962 research outputs found

    Conclusion of Viking Lander Imaging Investigation: Picture catalog of experiment data record

    Get PDF
    The images returned by the two Viking landers during the Viking Survey Mission are presented in this report. Listing of supplemental information which describe the conditions under which the images were acquired are included. Subsets of the images are listed in a variety of sequences to aid in locating images of interest. The format and organization of the digital magnetic tape storage of the images are described. A brief description of the mission and the camera system is also included

    Accidental consumption of aspartame in phenylketonuria: patient experiences

    Get PDF
    Aspartame is a phenylalanine containing sweetener, added to foods and drinks, which is avoided in phenylketonuria (PKU). However, the amount of phenylalanine provided by aspartame is unidentifiable from food and drinks labels. We performed a cross-sectional online survey aiming to examine the accidental aspartame consumption in PKU. 206 questionnaires (58% female) were completed. 55% of respondents (n = 114) were adults with PKU or their parent/carers and 45% (n = 92) were parents/carers of children with PKU. 74% (n = 152/206) had consumed food/drinks containing aspartame. Repeated accidental aspartame consumption was common and more frequent in children (p 0.0001). The aspartame containing food/drinks accidentally consumed were fizzy drinks (68%, n = 103/152), fruit squash (40%, n = 61/152), chewing gum (30%, n = 46/152), flavoured water (25%, n = 38/152), ready to drink fruit squash cartons (23%, n = 35/152) and sports drinks (21%, n = 32/152). The main reasons described for accidental consumption, were manufacturers’ changing recipes (81%, n = 123/152), inability to check the ingredients in pubs/restaurants/vending machines (59%, n = 89/152) or forgetting to check the label (32%, n = 49/152). 23% (n= 48/206) had been prescribed medicines containing aspartame and 75% (n = 36/48) said that medicines were not checked by medics when prescribed. 85% (n = 164/192) considered the sugar tax made accidental aspartame consumption more likely. Some of the difficulties for patients were aspartame identification in drinks consumed in restaurants, pubs, vending machines (77%, n = 158/206); similarities in appearance of aspartame and non-aspartame products (62%, n = 127/206); time consuming shopping/checking labels (56%, n = 115/206); and unclear labelling (55%, n = 114/206). These issues caused anxiety for the person with PKU (52%, n = 106/206), anxiety for parent/caregivers (46%, n = 95/206), guilt for parent/carers (42%, n = 87/206) and social isolation (42%, n = 87/206). It is important to understand the impact of aspartame and legislation such as the sugar tax on people with PKU. Policy makers and industry should ensure that the quality of life of people with rare conditions such as PKU is not compromised through their action

    Thirty Years of Precision Electroweak Physics

    Get PDF
    We discuss the development of the theory of electroweak radiative corrections and its role in testing the Standard Model, predicting the top quark mass, constraining the Higgs boson mass, and searching for deviations that may signal the presence of new physics.Comment: 19 pages, acknowledgments added, J.J.Sakurai Prize Talk, APS Meeting, Albuquerque, N.M., April 2002. To appear in a future issue of Journal of Physics

    Hungry for change: the experiences of people with PKU, and their caregivers, when eating out

    Get PDF
    For patients with phenylketonuria (PKU), stringent dietary management is demanding and eating out may pose many challenges. Often, there is little awareness about special dietary requirements within the hospitality sector. This study’s aim was to investigate the experiences and behaviours of people with PKU and their caregivers when dining out. We also sought to identify common problems in order to improve their experiences when eating outside the home. Individuals with PKU or their caregivers residing in the UK were invited to complete a cross-sectional online survey that collected both qualitative and quantitative data about their experiences when eating out. Data were available from 254 questionnaire respondents (136 caregivers or patients with PKU 18 years and 118 patients with PKU ≥ 18 years (n = 100) or their caregivers (n = 18)). Fifty-eight per cent dined out once per month or less (n = 147/254) and the biggest barrier to more frequent dining was ‘limited choice of suitable low-protein foods’ (90%, n = 184/204), followed by ‘no information about the protein content of foods’ (67%, n = 137/204). Sixty-nine per cent (n = 176/254) rated their dining experience as less than satisfactory. Respondents ranked restaurant employees’ knowledge of the PKU diet as very poor with an overall median rating of 1.6 (on a scale of 1 for extremely poor to 10 for extremely good). Forty-four per cent (n = 110/252) of respondents said that restaurants had refused to prepare alternative suitable foods; 44% (n = 110/252) were not allowed to eat their own prepared food in a restaurant, and 46% (n = 115/252) reported that restaurants had refused to cook special low-protein foods. Forty per cent (n = 101/254) of respondents felt anxious before entering restaurants. People with PKU commonly experienced discrimination in restaurants, with hospitality staff failing to support their dietary needs, frequently using allergy laws and concerns about cross-contamination as a reason not to provide suitable food options. It is important that restaurant staff receive training regarding low-protein diets, offer more low-protein options, provide protein analysis information on all menu items, and be more flexible in their approach to cooking low-protein foods supplied by the person with PKU. This may help people with PKU enjoy safe meals when dining out and socialising with others

