Pattern Of Age-related Changes Research Articles

Sexual Behavior and Substance Use in Adolescence and Young Adulthood: Non-specific Associations Between a Range of Sexual Behaviors and Alcohol, Nicotine, and Marijuana Use

Sexual behaviors and substance use exhibit high rates of co-occurrence and similar patterns of age-related change, with typical initiation in middle adolescence followed by large increases in late adolescence and emerging adulthood. Because adolescent sexual behaviors are associated with negative health consequences including sexually-transmitted infections and substance use, adolescent sexual behaviors are often conceptualized within a health-risk framework. Sexual development, however, is a normative process important for healthy psychosocial adjustment, with the timing (early vs later initiation) and context (casual vs romantic partner) of sexual behaviors influencing their association with health risks. We tested whether seven common sexual behaviors could be conceptualized as markers along a continuum of sexual development (e.g., from kissing and making out to oral, vaginal, and anal sex) and then examined their associations with various measures of substance use in a sample of adolescents and young adults (N = 626; ages 13-22 years old). We found a 2-parameter logistic item response theory model provided a good fit to the prevalence and covariance among the sexual behaviors, with each behavior holding a different location on a trait representing the progression of sexual development. Each sexual behavior was associated with greater substance use even after adjusting for an early initiation of sexual behavior, current age, biological sex, and socioeconomic status. The results indicate that even normative sexual behaviors have strong and non-specific associations with substance use in adolescence and emerging adulthood.

Body Fat Mass, Percent Body Fat, Fat-Free Mass, and Skeletal Muscle Mass Reference Curves for Czech Children Aged 6-11 Years.

Background: Negative lifestyle trends are reflected in overweight and obese children, in which their lack of physical activity results in decreased muscle mass. This study aimed to define age- and sex-specific reference curves for body fat mass (BFM), skeletal muscle mass (SMM), fat-free mass (FFM), and percent body fat (%BF) in Czech children. Methods: Body composition was measured by segmental bioelectrical impedance (BIA, InBody 720). The research sample included 2093 children aged 6–11 years (1008 boys and 1085 girls). Only children whose parents provided informed consent were included. Statistical analysis was performed using SPSS v. 22. The statistical analysis was performed separately by age and sex. Anthropometric data were summarized as means and standard deviation. The percentile curves (P3, P10, P25, P50, P75, P90, and P97) of BFM, FFM, %BF, and SMM were calculated using the gamlss package in R 3.4.2 (R Foundation for Statistical Computing, Vienna, Austria). Results: This study developed age- and gender-specific percentile curves of SMM, FFM, BFM, and %BF for Czech children aged 6–11 years. During childhood, BFM and %BF increased in boys, peaking at approximately 11 years of age. Girls displayed a different pattern of age-related changes in BFM and %BF compared to that in boys. These parameters gradually increased during childhood. This pattern was also observed for SMM and FFM in both sexes. Conclusions: The purpose of this study was to serve as a reference to improve methods to evaluate body composition in Czech children and for comparison with studies worldwide.

Bone pathologies of modern non-draft cattle (Bos Taurus) in the context of grazing systems and environmental influences in the South Urals, Russia

ObjectiveTo assesses the patterns of age-related changes and bone pathologies in modern non-draft cattle to assist archaezooological analysis of draft cattle remains from antiquity. MaterialsThe study area is located in the steppe zone of the Southern Urals on the territory of Russia near the border with Kazakhstan. MethodsOver 300 bones of modern cattle were examined, mostly metapodials and phalanges, using standard archaeozoological methods to reconstruct the size of animals and to describe observed pathological conditions ResultsMinor lipping and exostoses of metapodials and phalanges, as well as ankylosis and hip joint eburnation, are common in modern non-draft cattle. In rare cases, lipping and exostoses are observed. ConclusionsThe observed changes in the bones of the distal extremities alone are insufficient for archaezooological reconstruction of cattle as draft animals. SignificanceThe study revealed problems in the reconstruction of etiologies of pathological conditions in draft cattle from archaeological sites. LimitationsLimited samples sizes and genetic differences between modern and archaeological populations can influence data recorded and derived conclusions. Future directionsContinued analyses of modern and archaeological faunal populations using multiple lines of evidence is encouraged.

