Individual Lifetime Research Articles

Mendelian Randomization.

Confounding and reverse causality have prevented us from drawing meaningful clinical interpretation even in well-powered observational studies. Confounding may be attributed to our inability to randomize the exposure variable in observational studies. Mendelian randomization (MR) is one approach to overcome confounding. It utilizes one or more genetic polymorphisms as a proxy for the exposure variable of interest. Polymorphisms are randomly distributed in a population, they are static throughout an individual's lifetime, and may thus help in inferring directionality in exposure-outcome associations. Genome-wide association studies (GWAS) or meta-analyses of GWAS are characterized by large sample sizes and the availability of many single nucleotide polymorphisms (SNPs), making GWAS-based MR an attractive approach. GWAS-based MR comes with specific challenges, including multiple causality. Despite shortcomings, it still remains one of the most powerful techniques for inferring causality.With MR still an evolving concept with complex statistical challenges, the literature is relatively scarce in terms of providing working examples incorporating real datasets. In this chapter, we provide a step-by-step guide for causal inference based on the principles of MR with a real dataset using both individual and summary data from unrelated individuals. We suggest best possible practices and give recommendations based on the current literature.

Health risk assessment of potable water containing small amount of tritium oxide

The problem of groundwater pollution with tritium in a vicinity of radiation-dangerous facilities in Obninsk is considered. The information on the specific activity of tritium in Obninsk water sources is provided. The formula for the calculation of the β-radiation absorbed dose from tritium ingestion is proposed, reflecting the biological behavior of tritium in a human body. To establish the extent of tritium effects on human, the health risk is assessed. It is shown that if the specific activity of tritium in drinking water amounts to 10 Bq/l, the risk of stochastic effects of radiation will not exceed the limit of the individual lifetime risk.

Exploration and sociability in a highly gregarious bird are repeatable across seasons and in the long term but are unrelated

Personality traits and behavioural syndromes are often assumed to relate to life history strategies and lifetime fitness variation and hence may be generally under selection. Key in this regard is the, often untested, assumption that individual differences in (correlated) behaviours are maintained across contexts and over an individual's lifetime. Here, we tested this assumption, using a population of 30 captive male starlings, Sturnus vulgaris, a highly gregarious avian species. We repeatedly assayed novel environment exploration and different aspects of sociability towards a female conspecific, across seasonal contexts (spring and autumn) and across a 2-year period, which represents a substantial portion of a starling's life span. We found that, regardless of plasticity at the population level, both exploration behaviour and sociability traits investigated were moderately repeatable across seasons and years, with no significant differences between repeatability estimates over different timescales. However, no evidence was found for significant between-individual correlations between the investigated traits, including different aspects of sociability. Taken together, our results provide empirical evidence that exploration and sociability are personality traits that are stable across seasons and in the long term but do not form behavioural syndromes. Given the recent evidence that personality traits are often heritable, the traits assessed in our study might have the potential to evolve independently under selection. This long-term consistency in exploration and sociability might have important implications for the social organization within complex social environments and influence a wide variety of ecologically relevant processes.

Air Pollution and Potential Health Risk in Ostrava Region - a Review.

