111,195 research outputs found

    Development of the children's eating behaviour questionnaire

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    Individual differences in several aspects of eating style have been implicated in the development of weight problems in children and adults, but there are presently no reliable and valid scales that assess a range of dimensions of eating style. This paper describes the development and preliminary validation of a parent-rated instrument to assess eight dimensions of eating style in children; the Children's Eating Behaviour Questionnaire (CEBQ). Constructs for inclusion were derived both from the existing literature on eating behaviour in children and adults, and from interviews with parents. They included reponsiveness to food, enjoyment of food, satiety responsiveness, slowness in eating, fussiness, emotional overeating, emotional undereating, and desire for drinks. A. large pool of items covering each of these: constructs was developed. The number of items was then successively culled through analysis of responses from three samples of families of young children (N = 131; N = 187, N = 218), to produce a 35-item instrument with eight scales which were internally valid and had good test-retest reliability. Investigation of variations by gender and age revealed only minimal gender differences in any aspect of eating style. Satiety responsiveness and slowness in eating diminished from age 3 to 8. Enjoyment of food and food responsiveness increased over this age range. The CEBQ should provide a useful measure of eating style for research into the early precursors of obesity or eating disorders. This is especially important in relation to the growing evidence for the heritability of obesity, where good measurement of the associated behavioural phenotype will be crucial in investigating the contribution of inherited variations in eating behaviour to the process of weight gain

    The importance of electron temperature in silicon-based terahertz quantum cascade lasers

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    Quantum cascade lasers (QCLs) are compact sources of coherent terahertz radiation. Although all existing QCLs use III-V compound semiconductors, silicon-based devices are highly desirable due to the high thermal conductivity and mature processing technology. We use a semiclassical rate-equation model to show that Ge/SiGe THz QCL active region gain is strongly enhanced by reducing the electron temperature. We present a bound-to-continuum QCL design employing L-valley intersubband transitions, using high Ge fraction barriers to reduce interface roughness scattering, and a low electric field to reduce the electron temperature. We predict a gain of similar to 50 cm(-1), which exceeds the calculated waveguide losses. (C) 2009 American Institute of Physics. [doi: 10.1063/1.3237177

    Prevalence of asymptomatic malaria and bed net ownership and use in Bhutan, 2013: a country earmarked for malaria elimination

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    BACKGROUND With dwindling malaria cases in Bhutan in recent years, the government of Bhutan has made plans for malaria elimination by 2016. This study aimed to determine coverage, use and ownership of LLINs, as well as the prevalence of asymptomatic malaria at a single time-point, in four sub-districts of Bhutan. METHODS A cross-sectional study was carried out in August 2013. Structured questionnaires were administered to a single respondent in each household (HH) in four sub-districts. Four members from 25 HH, randomly selected from each sub-district, were tested using rapid diagnostic tests (RDT) for asymptomatic Plasmodium falciparum and Plasmodium vivax infection. Multivariable logistic regression models were used to identify factors associated with LLIN use and maintenance. RESULTS All blood samples from 380 participants tested negative for Plasmodium infections. A total of 1,223 HH (92.5% of total HH) were surveyed for LLIN coverage and use. Coverage of LLINs was 99.0% (1,203/1,223 HH). Factors associated with decreased odds of sleeping under a LLIN included: washing LLINs nine months compared to washing LLINs every six months; HH in the least poor compared to the most poor socio-economic quintile; a HH income of Nu 5,001-10,000 (US$1 = Nu 59.55), and Nu >10,000, compared to HH with income of <Nu 1,500; HH located one to three hours walking distance to a health centre compared to being located closer to a health centre; a reported lack of knowledge as to what to do in event of LLINs being torn; and keeping LLINs in a box compared to keeping them hanging in the place of use. Factors associated with use of LLINs for purposes other than the intended use included: income group Nu 1,501-3,000 and HH located one to three hours walking distance from a health centre. CONCLUSIONS There was high coverage of LLINs in the study area with regular use of LLINs throughout the year. LLIN use for purposes other than malaria prevention was low. With high coverage and regular use of LLINs, and a zero prevalence of malaria infection found in historically high-risk communities during the peak malaria season, it appears Bhutan is on course to achieve malaria elimination.We acknowledge Queensland Infectious Disease Unit for providing funds to carry out this study

