WorldWideScience

Sample records for black-white population longitudinal

  1. Bogalusa Heart Study: a long-term community study of a rural biracial (Black/White) population.

    Science.gov (United States)

    Berenson, G S

    2001-11-01

    The Bogalusa Heart Study, a long-term population study with a continued relationship with a community, addresses the problem of capacity building in minority health research. The study was originally funded as a Specialized Center of Research-Arteriosclerosis (SCOR-A) by the National Heart Lung and Blood Institute (NHLBI). These centers were to conduct research on atherosclerosis, coronary artery disease (CAD), hypertension, diabetes mellitus, and complications of cardiovascular-renal disease as the major causes of deaths in the United States. From earlier research on atherosclerosis, we became interested in the underlying characteristics in early life that would eventually lead to clinical morbidity and mortality from heart disease. An observation at autopsy showed the degree of atherosclerotic involvement in human aortas, from young to older individuals (Figure 1). For example, at age 40 years, marked individual variability occurred in the severity and involvement with atherosclerotic disease. Some individuals showed very little disease, while almost 70% of the surface was diseased in others. Further studies on arterial wall matrix showed aortas from young individuals varied with the extent of disease and its chemical composition. This background stimulated an interest in studying children for early clinical evidence of major adult heart diseases. The Bogalusa Heart Study was begun in 1972 as an epidemiology study of cardiovascular risk factors in children and adolescents; it eventually evolved into observations of young adults. Bogalusa, LA, is a biracial (black/white) rural community 70 miles north of New Orleans, comparable to many other communities in southeastern United States.

  2. Converging Employment Patterns of Black, White, and Hispanic Women: Return to Work after First Birth.

    Science.gov (United States)

    Yoon, Young-Hee; Waite, Linda J.

    1994-01-01

    Examined determinants of women's return to work following birth of first child among black, white, and Mexican-origin women to test hypothesis that previous racial differentials in employment of new mothers observed during 1960s and 1970s have disappeared with changes in overall employment patterns of women. Data from National Longitudinal Survey…

  3. Educational Achievement and Black-White Inequality. Statistical Analysis Report.

    Science.gov (United States)

    Jacobson, Jonathan; Olsen, Cara; Rice, Jennifer King; Sweetland, Stephen

    This study explored relationships between black-white differences in educational achievement and black-white differences in various educational and economic outcomes. Three data sets examined the extent to which black-white differences in labor market outcomes, in educational attainment, and in mathematics and reading achievement were present for…

  4. Explaining the black-white gap in cognitive test scores: Toward a theory of adverse impact.

    Science.gov (United States)

    Cottrell, Jonathan M; Newman, Daniel A; Roisman, Glenn I

    2015-11-01

    In understanding the causes of adverse impact, a key parameter is the Black-White difference in cognitive test scores. To advance theory on why Black-White cognitive ability/knowledge test score gaps exist, and on how these gaps develop over time, the current article proposes an inductive explanatory model derived from past empirical findings. According to this theoretical model, Black-White group mean differences in cognitive test scores arise from the following racially disparate conditions: family income, maternal education, maternal verbal ability/knowledge, learning materials in the home, parenting factors (maternal sensitivity, maternal warmth and acceptance, and safe physical environment), child birth order, and child birth weight. Results from a 5-wave longitudinal growth model estimated on children in the NICHD Study of Early Child Care and Youth Development from ages 4 through 15 years show significant Black-White cognitive test score gaps throughout early development that did not grow significantly over time (i.e., significant intercept differences, but not slope differences). Importantly, the racially disparate conditions listed above can account for the relation between race and cognitive test scores. We propose a parsimonious 3-Step Model that explains how cognitive test score gaps arise, in which race relates to maternal disadvantage, which in turn relates to parenting factors, which in turn relate to cognitive test scores. This model and results offer to fill a need for theory on the etiology of the Black-White ethnic group gap in cognitive test scores, and attempt to address a missing link in the theory of adverse impact. PMID:25867168

  5. Education and black-white interracial marriage.

    Science.gov (United States)

    Gullickson, Aaron

    2006-11-01

    This article examines competing theoretical claims regarding how an individual's education will affect his or her likelihood of interracial marriage. I demonstrate that prior models of interracial marriage have failed to adequately distinguish the joint and marginal effects of education on interracial marriage and present a model capable of distinguishing these effects. I test this model on black-white interracial marriages using 1980, 1990, and 2000 U.S. census data. The results reveal partial support for status exchange theory within black male-white female unions and strong isolation of lower-class blacks from the interracial marriage market. Structural assimilation theory is not supported because the educational attainment of whites is not related in any consistent fashion to the likelihood of interracial marriage. The strong isolation of lower-class blacks from the interracial marriage market has gone unnoticed in prior research because of the failure of prior methods to distinguish joint and marginal effects.

  6. An examination of black/white differences in the rate of age-related mortality increase

    Directory of Open Access Journals (Sweden)

    Andrew Fenelon

    2013-09-01

    Full Text Available BACKGROUND The rate of mortality increase with age among adults is typically used as a measure of the rate of functional decline associated with aging or senescence. While black and white populations differ in the level of mortality, mortality also rises less rapidly with age for blacks than for whites, leading to the well-known black/white mortality "crossover". OBJECTIVE This paper investigates black/white differences in the rate of mortality increase with age for major causes of death in order to examine the factors responsible for the black/white crossover. METHODS The analysis considers two explanations for the crossover: selective survival and age misreporting. Mortality is modeled using a Gompertz model for 11 causes of death from ages 50-84 among blacks and whites by sex. RESULTS Mortality increases more rapidly with age for whites than for blacks for nearly all causes of death considered. The all-cause mortality rate of mortality increase is nearly two percentage points higher for whites. The analysis finds evidence for both selective survival and age misreporting, although age misreporting is a more prominent explanation among women. CONCLUSIONS The black/white mortality crossover reflects large differences in the rate of age-related mortality increase. Instead of reflecting the impact of specific causes of death, this pattern exists across many disparate disease conditions, indicating the need for a broad explanation.

  7. Black-White Health Inequalities in Canada.

    Science.gov (United States)

    Veenstra, Gerry; Patterson, Andrew C

    2016-02-01

    Little is known about Black-White health inequalities in Canada or the applicability of competing explanations for them. To address this gap, we used nine cycles of the Canadian Community Health Survey to analyze multiple health outcomes in a sample of 3,127 Black women, 309,720 White women, 2,529 Black men and 250,511 White men. Adjusting for age, marital status, urban/rural residence and immigrant status, Black women and men were more likely than their White counterparts to report diabetes and hypertension, Black women were less likely than White women to report cancer and fair/poor mental health and Black men were less likely than White men to report heart disease. These health inequalities persisted after controlling for education, household income, smoking, physical activity and body-mass index. We conclude that high rates of diabetes and hypertension among Black Canadians may stem from experiences of racism in everyday life, low rates of heart disease and cancer among Black Canadians may reflect survival bias and low rates of fair/poor mental health among Black Canadian women represent a mental health paradox similar to the one that exists for African Americans in the United States. PMID:25894533

  8. Inside Interracial Marriages: Accounts of Black-White Couples

    OpenAIRE

    Donnell, Angela S.

    1998-01-01

    INSIDE INTERRACIAL MARRIAGES: ACCOUNTD OF BLACK-WHITE COUPLES By Angela S. Donnell (ABSTRACT) The purpose of this qualitative study was to investigate the chronic daily concerns that eight self-identified Black-White interracial couples described as stressful and to identify the coping strategies that they utilized to reduce feelings of distress. Another goal of this study was to discover the actions that these eight couples took to maintain marital satisfaction. This in...

  9. The Black-White Test Score Gap Through Third Grade

    OpenAIRE

    Roland G. Fryer; Levitt, Steven D.

    2005-01-01

    This paper describes basic facts regarding the black-white test score gap over the first four years of school. Black children enter school substantially behind their white counterparts in reading and math, but including a small number of covariates erases the gap. Over the first four years of school, however, blacks lose substantial ground relative to other races; averaging .10 standard deviations per school year. By the end of third grade there is a large Black-White test score gap that cann...

