156 research outputs found

    Development of a silicon vertex tracker for the electron-ion collider

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    The electron-ion collider (EIC) will be built at the Brookhaven National Laboratory over the next ten years, with the purpose of giving insight into nucleon structure, origins of nucleon mass and spin, and quark and gluon confinement. This thesis pertains to the silicon vertex tracker for an EIC experiment; the detector closest to the interaction point. The purpose of a silicon vertex tracker is to locate the origin vertex position of charged particles and measure the particle momentum, and the EIC physics goals require detector resolutions beyond current state-of-the-art silicon vertex trackers. The aim of this thesis is to find a suitable silicon sensor technology for further developments by tests performed in a lab and at a testbeam, and to find a silicon vertex tracker geometry with performance matching the EIC physics requirements using simulations. The baseline sensor for the studies comes from the ALICE inner tracker upgrade, and is called the ALPIDE sensor. A new monolithic silicon sensor development designed to increase depletion is tested and compared to the performance of an ALPIDE-like sensor, and found to improve charge collection performance while keeping the sensor capacitance low. This aids tracking performance, and the new development is thus considered a possible path for development of an EIC-specific sensor. Simulations of different silicon vertex tracker geometries and parameters are performed using GEANT4, and a high-performing layout consisting of inner and outer silicon sensor layers surrounded by a gaseous detector and silicon disks is developed. It is also found that if a more compact tracker is desired, an all-silicon concept outperforms a combination of silicon and gaseous detectors. Further simulations of the best-performing layouts with current projections of possible silicon sensor material thickness and pixel size show that they meet the requirements of the EIC physics goals in terms of momentum resolution if a 3 T solenoidal magnetic field is used, and pointing resolution regardless of magnetic field strength. The silicon vertex tracker developed in this work is one of two baseline tracker concepts used in the ongoing development of an EIC reference detector. The performance of different detector concepts is also studied using realistic electron-proton collision events generated using PYTHIA and propagated through the detector simulation, with a focus on charmed meson reconstruction. It is found that a compact all-silicon tracker can perform as well as an all-silicon concept with a larger radius in these studies, but a large-radius combination of silicon and gaseous detectors is always better than all-silicon concepts in the studied open charm case

    Plasma 1-carbon metabolites and academic achievement in 15-yr-old adolescents

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    Academic achievement in adolescents is correlated with 1-carbon metabolism (1-CM), as folate intake is positively related and total plasma homocysteine (tHcy) negatively related to academic success. Because another 1-CM nutrient, choline is essential for fetal neurocognitive development, we hypothesized that choline and betaine could also be positively related to academic achievement in adolescents. In a sample of 15-yr-old children (n = 324), we measured plasma concentrations of homocysteine, choline, and betaine and genotyped them for 2 polymorphisms with effects on 1-CM, methylenetetrahydrofolate reductase (MTHFR) 677C>T, rs1801133, and phosphatidylethanolamine N-methyltransferase (PEMT), rs12325817 (G>C). The sum of school grades in 17 major subjects was used as an outcome measure for academic achievement. Lifestyle and family socioeconomic status (SES) data were obtained from questionnaires. Plasma choline was significantly and positively associated with academic achievement independent of SES factors (paternal education and income, maternal education and income, smoking, school) and of folate intake (P = 0.009, R2 = 0.285). With the addition of the PEMT rs12325817 polymorphism, the association value was only marginally changed. Plasma betaine concentration, tHcy, and the MTHFR 677C>T polymorphism did not affect academic achievement in any tested model involving choline. Dietary intake of choline is marginal in many adolescents and may be a public health concern

    The complexities of communication at hospital discharge of older patients: a qualitative study of healthcare professionals' views

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    BACKGROUND: Hospital discharge of older patients is a high-risk situation in terms of patient safety. Due to the fragmentation of the healthcare system, communication and coordination between stakeholders are required at discharge. The aim of this study was to explore communication in general and medication information transfer in particular at hospital discharge of older patients from the perspective of healthcare professionals (HCPs) across different organisations within the healthcare system. METHODS: We conducted a qualitative study using focus group and individual or group interviews with HCPs (physicians, nurses and pharmacists) across different healthcare organisations in Sweden. Data were collected from September to October 2021. A semi-structured interview guide including questions on current medication communication practices, possible improvements and feedback on suggestions for alternative processes was used. The data were analysed thematically, guided by the systematic text condensation method. RESULTS: In total, four focus group and three semi-structured interviews were conducted with 23 HCPs. Three main themes were identified: 1) Support systems that help and hinder describes the use of support systems in the discharge process to compensate for the fragmentation of the healthcare system and the impact of these systems on HCPs' communication; 2) Communication between two separate worlds depicts the difficulties in communication experienced by HCPs in different healthcare organisations and how they cope with them; and 3) The large number of medically complex patients disrupts the communication reveals how the highly pressurised healthcare system impacts on HCPs' communication at hospital discharge. CONCLUSIONS: Communication at hospital discharge is hindered by the fragmented, highly pressurised healthcare system. HCPs are at risk of moral distress when coping with communication difficulties. Improved communication methods at hospital discharge are needed for the benefit of both patients and HCPs

