Acute effect of different minimalist shoes on foot strike pattern and kinematics in rearfoot strikers during running

Despite the growing interest in minimalist shoes, no studies have compared the efficacy of different types of minimalist shoe models in reproducing barefoot running patterns and in eliciting biomechanical changes that make them differ from standard cushioned running shoes. The aim of this study was to investigate the acute effects of different footwear models, marketed as “minimalist” by their manufacturer, on running biomechanics. Six running shoes marketed as barefoot/minimalist models, a standard cushioned shoe and the barefoot condition were tested. Foot–/shoe–ground pressure and three-dimensional lower limb kinematics were measured in experienced rearfoot strike runners while they were running at 3.33 m · s^?1 on an instrumented treadmill. Physical and mechanical characteristics of shoes (mass, heel and forefoot sole thickness, shock absorption and flexibility) were measured with laboratory tests. There were significant changes in foot strike pattern (described by the strike index and foot contact angle) and spatio-temporal stride characteristics, whereas only some among the other selected kinematic parameters (i.e. knee angles and hip vertical displacement) changed accordingly. Different types of minimalist footwear models induced different changes. It appears that minimalist footwear with lower heel heights and minimal shock absorption is more effective in replicating barefoot running.     

An empirical analysis of the performance of Vietnamese higher education institutions

This article provides an analysis of the academic performance of higher education institutions (HEIs) in Vietnam with 50 universities and 50 colleges in 2011/12. The two-stage semiparametric data envelopment analysis is used to estimate the efficiency of HEIs and investigate the effects of various factors on their performance. The findings reveal that HEIs in the surveyed sample show that there are still potential avenues to improve their existing performance. There appears to be a difference in the efficiencies of public and private HEIs in the reported year. It is noted that the inefficiency of HEIs are not entirely a result of managerial performance, but also influenced by other factors such as location, age and the contribution of tuition fees. Our results are expected to provide more understanding of the operational efficiency of HEIs for educational managers and policymakers to find possible solutions to improve the performance of Vietnamese higher education.     

The nature of cancer

The prevention and cure of cancer has been one of the great goals of medical science for many years. Although only partial success can yet be claimed, intensive research on an international basis has led to a greatly improved understanding of the mechanism of its causation. This masterly review of the current state of knowledge, by one of the most eminent research workers in this field, concludes on an optimistic note: there are sound grounds for supposing that cancerous cells can potentially be restored to their normal state and there are clues to ways of finding the kinds of substance which might effect this.     

Effects of mild running on substantia nigra during early neurodegeneration

Moderate physical exercise acts at molecular and behavioural levels, such as interfering in neuroplasticity, cell death, neurogenesis, cognition and motor functions. Therefore, the aim of this study is to analyse the cellular effects of moderate treadmill running upon substantia nigra during early neurodegeneration. Aged male Lewis rats (9-month-old) were exposed to rotenone 1mg/kg/day (8 weeks) and 6 weeks of moderate treadmill running, beginning 4 weeks after rotenone exposure. Substantia nigra was extracted and submitted to proteasome and antioxidant enzymes activities, hydrogen peroxide levels and Western blot to evaluate tyrosine hydroxylase (TH), alpha-synuclein, Tom-20, PINK1, TrkB, SLP1, CRMP-2, Rab-27b, LC3II and Beclin-1 level. It was demonstrated that moderate treadmill running, practiced during early neurodegeneration, prevented the increase of alpha-synuclein and maintained the levels of TH unaltered in substantia nigra of aged rats. Physical exercise also stimulated autophagy and prevented impairment of mitophagy, but decreased proteasome activity in rotenone-exposed aged rats. Physical activity also prevented H₂O₂ increase during early neurodegeneration, although the involved mechanism remains to be elucidated. TrkB levels and its anterograde trafficking seem not to be influenced by moderate treadmill running. In conclusion, moderate physical training could prevent early neurodegeneration in substantia nigra through the improvement of autophagy and mitophagy.     

