Why Users Share the News: A Theory of Reasoned Action-Based Study on the Antecedents of News-Sharing Behavior     

Veronika Karnowski  Larissa Leonhard  Anna Sophie Kümpel 《Communication Research Reports》2018,35(2):91-100

Social media have become an integral part of online news use, affecting how individuals find, consume, and share news. By applying the Theory of Reasoned Action (TRA), this study investigates the effects of motives, attitude, and intention on news-sharing behavior among German social media users (n = 333). Findings show that news-sharing attitude and subjective norms have a positive effect on news-sharing intention, which in turn has a positive effect on actual news-sharing behavior. Taken together, we see that a new media behavior in the early phases of its societal diffusion—like social media news sharing in Germany in 2015—can mainly be explained by a rational choice logic and is rooted in the motives of socializing and information seeking. This finding thus reflects the double nature of social media as a means for both information retrieval and social grooming.  相似文献   

Development and validation of the Perceived Game-Specific Soccer Competence Scale     

Hannele Forsman  Arto Gråstén  Minna Blomqvist  Keith Davids  Jarmo Liukkonen  Niilo Konttinen 《Journal of sports sciences》2016,34(14):1319-1327

ABSTRACT

The objective of this study was to create a valid, self-reported, game-specific soccer competence scale. A structural model of perceived competence, performance measures and motivation was tested as the basis for the scale. A total of 1321 soccer players (261 females, 1060 males) ranging from 12 to 15 years (13.4 ± 1.0 years) participated in the study. They completed the Perceived Game-Specific Soccer Competence Scale (PGSSCS), self-assessments of tactical skills and motivation, as well as technical and speed and agility tests. Results of factor analyses, tests of internal consistency and correlations between PGSSCS subscales, performance measures and motivation supported the reliability and validity of the PGSSCS. The scale can be considered a suitable instrument to assess perceived game-specific competence among young soccer players.  相似文献   

Development of perceived competence,tactical skills,motivation, technical skills,and speed and agility in young soccer players     

Hannele Forsman  Arto Gråstén  Minna Blomqvist  Keith Davids  Jarmo Liukkonen  Niilo Konttinen 《Journal of sports sciences》2016,34(14):1311-1318

ABSTRACT

The objective of this 1-year, longitudinal study was to examine the development of perceived competence, tactical skills, motivation, technical skills, and speed and agility characteristics of young Finnish soccer players. We also examined associations between latent growth models of perceived competence and other recorded variables. Participants were 288 competitive male soccer players ranging from 12 to 14 years (12.7 ± 0.6) from 16 soccer clubs. Players completed the self-assessments of perceived competence, tactical skills, and motivation, and participated in technical, and speed and agility tests. Results of this study showed that players’ levels of perceived competence, tactical skills, motivation, technical skills, and speed and agility characteristics remained relatively high and stable across the period of 1 year. Positive relationships were found between these levels and changes in perceived competence and motivation, and levels of perceived competence and speed and agility characteristics. Together these results illustrate the multi-dimensional nature of talent development processes in soccer. Moreover, it seems crucial in coaching to support the development of perceived competence and motivation in young soccer players and that it might be even more important in later maturing players.  相似文献   

Microanalytical identification of Pb-Sb-Sn yellow pigment in historical European paintings and its differentiation from lead tin and Naples yellows   总被引：1，自引：1，他引：0  

David Hradil  Tom&#x; Grygar  Janka Hradilov  Petr Bezdi ka  Veronika Gr&#x;nwaldov  Igor Foga&#x;  Costanza Miliani 《Journal of Cultural Heritage》2007,8(4):377-386

