An integrated simulation model to evaluate national policies for the abatement of agricultural nutrients in the Baltic Sea

This study introduces a prototype model for evaluating policies to abate agricultural nutrients in the Baltic Sea from a Finnish national point of view. The stochastic simulation model integrates nutrient dynamics of nitrogen and phosphorus in the sea basins adjoining the Finnish coast, nutrient loads from land and other sources, benefits from nutrient abatement (in the form of recreation and other ecosystem services) and the costs of agricultural abatement activities. The aim of this study is to present the overall structure of the model and to demonstrate its potential using preliminary parameters. The model is made flexible for further improvements in all of its ecological and economic components. Results of a sensitivity analysis suggest that investments in reducing the nutrient runoff from arable land in Finland would become profitable only if Finland’s neighbors in the northern Baltic committed themselves to similar reductions. Environmental investments for improving water quality yield the highest returns for the Bothnian Bay and the Gulf of Finland, and smaller returns for the Bothnian Sea. In the Bothnian Bay, the abatement activities become profitable because the riverine loads from Finland represent a high proportion of the total nutrient loads. In the Gulf of Finland, this proportion is low, but the size of the coastal population benefiting from improved water quality is high.ecosystem services, nutrient abatement, Monte Carlo simulation, recreation, valuation, Environmental Economics and Policy, Research Methods/ Statistical Methods,

Leisure-time physical inactivity and association with body mass index : a Finnish Twin Study with a 35-year follow-up

Background: We investigated the stability and change of leisure-time physical inactivity in adult men and women during a 35-year follow-up. We also analysed the impact of long-term physical inactivity on the development of body mass index (BMI). Methods: In this population-based cohort study, 5254 Finnish twin individuals (59% women) participated in four surveys in 1975, 1981, 1990 and 2011. Mean age at baseline was 23.9 years. Individual long-term leisure-time physical activity (LTPA) was categorized into seven classes varying from 'persistently inactive' to 'persistently active'. We used the multivariate multilevel mixed-effects linear regression model and paired-sample t-test in the analyses. Co-twin control design was used for examining within-pair associations. Results: Of men 11%, and of women 8%, were persistently inactive. Among both sexes, the mean BMI slope trajectories were steeper among the persistently inactive and those who became inactive than among those who were persistently active. Overall, the inactive participants gained 1.4 kg/m(2) [95% confidence interval (CI) 1.2 to 1.7] more in weight than did the active participants from 1975 to 2011. Among twin pairs discordant for LTPA, the corresponding difference was 1.4 kg/m(2) (95% CI 0.83 to 2.0) in dizygotic pairs and 0.68 kg/m(2) (95% CI 0.05 to1.3) in monozygotic pairs. Conclusions: Over a 35-year time span from young adulthood, persistently inactive participants and those who had become inactive had greater weight increases than those who were persistently active. This association was also found in twin-pair analyses, although attenuated in monozygotic pairs. This may support the importance of LTPA in weight management, although further causal inference is required.Peer reviewe

Long-term leisure-time physical activity and other health habits as predictors of objectively monitored late-life physical activity - A 40-year twin study

Moderate-to-vigorous physical activity (MVPA) in old age is an important indicator of good health and functional capacity enabling independent living. In our prospective twin cohort study with 616 individuals we investigated whether long-term physical activity assessed three times, in 1975, 1982 and 1990 (mean age 48 years in 1990), and other self-reported health habits predict objectively measured MVPA measured with a hip-worn triaxial accelerometer (at least 10 hours per day for at least 4 days) 25 years later (mean age of 73 years). Low leisure-time physical activity at younger age, higher relative weight, smoking, low socioeconomic status, and health problems predicted low MVPA in old age in individual-based analyses (altogether explaining 20.3% of the variation in MVPA). However, quantitative trait modeling indicated that shared genetic factors explained 82% of the correlation between baseline and follow-up physical activity. Pairwise analyses within monozygotic twin pairs showed that only baseline smoking was a statistically significant predictor of later-life MVPA. The results imply that younger-age physical activity is associated with later-life MVPA, but shared genetic factors underlies this association. Of the other predictors mid-life smoking predicted less physical activity at older age independent of genetic factors.Peer reviewe

