An integrated approach to studying the relationship between anadromy and iteroparity in Atlantic salmon (Salmo salar)

Atlantic salmon is an anadromous species capable of spawning more than once during its lifecycle, being iteroparous. Increasing conservation concern has led to increased attention being paid to the potential short-term mitigating effects that iteroparous individuals may serve to populations suffering from low juvenile to adult recruitment. Despite the current research focus on repeat spawning Atlantic salmon, little is still known about how the iteroparous life cycle affects intrapopulation variation in marine movements and potential implications for population dynamics. The current thesis applied an integrated approach to studying the relationship between anadromy and iteroparity in Atlantic salmon from Newfoundland (Canada). Acoustic telemetry, scale pattern, stable isotope, fatty acid and mark-recapture analyses were included as analytical methods to investigate aspects of the relationship between iteroparity and anadromy and its importance in shaping the marine migratory patterns of Atlantic salmon. Using acoustic telemetry applied to 78 kelts and 90 smolts from two populations, I found that life stage influenced migratory movements and behaviour during the nearshore marine phase. Specifically, migratory movements were characterized by faster, more directed and less nocturnal movements by kelts as compared to smolts. These contrasts, however, varied by population, and the source of this variation was suggested to include responses to temporal and physical contrasts in the biotic and abiotic environment that shape the constraints imposed by trade-offs such as those between the need to reduce predation risk and increase growth and mass-gain. Using fatty acid (FA) and stable isotope analyses applied to 72 returning adults, I also found that life stage, as well as spawning history, influence migratory movements and dietary patterns during the at-sea phase. Specifically, significant differences in FA composition and ratios of δ¹⁵N in dorsal muscle tissue were identified, which supported the hypothesized divergent use of dietary sources among the different spawning history groups. Significant differences in FA composition, as well as lipid density, were also found among the different spawning histories in 69 post-spawned Atlantic salmon sampled as they emigrated from the river. Furthermore, patterns in lipid density were consistent with patterns in kelt return rates to consecutive repeat spawning. Consecutively spawned kelts and females had significantly higher lipid density than first-time spawned kelts and males, and consecutively spawned kelts and females experienced higher return rates compared to first-time spawned kelts and males. It was suggested that these spawning history related contrasts in energetic and nutritional state in post-spawned Atlantic salmon may be a carry-over effect of contrasts in the non-breeding area as affected by spawning-history dependent migration strategies, or alternatively, may represent an adaptive response to increased survival and recovery potential with age

Measuring renewables’ impact on biosphere integrity: A review

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Do Parental Education-Related Inequality Matter in Child and Adolescent Utilization of Mental Health Services: Results From a Norwegian Register Linkage Study

Equitable access to health care point to equal access to care for those with equal needs, but pro-rich and pro-educated inequities have been documented in specialized mental health care utilization. This study aimed to investigate equity in Norwegian adolescents’ use of child and adolescent mental health services (CAMHS) with regards to parental education levels, using a survey of 10 257 Norwegian 16- to 19-year-olds subsequently linked to CAMHS data from the Norwegian Patient Registry (n = 970 had been in contact with CAMHS). Analyses using concentration indices (C) suggested adolescents with parents with lower education levels had more mental health problems (ie, larger need; C = −0.032, P < .001) and were more in contact with CAMHS (C = −0.025, P < .001). Regression analysis suggested that CAMHS contact, and number of unique admissions was largely distributed according to need, but participants whose parents had basic education levels were in contact with CAMHS for slightly longer than predicted from their self-reported mental health problems, age, and sex. Results from this study suggested that contact with CAMHS was largely equitable and mostly influenced by need. There was little evidence of parental education-related inequity in access to, and use of, specialized mental health services.publishedVersio

