Clustering and Micro-immiscibility in Alcohol-Water Mixtures: Evidence from Molecular Dynamics Simulations

We have investigated the hydrogen-bonded structures in liquid methanol and a 7:3 mole fraction aqueous solution using classical Molecular Dynamics simulations at 298K and ambient pressure. We find that, in contrast to recent predictions from X-ray emission studies, the hydrogen-bonded structure in liquid methanol is dominated by chain and small ring structures. In the methanol-rich solution, we find evidence of micro-immiscibility, supporting recent conclusions derived from neutron diffraction data.Comment: 5 pages, 4 figure

Starburst and AGN activity in ultraluminous infrared galaxies

(Abridged) We examine the power source of 41 local Ultraluminous Infrared Galaxies using archival infrared and optical photometry. We fit the observed Spectral Energy Distributions (SEDs) with starburst and AGN components; each component being drawn from a family of templates. We find all of the sample require a starburst, whereas only half require an AGN. In 90% of the sample the starburst provides over half the IR emission, with a mean fractional luminosity of 82%. When combined with other galaxy samples we find that starburst and AGN luminosities correlate over 6 decades in IR luminosity suggesting that a common factor governs both luminosities, plausibly the gas masses in the nuclear regions. We find that the mid-IR 7.7 micron line-continuum ratio is no indication of the starburst luminosity, or the fractional AGN luminosity, and therefore that this ratio is not a reliable diagnostic of the power source in ULIRGs. We propose that the scatter in the radio-IR correlation in ULIRGs is due to a skewed starburst IMF and/or relic relativistic electrons from a previous starburst, rather than contamination from an obscured AGN. We show that most ULIRGs undergo multiple starbursts during their lifetime, and by inference that mergers between more than two galaxies may be common amongst ULIRGs. Our results support the evolutionary model for ULIRGs proposed by Farrah et al 2001, where they can follow many different evolutionary paths of starburst and AGN activity in transforming merging spiral galaxies into elliptical galaxies, but that most do not go through an optical QSO phase. The lower level of AGN activity in our local sample than in z~1 HLIRGs implies that the two samples are distinct populations. We postulate that different galaxy formation processes at high-z are responsible for this difference.Comment: 24 pages, 8 figures. Accepted for publication in MNRA

General hospital care for people with intellectual disabilities

Purpose – The purpose of this paper is to explore the extent of compliance of commissioners and providers of hospital services in England with their duty under equalities legislation to be aware of patients with intellectual disabilities as a first step to making appropriate provision for their consequent specific needs. Design/methodology/approach – National survey of healthcare commissioners undertaken as part of an annual learning disabilities services audit. Findings – In total, 41.4 per cent of local areas were unable to supply information about numbers of people with intellectual disabilities among those admitted to hospital, 46.7 and 48 per cent, respectively, could not supply this information about out-patient and accident and emergency department attenders. Figures supplied by those able to provide data varied very substantially and overall were so low as to suggest considerable numbers had been missed. Research limitations/implications – The study is testing what local health commissioners are able to find out from hospitals. The authors do not know the accuracy of the data they reported. Practical implications – The study suggests approaching half of healthcare commissioners in England have little or no information about the extent of proper adjustment of hospital care for people with intellectual disability in their area. Their responsibility to assure this has been repeatedly asserted by government. Social implications – The study indicates a need for more work to improve hospital care for people with intellectual disabilities. Originality/value – This was a government sponsored national study to which local healthcare commissioners were expected to contribute

What is the meaning and nature of active play for today's children in the UK?