Predictive Association of Smoking with Depressive Symptoms : a Longitudinal Study of Adolescent Twins

Longitudinal, genetically informative studies of the association between cigarette smoking and depressive symptoms among adolescents are limited. We examined the longitudinal association of cigarette smoking with subsequent depressive symptoms during adolescence in a Finnish twin cohort. We used prospective data from the population-based FinnTwin12 study (maximum N = 4152 individuals, 1910 twin pairs). Current smoking status and a number of lifetime cigarettes smoked were assessed at the age of 14 and depressive symptoms at the age of 17. Negative binomial regression was conducted to model the association between smoking behavior and subsequent depressive symptoms among individuals, and within-pair analyses were conducted to control for unmeasured familial confounding. Analyses were adjusted for age, sex, school grades, drinking alcohol to intoxication, health status, family structure, parental education, and smoking, as well as for pre-existing depressiveness. The results of the individual-level analyses showed that cigarette smoking at the age of 14 predicted depressive symptoms at the age of 17. Compared to never smokers, those who had smoked over 50 cigarettes (incidence rate ratio, IRR = 1.43, 95% CI 1.28-1.60) and regular smokers (IRR = 1.46, 95% CI 1.32-1.62) had higher depression scores. The associations were attenuated when adjusted for measured covariates and further reduced in within-pair analyses. In the within-pair results, the estimates were lower within monozygotic (MZ) pairs compared to dizygotic (DZ) pairs, suggesting that shared genetic factors contribute to the associations observed in individual-based analyses. Thus, we conclude that cigarette smoking is associated with subsequent depressive symptoms during adolescence, but the association is not independent of measured confounding factors and shared genetic influences.Peer reviewe

Genome-wide time-to-event analysis on smoking progression stages in a family-based study

Background: Various pivotal stages in smoking behavior can be identified, including initiation, conversion from experimenting to established use, development of tolerance, and cessation. Previous studies have shown high heritability for age of smoking initiation and cessation; however, time-to-event genome-wide association studies aiming to identify underpinning genes that accelerate or delay these transitions are missing to date. Methods: We investigated which single nucleotide polymorphisms (SNPs) across the whole genome contribute to the hazard ratio of transition between different stages of smoking behavior by performing time-to-event analyses within a large Finnish twin family cohort (N = 1962), and further conducted mediation analyses of plausible intermediate traits for significant SNPs. Results: Genome-wide significant signals were detected for three of the four transitions: (1) for smoking cessation on 10p14 (P = 4.47e-08 for rs72779075 flanked by RP11-575N15 and GATA3), (2) for tolerance on 11p13 (P = 1.29e-08 for rs11031684 in RP1-65P5.1), mediated by smoking quantity, and on 9q34.12 (P = 3.81e-08 for rs2304808 in FUBP3), independent of smoking quantity, and (3) for smoking initiation on 19q13.33 (P = 3.37e-08 for rs73050610 flanked by TRPM4 and SLC6A16) in analysis adjusted for first time sensations. Although our top SNPs did not replicate, another SNP in the TRPM4-SLC6A16 gene region showed statistically significant association after region-based multiple testing correction in an independent Australian twin family sample. Conclusion: Our results suggest that the functional effect of the TRPM4-SLC6A16 gene region deserves further investigation, and that complex neurotransmitter networks including dopamine and glutamate may play a critical role in smoking initiation. Moreover, comparison of these results implies that genetic contributions to the complex smoking behavioral phenotypes vary among the transitions.Peer reviewe

Association between birthweight and later body mass index : an individual-based pooled analysis of 27 twin cohorts participating in the CODATwins project