    The Stratigraphic Record of Pre-breakup Geodynamics: Evidence from the Barrow Delta, offshore Northwest Australia

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    The structural and stratigraphic evolution of rift basins and passive margins has been widely studied, with many analyses demonstrating that delta systems can provide important records of post-rift geodynamic processes. However, the apparent lack of ancient syn-breakup delta systems and the paucity of seismic imaging across continent-ocean boundaries means the transition from continental rifting to oceanic spreading remains poorly understood. The Early Cretaceous Barrow Group of the North Carnarvon Basin, offshore NW Australia was a major deltaic system that formed during the latter stages of continental rifting, and represents a rich sedimentary archive, documenting uplift, subsidence and erosion of the margin. We use a regional database of 2D and 3D seismic and well data to constrain the internal architecture of the Barrow Group. Our results highlight three major depocentres: the Exmouth and Barrow sub-basins, and southern Exmouth Plateau. Over-compaction of pre-Cretaceous sedimentary rocks in the South Carnarvon Basin, and pervasive reworking of Permian and Triassic palynomorphs in the offshore Barrow Group, suggests that the onshore South Carnarvon Basin originally contained a thicker sedimentary succession, which was uplifted and eroded prior to breakup. Backstripping of sedimentary successions encountered in wells in the Exmouth Plateau depocentre indicate anomalously rapid tectonic subsidence (≤0.24 mm yr-1) accommodated Barrow Group deposition, despite evidence for minimal, contemporaneous upper crustal extension. Our results suggest that classic models of uniform extension cannot account for the observations of uplift and subsidence in the North Carnarvon Basin, and may indicate a period of depth-dependent extension or dynamic topography preceding breakup

    Modelling of gypsum and ice diapirs in the martian crust

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    Complementary techniques of percutaneous closure of ductus arteriosus using detachable cook coils and amplatzer devices

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    Background: Patent Ductus Arteriosus (PDA) is a common cardiac malformation whose treatment locally has been surgical ligation via a lateral thoracotomy. Device closure of the ductus was first performed at the Mater hospital in 1999 in a ten year old male using a five millilitre detachable cook coil. In 2000 the Amplatzer device was introduced to close larger ducts. Subsequently these devices have been used interchangeably to close both small and large ducts. We report this single centre experience of percutaneous PDA closure in a resource-limited setting; utilising the two techniques.Objective: To describe our experience of trans-catheter closure of small and large ducts using either the detachable Cook coils or the Amplatzer occluders at the Mater Hospital Nairobi.Design: A descriptive retrospective cohort study.Setting: The Mater Hospital, Nairobi, Kenya.Subjects: Patients with clinical and echo-cardiographic features of patent ductus arteriosus who underwent cardiac catheterisation and angiography followed by device embolisation of the ductus.Results: From April 1999 to October 2009 a total of ninety eight subjects were recruited into the study. Sixty nine (70%) of these subjects had the ducts closed using the Amplatzer devices, while twenty nine (30%) were embolised using the cook detachable coils. Three of the subjects in the coil group had the ducts embolised using the double technique while the rest were embolised using single coils. Various coil sizes four to eight millimetres were used in patients with small to medium ducts (two to seven millimetres) whereas the Amplatzer duct occluder was successfully used in all the duct sizes. The Amplatzer atrial septal occluder device was used to close very large ducts in two of the patients. The overall success rate was 93.1%, but the coil group had higher failure rate of 6.9% compared to the  Amplatzer group of 3%. One patient in the Amplatzer group had a late embolisation requiring surgical retrieval at one month post occlusion. There were no mortalities.Conclusion: Transcatheter device occlusion of PDA is a safe and alternative to surgery associated with minimal morbidity and no mortalit
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