Возрастные изменения головного указателя и размеров таламусов у мезоцефалов

Objective: to identify the pattern of age-related changes in the cerebral index and to determine the dynamics of trans-verse and longitudinal thalamic dimensions in mesocephalians according to magnetic resonance imaging. Material and methods. The data of magnetic resonance imaging of the brain of 78 people (37 men and 41 women) were analyzed. Depending on the age, all the subjects were divided into two groups. Group I consisted of 43 people (21 men and 22 women) of the first period of adulthood (29.19±0.73 years), group II - 35 people (16 men and 19 women) of senile age (78.97 ± 0.61 years). The cranial width index and cranial length index were calculated from the outermost protruding points on the axial section in 3D reconstruction mode. Morphometric examination of the thalamus included determining its linear dimensions in the axial plane: transverse (distances from the most distant medial and lateral points) and longitudinal (distances from the most distant anterior and posterior points). Results. Analysis of head index values revealed their statistically significant prevalence in men compared to women in the first period of adulthood (p<0.01). In old age, there were no sex differences, but there was a tendency for the values of the head index to prevail in men compared to women (p>0.05). Transverse and longitudinal dimensions of the thalamus in both hemispheres were found to be predominant in both males and females in the first period of adulthood in comparison with old age (p<0,01). When comparing the thalamic dimensions of the right and left hemispheres, both in the first period of adulthood and in senile age, no statistically significant differences in parameters were found, but there was a tendency for their predominance in the left thalamus (p>0.05). Conclusion. The results obtained in this study add to the information available in the scientific literature on age-related changes in the cerebral index as well as on the morphometric characteristics of the thalamus in both sexes during the first period of adulthood and in old age, making it possible to implement a personified approach in medical practice as well as to use these data in further clinical and basic research.

Looking Ahead and Working Hard: How School Experiences Foster Adolescents' Future Orientation and Perseverance.

The current study examined developmental change in future orientation and perseverance across childhood and adolescence. Drawing from stage-environment fit theory, the study examined how adolescents' perceptions of key school experiences (teacher support, school climate, high-quality organized activities, school transitions) and socioemotional competencies covaried across time. Using an accelerated longitudinal design, a diverse sample of 4,055 youth in grades 6-12 completed assessments at 4 time points. Latent growth curve analyses revealed future orientation and perseverance both followed a quadratic trajectory marked by growth in early adolescence, followed by a leveling off in later adolescence. School experiences positively covaried with socioemotional competencies. Findings provide insight into patterns of age-related change and offer implications for practices aimed at promoting future orientation and perseverance.

Individual and joint trajectories of change in bone, lean mass and physical performance in older men

BackgroundDeclines in bone, muscle and physical performance are associated with adverse health outcomes in older adults. However, few studies have described concurrent age-related patterns of change in these factors. The purpose of this study was to characterize change in four properties of muscle, physical performance, and bone in a prospective cohort study of older men.MethodsUsing repeated longitudinal data from up to four visits across 6.9 years from up to 4681 men (mean age at baseline 72.7 yrs. ±5.3) participating in the Osteoporotic Fractures in Men (MrOS) Study, we used group-based trajectory models (PROC TRAJ in SAS) to identify age-related patterns of change in four properties of muscle, physical performance, and bone: total hip bone mineral (BMD) density (g/m2) and appendicular lean mass/ht2 (kg/m2), by DXA; grip strength (kg), by hand dynamometry; and walking speed (m/s), by usual walking pace over 6 m. We also described joint trajectories in all pair-wise combinations of these measures. Mean posterior probabilities of placement in each trajectory (or joint membership in latent groups) were used to assess internal reliability of the model. The number of trajectories for each individual factor was limited to three, to ensure that the pair-wise determination of joint trajectories would yield a tractable number of groups as well as model fit considerations.ResultsThe patterns of change identified were generally similar for all measures, with three district groups declining over time at roughly similar rates; joint trajectories revealed similar patterns with no cross-over or convergence between groups. Mean posterior probabilities for all trajectories were similar and consistently above 0.8 indicating reasonable model fit to the data.ConclusionsOur description of trajectories of change with age in bone mineral density, grip strength, walking speed and appendicular lean mass found that groups identified by these methods appeared to have little crossover or convergence of change with age, even when considering joint trajectories of change in these factors.