Effects of resisted sprint training on sprinting ability and change of direction speed in professional soccer players

Resisted sprint training consists of performing overloaded sprints, which may produce greater effects than traditional sprint training. We compared a resisted sprint training with overload control versus an unresisted sprint training program on performance in soccer players. Eighteen elite athletes were randomly assigned to resisted (RST) or unresisted sprint training protocol (UR). Before and after a 6-week training period, sprinting ability, change of direction speed (COD), vertical jumps (SJ and CMJ), mean power (MP) and mean propulsive power (MPP) at distinct loads were assessed. Both groups improved sprinting ability at all distances evaluated (5m: UR = 8%, RST = 7%; 10m: UR = 5%, RST = 5%; 15m: UR = 4%, RST = 4%; 20m: UR = 3%, RST = 3%; 25m: UR = 2%, RST = 3%;), COD (UR = 6%; RST = 6%), SJ (UR = 15%; RST = 13%) and CMJ (UR = 15%; RST = 15%). Additionally, both groups increased MP and MPP at all loads evaluated. The between-group magnitude-based inference analysis demonstrated comparable improvement (“trivial” effect) in all variables tested. Finally, our findings support the effectiveness of a short-term training program involving squat jump exercise plus sprinting exercises to improve the performance of soccer players.     

Conceptual navigation in knowledge management environments using NavCon

This article presents conceptual navigation and NavCon, an architecture that implements this navigation in World Wide Web pages. NavCon architecture makes use of ontology as metadata to contextualize user search for information. Based on ontologies, NavCon automatically inserts conceptual links in Web pages. By using these links, the user may navigate in a graph representing ontology concepts and their relationships. By browsing this graph, it is possible to reach documents associated with the user desired ontology concept. This Web navigation supported by ontology concepts we call conceptual navigation. Conceptual navigation is a technique to browse Web sites within a context. The context filters relevant retrieved information. The context also drives user navigation through paths that meet his needs. A company may implement conceptual navigation to improve user search for information in a knowledge management environment. We suggest that the use of an ontology to conduct navigation in an Intranet may help the user to have a better understanding about the knowledge structure of the company.     

Is it natural or processed? Elementary school teachers and conceptions about materials

This paper explores the science content knowledge of elementary school teachers, and its possible role in helping them teach effectively. These issues are explored in the context of an investigation of the views of 106 elementary school teachers who had participated in professional development courses which focused on the topic “natural and processed materials.” These practising teachers revealed a range of conceptions about materials, which have been categorized into broad types. Some of the teachers showed shifts in conceptions, from what could be described as “naïve” conceptions to more scientific views, after a 2‐day professional development activity. © 2000 John Wiley & Sons, Inc. J Res Sci Teach 37: 1154–1170, 2000     

Improving performance aligning business analytics with process orientation

How to align business analytics with process orientation initiatives and how management can influence a synergistic accomplishment of these two elements in order to streamline organizational performance is a foremost managerial issue. By means of a quantitative research effort, a study was designed to investigate the relationships among these constructs. Empirical data were collected in 2011 from a survey of 368 large and mid-sized industrial and service companies headquartered in Brazil. A quantitative analysis was performed, and both the reliability and validity of the scales were evaluated prior to using structural equation modeling. The results demonstrate that the direct effects among BPO, analytical indicators and performance can be taken as statistically significant. The findings also demonstrate that BPO and analytical indicators can be taken as predictors of performance. The paper discusses these results and their managerial implications, as well as some research paths for future studies on the topic.     

Does a 4-week training period with hand paddles affect front-crawl swimming performance?

ABSTRACT

This study investigated the effects of a 4-week training with hand paddles (HPD) on front-crawl swimming performance (SP), clean swimming speed (SPEED), stroke rate (SR), stroke length (SL) and tethered force (TF). Twenty swimmers (10 men and 10 women) were paired according to performance and gender, and were randomly assigned to control (CON, 22.4 ± 2.3 years) or HPD (21.8 ± 1.9 years) groups. During 4 weeks both groups performed the same training, except for a sprint training set (3 times/week, 10 × 10 strokes all-out, 1-min rest) completed with (HPD = 320 cm²) and without (CON) paddles. Afterwards, both groups performed the same training over a 2-week taper period. SP, SPEED, SR, SL and TF were assessed before (PRE) and after the 4-week period (POST), after the first (T1) and second taper weeks (T2). Swimmers rated their perceived exertion for the sprint training set (RPE_TS) and the training session for determining internal training load (ITL). SP, SPEED, SR, SL and TF did not change from PRE to POST, T1 and T2. ITL and RPE_TS were not different between groups. Training 4 weeks with HPD does not affect swimming performance, so the use of HPD remains unsupported in such period.