4,750 research outputs found

    Bed and Breakfast: The Role of Sleep in Breakfast Intake

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    Breakfast intake is associated with numerous positive physical and mental health outcomes, yet skipping breakfast remains common in adults. Sleep behaviors show potential as predictors of breakfast intake; the existing literature, however, has methodological limitations. The current investigation explored the association of means and intraindividual variability of a variety of sleep behaviors (bedtime, midsleep, sleep duration) as predictors of the frequency of eating breakfast and frequency of high-protein breakfast intake. Hierarchical regressions were conducted to assess direct associations between sleep behaviors and breakfast intake frequency. Variability in bedtime was a significant predictor of the frequency of breakfast intake, with greater variability associated with less frequent intake. Variability in sleep duration and midsleep was not significant predictors of the frequency of breakfast intake. Both variability and mean sleep behaviors were not significant predictors of the frequency of breakfast intake or high-protein breakfast intake. Because greater regularity in bedtimes was associated with more frequent breakfast intake, it is plausible that there should be increased education regarding the importance of regularity of sleep behaviors

    Effectiveness and reach of a directed-population approach to improving dental health and reducing inequalities: a cross sectional study

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    Background Childsmile School adopts a directed-population approach to target fluoride varnish applications to 20% of the primary one (P1) population in priority schools selected on the basis of the proportion of enrolled children considered to be at increased-risk of developing dental caries. The study sought to compare the effectiveness of four different methods for identifying individuals most in need when a directed-population approach is taken. <p></p> Methods The 2008 Basic National Dental Inspection Programme (BNDIP) cross-sectional P1 Scottish epidemiological survey dataset was used to model four methods and test three definitions of increased-risk. Effectiveness was determined by the positive predictive value (PPV) and explored in relation to 1-sensitivity and 1-specificity. <p></p> Results Complete data was available on 43470 children (87% of the survey). At the Scotland level, at least half (50%) of the children targeted were at increased-risk irrespective of the method used to target or the definition of increased-risk. There was no one method across all definitions of <i>increased-risk</i> that maximised PPV. Instead, PPV was highest when the targeting method complimented the definition of <i>increased-risk</i>. There was a higher percentage of children at <i>increased-risk</i> who were not targeted (1-sensitivity) when caries experience (rather than deprivation) was used to define <i>increased-risk</i>, irrespective of the method used for targeting. Over all three definitions of <i>increased-risk</i>, there was no one method that minimised (1-sensitivity) although this was lowest when the method and definition of <i>increased-risk</i> were complimentary. The false positive rate (1-specificity) for all methods and all definitions of <i>increased-risk</i> was consistently low (<20%), again being lowest when the method and definition of <i>increased-risk</i> were complimentary. <p></p> Conclusion Developing a method to reach all (or even the vast majority) of individuals at <i>increased-risk</i> defined by either caries experience or deprivation is difficult using a directed-population approach at a group level. There is a need for a wider debate between politicians and public health experts to decide how best to reach those most at need of intervention to improve health and reduce inequalities. <p></p&gt

    The kaolinitic clay deposits on Beaconsfield, north of Grahamstown

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    The Grahamstown clay deposits occur below the Grahamstown Formation silcrete, which forms a remnant of an extensive peneplain that developed on the African erosion surface during the Cretaceous–Tertiary period. This paper provides new data on the distribution of the kaolinitic clay deposits in the Beaconsfield area north of Grahamstown. These data include 23 borehole profiles through the deposits, and the chemistry and mineralogy of the clays. Relatively little information is available on this part of the peneplain. It was found that the thickness of the kaolin horizon varies considerably, but reaches 35m in places. It generally occurs under a silcrete cover, which attains a thickness of 8 m in places. Lithological logs enable direct comparison across the Beaconsfield area. The clays are developed in both the Witteberg Group shale and Dwyka Group tillite. The contact between the clay and underlying bedrock is gradational and relatively uneven. Major-element X-ray fluorescence analyses revealed that there is chemical variation, both vertically and laterally. Al2O3 content is generally near 20%, but may reach 29%. SiO2 content varies between 55 and 70+%. SiO2 contents are highest in the silcretes occurring just below soil level. Fe2O3 is high locally in the top part of the profile. K2O and Na2O are generally low, but increase towards the unweathered bedrock as the primary feldspar content increases. These compositional variations are compatible with residual concentrations of kaolinitic clays through deep weathering below the former African erosion surface

