6,275 research outputs found

    Differences between European birthweight standards: impact on classification of ‘small for gestational age’

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    We describe a quantitative and comparative review of a selection of European birthweight standards for gestational age for singletons, to enable appropriate choices to be made for clinical and research use. Differences between median values at term across standards in 10 regions and misclassification of ‘small for gestational age’ (SGA), were studied. Sex and parity differences, exclusion criteria, and methods of construction were considered. There was wide variation between countries in exclusion criteria, methods of calculating standards, and median birthweight at term. The lightest standards (e.g. France's medians are 255g lower than Norway's medians) were associated with fewer exclusion criteria. Up to 20% of the population used in the construction of the Scottish standard would be classified as SGA using the Norwegian standard. Substantial misclassification of SGA is possible. Assumptions about variation used in the construction of some standards were not justified. It is not possible to conclude that there are real differences in birthweight standards between European countries. Country-based standards control for some population features but add misclassification due to the differing ways in which standards are derived. Standards should be chosen to reflect clinical or research need. If standards stratified by sex or parity are not available, adjustments should be made. In multinational studies, comparisons should be made between results using both a common standard and country-based standards

    Structure and spacing of cellulose microfibrils in woody cell walls of dicots

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    The structure of cellulose microfibrils in situ in wood from the dicotyledonous (hardwood) species cherry and birch, and the vascular tissue from sunflower stems, was examined by wide-angle X-ray and neutron scattering (WAXS and WANS) and small-angle neutron scattering (SANS). Deuteration of accessible cellulose chains followed by WANS showed that these chains were packed at similar spacings to crystalline cellulose, consistent with their inclusion in the microfibril dimensions and with a location at the surface of the microfibrils. Using the Scherrer equation and correcting for considerable lateral disorder, the microfibril dimensions of cherry, birch and sunflower microfibrils perpendicular to the [200] crystal plane were estimated as 3.0, 3.4 and 3.3 nm respectively. The lateral dimensions in other directions were more difficult to correct for disorder but appeared to be 3 nm or less. However for cherry and sunflower, the microfibril spacing estimated by SANS was about 4 nm and was insensitive to the presence of moisture. If the microfibril width was 3 nm as estimated by WAXS, the SANS spacing suggests that a non-cellulosic polymer segment might in places separate the aggregated cellulose microfibrils

    A class of quadratic deformations of Lie superalgebras

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    We study certain Z_2-graded, finite-dimensional polynomial algebras of degree 2 which are a special class of deformations of Lie superalgebras, which we call quadratic Lie superalgebras. Starting from the formal definition, we discuss the generalised Jacobi relations in the context of the Koszul property, and give a proof of the PBW basis theorem. We give several concrete examples of quadratic Lie superalgebras for low dimensional cases, and discuss aspects of their structure constants for the `type I' class. We derive the equivalent of the Kac module construction for typical and atypical modules, and a related direct construction of irreducible modules due to Gould. We investigate in detail one specific case, the quadratic generalisation gl_2(n/1) of the Lie superalgebra sl(n/1). We formulate the general atypicality conditions at level 1, and present an analysis of zero-and one-step atypical modules for a certain family of Kac modules.Comment: 26pp, LaTeX. Original title: "Finite dimensional quadratic Lie superalgebras"; abstract re-worded; text clarified; 3 references added; rearrangement of minor appendices into text; new subsection 4.

    A Cross-Sectional Analysis of Green Space Prevalence and Mental Wellbeing in England

