Differences in the magnitude and reliability of velocity variables collected during 3 variants of the bench press exercise

ABSTRACT

This study aimed to compare the reliability and magnitude of velocity variables between 3 variants of the bench press (BP) exercise in participants with and without BP training experience. Thirty males, 15 with and 15 without BP experience, randomly performed 3 variants of the BP on separate sessions: (I) concentric-only, (II) fast-eccentric and (III) controlled-eccentric. The mean velocity (MV) and maximum velocity (V_max) of the concentric phase were collected against 3 loads (≈30%1RM, 50%1RM, and 75%1RM) with a linear velocity transducer. Reliability was high regardless of the variable, BP variant, and load (coefficient of variation [CV] ≤ 4.47%, intraclass correlation coefficient [ICC] ≥ 0.87). The comparison of the CVs suggested a higher reliability for the fast-eccentric BP (8 out of 12 comparisons), followed by the concentric-only BP (5 out of 12 comparisons), and finally the controlled-eccentric BP (never provided a higher reliability). No differences in reliability were observed between experienced (CV ≤ 4.71%; ICC ≥ 0.79) and non-experienced (CV ≤ 6.29%; ICC ≥ 0.76) participants. The fast-eccentric BP provided the highest MV (p < 0.05) and no differences were observed for V_max. These results support the assessment of movement velocity during the fast-eccentric BP even in participants without experience.     

Web and social media usage by museums: Online value creation

This paper contributes to the understanding of online strategies in the context of museums as examples of cultural organisations, an underrepresented sector in the information management literature. It presents a theoretical framework for understanding the online strategies of museums’ use of Web and social media, their sources of online value (efficiency, novelty, lock-in, complementarities) and some measurements of Internet performance, such as the Alexa Internet ranking and the number of followers of museums in social media. This type of analysis has not been conducted before and the findings will help museum curators and managers of other cultural institutions to appreciate the impact of these technologies and to make better informed decisions regarding online strategies and resource allocation. In addition, the results of this research are applicable to similar organisations, such as archives and cultural exhibitions, as well as to other service organisations related to information, education and entertainment activities.     

Participatory technology development in Cameroon: The route and milestone in the process of its institutionalisation

Summary

The four-year Phase II of the action-research programme "Indigenous Soil and Water Conservation in Africa (ISWC II) started in December 1996 and operates in the French-speaking countries Tunisia, Burkina Faso and Cameroon and in the English-speaking countries Ethiopia, Uganda, Tanzania, and Zimbabwe. It had received a budget-neutral extension from the funders (Netherlands Development Aid, DGIS) for the entire 2001.

This paper is based on the Participatory Technology Development (PTD) experiences with the ISWC II project in Cameroon. The ISWC II project aimed to improve the effectiveness of both indigenous and modern Soil and Water Conservation (SWC) practices through a process of joint experimentation involving farmers, scientists and development agents.

The authors have developed the informal and formal strategies used and their impacts in the process of the institutionalisation of the PTD approach in Cameroon.     

Inter-individual differences in stride frequencies during running obtained from wearable data

ABSTRACT

The purpose of the present study was to identify factors that underlie differences among runners in stride frequency (SF) as a function of running speed. Participants (N = 256; 85.5% males and 14.5% females; 44.1 ± 9.8 years; 181.4 ± 8.4 cm; 75.3 ± 10.6 kg; mean ± SD) shared their wearable data (?Garmin Inc). Individual datasets were filtered to obtain representative relationships between stride frequency (SF) and speed per individual, representing in total 16.128 h of data. The group relationship between SF (72.82 to 94.73 strides · min^?1) and running speed (V) (from 1.64 to 4.68 m · s^?1) was best described with SF = 75.01 + 3.006 V. A generalised linear model with random effects was used to determine variables associated with SF. Variables and their interaction with speed were entered in a stepwise forward procedure. SF was negatively associated with leg length and body mass and an interaction of speed and age indicated that older runners use higher SF at higher speed. Furthermore, run frequency and run duration were positively related to SF. No associations were found with injury incidence, athlete experience or performance. Leg length, body mass, age, run frequency and duration were associated with SFs at given speeds.

KEY POINTS

• On a group level, stride frequency can be described as a linear function of speed: SF (strides · min^?1) = 75.01+ 3.006·speed (m · s^?1) within the range of 1.64 to 4.68 m · s^?1.

• On an individual level, the SF-speed relation is best described with a second order polynomial.

• Leg length and body mass were positively related to stride frequency while age was negatively related to stride frequency.

• Run frequency and run duration were positively related to stride frequency, while running experience, performance and injury incidence were unrelated.

     

The Dialectic Relationship between Research and Practice in Mathematics Teacher Education

This paper addresses issues linking research in student teacher learning with reflection on practice in mathematics teacher education. From a situated perspective on learning and practice, we explore our own practice as teacher educators while researching student teacher learning in our classrooms. We describe a study on student teacher learning, considering student teacher learning as a “process of becoming”, and how the results of this research have affected our development as mathematics teacher educators and members of a community of inquiry. Our work shows how in the mathematics teacher education context the relationship between theory and practice becomes an element of both teacher educator and researcher development.     

Experiences in education innovation: developing tools in support of active learning

The paper focuses on educational projects developed in the ETSII (Escuela Técnica Superior de Ingenieros Industriales) of the Polytechnic University of Madrid during the past few years. These projects were developed as new tools for enhancing the active role of students, for improving practical teaching, especially by means of virtual laboratories and different sets of problems and exercises, and for promoting self-learning. The paper analyses the use of ICT in teaching, with the case of a developed e-learning platform as a tracking system for subjects. The paper concludes by discussing the new educational trends in the Centre, devoted to develop an active role of students by activities such as peer mentoring and laboratory monitors programs, and competitions for achieving multidisciplinary engineering challenges.     

Relevant Changes in Scientific Publishing in Mathematics and Physics

Scientific publishing in mathematics and physics (as in other exact sciences) is rapidly changing, and it is important to identify and predict relevant changes and their potential consequences. To understand such changes, the authors begin with a brief history of scientific publishing and the rise of digital publishing. The study presents a qualitative comparison of the basic features of traditional and digital forms of publications (books, journals, libraries and databases, archives, webinars, forums, digital learning materials), on the basis of which relevant changes (specific for mathematics and physics) are identified and predicted. Several tables describing the most popular and useful scientific online tools for scientists, professors, students, and engineers are listed.