    Advanced electrostatic ion thruster for space propulsion

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    The suitability of the baseline 30 cm thruster for future space missions was examined. Preliminary design concepts for several advanced thrusters were developed to assess the potential practical difficulties of a new design. Useful methodologies were produced for assessing both planetary and earth orbit missions. Payload performance as a function of propulsion system technology level and cost sensitivity to propulsion system technology level are among the topics assessed. A 50 cm diameter thruster designed to operate with a beam voltage of about 2400 V is suggested to satisfy most of the requirements of future space missions

    An optical fibre dynamic instrumented palpation sensor for the characterisation of biological tissue

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    AbstractThe diagnosis of prostate cancer using invasive techniques (such as biopsy and blood tests for prostate-specific antigen) and non-invasive techniques (such as digital rectal examination and trans-rectal ultrasonography) may be enhanced by using an additional dynamic instrumented palpation approach to prostate tissue classification. A dynamically actuated membrane sensor/actuator has been developed that incorporates an optical fibre Fabry–Pérot interferometer to record the displacement of the membrane when it is pressed on to different tissue samples. The membrane sensor was tested on a silicon elastomer prostate model with enlarged and stiffer material on one side to simulate early stage prostate cancer. The interferometer measurement was found to have high dynamic range and accuracy, with a minimum displacement resolution of ±0.4μm over a 721μm measurement range. The dynamic response of the membrane sensor when applied to different tissue types changed depending on the stiffness of the tissue being measured. This demonstrates the feasibility of an optically tracked dynamic palpation technique for classifying tissue type based on the dynamic response of the sensor/actuator

    Redressing the balance: Commentary on “Examining motor learning in older adults using analogy instruction” by Tse, Wong, and Masters (2017)

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    Tse, Wong, and Masters (2017) recently published a study that indicated that analogy instruction may help older adults acquire resilient motor skills that require reduced cognitive processing compared to traditional explicit instruction. Although we do not dispute that analogy learning may prove useful for this population, in this commentary, we contend that there are methodological issues in this research—which are shared with previous studies comparing analogy and explicit instruction—that potentially limit ecological validity, impact the size of detected effects, influence the development and understanding of associated theory, and, as such, constrain resulting recommendations for applied practice. Of particular concern is the comparison of the single-item analogy instruction to the list of nine explicit instructions, which risks conflating the effects of the type of instruction with the volume of instruction. We further argue that the benefits of analogy may be more parsimoniously explained by the instruction’s capability to succinctly convey skill (rather than its potential for limiting reinvestment), but that this capability may only be realised if the to-be-learned analogy is relevant and readily understood by the learner. Finally, we suggest that research in this area must look to incorporate more rigorous methods that compare experimental conditions to representative reference groups that allow us to explore how and when to deploy the myriad instructional tools available to practitioners and learners

    Performance of formulae based estimates of glomerular filtration rate for carboplatin dosing in stage 1 seminoma

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    <b>Background:</b> Single cycle carboplatin, dosed by glomerular filtration rate (GFR), is standard adjuvant therapy for stage 1 seminoma. Accurate measurement of GFR is essential for correct dosing. Isotopic methods remain the gold standard for the determination of GFR. Formulae to estimate GFR have improved the assessment of renal function in non-oncological settings. We assessed the utility of these formulae for carboplatin dosing.<p></p> <b>Methods:</b> We studied consecutive subjects receiving adjuvant carboplatin for stage 1 seminoma at our institution between 2007 and 2012. Subjects underwent 51Cr-ethylene diamine tetra-acetic acid (EDTA) measurement of GFR with carboplatin dose calculated using the Calvert formula. Theoretical carboplatin doses were calculated from estimated GFR using Chronic Kidney Disease-Epidemiology (CKD-EPI), Management of Diet in Renal Disease (MDRD) and Cockcroft–Gault (CG) formulae with additional correction for actual body surface area (BSA). Carboplatin doses calculated by formulae were compared with dose calculated by isotopic GFR; a difference <10% was considered acceptable.<p></p> <b>Results:</b> 115 patients were identified. Mean isotopic GFR was 96.9 ml/min/1.73 m2. CG and CKD-EPI tended to overestimate GFR whereas MDRD tended to underestimate GFR. The CKD-EPI formula had greatest accuracy. The CKD-EPI formula, corrected for actual BSA, performed best; 45.9% of patients received within 10% of correct carboplatin dose. Patients predicted as underdosed (13.5%) by CKD-EPI were more likely to be obese (p = 0.013); there were no predictors of the 40.5% receiving an excess dose.<p></p> <b>Conclusions:</b> Our data support further evaluation of the CKD-EPI formula in this patient population but clinically significant variances in carboplatin dosing occur using non-isotopic methods of GFR estimation. Isotopic determination of GFR should remain the recommended standard for carboplatin dosing when accuracy is essential.<p></p&gt
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