  10. The Black-White achievement gap: Do state policies matter?

    Directory of Open Access Journals (Sweden)

    Henry I. Braun

    2006-03-01

    Full Text Available A longstanding issue in American education is the gap in academic achievement between majority and minority students. The goal of this study is to accumulate and evaluate evidence on the relationship between state education policies and changes in the Black-White achievement gap, while addressing some of the methodological issues that have led to differences in interpretations of earlier findings. To that end, we consider the experiences of ten states that together enroll more than forty percent of the nation's Black students. We estimate the trajectories of Black student and White student achievement on the NAEP 8th grade mathematics assessment over the period 1992 to 2000, and examine the achievement gap at three levels of aggregation: the state as a whole, groups of schools (strata within a state defined by the SES level of the student population, and within schools within a stratum within a state. From 1992 to 2000, at every level of aggregation, mean achievement rose for both Black students and White students. However, for most states the achievement gaps were large and changed very little at every level of aggregation. The gaps are pervasive, profound and persistent. There is substantial heterogeneity among states in the types of policies they pursued, as well as the coherence and consistency of those policies during the period 1988-1998. We find that states' overall policy rankings (based on our review of the data correlate moderately with their record in improving Black student achievement but are somewhat less useful in predicting their record with respect to reducing the achievement gaps. States' rankings on commitment to teacher quality correlate almost as well as did the overall policy ranking. Thus, state reform efforts are a blunt tool, but a tool nonetheless. Our findings are consistent with the following recommendations: states' reform efforts should be built on broad-based support and buffered as much as possible from changes in

  11. Black- White Differences in Predictive Validity of Depressive Symptoms for Subsequent Major Depression

    Directory of Open Access Journals (Sweden)

    Ehsan eMoazen Zadeh

    2016-02-01

    Full Text Available BackgroundBlack- White differences are shown in psychosocial and medical correlates of depressive symptoms and major depressive disorder (MDD. The current longitudinal study compared Blacks and Whites for the association between baseline depressive symptoms and subsequent risk of MDD 15 years later. MethodsData came from the Americans’ Changing Lives (ACL Study that followed 3,361 individuals (2,205 Whites and 1,156 Blacks from 1986 to 2001. Predictor was baseline depressive symptoms measured using an 11-item Center for Epidemiological Studies-Depression (CES-D in 1986. Outcome was 12 month MDD measured using the Composite International Diagnostic Interview (CIDI at 2001. Covariates included baseline socio-demographics, financial difficulty, chronic medical conditions, and self-rated health (SRH measured at 1986. We used logistic regression to evaluate the association between baseline CES-D score and CIDI-based MDD 15 years later net of demographics, SES, CMCs and SRH. The models were applied in the pooled sample, as well as Blacks and Whites. We also reported data on reliability and factor structure of CES-D based on ethnicity. ResultsAccording to the logistic regression models, baseline CES-D scores were predictive of subsequent CIDI- based 12 month MDD 15 years later among Whites but not Blacks. Ethnic differences in predictive validity of CES-D scores on MDD could not be attributed to the ethnic differences in reliability of the CES-D which was even higher for Blacks than Whites. ConclusionBlack–White differences exist in the association between baseline depressive symptoms and subsequent risk of MDD over 15 years. Ethnic differences in the longitudinal link between baseline CES-D and subsequent risk of MDD among Blacks may explain some of the Black - White differences in social, psychological, and medical correlates of depressive symptoms and depression. Future research is still needed to compare Blacks and Whites for confirmatory

  12. The Measured Black-White Wage Gap among Women Is Too Small

    OpenAIRE

    Derek Neal

    2004-01-01

    Taken as a whole, the literature on black-white wage inequality suggests that racial gaps in potential wages are much larger among men than women, and further that one can accurately assess black-white gaps in potential wages among women without accounting for black-white differences in patterns of female labor supply. This paper challenges both pieces of this conventional wisdom. I provide several estimates of the black-white gap in potential wages for the year 1990 using data from the Natio...

  13. Spironolactone use and renal toxicity: population based longitudinal analysis.

    OpenAIRE

    Wei, L; Struthers, A D; Fahey, T; Watson, A D; MacDonald, T. M.

    2010-01-01

    Objective To determine the safety of spironolactone prescribing in the setting of the UK National Health Service. Design Population based longitudinal analysis using a record linkage database. Setting Tayside, Scotland. Population All patients who received one or more dispensed prescriptions for spironolactone between 1994 and 2007. Main outcome measures Rates of prescribing for spironolactone, hospital admissions for hyperkalaemia, and hyperkalaemia and renal function without...

  14. Explaining Black-White Disparity in Maltreatment: Poverty, Female-Headed Families, and Urbanization

    Science.gov (United States)

    Schuck, Amie M.

    2005-01-01

    The purpose of the current study was to assess a structural level explanation of racial disparity in child maltreatment. Using data from Florida counties (1998-2001) and the 2000 census, the effects of poverty, concentrated poverty, and female-headed families in poverty on Black, White, and the difference between Black-White rates of child…

  15. Black-white differences in infectious disease mortality in the United States

    NARCIS (Netherlands)

    J.H. Richardus (Jan Hendrik); A.E. Kunst (Anton)

    2001-01-01

    textabstractOBJECTIVES: This study determined the degree to which Black-White differences in infectious disease mortality are explained by income and education and the extent to which infectious diseases contribute to Black-White differences in all-cause mortality. METHODS: A sampl

  16. Cause-specific contributions to black-white differences in male mortality from 1960 to 1995

    Directory of Open Access Journals (Sweden)

    2004-04-01

    Full Text Available Between 1960 and 1995 the black-white difference in male life expectancy in the United States increased from 6.7 years to 8.2 years. To provide insights into why mortality trends have been more adverse for black men than for white men, we investigate which causes of death were principally responsible for changes in the black-white difference in male mortality at ages 15-64 between 1960 and 1995. We find that black-white differences in male mortality varied substantially during this period. The gap increased in the 1960s, declined in the 1970s, and widened in the 1980s-early 1990s. Our findings reveal considerable variation in black-white disparities by cause of death and by age, as well as changes in the relative importance of various causes of death to the black-white male mortality disparity over time. The results suggest that consequences of black-white differences in socioeconomic status, access to quality health care, living conditions, and residential segregation vary by cause of death.

  17. Soft skills, hard skills, and the black/white earnings gap

    OpenAIRE

    Fan, C. Simon; Wei, Xiangdong; Zhang, Junsen

    2005-01-01

    This paper provides both a theoretical and an empirical investigation into the impact of job skill types on the black/white pay differentials. The theoretical analysis derives that the more intensively soft/hard skills are used in an occupation, the greater/smaller the black/white pay differential is there in that occupation. Moreover, in response to the differential pay gaps across jobs requiring different levels of soft/hard skills, blacks are more likely to self-select themselves into the ...

  18. Permanent Income and the Black-White Test Score Gap. NBER Working Paper No. 17610

    Science.gov (United States)

    Rothstein, Jesse; Wozny, Nathan

    2011-01-01

    Analysts often examine the black-white test score gap conditional on family income. Typically only a current income measure is available. We argue that the gap conditional on permanent income is of greater interest, and we describe a method for identifying this gap using an auxiliary data set to estimate the relationship between current and…

  19. Self-Esteem and Other Motivational Variables: Some Black-White Comparisons

    Science.gov (United States)

    Trachtman, Joan; Denmark, Florence

    1973-01-01

    Argues that the stereotypical negative personality profiles of disadvantaged youth and the concept of black self-esteem may be changing in a more positive direction, based on a comparative research study of black-white differences along the dimensions of acceptance of authority, dogmatism, anomy, internality-externality, and self-esteem. (EH)

  20. Coincidence or Conspiracy? Whiteness, Policy and the Persistence of the Black/White Achievement Gap

    Science.gov (United States)

    Gillborn, David

    2008-01-01

    Adopting an approach shaped by critical race theory (CRT) the paper proposes a radical analysis of the nature of race inequality in the English educational system. Focusing on the relative achievements of White school leavers and their Black (African Caribbean) peers, it is argued that long standing Black/White inequalities have been obscured by a…

  1. Pelvic pain after childbirth: a longitudinal population study.

    Science.gov (United States)

    Bjelland, Elisabeth Krefting; Owe, Katrine Mari; Pingel, Ronnie; Kristiansson, Per; Vangen, Siri; Eberhard-Gran, Malin