    Provision and supervision of food and protein substitute in school for children with PKU: parent experiences

    Get PDF
    Children spend a substantial part of their childhood in school, so provision of dietary care and inclusion of children with phenylketonuria (PKU) in this setting is essential. There are no reports describing the dietary support children with PKU receive whilst at school. The aim of this cross-sectional study was to explore the experiences of the dietary management of children with PKU in schools across the UK. Data was collected using an online survey completed by parents/caregivers of children with PKU. Of 159 questionnaire responses, 92% (n = 146) of children attended state school, 6% (n = 10) private school and 2% (n = 3) other. Fourteen per cent (n = 21/154) were at nursery/preschool, 51% (n = 79/154) primary and 35% (n = 54/154) secondary school. Sixty-one per cent (n = 97/159) said their child did not have school meals, with some catering services refusing to provide suitable food and some parents distrusting the school meals service. Sixty-one per cent of children had an individual health care plan (IHCP) (n = 95/155). Children were commonly unsupervised at lunchtime (40%, n = 63/159), with snacks (46%, n = 71/155) and protein substitute (30%, n = 47/157), with significantly less supervision in secondary than primary school (p 0.001). An IHCP was significantly associated with improved supervision of food and protein substitute administration (p 0.01), and better communication between parents/ caregivers and the school team (p 0.05). Children commonly accessed non-permitted foods in school. Therefore, parents/caregivers described important issues concerning the school provision of low phenylalanine food and protein substitute. Every child should have an IHCP which details their dietary needs and how these will be met safely and discreetly. It is imperative that children with PKU are supported in school

    Dietary nitrate increases arginine availability and protects mitochondrial complex I and energetics in the hypoxic rat heart

    Get PDF
    This is the final version. It was first published by Wiley in The Journal of Physiology at http://onlinelibrary.wiley.com/doi/10.1113/jphysiol.2014.275263/abstract.Hypoxic exposure is associated with impaired cardiac energetics in humans and altered mitochondrial function, with suppressed complex I-supported respiration, in rat heart. This response might limit reactive oxygen species (ROS) generation, but at the cost of impaired electron transport chain (ETC) activity. Dietary nitrate supplementation improves mitochondrial efficiency and can promote tissue oxygenation by enhancing blood flow. We therefore hypothesised that ETC dysfunction, impaired energetics and oxidative damage in the hearts of rats exposed to chronic hypoxia could be alleviated by sustained administration of a moderate dose of dietary nitrate. Male Wistar rats (n=40) were given water supplemented with 0.7 mmol/L NaCl (as control) or 0.7 mmol/L NaNO3, elevating plasma nitrate levels by 80%, and were exposed to 13% O2 (hypoxia) or normoxia (n=10 per group) for 14 days. Respiration rates, ETC protein levels, mitochondrial density, ATP content and protein carbonylation were measured in cardiac muscle. Complex I respiration rates and protein levels were 33% lower in hypoxic/NaCl rats compared with normoxic/NaCl controls. Protein carbonylation was 65% higher in hearts of hypoxic rats compared with controls, indicating increased oxidative stress, whilst ATP levels were 62% lower. Respiration rates, complex I protein and activity, protein carbonylation and ATP levels were all fully protected in the hearts of nitrate-supplemented hypoxic rats. Both in normoxia and hypoxia, dietary nitrate suppressed cardiac arginase expression and activity and markedly elevated cardiac L-arginine concentrations, unmasking a novel mechanism of action by which nitrate enhances tissue NO bioavailability. Dietary nitrate therefore alleviates metabolic abnormalities in the hypoxic heart, improving myocardial energetics

