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31.
Fuchs (2010 Fuchs, C. 2010. Labor in information capitalism and on the Internet. The Information Society 26:179196.[Taylor & Francis Online], [Web of Science ®] [Google Scholar], 2012 Fuchs, C. 2012. With or without Marx? With or without capitalism?: A re-joinder to Adam Arvidsson and Eleanor Colleoni. tripleC 10 (2):63345. [Google Scholar]) argues that users of social media produce value and surplus value in the Marxian sense. Arvidsson and Colleoni (2012 Arvidsson, A., and E. Colleoni. 2012. Value in information capitalism and on the Internet. The Information Society 28:13550.[Taylor & Francis Online], [Web of Science ®] [Google Scholar]) critique this hypothesis, claiming that Marx's theory of value is irrelevant to the regime of value production on social media platforms in particular and in informational capitalism in general. They claim that the affective relations and financial speculations that generate value on social media are not dependent on labor time. This article critically engages Fuchs, and Arvidsson and Colleoni, by revisiting Marx's theory of value. Contra Fuchs, we argue that audiences do not produce value and surplus value—neither for social nor for mass media. Contra Arvidsson and Colleoni, we argue that so-called affective relations (philia) do not produce value either. Instead we demonstrate that social media generate revenue from four primary sources—by leasing advertisement space to generate advertisement rent, by selling information, by selling services to advertisers, and by generating profits from fictitious capital and speculative windfalls. All four, we argue, can be adequately explained by Marx's theory of value.  相似文献   
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Today’s working life is increasingly characterized by entrepreneurial challenges. Entrepreneurial challenges start at an individual level with the identification of entrepreneurial opportunities, which is acknowledged as one of the key competencies for lifelong learning. Since the identification of entrepreneurial opportunities relies heavily on the opportunity identification competence (OIC) of individuals, understanding the meaning of OIC is relevant. Until now, OIC has been explored in the young entrepreneurship research field. However, entrepreneurship researchers until now have not fully explored OIC. According to several authors, the research on complex problem solving (CPS) in the cognitive research field might contribute to understanding OIC. In this paper, we review the link between OIC and CPS by comparing the cognitive and entrepreneurship research fields. We argue that those who excel in identifying opportunities share core characteristics with high-level complex problem-solvers. We propose to conduct empirical research in the future to investigate the relation between OIC and CPS within a work context in order to gain more insight into OIC. We believe that the cognitive research field contributes to the entrepreneurship research field and provides a deeper understanding of the initial steps of the entrepreneurial process.  相似文献   
33.
This investigation examined effects of two exercise modes (barbell, BB; bodyweight suspension, BWS) on muscle activation, resistance load, and fatigue. During session one, nine resistance-trained males completed an elbow flexion one-repetition maximum (1RM). During sessions two and three, subjects completed standing biceps curls to fatigue at 70% 1RM utilizing a randomized exercise mode. Surface electromyography (sEMG) recorded muscle activation of the biceps brachii, triceps brachii, anterior deltoid, posterior deltoid, rectus abdominis, and erector spinae. BWS resistance load was measured using a force transducer. Standing maximal voluntary isometric contractions of the elbow flexors recorded at 90° were used to determine the isometric force decrement and rate of fatigue (ROF) during exercise. sEMG and resistance load data were divided into 25% contraction duration bins throughout the concentric phase. BWS resulted in a 67.7?±?7.4% decline in resistance load throughout the concentric phase (p?≤?0.05). As a result, BB elicited higher mean resistance loads (31.4?±?4.0?kg) and biceps brachii sEMG (84.7?±?27.8% maximal voluntary isometric contractions, MVIC) compared with BWS (20.4?±?3.4?kg, 63.4?±?21.6% MVIC). No difference in rectus abdominis or erector spinae sEMG was detected between exercise modes. Isometric force decrement was greater during BWS (?21.7?±?7.0?kg) compared with BB (?14.9?±?4.7?kg); however, BB (?3.0?±?0.8?kg/set) resulted in a steeper decline in ROF compared with BWS (?1.7?±?0.6?kg/set). The variable resistance loading and greater isometric force decrement observed suggest that select BWS exercises may resemble variable resistance exercise more than previously considered.  相似文献   
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This article considers the emergence of classroom wall charts as a teaching technology in Swedish elementary schools in the late nineteenth and early twentieth centuries, using Biblical history teaching as an example. There has been some work done internationally on wall charts as an instructional technology, but few studies have looked at their use in Sweden. With a theoretical approach informed by Martin Lawn’s understanding of teaching technologies, this article shows that wall charts became both an important teaching object and a means of introducing new pedagogical ideas. A study of the official school inspectors’ reports shows that wall charts had spread to most local schools by the end of the nineteenth century, while an analysis of Biblical history textbooks and teaching guidelines shows that visual aids were increasingly integrated into the school curriculum. The wall charts themselves were initially imported, mainly from Germany, but by the end of the nineteenth century they were being produced in Sweden for the domestic market, in keeping with the National Romantic ideals of the day as well as with the new awareness of the importance of adapting images to use in classroom teaching.  相似文献   
35.