    2016-03-01

    In this longitudinal population study, the aims were to study associations of mode of delivery with new onset of pelvic pain and changes in pelvic pain scores up to 7 to 18 months after childbirth. We included 20,248 participants enrolled in the Norwegian Mother and Child Cohort Study (1999-2008) without preexisting pelvic pain in pregnancy. Data were obtained by 4 self-administered questionnaires and linked to the Medical Birth Registry of Norway. A total of 4.5% of the women reported new onset of pelvic pain 0 to 3 months postpartum. Compared to unassisted vaginal delivery, operative vaginal delivery was associated with increased odds of pelvic pain (adjusted odds ratio [OR]: 1.30; 95% confidence interval [CI]: 1.06-1.59). Planned and emergency cesarean deliveries were associated with reduced odds of pelvic pain (adjusted OR: 0.48; 95% CI: 0.31-0.74 and adjusted OR: 0.65; 95% CI: 0.49-0.87, respectively). Planned cesarean delivery, young maternal age, and low Symptom Checklist-8 scores were associated with low pelvic pain scores after childbirth. A history of pain was the only factor associated with increased pelvic pain scores over time (P = 0.047). We conclude that new onset of pelvic pain after childbirth was not commonly reported, particularly following cesarean delivery. Overall, pelvic pain scores were rather low at all time points and women with a history of pain reported increased pelvic pain scores over time. Hence, clinicians should follow up women with pelvic pain after a difficult childbirth experience, particularly if they have a history of pain. PMID:26588694

  2. Pelvic pain after childbirth: a longitudinal population study.

    Science.gov (United States)

    Bjelland, Elisabeth Krefting; Owe, Katrine Mari; Pingel, Ronnie; Kristiansson, Per; Vangen, Siri; Eberhard-Gran, Malin

    2016-03-01

    In this longitudinal population study, the aims were to study associations of mode of delivery with new onset of pelvic pain and changes in pelvic pain scores up to 7 to 18 months after childbirth. We included 20,248 participants enrolled in the Norwegian Mother and Child Cohort Study (1999-2008) without preexisting pelvic pain in pregnancy. Data were obtained by 4 self-administered questionnaires and linked to the Medical Birth Registry of Norway. A total of 4.5% of the women reported new onset of pelvic pain 0 to 3 months postpartum. Compared to unassisted vaginal delivery, operative vaginal delivery was associated with increased odds of pelvic pain (adjusted odds ratio [OR]: 1.30; 95% confidence interval [CI]: 1.06-1.59). Planned and emergency cesarean deliveries were associated with reduced odds of pelvic pain (adjusted OR: 0.48; 95% CI: 0.31-0.74 and adjusted OR: 0.65; 95% CI: 0.49-0.87, respectively). Planned cesarean delivery, young maternal age, and low Symptom Checklist-8 scores were associated with low pelvic pain scores after childbirth. A history of pain was the only factor associated with increased pelvic pain scores over time (P = 0.047). We conclude that new onset of pelvic pain after childbirth was not commonly reported, particularly following cesarean delivery. Overall, pelvic pain scores were rather low at all time points and women with a history of pain reported increased pelvic pain scores over time. Hence, clinicians should follow up women with pelvic pain after a difficult childbirth experience, particularly if they have a history of pain.

  3. Another look at the relationship between socioeconomic factors and the black-white health benefit inequality.

    Science.gov (United States)

    Ohn, Jonathan; McMahon, Lauren; Carter, Tony

    2006-01-01

    This paper illustrates the black-white disparity in health benefit coverage and the socioeconomic variables-unemployment, income, and education. The health benefit disparity is strongly related to the disparity in underlying socioeconomic variables. Moreover, the time-series examination reveals that the change in white workers' health insurance coverage is largely determined by its year-to-year persistence and the labor market tightness (or the business cycle), while that of black workers is largely determined by the change in their earnings with a slight persistence. The effect of the change in annual earnings seems to dominate the effect of the labor market condition (unemployment rate) and other variables. Finally, although marginally significant, an increase in the attainment of higher education (college) has a positive effect on the black-white health benefit disparity.

  4. Thoracic posterior longitudinal ligament ossification in a fixed population; longitudinal radiological observations

    International Nuclear Information System (INIS)

    All lateral chest radiographs of 34 persons with posterior longitudinal ligament ossification (PLLO) in the thoracic spine were reviewed for date of its onset and its progress. These observations spanned as long as 18 years. Upper mid-thoracic PLLO first appeared under the age of 40, then increased in extent in the vertical axis until the age of 50. Lower thoracic PLLO occurred later than upper mid-thoracic PLLO. In the lower thoracic and lumbar regions, degeneration of the vertebrae and discs apparently were focal factors which triggered the development of thoracic PLLO. PLLO apparently developed in a different way in the upper and mid-thoracic regions, where the vertebrae and discs were unremarkable at the time of its initial appearance, and degenerative abnormalities did not predispose to it. (author)

  5. Sleep Problems in Children with Autism Spectrum Problems: A Longitudinal Population-Based Study

    Science.gov (United States)

    Sivertsen, Borge; Posserud, Maj-Britt; Gillberg, Christopher; Lundervold, Astri J.; Hysing, Mari

    2012-01-01

    This study examined the prevalence and chronicity of sleep problems in children who manifest problems believed to be typical of Autism Spectrum Disorders (ASD). Using data from a longitudinal total population study, symptoms of ASD, insomnia and potential explanatory factors were assessed at ages 7-9 and 11-13. Children were included in a group…

  6. Birth weight and cognitive function in the British 1946 birth cohort: longitudinal population based study

    OpenAIRE

    M. Richards; HARDY, R.; Kuh, D.; Wadsworth, M E J

    2001-01-01

    Objective To examine the association between birth weight and cognitive function in the normal population.Design A longitudinal, population based, birth cohort study.Participants 3900 males and females born in 1946.Main outcome measures Cognitive function from childhood to middle life (measured at ages 8, 11, 15, 26, and 43 years).Results Birth weight was significantly and positively associated with cognitive ability at age 8 (with an estimated standard deviation score of 0.44 (95%, confidenc...

  7. Black-white differences in the economic value of improving health.

    Science.gov (United States)

    Murphy, Kevin M; Topel, Robert H

    2005-01-01

    This article examines how differences in longevity over time and across groups add to the typical measures of economic progress and intergroup differentials. We focus on gains for and differences between groups defined both by race (black and white) and by gender, relying on willingness to pay as our measure of the economic value of gains in longevity. Measured at birth, the gains for white males between 1968 and 1998 were about 245,000 dollars per person, while the gains for black males were far larger, about 390,000 dollars per person. The gains for women were somewhat smaller, with white females gaining about 150,000 dollars per person and black females gaining about 305,000 dollars per person. Our estimates suggest that differences in income explain about 1/3 to 1/2 of the current black-white gap in longevity. PMID:15842095

  8. Is the Black-White Achievement Gap a Public Sector Effect? An Examination of Student Achievement in the Third Grade

    Science.gov (United States)

    Simms, Kathryn

    2012-01-01

    Prior research has suggested private school education in middle school and high school as a solution for the Black-White achievement gap. However, more recent research calls this solution into question. Additionally, research increasingly implicates third grade as being of preeminent importance in driving students' subsequent academic achievement.…

  9. It Does Not Have to Be Uncomfortable: The Role of Behavioral Scripts in Black-White Interracial Interactions

    Science.gov (United States)

    Avery, Derek R.; Richeson, Jennifer A.; Hebl, Michelle R.; Ambady, Nalini

    2009-01-01

    Despite growing racioethnic diversity in U.S. organizations, few organizational studies have focused on Black-White interracial interactions. Two experiments examined the influence of interaction roles, and the social scripts they trigger, on White participants' anxiety during dyadic interactions with Black partners. Results from both studies…

  10. Black-White Residential Segregation: The Views of Myrdal in the 1940s and Trends of the 1980s.

    Science.gov (United States)

    Farley, Reynolds

    1994-01-01

    Traces the development of black-white residential segregation in U.S. cities, and applies the views of Gunnar Myrdal, expressed in the 1940s, to housing trends in the 1980s. While such segregation has decreased, blacks remain more segregated than two other large minority groups (i.e., Hispanics and Asians). Forces influencing residential…

  11. Can insomnia in pregnancy predict postpartum depression? A longitudinal, population-based study

    OpenAIRE

    Dørheim, Signe K.; Bjørn Bjorvatn; Malin Eberhard-Gran

    2014-01-01

    Background: Insomnia and depression are strongly interrelated. This study aimed to describe changes in sleep across childbirth, and to evaluate whether insomnia in pregnancy is a predictor of postpartum depression. Methods: A longitudinal, population-based study was conducted among perinatal women giving birth at Akershus University Hospital, Norway. Women received questionnaires in weeks 17 and 32 of pregnancy and eight weeks postpartum. This paper presents data from 2,088 of 4,662 women ...

