Age Cohorts (age + cohort)

Distribution by Scientific Domains
Distribution within Medical Sciences

Selected Abstracts

Recent Changes in the Workforce and Practice of Dermatologic Surgery

BACKGROUND The increasing number of American College of Mohs Surgery (ACMS) fellowship positions over the last decade has resulted in a greater number of fellowship-trained surgeons in dermatologic surgery. METHODS Mohs micrographic fellowship-trained surgeons (MMFTSs) and non-Mohs fellowship-trained surgeons performing Mohs micrographic surgery (NMMFTSs) were compared using the American Academy of Dermatology Practice Profile Survey (2002/05). An analysis of recent Mohs fellowship classes was also performed. RESULTS In 2005, there was an equivalent proportion of MMFTSs and NMMFTSs in the workforce (ratio MMFTS:NMMFTS=0.9) but, in 2005, there was a shift in the youngest age cohort (29,39) to a greater proportion of MMFTSs (MMFTS:NMMFTS=1.55). In 2005, the youngest MMFTSs (29,39) were more likely to be female (47.1%) than of MMFTSs overall (24%). MMFTSs were 5 times as likely to be in full-time academic positions and performed 2 to 3 times as many Mohs cases per week as NMMFTSs. CONCLUSIONS Consistent with demographic shifts in dermatology, differences have emerged in the demographics, surgical volumes, and settings of MMFTSs and NMMFTSs. Recent increases in the ACMS fellowship positions have resulted in a greater proportion of MMFTSs among younger dermatologic surgeons. It will be important to follow how this increase in fellowship trainees affects the dermatologic surgery workforce. [source]

Targets and Tools in Dutch Access Policies

Frans Kaiser
In 2004 the Dutch Ministry of Education, Culture and Science set a concrete target: by 2010, close to 50% of the age cohort should participate in higher education, following the targets set in the UK and Sweden. However clear the target is set, the ways to achieve it are far less specified. In the article a number of possible instruments to achieve the target are discussed and their relevance in the Dutch context is analysed. It is concluded that there are a limited number of policy instruments available. However, given the devolution of access policy to the higher education institutions and the influence of broader societal trends on participation our expectations on what government can do to reach its target need to be modest. [source]

Costs of community-based public mental health services for older adults: variations related to age and diagnosis

Todd Gilmer
Abstract Background Several studies have examined service use among older adults although, to our knowledge, none has examined costs from a systems perspective. This study examined use and costs of mental health services among older adults in San Diego County in order to determine how expenditures and modes of service varied by age cohort and psychiatric diagnosis. Methods Utilization data from San Diego County Adult and Older Adult Mental Health Services (AOAMHS) were used to identify older adults (age,,,60) receiving services in the community during fiscal year 2003,2004. Cost data were derived from detailed examination of cost reports, and Medicaid fee schedules. Trends in demographic and clinical characteristics by six age cohorts were described. Multivariate models were used to estimate the relationships between costs, age, and clinical diagnosis while controlling for other demographic and clinical characteristics. Components of costs were also examined. Results Total expenditures declined from age cohorts 60,64 through ages 85 and over. Expenditures were similar, and greatest, for clients with schizophrenia and bipolar disorder, while outlays were lower for those with major depression, other psychotic disorder, other depression, anxiety, substance use disorder, and cognitive disorders. Clients diagnosed with cognitive disorder had high use of emergency services and little connection to outpatient services. Conclusions Expenditures were related to age and clinical diagnosis. Future efforts should investigate older adults' pathways to care, and should determine whether older adults presenting in emergency services would benefit from a specialized case management program providing linkages to community based resources. Copyright 2006 John Wiley & Sons, Ltd. [source]

Impact of Recent Fracture on Health-Related Quality of Life in Postmenopausal Women,,

