难题与破解:新疆少数民族传统体育发展中的文化困境和对策

以新时代党和国家领导人关于民族工作的重要论述以及《新疆的文化保护与发展》《新疆的若干历史问题》白皮书为指导，研究认为，对中华母体体育文化的认识有待提高、文化属性的缺位相对明显、不良宗教文化的附着存在较大可能以及游牧文化的离散成为常态，是新疆少数民族传统体育发展过程中面临的特殊性文化困境。上述文化困境产生的主要原因在于：在新疆少数民族传统体育发展中，存在着机械性"华夷之辩"观念的浸入、对文化属性认知的不足、文化差异的过度强调、现代化进程中的文化迷失等四方面问题。破解新疆少数民族传统体育发展中的文化困境，需要从转变思想观念，给予新疆少数民族传统体育准确定位；加强多方引导，深化对新疆少数民族传统体育文化属性的认识；树立明确观念，客观认识新疆少数民族传统体育中的文化差异；推进体育文旅，促进新疆少数民族传统体育文化和产业的融合发展等四方面展开。     

Mechanical determinants of acceleration and maximal sprinting speed in highly trained young soccer players

Abstract

The aim of the present study was to examine, in highly trained young soccer players, the mechanical horizontal determinants of acceleration (Acc) and maximal sprinting speed (MSS). Eighty-six players (14.1 ± 2.4 year) performed a 40-m sprint to assess Acc and MSS. Speed was measured with a 100-Hz radar, and theoretical maximal velocity (V₀), horizontal force (F₀) and horizontal power (P_max) were calculated. Within each age group, players were classified as high Acc/fast MSS (>2% faster than group mean), medium (between ?2% and +2%), and low/slow (>2% slower). Acc and MSS were very largely correlated (?0.79; 90% confidence limit [?0.85; ?0.71]). The determinants (multiple regression r² = 0.84 [0.78; 0.89]) of Acc were V₀ (partial r: 0.80 [0.72; 0.86]) and F₀ (0.57 [0.44; 0.68]); those of MSS (r² = 0.96 [0.94; 0.97]) were V₀ (0.96 [0.94; 0.97]) and P_max (0.73 [0.63; ?0.80]). High/Med have likely greater F₀ (Cohen’s d: +0.8 [0.0; 1.5]), V₀ (+0.6 [?0.1; 1.3]) and P_max (+0.9 [0.2; 1.7]) than Low/Med. High/Fast have an almost certainly faster V₀ (+2.1 [1.5; 2.7]) and a likely greater P_max (+0.6 [?0.1; 1.3]) than High/Med, with no clear differences in F₀ (?0.0 [?0.7; 0.6]). Speed may be a generic quality, but the mechanical horizontal determinants of Acc and MSS differ. While maximal speed training may improve both Acc and MSS, improving horizontal force production capability may be efficient to enhance sprinting performance over short distances.     

Asynchronous switching for switched nonlinear input delay systems with unstable subsystems

We study the input-to-state stability (ISS) of switched nonlinear input delay systems under asynchronous switching. Our results apply to cases where some subsystems of the switched systems are not necessarily stable under the influence of input delay. By making a compromise among the matched-stable period, the matched-unstable period, and the unmatched period and allowing the increase of the Lyapunov–Krasovskii functional (LKF) on all the switching times, the extended stability criteria for switched delay systems in generally nonlinear setting are derived first. Then, we focus on switched nonlinear input delay systems where the presence of the input delay leads to the instability of some subsystems of it. By explicitly constructing input-to-state stable LKF, the sufficient conditions for ISS of switched nonlinear input delay systems under asynchronous switching are presented. Finally, two examples are given to illustrate the effectiveness of the proposed theory.     

Socioeconomic Implications of Telecommunications Liberalization: India in the International Context

Telecommunications restructuring have evolved differently in Asia and Latin America. While Asian governments have moved cautiously in bringing changes to the sector, Latin American nations have implemented radical ownership and market transformations. The Indian telecommunications reform falls in between these two general regional trends. The choice of a high component of competition, increased private participation, and no privatization of the national carrier set conditions that will trigger unique socioeconomic effects. This article identifies and highlights the likely implications of the Indian reform on key economic and social issues, such as the cost of services, cross-subsidies, network interconnection, private investments, universal services, employment, and the possible rise of an information-intensive economy. It does so by comparing and contrasting the Indian experience with dominant reform strategies elsewhere in the developing world.     