  12. Population income and longitudinal trends in living kidney donation in the United States.

    Science.gov (United States)

    Gill, Jagbir; Dong, Jianghu; Gill, John

    2015-01-01

    Living kidney donation is declining in the United States. We examined longitudinal trends in living donation as a function of median household income and donor relation to assess the effect of financial barriers on donation in a changing economic environment. The zip code-level median household income of all 71,882 living donors was determined by linkage to the 2000 US Census. Longitudinal changes in the rate of donation were determined in income quintiles between 1999 and 2004, when donations were increasing, and between 2005 and 2010, when donations were declining. Rates were adjusted for population differences in age, sex, race, and ESRD rate using multilevel linear regression models. Between 1999 and 2004, the rate of growth in living donation per million population was directly related to income, increasing progressively from the lowest to highest income quintile, with annualized changes of 0.55 (95% confidence interval [95% CI], 0.14 to 1.05) for Q1 and 1.77 (95% CI, 0.66 to 2.77) for Q5 (Pincome with longitudinal changes also varied by donor relationship. In conclusion, changes in living donation in the past decade varied by median household income, resulting in increased disparities in donation between low- and high-income populations. These findings may inform public policies to support living donation during periods of economic volatility.

  13. Quality of life among prostate cancer patients: A prospective longitudinal population-based study

    International Nuclear Information System (INIS)

    Purpose: To investigate the course of quality of life (QoL) among prostate cancer patients treated with external beam radiotherapy and to compare the results with QoL of a normal age-matched reference population. Patients and methods: The study population was composed of 227 prostate cancer patients, treated with radiotherapy. The EORTC QLQ-C30 was used to assess QoL before radiotherapy and six months, one year, two years and three years after completion of radiotherapy. Mixed model analyses were used to investigate longitudinal changes in QoL. QoL of prostate cancer patients was compared to that of a normative cohort using a multivariate analysis of covariance. Results: A significant decline in QoL was observed after radiotherapy (p < 0.001). The addition of hormonal therapy to radiotherapy was associated with a lower level of role functioning. Patients with coronary heart disease and or chronic obstructive pulmonary disease or asthma had a significantly worse course in QoL. Although statistically significant, all differences were classified as small or trivial. Conclusion: Prostate cancer patients experience a small worsening of QoL as compared with baseline and as compared with a normal reference population. As co-morbidity modulates patients’ post-treatment QoL, a proper assessment of co-morbidity should be included in future longitudinal analyses on QoL

  14. Lead, mercury and arsenic content in spices: Black, white and green pepper, black cumin and ginger

    Directory of Open Access Journals (Sweden)

    Blagojević Slavica M.

    2015-01-01

    Full Text Available In order to evaluate the safety of selected commercial spices brands, concentration of lead, mercury and arsenic, as well as moisture and mineral contents were analyzed in samples of dried black and white pepper powders, black, white and green peppercorns, black cumin seeds and ginger powder. Lead (Pb, mercury (Hg and arsenic (As concentrations in spice samples purchased from local markets in Belgrade were determined, after a microwave digestion of the samples, by atomic absorption spectrometry (AAS, using the graphite furnace AAS technique (Pb, cold vapor AAS technique (Hg and hydride generation AAS technique (As. Trace levels of Pb, Hg and As in the selected dried spices samples were in the range 0.10 ppm - 0.79 ppm, 0.01 ppm - 0.10 ppm and 0.01 ppm - 0.51 ppm, respectively. The maximum Pb concentration was determined in the sample of ginger and it was 0.79 ppm, the maximum concentration of Hg was 0.10 ppm, determined in green peppercorns samples, while the maximum concentration of As in powdered black pepper sample was 0.51 ppm. The moisture and mineral contents in the different analyzed spices were in the range 1.70-13.10% and 3.40-6.50%, respectively. According to the obtained results, the concentrations of the analyzed toxic elements, as well as the moisture and mineral content in selected spices, were below the maximum permissible limits declared by the national legislations deemed safe for human consumption. [Projekat Ministarstva nauke Republike Srbije, br. 172015

  15. Black-White Latino Racial Disparities in HIV Survival, Florida, 2000-2011.

    Science.gov (United States)

    Sheehan, Diana M; Trepka, Mary Jo; Fennie, Kristopher P; Prado, Guillermo; Cano, Miguel Ángel; Maddox, Lorene M

    2016-01-01

    This research aimed to estimate Black/White racial disparities in all-cause mortality risk among HIV-positive Latinos. Florida surveillance data for Latinos diagnosed with HIV (2000-2008) were merged with 2007-2011 American Community Survey data. Crude and adjusted hazard ratios (aHR) were calculated using multi-level Cox regression. Of 10,903 HIV-positive Latinos, 8.2% were Black and 91.9% White. Black Latinos were at increased mortality risk compared with White Latinos after controlling for individual and neighborhood factors (aHR 1.40, 95% confidence interval (CI) 1.21-1.62). In stratified analyses, risk factors for Black Latinos included: age ≥60 years compared with ages 13-19 (aHR 4.63, 95% CI 1.32-16.13); US birth compared with foreign birth (aHR 1.56, 95% CI 1.16-2.11); diagnosis of AIDS within three months of HIV diagnosis (aHR 3.53, 95% CI 2.64-4.74); residence in the 3rd (aHR 1.82, 95% CI 1.13-2.94) and 4th highest quartiles (aHR 1.79, 95% CI 1.12-2.86) of neighborhood poverty compared with the lowest quartile; and residence in neighborhood with 25%-49% (aHR 1.59, 95% CI 1.07-2.42) and ≥50% Latinos compared with <25% Latinos (aHR 1.58, 95% CI 1.03-2.42). Significant racial disparities in HIV survival exist among Latinos. Differential access to-and quality of-care and perceived/experienced racial discrimination may be possible explanations. PMID:26703656

  16. Education and Alcohol Consumption among Older Americans; Black-White Differences

    Directory of Open Access Journals (Sweden)

    Shervin eAssari

    2016-04-01

    Full Text Available Abstract:Purpose: Although the link between education and alcohol consumption is known, limited information exists on racial differences in this link. We conducted the current study to test Black- White differences in the association between education and alcohol consumption among older adults in the United States. Methods: This cross-sectional survey enrolled 1,493 Black (n=734 and White (n=759 older adults (age 66 or more in United States. Data came from the Religion, Aging, and Health Survey, 2001. Race, demographics, socio-economics, and alcohol consumption were measured. Independent variable was education level. Outcome was alcohol consumption. Race was the focal moderator. Logistic regression was used for data analysis. Results: Education was positively associated with ever drinking in the pooled sample. Race, however, interacted with education level on drinking, suggesting a smaller effect of education on drinking for Blacks compared to Whites. Among Whites, high school graduation and college graduation were associated with increased odds of ever drinking, net of covariates. Among Blacks, high school graduation but not college graduation was associated with ever drinking. Conclusion: Blacks and Whites differ in how socio-economic status (i.e. education shapes behaviors health behaviors (i.e. drinking. How race modifies consequences and correlates of social determinants of health is not yet clear. College graduation may result in the same level of change to the social network and income of race group members. Lower effect of education on health of Blacks may be due to the structural role of race and racism that has resulted in lower job availability and pay for Blacks.

  17. Changes in Dental Students' Attitudes About Treating Underserved Populations: A Longitudinal Study.

    Science.gov (United States)

    Major, Nicole; McQuistan, Michelle R; Qian, Fang

    2016-05-01

    The aim of this study was to assess changes in a group of dental students' feelings about, willingness to treat, and perceived responsibility in treating underserved populations as they progressed through their predoctoral education. A questionnaire was developed to assess the first- through fourth-year (D1-D4) students' attitudes about treating 13 underserved populations after graduation. Surveys were distributed from 2008 to 2014, resulting in longitudinal data from three graduating classes (D1 year: N=240; eligible D4 participants: N=221). A total of 132 students from the three classes (Class of 2012 N=41; 2013 N=46; 2014 N=45; adjusted response rate 60%) completed all surveys (D1-D4). The results showed that changes in students' feelings about treating and willingness to treat underserved populations were population-specific rather than universal. Compared to the D1 year, the students in later years anticipated feeling more negatively towards treating low-income, frail elderly, homebound, homeless, other ethnic groups, and non-English-speaking patients, while their feelings were more positive towards treating known drug users and HIV/AIDS populations. Across the four years, students' willingness to treat low-income, frail elderly, homebound, and non-English-speaking populations after graduation became more negative, while their willingness to treat medically complex populations, known drug users, and HIV/AIDS populations became more positive. The students also became less likely to strongly agree that it is their responsibility as dentists to treat underserved populations as they progressed through school. These respondents reported that clinical and faculty interactions had impacted their likelihood to treat underserved populations. These findings may point to specific types of interventions and faculty mentoring to bring about change. PMID:27139202

  18. Population size structure of non-native fishes along longitudinal gradients in a highly regulated Mediterranean basin.