The aim of this review was to collect all available data about air pollution in Ostrava, which is one of the most polluted area in central Europe and to make a concise assessment of health risks resulting from historical exposures of air pollutants since the beginning of the monitoring, i.e. since 1970 to the present time. All available information sources (the Czech Hydrometeorological Institute, the Institute of Public Health in Ostrava or publications) were used. To evaluate the exposures both short-term (hourly and daily) data and long term (yearly) data during 45 years were analysed. For health risk assessment the relationship between exposure and biological effects of pollutants published by the WHO and the US EPA were employed. During the studied period annual average concentrations of PM10 ranged from 25 to 96 µg/m3; PM2.5 from 24 to 45 µg/m3; SO2 from 3.4 to 101.5 µg/m3; NO2 from 17.76 to 51.17 µg/m3; benzene from 0.24 to 9.2 µg/m3; benzo[a]pyrene from 2.1 to 14 ng/m3; arsenic from 1.2 to 9.5 ng/m3. Since the turn of the 80s and 90s of the 20th century trend of air pollutant concentrations has been decreasing until the turn of millennium, when it stopped, and it has been constant until present time. However, presented results demonstrate that the citizens of Ostrava have been exposed to relatively high concentrations of pollutants in comparison to other similar cities. The most significant pollutants contributing to health risks are airborne dust (PM10, PM2.5), benzene and benzo[a]pyrene. The long-term average health risk of PM10 has increased in case of postneonatal infant mortality up to 30%; prevalence of bronchitis in children up to 61%; and incidence of chronic bronchitis in adults up to 89%. The long-term average health risk of PM2.5 increased for all-cause mortality in persons aged 30+ years up to 22%; cardiopulmonary related mortality up to 25%; and lung cancer related mortality up to 39%. The highest carcinogenic risk is observed in benzo[a]pyrene, when the range of individual lifetime carcinogenic risk is up to 1.25*10-3. This assessment is valid according to the strict carcinogenic risk by the WHO, while the maximum carcinogenic risk according the US EPA is 7.2*10-5. A significant reduction of the pollutants' concentrations in Ostrava in the nineties of the last century does not mean a required improvement of outdoor air quality to the desired level. Persisting episodes with a very strong short-term increase of the concentration of PM10 and PM2.5, as well as long-term load of these substances on the population is very high. Health risks from such burdens are likely to lead to a higher mortality and morbidity especially from specific diseases.

Personalized, Genomic-Based Care Could Mean a Paradigm Shift

Personalized, Genomic-Based Care Could Mean a Paradigm Shift

Nitrogen:phosphorous supply ratio and allometry in five alpine plant species.

In terrestrial ecosystems, atmospheric nitrogen (N) deposition has greatly increased N availability relative to other elements, particularly phosphorus (P). Alterations in the availability of N relative to P can affect plant growth rate and functional traits, as well as resource allocation to above‐ versus belowground biomass (M A and M B). Biomass allocation among individual plants is broadly size‐dependent, and this can often be described as an allometric relationship between M A and M B, as represented by the equation MA=αMBβ, or log M A = logα + βlog M B. Here, we investigated whether the scaling exponent or regression slope may be affected by the N:P supply ratio. We hypothesized that the regression slope between M A and M B should be steeper under a high N:P supply ratio due to P limitation, and shallower under a low N:P supply ratio due to N limitation. To test these hypotheses, we experimentally altered the levels of N, P, and the N:P supply ratio (from 1.7:1 to 135:1) provided to five alpine species representing two functional groups (grasses and composite forbs) under greenhouse conditions; we then measured the effects of these treatments on plant morphology and tissue content (SLA, leaf area, and leaf and root N/P concentrations) and on the scaling relationship between M A and M B. Unbalanced N:P supply ratios generally negatively affected plant biomass, leaf area, and tissue nutrient concentration in both grasses and composite forbs. High N:P ratios increased tissue N:P ratios in both functional groups, but more in the two composite forbs than in the grasses. The positive regression slopes between log M A and log M B exhibited by plants raised under a N:P supply ratio of 135:1 were significantly steeper than those observed under the N:P ratio of 1.7:1 and 15:1. Synthesis: Plant biomass allocation is highly plastic in response to variation in the N:P supply ratio. Studies of resource allocation of individual plants should focus on the effects of nutrient ratios as well as the availability of individual elements. The two forb species were more sensitive than grasses to unbalanced N:P supplies. To evaluate the adaptive significance of this plasticity, the effects of unbalanced N:P supply ratio on individual lifetime fitness must be measured.

The role and impact of estrogens and xenoestrogen on the development of cervical cancer.

