Assessing the optimal time interval between growth measurements using a combined data set of weights and heights from 5948 infants

BackgroundCurrent guidance on the optimum interval between measurements in infancy is not evidence based. We used routine data to explore how measurement error and short-term variation (‘noise’) might affect interpretation of infant weight and length gain (‘signal’) over different time intervals.MethodUsing a database of weights and lengths from 5948 infants aged 0–12 months, all pairs of measurements per child 2, 4 and 8 weeks apart were extracted. Separately, 20 babies aged 2–10 months were weighed on six occasions over 3 days to estimate the SD of the weight difference between adjacent measurements (=116 g). Values of 116 g and 0.5 cm for ‘noise’ were then used to model its impact on (a) the estimated velocity centile and (b) the chance of seeing no growth during the interval, in individuals.ResultsThe average gain in weight and length was much larger than the corresponding SD over 8-week and 4-week time intervals, but not over 2 weeks. Noise tended to make apparent velocity less extreme; after age 6 months, a 2-week velocity that appeared to be on to the ninth centile, would truly be on the second–third centile if measured with no noise. For 2-week intervals, there was a 16% risk of no apparent growth by age 10 months.ConclusionsGrowth in infancy is so rapid that the change in measurements 4–8 weeks apart is unlikely ever to be obscured by noise, but after age 6 months, measurements 2 weeks or less apart should be treated with caution when assessing growth faltering.

Stiffness and Distance of Lateral Support Member Considering Buckling Strength of Sliding Track Panel

Recently, the concept of a Sliding Track Panel (STP) system, which allows the bridge to slide in the longitudinal direction, has been proposed for continuous welded rail method laid on long span non-ballast bridges, such as truss railway bridges. The performance of the STP system is determined based on the ability to prevent the lateral buckling of STP. This study attempts to derive the optimum interval distance and required stiffness of the lateral support member to be installed in the STP system through buckling analysis. According to the analysis, the interval distance of lateral support member, which satisfies the strength of STP, is less than 2.8 m and the rigidity is more than 800 N/mm.

More work, better health? The moderation effect of employee-organizational psychological distance

Based on the data obtained from 1014 Chinese employees, this study clarified the relationship between work hours, psychological distance, and the occupational mental health of employees. This study revealed a curvilinear and almost inverted U-shaped relationship between work hours and occupational mental health. Furthermore, the results showed that the optimum interval of work hours to maintain high-quality occupational mental health was indicated as “typical overtime work,” and the employee-organizational psychological distance may positively moderate this inverted U-shaped relationship, and a “close” employee-organizational psychological distance may alleviate the pressure of work hours and help to maintain high-quality occupational mental health.

Internet Research Agency Twitter activity predicted 2016 U.S. election polls

In 2016, the Internet Research Agency (IRA) deployed thousands of Twitter bots that released hundreds of thousands of English language tweets. It has been hypothesized this affected public opinion during the 2016 U.S. presidential election. Here we test that hypothesis using vector autoregression (VAR) comparing time series of election opinion polling during 2016 versus numbers of re-tweets or ‘likes’ of IRA tweets. We find that changes in opinion poll numbers for one of the candidates were consistently preceded by corresponding changes in IRA re-tweet volume, at an optimum interval of one week before. In contrast, the opinion poll numbers did not correlate with future re-tweets or ‘likes’ of the IRA tweets. We find that the release of these tweets parallel significant political events of 2016 and that approximately every 25,000 additional IRA re-tweets predicted a one percent increase in election opinion polls for one candidate. As these tweets were part of a larger, multimedia campaign, it is plausible that the IRA was successful in influencing U.S. public opinion in 2016.

Влияние режима отжига на свойства терагерцевой фотопроводящей антенны на основе LT-GaAs

Low-temperature gallium arsenide (LT-GaAs) films were grown by the method of molecularbeam epitaxy (MBE) at a reduced temperature (230°C) on GaAs(100) substrates and subjected to postgrowth annealing in various regimes. Photoconductive antennas (PCAs) with flag geometry formed on the film surface were characterized by terahertz (THz) response power at various bias voltages. The method of THz spectroscopy was used to study the characteristics of PCAs based on LT-GaAs films annealed in various regimes and the optimum interval of postgrowth annealing temperatures (670–720°C) was established.