    OpenAIRE

    Fátima Amat-Trigo

    2015-01-01

    Population size structure can provide insights in species-specific knowledge and fish management. The purpose of the present study is to assess the influence of hydrological flow variability along the longitudinal gradient in the population size structure metrics of three non-native fish species widely distributed in the Iberian Peninsula, Alburnus alburnus L., Lepomis gibbosus L. and Gobio lozanoi Doadrio & Madeira, 2004. We analysed populations at site level (29 sampling localities in fluvi...

  19. Longitudinal variability of time-location/activity patterns of population at different ages: a longitudinal study in California

    Directory of Open Access Journals (Sweden)

    Cassady Diana L

    2011-09-01

    Full Text Available Abstract Background Longitudinal time-activity data are important for exposure modeling, since the extent to which short-term time-activity data represent long-term activity patterns is not well understood. This study was designed to evaluate longitudinal variations in human time-activity patterns. Method We report on 24-hour recall diaries and questionnaires collected via the internet from 151 parents of young children (mostly under age 55, and from 55 older adults of ages 55 and older, for both a weekday and a weekend day every three months over an 18-month period. Parents also provided data for their children. The self-administrated diary and questionnaire distinguished ~30 frequently visited microenvironments and ~20 activities which we selected to represent opportunities for exposure to toxic environmental compounds. Due to the non-normal distribution of time-location/activity data, we employed generalized linear mixed-distribution mixed-effect models to examine intra- and inter-individual variations. Here we describe variation in the likelihood of and time spent engaging in an activity or being in a microenvironment by age group, day-type (weekday/weekend, season (warm/cool, sex, employment status, and over the follow-up period. Results As expected, day-type and season influence time spent in many location and activity categories. Longitudinal changes were also observed, e.g., young children slept less with increasing follow-up, transit time increased, and time spent on working and shopping decreased during the study, possibly related to human physiological changes with age and changes in macro-economic factors such as gas prices and the economic recession. Conclusions This study provides valuable new information about time-activity assessed longitudinally in three major age groups and greatly expands our knowledge about intra- and inter-individual variations in time-location/activity patterns. Longitudinal variations beyond weekly and

  20. Longitudinal Changes in Vascular Risk Markers and Mortality Rates among a Latino Population with Hypertension.

    Science.gov (United States)

    Pflederer, Matthew C; Long, Carlin S; Beaty, Brenda; Havranek, Edward P; Mehler, Philip S; Keniston, Angela; Krantz, Mori J

    2016-04-01

    Vascular markers such as pulse-wave velocity and carotid intima-media thickness (CIMT) might improve the prediction of incident cardiovascular disease beyond traditional risk factors. These vascular markers have not been well characterized in minority populations and might be more useful than inflammatory biomarkers. We conducted a prospective, longitudinal cohort study among hypertensive patients in an urban safety-net hospital. We evaluated inflammatory biomarkers, arterial pulse-wave velocity, and carotid intima-media thickness at baseline, 1 year, and 2 years. The primary outcome variable was CIMT. Generalized linear mixed-effects models were used to evaluate associations between CIMT and predictive variables accounting for the correlation of multiple measurements within subjects over time. For our secondary outcome, we used administrative and National Death Index data to determine all-cause death, and univariate relationships were evaluated. Among 175 subjects, 117 were Latino (67%) and 117 were female (67%). Pulse-wave velocity and CIMT regressed over time (both P <0.001) and were highly correlated (P <0.001). Only pulse-wave velocity (P=0.002) and total cholesterol (P=0.03) were associated with CIMT in time-varying covariate analysis. At a median follow-up period of 80 months, 17 of 175 subjects had died (10%). Higher baseline CIMT and pulse-wave velocity were associated with increased mortality rates (both P <0.01). No serum inflammatory marker was significantly correlated with longitudinal changes in CIMT or death. In conclusion, both arterial stiffness and preclinical carotid atherosclerosis were associated with increased mortality rates and might be useful risk-stratification markers among this minority population.

  1. Inconsistent self-reported mammography history: Findings from the National Population Health Survey longitudinal cohort

    Directory of Open Access Journals (Sweden)

    Snider Judy

    2004-11-01

    Full Text Available Abstract Background Self-reported information has commonly been used to monitor mammography utilization across populations and time periods. However, longitudinal investigations regarding the prevalence and determinants of inconsistent responses over time and the impact of such responses on population screening estimates are lacking. Methods Based on longitudinal panel data for a representative cohort of Canadian women aged 40+ years (n = 3,537 assessed in the 1994–95 (baseline and 1996–97 (follow-up National Population Health Survey (NPHS, we examined the prevalence of inconsistent self-reports of mammography utilization. Logistic regression models were used to estimate the associations between women's baseline sociodemographic and health characteristics and 2 types of inconsistent responses: (i baseline reports of ever use which were subsequently contradicted by follow-up reports of never use; and (ii baseline reports of never use which were contradicted by follow-up reports of use prior to 1994–95. Results Among women who reported having a mammogram at baseline, 5.9% (95% confidence interval (CI: 4.6–7.3% reported at follow-up that they had never had one. Multivariate logistic regression analyses showed that women with such inconsistent responses were more often outside target age groups, from low income households and less likely to report hormone replacement therapy and Pap smear use. Among women reporting never use at baseline and ever use at follow-up, 17.4% (95%CI: 11.7–23.1% reported their most recent mammogram as occurring prior to 1994–95 (baseline and such responses were more common among women aged 70+ years and those in poorer health. Conclusions Women with inconsistent responses of type (i, i.e., ever users at baseline but never users at follow-up, appeared to exhibit characteristics typical of never users of mammography screening. Although limited by sample size, our preliminary analyses suggest that type (ii

  2. Eating Problems and Their Risk Factors: A 7-Year Longitudinal Study of a Population Sample of Norwegian Adolescent Girls

    Science.gov (United States)

    Kansi, Juliska; Wichstrom, Lars; Bergman, Lars R.

    2005-01-01

    The longitudinal stability of eating problems and their relationships to risk factors were investigated in a representative population sample of 623 Norwegian girls aged 13-14 followed over 7 years (3 time points). Three eating problem symptoms were measured: Restriction, Bulimia-food preoccupation, and Diet, all taken from the 12-item Eating…

  3. Cardiovascular events in patients with atherothrombotic disease: a population-based longitudinal study in Taiwan.

    Directory of Open Access Journals (Sweden)

    Wen-Hsien Lee

    Full Text Available BACKGROUND: Atherothrombotic diseases including cerebrovascular disease (CVD, coronary artery disease (CAD, and peripheral arterial disease (PAD, contribute to the major causes of death in the world. Although several studies showed the association between polyvascular disease and poor cardiovascular (CV outcomes in Asian population, there was no large-scale study to validate this relationship in this population. METHODS AND RESULTS: This retrospective cohort study included patients with a diagnosis of CVD, CAD, or PAD from the database contained in the Taiwan National Health Insurance Bureau during 2001-2004. A total of 19954 patients were enrolled in this study. The atherothrombotic disease score was defined according to the number of atherothrombotic disease. The study endpoints included acute coronary syndrome (ACS, all strokes, vascular procedures, in hospital mortality, and so on. The event rate of ischemic stroke (18.2% was higher than that of acute myocardial infarction (5.7% in our patients (P = 0.0006. In the multivariate Cox regression analyses, the adjusted hazard ratios (HRs of each increment of atherothrombotic disease score in predicting ACS, all strokes, vascular procedures, and in hospital mortality were 1.41, 1.66, 1.30, and 1.14, respectively (P≦0.0169. CONCLUSIONS: This large population-based longitudinal study in patients with atherothrombotic disease demonstrated the risk of subsequent ischemic stroke was higher than that of subsequent AMI. In addition, the subsequent adverse CV events including ACS, all stroke, vascular procedures, and in hospital mortality were progressively increased as the increase of atherothrombotic disease score.