Susan K Brenneman PT
Abstract The effect of fractures other than hip and spine on HRQoL in younger and older women has not been extensively studied. In a cohort of 86,128 postmenopausal women, we found the impact of recent osteoporosis-related fractures on HRQoL to be similar between women <65 compared with those ,65 years of age. The impact of spine, hip, or rib fractures was greater than that of wrist fractures in both age groups. Introduction: Health-related quality of life (HRQoL) after vertebral and hip fractures has been well studied. Less is known about HRQoL after fractures at other sites. We studied the effect of recent clinical fractures on HRQoL, using Short Form-12 (SF-12). Materials and Methods: This study included 86,128 postmenopausal participants in the National Osteoporosis Risk Assessment (NORA) who responded to two follow-up surveys during a 2-year interval. At each survey, they completed the SF-12 HRQoL questionnaire and reported new fractures of the hip, spine, wrist, and rib. The effect of recent fracture on HRQoL was assessed by comparing Physical Component Score (PCS) and Mental Component Score (MCS) means for women with and without new fractures at the second survey. Analyses were by fracture type and by age group (50,64 and 65,99) and were adjusted for PCS and MCS at the first survey. Results: New fractures (320 hip, 445 vertebral, 657 rib, 835 wrist) occurring during the interval between the first and second follow-up surveys were reported by 2257 women. The PCS was poorer in both older and younger women who had fractured the hip, spine, or rib (p , 0.001). Wrist fractures had an impact on PCS in women ,65 years of age (p < 0.001), but not older women (p > 0.10). These differences in PCS by fracture status were similar to those reported for other chronic diseases such as asthma, chronic obstructive pulmonary disease (COPD), and osteoarthritis. MCS was less consistently changed by fracture status, but younger and older women with vertebral fracture (p < 0.004), older women with hip fracture (p < 0.004), and younger women with rib fracture (p < 0.004) had poorer MCS compared with those who did not fracture within their age cohort. Conclusions: Recent osteoporosis-related fractures have significant impact on HRQoL as measured by SF-12. The impact of recent fracture on HRQoL was similar for older and younger postmenopausal women. Fracture prevention and postfracture interventions that target the subsequent symptoms are needed for postmenopausal women of any age. [source]

Microparticle-associated tissue factor activity: a link between cancer and thrombosis?

Summary. Background:,Cancer, in particular mucinous adenocarcinoma, is associated with venous thromboembolism (VTE). Tissue factor (TF), initiator of coagulation, plays a central role in the paradigm that clotting and tumor growth form a vicious circle, in which hypercoagulability facilitates the aggressive biology of cancer and vice versa. Expression of TF in tumors is associated with poor differentiation and poor prognosis. Patient/methods:,We investigated the association between clinically manifest VTE and procoagulant properties of circulating microparticles (MP) isolated from blood of unselected pancreatic and breast adenocarcinoma patients' consecutive subjects, who presented with ultrasound or CT-scan confirmed VTE, and healthy subjects. Results:,Patients with disseminated breast and pancreatic cancer had significantly increased levels of MP-associated TF activity compared with healthy controls, subjects with idiopathic acute VTE and non-metastatic cancer patients. Patients with both high MP-associated TF-activity and MP-associated epithelial mucin (MUC1) had a lower survival rate at 3,9 months follow-up than those with low TF-activity and no MUC1 expression: the likelihood of survival was 0.42 (95% CI: 0.19, 0.94) for an individual with these two predictor variables present, after adjustment for other factors (age cohort, type of cancer, VTE) in the Cox proportional hazards model. Conclusions:,Our results suggest an important role for MP-associated TF and MUC1 in the pathogenesis of thrombosis in disseminated mucinous adenocarcinoma patients. Future studies should reveal the mechanism underlying the observed associations. [source]

Social structure of a polygynous tent-making bat, Cynopterus sphinx (Megachiroptera)

Jay F. Storz
Abstract The social structure of an Old World tent-making bat Cynopterus sphinx (Megachiroptera), was investigated in western India. A combination of census and mark,recapture data over 2 years (1996,98) was used to infer the form of the mating system, compositional stability of social groups and mode of new social group formation. The breeding population of C. sphinx was subdivided into diurnal roosting colonies, each of which contained one to five discrete roosting groups and often one or more solitary bats in adjacent roosts. Bats most frequently roosted in stem tents constructed in the flower/fruit clusters of the kitul palm Caryota urens. Temporal variation in social structure was assessed using visual census data for a subset of the study population over 3 years (1995,98) spanning six consecutive reproductive periods. The sex and age composition of diurnal roosting groups indicated a polygynous harem-forming mode of social organization, as groups invariably contained a single adult male, 1,37 reproductive females and their dependent young (n= 33 harems). Harem size averaged 6.1 adults in the wet season (n= 19, sd= 3.5) and 13.6 adults in the dry season (n= 14, sd= 8.5). The same harem social configuration was maintained year-round, despite a high degree of synchrony and seasonality in the timing of reproduction. Juveniles of both sexes dispersed after weaning and sexually immature bats were never present in harems at the time of parturition. Adult females often remained associated as roostmates from one parturition period to the next, and group cohesion was unaffected by turnover of harem males. Adult females frequently transferred among roosts within the same colony, and harems underwent periodic fissions and fusions. The founding of new harems most often resulted from the fissioning of previously cohesive harems within the same colony. However, some harems contained disproportionate numbers of yearling females, indicating that new groups are also founded by nulliparous females of the same age cohort. A significant degree of heterogeneity in age composition among harems was revealed in the 1998 dry season, but was unrelated to age-stratification of tent roosts. Although formation of new harems may be non-random with respect to age composition of the founders, founding events are not restricted to newly created tents and often involve recolonization of previously occupied roosts. [source]