    Associations between insulin and glucose concentrations and anthropometric measures of fat mass in Australian adolescents

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    <p>Abstract</p> <p>Background</p> <p>One of the most serious, yet common co-morbidities of obesity is insulin resistance, which if untreated may progress to type 2 diabetes. This paper describes the insulin and glucose concentration distributions, the prevalence of elevated insulin, the associations between insulin and body mass index (BMI), waist circumference, waist-to-height ratio (WHtR) and fat mass index in a representative sample of Australian adolescents.</p> <p>Methods</p> <p>Cross-sectional population-based study of adolescent boys and girls (N = 496, mean age 15.3 years) attending schools in metropolitan Sydney, Australia. Fasting venous blood collected and analysed for insulin and glucose concentrations. Height, weight, waist circumference measured, BMI and waist-to-height ratio calculated. Pubertal status self-reported.</p> <p>Results</p> <p>Glucose concentrations were normally distributed and were not associated with adiposity. Insulin concentrations were distributed logarithmically, were higher among girls than boys overall and within the same ranges of BMI and waist circumference, but were lower among girls than boys within the same ranges of fat mass adjusted for height. The prevalence of elevated insulin concentration (defined as > 100 pmol/L) was 15.9% and 17.1% among boys and girls, respectively. Correlations between insulin concentration and BMI, waist circumference, WHtR and fat mass adjusted for height were 0.53, 0.49, 0.51 and 0.55, among boys, respectively, and 0.35, 0.40, 0.42 and 0.34, among girls, respectively.</p> <p>Conclusions</p> <p>Elevated insulin is highly correlated with adiposity in adolescents. BMI and WHtR are simple measures that can be used to identify young people who should be screened for insulin resistance and other co-morbidities.</p

    Developing a Monolithic Silicon Sensor in a 65 nm CMOS Imaging Technology for Future Lepton Collider Vertex Detectors

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    Monolithic CMOS sensors in a 65 nm imaging technology are being investigated by the CERN EP Strategic R&D Programme on Technologies for Future Experiments for an application in particle physics. The appeal of monolithic detectors lies in the fact that both sensor volume and readout electronics are integrated in the same silicon wafer, providing a reduction in production effort, costs and scattering material. The Tangerine Project WP1 at DESY participates in the Strategic R&D Programme and is focused on the development of a monolithic active pixel sensor with a time and spatial resolution compatible with the requirements for a future lepton collider vertex detector. By fulfilling these requirements, the Tangerine detector is suitable as well to be used as telescope planes for the DESY-II Test Beam facility. The project comprises all aspects of sensor development, from the electronics engineering and the sensor design using simulations, to laboratory and test beam investigations of prototypes. Generic TCAD Device and Monte-Carlo simulations are used to establish an understanding of the technology and provide important insight into performance parameters of the sensor. Testing prototypes in laboratory and test beam facilities allows for the characterization of their response to different conditions. By combining results from all these studies it is possible to optimize the sensor layout. This contribution presents results from generic TCAD and Monte-Carlo simulations, and measurements performed with test chips of the first sensor submission.Comment: 7 pages, 8 figures, submitted to IEEE Xplore as conference record for 2022 IEEE NSS/MIC/RTS

    TAxonomy of Self-reported Sedentary behaviour Tools (TASST) framework for development, comparison and evaluation of self-report tools:content analysis and systematic review

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    OBJECTIVE: Sedentary behaviour (SB) has distinct deleterious health outcomes, yet there is no consensus on best practice for measurement. This study aimed to identify the optimal self-report tool for population surveillance of SB, using a systematic framework. DESIGN: A framework, TAxonomy of Self-reported Sedentary behaviour Tools (TASST), consisting of four domains (type of assessment, recall period, temporal unit and assessment period), was developed based on a systematic inventory of existing tools. The inventory was achieved through a systematic review of studies reporting SB and tracing back to the original description. A systematic review of the accuracy and sensitivity to change of these tools was then mapped against TASST domains. DATA SOURCES: Systematic searches were conducted via EBSCO, reference lists and expert opinion. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: The inventory included tools measuring SB in adults that could be self-completed at one sitting, and excluded tools measuring SB in specific populations or contexts. The systematic review included studies reporting on the accuracy against an objective measure of SB and/or sensitivity to change of a tool in the inventory. RESULTS: The systematic review initially identified 32 distinct tools (141 questions), which were used to develop the TASST framework. Twenty-two studies evaluated accuracy and/or sensitivity to change representing only eight taxa. Assessing SB as a sum of behaviours and using a previous day recall were the most promising features of existing tools. Accuracy was poor for all existing tools, with underestimation and overestimation of SB. There was a lack of evidence about sensitivity to change. CONCLUSIONS: Despite the limited evidence, mapping existing SB tools onto the TASST framework has enabled informed recommendations to be made about the most promising features for a surveillance tool, identified aspects on which future research and development of SB surveillance tools should focus. TRIAL REGISTRATION NUMBER: International prospective register of systematic reviews (PROPSPERO)/CRD42014009851

