Bar velocities capable of optimising the muscle power in strength-power exercises

This study aimed at testing whether there are mean propulsive velocities (MPVs) capable of maximising the mean propulsive power (MPP) during the execution of bench press (BP), bench throw (BT), half squat (HS) and jump squat (JS). Additionally, we assessed the differences in MPP/MPV between ballistic and traditional exercises. Seventeen male rugby sevens players performed MPP tests in BP, BT, HS and JS and maximum isometric force (MIF) tests in HS and BP. The JS presented higher MPP (977.4 ± 156.2 W) than the HS (897.9 ± 157.7 W) (P < 0.05); the BP (743.4 ± 100.1 W) presented higher MPP than the BT (697.8 ± 70.4 W) (P < 0.05). Ballistic exercises presented higher optimum MPV (JS = 1.02 ± 0.07 m·s^?1; BT = 1.67 ± 0.15 m·s^?1) than traditional exercises (HS = 0.93 ± 0.08 m·s^?1; BP = 1.40 ± 0.13 m·s^?1) (P < 0.05). The optimum MPP in the JS, BT, HS and BP occurred at 28.2 ± 5.79, 23.3 ± 4.24, 32.4 ± 9.46 and 27.7 ± 5.33% of the MIF, respectively. The coefficient of variation (CV) of MPV at optimum MPP ranged from 7.4% to 9.7%, while the CV of %MIF ranged from 18.2% to 29.2%. The MPV is a more precise indicator of the optimum loads than the percentages of MIF due to its low inter-subject variability as expressed by CV. Therefore, MPV can be used to determine the optimum power load in the four investigated exercises.     

Enhancing consent forms to support participant decision making in multimodal learning data research

Advances in the field of multimodal learning analytics (MMLA) research is often accomplished by actively exploring new technologies and techniques related to the collection and analysis of data. Exploration of ethical principles and procedures for governing the use of new technologies and techniques, however, is not as readily pursued. As collected data grow in complexity and invasiveness, potentially, a growing need is arising to scrutinize ethical aspects of MMLA research. In our study, we introduce an informed consent comprehension test for educational technology research and assess the effects of enhancing MMLA consent forms on comprehension of informed consent and on rates of enrollment in a MMLA study. One form is written from a researcher perspective and the other from a participant perspective. Results of the study involving first-year undergraduate students suggest that the overall level of comprehension did not differ between conditions. Yet, the participant-oriented consent form resulted in significantly lower rates of enrollment. Implications for MMLA researchers are discussed.     

Self-reported and activPALTM-monitored physical activity and sedentary behaviour in college students: Not all sitting behaviours are linked to perceived stress and anxiety

ABSTRACT

This study examined relationships between physical activity (PA) and sedentary behaviour (SB) with state-trait anxiety and stress. State-Trait anxiety (State-Trait Anxiety Inventory), psychological stress (Perceived Stress Scale), SB across domains during weekdays and weekends (Last 7-day Sedentary Behaviour Questionnaire) and PA intensities (International Physical Activity Questionnaire) were assessed by self-report in 360 undergraduates (44% females, mean age 20.9 ± 2.93 years). A subsample (n = 121; 53.7% females; mean age 20.8 ± 2.6 years) wore an activPAL^TM to determine total SB, light, and moderate-to-vigorous intensity PA (MVPA). Self-reported MVPA was significantly associated with lower trait anxiety and perceived stress, whereas light PA was only associated with lower perceived stress. Weekend total self-reported SB was related to higher trait anxiety and perceived stress levels, while total SB during the week was not. Of all SB domains, only leisure SB (screen and non-screen based) was associated with higher trait anxiety and perceived stress. PA attenuated the negative relationships between excessive sitting time and trait anxiety but not perceived stress. No associations were found for monitor-based measures of PA and SB. No associations were found between PA or SB variables with state anxiety. Further research is needed to assess causal and reciprocal relationships between PA, SB and mental health in college students.     

Changes and challenges in the transition to adulthood: views and experiences of young people with learning disabilities and their families

The transition to adulthood poses one of the most complex challenges for young people with intellectual disabilities. In order to conduct a wide-reaching and in-depth study of this process, we need to know the views of these young people themselves and their families. This article presents research designed to collect the experiences and perceptions of young people with disabilities and their families regarding perceived problems and support in their transition to adulthood in Spain. A qualitative case study method was used to achieve this. Data were collected in three stages on the following topics: educational pathway (primary and secondary school), social support networks and free time, and construction of a personal plan for the future (labour market inclusion and independent living). Various different instruments were used, including interviews, focus groups and visual methods. As for the results, the young people who participated in the study experienced difficulties with both successfully completing secondary education and continuing their education. The families in our study were not very satisfied with the guidance received from professionals upon finishing secondary school. They also complained about the lack of training options available to young people with disabilities. The participants expressed certain fears regarding social inclusion and labour market integration. They are aware that they will need help, and have doubts about whether they will receive the necessary support to progress with their plans for labour market integration and independent living. As a result of the study, we propose several recommendations to improve opportunities for the social inclusion of young people with disabilities in their transition to adulthood.     

