Factorial Validity and Invariance Testing of the Exercise Dependence Scale-Revised in Swedish and Portuguese Exercisers

The present study investigated the factorial validity and factorial invariance of the 21-item Exercise Dependence Scale-Revised using 162 Swedish and 269 Portuguese exercisers. In addition, the prevalence of exercise dependence symptoms and links to exercise behavior, gender, and age in the two samples was also studied. Confirmatory factor analyses demonstrated that the hypothesized 7-factor model made a good fit to data in both samples. Multi-sample analyses supported partial measurement invariance across the samples; only factor loadings involving items 3 and 19 were noninvariant. The “Reduction in Other Activities” and “Lack of Control” factors were the most problematic scales in terms of average variance explained and reliability measures of weighted omega and Cronbach's alpha. In total, 9.2% of the Swedish sample and 5.2% of the Portuguese sample were classified as at risk for exercise dependence. Overall, the results support the factorial validity of the translated Exercise Dependence Scale-Revised in samples outside North-America, although more research is needed.     

Maximal oxygen uptake versus maximal power output in children

Abstract

Maximal oxygen uptake ([Vdot]O_2max) is considered the optimal method to assess aerobic fitness. The measurement of [Vdot]O_2max, however, requires special equipment and training. Maximal exercise testing with determination of maximal power output offers a more simple approach. This study explores the relationship between [Vdot]O_2max and maximal power output in 247 children (139 boys and 108 girls) aged 7.9–11.1 years. Maximal oxygen uptake was measured by indirect calorimetry during a maximal ergometer exercise test with an initial workload of 30 W and 15 W · min^?1 increments. Maximal power output was also measured. A sample (n = 124) was used to calculate reference equations, which were then validated using another sample (n = 123). The linear reference equation for both sexes combined was: [Vdot]O_2max (ml · min^?1) = 96 + 10.6 · maximal power + 3.5 · body mass. Using this reference equation, estimated [Vdot]O_2max per unit of body mass (ml · min^?1 · kg^?1) calculated from maximal power correlated closely with the direct measurement of [Vdot]O_2max (r = 0.91, P <0.001). Bland-Altman analysis gave a mean limits of agreement of 0.2±2.9 (ml · min^?1 · kg^?1) (1 s). Our results suggest that maximal power output serves as a good surrogate measurement for [Vdot]O_2max in population studies of children aged 8–11 years.     

The Dynamics of Professional Identity

The aim of this article is to analyse how journalists' professional identity is related to their attitude towards PR. The focus is how—and to what extent—journalistic ideology, organizational belonging and the individual's social position influence journalists' perception that other journalists working with PR lower the trustworthiness of journalism. The analyses rest on data from the Swedish Journalist Survey 2011, which is a national representative survey of Swedish journalists. The results show that journalists in general embrace a hostile attitude towards journalists who start working as PR practitioners. However, those who have worked as a journalist for fewer years or have journalistic ideals promoting the amusement function of journalism, or have worked as a freelance, or been employed in an organization producing newsletters, as well as female journalists, weaken this posture. The article concludes with a discussion on how the results could be understood in relation to recent changes in journalism's power and prerequisites, and how a professional identity might function as a form of resistance.     

Long-term microfluidic glucose and lactate monitoring in hepatic cell culture

Monitoring cellular bioenergetic pathways provides the basis for a detailed understanding of the physiological state of a cell culture. Therefore, it is widely used as a tool amongst others in the field of in vitro toxicology. The resulting metabolic information allows for performing in vitro toxicology assays for assessing drug-induced toxicity. In this study, we demonstrate the value of a microsystem for the fully automated detection of drug-induced changes in cellular viability by continuous monitoring of the metabolic activity over several days. To this end, glucose consumption and lactate secretion of a hepatic tumor cell line were continuously measured using microfluidically addressed electrochemical sensors. Adapting enzyme-based electrochemical flat-plate sensors, originally designed for human whole-blood samples, to their use with cell culture medium supersedes the common manual and laborious colorimetric assays and off-line operated external measurement systems. The cells were exposed to different concentrations of the mitochondrial inhibitor rotenone and the cellular response was analyzed by detecting changes in the rates of the glucose and lactate metabolism. Thus, the system provides real-time information on drug-induced liver injury in vitro.     

Rediscovering radiology: new technologies and remedial action at the worksite

This study contributes to social studies of imaging and visualization practices within scientific and medical settings. The focus is on practices in radiology, which are bound up with visual records known as radiographs. The study addresses work following the introduction of a new imaging technology, tomosynthesis. Since it was a novel technology, there was limited knowledge of how to correctly analyse tomosynthesis images. To address this problem, a collective review session was arranged. The purpose of the present study was to uncover the practical work that took place during that session and to show how, and on what basis, new methods, interpretations and understandings were being generated. The analysis displays how the diagnostic work on patients' bodies was grounded in two sets of technologically produced renderings. This shows how expertise is not simply a matter of providing correct explanations, but also involves discovery work in which visual renderings are made transparent. Furthermore, the results point to how the disciplinary knowledge is intertwined with timely actions, which in turn, partly rely on established practices of manipulating and comparing images. The embodied and situated reasoning that enabled radiologists to discern objects in the images thus display expertise as inherently practical and domain-specific.     

Boundary objects and curriculum change: the case of integrated versus subject-based teaching

The article examines the stability and success of ideas within pedagogical discourses. Why do certain ideas attract actors and how does change come about? These general questions are dealt with through considering the example of the swift spread of an interdisciplinary idea, arbetsområde (translated to ‘spheres of work’) in the process of a Swedish national curriculum reform 1966–1967. How did it manage to become such a central concept in the curriculum? The article uses the concept of the boundary object in order to understand the popularity of the ‘spheres of work’ concept. Boundary objects have normally been used to explain the rigidity of science, and how the heterogeneity of different actors normally involved in the production of scientific knowledge can be coordinated and result in generalizable findings. However, lately, they have been applied to the field of curriculum studies. In this study, a boundary object pinpoints the fact that curricular solutions can be about coordinating different types of actors with different stakes in the making of a curriculum.