Media User Patterns of Adolescents in a Multimedia Environment: An Assessment of Gender and Income Differences

This study attempts to examine the changes in the media use patterns of adolescents in the changing media environment. Previous studies on media users show that gender, age, income and life styles are best predictors of media use patterns. However, this study tries to look at the changes in the influence of these factors. In the digital environment it is impossible to have a full view of the actual usage with the existing methods of measurement. This is because people use the digital media in a very distinctive way. So we adopted a qualitative method in order to fully understand the media use behavior of adolescents. FGI of 47 middle school students in the Seoul area, we found that the gender differences were not as obvious in the sense that most girls and boys use similar media content. However, in the way of usage, boys tend to be more addictive, while girls used a more diverse range of media. Boys did not show differences according to income, whereas girls behavior surrounding the media were difference among different social class. Media was a more important activity to girls, while for boys it was just one of many activities that could be shared with friends.이 연구는 2007년도 정부재원(교육인적자원부 학술연구조성사업비)으로 한국학술진흥재단의 지원을 받아 이루어졌습니다(KRF-2007-321-B00212

Reconstruction of Acetogenesis Pathway Using Short-Read Sequencing of Clostridium aceticum Genome

Clostridium aceticum is an anaerobic homoacetogen, able to reduce CO2 to multi-carbon productsusing the reductive acetyl-CoA pathway. This unique ability to use CO2 or CO makes the microbea potential platform for the biotech industry. However, the development of genetically engineeredhomoacetogen for the large-scale production of commodity chemicals is hampered by the limitedamount of their genetic and metabolic information. Here we exploited next-generation sequencingto reveal C. aceticum genome. The short-read sequencing produced 44,871,196 high quality readswith an average length of 248 bases. Following sequence trimming step, 30,256,976 reads wereassembled into 12,563 contigs with 168-fold coverage and 1,971 bases in length using de Bruijngraph algorithm. Since the k-mer hash length in the algorithm is an important factor for the qualityof output contigs, a window of k-mers (k-51 to k-201) was tested to obtain high quality contigs.In addition to the assembly metrics, the functional annotation of the contigs was investigated toselect the k-mer optimum. Metabolic pathway mapping using the functional annotation identifiedthe majority of central metabolic pathways, such as the glycolysis and TCA cycle. Further, theseanalyses elucidated the enzymes consisting of Wood–Ljungdahl pathway, in which CO2 is fixed intoacetyl-CoA. Thus, the metabolic reconstruction based on the draft genome assembly provides afoundation for the functional genomics required to engineer C. aceticu