The work is focused on identification of lead tin yellow types I and II, Naples yellow, and also on discrimination of a less common, distinct yellow pigment, the ternary Pb-Sb-Sn oxide.The knowledge about all those Pb-based yellows was in fact forgotten after introduction of modern synthetic yellows in 19th century. As late as in the last decade of the 20th century, the existence of Pb-Sb-Sn yellow and its production have been rediscovered, and only then it has been identified in colour layer of artworks.Pb-Sb-Sn yellow has recently been identified in colour layer of 17th century Italian paintings by Sandalinas and Ruiz-Moreno [C. Sandalinas, S. Ruiz-Moreno, Lead tin-antimony yellow, historical manufacture, molecular characterization and identification in seventeenth-century Italian paintings, Stud. Conserv. 49 (2003) 41–52], and here we report the finding of this pigment in Mid-European painting of the 18th and 19th centuries. Lead tin yellows, lead antimony yellow (Naples yellow), and lead antimony tin yellow were synthesized in laboratory following historical recipes, their colour was analyzed, and their structure was confirmed to provide a basis for their routine identification in microsamples of artworks by X-ray microdiffraction. Unequivocal identification of Pb-based yellows could help in authentication of traditional European paintings, because their use was temporally and also geographically specific. Combination of elemental microanalysis (X-ray fluorescence electron microanalysis) and X-ray powder microdiffraction were found very efficient in the microanalysis of colour layers of artworks with Pb-based yellows and their unequivocal identification.  相似文献   

Relationships between anthropometric measures and athletic performance,with special reference to repeated-sprint ability,in the Qatar national soccer team     

Franck Brocherie  Olivier Girard  Fabricio Forchino  Hani Al Haddad  Gilvan A. Dos Santos  Grégoire P. Millet 《Journal of sports sciences》2014,32(13):1243-1254

Abstract

The aim of this study was to determine potential relationships between anthropometric parameters and athletic performance with special consideration to repeated-sprint ability (RSA). Sixteen players of the senior male Qatar national soccer team performed a series of anthropometric and physical tests including countermovement jumps without (CMJ) and with free arms (CMJwA), straight-line 20 m sprint, RSA (6 × 35 m with 10 s recovery) and incremental field test. Significant (P < 0.05) relationships occurred between muscle-to-bone ratio and both CMJs height (r ranging from 0.56 to 0.69) as well as with all RSA-related variables (r < –0.53 for sprinting times and r = 0.54 for maximal sprinting speed) with the exception of the sprint decrement score (S_dec). The sum of six skinfolds and adipose mass index were largely correlated with S_dec (r = 0.68, P < 0.01 and r = 0.55, P < 0.05, respectively) but not with total time (TT, r = 0.44 and 0.33, P > 0.05, respectively) or any standard athletic tests. Multiple regression analyses indicated that muscular cross-sectional area for mid-thigh, adipose index, straight-line 20 m time, maximal sprinting speed and CMJwA are the strongest predictors of S_dec (r² = 0.89) and TT (r² = 0.95) during our RSA test. In the Qatar national soccer team, players’ power-related qualities and RSA are associated with a high muscular profile and a low adiposity. This supports the relevance of explosive power for the soccer players and the larger importance of neuromuscular qualities determining the RSA.  相似文献   

Reporting Mobile Social Media Use: How Survey and Experience Sampling Measures Differ     

Teresa K. Naab  Veronika Karnowski  Daniela Schlütz 《Communication methods and measures》2019,13(2):126-147

Quantifying the ubiquitous, ephemeral, and highly diverse patterns of mobile social media (MSM) use is a challenge for communication research. Most researchers employ retrospective survey measurement, thus depending on the accuracy of users’ memories and generalizations. Alternatively, some researchers rely on in-situ measurement, being less dependent on users’ memories and generalizations, but requiring random situation samples. To assess differences and similarities between these two measurement approaches we analyzed whether characteristics (duration and frequency of a usage episode, habit, elaboration, and gratifications) of MSM use (regarding Facebook, WhatsApp, and YouTube) vary between retrospective survey and mobile experience sampling measurement. We observe a consistent pattern of higher estimates in retrospect as compared to individual averages of in-situ reports. The absolute magnitude of these differences varies considerably between platforms and characteristics studied. Nonetheless, for most constructs and platforms we find low significant positive correlations between retrospective and aggregated in-situ values.  相似文献   

The importance of appropriate problems in the teaching of mathematics     

E. Georgescu-Buzāu  N. Matei  Gr. Bānescu 《Educational Studies in Mathematics》1970,2(4):430-437

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Cinematic Rendering in Anatomy: A Crossover Study Comparing a Novel 3D Reconstruction Technique to Conventional Computed Tomography     