    Different healthy habits between northern and southern Spanish school children

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    Aim: Healthy habits are influenced by several factors such as, geographical location. The aims of this study were to describe and compare healthy habits within two populations of sixth-grade primary school children (aged 11-12 years) from Northern and Southern Spain. Subject and Methods: A cross-sectional study using two representative samples of school children was conducted. Participants came from Logroño (n=329), in the North and Granada (n=284), in the South of Spain. Socio-demographic and anthropometric variables, adherence to the Mediterranean diet, aerobic fitness, and healthy lifestyles were recorded. Results: Boys reported higher level of physical activity and aerobic fitness than girls (p=0.000). Southern school children reported significantly higher adherence to the Mediterranean diet (♀: p=0.041; ♂: p=0.008), and lower aerobic fitness (♀: p=0.000; ♂: p=0.042) and hours of nightly sleep (♀: p=0.008, ♂: p=0.007) than Northern school children. Southern boys also reported lower levels of physical activity (p=0.013). There were slight or moderate correlations among all habits measured (physical activity, diet, screen and sleep time). Additionally, physical activity level was inversely related to body mass index in Northern boys (p=0.020) and Southern girls (p=0.024). Conclusions: Results showed differences in physical activity, eating and sleep habits, and aerobic fitness, according to geographical location. The relationships found among lifestyle habits indicate the need of health promotion interventions nationally and considering the differences discussed here

    Home-based health promotion for older people with mild frailty: the HomeHealth intervention development and feasibility RCT.

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    BACKGROUND: Mild frailty or pre-frailty is common and yet is potentially reversible. Preventing progression to worsening frailty may benefit individuals and lower health/social care costs. However, we know little about effective approaches to preventing frailty progression. OBJECTIVES: (1) To develop an evidence- and theory-based home-based health promotion intervention for older people with mild frailty. (2) To assess feasibility, costs and acceptability of (i) the intervention and (ii) a full-scale clinical effectiveness and cost-effectiveness randomised controlled trial (RCT). DESIGN: Evidence reviews, qualitative studies, intervention development and a feasibility RCT with process evaluation. INTERVENTION DEVELOPMENT: Two systematic reviews (including systematic searches of 14 databases and registries, 1990-2016 and 1980-2014), a state-of-the-art review (from inception to 2015) and policy review identified effective components for our intervention. We collected data on health priorities and potential intervention components from semistructured interviews and focus groups with older people (aged 65-94 years) (n = 44), carers (n = 12) and health/social care professionals (n = 27). These data, and our evidence reviews, fed into development of the 'HomeHealth' intervention in collaboration with older people and multidisciplinary stakeholders. 'HomeHealth' comprised 3-6 sessions with a support worker trained in behaviour change techniques, communication skills, exercise, nutrition and mood. Participants addressed self-directed independence and well-being goals, supported through education, skills training, enabling individuals to overcome barriers, providing feedback, maximising motivation and promoting habit formation. FEASIBILITY RCT: Single-blind RCT, individually randomised to 'HomeHealth' or treatment as usual (TAU). SETTING: Community settings in London and Hertfordshire, UK. PARTICIPANTS: A total of 51 community-dwelling adults aged ≥ 65 years with mild frailty. MAIN OUTCOME MEASURES: Feasibility - recruitment, retention, acceptability and intervention costs. Clinical and health economic outcome data at 6 months included functioning, frailty status, well-being, psychological distress, quality of life, capability and NHS and societal service utilisation/costs. RESULTS: We successfully recruited to target, with good 6-month retention (94%). Trial procedures were acceptable with minimal missing data. Individual randomisation was feasible. The intervention was acceptable, with good fidelity and modest delivery costs (£307 per patient). A total of 96% of participants identified at least one goal, which were mostly exercise related (73%). We found significantly better functioning (Barthel Index +1.68; p = 0.004), better grip strength (+6.48 kg; p = 0.02), reduced psychological distress (12-item General Health Questionnaire -3.92; p = 0.01) and increased capability-adjusted life-years [+0.017; 95% confidence interval (CI) 0.001 to 0.031] at 6 months in the intervention arm than the TAU arm, with no differences in other outcomes. NHS and carer support costs were variable but, overall, were lower in the intervention arm than the TAU arm. The main limitation was difficulty maintaining outcome assessor blinding. CONCLUSIONS: Evidence is lacking to inform frailty prevention service design, with no large-scale trials of multidomain interventions. From stakeholder/public perspectives, new frailty prevention services should be personalised and encompass multiple domains, particularly socialising and mobility, and can be delivered by trained non-specialists. Our multicomponent health promotion intervention was acceptable and delivered at modest cost. Our small study shows promise for improving clinical outcomes, including functioning and independence. A full-scale individually RCT is feasible. FUTURE WORK: A large, definitive RCT of the HomeHealth service is warranted. STUDY REGISTRATION: This study is registered as PROSPERO CRD42014010370 and Current Controlled Trials ISRCTN11986672. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 73. See the NIHR Journals Library website for further project information