Parental separation and school dropout in adolescence

Aims: To document the association between parental separation and school dropout in adolescence and to examine the factors that may potentially account for this association. Methods: Data stem from the large youth@hordaland study that was linked to the Norwegian National Educational Database to obtain objective measures of educational outcomes and disposable income (N = 8323). Logistic regression analysis was used to investigate the association between parental separation and school dropout. A Fairlie post-regression decomposition was used to examine the influence of parental education, household income, health complaints, family cohesion, and peer problems in explaining the association between parental separation and school dropout. Results: Parental separation was associated with a higher odds ratio (OR) of school dropout in crude and adjusted (adjusted odds ratio (AOR)) analyses (OR=2.16, 95% confidence interval (CI) =1.90–2.45; AOR = 1.72, 95% CI = 1.50–2.00). About 31% of the higher odds of school dropout among adolescents with separated parents was explained by the covariates. The decomposition analysis suggested that parental education (43%) and disposable income (20%) accounted for most of the explained differences in school dropout. Conclusions: Adolescents with separated parents are at higher risk for not completing secondary education. Parental education and disposable income accounted for most of the explained differences in school dropout between the groups. Still, the majority of the difference in school dropout remained unaccounted for, indicating that the link between parental separation and school dropout is complex and likely influenced by multiple factors.publishedVersio

""Frisk, men likevel ikke som før-"" : slagrammedes erfaringer etter hjerneslag og trombolytisk behandling

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Health-related quality of life of children from low-income families : the New Patterns study

Acknowledgements The authors thank the participating families, municipalities, and family coordinators for their commitment to the New Patterns project. Funding The study was supported by the Norwegian Research Council (Grant # 295686).Peer reviewedPublisher PD

Sleep and dropout from upper secondary school: A register-linked study

Objective The present study investigates the association between sleep in late adolescence and completion of upper secondary school. Methods The data are drawn from the youth@hordaland study, a large population-based study conducted in 2012, linked with official educational data in Norway (N = 8838). Results High school dropout was more prevalent among adolescents who had insomnia (20.6%) compared to those without insomnia (14.3%; adjusted risk ratios = 1.50; 95% confidence intervals: [2.19-2.92]). There was also a higher rate of school dropout among those who had symptoms of delayed sleep-wake phase (21%) compared to those without delayed sleep-wake phase (14.3%); adjusted risk ratios = 1.43, 95% confidence intervals: (1.28-1.59). School noncompleters were also characterized by reporting 44 minutes shorter sleep duration, longer sleep onset latency, and wake after sleep onset (both approx. 15 minutes) compared to school completers. Conclusion The importance of sleep for high school dropout rates highlights the importance of including sleep as a risk indicator and a possible target for preventive interventions in late adolescence.publishedVersio

Divorce and adolescent academic achievement: Heterogeneity in the associations by parental education

Background The link between parental divorce and adolescents’ academic achievement may depend on parental educational levels. However, findings have been inconsistent regarding whether the negative associations between parental divorce and adolescents’ academic outcomes are greater or smaller in highly educated families. The present study aimed to investigate the possible heterogeneity in the associations between divorce and adolescents’ academic achievement by parental educational levels, within the context of the elaborate Norwegian welfare state. Methods The population-based cross-sectional youth@hordaland study of adolescents aged 16–19 years conducted in Norway in 2012, provided information about parental divorce and was linked to national administrative registries (N = 9,166) to obtain high-quality, objective data on the adolescents’ grade point average (GPA), and their parents’ educational qualifications and income. Results The negative association between parental divorce and GPA was stronger among adolescents with educated or highly educated parents compared to adolescents with less educated parents. This heterogeneity was driven by maternal educational qualifications, whereby divorce was more strongly and negatively associated with GPA among adolescents with educated mothers compared to those with less educated mothers, independent of paternal educational levels and income measures. Conclusions Among adolescents whose parents have low educational qualifications, parental divorce is not associated with their academic achievement. Educated divorced mothers appear less likely to transfer their educational advantages onto their children than nondivorced equally educated mothers, perhaps due to a “double-burden” regarding work pressure and child-rearing responsibilities. There is a need for future studies to detail the mechanisms underlying this finding.publishedVersio

Self-reported and parent-reported mental health in children from low income families in Agder, Norway : results from baseline measurements of New Patterns project participants

Acknowledgments We would like to thank master’s students Vilde Johanna Solheim Lie, Hedda Andrea Struksnæs Sørdal and HAO whose theses in clinical psychology at the University of Bergen functioned as a first draft to this article. We would like to thank the participants and acknowledge the New Patterns project family coordinators who conducted the mapping and supported the participants over time. Funding The work was partly funded by a grant from the Research Council of Norway (number 295686).Peer reviewedPublisher PD