  4. Longitudinal, population-based study of racial/ethnic differences in colorectal cancer survival: impact of neighborhood socioeconomic status, treatment and comorbidity

    International Nuclear Information System (INIS)

    Colorectal cancer, if detected early, has greater than 90% 5-year survival. However, survival has been shown to vary across racial/ethnic groups in the United States, despite the availability of early detection methods. This study evaluated the joint effects of sociodemographic factors, tumor characteristics, census-based socioeconomic status (SES), treatment, and comorbidities on survival after colorectal cancer among and within racial/ethnic groups, using the SEER-Medicare database for patients diagnosed in 1992–1996, and followed through 1999. Unadjusted colorectal cancer-specific mortality rates were higher among Blacks and Hispanic males than whites (relative rates (95% confidence intervals) = 1.34 (1.26–1.42) and 1.16 (1.04–1.29), respectively), and lower among Japanese (0.78 (0.70–0.88)). These patterns were evident for all-cause mortality, although the magnitude of the disparity was larger for colorectal cancer mortality. Adjustment for stage accounted for the higher rate among Hispanic males and most of the lower rate among Japanese. Among Blacks, stage and SES accounted for about half of the higher rate relative to Whites, and within stage III colon and stages II/III rectal cancer, SES completely accounted for the small differentials in survival between Blacks and Whites. Comorbidity did not appear to explain the Black-White differentials in colorectal-specific nor all-cause mortality, beyond stage, and treatment (surgery, radiation, chemotherapy) explained a very small proportion of the Black-White difference. The fully-adjusted relative mortality rates comparing Blacks to Whites was 1.14 (1.09–1.20) for all-cause mortality and 1.21 (1.14–1.29) for colorectal cancer specific mortality. The sociodemographic, tumor, and treatment characteristics also had different impacts on mortality within racial/ethnic groups. In this comprehensive analysis, race/ethnic-specific models revealed differential effects of covariates on survival after colorectal

  5. Burden of diabetes mellitus estimated with a longitudinal population-based study using administrative databases.

    Directory of Open Access Journals (Sweden)

    Luciana Scalone

    Full Text Available OBJECTIVE: To assess the epidemiologic and economic burden of diabetes mellitus (DM from a longitudinal population-based study. RESEARCH DESIGN AND METHODS: Lombardy Region includes 9.9 million individuals. Its DM population was identified through a data warehouse (DENALI, which matches with a probabilistic linkage demographic, clinical and economic data of different Healthcare Administrative databases. All individuals, who, during the year 2000 had an hospital discharge with a IDC-9 CM code 250.XX, and/or two consecutive prescriptions of drugs for diabetes (ATC code A10XXXX within one year, and/or an exemption from co-payment healthcare costs specific for DM, were selected and followed up to 9 years. We calculated prevalence, mortality and healthcare costs (hospitalizations, drugs and outpatient examinations/visits from the National Health Service's perspective. RESULTS: We identified 312,223 eligible subjects. The study population (51% male had a mean age of 66 (from 0.03 to 105.12 years at the index date. Prevalence ranged from 0.4% among subjects aged ≤45 years to 10.1% among those >85 years old. Overall 43.4 deaths per 1,000 patients per year were estimated, significantly (p<0.001 higher in men than women. Overall, 3,315€/patient-year were spent on average: hospitalizations were the cost driver (54.2% of total cost. Drugs contributed to 31.5%, outpatient claims represented 14.3% of total costs. Thirty-five percent of hospital costs were attributable to cerebro-/cardiovascular reasons, 6% to other complications of DM, and 4% to DM as a main diagnosis. Cardiovascular drugs contributed to 33.5% of total drug costs, 21.8% was attributable to class A (16.7% to class A10 and 4.3% to class B (2.4% to class B01 drugs. CONCLUSIONS: Merging different administrative databases can provide with many data from large populations observed for long time periods. DENALI shows to be an efficient instrument to obtain accurate estimates of burden of

  6. Postindustrial Capitalism and the Problems with Bourdieu's Social and Cultural Capital in Understanding the Black/White Achievement Gap in the United States and United Kingdom

    Science.gov (United States)

    Mocombe, Paul C.

    2015-01-01

    This hermeneutical essay demonstrates why and how Pierre Bourdieu's social reproduction theory is neither an adequate explanation for understanding praxis nor the Black/White academic achievement gap in contemporary postindustrial economies like that of the United States and the United Kingdom. The underlining hypothesis of the work is that the…

  7. Can insomnia in pregnancy predict postpartum depression? A longitudinal, population-based study.

    Directory of Open Access Journals (Sweden)

    Signe K Dørheim

    Full Text Available BACKGROUND: Insomnia and depression are strongly interrelated. This study aimed to describe changes in sleep across childbirth, and to evaluate whether insomnia in pregnancy is a predictor of postpartum depression. METHODS: A longitudinal, population-based study was conducted among perinatal women giving birth at Akershus University Hospital, Norway. Women received questionnaires in weeks 17 and 32 of pregnancy and eight weeks postpartum. This paper presents data from 2,088 of 4,662 women with complete data for insomnia and depression in week 32 of pregnancy and eight weeks postpartum. Sleep times, wake-up times and average sleep durations were self-reported. The Bergen Insomnia Scale (BIS was used to measure insomnia. The Edinburgh Postnatal Depression Scale (EPDS was used to measure depressive symptoms. RESULTS: After delivery, sleep duration was reduced by 49 minutes (to 6.5 hours, and mean sleep efficiency was reduced from 84% to 75%. However, self-reported insomnia scores (BIS improved from 17.2 to 15.4, and the reported prevalence of insomnia decreased from 61.6% to 53.8%. High EPDS scores and anxiety in pregnancy, fear of delivery, previous depression, primiparity, and higher educational level were risk factors for both postpartum insomnia and depression. Insomnia did not predict postpartum depression in women with no prior history of depression, whereas women who recovered from depression had residual insomnia. LIMITATIONS: Depression and insomnia were not verified by clinical interviews. Women with depressive symptoms were less likely to remain in the study. CONCLUSIONS: Although women slept fewer hours at night after delivery compared to during late pregnancy, and reported more nights with nighttime awakenings, their self-reported insomnia scores improved, and the prevalence of insomnia according to the DSM-IV criteria decreased. Insomnia in pregnancy may be a marker for postpartum recurrence of depression among women with previous

  8. Mental illness related disparities in diabetes prevalence, quality of care and outcomes: a population-based longitudinal study

    OpenAIRE

    Emery Jonathan D; Sanfilippo Frank M; Holman C D'Arcy J; Mai Qun; Preen David B

    2011-01-01

    Abstract Background Health care disparity is a public health challenge. We compared the prevalence of diabetes, quality of care and outcomes between mental health clients (MHCs) and non-MHCs. Methods This was a population-based longitudinal study of 139,208 MHCs and 294,180 matched non-MHCs in Western Australia (WA) from 1990 to 2006, using linked data of mental health registry, electoral roll registrations, hospital admissions, emergency department attendances, deaths, and Medicare and pharm...

  9. Labor market segmentation and relative black/white teenage birth rates.

    Science.gov (United States)

    Mccrate, E

    1990-01-01

    "Teenage mothers typically have lower educational attainment than other women. Most observers have argued that this is a major reason for their greater risk of poverty. This article takes the opposite view: that circumstances associated with poverty contribute to a greater likelihood of teenage childbearing. In particular, poor educational quality and the chances of secondary sector employment are more common for black women, regardless of their age at first birth. Hence the payoffs to education may be quite low for these women, which may be the reason for early motherhood. This argument is presented in terms of segmented labor market theory. Data to support it is presented from the [U.S.] National Longitudinal Survey of Youth. Other common explanations of teenage motherhood are critiqued." PMID:12285449

  10. Labor market segmentation and relative black/white teenage birth rates.

    Science.gov (United States)

    Mccrate, E

    1990-01-01

    "Teenage mothers typically have lower educational attainment than other women. Most observers have argued that this is a major reason for their greater risk of poverty. This article takes the opposite view: that circumstances associated with poverty contribute to a greater likelihood of teenage childbearing. In particular, poor educational quality and the chances of secondary sector employment are more common for black women, regardless of their age at first birth. Hence the payoffs to education may be quite low for these women, which may be the reason for early motherhood. This argument is presented in terms of segmented labor market theory. Data to support it is presented from the [U.S.] National Longitudinal Survey of Youth. Other common explanations of teenage motherhood are critiqued."