Throughout an individual's lifetime, the human body is exposed to many different chemical compounds, including xenoestrogens (XEs) that can be found in the environment, food, air, cosmetics and other substances, which have a positive or negative impact on their health and lifestyle. Whereas high-risk human papillomavirus (HR-HPV) is necessary but not sufficient for full malignant cervical cell transformation, other compounds such as estrogens and XEs may be risk factors for cervical cancer (CC) development. The causes and effects of some diseases such as cancer, cardiovascular, metabolic or immune system disorders are partly due to signaling pathways in response to estrogens. XEs are a vast group of natural and synthetic compounds, behaving like estrogens, that have been studied over the recent years and which may interact with estrogen receptors. The major problem with XEs is the difficulty in studying the mechanism of such complex substances as well as investigating the influences of some of the compounds (dose-dependent) over time. The impact of XEs on CC is variable, with no direct comparison between in vitro studies and in vivo XEs action.

Diagnosis: Overload

Diagnosis: Overload

Socio-economics, food habits and the prevalence of childhood obesity in Spain.

In 2012, the prevalence of obesity and overweight statuses among children in Spain was 9% and 26%, respectively. Concerns about childhood obesity have increased over the past few years, as obesity developed during childhood can persist throughout an individual's lifetime (cohort effect). This study aims to develop a better understanding of the factors influencing the prevalence of obesity in Spain. Microdata from the 2012 National Health Survey are used, and the methodological framework is based on the estimation of a sample selection model. Results suggest that the prevalence of obesity increases among children who live in households of a lower socio-economic status and households in which parents are obese. Lower levels of childhood physical activity are positively related to the probability of being obese. Finally, there exists a positive relationship between children's body mass index and an inappropriate intake of fresh fruits, fish, pasta and rice, legumes, sweets and soft drinks. The methodological framework used in this study is flexible enough to be used in traditional longitudinal studies. Children's and households' lifestyles play a pivotal role in the prevalence of obesity. Policies should be oriented toward changing lifestyles, which would require more multidisciplinary research in the future to reduce childhood obesity.

Inequality of Opportunity for Healthy Aging in Europe

This study quantifies the inequality of opportunity (IOp) for healthy aging in Europe. Unlike earlier studies, an objective health indicator, grip strength, is used as an outcome. Using the longitudinal data from the Survey of Health, Aging and Retirement in Europe (Wave 1-5), I introduce a general model where explanatory variables portray individual lifetime trajectory. All predictors are disentangled into illegitimate and legitimate components. The Hausman-Taylor (1981) estimator is employed to deal with the presence of unobserved heterogeneity and endogeneity of time-variant lifestyle. Both upper and lower bounds of IOp are considered by incorporating different sets of illegitimate factors under six scenarios. Parallel results based on self-reported health are provided. We find that IOp in a subjective measure is less sensitive to age, but more to unobserved factors. Finally, the magnitude of IOp is compared between men and women as well as across ten states Denmark, Sweden, Switzerland, Austria, Germany, France, the Netherlands, Belgium, Spain and Italy. Overall, the results are sensitive to the choice in health indicator.

Geographic and Individual Differences in Healthcare Access for U.S. Transgender Adults: A Multilevel Analysis.

To identify geographic and individual-level factors associated with healthcare access among transgender people in the United States. Multilevel analyses were conducted to investigate lifetime healthcare refusal using national data from 5831 U.S. transgender adults. Hierarchical generalized linear models examined associations between individual (age, gender, race, income, insurance, and healthcare avoidance) and state-level factors (percent voting Republican, percent same-sex couple households, income inequality, and transgender protective laws) and lifetime refusal of care. Results show that individual-level factors (being older; trans feminine; Native American, multiracial, or other racial/ethnic minority; having low income; and avoiding care due to discrimination) are positively associated with care refusal (all P-values <0.05). Adjusting for individual-level factors, variation was observed across U.S. states, with a greater proportion of states in the Southern and Western United States with transgender residents at increased odds of experiencing care refusal, relative to other regions of the United States. When adjusting for state-level factors, the percentage of the state population voting Republican was positively associated with care refusal among the transgender adults sampled (P < 0.01). Transgender adults surveyed reported differential access to healthcare by geographic region. Identifying geographic and individual-level factors associated with healthcare barriers allows for the development of targeted educational and policy interventions to improve healthcare access for transgender people most in need of services.

