63 research outputs found

    Patterns of coronary heart disease mortality over the 20th century in England and Wales: Possible plateaus in the rate of decline

    Get PDF
    BackgroundCoronary heart disease (CHD) rates in England and Wales between 1950 and 2005 were high and reasonably steady until the mid 1970s, when they began to fall. Recent work suggests that the rate of change in some groups has begun to decrease and may be starting to plateau or even reverse.MethodsData for all deaths between 1931 and 2005 in England and Wales were grouped by year, sex, age at death and contemporaneous ICD code for CHD as cause of death. CHD mortality rates by calendar year and birth cohort were produced for both sexes and rates of change were examined.ResultsThe pattern of increased burden of CHD mortality within older age groups has only recently emerged in men, whereas it has been established in women for far longer. CHD mortality rates among younger people showed little variation by birth cohort. For younger women (49 and under), the rate of change in CHD mortality has reversed in the last 20 years, indicating a future plateau and possible reversal of previous improvement in CHD mortality rates. Among younger men the rate of change in CHD mortality has been consistent for the past 15 years indicating that rates in this group have continued to fall steadily.ConclusionAlthough CHD mortality rates continue to drop in older age groups the actual burden of coronary heart disease is increasing due to the ageing of the population. The rate of improvement in CHD mortality appears to be beginning to decline and may even be reversing among younger women.<br /

    Electronic structure of superconducting graphite intercalate compounds: The role of the interlayer state

    Full text link
    Although not an intrinsic superconductor, it has been long--known that, when intercalated with certain dopants, graphite is capable of exhibiting superconductivity. Of the family of graphite--based materials which are known to superconduct, perhaps the most well--studied are the alkali metal--graphite intercalation compounds (GIC) and, of these, the most easily fabricated is the C8{}_8K system which exhibits a transition temperature Tc≃0.14\bm{T_c\simeq 0.14} K. By increasing the alkali metal concentration (through high pressure fabrication techniques), the transition temperature has been shown to increase to as much as 5\bm 5 K in C2{}_2Na. Lately, in an important recent development, Weller \emph{et al.} have shown that, at ambient conditions, the intercalated compounds \cyb and \cca exhibit superconductivity with transition temperatures Tc≃6.5\bm{T_c\simeq 6.5} K and 11.5\bm{11.5} K respectively, in excess of that presently reported for other graphite--based compounds. We explore the architecture of the states near the Fermi level and identify characteristics of the electronic band structure generic to GICs. As expected, we find that charge transfer from the intercalant atoms to the graphene sheets results in the occupation of the π\bm\pi--bands. Yet, remarkably, in all those -- and only those -- compounds that superconduct, we find that an interlayer state, which is well separated from the carbon sheets, also becomes occupied. We show that the energy of the interlayer band is controlled by a combination of its occupancy and the separation between the carbon layers.Comment: 4 Figures. Please see accompanying experimental manuscript "Superconductivity in the Intercalated Graphite Compounds C6Yb and C6Ca" by Weller et a

    Social Class Differences in Secular Trends in Established Coronary Risk Factors over 20 Years: A Cohort Study of British Men from 1978–80 to 1998–2000

    Get PDF
    Background: Coronary heart disease (CHD) mortality in the UK since the late 1970s has declined more markedly among higher socioeconomic groups. However, little is known about changes in coronary risk factors in different socioeconomic groups. This study examined whether changes in established coronary risk factors in Britain over 20 years between 1978-80 and 1998-2000 differed between socioeconomic groups.Methods and Findings: A socioeconomically representative cohort of 7735 British men aged 40-59 years was followed-up from 1978-80 to 1998-2000; data on blood pressure (BP), cholesterol, body mass index (BMI) and cigarette smoking were collected at both points in 4252 survivors. Social class was based on longest-held occupation in middle-age. Compared with men in non-manual occupations, men in manual occupations experienced a greater increase in BMI (mean difference=0.33 kg/m(2); 95%CI 0.14-0.53; p for interaction=0.001), a smaller decline in non-HDL cholesterol (difference in mean change=0.18 mmol/l; 95%CI 0.11-0.25, p for interaction <= 0.0001) and a smaller increase in HDL cholesterol (difference in mean change=0.04 mmol/l; 95%CI 0.02-0.06, p for interaction <= 0.0001). However, mean systolic BP declined more in manual than non-manual groups (difference in mean change=3.6; 95%CI 2.1-5.1, p for interaction <= 0.0001). The odds of being a current smoker in 1978-80 and 1998-2000 did not differ between non-manual and manual social classes (p for interaction = 0.51).Conclusion: Several key risk factors for CHD and type 2 diabetes showed less favourable changes in men in manual occupations. Continuing priority is needed to improve adverse cardiovascular risk profiles in socially disadvantaged groups in the UK

    Temporal variations of vegetative features, sex ratios and reproductive phenology in a Dictyota dichotoma (Dictyotales, Phaeophyceae) population of Argentina