Introduction of agriculture and its effects on women's oral health

James T. Watson
This study explores the dynamic relationship between the introduction of agriculture and its effects on women's oral health by testing the hypothesis that female reproductive physiology contributes to an oral environment more susceptible to chronic oral disease and that, in a population undergoing the foraging to farming transition, females will exhibit a higher prevalence of oral pathology than males. This is tested by comparing the presence, location, and severity of caries lesions and antemortem tooth loss across groups of reproductive aged and postreproductive females (n = 71) against corresponding groups of males (n = 71) in an Early Agricultural period (1600 B.C.,A.D. 200) skeletal sample from northwest Mexico. Caries rates did not differ by sex across age groups in the sample; however, females were found to exhibit significantly more antemortem tooth loss than males (P > 0.01). Differences were initially minimal but increased by age cohort until postreproductive females experienced a considerable amount of tooth loss, during a life stage when the accumulation of bodily insults likely contributed to dental exfoliation. Higher caries rates in females are often cited as the result of gender differences and dietary disparities in agricultural communities. In an early farming community, with diets being relatively equal, women were found to experience similar caries expression but greater tooth loss. We believe this differential pattern of oral pathology provides new evidence in support of theinterpretation that women's oral health is impacted by effects relating to reproductive biology. Am. J. Hum. Biol. 2010. 2009 Wiley-Liss, Inc. [source]

The Relationship between Personal Income and Net Worth in Australia

John Creedy
This article uses data from the Household, Income and Labour Dynamics in Australia (HILDA) Survey to examine the changing distribution of net worth with age. Even after controlling for age, the relationship between income and net worth is positive, except for the older age groups. Inequality falls as age increases. The income poor save in different forms compared with high income individuals of the same age cohort. Holdings of financial assets, especially equity investments and superannuation, are heavily concentrated in the hands of high income earners, while fixed income investments are favoured by the elderly for all income groups. [source]


Bradley Bowden
child labour; demographic economics; history; labour demand; Queensland This article explores the extent and significance of child and youth work in late 19th century Australia. It demonstrates that, while demographic changes meant that almost half the population was aged 19 years or less, this age cohort never comprised more than 18 per cent of the recorded workforce. It is argued that this under-representation reflects the fact that children and youths were ill-suited to the work demands of most colonial occupations. They did not threaten the position of adult males in the key areas of the economy such as construction, heavy engineering, pastoral work, mining and transport. [source]

Relation between vascular risk factors and cognition at age 75

P. Fischer
Objective ,, Recent trends in dementia research emphasize that not only cerebrovascular events but also vascular risk factors induce, favour or cause cognitive impairment and Alzheimer's disease. Material and methods ,, We evaluated vascular risk factors (blood pressure, LDL cholesterol, HDL cholesterol, triglycerides, HbA1c, homocysteine, lipoprotein(a), fibrinogen, C-reactive protein and smoking habits) in a community-based cohort of 75-year-old individuals of two districts in Vienna (247 men, 359 women) and correlated these risk factors with overall cognition. Results ,, Pathological vascular risk factors were found frequently in the age cohort. However, the expected associations between the Mini-Mental State Examination and any cardiovascular risk factors were missing. Only individuals with a positive history of smoking showed lower cognitive capacities. Conclusions ,, We assume that cognitive dysfunction in old age is connected to factors other than the known classical and novel risk factors for the development of cardiovascular disease. [source]

A Place Where I Can Let My Hair Down: from social club to cultural center in an urban Indian community

CITY & SOCIETY, Issue 1 2001
Deborah Davis Jackson
The "Riverton" Indian Center was established in the 1950s as large numbers of Native Americans migrated to the city from reservations around the Great Lakes and beyond, and underwent significant changes throughout the second half of the twentieth century. These changes, and the conflicts that resulted from them, were shaped by far larger political,economic and cultural forces: on the one hand, River ton's economy, along with the economies of many midsized cities in the Great Lakes region,was undergoing rapid deindustrialization with devastating consequences to local residents, including American Indians; on the other hand, social and cultural changes in the U.S., starting in the 1960s, made Native Americans,or at least a romanticized image of Native Americans,increasingly popular with non-Natives. These forces converged to create the three distinct phases in the Riverton Indian Center's history, each associated with a particular age cohort,a trajectory that might well be typical of deindustrializing cities in the Great Lakes region. [American Indians; community and identity; deindistrialivng cities; Upper Great Lakes region] [source]

On intimacy, sexual activities and exposure to sexual abuse among children and adolescents with mobility impairment

