425 research outputs found
Social Jetlag and Excessive Daytime Sleepiness from a Sample of Russian Children and Adolescents
PURPOSE: Insufficient nocturnal sleep is a primary source of excessive daytime sleepiness. Most previous research has focused on the disparity between sleep demands and study start times in adolescents. Fewer studies have focused on elementary schoolchildren. We hypothesize that late sleep timing is connected to excessive daytime sleepiness in a sample of Russian children and adolescents. The major goals of our study were to evaluate excessive daytime sleepiness in Russian schoolchildren and adolescents using the Russian version of the Pediatric Daytime Sleepiness Scale (PDSS) and to estimate its relationship with sleep-wake parameters using the Munich Chronotype Questionnaire (MCTQ).
MATERIALS AND METHODS: Student subjects were from public educational facilities in the Republic of Karelia. They completed both the PDSS and the Munich Chronotype Questionnaire to estimate sleep parameters and chronotype (MSFsc). Five hundred and eleven students provided data for the PDSS and sleep-wake variables, and 479 for the full MCTQ data.
RESULTS: The overall prevalence of Excessive Daytime Sleepiness (EDS) in our sample was 18%. The total PDSS score was inversely correlated with sleep length on school nights and was independent of respondents\u27 sex. Higher PDSS scores were associated with later bedtimes on school days and free days, and shorter sleep duration on school days. Late chronotype and more pronounced social jetlag were both positively correlated with high PDSS scores. A negative correlation was found between chronotype and the duration of the sleep period on weekdays (p \u3c 0.001) and a positive correlation was found on weekends (p \u3c 0.001). Longer average sleep duration was positively related to less daytime sleepiness.
CONCLUSION: This study suggests that excessive daytime sleepiness is chronotype-dependent. School start times could be shifted to a later hour to prolong sleep and reduce EDS
Motivation of personnel in an innovative business climate
With increasing understanding of the importance of labor motivation in the personnel management system it is necessary to study the examples of practical implementation of personnel motivation programs that have been tested in successful companies. This work is designed to give answers to the following questions: How and what should motivate employees under the conditions of innovative business development? How is it done in Russia and around the world? What motivating programs are offered by employers today, what are their common features and fundamental differences? The main goal is to identify the best practices of motivation by using the examples of the leading foreign and Russian companies. The main conclusion – even considering the Russian specifics, one large salary is not enough in innovative conditions, therefore progressive companies introduce multifactorial motivation systems, including material and non-material components. The work is of practical value for the Russian business. The continuation of this original research can develop in two directions: "in breadth" and "in depth". In the first case a similar analysis carried out with a large sample of enterprises will reveal additional dependencies. In the second case an empirical study of the reaction to certain motivators and the ways of their implementation within a separate company is proposed.peer-reviewe
Thermocatalytic conversion of petroleum paraffin in the presence of tungsten carbide powders
Russia occupies the third place in the world in terms of stocks of heavy oil raw materials. The development of deposits of light and medium oils makes it inevitable to involve heavy, as well as residual, petroleum raw materials in processing to meet the growing demand for petroleum products. Increase of the depth of oil processing possible in various ways, one of which is the use of new efficient catalysts, resistant to corrosion, poisoning and coking. Tungsten carbide, meeting these requirements, is a promising starting compound for the production of cracking catalysts for heavy oil feedstocks. The influence of tungsten carbide and its calcination temperature on the composition and yield of oil paraffin cracking products on the resulting catalysts was studied to investigate its catalytic activity, the optimum treatment temperature of tungsten carbide was determined. The high catalytic activity of a WC sample calcined at 420°C is shown. Using the physicochemical methods of investigation, the properties of tungsten carbide samples, as well as the composition and properties of the paraffin cracking products in the presence of the catalysts obtained, were studied
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One-sign order parameter in iron based superconductor
The onset of superconductivity at the transition temperature is marked by the onset of order, which is characterized by an energy gap. Most models of the iron-based superconductors find a sign-changing (s±) order parameter [1–6], with the physical implication that pairing is driven by spin fluctuations. Recent work, however, has indicated that LiFeAs has a simple isotropic order parameter [7–9] and spin fluctuations are not necessary [7,10], contrary to the models [1–6]. The strength of the spin fluctuations has been controversial [11,12], meaning that the mechanism of superconductivity cannot as yet be determined. We report the momentum dependence of the superconducting energy gap, where we find an anisotropy that rules out coupling through spin fluctuations and the sign change. The results instead suggest that orbital fluctuations assisted by phonons [13,14] are the best explanation for superconductivity
High-Yield Production and Transfer of Graphene Flakes Obtained by Anodic Bonding
We report large-yield production of graphene flakes on glass by anodic
bonding. Under optimum conditions, we counted several tens of flakes with
lateral size around 20-30 {\mu}m and few tens of flakes with larger size.
60-70% of the flakes have negligible D peak. We show that it is possible to
easily transfer the flakes by wedging technique. The transfer on silicon does
not damage graphene and lowers the doping. The charge mobility of the
transferred flakes on silicon is of the order of 6000 cm^2/V s (at carrier
concentration of 10^12 cm^-2), which is typical for devices prepared on this
substrate with exfoliated graphene.Comment: 17 pages, 6 figures; ACS Nano 201
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