    Get PDF
    This paper addresses the phenology of a Dictyota dichotoma population from the North Patagonian coasts of Argentina. The morphology of the individuals was characterized, and analyses of the temporal variations of vegetative features, diploid and haploid life cycle generations and sex ratios are provided. Individuals, represented by growing sporophytes and gametophytes, occurred simultaneously throughout the year. Morphological variables showed temporal variation, except the width and height of medullary cells, which did not vary between seasons. All vegetative variables were significantly correlated with daylength. Besides, frond length, frond dry mass and apical and basal branching angles were significantly correlated with seawater temperatures. Vegetative thalli were less abundant than haploid and diploid thalli. Sporophytes were less abundant than male and female gametophytes. Male gametophytes dominated in May, August, October and January, and female gametophytes were more abundant in September, November, December, February and March. The formation of female gametangia showed a significant correlation with daylength, and the highest number of gametangia was registered in spring. In general, the male/female sex ratio varied between 1:2 and 1:1. Apical regions were more fertile than basal regions. Our data about frequency in the formation of reproductive structures and male/female ratios are the first recorded in the Dictyota genus and thus could not be compared with populations from other regions of the world. Significant morphological variation was observed in thalli of both life cycle generations, regarding length and dry mass, number of primary branches and branching basal angle. In general, all variables analyzed varied seasonally except cortical cell width.Fil: Gauna, Maria Cecilia. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Ecología Acuática; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto Argentino de Oceanografía (i); ArgentinaFil: Caceres, Eduardo Jorge. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Ficología y Micología; ArgentinaFil: Parodi, Elisa Rosalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto Argentino de Oceanografía (i); Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Ecología Acuática; Argentin

    IPP-rich milk protein hydrolysate lowers blood pressure in subjects with stage 1 hypertension, a randomized controlled trial

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Milk derived peptides have been identified as potential antihypertensive agents. The primary objective was to investigate the effectiveness of IPP-rich milk protein hydrolysates (MPH) on reducing blood pressure (BP) as well as to investigate safety parameters and tolerability. The secondary objective was to confirm or falsify ACE inhibition as the mechanism underlying BP reductions by measuring plasma renin activity and angiotensin I and II.</p> <p>Methods</p> <p>We conducted a randomized, placebo-controlled, double blind, crossover study including 70 Caucasian subjects with prehypertension or stage 1 hypertension. Study treatments consisted of daily consumption of two capsules MPH1 (each containing 7.5 mg Isoleucine-Proline-Proline; IPP), MPH2 (each containing 6.6 mg Methionine-Alanine-Proline, 2.3 mg Leucine-Proline-Proline, 1.8 mg IPP), or placebo (containing cellulose) for 4 weeks.</p> <p>Results</p> <p>In subjects with stage 1 hypertension, MPH1 lowered systolic BP by 3.8 mm Hg (P = 0.0080) and diastolic BP by 2.3 mm Hg (P = 0.0065) compared with placebo. In prehypertensive subjects, the differences in BP between MPH1 and placebo were not significant. MPH2 did not change BP significantly compared with placebo in stage I hypertensive or prehypertensive subjects. Intake of MPHs was well tolerated and safe. No treatment differences in hematology, clinical laboratory parameters or adverse effects were observed. No significant differences between MPHs and placebo were found in plasma renin activity, or angiotensin I and II.</p> <p>Conclusions</p> <p>MPH1, containing IPP and no minerals, exerts clinically relevant BP lowering effects in subjects with stage 1 hypertension. It may be included in lifestyle changes aiming to prevent or reduce high BP.</p> <p>Trial registration</p> <p>ClinicalTrials.gov NCT00471263</p

    Neighborhood fast food restaurants and fast food consumption: A national study

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Recent studies suggest that neighborhood fast food restaurant availability is related to greater obesity, yet few studies have investigated whether neighborhood fast food restaurant availability promotes fast food consumption. Our aim was to estimate the effect of neighborhood fast food availability on frequency of fast food consumption in a national sample of young adults, a population at high risk for obesity.</p> <p>Methods</p> <p>We used national data from U.S. young adults enrolled in wave III (2001-02; ages 18-28) of the National Longitudinal Study of Adolescent Health (n = 13,150). Urbanicity-stratified multivariate negative binomial regression models were used to examine cross-sectional associations between neighborhood fast food availability and individual-level self-reported fast food consumption frequency, controlling for individual and neighborhood characteristics.</p> <p>Results</p> <p>In adjusted analysis, fast food availability was not associated with weekly frequency of fast food consumption in non-urban or low- or high-density urban areas.</p> <p>Conclusions</p> <p>Policies aiming to reduce neighborhood availability as a means to reduce fast food consumption among young adults may be unsuccessful. Consideration of fast food outlets near school or workplace locations, factors specific to more or less urban settings, and the role of individual lifestyle attitudes and preferences are needed in future research.</p