    Pyramidal micromirrors for microsystems and atom chips

    Get PDF
    Concave pyramids are created in the (100) surface of a silicon wafer by anisotropic etching in potassium hydroxide. High quality micromirrors are then formed by sputtering gold onto the smooth silicon (111) faces of the pyramids. These mirrors show great promise as high quality optical devices suitable for integration into micro-optoelectromechanical systems and atom chips. We have shown that structures of this shape can be used to laser-cool and hold atoms in a magneto-optical trap

    Two-Loop Bhabha Scattering in QED

    Full text link
    In the context of pure QED, we obtain analytic expressions for the contributions to the Bhabha scattering differential cross section at order alpha^4 which originate from the interference of two-loop photonic vertices with tree-level diagrams and from the interference of one-loop photonic diagrams amongst themselves. The ultraviolet renormalization is carried out. The IR-divergent soft-photon emission corrections are evaluated and added to the virtual cross section. The cross section obtained in this manner is valid for on-shell electrons and positrons of finite mass, and for arbitrary values of the center of mass energy and momentum transfer. We provide the expansion of our results in powers of the electron mass, and we compare them with the corresponding expansion of the complete order alpha^4 photonic cross section, recently obtained in hep-ph/0501120. As a by-product, we obtain the contribution to the Bhabha scattering differential cross section of the interference of the two-loop photonic boxes with the tree-level diagrams, up to terms suppressed by positive powers of the electron mass. We evaluate numerically the various contributions to the cross section, paying particular attention to the comparison between exact and expanded results.Comment: 35 pages, 18 figure

    Maternal outcomes in subsequent delivery after previous obstetric anal sphincter injury (OASI): a multi-centre retrospective cohort study.

    Get PDF
    INTRODUCTION AND HYPOTHESIS: Women with a history of obstetric anal sphincter injury (OASI) are at increased risk of recurrence (rOASI) at subsequent delivery; however, evidence regarding the factors influencing this risk is limited. Furthermore, little is known about what factors influence the decision to alternatively deliver by elective caesarean section (ELLSCS). METHODS: Retrospective univariate and multivariate logistic regression analysis of prospectively collected data from four NHS electronic maternity databases including primiparous women sustaining OASIS during a singleton, term, cephalic, vaginal delivery between 2004 and 2015, who had a subsequent delivery. RESULTS: Two thousand two hundred seventy-two women met the criteria; 10.2% delivering vaginally had a repeat OASI and 59.4% had a second-degree tear. Women having an ELLSCS were more likely to be Caucasian, older, have previously had an operative vaginal delivery (OVD) and have a more severe degree of OASI. Positive predictors for rOASI were increased birth weight and maternal age at both index and subsequent deliveries, a more severe degree of initial OASI and Asian ethnicity. The overall mediolateral episiotomy (MLE) rate was 15.6%; 77.2% of those who had an episiotomy sustained no spontaneous perineal trauma. Only 4.4% of women with a rOASI had an MLE, whilst the MLE rate was 16.9% in those without a recurrence (p  4 kg increased the risk 2.5 fold. CONCLUSIONS: Women with previous OASIS are at an increased risk of recurrence. A more liberal use of MLE during subsequent vaginal delivery could significantly reduce the risk of recurrence

    Decays of Scalar and Pseudoscalar Higgs Bosons into Fermions: Two-loop QCD Corrections to the Higgs-Quark-Antiquark Amplitude

    Full text link
    As a first step in the aim of arriving at a differential description of neutral Higgs boson decays into heavy quarks, hQQˉXh \to Q {\bar Q}X, to second order in the QCD coupling αS\alpha_S, we have computed the hQQˉhQ{\bar Q} amplitude at the two-loop level in QCD for a general neutral Higgs boson which has both scalar and pseudoscalar couplings to quarks. This amplitude is given in terms of a scalar and a pseudoscalar vertex form factor, for which we present closed analytic expressions in terms of one-dimensional harmonic polylogarithms of maximum weight 4. The results hold for arbitrary four-momentum squared, q2q^2, of the Higgs boson and of the heavy quark mass, mm. Moreover we derive the approximate expressions of these form factors near threshold and in the asymptotic regime m2/q21m^2/q^2 \ll 1.Comment: 56 pages, 2 figure
    corecore