Analysis of Dynamic Interactions between Different Drivetrain Components with a Detailed Wind Turbine Model

The presented work describes a detailed analysis of the dynamic interactions among mechanical and electrical drivetrain components of a modern wind turbine under the influence of parameter variations, different control mechanisms and transient excitations. For this study, a detailed model of a 2MW wind turbine with a gearbox, a permanent magnet synchronous generator and a full power converter has been developed which considers all relevant characteristics of the mechanical and electrical subsystems. This model includes an accurate representation of the aerodynamics and the mechanical properties of the rotor and the complete mechanical drivetrain. Furthermore, a detailed electrical modelling of the generator, the full scale power converter with discrete switching devices, its filters, the transformer and the grid as well as the control structure is considered. The analysis shows that, considering control measures based on active torsional damping, interactions between mechanical and electrical subsystems can significantly affect the loads and thus the individual lifetime of the components.

Non-Parametric Integral Estimation Using Data Clustering in Stochastic Dynamic Programming: An Introduction Using Lifetime Financial Modelling

This paper considers an alternative way of structuring stochastic variables in a dynamic programming framework where the model structure dictates that numerical methods of solution are necessary. Rather than estimating integrals within a Bellman equation using quadrature nodes, we use nodes directly from underlying data. An example of the application of this approach is presented using individual lifetime financial modelling. The results show significant benefits to the data-driven approach compared to quadrature and Quasi-Monte Carlo approaches, which hold for both a single stochastic variable and multiple stochastic variables.

Dynamic Range Size Analysis of Territorial Animals: An Optimality Approach.

Home range sizes of territorial animals are often observed to vary periodically in response to seasonal changes in foraging opportunities. Here we develop the first mechanistic model focused on the temporal dynamics of home range expansion and contraction in territorial animals. We demonstrate how simple movement principles can lead to a rich suite of range size dynamics, by balancing foraging activity with defensive requirements and incorporating optimal behavioral rules into mechanistic home range analysis. Our heuristic model predicts three general temporal patterns that have been observed in empirical studies across multiple taxa. First, a positive correlation between age and territory quality promotes shrinking home ranges over an individual's lifetime, with maximal range size variability shortly before the adult stage. Second, poor sensory information, low population density, and large resource heterogeneity may all independently facilitate range size instability. Finally, aggregation behavior toward forage-rich areas helps produce divergent home range responses between individuals from different age classes. This model has broad applications for addressing important unknowns in animal space use, with potential applications also in conservation and health management strategies.

Levels, sources, and health risk assessment of polycyclic aromatic hydrocarbons in Brno, Czech Republic: a 5-year study.

This work aimed to determine the seasonal variations of polycyclic aromatic hydrocarbons (PAHs) in airborne PM10 at two background sites (Masná-MS, Líšeň-LN) in Brno over a 5-year period (2009-2013). Samples were collected on quartz filters using a low-volume sampler by continual filtration. Concentrations of PAHs in collected PM10 samples were determined using a gas chromatography with a mass spectrometer as a detector. A different number of PAHs were determined to be at each site, i.e., 11 PAHs at the MS site and six PAHs at the LN site, and similarities between them were identified using non-parametric analysis of variance. Potential sources were identified using principal component analysis (PCA) and PAHs diagnostic ratios. The work also focused on health risk assessment. This was estimated using toxic equivalent factors to calculate individual lifetime cancer risk, which quantifies risk of exposure to PAHs for specific age groups. The average 11-PAH concentrations in M|S site annually ranged from 19.28±19.02ngm-3 (2011) to 40.37±21.35ngm-3 (2013). With regard to the LN site, the average six-PAH concentrations annually ranged from 3.64±3.87ngm-3 (2009) and 5.27±6.19ngm-3 (2012). PCA and diagnostic ratios indicate the main sources to be traffic emissions and coal combustion. Health risk assessment showed carcinogenic risk under limit value in all cases.

