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21.
We aimed to analyse the handgrip positioning and the wedge effects on the backstroke start performance and technique. Ten swimmers completed randomly eight 15 m backstroke starts (four with hands on highest horizontal and four on vertical handgrip) performed with and without wedge. One surface and one underwater camera recorded kinematic data. Standardised mean difference (SMD) and 95% confidence intervals (CI) were used. Handgrip positioning did not affect kinematics with and without wedge use. Handgrips horizontally positioned and feet over wedge displayed greater knee angular velocity than without it (SMD = ?0.82; 95% CI: ?1.56, ?0.08). Hands vertically positioned and feet over wedge presented greater take-off angle (SMD = ?0.81; 95% CI: ?1.55, ?0.07), centre of mass (CM) vertical positioning at first water contact (SMD = ?0.97; 95% CI: ?1.87, ?0.07) and CM vertical velocity at CM immersion (SMD = 1.03; 95% CI: 0.08, 1.98) when comparing without wedge use. Swimmers extended the hip previous to the knee and ankle joints, except for the variant with hands vertically positioned without wedge (SMD = 0.75; 95% CI: ?0.03, 1.53). Swimmers should preserve biomechanical advantages achieved during flight with variant with hands vertically positioned and wedge throughout entry and underwater phase.  相似文献   
22.
Development of mechanical engineering curricula at the University of Minho   总被引:1,自引:1,他引:0  
The implementation of the Bologna protocol in the European Union has set new goals for the whole higher education system as: (a) a quality assessment for university courses; (b) a framework for the exchange of students and academics; and (c) an opportunity for changing the teaching/learning procedures and methodologies. Within the context, the mechanical engineering curricula at the University of Minho have been comprehensively formulated in order to meet these and future challenges and expectations. The whole process has been based upon various cornerstones: the legal framework for the higher education system; the introduction of new learning methodologies and an accurate survey and understanding of the existing strong and week points of the previous experience. For this purpose, a comprehensive evaluation has been carried out with former students and a detailed map has been formulated regarding their professional careers and experiences. Furthermore, a discussion has been carried out in order to define the mission of the graduate in mechanical engineering. In brief, such mission may be referred by his ability to participate in the wealth creation through technology based innovation. Within this context, the curriculum has been structured in order to meet such goals. In addition to strong foundations in physics and mathematics, new subjects are introduced into the curriculum. The whole education is based upon project development which stimulates the students' initiative, responsibility and their ability to integrate knowledge. Throughout the curriculum, students are enrolled into research projects developed in the department and it is expected that a few selected projects may be taken into a quasi industrial stage.  相似文献   
23.
The aim of this study was to determine whether spatiotemporal interactions between footballers and the ball in 1 vs. 1 sub-phases are influenced by their proximity to the goal area. Twelve participants (age 15.3 ± 0.5 years) performed as attackers and defenders in 1 vs. 1 dyads across three field positions: (a) attacking the goal, (b) in midfield, and (c) advancing away from the goal area. In each position, the dribbler was required to move beyond an immediate defender with the ball towards the opposition goal. Interactions of attacker-defender dyads were filmed with player and ball displacement trajectories digitized using manual tracking software. One-way repeated measures analysis of variance was used to examine differences in mean defender-to-ball distance after this value had stabilized. Maximum attacker-to-ball distance was also compared as a function of proximity-to-goal. Significant differences were observed for defender-to-ball distance between locations (a) and (c) at the moment when the defender-to-ball distance had stabilized (a: 1.69 ± 0.64 m; c: 1.15 ± 0.59 m; P < 0.05). Findings indicate that proximity-to-goal influenced the performance of players, particularly when attacking or advancing away from goal areas, providing implications for training design in football. In this study, the task constraints of football revealed subtly different player interactions than observed in previous studies of dyadic systems in basketball and rugby union.  相似文献   
24.
In microcirculation, red blood cells (RBCs) flowing through bifurcations may deform considerably due to combination of different phenomena that happen at the micro-scale level, such as: attraction effect, high shear, and extensional stress, all of which may influence the rheological properties and flow behavior of blood. Thus, it is important to investigate in detail the behavior of blood flow occurring at both bifurcations and confluences. In the present paper, by using a micro-PTV system, we investigated the variations of velocity profiles of two working fluids flowing through diverging and converging bifurcations, human red blood cells suspended in dextran 40 with about 14% of hematocrit level (14 Hct) and pure water seeded with fluorescent trace particles. All the measurements were performed in the center plane of rectangular microchannels using a constant flow rate of about 3.0 × 10−12 m3/s. Moreover, the experimental data was compared with numerical results obtained for Newtonian incompressible fluid. The behavior of RBCs was asymmetric at the divergent and convergent side of the geometry, whereas the velocities of tracer particles suspended in pure water were symmetric and well described by numerical simulation. The formation of a red cell-depleted zone immediately downstream of the apex of the converging bifurcation was observed and its effect on velocity profiles of RBCs flow has been investigated. Conversely, a cell-depleted region was not formed around the apex of the diverging bifurcation and as a result the adhesion of RBCs to the wall surface was enhanced in this region.  相似文献   
25.