Background: There is evidence that birthweight is positively associated with body mass index (BMI) in later life, but it remains unclear whether this is explained by genetic factors or the intrauterine environment. We analysed the association between birthweight and BMI from infancy to adulthood within twin pairs, which provides insights into the role of genetic and environmental individual-specific factors. Methods: This study is based on the data from 27 twin cohorts in 17 countries. The pooled data included 78 642 twin individuals (20 635 monozygotic and 18 686 same-sex dizygotic twin pairs) with information on birthweight and a total of 214 930 BMI measurements at ages ranging from 1 to 49 years. The association between birthweight and BMI was analysed at both the individual and within-pair levels using linear regression analyses. Results: At the individual level, a 1-kg increase in birthweight was linearly associated with up to 0.9 kg/m(2) higher BMI (P <0.001). Within twin pairs, regression coefficients were generally greater (up to 1.2 kg/m(2) per kg birthweight, P <0.001) than those from the individual-level analyses. Intra-pair associations between birthweight and later BMI were similar in both zygosity groups and sexes and were lower in adulthood. Conclusions: These findings indicate that environmental factors unique to each individual have an important role in the positive association between birthweight and later BMI, at least until young adulthood.Peer reviewe

Twin's Birth-Order Differences in Height and Body Mass Index From Birth to Old Age : A Pooled Study of 26 Twin Cohorts Participating in the CODATwins Project

We analyzed birth order differences in means and variances of height and body mass index (BMI) in monozygotic (MZ) and dizygotic (DZ) twins from infancy to old age. The data were derived from the international CODATwins database. The total number of height and BMI measures from 0.5 to 79.5 years of age was 397,466. As expected, first-born twins had greater birth weight than second-born twins. With respect to height, first-born twins were slightly taller than second-born twins in childhood. After adjusting the results for birth weight, the birth order differences decreased and were no longer statistically significant. First-born twins had greater BMI than the second-born twins over childhood and adolescence. After adjusting the results for birth weight, birth order was still associated with BMI until 12 years of age. No interaction effect between birth order and zygosity was found. Only limited evidence was found that birth order influenced variances of height or BMI. The results were similar among boys and girls and also in MZ and DZ twins. Overall, the differences in height and BMI between first-and second-born twins were modest even in early childhood, while adjustment for birth weight reduced the birth order differences but did not remove them for BMI.Peer reviewe

Noise sensitivity and multiple chemical sensitivity scales: Properties in a population based epidemiological study

Noise sensitivity is considered to be a self-perceived indicator of vulnerability to stressors in general and not noise alone. Multiple chemical sensitivity (MCS) has to some extent been accompanied by noise sensitivity, indicating a moderate correspondence between them. The aim of this study is to investigate if the Weinstein′s Noise Sensitivity Scale and Quick Environmental Exposure and Sensitivity Inventory′s (QEESI) Chemical Intolerance Subscale can differentiate noise sensitivity and MCS as different entities, and if there are overlaps in the characteristics of noise sensitivity and MCS. In 2002, 327 individuals (166 men, 161 women; age range 45 - 66 years) from the Finnish Twin Cohort answered a questionnaire on noise-related and MCS items. Somatic, psychological, and lifestyle factors were obtained through earlier questionnaires for the same individuals. Both confirmatory and exploratory factor analyses (CFA and EFA) of the questionnaire items on the Weinstein′s Noise Sensitivity Scale and QEESI′s Chemical Intolerance Subscale indicated the presence of three factors - Noise Sensitivity, Chemical Sensitivity, and Ability to Concentrate factors - arising from the forming of two factors from the items of the Weinstein′s scale. In the regression analyses, among all subjects, the Noise Sensitivity Factor was associated with neuroticism and smoking, and the Chemical Sensitivity Factor was associated with allergies and alcohol use. The study indicates that the Weinstein′s Noise Sensitivity Scale and QEESI′s Chemical Intolerance Subscale differentiate noise sensitivity and MCS as different entities