Human development reportedly includes critical and sensitive periods during which environmental stressors can affect traits that persist throughout life. Controversy remains over which of these periods provides an opportunity for such stressors to affect health and longevity. The elaboration of reproductive biology and its behavioral sequelae during adolescence suggests such a sensitive period, particularly among males. We test the hypothesis that life expectancy at age 20 among males exposed to life-threatening stressors during early adolescence will fall below that among other males. We apply time-series methods to cohort mortality data in France between 1816 and 1919, England and Wales between 1841 and 1919, and Sweden between 1861 and 1919. Our results indicate an inverse association between cohort death rates at ages 10-14 and cohort life expectancy at age 20. Our findings imply that better-informed and more strategic management of the stressors encountered by early adolescents may improve population health.
Present-day society has produced changes in family living patterns and conditions and this has resulted in new stressors and health problems. Most children and adolescents with chronic diseases and disabilities, who were previously cared for at hospitals and institutions for long periods, are now integrated in society and they are expected to live a normal life in the conditions that currently prevail. The number of young people with long-term illnesses/disability has increased worldwide during the last decades. There is lack of studies relating to the way young people regard their daily lives and factors that are important for their well-being. The aim of this study was to describe the meaning of feeling good in daily life in adolescents living with a long-term illness or disability. Eight boys and seven girls, aged between 12 and 19 years, with different conditions of long-term illness or disability, participated in the study. Tape-recorded interviews were conducted between the years 2003-2004 and the data were analysed using content analysis. The results revealed that the adolescents with long-term illness generally experienced well-being like everybody else. Three themes were found to be important in order to feel good: 'a feeling of acceptance of illness/disability as a natural part of life', 'a feeling of support' and 'a feeling of personal growth'. This study concludes that adolescents with long-term illness or disabilities experience well-being when they are allowed to prepare for living a normal life integrated in society.
Physical and sexual developments were determined in 285 schoolchildren aged 12 to 17 years from the town of Karabash, an area of ecological ill-being in the environmental levels of heavy metal salts. The atmospheric air pollution was in parallel monitored at route observational stations. It was found that 39% of the schoolchildren had disharmonic physical development; of them a fourth had lower body weight and decreased chest circumference with normal growth indices. The girls were observed to have a high frequency of a microsomatotype of harmonic physical development and disharmonic physical development mainly at the expense of underweight (52.9% of all the disharmonically developed girls) as compared with the boys. There was a preponderance of female adolescents with sexual retardation. In the population of Karabash girls, the mean age at menarche was 12 years and 9 months +/- 1.5 months.
Interinstitute Laboratory for Comparative Ecological-Physiological Studies, I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Science, St. Petersburg, Russia. email@example.com
The central mechanisms of involuntary and voluntary regulation of attention in schoolchildren from the northern region were studied using a method based on the P300 wave of evoked brain potentials (the oddball paradigm). Data were compared with results obtained from psychological tests. Differences in the organization of EP were seen in the "passive" and active (counting) perception of deviant stimuli. Three components were identified within the time envelop of the P300 wave, two of which dominated in the frontal and one in the parietal area of the cerebral cortex. The latency of the P300 wave decreased with age in the children, reflecting increased rates of information processing and increases in the volume of operative memory. In passive perception, the statistical relationship characterized by a reduction in P300 latency with age was significant for leads in the central, temporal, parietal, and occipital areas; in active perception, this applied to all areas including the frontal. The most significant changes in P300 parameters were seen in children aged from seven to 12 years, indicating that this period can be regarded as "critical" in the development of learning skills. The roles of the parietal and frontal areas of the cortex in the mechanisms of involuntary and voluntary regulation of attention are discussed, along with the possibility of using the P300 method to identify children with delayed rates of development of voluntary attention in population studies.
The morphofunctional age-related development of the brain was studied in schoolchildren living in the difficult climatological-geographic and socioeconomic conditions of the north (Arkhangel'sk region). Of the 62 students in country middle schools, EEG amplitude-frequency, time, and spatial measures corresponded to age norms (European norms) in only 10 cases (16%). A further 26 children (53%) showed minor abnormalities in the form of an inadequate degree of organization of the temporospatial EEG pattern, mainly in the frontal and temporal lobes of the brain, with increases in the levels of the theta and delta rhythms, and the absence of any marked "functional nucleus" in the alpha rhythm. In the remaining 14 children (29%), EEG measures showed more marked delays in mental development (DMD), which were combined with learning difficulties and abnormal behavior. The retardation in the morphofunctional development of the brain in northern children averaged 1.5-2 years, which coincides with delays in hormonal and physical development described by other authors.
The paper presents data on the formation of spatial synchronization of brain potentials in 91 children aged 7-18 years living in European North of Russia. We estimated coherence values for 19 derivations (pair 171) in five EEG frequency bands (delta, theta, alpha-1, alpha-2 and beta). We described age-related changes, gender differences and topical specific features of the formation of coherence in the left and right hemispheres, and in inter- and intrahemispheric synchronization. We carried out computer assessment of the differences in EEG coherence between three age groups of children in order to determine criteria for identification of children with retarded formation of spatial organization of local EEG processes. Age-related changes in the structure of EEG patterns observed in the study reflect the processes of morphofunctional brain development in children and adolescents at different stages of postnatal ontogenesis under severe conditions of northern climate.
Using unified Bunak's method, age- and gender-related growth dynamics of anthropometric parameters was evaluated in 2428 schoolchildren aged 7-18 years living in the city of Nal'chik. The first curve decussation of the absolute values studied, indicative of the beginning of puberty in girls occured at the age of 9.5 to 11.5 years; the second, which is typical for the puberty in boys, took place at the age of 11.5 to 14.5. After the second curve decussation (after 15 years), all the investigated parameters in boys, with the exception of pelvic width, were significantly higher as compared to those in girls; maximal differences were detected at the age of 18. The girls pass ahead of the boys in their development by 2-3 years. Quetelet II index values were found to be normal both in boys and girls at 18 years, indicating the moderate degree of development of subcutaneous adipose tissue.
Cognitive impairment has been associated with excessive alcohol use, but its neural basis is poorly understood. Chronic excessive alcohol use in adolescence may lead to neuronal loss and volumetric changes in the brain. Our objective was to compare the grey matter volumes of heavy- and light-drinking adolescents.
This was a longitudinal study: heavy-drinking adolescents without an alcohol use disorder and their light-drinking controls were followed-up for 10 years using questionnaires at three time-points. Magnetic resonance imaging was conducted at the last time-point.
The area near Kuopio University Hospital, Finland.
The 62 participants were aged 22-28 years and included 35 alcohol users and 27 controls who had been followed-up for approximately 10 years.
Alcohol use was measured by the Alcohol Use Disorders Identification Test (AUDIT)-C at three time-points during 10 years. Participants were selected based on their AUDIT-C score. Magnetic resonance imaging was conducted at the last time-point. Grey matter volume was determined and compared between heavy- and light-drinking groups using voxel-based morphometry on three-dimensional T1-weighted magnetic resonance images using predefined regions of interest and a threshold of P