The development of five courses, aimed at advanced engineering training, using the Internet, is described in this paper. A European consortium was responsible for the development, implementation and testing of the courses through the organization of virtual classes on the Internet. An important outcome was the definition of the training service characteristics, which led to the development of a quality system based on four fundamental concepts: credit, accreditation, certification and qualification. Professionals of several age groups and industrial sectors with different expectations as well as engineering students attended pilot virtual classes. From the trainee's side, we report on how the training opportunity was received and how the training service provided was felt. The main project successes and a few weak points and a number of important recommendations are listed for future reference.  相似文献   
26.
We investigated the initial development of reading and spelling in European Portuguese. First-graders, tested in February and June, had to read and spell words and pseudowords. In February there were regularity and graphemic complexity effects, indicating that these children relied on grapheme–phoneme conversion. The lexicality effect found in spelling, in June, suggest that by the end of first grade these children had begun to construct an orthographic lexicon. However, lexical addressing is not inconsistent with phonological mediation as regularization errors increased between the sessions. Additionally, the previously reported similarity in global performance of Portuguese and French beginning readers may conceal processing differences that are related to specific characteristics of the corresponding orthographic codes.
Sandra FernandesEmail:
  相似文献   
27.
Education and Information Technologies - Universities are encouraging the implementation of innovative methodologies and teaching strategies to develop an interactive and appealing educational...  相似文献   
28.
ABSTRACT

Increased school autonomy and a greater focus on achieving school effectiveness and improvement has made it essential to reconsider the role of school leaders (OECD 2009, Creating Effective Teaching and Learning Environments: First Results from TALIS. Paris: OECD Publishing). This recommends that leadership development in this rapidly changing world deserves significant consideration compared to the past. With the increasing interest entrusted to school leadership, this article reports on how school leaders are currently prepared by the higher education programmes offered in two out of three universities in Fiji. Through an extensive literature review as well as through programme documents and policy reviews, this article focuses on current educational leadership post-graduate courses offered at these Fijian universities and highlight areas of strengths as well as suggests recommendations for improvement that are in line with identified needs for effective principal preparation in a Fijian context with key connections made to the larger South Pacific region.  相似文献   
29.
A great deal of televised political advertising is seen every electoral year. Expenditures on this type of political communication have reached the all-time high in the past elections. Clearly, political candidates believe that televised political advertising is an effective way to communicate with voters. This study investigates the effects of repetition of negative political ads on candidate evaluations. A pilot study shows situations in which repetition can both benefit and harm the evaluation of the sponsor of a negative political ad. The main study explores a factor that makes a negative political ad more effective, increasing positive reactions toward the sponsor and negative reactions toward the target of the ad. Implications of these results for society, attitudes, and learning are discussed.  相似文献   
30.
The main purpose of this study was to compare the effect of the constant load and self-paced exercise with similar total work on autonomic control after endurance exercise. Ten physically active men were submitted to (i) a maximal incremental exercise test, (ii) a 4-km cycling time trial (4-km TT), and (iii) a constant workload test with identical total external work performed at 4-km TT. Gas exchange was measured throughout the tests, while blood lactate, heart rate, and heart rate variability (HRV) were measured during the passive recovery. Power output measured at the last lap (i.e. 3600–4000?m) of 4-km TT (316?±?89?W) was statistically higher than power output measured at the end of the constant workload exercise (211?±?42?W). The 4-km TT produced higher values of blood lactate concentration (8.8?±?2.1?mmol?L?1) than the constant workload test (7.8?±?2.1?mmol?L?1). The heart rate recovery measured at 60?s (constant workload: 37?±?7?bpm; 4-km TT: 30?±?6) and 120?s (constant workload: 57?±?9?bpm; 4-km TT: 51?±?9?bpm) were higher in the constant workload than in the self-paced exercise. The HRV (i.e. RMSSD30s) was statistically higher in the constant load exercise measured at 120, 420, 450, 480, 540, and 570?s than the self-paced exercise. These findings suggest that the autonomic control responses were dependent of the endurance exercise modalities, with parasympathetic activity being delayed after self-paced exercise, as evidenced by post-exercise heart rate indices.  相似文献   
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