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    Background With urbanisation increasing, it is important to understand how to design changing environments to promote mental wellbeing. Evidence suggests that local-area proportions of green space may be associated with happiness and life satisfaction; however, the available evidence on such associations with more broadly defined mental wellbeing in still very scarce. This study aimed to establish whether the amount of neighbourhood green space was associated with mental wellbeing. Methods Data were drawn from Understanding Society, a national survey of 30,900 individuals across 11,096 Census Lower-Layer Super Output Areas (LSOAs) in England, over the period 2009–2010. Measures included the multi-dimensional Warwick-Edinburgh Mental Well-Being Scale (SWEMWBS) and LSOA proportion of green space, which was derived from the General Land Use Database (GLUD), and were analysed using linear regression, while controlling for individual, household and area-level factors. Results Those living in areas with greater proportions of green space had significantly higher mental wellbeing scores in unadjusted analyses (an expected increase of 0.17 points (95% CI 0.11, 0.23) in the SWEMWBS score for a standard deviation increase of green space). However, after adjustment for confounding by respondent sociodemographic characteristics and urban/rural location, the association was attenuated to the null (regression coefficient B = − 0.01, 95% CI -0.08, 0.05, p = 0.712). Conclusions While the green space in an individual’s local area has been shown through other research to be related to aspects of mental health such as happiness and life satisfaction, the association with multidimensional mental wellbeing is much less clear from our results. While we did not find a statistically significant association between the amount of green space in residents’ local areas and mental wellbeing, further research is needed to understand whether other features of green space, such as accessibility, aesthetics or use, are important for mental wellbeing

    Evidence that the AGN dominates the radio emission in z ~ 1 radio-quiet quasars

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    This document is the Accepted Manuscript version of the following article: Sarah V. White, Matt J. Jarvis, Eleni Kalfoutnzou, Martin J. Hardcastle, Aprajita Verma, Mose M. Cao Orjales, and Jason Stevens, 'Evidence that the AGN dominates the radio emission in z ~ 1 radio quiet quasars', Monthly Notices of the Royal Astronomical Society, first published online 3 February 2017, DOI: https://doi.org/10.1093/mnras/stx284 Key results are presented in Table 4 and Figure 7, which illustrates where the RQQs lie in relation to the far-infrared--radio correlation © 2017 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society.In order to understand the role of radio-quiet quasars (RQQs) in galaxy evolution, we must determine the relative levels of accretion and star-formation activity within these objects. Previous work at low radio flux-densities has shown that accretion makes a significant contribution to the total radio emission, in contrast with other quasar studies that suggest star formation dominates. To investigate, we use 70 RQQs from the Spitzer-Herschel Active Galaxy Survey. These quasars are all at zz ~ 1, thereby minimising evolutionary effects, and have been selected to span a factor of ~100 in optical luminosity, so that the luminosity dependence of their properties can be studied. We have imaged the sample using the Karl G. Jansky Very Large Array (JVLA), whose high sensitivity results in 35 RQQs being detected above 2 σ\sigma. This radio dataset is combined with far-infrared luminosities derived from grey-body fitting to Herschel photometry. By exploiting the far-infrared--radio correlation observed for star-forming galaxies, and comparing two independent estimates of the star-formation rate, we show that star formation alone is not sufficient to explain the total radio emission. Considering RQQs above a 2-σ\sigma detection level in both the radio and the far-infrared, 92 per cent are accretion-dominated, and the accretion process accounts for 80 per cent of the radio luminosity when summed across the objects. The radio emission connected with accretion appears to be correlated with the optical luminosity of the RQQ, whilst a weaker luminosity-dependence is evident for the radio emission connected with star formation.Peer reviewedFinal Accepted Versio

    The clustering and bias of radio-selected AGN and star-forming galaxies in the COSMOS field