Интенсивность изменений активности ферментов в тканях толстого кишечника у поросят в разные фазы постнатального онтогенеза

Annotation. The purpose is сlarification of patterns of age-related changes in the activity of aspartate aminotransferase (AsAT), alanine aminotransferase (AlAT), gamma-glutamyltransferase (GGT), α-amylase, alkaline phosphatase (AlP) and acid phosphatase (AP ) in tissues of different parts of the cecum in piglets of large white breed, in different phases of nutrition of the early postnatal period of systemic genesis of pig. Methods. Enzyme activities were determined spectrophotometrically (UV-1800) and using a set of reagents from the OJSC Vital Development Corporation, St. Petersburg. The activity of the enzymes AsAT and AlAT was determined by the method of Wrightman and Frenkel, GGT – by the unified colorimetric method at the “end point”. The α-amylase activity was measured by the method of Karavei. The level of AP, AlP was determined by the Bessey – Lowry – Brock method. Results. The degree of structural and chemical changes in the tissues of the cecum in piglets is high in the early phases of the postnatal period, during the first four months of life. They are especially pronounced in transitional phases of nutrition. The most intense age-related changes in metabolic processes in the tissues of the cecum in piglets were revealed between the milk and colostrum and first milk, between the first and second milk, between the third milk and milk-definitive, as well as between the first and second definitive phases. The timing of stabilization of the activity of individual enzymes in the tissues of the cecum is determined. They are detected in piglets in the later phases of feeding. The scientific novelty of the study lies in the fact that the nature and intensity of age-related changes in the activity of aspartate and alanine aminotransferases, gamma-glutamyl transferase, α-amylase, acidic and alkaline phosphatases in tissues of different parts of the cecum in growing piglets were revealed.

Long-Term Variability of Distortion-Product Otoacoustic Emissions in Infants and Children and Its Relation to Pediatric Ototoxicity Monitoring.

Distortion-product otoacoustic emissions (DPOAEs) provide a rapid, noninvasive measure of outer hair cell damage associated with chemotherapy and are a key component of pediatric ototoxicity monitoring. Serial monitoring of DPOAE levels in reference to baseline measures is one method for detecting ototoxic damage. Interpreting DPOAE findings in this context requires that test-retest differences be considered in relation to normal variability, data which are lacking in children. This study sought to (1) characterize normal test-retest variability in DPOAE level over the long time periods reflective of pediatric chemotherapy regimens for a variety of childhood ages and f2 primary frequencies using common clinical instrumentation and stimulus parameters; (2) develop level-shift reference intervals; and (3) account for any age-related change in DPOAE level or measurement error that may occur as the auditory system undergoes maturational change early in life. Serial DPOAE measurements were obtained in 38 healthy children (25 females and 13 males) with normal hearing and ranging in age from one month to 10 years at the initial (baseline) visit. On average, children were tested 5.2 times over an observation period of 6.5 months. Data were collected in the form of DP grams, in which DPOAE level was measured for f2 ranging from 1.4 to 10 kHz, using a fixed f2/f1 ratio of 1.22 and stimulus level of 65/55 dB SPL for L1/L2. Age effects on DPOAE level and measurement error were estimated using Bayesian regression of the longitudinal data. The raw and model-based distribution of DPOAE test-retest differences were characterized using means and standard error of the measurement for several ages and f2's. DPOAE test-retest differences for the children in this study are at the high end of those previously observed in adults, as reflected in the associated shift reference intervals. Further, although we observe substantial child-specific variation in DPOAE level, the pattern of age-related changes is highly consistent across children. Across a wide range of f2's, DPOAE level decreases by 3 to 4 dB from 1 to 13 months of age followed by a more gradual decline of <1 dB/year. An f2 of 6 kHz shows the smallest decrease during the early rapid maturation period. DPOAE measurement error is fairly constant with age. It is 3 to 4 dB at most f2's and is greater (indicating poorer reliability) at 1.5, 8, and 10 kHz. DPOAE level decreases with childhood age, with the greatest changes observed in the first year of life. Maturational effects during infancy and greater measurement error at very low and high f2's affect test-retest variability in children. An f2 of 6 kHz shows minimal maturation and measurement error, suggesting it may be an optimal sentinel frequency for ototoxicity monitoring in pediatric patients. Once validated with locally developed normative data, reference intervals provided herein could be used to determine screen fail criteria for serial monitoring using DPOAEs. Employing state-of-the-art calibration techniques might reduce variability, allowing for more sensitive screen fail criteria.

Age- and Sex-Specific Changes in Lower-Limb Muscle Power Throughout the Lifespan.