铝电解故障诊断的研究现状及发展趋势

铝电解是一个非线性、多耦合、时变和大时滞过程,受强电场、强磁场、强热场交互干扰,故障发生频繁。本文综述了国内外铝电解故障诊断研究状况,阐述了目前铝电解故障诊断的主要方法和发展趋势,为铝电解故障诊断技术的实用化提供理论依据。     

Haptoglobin Polymorphism and Association with Complications in Ghanaian Type 2 Diabetic Patients

There is scanty information on the role of genetic factors, especially those relating to haptoglobin (Hp) phenotypes in the expression of complications among diabetes mellitus patients in Ghana. In this study, we investigated whether there is any association between Hp phenotypes and diabetic complications and to determine if association of the Hp phenotypes with diabetic complications in Ghanaian diabetics differ from those in Caucasians. A total of 398 participants were randomly recruited into the study. These comprised diabetic patients numbering 290 attending a diabetes Clinic in Ghana and 108 non-diabetic controls from the same community. Analyses of the results indicate that most of the diabetics with complications were of the Hp 2–2 (35%) and Hp 2–1 (23.9%) phenotypes. Fewer diabetics were found to be of the Hp 2–1 M phenotype. The controls were mostly of Hp 1–1 and Hp 2–1 M phenotypes. The odds ratio of having complications in a diabetic with an Hp 2–2 phenotype was 18.27 times greater than that for Hp 0–0. Hp 2–2 phenotype with its poor antioxidant activity may therefore be a useful predictor for the propensity of an individual to develop diabetes complications.     

Responsibility and School Choice in Education

Consider the following argument for school choice, based on an appeal to the virtues of the market: allowing parents some measure of choice over their particular children's education ultimately serves the interests of all children, because creating a market mechanism in state education will produce improvements through the same pressures that lead to greater efficiency and quality when markets are deployed in more familiar contexts. The argument fails, because it is committed to a principle of equal concern, which (after analysis) implies that a market in education is acceptable only if it is right to hold children disadvantaged by their parents' poor market choices substantively responsible for the fact. Since that claim is untenable, the market‐based argument for school choice not only fails, but also turns out to rely on principles which in fact condemn the very policy it was supposed to support.     

Using causal models to bridge the divide between big data and educational theory

An extraordinary amount of data is becoming available in educational settings, collected from a wide range of Educational Technology tools and services. This creates opportunities for using methods from Artificial Intelligence and Learning Analytics (LA) to improve learning and the environments in which it occurs. And yet, analytics results produced using these methods often fail to link to theoretical concepts from the learning sciences, making them difficult for educators to trust, interpret and act upon. At the same time, many of our educational theories are difficult to formalise into testable models that link to educational data. New methodologies are required to formalise the bridge between big data and educational theory. This paper demonstrates how causal modelling can help to close this gap. It introduces the apparatus of causal modelling, and shows how it can be applied to well-known problems in LA to yield new insights. We conclude with a consideration of what causal modelling adds to the theory-versus-data debate in education, and extend an invitation to other investigators to join this exciting programme of research.

Practitioner notes

What is already known about this topic

• ‘Correlation does not equal causation’ is a familiar claim in many fields of research but increasingly we see the need for a causal understanding of our educational systems.
• Big data bring many opportunities for analysis in education, but also a risk that results will fail to replicate in new contexts.
• Causal inference is a well-developed approach for extracting causal relationships from data, but is yet to become widely used in the learning sciences.

What this paper adds

• An overview of causal modelling to support educational data scientists interested in adopting this promising approach.
• A demonstration of how constructing causal models forces us to more explicitly specify the claims of educational theories.
• An understanding of how we can link educational datasets to theoretical constructs represented as causal models so formulating empirical tests of the educational theories that they represent.

Implications for practice and/or policy

• Causal models can help us to explicitly specify educational theories in a testable format.
• It is sometimes possible to make causal inferences from educational data if we understand our system well enough to construct a sufficiently explicit theoretical model.
• Learning Analysts should work to specify more causal models and test their predictions, as this would advance our theoretical understanding of many educational systems.