A new method for the measurement and analysis of biomechanical energy delivered by kicking

An accurate measurement of force and biomechanical energy that people can impart through kicking is useful for kick-related sports training. Existing methods are indirect measurements or focus on force and not on the total energy of the kick. A kick test rig was designed, constructed and instrumented to measure the force and displacement of a vertical target subjected to kicking. The kick energy was calculated from the recorded force and displacement histories. The methodology for measurement of kick force and energy was validated by an open stance front kick test by 52 volunteers. The results showed that 67% of the participants could achieve an average energy above 100 J. An increasing trend of kick energy with increasing body weight of participant was observed. The participant’s gender had a strong influence on the kick energy, while training in martial arts does not appear to be a significant parameter. A probability analysis showed that one in one hundred adults will be able to kick with energies exceeding 215 J.     

Addressing quality challenges in the private university sector in Bangladesh: from policy formulation to institutional implementation

Private higher education is growing, especially in developing and transitioning countries. Rapid growth frequently comes with concerns about quality. This article explores challenges and opportunities for higher education quality among private universities in Bangladesh. By presenting a vertical case study that explores interactions among actors at the institutional, national and global spheres, the authors argue for the need of developing quality standards that respond to the local realities of developing and transitioning countries. It is also argued that self-regulation among private universities is likely the most effective pathway for improvement. Bangladesh presents an ideal case for analysis given the rapid growth that higher education has experienced in the last 20 years in that country and given the current policy junction as Bangladesh begins to implement a newly developed quality assurance system. Other countries in the region in early stages of developing quality assurance and accountability systems may benefit from the findings of this study.     

Impact of a computer-based intervention in Chilean children at risk of manifesting reading difficulties / Impacto de una intervención basada en ordenador en niños chilenos con riesgo de manifestar dificultades lectoras

Reading difficulties have reached a prevalence of 3–10% in school-age children. Those who present these difficulties avoid reading and benefit very little from school-based learning opportunities, resulting in maladjustments, dropping out of school and having to repeat grades. Presented here are the results of an intervention based on a computer game intended for explicit phonic training in first-grade school children at risk of possessing reading difficulties. Fifty-six children from a low socioeconomic status (SES) and 31 children from a high socioeconomic status, divided into two groups (control and experimental), participated in the study. After the intervention, participants from the low-SES experimental group had enhanced their skills regarding letter sound recognition, whereas the high-SES experimental group had improved their naming speed. The results are discussed in light of the impact of interventions based on computer games and of the importance of the development of sublexical skills in children at risk of manifesting reading difficulties in transparent orthographies.     

Planning for the Internationalization of a Postgraduate Professional Degree Programme in Library and Information Science

The School of Library and Information Science of the University of South Florida, that has been a pioneer in distance education, has decided to internationalize its offerings with Ibero-America in mind. This article describes some of the steps the School has taken in order to prepare itself for the challenges, particularly cultural and linguistic ones, posed by international students. Given that the level of performance of both traditional and distance students seems to be about identical, the School of Library and Information Service is looking forward to a successful and culturally enriching experience.     

Chemistry at the Nanoscale

Traditionally the kinetics of a chemical reaction has been studied as a set of coupled ordinary differential equations. The law of mass action, a tried and tested principle for reactions involving macroscopic quantities of reactants, gives rise to deterministic equations in which the variables are species concentrations. In recent years, though, as smaller and smaller systems – such as an individual biological cell, say – can be studied quantitatively, the importance of molecular discreteness in chemical reactions has increasingly been realized. This is particularly true when the system is far from the ‘thermodynamic limit’ when the numbers of all reacting molecular species involved are several orders of magnitude smaller than Avogadro’s number. In such situations, each reaction has to be treated as a probabilistic ‘event’ that occurs by chance when the appropriate reactants collide. Explicitly accounting for such processes has led to the development of sophisticated statistical methods for simulation of chemical reactions, particularly those occurring at the cellular and sub-cellular level. In this article, we describe this approach, the so-called stochastic simulation algorithm, and discuss applications to study the dynamics of model regulatory networks.     

The twin prime problem and generalizations (après Yitang Zhang)

We give a short introduction to the recent breakthrough theorem of Yitang Zhang that there are infinitely many pairs of distinct primes (p, q) with |p ? q| < 70 million.     

Sincretismo y pensamiento categorial: génesis y diferencias socioculturales

Resumen

El estudio de la representación del mundo en el niño es una de las vías que permiten acercarse a la génesis del pensamiento infantil, a su progresiva estructuración. Interesados en la evolución del sincretismo y del pensamiento categorial, los diálogos con los niños en torno a las ultra-cosas nos han permitido detectar distintos niveles evolutivos dentro del pensamiento sincrétn o y del categorial y nos han puesto en la pista de posibles diferencias socioculturales ligadas con la pertenencia al medio rural o urbano.     

Professional guilds, tension and knowledge management

Scientific research is a crucial success factor for knowledge intensive firms and is often a joint effort of scientists and managers. However, scientists and managers belong to different “professional guilds,” subscribing to different belief systems and valuing different types of incentives. These differences give rise to tension between scientists and managers. We integrate a large body of literature from knowledge management to develop a new theoretical model predicting that this organizational tension is affected by environmental factors such as the degree of industry munificence, firm-specific factors like knowledge-management policies, and the individual roles of boundary spanners within the firm. Further, we argue that this tension can lead to positive or negative outcomes.     

Proofs produced by secondary school students learning geometry in a dynamic computer environment

As a key objective, secondary school mathematics teachers seek to improve the proof skills of students. In this paper we present an analytic framework to describe and analyze students' answers to proof problems. We employ this framework to investigate ways in which dynamic geometry software can be used to improve students' understanding of the nature of mathematical proof and to improve their proof skills. We present the results of two case studies where secondary school students worked with Cabri-Géeomèetre to solve geometry problems structured in a teaching unit. The teaching unit had theaims of: i) Teaching geometric concepts and properties, and ii) helping students to improve their conception of the nature of mathematical proof and to improve their proof skills. By applying the framework defined here, we analyze students' answers to proof problems, observe the types of justifications produced, and verify the usefulness of learning in dynamicgeometry computer environments to improve students' proof skills.