L Jemt
Abstract Aim: The aim was to describe experiences of intimacy and sexual activity and exposure to sexual abuse among children and adolescents with mobility impairment, and to relate these experiences to socio-demographic data, disability characteristics and well-being. Methods: This study included semi-structured interviews with 141 children and adolescents aged 7,18 years with mobility impairment. Interpersonal experiences of intimacy and sexuality, socio-demographic data, disability characteristics and well-being were registered. Results: About half of the children and adolescents in the study had been in a boy- or a girlfriend relationship, and about a fifth had an ongoing relationship. Of the adolescents, 15% had at least one experience of a sexual relationship. Whereas no particular sexual dysfunction was reported, 15% had concerns about their future sexual activities, presumably related to mobility impairment. A history of sexual abuse was reported by 7% in the age cohort of 13,18 years. The socio-demographic and disability-related features had a marginal influence on the experiences of intimacy and sexual activities. Conclusion: Several aspects of sexual health are not fully realized for children and adolescents with impaired mobility, and there is a need for specialized sexual health care services to protect the sexual rights of this group. [source]


CRIMINOLOGY, Issue 4 2005
The aim of this paper is to describe the development of criminal behavior from early adolescence to late adulthood based on conviction data for a sample of Dutch offenders. Measuring over an age span of 12 to 72, we ask whether there is evidence for (1) criminal trajectories that are distinct in terms of time path, (2) a small group of persistent offenders, (3) criminal trajectories that are distinct in the mix of crimes committed, or, more specifically, persistent offenders disproportionately engaging in violent offences, and (4) different offender groups having different social profiles in life domains other than crime. The analysis is based on the conviction histories of the Dutch offenders in the Criminal Career and Life Course Study. Four trajectory groups were identified using a semi-parametric, group-based model: sporadic offenders, low-rate desisters, moderate-rate desisters and high-rate persisters. Analyses show that high-rate persisters engage in crime at a very substantial rate, even after age 50. Compared to other trajectory groups the high-rate persistent trajectory group disproportionately engages in property crimes rather than violent crimes. Also, these distinct trajectories are found to be remarkably similar across age cohorts. [source]

Iron status in Danish men 1984,94: a cohort comparison of changes in iron stores and the prevalence of iron deficiency and iron overload

Nils Milman
Abstract:,Background and objectives : From 1954 to 1987, flour in Denmark was fortified with 30 mg carbonyl iron per kg. This mandatory fortification was abolished in 1987. The aim of this study was to compare iron status in Danish men before and after abolition of iron fortification. Methods : Iron status (serum ferritin, haemoglobin), was assessed in population surveys in Copenhagen County during 1983,84 comprising 1324 Caucasian men (1024 non-blood-donors, 300 blood donors) and in 1993,94 comprising 1288 Caucasian men (1103 non-blood-donors, 185 donors), equally distributed in age cohorts of 40, 50, 60 and 70 yr. Results : In the 1984 survey median serum ferritin values in the four age cohorts in non-blood-donors were 136, 141, 133 and 111 g/L, and in the 1994 survey 177, 173, 186 and 148 g L ,1 , respectively. The difference was significant in all age groups ( P <0.001). There was no significant difference between the two surveys concerning the prevalence of small iron stores (ferritin 16,32 g L ,1 ), depleted iron stores (ferritin <16 g L ,1 ) or iron-deficiency anaemia (ferritin <13 g L ,1 and Hb <5th percentile for iron-replete men). However, from 1984 to 1994, the prevalence of iron overload (ferritin >300 g L ,1 ) increased from 11.3% to 18.9% ( P <0.0001). During the study period there was an increase in body mass index ( P <0.0001), alcohol consumption ( P <0.03) and use of non-steroid anti-inflammatory drugs (NSAID) ( P <0.0001), and a decrease in the use of vitamin,mineral supplements ( P <0.04) and in the prevalence of tobacco smoking ( P <0.0001). In contrast, median ferritin in blood donors showed a significant fall from 1984 to 1994 (103 vs. 74 g L ,1 , P <0.02). Conclusion : Abolition of iron fortification reduced the iron content of the Danish diet by an average of 0.24 mg MJ ,1 , and the median dietary iron intake in men from 17 to 12 mg d ,1 . From 1984 to 1994, body iron stores and the prevalence of iron overload in Danish men increased significantly, despite the abolition of food iron fortification. The reason appears to be changes in dietary habits, with a lower consumption of dairy products and eggs, which inhibit iron absorption, and a higher consumption of alcohol, meat, and poultry, containing haem iron and enhancing iron absorption. The high prevalence of iron overload in men may constitute a health risk. [source]

Factors influencing the caries decline in Lithuanian adolescents , trends in the period 1993,2001