  11. Black/White Differences in Perceived Weight and Attractiveness among Overweight Women

    Directory of Open Access Journals (Sweden)

    Taona P. Chithambo

    2013-01-01

    Full Text Available Numerous studies have reported that Black women are more satisfied with their bodies than White women. The buffering hypothesis suggests that aspects of Black culture protect Black women against media ideals that promote a slender female body type; therefore, Black women are expected to exhibit higher body esteem than White women. To test this hypothesis, the current study aimed to assess the influence of race on weight perception, perceived attractiveness, and the interrelations between body mass index (BMI and perceived attractiveness among overweight and obese women. Participants were 1,694 respondents of Wave IV of the National Longitudinal Study on Adolescent Health ( years. Black ( or White ( obese or overweight women were included in the current study. As expected, Black women reported lower perceived weight and higher attractiveness than White women, despite higher body mass for Black women. Furthermore, race moderated the relationship between BMI and perceived attractiveness; for White women, a negative relationship existed between BMI and attractiveness, whereas for Black women, BMI and attractiveness were not related. The study findings provide further support for the buffering hypothesis, indicating that despite higher body mass, overweight Black women are less susceptible to thin body ideals than White women.

  12. Longitudinal clinical and radiographic evaluation of severely intruded permanent incisors in a pediatric population.

    Science.gov (United States)

    Neto, José Jeová Siebra Moreira; Gondim, Juliana Oliveira; de Carvalho, Fernanda Matias; Giro, Elisa Maria Aparecida

    2009-10-01

    Intrusion is defined as the axial dislodgment of the tooth into its socket and is considered one of the most severe types of dental trauma. This longitudinal outcome study was undertaken to evaluate clinically and radiographically severely intruded permanent incisors in a population of children and adolescents. All cases were treated between September 2003 and February 2008 in a dental trauma service. Clinical and radiographic data were collected from 12 patients (eight males and four females) that represented 15 permanent maxillary incisors. Mean age at the time of injury was 8 years and 9 months (range 7-14 years and 8 months). Mean time elapsed to follow-up was 26.6 months (range 10-51 months). The analysis of data showed that tooth intrusion was twice as frequent in males. The maxillary central incisors were the most commonly intruded teeth (93.3%), and falling at home was the main etiologic factor (60%). More than half of the cases (53.3%) were multiple intrusions, 73.3% of the intruded teeth had incomplete root formation and 66.6% of the teeth suffered other injuries concomitant to intrusion. Immediate surgical repositioning was the treatment of choice in 66.7% of the cases, while watchful waiting for the tooth to return to its pre-injury position was adopted in 33.3% of the cases. The teeth that suffered additional injuries to the intrusive luxation presented a fivefold increased relative risk of developing pulp necrosis. The immature teeth had six times more chances of presenting pulp canal obliteration that the mature teeth and a lower risk of developing root resorption. The most frequent post-injury complications were pulp necrosis (73.3%), marginal bone loss (60%), inflammatory root resorption (40%), pulp canal obliteration (26.7%) and replacement root resorption (20%). From the results of this study, it was not possible to determine whether the type immediate treatment had any influence on the appearance of sequelae like pulp necrosis and root

  13. The Influence of Place on Weight Gain during Early Childhood: A Population-Based, Longitudinal Study

    OpenAIRE

    Carter, Megan Ann; Dubois, Lise; Tremblay, Mark S; Taljaard, Monica

    2012-01-01

    The objective of this paper was to determine the influence of place factors on weight gain in a contemporary cohort of children while also adjusting for early life and individual/family social factors. Participants from the Québec Longitudinal Study of Child Development comprised the sample for analysis (n = 1,580). A mixed-effects regression analysis was conducted to determine the longitudinal relationship between these place factors and standardized BMI, from age 4 to 10 years. The average ...

  14. Evidence for a persistent, environment-dependent and deteriorating subtype of subclinical psychotic experiences : a 6-year longitudinal general population study

    NARCIS (Netherlands)

    Wigman, J.T.; van, Winkel R.; Raaijmakers, Q.A.; Ormel, J.; Verhulst, F.C.; Reijneveld, S.A.; van, Os J.; Vollebergh, W.A.

    2011-01-01

    Background. Research suggests that subclinical psychotic experiences during adolescence represent the behavioral expression of liability for psychosis. Little is known, however, about the longitudinal trajectory of liability in general population samples. Method. Growth mixture modeling was used to

  15. The Black-White paradox in health: flourishing in the face of social inequality and discrimination.

    Science.gov (United States)

    Keyes, Corey L M

    2009-12-01

    This paper reviews published research and presents new analyses from the 1995 nationally representative sample from the Midlife in the United States (MIDUS) study to investigate whether there is support for the paradox of race and health in the United States. Findings reveal that Blacks have lower rates of several common mental disorders, but Blacks also have higher rates of flourishing than Whites. Blacks are mentally resilient in the face of greater social inequality and exposure to discrimination as well as high rates of physical morbidity--all of which are distinctive risk factors for mental distress and mental illness in the general population. Findings also show that controlling for perceived discrimination increases the Black advantage in 12 of the 13 signs of flourishing, suggesting that Blacks would have even better mental health were it not for discrimination. This paper concludes by considering what mechanisms--both adaptive and maladaptive--might explain this particular example of resilience in the Black population. PMID:19796064

  16. Visual Impairment, Hearing Loss and Cognitive Function in an Older Population: Longitudinal Findings from the Blue Mountains Eye Study

    OpenAIRE

    Hong, Thomas; Mitchell, Paul; Burlutsky, George; Liew, Gerald; Wang, Jie Jin

    2016-01-01

    The presence of visual impairment (VI) and hearing loss (HL) with may be a marker for subsequent cognitive decline over time in older people. A prospective, longitudinal population-based study of the 3654 participants of the Blue Mountains Eye Study were assessed for the associations between VI and HL and a decline in mini-mental state examination (MMSE) scores over a duration of 10 years from the 5-year (baseline of this report) to the 15-year follow-up visits. MMSE was assessed at the 5-, 1...

  17. Predictors of Disordered Eating in Adolescence and Young Adulthood: A Population-Based, Longitudinal Study of Females and Males in Norway

    Science.gov (United States)

    Abebe, Dawit Shawel; Torgersen, Leila; Lien, Lars; Hafstad, Gertrud S.; von Soest, Tilmann

    2014-01-01

    We investigated longitudinal predictors for disordered eating from early adolescence to young adulthood (12-34 years) across gender and different developmental phases among Norwegian young people. Survey data from a population-based sample were collected at four time points (T) over a 13-year time span. A population-based sample of 5,679 females…

  18. Quality of life among prostate cancer patients : A prospective longitudinal population-based study

    NARCIS (Netherlands)

    Schaake, Wouter; de Groot, Martijn; Krijnen, Wim P.; Langendijk, Johannes A.; van den Bergh, Alfons C. M.

    2013-01-01

    Purpose: To investigate the course of quality of life (QoL) among prostate cancer patients treated with external beam radiotherapy and to compare the results with QoL of a normal age-matched reference population. Patients and methods: The study population was composed of 227 prostate cancer patients

  19. A Cross Sectional and Longitudinal Study of Pharmacy Student Perceptions of Readiness to Serve Diverse Populations.

    Science.gov (United States)

    Crawford, Stephanie Y; Awé, Clara; Tawk, Rima H; Simon Pickard, A

    2016-05-25

    Objective. To examine students' self-perceptions at different stages in a pharmacy curriculum of competence related to serving culturally diverse patients and to compare self-reported competence of a student cohort near the beginning and end of the degree program. Methods. Student perceptions across four pharmacy class years were measured in a cross-sectional survey, with a follow-up longitudinal survey of one cohort three years later. Results. Based on an 81.9% response rate (537/656), scores showed no attitude changes. Reported knowledge, skills, comfort in clinical encounters, and curricular preparedness increased across program years. Fourth-year (P4) pharmacy students reported the highest scores. Scores differed by gender, age, and race/ethnicity. Students in the fourth year scored lower on importance of diversity training. Conclusion. Improved perceptions of readiness (ie, knowledge and behavior) to serve diverse groups suggest the curriculum impacts these constructs, while the invariance of student attitudes and association of self-reports with programmatic outcomes warrant further investigation. PMID:27293229

  20. Emotional development in children with tics : a longitudinal population-based study

    NARCIS (Netherlands)

    Hoekstra, P. J.; Lundervold, A. J.; Lie, S. A.; Gillberg, C.; Plessen, Kerstin J.

