Coital Experience Among Adolescents in Three Social-Educational Groups in Urban Chiang Mai, Thailand

This article compares coital experience of Chiang Mai 17–20-year-olds who were: (1) out-of-school; (2) studying at vocational schools; and (3) studying at general schools or university. Four-fifths, two-thirds and one-third, respectively, of males in these groups had had intercourse, compared to 53, 62 and 15 per cent of females. The gender difference for general school/university students, but not vocational school students, probably reflects HIV/AIDS refocusing male sexual initiation away from commercial sex workers. Vocational school females may have been disproportionately affected. Loss of virginity was associated, for both sexes, with social-educational background and lifestyle, and was less likely in certain minority ethnic groups. Among males, it was also associated with age and parental marital dissolution, and among females, with independent living and parental disharmony. Within social-educational groups, lifestyle variables dominated, but among general school/university students, parental marital dissolution (for males) and disharmony (for females) were also important, and Chinese ethnicity deterred male sexual experimentation

Harmful Elements in Estuarine and Coastal Systems

Estuaries and coastal zones are dynamic transitional systems which provide many economic and ecological benefits to humans, but also are an ideal habitat for other organisms as well. These areas are becoming contaminated by various anthropogenic activities due to a quick economic growth and urbanization. This chapter explores the sources, chemical speciation, sediment accumulation and removal mechanisms of the harmful elements in estuarine and coastal seawaters. It also describes the effects of toxic elements on aquatic flora and fauna. Finally, the toxic element pollution of the Venice Lagoon, a transitional water body located in the northeastern part of Italy, is discussed as a case study, by presenting the procedures adopted to measure the extent of the pollution, the impacts on organisms and the restoration activities

Effects of <em>Ulva lactuca</em> and <em>Sargassum cinereum</em> supplemented diets on haematological parameters and survival of Koi carp (<em>Cyprinus carpio</em> L.) against bacterial pathogen (<em>Aeromonas</em> species)

The objective of the present study was to determine effects of Ulva lactuca and Sargassum cinereum supplemented diets on some selected blood parameters and survival of fry stage Koi carp (Cyprinus carpio Linnaeus, 1758). Fish were fed Ulva lactuca diet (T1), Sargassum cinereum diet (T2) and Control diet (C) for 14 weeks. Haematological parameters were measured at the end of the indoor experiment. Total erythrocyte count (TEC), total leucocyte count (TLC) and thrombocyte count were in the range of 1.44-1.49×106 /mm3, 5.30-6.01×104 /mm3 and 2.05-2.48×104 /mm3 respectively. Thrombocyte count and TLC in T1 and T2 were significantly higher (p&lt;0.05) than the control. A challenge-test was conducted to determine their survival against Aeromonas species. Two treatments (T1, T2) and the control (C) were included into experimental setup in triplicates and each treatment consisted with two groups; saline injected and bacteria injected groups. For each replicate eight healthy Koi carps were introduced. It was revealed that survivorship curves and median survival of seaweed supplemented treatments were significantly higher (p&lt;0.05) from C. The highest survival percentage (25%) in the challenge-test was recorded in T2 at the censored point after 6 hours