The prevalence, age distribution and comorbidity of personality disorders in Australian women.

We aimed to describe the prevalence and age distribution of personality disorders and their comorbidity with other psychiatric disorders in an age-stratified sample of Australian women aged ⩾25 years. Individual personality disorders (paranoid, schizoid, schizotypal, histrionic, narcissistic, borderline, antisocial, avoidant, dependent, obsessive-compulsive), lifetime mood, anxiety, eating and substance misuse disorders were diagnosed utilising validated semi-structured clinical interviews (Structured Clinical Interview for DSM-IV-TR Axis I Disorders, Research Version, Non-patient Edition and Structured Clinical Interview for DSM-IV Axis II Personality Disorders). The prevalence of personality disorders and Clusters were determined from the study population ( n = 768), and standardised to the Australian population using the 2011 Australian Bureau of Statistics census data. Prevalence by age and the association with mood, anxiety, eating and substance misuse disorders was also examined. The overall prevalence of personality disorders in women was 21.8% (95% confidence interval [CI]: 18.7, 24.9). Cluster C personality disorders (17.5%, 95% CI: 16.0, 18.9) were more common than Cluster A (5.3%, 95% CI: 3.5, 7.0) and Cluster B personality disorders (3.2%, 95% CI: 1.8, 4.6). Of the individual personality disorders, obsessive-compulsive (10.3%, 95% CI: 8.0, 12.6), avoidant (9.3%, 95% CI: 7.1, 11.5), paranoid (3.9%, 95% CI: 3.1, 4.7) and borderline (2.7%, 95% CI: 1.4, 4.0) were among the most prevalent. The prevalence of other personality disorders was low (⩽1.7%). Being younger (25-34 years) was predictive of having any personality disorder (odds ratio: 2.36, 95% CI: 1.18, 4.74), as was being middle-aged (odds ratio: 2.41, 95% CI: 1.23, 4.72). Among the strongest predictors of having any personality disorder was having a lifetime history of psychiatric disorders (odds ratio: 4.29, 95% CI: 2.90, 6.33). Mood and anxiety disorders were the most common comorbid lifetime psychiatric disorders. Approximately one in five women was identified with a personality disorder, emphasising that personality disorders are relatively common in the population. A more thorough understanding of the distribution of personality disorders and psychiatric comorbidity in the general population is crucial to assist allocation of health care resources to individuals living with these disorders.

The contemporary face of gender differences and similarities in depression throughout adolescence: Development and chronicity

BackgroundWe probe the adolescent gender difference in depression, asking two critical questions. First, most longitudinal studies of gender differences in adolescent depression date from the 1980s and 1990s, raising the need for a body of evidence on whether the developmental pattern is similar or different today. Second, despite the importance of chronicity to depression, we do not know whether there is a gender difference in the chronicity burden of the disorder. MethodsIn a contemporary longitudinal sample of U.S. adolescents, depression symptoms were assessed at ages 11, 13, 15, and 18, and depression diagnoses were assessed at age 20. To capture the chronicity burden of clinical depression, we assessed for every depressive episode in an individual's lifetime and summed the total number of days spent in episode. ResultsA gender difference emerged at age 13 for depression symptoms and at ages 13–14 for diagnoses. These findings are similar to those in the 1980s and 1990s despite many social changes that have occurred. However, the magnitude of the gender difference in symptoms at ages 13 and 15 may be larger than those documented previously. Latent growth curve modeling of depression symptoms indicated that girls’ symptoms accelerated early in adolescence whereas boys’ symptoms accelerated later. Although more girls (24%) than boys (15%) experienced major depression or dysthymia by age 20, the chronicity burden among those with depression showed gender similarities (median=2.6% days depressed for boys and 2.4% for girls). LimitationsDepression diagnoses were assessed retrospectively; however, symptom data were assessed prospectively, and symptom and diagnostic data converged. The sample was also predominantly White, limiting generalizability. ConclusionsIn a contemporary adolescent sample we observed gender differences in depression symptoms and diagnoses beginning at age 13. We documented distinct developmental trajectories of depression for adolescent girls and boys, suggesting different developmental windows for depression prevention programs. We also discovered a gender similarity in the chronicity burden of clinical depression.