Our main goal was to evaluate the pattern and time course of changes in relative muscle power and its constituting components throughout the life span. A total of 1,305 subjects (729 women and 576 men; aged 20-93 years) participating in the Copenhagen Sarcopenia Study took part. Body mass index (BMI), leg lean mass assessed by dual-energy X-ray absorptiometry (DXA), and leg extension muscle power (LEP) assessed by the Nottingham power rig were recorded. Relative muscle power (normalized to body mass) and specific muscle power (normalized to leg lean mass) were calculated. Segmented regression analyses were used to identify the onset and pattern of age-related changes in the recorded variables. Relative muscle power began to decline above the age of 40 in both women and men, with women showing an attenuation of the decline above 75 years. Relative muscle power decreased with age due to (i) the loss of absolute LEP after the fourth decade of life and (ii) the increase in BMI up to the age of 75 years in women and 65 years in men. The decline in absolute LEP was caused by a decline in specific LEP up to the age of 75 in women and 65 in men, above which the loss in relative leg lean mass also contributed. Relative power decreased (i) above 40 years by the loss in absolute power (specific power only) and the increase in body mass, and (ii) above ~70 years by the loss in absolute power (both specific power and leg lean mass).

Возрастная динамика показателей вербальной и образной креативности школьников

Despite long-term studies of children’s creative abilities, this area remains relevant due to changes in learning programs and socio-economic conditions of education, which influence the amount of knowledge the child needs and the flexibility of its use. The development of psychometric approaches to creativity enables us to consider the age-related dynamics of decision-making, which reflect the child’s ability to think critically and to alter their strategic approach to solving a problem, as the search for an original solution requires the use of knowledge from different subject areas. In this paper we discuss patterns of age-related changes in the flexibility of schoolchildren’s thinking observed while testing verbal and figurative creativity with a limited time set for performing tasks and different levels of stereotype pressure involving stimuli that are repetitive or ones that belong to different semantic categories. The study involved 155 11–13 year old secondary school children. Creativity indicators were determined by means of Torrens’ subtests “Circles” and “Incomplete figures”, Guilford’s “Unusual use of an ordinary subject” method, and a verbal test of sentence composition, which involved combining words from distant semantic categories. It was established that when testing creativity while applying a time limit and repetitive stimuli, originality and fluency indicators correlate positively regardless of the child’s age and verbal or figurative nature of the stimuli. The detected age-related decrease in fluency may indicate the development of inhibitory control functions and critical thinking, which, however, does not lead to an increase in originality, which may be explained by insufficiently developed flexibility. The highest creativity indicators during tests by repetitive stimuli were observed in eleven-year-olds, and for non-repeating ones, in twelve-year-olds. In addition, the effectiveness of creative task performance appears to be determined by gender. Girls demonstrated better results while performing verbal tasks, specifically, a higher degree of originality in composing sentences and names for completed figures. The authors conclude that the age-related dynamics of creativity in schoolchildren aged 11–13 years may be associated with the specifics of experimental tasks, i. e. with the nature of the task, and the testing conditions.

Differential developmental courses of implicit and explicit biases for different other-race classes.

We investigated the developmental courses of both implicit and explicit racial biases in relation to the perceived social status of outgroups. We did so by assessing these biases among Chinese participants (N = 200, age range from 4- to 19-year-olds) toward 2 different other-race groups that differ in terms of perceived social status (i.e., Whites and Blacks). At the youngest age, children showed both implicit anti-White and anti-Black bias at similar levels. However, these biases had different patterns of age-related change: implicit anti-Black bias remained strong and stable over time, whereas implicit anti-White bias declined after age 10. For explicit bias, children showed a decline in anti-Black and anti-White bias. Implicit and explicit biases were uncorrelated at all ages. The observed age-related changes demonstrate that it is possible for patterns of biases toward different races to diverge with age, and that perceived social status may contribute to the differential developmental patterns. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