<p>Abstract</p> <p>Background</p> <p>Preventing the decline in physical activity which occurs around 10-11 years of age is a public health priority. Physically active play can make unique contributions to children's development which cannot be obtained from more structured forms of physical activity. Encouraging active play in children's leisure time has potential to increase physical activity levels while promoting optimal child development. Aspired wisdom states that contemporary British children no longer play outdoors, but systematic evidence for this is lacking. We need to build a more informed picture of contemporary children's play before we consider interventions to increase it.</p> <p>Methods</p> <p>Eleven focus groups were conducted with 77, 10-11 year old children from four primary schools in Bristol, UK. Focus groups examined: 1) children's perceptions of 'play'; 2) how much of their play is active play; and 3) contexts of children's active play. All focus groups were audio-taped and transcribed verbatim. Data were analysed using a thematic approach.</p> <p>Results</p> <p>Children's perceptions of play were broad and included both physically active and sedentary behaviours. Children reported that they frequently engaged in active play and valued both the physical and social benefits it provided. Whereas boys frequently reported having a 'kick about' or riding bikes as their preferred forms of active play, girls were less likely to report a specific activity. Additionally, boys reported greater independent mobility in their active play compared to girls. Finally, boys were more likely to report playing with neighbourhood friends but girls more frequently reported playing with family members.</p> <p>Conclusions</p> <p>Promoting active play in children's leisure time may increase the physical activity of children, but interventions may need to be tailored according to gender.</p

Sub-millimeter emission from type Ia supernova host galaxies at z=0.5

We present deep sub-millimetre observations of seventeen galaxies at z=0.5, selected through being hosts of a type 1a supernova. Two galaxies are detected directly, and the sample is detected statistically with a mean 850 micron flux of 1.01mJy +/- 0.33mJy, which is 25% - 135% higher than locally. We infer that the mean value of A_v in normal galaxies at z=0.5 is comparable to or greater than the mean A_v in local normal galaxies, in agreement with galaxy chemical evolution models and indirect observational evidence. Scaling from the local value given by Rowan-Robinson (2003) gives a mean extinction at z=0.5 of A_v = 0.56 +/- 0.17. The dust in the brightest sub-mm object in our sample is best interpreted as normal `cirrus' dust similar to that seen locally. The detection rate of our sample suggests that some sources found in blank-field sub-mm surveys may not be high redshift starbursts, but rather cirrus galaxies at moderate redshifts and with lower star formation rates. Finally, an increase in host dust extinction with redshift may impact the cosmological results from distant supernova searches. This emphasizes the need to carefully monitor dust extinction when using type Ia supernovae to measure the cosmological parameters.Comment: 6 pages, 2 figures. ApJ accepte

Development of scales to assess children's perceptions of friend and parental influences on physical activity

<p>Abstract</p> <p>Background</p> <p>Many children do not meet physical activity guidelines. Parents and friends are likely to influence children's physical activity but there is a shortage of measures that are able to capture these influences.</p> <p>Methods</p> <p>A new questionnaire with the following three scales was developed: 1) <it>Parental influence on physical activity</it>; 2) <it>Motives for activity with friends </it>scale; and 3) <it>Physical activity and sedentary group normative values</it>. Content for each scale was informed by qualitative work. One hundred and seventy three, 10-11 year old children completed the new questionnaire twice, one week apart. Participants also wore an accelerometer for 5 days and mean minutes of moderate to vigorous physical activity, light physical activity and sedentary time per day were obtained. Test-retest reliability of the items was calculated and Principal Component analysis of the scales performed and sub-scales produced. Alphas were calculated for main scales and sub-scales. Correlations were calculated among sub-scales. Correlations between each sub-scale and accelerometer physical activity variables were calculated for all participants and stratified by sex.</p> <p>Results</p> <p>The Parental influence scale yielded four factors which accounted for 67.5% of the variance in the items and had good (α > 0.7) internal consistency. The Motives for physical activity scale yielded four factors that accounted for 66.1% and had good internal consistency. The Physical activity norms scale yielded 4 factors that accounted for 67.4% of the variance, with good internal consistency for the sub-scales and alpha of .642 for the overall scale. Associations between the sub-scales and physical activity differed by sex. Although only 6 of the 11 sub-scales were significantly correlated with physical activity there were a number of associations that were positively correlated >0.15 indicating that these factors may contribute to the explanation of children's physical activity.</p> <p>Conclusion</p> <p>Three scales that assess how parents, friends and group normative values may be associated with children's physical activity have been shown to be reliable and internally consistent. Examination of the extent to which these new scales improve our understanding of children's physical activity in datasets with a range of participant and family characteristics is needed.</p