Because body mass change (ΔMb) does not represent all water losses and gains, the present field investigation determined if (a) ΔMb equalled the net effective body water change during ultra-endurance exercise and (b) ground speed and exercise duration influenced these variables. Thirty-two male cyclists (age range, 35–52 years) completed a 164-km event in a hot environment, were retrospectively triplet matched and placed into one of three groups based on exercise duration (4.8, 6.3, 9.6 h). Net effective body water loss was computed from measurements (body mass, total fluid intake and urine excreted) and calculations (water evolved and mass loss due to substrate oxidation, solid food mass and sweat loss), including (ΔEBWgly) and excluding (ΔEBW) water bound to glycogen. With all cyclists combined, the mean ΔMb (i.e. loss) was greater than that of ΔEBWgly by 1200 ± 200 g (P = 1.4 × 10–18), was similar to ΔEBW (difference, 0 ± 200 g; P = .21) and was strongly correlated with both (R2 = .98). Analysis of equivalence indicated that ΔMb was not equivalent to ΔEBWgly, but was equivalent to ΔEBW. Due to measurement complexity, we concluded that (a) athletes will not calculate the effective body water calculations routinely and (b) body mass change remains a useful field-expedient estimate of net effective body water change.  相似文献   
36.
While most studies on diverse organizations have been directed at business organizations, the academic sector has also become increasingly international and heterogeneous. Few large-scale studies have investigated multicultural academic departments and none of those have dealt with diversity and group processes. Therefore, a survey was directed towards academics in 16 science departments in three large universities in Denmark. Results based on the response from 489 academics showed that cultural diversity, as a deep level heterogeneity, was positively related to performance and satisfaction, whereas gender diversity, as a surface level heterogeneity, was negatively associated with satisfaction. Implications of these findings are discussed in detail.  相似文献   
37.
A new, simple classroom technique helps cell biology students understand principles of Michaelis-Menten enzyme kinetics. A student mimics the enzyme and the student's hand represents the enzyme's active site. The catalytic event is the transfer of marbles (substrate molecules) by hand from one plastic container to another. As predicted, increases in marble concentration increase the number of marbles transferred per unit time (initial rate, V(0)) until the turnover number becomes rate limiting and V(0) approaches the maximum velocity (V(max)), as described by the Michaelis-Menten equation. With this demonstration, students visualize an important concept: the turnover number is constant and independent of marble concentration. A student assessment of this exercise showed that it helped students visualize the turnover number and V(max) but not K(m), the marble concentration at which V(0) is one-half V(max). To address the concept of K(m), we use supplemental laboratory and lecture exercises. This exercise with plastic containers and marbles is equally suited to demonstrate the kinetics of carrier-mediated membrane transport. We conclude that this exercise helps students visualize the turnover number and V(max) and gives students important insights into the kinetic parameters used to characterize the catalytic activity of enzymes and membrane transporters.  相似文献   
38.
This study compared the muscular activation of the pectoralis major, anterior deltoid and triceps brachii during a free-weight barbell bench press performed at 0°, 30°, 45° and –15° bench angles. Fourteen healthy resistance trained males (age 21.4 ± 0.4 years) participated in this study. One set of six repetitions for each bench press conditions at 65% one repetition maximum were performed. Surface electromyography (sEMG) was utilised to examine the muscular activation of the selected muscles during the eccentric and concentric phases. In addition, each phase was subdivided into 25% contraction durations, resulting in four separate time points for comparison between bench conditions. The sEMG of upper pectoralis displayed no difference during any of the bench conditions when examining the complete concentric contraction, however differences during 26–50% contraction duration were found for both the 30° [122.5 ± 10.1% maximal voluntary isometric contraction (MVIC)] and 45° (124 ± 9.1% MVIC) bench condition, resulting in greater sEMG compared to horizontal (98.2 ± 5.4% MVIC) and –15 (96.1 ± 5.5% MVIC). The sEMG of lower pectoralis was greater during –15° (100.4 ± 5.7% MVIC), 30° (86.6 ± 4.8% MVIC) and horizontal (100.1 ± 5.2% MVIC) bench conditions compared to the 45° (71.9 ± 4.5% MVIC) for the whole concentric contraction. The results of this study support the use of a horizontal bench to achieve muscular activation of both the upper and lower heads of the pectoralis. However, a bench incline angle of 30° or 45° resulted in greater muscular activation during certain time points, suggesting that it is important to consider how muscular activation is affected at various time points when selecting bench press exercises.  相似文献   
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