Over the years, it was getting attention to hepatitis C virus (HCV) and human immu-nodeficiency virus (HIV) infection among injected drug users (IDUs) in Taiwan. This study investigated the frequency of risky behavior...Over the years, it was getting attention to hepatitis C virus (HCV) and human immu-nodeficiency virus (HIV) infection among injected drug users (IDUs) in Taiwan. This study investigated the frequency of risky behaviors for HCV carriers and IDUs who were HIV carriers in methadone maintenance treatment program. The subjects, intravenously injected heroin abusers, were collected from a special methadone maintenance treatment clinic. The survey included characteristics of participants, sexual activity and attitude towards condom usage. The total number of subjects was 151. Data were analyzed using the statistical package SPSS 15.0. The analytical methods included descriptive analysis, Fisher’s exact test, and the logistic regression model. The study showed that 82% of intravenously injected heroin abusers were hepatitis C virus (HCV)-positive, and 44.4% were hepatitis B virus (HBV)-positive;89.5% of HIV-positive heroin abusers were type C hepatitis positive. Only 21.2% of these intra-venously injected heroin abusers always used a condom, and 39.7% never used a condom during sexual activity. Logistic regression analysis showed smoking, sharing syringes needles, HBV status and condom use status were four main risk factors on HIV infection. Sharing or using contaminated syringes needles was the main cause of HIV, HBV, and HCV infection in the drug addiction group. Since our government has the policy of providing a methadone maintenance treatment program, the spread of HIV is under control, but knowledge about HIV and safe sex education still needs improvement.展开更多
Sexual selection by female choice can shape the evolution of male traits within populations, since the most attractive males experience an increase in fitness through elevated mating success. Speciation by sexual sele...Sexual selection by female choice can shape the evolution of male traits within populations, since the most attractive males experience an increase in fitness through elevated mating success. Speciation by sexual selection occurs when evolution in traits and preferences within populations causes differentiation among populations, such that females in alternative populations prefer sexual signals of their own population relative to others. Differentiated traits and preferences thereby play an active role in limiting gene flow between divergent populations. The effectiveness of differentiated preferences in maintaining differentiated male signals against the homogenizing effects of gene flow across populations will be limited by both the degree to which fe- males can discriminate against non-local males, and the breeding values of traits and preferences. Populations of the Hawaiian cricket Laupala cerasina have diverged in pulse rate, a sexually selected male signal, and female acoustic preference for pulse rate. Gene flow between neighboring populations may be reduced if migrants from sexually diverged populations experience re- duced mating success. We show that females discriminate among divergent songs characteristic of neighboring populations, that differences among populations in song and preference breed true in a common environment, and that mean preferences for each population closely match the mean pulse rates. Divergence in preference was observed only between populations that also dif- fered in song. Along with a striking ability to discriminate slight differences in song, correlated evolution of song and preference within populations could be a mechanism that promotes assortative mating among populations, thereby reducing gene flow, and leading to speciation in Laupala [Current Zoology 58 （3）： 416-425, 2012].展开更多
文摘Over the years, it was getting attention to hepatitis C virus (HCV) and human immu-nodeficiency virus (HIV) infection among injected drug users (IDUs) in Taiwan. This study investigated the frequency of risky behaviors for HCV carriers and IDUs who were HIV carriers in methadone maintenance treatment program. The subjects, intravenously injected heroin abusers, were collected from a special methadone maintenance treatment clinic. The survey included characteristics of participants, sexual activity and attitude towards condom usage. The total number of subjects was 151. Data were analyzed using the statistical package SPSS 15.0. The analytical methods included descriptive analysis, Fisher’s exact test, and the logistic regression model. The study showed that 82% of intravenously injected heroin abusers were hepatitis C virus (HCV)-positive, and 44.4% were hepatitis B virus (HBV)-positive;89.5% of HIV-positive heroin abusers were type C hepatitis positive. Only 21.2% of these intra-venously injected heroin abusers always used a condom, and 39.7% never used a condom during sexual activity. Logistic regression analysis showed smoking, sharing syringes needles, HBV status and condom use status were four main risk factors on HIV infection. Sharing or using contaminated syringes needles was the main cause of HIV, HBV, and HCV infection in the drug addiction group. Since our government has the policy of providing a methadone maintenance treatment program, the spread of HIV is under control, but knowledge about HIV and safe sex education still needs improvement.
文摘Sexual selection by female choice can shape the evolution of male traits within populations, since the most attractive males experience an increase in fitness through elevated mating success. Speciation by sexual selection occurs when evolution in traits and preferences within populations causes differentiation among populations, such that females in alternative populations prefer sexual signals of their own population relative to others. Differentiated traits and preferences thereby play an active role in limiting gene flow between divergent populations. The effectiveness of differentiated preferences in maintaining differentiated male signals against the homogenizing effects of gene flow across populations will be limited by both the degree to which fe- males can discriminate against non-local males, and the breeding values of traits and preferences. Populations of the Hawaiian cricket Laupala cerasina have diverged in pulse rate, a sexually selected male signal, and female acoustic preference for pulse rate. Gene flow between neighboring populations may be reduced if migrants from sexually diverged populations experience re- duced mating success. We show that females discriminate among divergent songs characteristic of neighboring populations, that differences among populations in song and preference breed true in a common environment, and that mean preferences for each population closely match the mean pulse rates. Divergence in preference was observed only between populations that also dif- fered in song. Along with a striking ability to discriminate slight differences in song, correlated evolution of song and preference within populations could be a mechanism that promotes assortative mating among populations, thereby reducing gene flow, and leading to speciation in Laupala [Current Zoology 58 （3）： 416-425, 2012].
