Importance, Cohesion and Structural Equivalence in the Evolving Citation Network of the International Journal of Research in Marketing

The citation network of the International Journal of Research in Marketing (IJRM) is examined from 1981 to 1995. We propose a model that contains log-linear and logmultiplicative terms to estimate simultaneously the importance, cohesion, and structural equivalence of journals in the network across time. Our findings show that the overall importance of IJRM in its network is low but growing. The importance of psychology journals in the network appears to be decreasing. Clear cohesive and structurally equivalent groups of core marketing, methodology, managerial and psychology journals with distinct functions in the network are identified. Recommendations for future citation research are offered.Citation analysis;social networks;log-multiplicative models

Gene identification for the cblD defect of vitamin B12 metabolism

Background Vitamin B12 (cobalamin) is an essential cofactor in several metabolic pathways. Intracellular conversion of cobalamin to its two coenzymes, adenosylcobalamin in mitochondria and methylcobalamin in the cytoplasm, is necessary for the homeostasis of methylmalonic acid and homocysteine. Nine defects of intracellular cobalamin metabolism have been defined by means of somatic complementation analysis. One of these defects, the cblD defect, can cause isolated methylmalonic aciduria, isolated homocystinuria, or both. Affected persons present with multisystem clinical abnormalities, including developmental, hematologic, neurologic, and metabolic findings. The gene responsible for the cblD defect has not been identified. Methods We studied seven patients with the cblD defect, and skin fibroblasts from each were investigated in cell culture. Microcell-mediated chromosome transfer and refined genetic mapping were used to localize the responsible gene. This gene was transfected into cblD fibroblasts to test for the rescue of adenosylcobalamin and methylcobalamin synthesis. Results The cblD gene was localized to human chromosome 2q23.2, and a candidate gene, designated MMADHC (methylmalonic aciduria, cblD type, and homocystinuria), was identified in this region. Transfection of wild-type MMADHC rescued the cellular phenotype, and the functional importance of mutant alleles was shown by means of transfection with mutant constructs. The predicted MMADHC protein has sequence homology with a bacterial ATP-binding cassette transporter and contains a putative cobalamin binding motif and a putative mitochondrial targeting sequence. Conclusions Mutations in a gene we designated MMADHC are responsible for the cblD defect in vitamin B12 metabolism. Various mutations are associated with each of the three biochemical phenotypes of the disorder

The effects of social information on the enjoyment of online videos: An eye tracking study on the role of attention

Recent experiments showed that the valence of user comments (i.e., social information) presented alongside online videos can alter viewers’ enjoyment of videos. However, it is unclear how much attention video viewers pay to social information and whether the effects found in previous studies occur if participants are not forced to view the social information. Therefore, this study investigated how the valence of social information presented alongside online videos affects viewers’ enjoyment when viewers are free to determine whether and how much attention they pay to social information. Using an eye tracker, we found that most video viewers pay attention to social information which then elicits a valence effect on their enjoyment. Results also showed that a negativity bias occurred: Participants paid most attention to negative social information. Accordingly, the effect of social information on enjoyment was stronger for negative social information. This study is the first to show that social information of online videos affects the experiences of video viewers in settings where viewers are in charge of how much attention they pay to social information

A social identity perspective on the effect of social information on online video enjoyment

To date, videos are often presented on social media platforms where they are accompanied by social information in the form of user comments. Research suggests that this social information can alter viewers’ video enjoyment. The present study aimed to learn more about two factors that may enhance this effect by conducting a 2x2 between-subjects experiment with a control group (N = 290, Mage = 20.82, SDage = 2.49) in the Netherlands. First, we investigated the role that the source of social information (i.e., in-group vs. out-group) plays in the effect of social information. Second, we explored how writing a comment while watching a video (i.e., commenting vs. no commenting) may alter the effect of the source of social information. Results indicated that social information created by in-group members is more influential than social information created by out-group members. However, writing a comment did not increase viewers’ susceptibility to the effects of social information. These results are discussed in light of the social identity framework, leading to new insights into what may bolster the effect of social information on video enjoyment when individuals watch videos presented on social media

Scaling of polymers in aligned rods

We study the behavior of self avoiding polymers in a background of vertically aligned rods that are either frozen into random positions or free to move horizontally. We find that in both cases the polymer chains are highly elongated, with vertical and horizontal size exponents that differ by a factor of 3. Though these results are different than previous predictions, our results are confirmed by detailed computer simulations.Comment: 4 pages, 4 figure