    The associations between sedentary behaviour and mental health among adolescents:A systematic review

    Get PDF
    Background: With technological developments and modernised sedentary lifestyles has come an increase in diseases associated with inactivity such as obesity and other non-communicable diseases. Emerging evidence suggests that time spent sedentary may also interact with mental health. This systematic review examined the associations between sedentary behaviour and mental health problems among adolescents. Methods: This systematic review followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses, and applied a quality assessment tool for quantitative studies to identity best available evidence. Following stringent search strategy of the databases; Cumulative Index to Nursing and Allied Health Literature, Global Health, Health Source: Nursing and Academic Edition, MEDLINE, PsychARTICLES and PsycINFO, we identified 32 articles eligible for review. Results: All studies reported leisure screen time among adolescents, and two thirds of identified studies examined depressive symptomatology. Other mental health measures were; anxiety symptoms, self-esteem, suicide ideation, loneliness, stress, and psychological distress. Strong consistent evidence was found for the relationship between both depressive symptomatology and psychological distress, and time spent using screens for leisure. Moderate evidence supported the relationship between low self-esteem and screen use. Poorer mental health status was found among adolescents using screen time more than 2-3 h per day, and gender differences exist. Essential information was missing for quality of evidence including heterogeneity in mental health and screen time-based measures, and self-report data collection methods. Conclusions: The findings are of particular significance given the global public health concern of lifestyle-attributed diseases and the possibility for novel approaches to mental health. Future research should examine the psychological impact of reducing time spent using screens for leisure among adolescents, whilst accounting for possible confounding factors such as physical activity and dietary behaviours. It is critical that the reciprocal relationship between lifestyle behaviours and mental health is represented in both the psychiatric and public health forum

    Current influences and approaches to promote future physical activity in 11–13 year olds: a focus group study

    Get PDF
    BACKGROUND: Many children and adolescents are failing to meet current physical activity (PA) guidelines and consequently not achieving the benefits associated with regular participation in PA, with girls consistently less active than boys. In order to design interventions to increase physical activity in adolescents it is important to understand their perceptions of and preferences for physical activity. METHODS: One hundred eighty participants, mean (SD) age 12.1 (0.5) years, completed the Physical Activity Questionnaire for Children (PAQ-C) and had height and weight measured. This information was used to select a subsample of participants (n64; mean (SD) age 12.3 (0.4) years; 39 females; 25 males; 25 % overweight/obese) to take part in focus group discussions. Participants were grouped based on PAQ-C responses into ‘low-active’ and ‘highly-active’ groups, so that those with similar existing levels of PA were in the same focus group. A semi-structured discussion guide was employed to explore the key influences on current PA participation and to actively seek ideas on how best to promote future PA in this population. In total, nine focus groups (mixed-gender) were conducted within the school setting. All focus groups were audio recorded, transcribed verbatim and analysed thematically. RESULTS: A number of themes emerged in relation to influences on current PA including friendship and peers, family and other people, the consequences of not taking part in PA, changing priorities, and cost and access to resources. With regards to the future provision of PA, participants favoured opportunities to try new activities, increased provision of school-based activities which can be undertaken with friends and activities which incorporated the use of technology and encouragement through rewards and incentives. Gender differences were apparent in relation to the types of activities participants preferred taking part in. Differences were also observed between ‘low-active’ and ‘highly-active’ groups in relation to barriers to current participation in PA. CONCLUSIONS: This study has highlighted a number of influences on current and future participation in PA, which differed based on gender and existing PA levels, for example, maximising the potential of the school day and including technology and incentives. These components can inform targeted interventions to increase PA in low active adolescents

    Monitoring activities of teenagers to comprehend their habits: study protocol for a mixed-methods cohort study

    Get PDF
    Abstract: Background: Efforts to increase physical activity in youth need to consider which activities are most likely to be sustained over time in order to promote lifelong participation in physical activity. The Monitoring Activities of Teenagers to Comprehend their Habits (MATCH) study is a prospective cohort study that uses quantitative and qualitative methods to develop new knowledge on the sustainability of specific physical activities. Methods/design: Eight hundred and forty-three grade 5 and 6 students recruited from 17 elementary schools in New Brunswick, Canada, are followed-up three times per year. At each survey cycle, participants complete self-report questionnaires in their classroom under the supervision of trained data collectors. A sub-sample of 24 physically active students is interviewed annually using a semi-structured interview protocol. Parents (or guardians) complete telephone administered questionnaires every two years, and a health and wellness school audit is completed for each school. Discussion: MATCH will provide a description of the patterns of participation in specific physical activities in youth, and enable identification of the determinants of maintenance, decline, and uptake of participation in each activity. These data will inform the development of interventions that take into account which activities are the most likely to be maintained and why activities are maintained or dropped
    • …
    corecore