Combined and single effects of pesticide carbaryl and toxic Microcystis aeruginosa on the life history of Daphnia pulicaria

The combined influence of a pesticide (carbaryl) and a cyanotoxin (microcystin LR) on the life history of Daphnia pulicaria was investigated. At the beginning of the experiments animals were pulse exposed to carbaryl for 24 h and microcystins were delivered bound in Microcystis’ cells at different, sub-lethal concentrations (chronic exposure). In order to determine the actual carbaryl concentrations in the water LC–MS/MS was used. For analyses of the cyanotoxin concentration in Daphnia’s body enzyme-linked immunosorbent assay (ELISA) was used. Individual daphnids were cultured in a flow-through system under constant light (16 h of light: 8 h of dark), temperature (20°C), and food conditions (Scenedesmus obliquus, 1 mg of C l−1). The results showed that in the treatments with carbaryl egg numbers per female did not differ significantly from controls, but the mortality of newborns increased significantly. Increasing microcystin concentrations significantly delayed maturation, reduced size at first reproduction, number of eggs, and newborns. The interaction between carbaryl and Microcystis was highly significant. Animals matured later and at a smaller size than in controls. The number of eggs per female was reduced as well. Moreover, combined stressors caused frequent premature delivery of offspring with body deformations such as dented carapax or an undeveloped heart. This effect is concluded to be synergistic and could not be predicted from the effects of the single stressors.

The effectiveness of a web-based brief alcohol intervention in reducing heavy drinking among adolescents aged 15-20 years with a low educational background: a two-arm parallel group cluster randomized controlled trial

Contains fulltext : 116719.pdf (publisher's version ) (Open Access)Background To evaluate the slightly modified version of the web-based brief alcohol intervention “What Do You Drink” (WDYD) among heavy drinking adolescents and young adults aged 15–20 years with a low educational background at one and six months follow-up. Methods A two-arm parallel group cluster randomized controlled trial was conducted online in the Netherlands in 2011–2012. Participants included in the trial were recruited from preparatory and secondary vocational education institutions and had to be between 15 and 20 years of age and report heavy drinking in the past six months. In total, 73 classes representing 609 (59.9% male) participants were allocated to the experimental condition (37 classes, 318 participants: WDYD intervention) or control condition (36 classes, 291 participants: no intervention). Outcomes were heavy drinking, weekly alcohol consumption, and frequency of binge drinking. Results Regressions analyses revealed no significant main intervention effects on any of the alcohol outcomes at one and six month’s follow-up according to the intention-to-treat principle. Additionally, there were no moderating effects of gender, age, educational level, and readiness to change on the relation between the WDYD intervention and the alcohol outcomes at follow-up. Conclusions The WDYD intervention was not effective in reducing alcohol consumption among heavy drinking adolescents and young adults aged 15–20 years with a low educational background at one and six months follow-up. However, the absence of intervention effectiveness cannot be used as an argument for not conducting these types of interventions with low educated individuals, since our study was the first to target this population.11 p

The effectiveness of a web-based brief alcohol intervention in reducing heavy drinking among adolescents aged 15 to 20 years with a low educational background: Study protocol for a randomized controlled trial

Contains fulltext : 102984.pdf (publisher's version ) (Open Access)Background: The serious negative health consequences of heavy drinking among adolescents is cause for concern, especially among adolescents aged 15 to 20 years with a low educational background. In the Netherlands, there is a lack of alcohol prevention programs directed to the drinking patterns of this specific target group. The study described in this protocol will test the effectiveness of a web-based brief alcohol intervention that aims to reduce alcohol use among heavy drinking adolescents aged 15 to 20 years with a low educational background. Methods/design: The effectiveness of the What Do You Drink (WDYD) web-based brief alcohol intervention will be tested among 750 low-educated, heavy drinking adolescents. It will use a two-arm parallel group cluster randomized controlled trial. Classes of adolescents from educational institutions will be randomly assigned to either the experimental (n = 375: web-based brief alcohol intervention) or control condition (n = 375: no intervention). Primary outcomes measures will be: 1) the percentage of participants who drink within the normative limits of the Dutch National Health Council for low-risk drinking, 2) reductions in mean weekly alcohol consumption, and 3) frequency of binge drinking. The secondary outcome measures include the alcohol-related cognitions, attitudes, self-efficacy, and subjective norms, which will be measured at baseline and at one and six months after the intervention. Discussion: This study protocol presents the study design of a two-arm parallel-group randomized controlled trial to evaluate the effectiveness of the WDYD web-based brief alcohol intervention. We hypothesized a reduction in mean weekly alcohol consumption and in the frequency of binge drinking in the experimental condition, resulting from the web-based brief alcohol intervention, compared to the control condition.7 p

Drinking Refusal Self-Efficacy and Intended Alcohol Consumption During a Mass-Attended Youth Event

© 2017 Taylor & Francis Group, LLC Background: Mass-attended youth events represent a substantial public health challenge due to high levels of alcohol consumption and corresponding high rates of alcohol-related harm. Although previous research has documented the protective effect of high drinking refusal self-efficacy (DRSE) on alcohol consumption in general, there is a lack of research examining the role of DRSE in reducing consumption during mass-attended youth events and the factors associated with DRSE in these contexts. Objectives: This study aimed to identify potentially modifiable factors that influence DRSE and drinking intentions to inform interventions designed to reduce alcohol-related harm during mass-attended events. Methods: Australian secondary school students (n = 586; 70% female) in their final two years of high school completed an online survey assessing their alcohol consumption intentions for Schoolies, their perceived degree of DRSE, and other individual and environmental factors. Path analysis was used to assess a mediational model examining factors associated with DRSE and alcohol consumption intentions. Results: DRSE was found to be significantly associated with intended alcohol consumption during Schoolies. Specifically, leavers who believed they would not be able to refuse others' offers of alcoholic drinks reported significantly greater alcohol consumption intentions. Results also revealed that DRSE was enhanced in those respondents who believed there would be a variety of non-drinking activities and non-alcoholic beverages available to them during Schoolies. Conclusion: Results suggest the need to increase leavers' confidence in their ability to refuse unwanted alcoholic beverages and highlight the importance of providing celebration options that do not involve alcohol consumption