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Adolescent Years (adolescent + year)
Selected AbstractsTHE DETERMINANTS OF LAWS RESTRICTING YOUTH ACCESS TO TOBACCOCONTEMPORARY ECONOMIC POLICY, Issue 1 2009CRAIG A. GALLET Since many smokers begin consuming tobacco products in their adolescent years, many states have adopted a variety of restrictions on youth access to tobacco, which studies show reduces the demand for tobacco among this cohort. This paper takes a different track by addressing the demand for youth access restrictions. Specifically, using a random effects Probit procedure, which controls for the endogeneity of cigarette consumption and taxation, we examine the determinants of nine methods commonly used by states to restrict youth access to tobacco. (JEL H70, I18) [source] Longitudinal study of urinary albumin excretion in young diabetic patients,-Wessex Diabetic Nephropathy ProjectDIABETIC MEDICINE, Issue 5 2001S. Twyman Summary Aims This study was established to follow changes in albumin/creatinine ratio (ACR) and to determine the prevalence and degree of progression of microalbuminuria (MA) or of clinical proteinuria (CP) in children with Type 1 diabetes. The study has investigated subjects for up to 12 years in establishing the correlation between MA and gender, age, duration of diabetes and glycated haemoglobin (HbA1c). The study has defined clinical cut-offs for MA in daytime clinic urine samples in young diabetic subjects. Methods Three hundred and sixty-one patients were involved in the study, with 221 (61.2%) having over six sets of data. Urine samples were collected at routine annual clinic visits and analysed without prior freezing for ACR. Blood samples were taken for HbA1c measurement. Data including sex, age and duration of diabetes were recorded. Results A random clinic ACR of <,4.5 mg/mmol (males) and 5.2 mg/mmol (females) creatinine was used as the ,clinical cut-off' to define the presence of MA. The presence of MA was independent of HbA1c and duration of diabetes but appeared be associated with the adolescent years (> 10 years). There was little evidence of progression from normoalbuminuria to MA, or from MA to CP. Of patients aged 10,18 years, 30.9% of males and 40.4% of females had one or more episodes of MA. Conclusions Persistent MA and random episodes of MA or CP may be associated with the adolescent years but not with duration of diabetes. Further study will reveal if the substantial increases in ACR sometimes seen during adolescence are predictive of diabetic nephropathy. Clinical cut-offs of <,4.5 and <,5.2 mg/mmol creatinine for males and females, respectively, are suggested for the interpretation of changes in ACR in random urine samples in young people with Type 1 diabetes. [source] Scapular development from the neonatal period to skeletal maturity: A preliminary studyINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 5 2007C. Rissech Abstract An understanding of the basic growth rates and patterns of development for each element of the human skeleton is important for a thorough understanding and interpretation of data in all areas of skeletal research. Yet surprisingly little is known about the detailed ontogenetic development of many bones, including the scapula. With the intention of describing the changes that accompany postnatal ontogeny in the scapula and algorithms to predict sub-adult age at death, this communication examines the development of the scapula through nine measurements (3 from the glenoidal area, 4 from the body and 2 related to the spinous process) by polynomial regression. Data were collected from 31 of the individuals that comprise the Scheuer Collection, which is housed at the University of Dundee (Scotland). Four of the derived mathematical curves (scapular length, infra- and suprascapular height and spine length) displayed linear growth, whilst three (maximum length of the glenoid mass, acromial width and scapular width) were best expressed by a second-degree polynomial and two (maximum and middle diameter of the glenoidal surface) by a third-degree polynomial. All single measurements proved useful in the prediction of age at death, although derived indices proved to be of limited value. In particular, scapular width, suprascapular height and acromial width showed reliable levels of age prediction until late adolescent years. Copyright © 2007 John Wiley & Sons, Ltd. [source] Calcium Accretion in Girls and Boys During Puberty: A Longitudinal AnalysisJOURNAL OF BONE AND MINERAL RESEARCH, Issue 11 2000Donald A. Bailey Abstract The primary purpose of this study was to estimate the magnitude and variability of peak calcium accretion rates in the skeletons of healthy white adolescents. Total-body bone mineral content (BMC) was measured annually on six occasions by dual-energy X-ray absorptiometry (DXA; Hologic 2000, array mode), a BMC velocity curve was generated for each child by a cubic spline fit, and peak accretion rates were determined. Anthropometric measures were collected every 6 months and a 24-h dietary recall was recorded two to three times per year. Of the 113 boys and 115 girls initially enrolled in the study, 60 boys and 53 girls who had peak height velocity (PHV) and peak BMC velocity values were used in this longitudinal analysis. When the individual BMC velocity curves were aligned on the age of peak bone mineral velocity, the resulting mean peak bone mineral accrual rate was 407 g/year for boys (SD, 92 g/year; range, 226,651 g/year) and 322 g/year for girls (SD, 66 g/year; range, 194,520 g/year). Using 32.2% as the fraction of calcium in bone mineral, as determined by neutron activation analysis (Ellis et al., J Bone Miner Res 1996;11:843-848), these corresponded to peak calcium accretion rates of 359 mg/day for boys (81 mg/day; 199,574 mg/day) and 284 mg/day for girls (58 mg/day; 171,459 mg/day). These longitudinal results are 27,34% higher than our previous cross-sectional analysis in which we