray powder diffraction and scanning electron microscopy investigations were performed on pristine and deformed smectite-rich gouges. Under dry conditions, cataclasis and amorphization dominated at slip rates of 0.001\u20130.1 m/s, whereas grain size sensitive flow and, under vacuum, frictional melting occurred at fast slip rates (1.3 m/s). Under partly saturated conditions, frictional slip in a smectite foliation occurred in combination with pressurization of water by shear-enhanced compaction and, for V = 0.01\u20131.3 m/s, with thermal pressurization. Pseudotachylytes, the only reliable microstructural markers for seismic slip, formed only with large frictional power (>2 MW/m2), which could be achieved at shallow depth with high slip rates, or, at depth, with high shear stress in dehydrated smectites

Measuring commissioners’ willingness-to-pay for community based childhood obesity prevention programmes using a discrete choice experiment

Background: In the UK, rates of childhood obesity remain high. Community based programmes for child obesity prevention are available to be commissioned by local authorities. However, there is a lack of evidence regarding how programmes are commissioned and which attributes of programmes are valued most by commissioners. The aim of this study was to determine the factors that decision-makers prioritise when commissioning programmes that target childhood obesity prevention. Methods: An online discrete choice experiment (DCE) was used to survey commissioners and decision makers in the UK to assess their willingness-to-pay for childhood obesity programmes. Results: A total of 64 commissioners and other decision makers completed the DCE. The impact of programmes on behavioural outcomes was prioritised, with participants willing to pay an extra £16,600/year if average daily fruit and vegetable intake increased for each child by one additional portion. Participants also prioritised programmes that had greater number of parents fully completing them, and were willing to pay an extra £4810/year for every additional parent completing a programme. The number of parents enrolling in a programme (holding the number completing fixed) and hours of staff time required did not significantly influence choices. Conclusions: Emphasis on high programme completion rates and success increasing children’s fruit and vegetable intake has potential to increase commissioning of community based obesity prevention programmes

Cultural basis of social ‘deficits’ in autism spectrum disorders

There is very little research that specifically looks at how autism spectrum disorders are perceived in various communities. This qualitative research was conducted with parents who had children on the autistic spectrum belonging to four different ethnic communities (White British, Somali, West African and South Asian- 63 in total) and living in the UK. The study found that the importance that the parents give to various social skills varied on the basis of their cultural background and the gender of the parent. This is an important aspect to consider while providing support and services to individuals on the autism spectrum and their family members if the services have to be appropriate for their needs. This consideration would also enable the individuals on the autism spectrum to develop appropriate social skills required within their cultural groups. This is a preliminary study and further research on the topic is required

Pathways to economic well-being among teenage mothers in Great Britain

The present study examines pathways to independence from social welfare among 738 teenage mothers, participants of the 1970 British Cohort Study, who were followed up at age 30 years. Using a longitudinal design, a pathway model is tested, examining linkages between family social background, cognitive ability, school motivation, and individual investments in education, as well as work- and family-related roles. The most important factors associated with financial independence by age 30 are continued attachment to the labor market as well as a stable relationship with a partner (not necessarily the father of the child). Pathways to financial independence, in turn, are predicted through own cognitive resources, school motivation, and family cohesion. Implications of findings for policy making are discussed.© 2010 Hogrefe Publishing

Substrate-induced band gap opening in epitaxial graphene

Graphene has shown great application potentials as the host material for next generation electronic devices. However, despite its intriguing properties, one of the biggest hurdles for graphene to be useful as an electronic material is its lacking of an energy gap in the electronic spectra. This, for example, prevents the use of graphene in making transistors. Although several proposals have been made to open a gap in graphene's electronic spectra, they all require complex engineering of the graphene layer. Here we show that when graphene is epitaxially grown on the SiC substrate, a gap of ~ 0.26 is produced. This gap decreases as the sample thickness increases and eventually approaches zero when the number of layers exceeds four. We propose that the origin of this gap is the breaking of sublattice symmetry owing to the graphene-substrate interaction. We believe our results highlight a promising direction for band gap engineering of graphene.Comment: 10 pages, 4 figures; updated reference

Microscopic Polarization in Bilayer Graphene

Bilayer graphene has drawn significant attention due to the opening of a band gap in its low energy electronic spectrum, which offers a promising route to electronic applications. The gap can be either tunable through an external electric field or spontaneously formed through an interaction-induced symmetry breaking. Our scanning tunneling measurements reveal the microscopic nature of the bilayer gap to be very different from what is observed in previous macroscopic measurements or expected from current theoretical models. The potential difference between the layers, which is proportional to charge imbalance and determines the gap value, shows strong dependence on the disorder potential, varying spatially in both magnitude and sign on a microscopic level. Furthermore, the gap does not vanish at small charge densities. Additional interaction-induced effects are observed in a magnetic field with the opening of a subgap when the zero orbital Landau level is placed at the Fermi energy

Early visual foraging in relationship to familial risk for autism and hyperactivity/inattention

Objective. Information foraging is atypical in both autism spectrum disorders (ASDs) and ADHD; however, while ASD is associated with restricted exploration and preference for sameness, ADHD is characterized by hyperactivity and increased novelty seeking. Here, we ask whether similar biases are present in visual foraging in younger siblings of children with a diagnosis of ASD with or without additional high levels of hyperactivity and inattention. Method. Fifty-four low-risk controls (LR) and 50 high-risk siblings (HR) took part in an eye-tracking study at 8 and 14 months and at 3 years of age. Results. At 8 months, siblings of children with ASD and low levels of hyperactivity/inattention (HR/ASD-HI) were more likely to return to previously visited areas in the visual scene than were LR and siblings of children with ASD and high levels of hyperactivity/inattention (HR/ASD+HI). Conclusion. We show that visual foraging is atypical in infants at-risk for ASD. We also reveal a paradoxical effect, in that additional family risk for ADHD core symptoms mitigates the effect of ASD risk on visual information foraging

WHO European Childhood Obesity Surveillance Initiative: body mass index and level of overweight among 6-9-year-old children from school year 2007/2008 to school year 2009/2010

Background: The World Health Organization (WHO) Regional Office for Europe has established the Childhood Obesity Surveillance Initiative (COSI) to monitor changes in overweight in primary-school children. The aims of this paper are to present the anthropometric results of COSI Round 2 (2009/2010) and to explore changes in body mass index (BMI) and overweight among children within and across nine countries from school years 2007/2008 to 2009/2010. Methods: Using cross-sectional nationally representative samples of 6−9-year-olds, BMI, anthropometric Z-scores and overweight prevalence were derived from measured weight and height. Significant changes between rounds were assessed using variance and t-tests analyses. Results: At Round 2, the prevalence of overweight (including obesity; WHO definitions) ranged from 18% to 57% among boys and from 18% to 50% among girls; 6 − 31% of boys and 5 − 21% of girls were obese. Southern European countries had the highest overweight prevalence. Between rounds, the absolute change in mean BMI (range: from −0.4 to +0.3) and BMI-for-age Z-scores (range: from −0.21 to +0.14) varied statistically significantly across countries. The highest significant decrease in BMI-for-age Z-scores was found in countries with higher absolute BMI values and the highest significant increase in countries with lower BMI values. The highest significant decrease in overweight prevalence was observed in Italy, Portugal and Slovenia and the highest significant increase in Latvia and Norway. Conclusions: Changes in BMI and prevalence of overweight over a two-year period varied significantly among European countries. It may be that countries with higher prevalence of overweight in COSI Round 1 have implemented interventions to try to remedy this situation