Jolanta Aleksej
The study aimed to relate a number of factors to the numbers of decayed, missing and filled teeth (DMFT) in 12- and 15-yr-olds examined and interviewed in 1993 and 2001. A total of 1250 children in 1993 and 935 in 2001 were clinically examined and completed a detailed questionnaire on dental health-related topics. Factors were related to the DMFT count applying multiple regression analysis. From 1993 to 2001, the mean DMFT decreased approximately 30% in both age cohorts. Despite an observed improvement in dental health in Lithuanian children, the number of Lithuanian children reporting frequent sugar consumption, brushing teeth irregularly and visiting the dentist only in case of emergency was still high compared with Western countries. The DMFT values were related to the fluoride content in the drinking water, oral hygiene, residency and year of examination. [source]

Change in Paternal Involvement from 1977 to 1997: A Cohort Analysis

Scott S. Hall
Contemporary social expectations of fathering promote an image of fathers more heavily involved in child rearing than their counterparts from past decades. However, some have questioned whether or not the actual "conduct" of fatherhood has changed over time. Fathers from two nationally representative data sets and from two distinct time periods,1977 and 1997,were selected to test whether there has been a change in the amount of time that fathers spend with their children. The results of a cohort analysis indicated that fathers from each of the age cohorts in 1997 reported spending more time with children on both workdays and non-workdays than comparable fathers in 1977. In addition, younger fathers from both time periods generally reported spending more time with their children than did older fathers. Common predictors of paternal involvement differed somewhat in each time period. [source]

Ageing and the tax implied in public pension schemes: simulations for selected OECD countries

FISCAL STUDIES, Issue 2 2004
Robert Fenge
Abstract A key figure suited to measuring intergenerational imbalances in unfunded public pension schemes is given by the ,implicit tax rate' imposed on each generation's lifetime income. The implicit tax arises from the fact that, quite generally, pension benefits fall short of actuarial returns to contributions paid to these systems while actively working. Under current pension policies, implicit tax rates will increase sharply for younger generations in most industrialised countries. In this paper, this is illustrated for the cases of France, Germany, Italy, Japan, Sweden, the UK and the USA. Nevertheless, there are remarkable differences across countries regarding both the level of implicit taxes and their development over successive age cohorts, which can be attributed to differences in ageing processes and in the institutional features of national pension systems. In addition, we can demonstrate how effective different approaches to pension reform are in smoothing the intergenerational profile of implicit tax rates. [source]

The effect of service quality on trust and commitment varying across generations

Jinsook E. Cho
Abstract We examine the effect of service quality on consumer trust and commitment in the context of obtaining a financial loan and how these relationships vary across different generational cohorts. We find that the service quality offered by a loan officer has a significant effect on consumer trust towards a financial institution, which in turn influences consumer commitment to a financial institution for a future transaction. We also find that relative strengths of a few paths in the model differ across different age cohorts, indicating some generational variability in the relationship between service quality, trust and commitment. [source]

Costs of community-based public mental health services for older adults: variations related to age and diagnosis

Todd Gilmer
Abstract Background Several studies have examined service use among older adults although, to our knowledge, none has examined costs from a systems perspective. This study examined use and costs of mental health services among older adults in San Diego County in order to determine how expenditures and modes of service varied by age cohort and psychiatric diagnosis. Methods Utilization data from San Diego County Adult and Older Adult Mental Health Services (AOAMHS) were used to identify older adults (age,,,60) receiving services in the community during fiscal year 2003,2004. Cost data were derived from detailed examination of cost reports, and Medicaid fee schedules. Trends in demographic and clinical characteristics by six age cohorts were described. Multivariate models were used to estimate the relationships between costs, age, and clinical diagnosis while controlling for other demographic and clinical characteristics. Components of costs were also examined. Results Total expenditures declined from age cohorts 60,64 through ages 85 and over. Expenditures were similar, and greatest, for clients with schizophrenia and bipolar disorder, while outlays were lower for those with major depression, other psychotic disorder, other depression, anxiety, substance use disorder, and cognitive disorders. Clients diagnosed with cognitive disorder had high use of emergency services and little connection to outpatient services. Conclusions Expenditures were related to age and clinical diagnosis. Future efforts should investigate older adults' pathways to care, and should determine whether older adults presenting in emergency services would benefit from a specialized case management program providing linkages to community based resources. Copyright 2006 John Wiley & Sons, Ltd. [source]

Feasible Model for Prevention of Functional Decline in Older People: Municipality-Randomized, Controlled Trial