Students' use of the x-intercept as an instance of a transitional conception

This article uses an evolutionary perspective of conceptual change to consider in detail a conception in the domain of linear functions. The analysis focuses on the nature of students' use of the x-intercept in equations of the form y = mx + b by summarizing the results of written assessments and presenting two case studies of students exploring and discussing linear equations and their graphs. I argue that the uses of the x-intercept documented in this study are not a superficial error, a simple mismatch with convention, or a misconception. Instead, this student conception is analyzed as an instance of a ‘transitional conception:’ a conception which is the result of sense-making, reflects the complexity of the domain, is productive in some contexts, and has the potential for refinement. The participants in the study were nine pairs of ninth and tenth grade students from an exemplary first-year algebra course. These students participated in videotaped discussion sessions with a peer of their choice where they used graphing software to explore linear equations and their graphs. The discussion sessions involved problems designed on the basis of student conceptions suggested in previous research (Moschkovich, 1989; Schoenfeld, Smith & Arcavi, 1993) and in classroom observations (Moschkovich, 1990). Protocol analysis of the videotaped discussion sessions was used to explore the nature and transformation of students' conceptions in this domain. Several uses of the x-intercept were documented in the written assessments and in the videotaped discussions. I summarize the results of the written assessments and present an analysis of the discussions for two pairs of students to show that the use of the x-intercept can be framed as a ‘transitional conception’ This revised version was published online in July 2006 with corrections to the Cover Date.     

Excessively Long Editorial Decisions and Excessively Long Publication Times by Journals: Causes,Risks, Consequences,and Proposed Solutions

Editors have very complex tasks and high responsibilities. In general, they are chosen leaders and experts in a field of study. Thus, they are expected to lead a sector of that scientific community, and their function is to serve as gate-keepers of the quality of submissions to journals whose editorial boards they serve because of their ethical and professional image, and positive and open engagement with their peers. Publishing a scientific paper can be an arduous task and in some cases a lengthy one. However, any delay in this process not only serves as a form of stress for authors, it may also disadvantage them by giving their competition an unfair advantage with a head start in the publishing rat race. Consequently, editors who oversee a process that takes an excessive or unreasonable amount of time should be held accountable. In this paper, we propose some suggested time limits for each stage of the publishing process. These should be carefully monitored by the editors, in close collaboration with the publisher, to ensure a fair and timely process that is realistic and reasonable. With clearer guidelines, authors can thus reduce their stress levels by knowing when to expect decisions, and can thus make their journal selection by keeping such factors in mind, and thus hedge their risks and better manage their time. Authors who wait almost indefinitely, or for excessively long periods of time, are victims of a lack of professionalism. Furthermore, editors who fail to communicate delays, effectively or at all, or who fail to offer any sufficient or heartfelt apology should be characterized as acting with professional negligence, if not misconduct. Only when the rules of engagement are fair, strict, clear and well defined can authors expect the publishing system to progress smoothly and professionally.     

U.S. News Coverage of Global Terrorist Incidents

A slew of gruesome executions by terrorist groups in 2014–2015 renewed interest in the public relations strategies of terrorists. As a case in point, the Islamic State group’s escalating brutality reflects their efforts as a relatively nascent extremist group to ensure a high and sustained volume of media coverage, especially among Western outlets. But what characteristics of events actually prompt coverage from major U.S. news media? Using a rich data set of terrorist incidents and coverage from six major broadcast and cable U.S. networks, we model coverage of terrorist incidents as a function of event proximity from U.S. soil, target country affinity with the United States, number of total and U.S. casualties, and the characteristics of the terrorist group. Our findings largely corroborate expectations set forth by the literature on norms and routines of journalism and economics of news. When it comes to terrorism, coverage by U.S. major media outlets is largely dependent on proximity to and affinity with the United States, weapons of mass destruction, and the number of global and U.S. casualties.     

A Case of Inconsistent Equatings: How the Man With Four Watches Decides What Time It Is

A simultaneous equating of four new test forms to each other and to one previous form was accomplished through a complex design incorporating seven separate equating links. Each new form was linked to the reference form by four different paths, and each path produced a different score conversion. The procedure used to resolve these inconsistencies was applied separately at each score level. Considering each equating (at a given score level) as a simple additive increment and imposing constraints on those increments led to a system of seven equations in seven unknowns. The solution produced a set of adjusted increments, so that the linking of any new form to the reference form was the same by all four possible paths.     

Change of Emphasis in the Mathematics Assessment in Hungary

International survey data showed that Hungarian students performed well in both mathematics and science in the past. Since 1991 achievement in these 2 areas has declined, and this was most clearly shown in Third International Mathematics and Science Study (TIMSS). Two possible reasons for this phenomenon are investigated here: as a consequence of recent political and economical changes; due to the conservative structure of math and science teaching which differ from the international trend. While the achievement of Hungarian students was high on items requiring awareness of the traditional disciplines, it was lower on literacy and life-skill items and topics such as environment issues, measurement, data representation and interpretation, and so forth. Following international trends, the national monitoring surveys have shown a shift from the “academic” approach to the “real-life” application of mathematics. The paper presents both the new approach and the findings from the most recent national survey.