18 research outputs found

    Smectic blue phases: layered systems with high intrinsic curvature

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    We report on a construction for smectic blue phases, which have quasi-long range smectic translational order as well as three dimensional crystalline order. Our proposed structures fill space by adding layers on top of a minimal surface, introducing either curvature or edge defects as necessary. We find that for the right range of material parameters, the favorable saddle-splay energy of these structures can stabilize them against uniform layered structures. We also consider the nature of curvature frustration between mean curvature and saddle-splay.Comment: 15 pages, 11 figure

    Search for Fingerprints of Tetrahedral Symmetry in 156Gd^{156}Gd

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    Theoretical predictions suggest the presence of tetrahedral symmetry as an explanation for the vanishing intra-band E2-transitions at the bottom of the odd-spin negative parity band in 156Gd^{156}Gd. The present study reports on experiment performed to address this phenomenon. It allowed to determine the intra-band E2 transitions and branching ratios B(E2)/B(E1) of two of the negative-parity bands in 156Gd^{156}Gd.Comment: presented by Q.T. Doan at XLII Zakopane School of Physics: Breaking Frontiers: Submicron Structures in Physics and Biology, May 2008. 5 pages, minor corrections. To be published in the proceeding

    Effect and process evaluation of a kindergarten-based, family-involved cluster randomised controlled trial in six European countries on four- to six-year-old children's steps per day: The ToyBox-study

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    Background: The ToyBox-intervention is a theory- and evidence-based intervention delivered in kindergartens to improve four- to six-year-old children''s energy balance-related behaviours and prevent obesity. The current study aimed to (1) examine the effect of the ToyBox-intervention on increasing European four- to six-year-old children'' steps per day, and (2) examine if a higher process evaluation score from teachers and parents was related to a more favourable effect on steps per day. Methods: A sample of 2438 four- to six-year-old children (51.9% boys, mean age 4.75±0.43years) from 6 European countries (Belgium, Bulgaria, Germany, Greece, Poland and Spain) wore a motion sensor (pedometer or accelerometer) for a minimum of two weekdays and one weekend day both at baseline and follow-up to objectively measure their steps per day. Kindergarten teachers implemented the physical activity component of the ToyBox-intervention for 6 weeks in total, with a focus on (1) environmental changes in the classroom, (2) the child performing the actual behaviour and (3) classroom activities. Children''s parents received newsletters, tip cards and posters. To assess intervention effects, multilevel repeated measures analyses were conducted for the total sample and the six intervention countries separately. In addition, process evaluation questionnaires were used to calculate a total process evaluation score (with implementation and satisfaction as a part of the overall score) for teachers and parents which was then linked with the physical activity outcomes. Results: No significant intervention effects on four- to six-year-old children'' steps per weekday, steps per weekend day and steps per average day were found, both in the total sample and in the country-specific samples (all p>0.05). In general, the intervention effects on steps per day were least favourable in four- to six-year-old children with a low teachers process evaluation score and most favourable in four- to six-year-old children with a high teachers process evaluation score. No differences in intervention effects were found for a low, medium or high parents'' process evaluation score. Conclusion: The physical activity component of the ToyBox-intervention had no overall effect on four- to six-year-old children'' steps per day. However, the process evaluation scores showed that kindergarten teachers that implemented the physical activity component of the ToyBox-intervention as planned and were satisfied with the physical activity component led to favourable effects on children''s steps per day. Strategies to motivate, actively involve and engage the kindergarten teachers and parents/caregivers are needed to induce larger effects

    Worldwide comparison of survival from childhood leukaemia for 1995–2009, by subtype, age, and sex (CONCORD-2): a population-based study of individual data for 89 828 children from 198 registries in 53 countries

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    Background Global inequalities in access to health care are reflected in differences in cancer survival. The CONCORD programme was designed to assess worldwide differences and trends in population-based cancer survival. In this population-based study, we aimed to estimate survival inequalities globally for several subtypes of childhood leukaemia. Methods Cancer registries participating in CONCORD were asked to submit tumour registrations for all children aged 0-14 years who were diagnosed with leukaemia between Jan 1, 1995, and Dec 31, 2009, and followed up until Dec 31, 2009. Haematological malignancies were defined by morphology codes in the International Classification of Diseases for Oncology, third revision. We excluded data from registries from which the data were judged to be less reliable, or included only lymphomas, and data from countries in which data for fewer than ten children were available for analysis. We also excluded records because of a missing date of birth, diagnosis, or last known vital status. We estimated 5-year net survival (ie, the probability of surviving at least 5 years after diagnosis, after controlling for deaths from other causes [background mortality]) for children by calendar period of diagnosis (1995-99, 2000-04, and 2005-09), sex, and age at diagnosis (< 1, 1-4, 5-9, and 10-14 years, inclusive) using appropriate life tables. We estimated age-standardised net survival for international comparison of survival trends for precursor-cell acute lymphoblastic leukaemia (ALL) and acute myeloid leukaemia (AML). Findings We analysed data from 89 828 children from 198 registries in 53 countries. During 1995-99, 5-year agestandardised net survival for all lymphoid leukaemias combined ranged from 10.6% (95% CI 3.1-18.2) in the Chinese registries to 86.8% (81.6-92.0) in Austria. International differences in 5-year survival for childhood leukaemia were still large as recently as 2005-09, when age-standardised survival for lymphoid leukaemias ranged from 52.4% (95% CI 42.8-61.9) in Cali, Colombia, to 91.6% (89.5-93.6) in the German registries, and for AML ranged from 33.3% (18.9-47.7) in Bulgaria to 78.2% (72.0-84.3) in German registries. Survival from precursor-cell ALL was very close to that of all lymphoid leukaemias combined, with similar variation. In most countries, survival from AML improved more than survival from ALL between 2000-04 and 2005-09. Survival for each type of leukaemia varied markedly with age: survival was highest for children aged 1-4 and 5-9 years, and lowest for infants (younger than 1 year). There was no systematic difference in survival between boys and girls. Interpretation Global inequalities in survival from childhood leukaemia have narrowed with time but remain very wide for both ALL and AML. These results provide useful information for health policy makers on the effectiveness of health-care systems and for cancer policy makers to reduce inequalities in childhood survival