Mikkel Vass MD
Objectives: To investigate the effect of an educational program for preventive healthcare professionals in routine primary care on functional ability, nursing home admissions, and mortality in older adults. Design: A prospective, controlled 3-year follow-up study (1999,2001) in primary care with randomization and intervention at the municipality level and outcomes measured at the individual level in two age cohorts. Setting: Primary care. Participants: Of 81 eligible municipalities in four counties, 34 agreed to participate. A total study population of 5,788 home-dwelling subjects aged 75 and 80 were asked to participate. Written consent was obtained from 4,060 persons (70.1%), of whom 2,104 were living in 17 intervention municipalities and 1,956 were living in 17 matched control municipalities. Intervention: Intervention municipality visitors received ongoing education, and local general practitioners were introduced to a short geriatric assessment program early in the study period. Control municipalities visitors and general practitioners received no education. Measurements: At the 3-year follow-up, the outcome measures of mortality and nursing home admissions were obtained from all, and the outcome measure of functional ability was obtained from 3,383 (95.6%) of 3,540 surviving participants. Results: Education improved functional ability (odds ratio=1.20, 95% confidence interval (CI)=1.01,1.42, P=.04) in intervention municipality participants, notably in the 80-year-olds. There were no differences in mortality (relative risk (RR)=1.06, 95% CI=0.87,1.28, P=.59) or rates of nursing home admissions after 3 years (RR=0.74, 95% CI=0.50,1.09, P=.13). Subjects aged 80 benefited from accepting and receiving in-home assessment with regular follow-ups. Conclusion: A brief, feasible educational program for primary care professionals helps preserve older people's functional ability. [source]

Bullying in school and adolescent sense of empowerment: an analysis of relationships with parents, friends, and teachers,

Maury Nation
Abstract We explore the development of bullying and victimization in school by investigating 11-, 13- and 15-year-olds' sense of interpersonal empowerment with parents, friends and teachers. A national sample of 4386 male and female students from 243 middle and secondary schools in Italy were surveyed. Boys were more likely than girls to be bullies and more likely to have been a bully/victim. Victimization and the likelihood of being both a bully and a victim declined with age. Bullying increased with age among boys whereas for girls it was slightly more prevalent at age 13 than ages 11 or 15. The sense of empowerment students experience with their teachers decreased in the older cohorts. Disempowered relationships with teachers consistently predicted bullying behaviour. Higher social competence was reported by 13- and 15-year-old bullies. Chronically bullied students had lower social competence in all age cohorts. Otherwise, predictors of victimization varied by age: 11-year-old victims felt less empowered by their teachers; 15-year-old victims reported more difficulties in negotiating cooperative relationships with parents. Bullies in all cohorts and younger bully/victims feel less empowered by their teachers. These findings suggest that students who are disempowered by teachers may either compensate by oppressing (bullying) peers or generalize the power differential with peers (become a victim). Copyright 2007 John Wiley & Sons, Ltd. [source]

Behavioural thermoregulation in two freshwater fish species

A. J. W. Ward
In the presence of a vertical thermal gradient, juvenile three-spined sticklebacks Gasterosteus aculeatus and minnows Phoxinus phoxinus positioned themselves higher in the water column compared with adult conspecifics. This result was consistent regardless of whether age cohorts were tested separately or together. Furthermore, juveniles but not adult fishes positioned themselves higher in water column in the presence of a thermal gradient compared with those in the absence of a thermal gradient. Juvenile G. aculeatus and adult fish of both species did opt to position themselves higher in the water column in the hours immediately following a feeding event relative to their positions in the same gradient when they had not fed. [source]

Drinks of the Father: Father's Maximum Number of Drinks Consumed Predicts Externalizing Disorders, Substance Use, and Substance Use Disorders in Preadolescent and Adolescent Offspring

ALCOHOLISM, Issue 12 2002
Stephen M. Malone
Background The maximum number of drinks consumed in 24 hr seems to be an interesting phenotype related to alcoholism. The goal of the present study was to determine in an epidemiologic sample whether this measure of drinking history in fathers predicted externalizing behavioral disorders, substance use, and substance abuse in preadolescent and adolescent offspring and whether any such associations would be independent of paternal alcohol dependence diagnoses. Methods Subjects were male and female twins from both age cohorts of the Minnesota Twin Family Study, a population-based longitudinal study, and were approximately 11 or 17 years of age, respectively, upon study enrollment. In both age cohorts, diagnoses of conduct disorder, oppositional defiant disorder, and attention-deficit/hyperactivity disorder served as outcome measures. In addition, measures of lifetime substance use and of the presence of symptoms of substance abuse were derived for the 11-year-old cohort when subjects were approximately 14 years old and diagnoses of substance abuse were derived for the older cohort at age 17. An extension of logistic regression using generalized estimating equations served to assess whether paternal maximum alcohol consumption predicted filial outcome measures. Results Paternal maximum alcohol consumption was consistently associated with conduct disorder, substance use, and substance abuse or dependence in male and female offspring. These associations were not mediated by a primary effect of paternal alcoholism. Conclusions Paternal maximum alcohol consumption was uniquely associated with those offspring characteristics most reliably found in adolescent children of alcoholic parents. This phenotype might supplement DSM diagnoses of alcohol dependence to reduce the number of false positives in genetic research. [source]