reported mean values of 282 mg/day for boys and 212 mg/day for girls (Martin et al., Am J Clin Nutr 1997;66:611-615). Mean age of peak calcium accretion was 14.0 years for the boys (1.0 years; 12.0-15.9 years), and 12.5 years for the girls (0.9 years; 10.5-14.6 years). Dietary calcium intake, determined as the mean of all assessments up to the age of peak accretion was 1140 mg/day (SD, 392 mg/day) for boys and 1113 mg/day (SD, 378 mg/day) for girls. We estimate that 26% of adult calcium is laid down during the 2 adolescent years of peak skeletal growth. This period of rapid growth requires high accretion rates of calcium, achieved in part by increased retention efficiency of dietary calcium. [source] Adolescent Transitions to Young Adulthood: Antecedents, Correlates, and Consequences of Adolescent EmploymentJOURNAL OF RESEARCH ON ADOLESCENCE, Issue 3 2001Tama Leventhal The antecedents, correlates, and consequences of adolescent employment were investigated in a sample of 251 low-income, African American youth that were followed since birth. The youth (age: M at preschool = 4.89, SD= .70; M at adolescence = 16.44, SD= .66; M at transition to adulthood = 19.36, SD= .76; and M at early adulthood = 27.67, SD= .75) were the firstborn children of African American teenage mothers who gave birth in Baltimore in the 1960s. Analyses examined the antecedents and correlates of age of entry into employment and stability of employment during adolescence. The associations of adolescent work experiences with subsequent adult education and employment outcomes also were considered. Findings indicate that among this sample of low-income, African American youth, those who repeated a grade in school during middle childhood were more likely to enter the workforce at later ages than their peers who did not repeat a grade. The small subset of adolescents who never worked (n= 12) appear to be markedly more disadvantaged than their peers who worked. At the transition to adulthood, adolescents who entered the workforce earlier were more likely to complete high school than their peers. In addition, stable employment during the adolescent years had more beneficial effects on young men's chances of attending college than young women's postsecondary education. This pattern of findings is consistent with ethnographic accounts of adolescent employment among poor, minority, urban youth. [source] Emanuel Miller Lecture: Early onset depressions , meanings, mechanisms and processesTHE JOURNAL OF CHILD PSYCHOLOGY AND PSYCHIATRY AND ALLIED DISCIPLINES, Issue 12 2008Ian M. Goodyer Background:, Depressive syndromes in children and adolescents constitute a serious group of mental disorders with considerable risk for recurrence. A more precise understanding of aetiology is necessary to improve treatment and management. Methods:, Three neuroactive agents are purported to be involved in the aetiology of these disorders: serotonin, brain-derived neurotrophic factor and cortisol. A literature review was conducted to determine their contributions to the emergence of unipolar depressions in the adolescent years. Results:, Serotonin, brain-derived neurotrophic factor and cortisol may operate in concert within two distinct functional frameworks: atypical early epigenesis arising in the first few years of life and resulting in the formation of a vulnerable neuronal network involving in particular the amygdala and ventral prefrontal cortex. Individuals with this vulnerability are likely to show impaired mood regulation when faced with environmental demands during adolescence and over the subsequent decades; and acquired neuroendangerment, a pathological brain process leading to reduced synaptic plasticity, in particular in the hippocampus and perhaps the nucleus accumbens and ventral tegmentum. This may result in motivational, cognitive and behavioural deficits at any point in the lifespan most apparent at times of environmental demand. Conclusions:, The characteristics, course and outcome of a depressive episode may depend on the extent of the involvement of both atypical early neurogenesis and acquired neuroendangerment. [source] Assessing alcohol guidelines in teenagers: results from a 10-year prospective studyAUSTRALIAN AND NEW ZEALAND JOURNAL OF PUBLIC HEALTH, Issue 2 2009Elya Moore Abstract Objective: To assess the value of drinking guidelines applied in adolescence for predicting alcohol-related outcomes in young adulthood. Methods: We conducted an eight-wave, population-based cohort study of 696 males and 824 females in Victoria between 1992 and 2003. Adolescent drinking was assessed at five survey waves, in six month intervals, from mean age 15.4-17.4 years. We created three measures of adolescent alcohol use using categories from NHMRC drinking guidelines: risky/high-risk drinking in the short and long term (2001), and high-risk drinking (2007). Each measure was defined according to the number of waves at which drinking was reported at or above the designated level during adolescence: non-drinkers, zero waves (low-risk drinkers), one wave, and 2+ waves. Alcohol use disorders and alcohol-related sexual behaviours were assessed at mean age 24.1 years. Results: Fourteen per cent of males and 17% of females were non-drinkers during adolescence. Using each NHMRC drinking guideline, the prevalence of each outcome for men increased with the number of waves at which drinking was reported above the low-risk level (p-values <0.007). The association was less clear for women. The prevalence of each outcome was lower among the nondrinkers compared to the low-risk drinkers for both men and women. Conclusions and implications: These findings support the emphasis in the NHMRC guidelines on abstaining from alcohol during the adolescent years. Any drinking, even at the low-risk level, may not be appropriate in adolescence. However, refinements that could better capture the risk of adolescent drinking in women would be useful. [source] | |||||||||||||