AGE-RELATED CHANGES IN HEART RATE VARIABILITY AMONG RESIDENTS OF THE RUSSIAN NORTH

In this paper we present new models of homeostasis as uninterrupted and chaotic changes of functional systems parameters of human body. The aim of the study is to establish the statistical and chaotic patterns of age-related changes in heart rate variability of residents of the North of the Russian Federation. Methods. The main outcomes variable was R-R interval measured using pulse oximeter "EL0KS-01". Data on other cardiovascular system functional parameters were also obtained. The new approach for the analysis we present is based on calculation of coordinates xi which are included in a common vector x(t). The new presentation of complex systems evolution for aboriginal residents and newcomers was presented. We studied permanent female residents of the Ugra region and newcomers. Results. The result of the study showed that according to a new theory of chaos-self organization there are substantial differences between dynamics of quasi-attractors of cardio-vascular system of newcomers. Age-related changes in the area of quasi-attractors demonstrate significant changes that satisfy the condition of a two-fold change in R-R intervals with age. Many people surveyed after 55 years give an increase in their quasi-attractor, which is inconsistent with the dynamics of change in the area of quasi-attractor S from time T for Khanty women and does not guarantee real longevity. The dynamic is not typical for normal aging changes of functional system parameters xi (especially R-R intervals x(t)). Conclusions. It is established that these quasi-attractors decrease with age (their area S), which is typical for the parameters of the R-R intervals. The dependence of the rate of age evolution of R-R intervals for aboriginal women is obtained, which can be used as a standard of normal aging of the human body in the Russian North.

Age-Related Changes in the Tissue Antioxidant System of Canids

The study was aimed at determining tissue antioxidant levels in three closely related albeit ecologically different Canidae species: the raccoon dog (Nyctereutes procyonoides), silver fox (Vulpes vulpes) and blue fox (Vulpes lagopus), aged 0.5 (juvenile), 1.5–3.5 (adult) and 4.5–5.5 (aging) years. Some tested parameters were found to be species-specific: as compared to other species, raccoon dogs and blue foxes exhibited higher α-tocopherol levels in the liver and kidney, blue foxes were characterized by a higher activity of the antioxidant enzymes in the kidneys, while silver foxes had higher glutathione (GSH) levels in the liver, kidneys and heart. The antioxidant defense system in all organs of the tested species was distinguished by a relative stability. In raccoon dogs, the retinol level in the heart increased with age, while in silver foxes it is only superoxide dismutase (SOD) activity in the kidneys and the GSH level in the liver and heart that underwent significant changes with age. In blue foxes, aging was accompanied by an increase in liver retinol and kidney α-tocopherol levels as well as a decrease in the kidney GSH level. Besides, sex differences were found in antioxidant levels in blue foxes. Our results are consistent with the data obtained by other authors for other animal species, indicating a mixed pattern of age-related changes in the antioxidant defense system of carnivorous canids. While some antioxidants rise and the other fall, the functionality of the whole system does not appear to be disturbed. Ecological and physiological features of different mammalian species may determine the adaptive potential of animals and affect the tested indicators of the antioxidant defense system during late postnatal ontogenesis.

Genetic risk for schizophrenia is associated with substance use in emerging adulthood: an event-level polygenic prediction model.

Emerging adulthood is a peak period of risk for alcohol and illicit drug use. Recent advances in psychiatric genetics suggest that the co-occurrence of substance use and psychopathology arises, in part, from a shared genetic etiology. We sought to extend this research by investigating the influence of genetic risk for schizophrenia on trajectories of four substance use behaviors as they occurred across emerging adulthood. Young adult participants of non-Hispanic European descent provided DNA samples and completed daily reports of substance use for 1 month per year across 4 years (N = 30 085 observations of N = 342 participants). A schizophrenia polygenic score was included in two-level hierarchical linear models designed to test associations between genetic risk for schizophrenia, participant age, and four substance use phenotypes. Participants with a greater schizophrenia polygenic score experienced greater age-related increases in the likelihood of using substances across emerging adulthood (p < 0.005). Additionally, our results suggest that the polygenic score was positively associated with participants' overall likelihood to engage in illicit drug use but not alcohol-related substance use. This study used a novel combination of polygenic prediction and intensive longitudinal methods to characterize the influence of genetic risk for schizophrenia on patterns of age-related change in substance use across emerging adulthood. Results suggest that genetic risk for schizophrenia has developmentally specific effects on substance use behaviors in a non-clinical population of young adults.

