87 research outputs found

    Automatic classification using concept knowledge of web documents

    Get PDF
    In order to classify web documents, we suggest a method using concept knowledge of category.In our study, the concept relations between keywords are extracted using hyperlink information and after the extracted keywords are classified into each category, these are used as an index.Then TFIDF for each category is extended to determine index weight value.The system is constructed for experimenting and estimating,which is consist of web robot, indexer, concept knowledge database for each category and the document classifier.Our system to be applied the extended TFIDF method shows an accuracy of 88% in automatic classifying of web documents

    Relationship between sleep and obesity among U.S. and South Korean college students

    Get PDF
    Background Little is known about the relationship between sleep and obesity in young adults, particularly college students. This study examined the relationship between sleep (i.e., sleep duration and quality) and obesity in a large and diverse binational sample of college students. Methods Analyses were based on a 40-item paper survey from 2016/2017 to 2017/2018 academic years, with a 72% response rate. The samples were 1578 college students aged 18–25 years from five universities (two in the U.S. and three in South Korea). Weight and height were measured objectively; other measures (e.g., health behaviors) were self-reported. Multinomial logistic regression was used to assess the association between sleep duration and independent variables (race/nationality, gender, and BMI). Poisson regression was used to examine the relationship between sleep quality and independent variables. Results Overall, blacks had a higher adjusted odds ratio (AOR) of short sleep (\u3c 7 h/night) than whites (AOR = 1.74, P \u3c .01); overweight participants had a higher AOR of short sleep than normal weight participants (AOR = 1.52, P \u3c .01); and obese participants had a higher AORs of both short and long sleep (\u3e 9 h/night) (AOR = 1.67, P \u3c .01; AOR = 1.79, P \u3c .05, respectively). Among men, being black, overweight, and obesity were associated with short sleep (P \u3c .05), whereas only obesity was related to short sleep among women (P \u3c .05). In analyses stratified by race and nationality, overweight and obesity were related to short sleep among blacks only (P \u3c .05). Overall, sleep quality (getting enough sleep to feel rested in the morning in the past 7 days) was worse in blacks and South Koreans than whites (P \u3c .05), worse in women than men (P \u3c .05), and worse in participants with obesity than normal weight participants (P \u3c .05). Conclusions Obesity was associated with both short (\u3c 7 h/night) and long sleep duration (\u3e 9 h/night) and poor sleep quality among all participants. In comparison with whites, blacks were more like to have short sleep, and blacks and South Koreans had worse sleep quality. Further investigations using a larger sample of college students in multiple countries may be helpful to identify target populations who are at a greater risk of obesity and sleep problems

    Carbon nanotube/Co3O4 composite for air electrode of lithium-air battery

    Get PDF
    A carbon nanotube [CNT]/Co3O4 composite is introduced as a catalyst for the air electrode of lithium-air [Li/air] batteries. Co3O4 nanoparticles are successfully attached to the sidewall of the CNT by a hydrothermal method. A high discharge capacity and a low overvoltage indicate that the CNT/Co3O4 composite is a very promising catalyst for the air electrode of Li/air batteries

    Relationship between sleep and obesity among U.S. and South Korean college students

    Get PDF
    Background Little is known about the relationship between sleep and obesity in young adults, particularly college students. This study examined the relationship between sleep (i.e., sleep duration and quality) and obesity in a large and diverse binational sample of college students. Methods Analyses were based on a 40-item paper survey from 2016/2017 to 2017/2018 academic years, with a 72% response rate. The samples were 1578 college students aged 18–25 years from five universities (two in the U.S. and three in South Korea). Weight and height were measured objectively; other measures (e.g., health behaviors) were self-reported. Multinomial logistic regression was used to assess the association between sleep duration and independent variables (race/nationality, gender, and BMI). Poisson regression was used to examine the relationship between sleep quality and independent variables. Results Overall, blacks had a higher adjusted odds ratio (AOR) of short sleep ( 9 h/night) (AOR = 1.67, P < .01; AOR = 1.79, P < .05, respectively). Among men, being black, overweight, and obesity were associated with short sleep (P < .05), whereas only obesity was related to short sleep among women (P < .05). In analyses stratified by race and nationality, overweight and obesity were related to short sleep among blacks only (P < .05). Overall, sleep quality (getting enough sleep to feel rested in the morning in the past 7 days) was worse in blacks and South Koreans than whites (P < .05), worse in women than men (P < .05), and worse in participants with obesity than normal weight participants (P < .05). Conclusions Obesity was associated with both short ( 9 h/night) and poor sleep quality among all participants. In comparison with whites, blacks were more like to have short sleep, and blacks and South Koreans had worse sleep quality. Further investigations using a larger sample of college students in multiple countries may be helpful to identify target populations who are at a greater risk of obesity and sleep problems

    Heterologous expression of tylosin polyketide synthase and production of a hybrid bioactive macrolide in Streptomyces venezuelae

    Full text link
    Tylosin polyketide synthase (Tyl PKS) was heterologously expressed in an engineered strain of Streptomyces venezuelae bearing a deletion of pikromycin PKS gene cluster using two compatible low-copy plasmids, each under the control of a pikAI promoter. The mutant strain produced 0.5 mg/l of the 16-membered ring macrolactone, tylactone, after a 4-day culture, which is a considerably reduced culture period to reach the maximum production level compared to other Streptomyces hosts. To improve the production level of tylactone, several precursors for ethylmalonyl-CoA were fed to the growing medium, leading to a 2.8-fold improvement (1.4 mg/ml); however, switching the pikAI promoter to an actI promoter had no observable effect. In addition, a small amount of desosamine-glycosylated tylactone was detected from the extract of the mutant strain, revealing that the native glycosyltransferase DesVII displayed relaxed substrate specificity in accepting the 16-membered ring macrolactone to produce the glycosylated tylactone. These results demonstrate a successful attempt for a heterologous expression of Tyl PKS in S. venezuelae and introduce S. venezuelae as a rapid heterologous expression system for the production of secondary metabolites.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45861/1/253_2006_Article_318.pd
    corecore