Error rate on the antisaccade task: Heritability and developmental change in performance among preadolescent and late-adolescent female twin youth

Stephen M. Malone
We examined heritability of error rate on the antisaccade task among female twin youths. This task appears to be sensitive to prefrontal functioning, providing a measure of individual differences in inhibitory control associated with genetic risk for schizophrenia. The sample consisted of 674 11-year-olds and 616 17-year-olds, comprising the two cohorts of female twins from the Minnesota Twin Family Study, a population-based investigation of substance abuse and related psychopathology. We used biometric model-fitting methods to determine the relative magnitude of genetic and environmental influences on performance. In both age cohorts, the best fitting model contained additive genes and nonshared environment. Despite substantial age-related differences in mean performance levels (effect size = .81), additive genes accounted for greater than half the variance in performance in both age cohorts. These results are consistent with the hypothesis that antisaccade error rate might serve as an endophenotype for behavior disorders reflecting frontal lobe dysfunction or problems with inhibitory control. [source]

Heritability of different measures of smooth pursuit eye tracking dysfunction: A study of normal twins

Joanna Katsanis
Research studies have found that smooth pursuit eye movement dysfunction may serve as an index of genetic liability to develop schizophrenia. The heritability of various measures of smooth pursuit eye tracking proficiency and the saccades that occur during smooth pursuit was examined in 64 monozygotic (MZ) and 48 dizygotic (DZ) twin pairs. Two age cohorts were assessed (11,12 and 17,18 years of age). Intraclass correlations indicated significant similarity in the MZ twins for almost all measures in both age cohorts, whereas few of the DZ twin correlations attained significance. Biometrical modeling indicated that genetic mechanisms influence performance on both global and specific eye tracking measures, accounting for about 40% to 60% of the variance. These findings suggest that the underlying brain systems responsible for smooth pursuit and saccade generation during pursuit are under partial genetic control. [source]

Genetic characterization of specific pathogen-free rhesus macaque (Macaca mulatta) populations at the California National Primate Research Center (CNPRC)

Sree Kanthaswamy
Abstract A study based on 14 STRs was conducted to understand intergenerational genetic changes that have occurred within the California National Primate Research Center's (CNPRC) regular specific pathogen-free (SPF) and super-SPF captive rhesus macaque populations relative to their conventional founders. Intergenerational genetic drift has caused age cohorts of each study population, especially within the conventional population, to become increasingly differentiated from each other and from their founders. Although there is still only minimal stratification between the conventional population and either of the two SPF populations, separate derivation of the regular and super-SPF animals from their conventional founders has caused the two SPF populations to remain marginally different from each other. The regular SPF and, especially, the super-SPF populations have been influenced by the effects of differential ancestry, sampling, and lost rare alleles, causing a substantial degree of genetic divergence between these subpopulations. The country of origin of founders is the principal determinant of the MHC haplotype composition of the SPF stocks at the CNPRC. Selection of SPF colony breeders bearing desired genotypes of Mamu-A*01 or -B*01 has not affected the overall genetic heterogeneity of the conventional and the SPF research stocks. Because misclassifying the ancestry of research stocks can undermine experimental outcomes by excluding animals with regional-specific genotypes or phenotypes of importance, understanding founder/descendent genetic relationships is crucial for investigating candidate genes with distinct geographic origins. Together with demographic management, population genetic assessments of SPF colonies can curtail excessive phenotypic variation among the study stocks and facilitate successful production goals. Am. J. Primatol. 72:587,599, 2010. 2010 Wiley-Liss, Inc. [source]

ORIGINAL RESEARCH,EPIDEMIOLOGY: Sexual Desire in a Nationally Representative Danish Population