Evolution of spatial and temporal features of functional brain networks across the lifespan

Development and aging are associated with functional changes in the brain across the lifespan. These changes manifest in a variety of spatial and temporal features of resting state functional MRI (rs-fMRI) but have seldom been explored exhaustively. We present a comprehensive study assessing age-related changes in spatial and temporal features of blind-source separated components identified by independent vector analysis (IVA) in a cross-sectional lifespan sample (ages 6–85 years). We show that while large-scale network configurations remain consistent throughout the lifespan, changes persist in both local and global organization of these networks. We show that the spatial extent of the majority of functional networks exhibits linear decreases and both positive and negative quadratic trajectories across the lifespan. Network connectivity revealed nuanced patterns of linear and quadratic relationships with age, primarily in higher order cognitive networks. We also show divergent age-related patterns across the frequency spectrum in lower and higher frequencies. Taken together, these results point to the presence of sophisticated patterns of age-related changes that have previously not been considered collectively. We suggest that established patterns of lifespan changes in rs-fMRI features may be driven by changes in the spectral composition of BOLD signals.

Structure and Dynamics of Table Tennis Players Competitive Activity at the Stages of Long-Term Athlete Development

The problem of developing the theoretical and methodological foundations for long-term young athletes’ development is closely linked with the problem of improving the training process as a whole and it is one of the main problems in the modern science of physical education and sports training. In different years Ozolin (1970), Matveev (1995), Filin (1995), Platono (1997) and other specialists developed a wide range of issues concerning the sports reserve preparation . Establishing of the strict correlation between the system of the long-term athlete development management and specific requirements of the competitive activity in the specific sports disciplines is proposed as one of the main directions of further improvement of the modern sports training methods, which implies a comprehensive study of the multi-year structure and dynamics of competitive activity and athletes' proficiency. In sport games, the solution of this problem is particularly difficult, on the one hand, due to the lack of an objectively measurable result, and on the other hand, due to dependence of the latter on a whole range of factors of different nature, with an uneven degree of compensability and interdependency at various stages of long-term athlete development. The scientific novelty of the study is determined by solving one of the most important problems of sports theory and methodology associated with identifying and studying the patterns of age-related changes in the structure of competitive team activity and athletes’ proficiency in table tennis, which make it possible to significantly improve the management of the long-term development of sports reserve due to the development and introduction into practice of a scientifically based model of building the long-term athlete development and the system of the young athletes’ prospects projection in table tennis .

Association of serum bilirubin with longevity: Evidence from a retrospective longitudinal study and cross-sectional data

Bilirubin is a potent antioxidant and an important anti-inflammatory factor. Therefore, there has been an increasing focus on serum bilirubin as a negative risk factor of cardiovascular mortality in men and an indicator of improved survival in both sexes, but the direct mechanisms of these links and the causes of sex differences are not well understood. Moreover, the evidence from longitudinal studies on effects of bilirubin on longevity is limited. In this study, we retrospectively analyzed two groups of older adults to explore age-dependent changes in serum bilirubin levels and their associations with long-term survival in both sexes. Longitudinal data from 142 individuals (68 men and 74 women) aged 45 to 70 years were compared with cross-sectional data from 225 individuals (113 men and 112 women). The latter group was divided into four categories of survival, i.e. 53, 63, 68, and 76+ based on data on lifespan. ANOVA, t-test, and regression analysis were run. The analysis of the longitudinal data showed an increase in serum total bilirubin levels in men (0.3038e0.093x, R2 = 0.667) and women (0.1838e0.0187x, R2 = 0.950), while the analysis of cross-sectional data revealed a U-shaped pattern of age-related changes in men (0.001x2 - 0.1263x + 4.4524, R2 = 0.999) but an inverted U-shaped pattern in women (0.0006x2 + 0.072x - 1.6924, R2 = 0.195). On balance, these results suggest that elevated but normal bilirubin levels might confer a survival advantage in older men but not women. Alternatively, the positive relationship between serum total bilirubin and lifespan was not causal but coincidental. Further studies are needed to elucidate the direct mechanisms of the association between serum bilirubin levels and longevity in elderly people of both sexes.

Age-related changes in the dynamics of fear-related regulation in early childhood.

Self-regulation is a dynamic process wherein executive processes (EP) delay, minimize or desist prepotent responses (PR) that arise in situations that threaten well-being. It is generally assumed that, over the course of early childhood, children expand and more effectively deploy their repertoire of EP-related strategies to regulate PR. However, longitudinal tests of these assumptions are scarce in part because self-regulation has been mostly studied as a static construct. This study engages dynamic systems modeling to examine developmental changes in self-regulation between ages 2 and 5 years. Second-by-second time-series data derived from behavioral observations of 112 children (63 boys) faced with novel laboratory-based situations designed to elicit wariness, hesitation, and fear were modeled using differential equation models designed to capture age-related changes in the intrinsic dynamics and bidirectional coupling of PR (fear/wariness) and EP (strategy use). Results revealed that dynamic models allow for the conceptualization and measurement of fear regulation as intrinsic processes as well as direct and indirect coupling between PR and EP. Several patterns of age-related changes were in line with developmental theory suggesting that PR weakened and was regulated more quickly and efficiently by EP at age 5 than at age 2. However, most findings were in the intrinsic dynamics and moderating influences between PR and EP rather than direct influences. The findings illustrate the precision with which specific aspects of self-regulation can be articulated using dynamic systems models, and how such models can be used to describe the development of self-regulation in nuanced and theoretically meaningful ways.

