Co-constructing controversy: content analysis of collaborative knowledge negotiation in online communities

Knowledge sharing online has flourished within organizations as well as open online communities due to the pervasiveness of Web 2.0 platforms. This paper builds on previous studies of social construction of knowledge online and investigates how contributors in online communities collaboratively share and construct controversial scientific knowledge. As the general public participates in such knowledge collaboration, understanding the processes through which they contribute content and roles that they play is imperative. The authors conducted the content analysis of three online communities that engage in knowledge collaboration on the subject of Measles, Mumps, and Rubella (MMR) vaccination, which is perceived as contentious knowledge by the public due to the widespread myth among parents that the MMR vaccine is associated with autism. The study's findings include that the content discussed is influenced by the purposes of the communities, nature of the tasks, and demographics of participants, although they discussed the same topic. The authors also found that the framework of knowledge reuse and knowledge co-construction sites is useful for investigating the content and roles that appeared in the three communities. The contribution of the paper includes the analytical framework of knowledge reuse and knowledge co-construction, articulation of the content and roles that appeared in online communities, and unboxing of discourses in three different online communities. Future research directions are also discussed.     

Effects of 10-week walking and walking with home-based resistance training on muscle quality,muscle size,and physical functional tests in healthy older individuals

Background

Older individuals have been shown to present muscle atrophy in conjunction with increased fat fraction in some muscles. The proportion of fat and connective tissue within the skeletal muscle can be estimated from axial B-mode ultrasound images using echo intensity (EI). EI was used to calculate the index of muscle quality. Walking, home-based weight-bearing resistance training, and its combinations are considered simple, easy, and practical exercise interventions for older adults. The purpose of this study was to quantify the effects of walking and walking with home-based resistance training on muscle quality of older individuals.

Methods

Thirty-one participants performed walking training only (W-group; 72?±?5?years) and 33 participants performed walking and home-based resistance training (WR-group; 73?±?6?years). This study was a non-randomized controlled trial with no control group. All participants were instructed to walk 2 or 3 sets per week for 10?weeks (one set: 30-min continuous walking). In addition, the WR-group performed home-based weight-bearing resistance training. EI was measured as a muscle quality index using axial B-mode ultrasound images of the rectus femoris and vastus lateralis of the mid-thigh. We further averaged these parameters to obtain the EI of the quadriceps femoris (QF). Participants further performed five functional tests: sit-ups, supine up, sit-to-stand, 5-m maximal walk, and 6-min walk.

Results

QF EI was significantly decreased in both groups after training (W-group 69.9?±?7.4?a.u. to 61.7?±?7.0?a.u., WR-group 64.0?±?9.5?a.u. to 51.1?±?10.0?a.u.; P?<?0.05), suggesting improved muscle quality. QF EI was further decreased in the WR-group compared with the W-group. The sit-up test in both groups and the sit-to-stand and 5-m maximal walk tests in the W-group were significantly improved after training.

Conclusion

These results suggest that training-induced stimulation is associated with a decrease in EI in some thigh regions. Furthermore, the addition of home-based resistance training to walking would be effective for a greater reduction of EI.

     

Locomotion development and infants' object interaction in a day-care environment

This longitudinal study examined the relationship between the development of locomotion and infants' interaction with others involving objects. Observations took place in a multi-person situation—a day-care class—for one-year-old infants for 1 year. The study participants were 13 infants and 7 caregivers (all Japanese). Frequencies of infants’ manual contact with objects and moving before contact with them did not differ according to locomotion developmental level. However, infants who began walking engaged in more social interactions than those who were cruising or crawling. Throughout all locomotor developmental periods, social interactions increased in frequency when more caregivers were present. As infants began to walk, they moved more prior to social interactions, had more frequent bidirectional and triadic social interactions, and moved and interacted more often with others during a single object episode. These results suggest that crawlers' engagement with objects is relatively object-oriented, while for walkers, locomotion seems to be driven by social stimuli. Infants who have begun to walk moved among caregivers and peers in a multi-person environment and developed more elaborated social interactions through objects.