Johannes S. Binder  Michael Scholz  Stephan Ellmann  Michael Uder  Robert Grützmann  Georg F. Weber  Christian Krautz 《Anatomical sciences education》2021,14(1):22-31

Integration of medical imaging into preclinical anatomy courses is already underway in many medical schools. However, interpretation of two-dimensional grayscale images is difficult and conventional volume rendering techniques provide only images of limited quality. In this regard, a more photorealistic visualization provided by Cinematic Rendering (CR) may be more suitable for anatomical education. A randomized, two-period crossover study was conducted from July to December 2018, at the University Hospital of Erlangen, Germany to compare CR and conventional computed tomography (CT) imaging for speed and comprehension of anatomy. Sixteen students were randomized into two assessment sequences. During each assessment period, participants had to answer 15 anatomy-related questions that were divided into three categories: parenchymal, musculoskeletal, and vascular anatomy. After a washout period of 14 days, assessments were crossed over to the respective second reconstruction technique. The mean interperiod differences for the time to answer differed significantly between the CR–CT sequence (−204.21 ± 156.0 seconds) and the CT–CR sequence (243.33 ± 113.83 seconds; P < 0.001). Overall time reduction by CR was 65.56%. Cinematic Rendering visualization of musculoskeletal and vascular anatomy was higher rated compared to CT visualization (P < 0.001 and P = 0.003), whereas CT visualization of parenchymal anatomy received a higher scoring than CR visualization (P < 0.001). No carryover effects were observed. A questionnaire revealed that students consider CR to be beneficial for medical education. These results suggest that CR has a potential to enhance knowledge acquisition and transfer from medical imaging data in medical education.  相似文献   

Emergence and evolution of informal roles during a canoe expedition     

Jeremie M. Carreau  Grégoire Bosselut  Stephen D. Ritchie  Jean-Philippe Heuzé  Scott Arppe 《Journal of Adventure Education & Outdoor Learning》2016,16(3):191-205

This exploratory study was conducted to illuminate aspects relevant to the emergence and evolution of informal roles in a group during a canoe expedition. Following tenets of ethnography, the first author collected observational and interview (conversational and focus group) data while participating as a member of the expedition. Three general dimensions were revealed with regards to emerging and evolving informal roles: context aspects; role occupant aspects; and group member aspects. Informal roles were found to be important structural components which contributed to group productivity and harmony. Findings are discussed in relation to the broader literature while questions are raised regarding how informal roles have been conceptualized. Implications include considering how informal roles relate to individual (e.g. satisfaction) and group (e.g. cohesion) level constructs and how outdoor leaders may benefit from understanding how informal roles emerge and evolve.  相似文献   

Polyelectrolyte multilayer surface functionalization of poly(dimethylsiloxane) (PDMS) for reduction of yeast cell adhesion in microfluidic devices     

Schmolke H  Demming S  Edlich A  Magdanz V  Büttgenbach S  Franco-Lara E  Krull R  Klages CP 《Biomicrofluidics》2010,4(4):44113

Polyelectrolyte multilayers (PEMs) based on the combinations poly(diallyldimethylammonium chloride)∕poly(acrylic acid) (PDADMAC∕PAA) and poly(allylamine hydrochloride)∕PAA (PAH∕PAA) were adsorbed on poly(dimethylsiloxane) (PDMS) and tested for nonspecific surface attachment of hydrophobic yeast cells using a parallel plate flow chamber. A custom-made graft copolymer containing poly(ethylene glycol) (PEG) side chains (PAA-g-PEG) was additionally adsorbed on the PEMs as a terminal layer. A suitable PEM modification effectively decreased the adhesion strength of Saccharomyces cerevisiae DSM 2155 to the channel walls. However, a further decrease in initial cell attachment and adhesion strength was observed after adsorption of PAA-g-PEG copolymer onto PEMs from aqueous solution. The results demonstrate that a facile layer-by-layer surface functionalization from aqueous solutions can be successfully applied to reduce cell adhesion strength of S. cerevisiae by at least two orders of magnitude compared to bare PDMS. Therefore, this method is potentially suitable to promote planktonic growth inside capped PDMS-based microfluidic devices if the PEM deposition is completed by a dynamic flow-through process.  相似文献