The influence of temperature on the development of Baltic Sea sprat (Sprattus sprattus) eggs and yolk sac larvae

In spring 2004 and 2005 we performed two sets of experiments with Baltic sprat (Sprattus sprattus balticus Schneider) eggs and larvae from the Bornholm Basin simulating ten different temperature scenarios. The goal of the present study was to analyse and parameterise temperature effects on the duration of developmental stages, on the timing of important ontogenetic transitions, growth during the yolk sac phase as well as on the survival success of eggs and early larval stages. Egg development and hatching showed exponential temperature dependence. No hatching was observed above 14.7°C and hatching success was significantly reduced below 3.4°C. Time to eye pigmentation, as a proxy for mouth gape opening, decreased with increasing temperatures from 17 days post hatch at 3.4°C to 7 days at 13°C whereas the larval yolk sac phase was shortened from 20 to 10 days at 3.8 and 10°C respectively. Maximum survival duration of non-fed larvae was 25 days at 6.8°C. Comparing the experimental results of Baltic sprat with existing information on sprat from the English Channel and North Sea differences were detected in egg development rate, thermal adaptation and in yolk sac depletion rate (YSDR). Sprat eggs from the English Channel showed significantly faster development and the potential to develop at temperatures higher than 14.7°C. North Sea sprat larvae were found to have a lower YSDR compared to larvae from the Baltic Sea. In light of the predictions for global warming, Baltic sprat stocks could experience improved conditions for egg development and surviva

Sex differences in risk-based decision making in adolescents with conduct disorder

Altered decision making processes and excessive risk-seeking behaviours are key features of conduct disorder (CD). Previous studies have provided compelling evidence of abnormally increased preference for risky options, higher sensitivity to rewards, as well as blunted responsiveness to aversive outcomes in adolescents with CD. However, most studies published to date have focused on males only; thus, it is not known whether females with CD show similar alterations in decision making. The current study investigated potential sex differences in decision making and risk-seeking behaviours in adolescents with CD. Forty-nine adolescents with CD (23 females) and 51 control subjects (27 females), aged 11-18 years, performed a computerised task assessing decision making under risk—the Risky Choice Task. Participants made a series of decisions between two gamble options that varied in terms of their expected values and probability of gains and losses. This enabled the participants’ risk preferences to be determined. Taking the sample as a whole, adolescents with CD exhibited increased risk-seeking behaviours compared to healthy controls. However, we found a trend towards a sex-by-group interaction, suggesting that these effects may vary by sex. Follow-up analyses showed that males with CD made significantly more risky choices than their typically developing counterparts, while females with CD did not differ from typically developing females in their risk-seeking behaviours. Our results provide preliminary evidence that sex may moderate the relationship between CD and alterations in risk attitudes and reward processing, indicating that there may be sex differences in the developmental pathways and neuropsychological deficits that lead to CD

Influence of mental health and alcohol or other drug use risk on adolescent reported care received in primary care settings

Abstract Background To describe patterns of alcohol and other drug (AOD) use risk and adolescent reported primary care (PC) screening and intervention, and examine associations of AOD risk and mental health with reported care received. Methods We analyzed data from cross-sectional surveys collected from April 3, 2013 to November 24, 2015 from 1279 diverse adolescents ages 12–18 who reported visiting a doctor at least once in the past year. Key measures were AOD risk using the Personal Experience Screening Questionnaire; mental health using the 5-item Mental Health Inventory; binary measures of adolescent-reported screening and intervention. Results Half (49.2%) of the adolescents reported past year AOD use. Of the 769 (60.1%) of adolescents that reported being asked by a medical provider in PC about AOD use, only 37.2% reported receiving screening/intervention. The odds of reported screening/intervention were significantly higher for adolescents with higher AOD risk and lower mental health scores. Conclusions Adolescents at risk for AOD use and poor mental health are most likely to benefit from brief intervention. These findings suggest that strategies are needed to facilitate medical providers identification of need for counseling of both AOD and mental health care for at risk youth. Trials registration clinicaltrials.gov , Identifier: NCT01797835, March 2013