Age-related changes of physiological performance and survivorship of bank voles selected for high aerobic capacity

Variation in lifespans is an intriguing phenomenon, but how metabolic rate influence this variation remains unclear. High aerobic capacity can result in health benefits, but also in increased oxidative damage and accelerated ageing. We tested these contradictory predictions using bank voles (Myodes=Clethrionomys glareolus) from lines selected for high swim-induced aerobic metabolism (A), which had about 50% higher maximum metabolic rate and a higher basal and routine metabolic rates, than those from unselected control lines (C). We measured sprint speed (VSmax), forced-running maximum metabolic rate (VO2run), maximum long-distance running speed (VLmax), running speed at VO2run (VVO2), and respiratory quotient at VO2run (RQ) at three age classes (I: 3–5, II: 12–14, III: 17–19months), and analysed survivorship. We asked if ageing, understood as the age-related decline of the performance traits, differs between the A and C lines. At age class I, voles from A lines had 19% higher VO2run, and 12% higher VLmax, but tended to have 19% lower VSmax, than those from C lines. RQ was nearly 1.0 for both A and C lines. The pattern of age-related changes differed between the lines mainly between age classes I and II, but not in older animals. VSmax increased by 27% in A lines and by 10% in C lines between age class I and II, but between classes II and III, it increased by 16% in both selection directions. VO2run decreased by 7% between age class I and II in A lines only, but in C lines it remained constant across all age classes. VLmax decreased by 8% and VVO2 by 12% between age classes II and III, but similarly in both selection directions. Mortality was higher in A than in C lines only between the age of 1 and 4months. The only trait for which the changes in old animals differed between the lines was RQ. In A lines, RQ increased between age classes II and III, whereas in C lines such an increase occurred between age classes I and II. Thus, we did not find obvious effects of selection on the pattern of ageing. However, the physiological performance and mortality of bank voles remained surprisingly robust to ageing, at least until the age of 17–19months, similar to the maximum lifespan under natural conditions. Therefore, it is possible that the selection could affect the pattern of ageing in even older individuals when symptoms of senility might be more profound.

Trajectories of Life Satisfaction and their Predictors among Korean Older Adults

BackgroundAmong older adults, life satisfaction (LS) correlates with health, mortality, and successful ageing. As various potential threats to LS tend to increase with advancing years, patterns of age-related changes in LS among older adults remain inconsistent. This study aimed to identify LS trajectories in older adults and the characteristics of individuals who experience them.MethodsLarge-scale, nationally representative, longitudinal data collected from 2005 to 2013 were analyzed for this study. The outcome measure was a summary of multidimensional domains influencing LS: health, finance, housing, neighbor relationships, and family relationships. Latent class growth models and logistic regression models were used to identify trajectory groups and their predictors, respectively.ResultsWithin 3517 individuals aged 65 or older, five trajectories were identified across eight follow-up years: “low-stable” (TG1; n = 282; 8%), “middle-stable” (TG2; n = 1146; 32.6%), “improving” (TG3; n = 75; 2.1%), “upper middle-stable” (TG4; n = 1653; 47%), and “high” (TG5; n = 361; 10.3%). High trajectory individuals more frequently had higher education, financial security, good physical health, and good mental health than those in the stable, but less satisfied, groups. Similarly, compared to the largest group (upper middle-stable trajectory), individuals in the low-stable or middle-stable trajectory group not only had poorer physical and mental health but were more likely to be living alone, financially stressed, and residing in urban locations. Individuals with improving trajectory were younger and in poorer mental health at baseline compared to the upper middle-stable trajectory group.ConclusionLife satisfaction in the older follows distinct trajectories. For older adults, trajectories are stable over time and predictable, in part, from individual characteristics. Knowledge of these patterns is important for effective policy and program development.