    Process evaluation design and tools used in a kindergarten-based, family-involved intervention to prevent obesity in early childhood. The ToyBox-study

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    Process evaluation (PE) is used for the in-depth evaluation of the implementation process of health promotion programmes. The aim of the current paper was to present the PE design and tools used in the ToyBox-intervention. The PE design was based on a three-step approach, including the identification of ToyBox-specific PE elements (step 1), the development of PE tools and harmonization of procedures (step 2), and the implementation of PE using standardized protocol and tools across the intervention countries (step 3). Specifically, to evaluate the implementation of the intervention, teachers\u27 monthly logbooks were recorded (dose delivered, fidelity, dose received); post-intervention questionnaires were completed by parents/caregivers and teachers (dose received); participation and attrition rates were recorded (recruitment, reach); and audit questionnaires and retrospective information on weather conditions were collected (physical and social environment within which the intervention was implemented). Regarding the teachers\u27 training sessions, the researchers who performed the trainings completed evaluation forms and documented teachers\u27 attendance after each training (dose delivered, fidelity, dose received) and teachers completed evaluation forms after each training (dose received). The PE performed in the ToyBox-intervention may contribute in the evaluation of its effectiveness, guide the revision of the intervention material and provide insights for future health promotion programmes and public health policy

    CityGML Application Domain Extension (ADE): overview of developments

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    The Application Domain Extension (ADE) is a built-in mechanism of CityGML to augment its data model with additional concepts required by particular use cases. The goal of this paper is to provide an overview of the ADE mechanism and a literature review of developments since its introduction a decade ago. The discovery of publications found that currently there are 44 ADEs supporting a wide range of applications, but also application-agnostic purposes such as harmonisation with national geographic information standards. We hope this paper to double as a reference material for the developers of new ADEs.Urban Data Scienc

    Interaction of Particles and Pathogens with Biological Membranes

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    Biological membranes are both barriers and communication interfaces of cells. Transport across membranes is therefore essential for life. It encompasses both endocytotic and exocytotic processes important for cell function, but also the invasion of cells by parasites and viruses, and targeted drug delivery. Whereas interactions on the molecular scale are important for particles with sizes comparable with the thickness of the membrane, the mechanical properties of the entire membrane determine its interaction with larger particles. We focus here on large particles and parasites and discuss wrapping of single particles by homogeneous and complex membranes. Both solid particles with various shapes as well as soft particles are considered. Membrane-mediated interactions of many particles lead to aggregation and tubulation. Finally, active biological mechanisms are shown to support the invasion of parasites, such as the malaria parasite, and to drive phagocytosis

    Prospective BMI changes in preschool children are not effected by changes in EBRBs but by parental characteristics and body weight perceptions: The ToyBox-study.

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    Objective: To examine the effect of the intervention implemented in the ToyBox study on changes observed in age and sex specific BMI percentile and investigate the role of perinatal factors, parental perceptions and characteristics on this change. Design: A multicomponent, kindergarten-based, family-involved intervention with a cluster-randomized design. A standardized protocol was used to measure children’s body weight and height. Information was also collected from parents/caregivers via the use of validated questionnaires. Linear mixed effect models with random intercept for country, socioeconomic status and school were used. Setting: Selected preschools within the provinces of Oost-Flanders and West-Flanders (Belgium), Varna (Bulgaria), Bavaria (Germany), Attica (Greece), Mazowieckie (Poland) and Zaragoza (Spain). Participants: A sample of 6, 268 pre-schoolers aged 3.5-5.5 (51.9% boys). Results: There was no intervention effect on the change in children’s BMI percentile. However, parents’ underestimation of their children’s actual weight status, parental overweight and mothers’ pre-pregnancy overweight/obesity were found to be significantly and independently associated with increases in children’s BMI percentile in multivariate modelling. Conclusion: Before or as part of the implementation of any childhood obesity intervention initiative, it is important to assist parents/caregivers to correctly perceive their own and their children’s weight status. Recognition of excessive weight by parents/caregivers can increase their readiness to change and as such facilitate higher adherence to favourable behavioural changes within the family. © 2021 Lippincott Williams and Wilkins. All rights reserved
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