Aging of the (2+1)-dimensional Kardar-Parisi-Zhang model

Extended dynamical simulations have been performed on a 2+1 dimensional driven dimer lattice gas model to estimate ageing properties. The auto-correlation and the auto-response functions are determined and the corresponding scaling exponents are tabulated. Since this model can be mapped onto the 2+1 dimensional Kardar-Parisi-Zhang surface growth model, our results contribute to the understanding of the universality class of that basic system.Comment: 6 pages, 5 figs, 1 table, accepted version in PR

Current without bias and diode effect in shuttling transport of nanoshafts

A row of parallely ordered and coupled molecular nanoshafts is shown to develop a shuttling transport of charges at finite temperature. The appearance of a cu rrent without applying an external bias voltage is reported as well as a natura l diode effect allowing unidirectional charge transport along one field directi on while blocking the opposite direction. The zero-bias voltage current appears above a threshold of initial thermal and/or dislocation energy

Validation of a sports nutrition knowledge questionnaire for athletes in the United Kingdom and Ireland.

Sound general and sports nutrition knowledge in athletes is essential for making appropriate dietary choices. Assessment of nutrition knowledge enables evaluation and tailoring of nutrition education. However, few well-validated tools are available to assess nutrition knowledge in athletes. The objective of the present study was to establish the validity of the Platform to Evaluate Athlete Knowledge Sports - Nutrition Questionnaire (PEAKS-NQ) for use in the United Kingdom and Irish (UK-I) athletes. To confirm content validity, twenty-three sports nutritionists (SNs) from elite, UK-I sports institutes provided feedback on the PEAKS-NQ via a modified Delphi method. After minor changes, the UK-I version of the PEAKS-NQ was administered to UK-I SN from the British Dietetic Association Sport and Exercise Nutrition Register, and elite athletes (EA) training at elite sports institutes in the UK and Ireland. Independent samples -test and independent samples median tests were used to compare PEAKS-NQ total and subsection scores between EA and SN (to assess construct validity). Cronbach's alpha (good ≥ 0⋅7) was used to establish internal consistency. The SN achieved greater overall [SN ( 23) 92⋅3 (9⋅3) EA ( 154): 71⋅4 (10⋅0)%; < 0⋅001] and individual section scores ( < 0⋅001) except Section B, Identification of Food Groups ( = 0⋅07). Largest knowledge differences between SN and EA were in Section D, Applied Sports Nutrition [SN: 88⋅5 (8⋅9) EA: 56⋅7 (14⋅5)%; < 0⋅00]. Overall ES was large (2⋅1), with subsections ranging from 0⋅6 to 2⋅3. Cronbach's alpha was good (0⋅83). The PEAKS-NQ had good content and construct validity, supporting its use to assess nutrition knowledge of UK-I athletes

Plausible self-reported dietary intakes in a residential facility are not necessarily reliable

Background/Objectives: Comparing reported energy intakes with estimated energy requirements as multiples of basal metabolic rate (Ein:BMR) is an established method of identifying implausible food intake records. The present study aimed to examine the validity of self-reported food intakes believed to be plausible. Subjects/Methods: One hundred and eighty men and women were provided with all food and beverages for two consecutive days in a residential laboratory setting. Subjects self-reported their food and beverage intakes using the weighed food diary method (WDR). Investigators covertly measured subjects’ actual consumption over the same period. Subjects also reported intakes over four consecutive days at home. BMR was measured by indirect calorimetry. Results: Average reported energy intakes were significantly lower than actual intakes (11.2 and 11.8 MJ/d, respectively, P<0.001). Two-thirds (121) of the WDR were under-reported to varying degrees. Only five of these were considered as implausible using an Ein:BMR cut-off value of 1.03*BMR. Under-reporting of food and beverage intakes, as measured by the difference between reported and actual intake, was evident at all levels of Ein;BMR. Reported energy intakes were lower still (10.2 MJ/d) while subjects were at home. Conclusions: Under-recording of self-reported food intake records was extensive but very few under-reported food intake records were identified as implausible using energy intake to BMR ratios. Under-recording was evident at all levels of energy intake

Developing a Method to Test the Validity of 24 Hour Time Use Diaries Using Wearable Cameras: A Feasibility Pilot

Self-report time use diaries collect a continuous sequenced record of daily activities but the validity of the data they produce is uncertain. This study tests the feasibility of using wearable cameras to generate, through image prompted interview, reconstructed 'near-objective' data to assess their validity. 16 volunteers completed the Harmonised European Time Use Survey (HETUS) diary and used an Autographer wearable camera (recording images at approximately 15 second intervals) for the waking hours of the same 24-hour period. Participants then completed an interview in which visual images were used as prompts to reconstruct a record of activities for comparison with the diary record. 14 participants complied with the full collection protocol. We compared time use and number of discrete activities from the diary and camera records (using 10 classifications of activity). In terms of aggregate totals of daily time use we found no significant difference between the diary and camera data. In terms of number of discrete activities, participants reported a mean of 19.2 activities per day in the diaries, while image prompted interviews revealed 41.1 activities per day. The visualisations of the individual activity sequences reveal some potentially important differences between the two record types, which will be explored at the next project stage. This study demonstrates the feasibility of using wearable cameras to reconstruct time use through image prompted interview in order to test the concurrent validity of 24-hour activity time-use budgets. In future we need a suitably powered study to assess the validity and reliability of 24-hour time use diaries