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    Dark matter haloes in which galaxies reside are likely to have a significant impact on their evolution. We investigate the link between dark matter haloes and their constituent galaxies by measuring the angular two-point correlation function of radio sources, using recently released 3 GHz imaging over $\sim 2 \ \mathrm{deg}^2oftheCOSMOSfield.WesplittheradiosourcepopulationintoStarFormingGalaxies(SFGs)andActiveGalacticNuclei(AGN),andfurtherseparatetheAGNintoradiativelyefficientandinefficientaccreters.Restrictingouranalysisto of the COSMOS field. We split the radio source population into Star Forming Galaxies (SFGs) and Active Galactic Nuclei (AGN), and further separate the AGN into radiatively efficient and inefficient accreters. Restricting our analysis to z<1,wefindSFGshaveabias,, we find SFGs have a bias, b = 1.5 ^{+0.1}_{-0.2},atamedianredshiftof, at a median redshift of z=0.62.Ontheotherhand,AGNaresignificantlymorestronglyclusteredwith. On the other hand, AGN are significantly more strongly clustered with b = 2.1\pm 0.2atamedianredshiftof0.7.ThissupportstheideathatAGNarehostedbymoremassivehaloesthanSFGs.Wealsofindlow−accretionrateAGNaremoreclustered( at a median redshift of 0.7. This supports the idea that AGN are hosted by more massive haloes than SFGs. We also find low-accretion rate AGN are more clustered (b = 2.9 \pm 0.3)thanhigh−accretionrateAGN() than high-accretion rate AGN (b = 1.8^{+0.4}_{-0.5})atthesameredshift() at the same redshift (z \sim 0.7),suggestingthatlow−accretionrateAGNresideinhighermasshaloes.ThissupportspreviousevidencethattherelativelyhotgasthatinhabitsthemostmassivehaloesisunabletobeeasilyaccretedbythecentralAGN,causingthemtobeinefficient.Wealsofindevidencethatlow−accretionrateAGNappeartoresideinhalomassesof), suggesting that low-accretion rate AGN reside in higher mass haloes. This supports previous evidence that the relatively hot gas that inhabits the most massive haloes is unable to be easily accreted by the central AGN, causing them to be inefficient. We also find evidence that low-accretion rate AGN appear to reside in halo masses of M_{h} \sim 3-4 \times 10^{13}h^{-1}MM_{\odot}atallredshifts.Ontheotherhand,theefficientaccretersresideinhaloesof at all redshifts. On the other hand, the efficient accreters reside in haloes of M_{h} \sim 1-2 \times 10^{13}h^{-1}MM_{\odot}atlowredshiftbutcanresideinrelativelylowermasshaloesathigherredshifts.Thiscouldbeduetotheincreasedprevalenceofcoldgasinlowermasshaloesat at low redshift but can reside in relatively lower mass haloes at higher redshifts. This could be due to the increased prevalence of cold gas in lower mass haloes at z \ge 1comparedto compared to z<1$.Comment: 20 pages, 10 figures, 1 table, accepted by MNRA

    An Exploratory Study of Extended Health Care Practitioner Roles in Medication Supply and Management in a Rural Community

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    Australia has a recognised shortage of qualified health professionals, particularly in rural and regional areas. Research has shown that rural patients indeed have poorer health status compared to metropolitan communities, with rates of mortality and morbidity constantly higher in rural regions. A number of ‘novel’ and ‘extended’ roles have been developed for existing health care professionals. Some of these roles have application to rural areas, such as additional functions in terms of provision of medicines. In Queensland in particular, the Health (Drugs and Poisons) Regulation 1996 (the Regulation), which provides the regulatory framework for the handling of medicines, has been amended to include a range of endorsements, including Indigenous Health Workers (IHW) and Rural and Isolated Practice-endorsed Nurses (RIPRN). Another development is the amendment of the Regulation to allow for a range of health professionals, namely optometrists, physicians’ assistants and nurse practitioners, to prescribe medicines. Whether such developments have addressed the needs of rural communities remains unknown. Inherently, rural communities will suffer from limited access to health care services, and the services of the existing health care providers may be stretched to, or beyond, the scope of their recognised practice in order to meet the needs of the community. Little is known about the extent and nature of these ‘extended’ practices, the perceived need for (or obligation on) health professionals to adopt these roles, and the ethical, professional and legal considerations if/when they extend their services into non-traditional territories. This research specifically focussed on the involvement of various health care providers in patients’ medication management in a defined community or region. In doing so, it aimed to identify medication-related issues of a community and the potential roles for pharmacists to enhance safe, effective and efficient access to medicines in a rural setting.Griffith Health, School of PharmacyFull Tex
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