    Relationship between self-reported dietary intake and physical activity levels among adolescents: The HELENA study

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    Background Evidence suggests possible synergetic effects of multiple lifestyle behaviors on health risks like obesity and other health outcomes. Therefore it is important to investigate associations between dietary and physical activity behavior, the two most important lifestyle behaviors influencing our energy balance and body composition. The objective of the present study is to describe the relationship between energy, nutrient and food intake and the physical activity level among a large group of European adolescents. Methods The study comprised a total of 2176 adolescents (46.2% male) from ten European cities participating in the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study. Dietary intake and physical activity were assessed using validated 24-h dietary recalls and self-reported questionnaires respectively. Analyses of covariance (ANCOVA) were used to compare the energy and nutrient intake and the food consumption between groups of adolescents with different physical activity levels (1st to 3rd tertile). Results In both sexes no differences were found in energy intake between the levels of physical activity. The most active males showed a higher intake of polysaccharides, protein, water and vitamin C and a lower intake of saccharides compared to less active males. Females with the highest physical activity level consumed more polysaccharides compared to their least active peers. Male and female adolescents with the highest physical activity levels, consumed more fruit and milk products and less cheese compared to the least active adolescents. The most active males showed higher intakes of vegetables and meat, fish, eggs, meat substitutes and vegetarian products compared to the least active ones. The least active males reported the highest consumption of grain products and potatoes. Within the female group, significantly lower intakes of bread and cereal products and spreads were found for those reporting to spend most time in moderate to vigorous physical activity. The consumption of foods from the remaining food groups, did not differ between the physical activity levels in both sexes. Conclusion It can be concluded that dietary habits diverge between adolescents with different self-reported physical activity levels. For some food groups a difference in intake could be found, which were reflected in differences in some nutrient intakes. It can also be concluded that physically active adolescents are not always inclined to eat healthier diets than their less active peers.The HELENA study took place with the financial support of the European Community Sixth RTD Framework Programme (Contract FOOD-CT: 2005-007034). This work was also partially supported by the European Union, in the framework of the Public Health Programme (ALPHA project, Ref: 2006120), the Swedish Council for Working Life and Social Research (FAS), the Spanish Ministry of Education (EX-2007-1124, and EX-2008-0641), and the Spanish Ministry of Health, Maternal, Child Health and Development Network (number RD08/0072) (JPRL, LAM)

    Ideal cardiovascular health and inflammation in European adolescents: The HELENA study

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    Background and aims Inflammation plays a key role in atherosclerosis and this process seems to appear in childhood. The ideal cardiovascular health index (ICHI) has been inversely related to atherosclerotic plaque in adults. However, evidence regarding inflammation and ICHI in adolescents is scarce. The aim is to assess the association between ICHI and inflammation in European adolescents. Methods and results As many as 543 adolescents (251 boys and 292 girls) from the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study, a cross-sectional multi-center study including 9 European countries, were measured. C-reactive protein (CRP), complement factors C3 and C4, leptin and white blood cell counts were used to compute an inflammatory score. Multilevel linear models and multilevel logistic regression were used to assess the association between ICHI and inflammation controlling by covariates. Higher ICHI was associated with a lower inflammatory score, as well as with several individual components, both in boys and girls (p < 0.01). In addition, adolescents with at least 4 ideal components of the ICHI had significantly lower inflammatory score and lower levels of the study biomarkers, except CRP. Finally, the multilevel logistic regression showed that for every unit increase in the ICHI, the probability of having an inflammatory profile decreased by 28.1% in girls. Conclusion Results from this study suggest that a better ICHI is associated with a lower inflammatory profile already in adolescence. Improving these health behaviors, and health factors included in the ICHI, could play an important role in CVD prevention
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