Veritas filia temporis: The origins of the idea of scientific progress

ABSTRACTThe article provides insight into the epistemological and anthropological aspect of the origination of the idea of scientific progress. It focuses on the relationship between individual's limited lifetime and the immensity of nature. The basic assumption is that the idea of scientific progress offers a solution of the epistemological problem stemming from the finding that there is no (teleological) coincidence between human cognitive abilities and the extent of nature. In order to facilitate the understanding of the origin of the idea of scientific progress, I propose distinction between the descriptive and prescriptive concepts of progress. While the descriptive notion of progress expresses the cumulative character of scientific knowledge and the superiority of the present over preceding generations, the prescriptive concept pertains to progressivist epistemology directing scientific research at the future development of knowledge. This article claims that the prevalent concept in Antiquity was the descriptive concept of scientific progress. The prescriptive notion had developed only in ancient astronomy. Early modern science was faced with similar issues as ancient astronomy – mainly the empirical finding related to the inexhaustible character of nature. Consequently to the introduction of the idea of progress, the progress of sciences became a purpose in itself – hence becoming infinite.

Nest-site Choice and Nest Construction in Non-avian Reptiles: Evolutionary Significance and Ecological Implications

In oviparous animals, nest-site choice is both a critical determinant of an individual's lifetime fitness, and an important demographic parameter of populations. At the individual level, the location and characteristics of a nest site impact survival of both the nesting female and the nestling or hatchling stage, and can also influence offspring phenotype and the survival of emerging juveniles. At the population level, survival rates of females and offspring, and phenotypes affected by incubation conditions, affect population trends. Reptiles differ from birds in several key life-history traits associated with nesting behaviour in that they have long incubation periods, bury eggs within a substrate, and have minimal parental care. However, studies in reptile systems have also demonstrated several evolutionary drivers of nest-site choice that are also likely to be important in avian systems. These include the role of incubation conditions in affecting offspring phenotype, and the contribution of nest-site choice to survival of the juvenile life stage. Overall, studies on the evolution and ecology of nest-site choice in reptiles and birds have much to offer each other in terms of both theoretical basis and applications to conservation and management. Incorporating knowledge gained from a range of taxa into our research, and testing hypotheses in one system that have demonstrated importance in other systems, will provide a richer understanding of the ecology and evolution of nest-site choice.

How Does Physical Activity Make You Feel Better? The Mediational Role of Perceived Health

Based on a sample of Spanish adults between the ages of 50 and 70 years, the aim of this paper is to establish to what extent physical activity is positively related to individual subjective well-being either directly or indirectly through its link with perceived health. In other words, we attempt to identify the role played by perceived health as a mediator of the relationship between the level of physical activity and individual happiness and life satisfaction. Moreover, a distinction was made between four activity domains of the individual lifetime involving physical activity: job, transportation, housework, and leisure time. The results show that physical activity in general is positively associated with a higher level of happiness and life satisfaction and that these positive relationships are partially mediated by an individual’s perceived health. Furthermore, we reached the conclusion that this association may vary depending on when the individual is engaged in physical activity. In particular, physical activity undertaken during leisure time has a significant relationship with individual happiness and life satisfaction in adults between the ages of 50 and 70.