Lene Eplov MD
ABSTRACT Introduction., There are only a few studies on the frequency of sexual desire in the general population, whereas studies investigating the frequency of disordered sexual desire are more common. Aim., The aim of this study was to describe the frequency of sexual desire in a representative sample of the adult Danish population and to analyze the relationships between a number of relevant variables and sexual desire. Methods., The study population (N = 10,458, response rate 84.8%) answered a questionnaire with questions on sexual matters. The representativity of the population was examined. The frequency of self-reported sexual desire and decrease in sexual desire over a 5-year period was calculated for the two genders across age cohorts. Multiple logistic regression analysis was used to analyze the relationship between potential determinants and sexual desire. Main Outcome Measures., The frequency of self-reported sexual desire and decrease in sexual desire was examined. Factors of importance for sexual desire were tested using two outcome measures: (i) often having sexual desire; and (ii) seldom having sexual desire. Results., A significant association between gender and sexual desire was found in all age groups, as men had a significantly higher level of sexual desire than women. In both genders, the frequency of sexual desire was significantly reduced with increasing age. Among the 45- to 66-year-olds, 57% of the men and 47% of the women reported no change in the level of sexual desire over the past 5 years. In general terms, factors related to seldom having sexual desire were age and social, psychological, and physical distress in both genders. Conclusion., This study shows that overall, men have a higher level of sexual desire than women; sexual desire decreases with increasing age; and social, psychological, or physical distress are associated with low level of sexual desire in both genders. Eplov L, Giraldi A, Davidsen M, Garde K, and Kamper-Jrgensen F. Sexual desire in a nationally representative Danish population. J Sex Med 2007;4:47,56. [source]

Paranasal Sinus Development: A Radiographic Study,

Rahul K. Shah MD
Abstract Objective To demonstrate the development of the paranasal sinuses in a pediatric population by computed tomography scans. Study Design Radiology records at a tertiary care institution were reviewed for the computed tomography scans of the face, orbit, or paranasal sinuses in patients aged 0 to 12 years. Methods Computed tomography scans were reviewed by a head and neck radiologist and otolaryngologist for the development of the frontal, maxillary, ethmoid, and sphenoid sinuses. The size of the pneumatized paranasal sinuses was measured in two planes and graded on a scale of 0 to 3. Ossification of the maxillary crest and vomer, obliteration of the foramen cecum, and development of agger nasi cells, Haller cells, and the superior turbinate were studied. Patients with syndromes, nasal stenosis, choanal atresia, or cystic fibrosis were excluded from the study. Results In all, 91 computed tomography scans in 66 patients were studied. Serial development could be followed in 16 patients who underwent repeat scans. Patients were divided into six age cohorts based on their age at the time of the scan: 0 to 3 months (10%), 3 to 12 months (13%), 1 to 3 years (13%), 3 to 5 years (20%), 5 to 8 years (29%), and 8 to 12 years (16%). Ethmoid sinuses were the first to fully develop, followed sequentially by maxillary, sphenoid, and frontal sinuses. Each sinus has a rapid rate of development during specified age cohorts. Conclusion The results will aid the physician when correlating the clinical and radiographic findings of pediatric patients aged 0 to 12 years who are being evaluated for sinus disease and potential surgical intervention. [source]

Attrition in longitudinal studies: who do you lose?

Anne F. Young
Objective: To describe the risk factors for various types of attrition in three age cohorts of women in a longitudinal study and to discuss strategies to minimise attrition. Methods: Analysis of survey data from the Australian Longitudinal Study on Women's Health, collected by mailed questionnaire. In 1996, the study recruited and surveyed a national random sample of ,younger' (18,23 years, n=14,247), ,mid-age' (45,50 years, n=13,716), and ,older' women (70,75 years, n=12,432), and began a staggered cycle of mailed follow-up questionnaires: 1998 (mid-age), 1999 (older), 2000 (younger) and so on. Demographic, health and social risk factors for attrition were examined using multivariate analysis. Results: Attrition at survey 2 was highest among younger women (32%), mainly because of participants not being contactable (21%), and lower among the older (16%) and mid-age women (10%). At survey 1, the survey 2 non-respondents were more likely to report having less education, being born in a non-English-speaking country and being a current smoker, in all cohorts, and had poorer health (mid-age and older cohort) and more diffculty managing on their income (younger and mid-age). Conclusion: Although the magnitude of different types of attrition was found to differ by age, there were several risk factors for attrition that remained consistent. These fndings are important to inform future studies on ways to lessen or prevent systematic loss of participants. Implications: Recruitment and follow-up methods in longitudinal studies should be tailored to maximise retention of participants at higher risk of dropout. [source]


Jeffrey G. Williamson
This lecture explores the connection between demographic transitions, mass migrations and international capital flows. It reviews how demographic transitions influence the size of age cohorts, and then how these changes in age distribution influence excess demands in receiving regions and excess supplies in sending regions. The lecture offers four examples , two from the first global century and two from the second global century , where shocks generated by demographic transitions have had an enormous impact on factor flows: European mass migrations to the New World before 1914; African mass migrations to the OECD over the past two decades; British capital export to the New World before 1914; and capital flows across East Asian borders after 1950 and before the melt down of the 1990s. The lecture concludes with an assessment of the demographic contribution to the East Asian miracle (and slowdown) over the past half century. [source]