    2013-01-01

    Children with tics often experience accompanying problems that may have more impact on their well being and quality of life than the tics themselves. The present study investigates characteristics and the course of associated problems. In a population-based follow-up study, we investigated the devel

  1. A Population-Based Longitudinal Study of Depression in Children with Developmental Disabilities in Manitoba

    Science.gov (United States)

    Shooshtari, Shahin; Brownell, Marni; Dik, Natalia; Chateau, Dan; Yu, C. T.; Mills, Rosemary S. L.; Burchill, Charles A.; Wetzel, Monika

    2014-01-01

    In this population-based study, prevalence of depression was estimated and compared between children with and without developmental disability (DD). Twelve years of administrative data were linked to identify a cohort of children with DD living in the Canadian province of Manitoba. Children in the study cohort were matched with children without DD…

  2. Risk Factors for Psychopathology in Children with Intellectual Disability: A Prospective Longitudinal Population-Based Study

    Science.gov (United States)

    Wallander, J. L.; Dekker, M. C.; Koot, H. M.

    2006-01-01

    Background: This study examined risk factors for the development of psychopathology in children with intellectual disability (ID) in the developmental, biological, family and social-ecological domains. Methods: A population sample of 968 children, aged 6-18, enrolled in special schools in the Netherlands for educable and trainable ID were assessed…

  3. Are School-SES Effects Statistical Artefacts? Evidence from Longitudinal Population Data

    Science.gov (United States)

    Marks, Gary N.

    2015-01-01

    Schools' socioeconomic status (SES) has been claimed as an important influence on student performance and there are calls for a policy response. However, there is an extensive literature which for various reasons casts doubt on the veracity of school-SES effects. This paper investigates school-SES effects with population data from a…

  4. Emotional development in children with tics: a longitudinal population-based study.

    Science.gov (United States)

    Hoekstra, P J; Lundervold, A J; Lie, S A; Gillberg, C; Plessen, Kerstin J

    2013-03-01

    Children with tics often experience accompanying problems that may have more impact on their well being and quality of life than the tics themselves. The present study investigates characteristics and the course of associated problems. In a population-based follow-up study, we investigated the developmental trajectory of children with and without tics when they were 7-9 years old. Parents and teachers completed the strengths and difficulties questionnaire (SDQ) when the children were 7-9 years (wave 1) and 4 years later (wave 2). Using strict criteria, we identified 38 children with tics in the cohort of 4,025 children (0.94% of the total cohort) with a preponderance of boys (78.9%). 22 children (57.9%) in the group with tics had only motor tics, and 16 (42.1%) had both motor and vocal tics. Children with tics had significantly higher parent- and teacher-rated SDQ total difficulty scores and subscale scores in both waves. Children with tics experienced an increase in emotional problems and in peer problems between the first and the second wave. This study in a general population indicates that the presence of tics is associated with a range of internalizing and externalizing difficulties, as well as problems in peer relationships. Moreover, our study indicates that emotional and peer problems tend to increase over time in the group of children with tics.

  5. Incidence and predictors of multimorbidity in the elderly: a population-based longitudinal study.

    Directory of Open Access Journals (Sweden)

    René Melis

    Full Text Available We aimed to calculate 3-year incidence of multimorbidity, defined as the development of two or more chronic diseases in a population of older people free from multimorbidity at baseline. Secondly, we aimed to identify predictors of incident multimorbidity amongst life-style related indicators, medical conditions and biomarkers.Data were gathered from 418 participants in the first follow up of the Kungsholmen Project (Stockholm, Sweden, 1991-1993, 78+ years old who were not affected by multimorbidity (149 had none disease and 269 one disease, including a social interview, a neuropsychological battery and a medical examination.After 3 years, 33.6% of participants who were without disease and 66.4% of those with one disease at baseline, developed multimorbidity: the incidence rate was 12.6 per 100 person-years (95% CI: 9.2-16.7 and 32.9 per 100 person-years (95% CI: 28.1-38.3, respectively. After adjustments, worse cognitive function (OR, 95% CI, for 1 point lower Mini-Mental State Examination: 1.22, 1.00-1.48 was associated with increased risk of multimorbidity among subjects with no disease at baseline. Higher age was the only predictor of multimorbidity in persons with one disease at baseline.Multimorbidity has a high incidence at old age. Mental health-related symptoms are likely predictors of multimorbidity, suggesting a strong impact of mental disorders on the health of older people.

  6. A Longitudinal Study of Symptoms of Oropharyngeal Dysphagia in an Elderly Community-Dwelling Population.

    Science.gov (United States)

    Nimmons, Danielle; Michou, Emilia; Jones, Maureen; Pendleton, Neil; Horan, Michael; Hamdy, Shaheen

    2016-08-01

    Dysphagia has been estimated to affect around 8-16 % of healthy elderly individuals living in the community. The present study investigated the stability of perceived dysphagia symptoms over a 3-year period and whether such symptoms predicted death outcomes. A population of 800 and 550 elderly community-dwelling individuals were sent the Sydney Swallow Questionnaire (SSQ) in 2009 and 2012, respectively, where an arbitrary score of 180 or more was chosen to indicate symptomatic dysphagia. The telephone interview cognitive screen measured cognitive performance and the Geriatric Depression Scale measured depression. Regression models were used to investigate associations with dysphagia symptom scores, cognition, depression, age, gender and a history of stroke; a paired t test was used to examine if individual mean scores had changed. A total of 528 participants were included in the analysis. In 2009, dysphagia was associated with age (P = 0.028, OR 1.07, CI 1.01, 1.13) and stroke (P = 0.046, OR 2.04, CI 1.01, 4.11) but these associations were no longer present in 2012. Those who had symptomatic dysphagia in 2009 (n = 75) showed a shift towards improvement in swallowing (P < 0.001, mean = -174.4, CI -243.6, -105.3), and for those who died from pneumonia, there was no association between the SSQ derived swallowing score and death (P = 0.509, OR 0.10, CI -0.41, -0.20). We conclude that swallowing symptoms are a temporally dynamic process, which increases our knowledge on swallowing in the elderly. PMID:27307155

  7. Fruit and vegetable consumption in adolescence and health in early adulthood: a longitudinal analysis of the Statistics Canada’s National Population Health Survey

    OpenAIRE

    Takaoka, Yuriko; Kawakami, Norito

    2013-01-01

    Background The present study aimed to explore a longitudinal relationship between fruit and vegetable consumption in adolescence and two health-related outcomes (i.e., self-rated health and mental health) in early adulthood in the community. Methods Data from a longitudinal cohort of the Canadian National Population Health Survey (NPHS) were used. Participants of the 2002/03 survey aged 15-17 years old were followed and surveyed in 2008/09. The number of the sample used in the statistical ana...

  8. A Population-Based and Longitudinal Study of Sexual Behavior and Multidrug-Resistant HIV Among Patients in Clinical Care

    Directory of Open Access Journals (Sweden)

    Kozal Michael J

    2006-06-01

    Full Text Available Abstract Background Population-based and longitudinal information regarding sexual risk behavior among patients with multidrug resistant (MDR HIV and their sexual partners is of great public health and clinical importance. Objective To characterize the HIV sexual risk behaviors of patients with and without drug-resistant HIV in the clinical care setting over time. Measurements 393 HIV-positive patients completed questionnaires of self-reported sexual risk behaviors at approximate 6-month intervals extending over 24 months. HIV viral load and genotypic drug resistance obtained during the same time points were matched to the behavioral data. Multidrug resistance was defined as having resistance to 2 or 3 antiretroviral (ARV drug classes. Results In serial cross-sectional analyses, 393 patients (44% female and 79% heterosexual contributed 919 matched behavioral and virologic results over the 24 months of data collection. Of these, 250 patients (64% reported having sex during at least 1 survey period resulting in greater than 10,000 sexual events with more than 1000 partners. Unprotected sexual behavior was reported by 45% of sexually active patients, resulting in 34% of all sex events that exposed 29% of all partners. Of these patients with unprotected sexual events, 31% had HIV drug resistance - 11.6% with resistance to 2 classes of ARVs (2-class, and 1.8% with 3-class ARV resistance at the time of a sexual risk event. Close to 1000 or 28% of all unprotected sexual events involved resistant strains (11% of these with resistance to 2 classes and 0.2% with 3-class resistance, exposing 20% of unprotected sexual partners to resistant HIV (8% to 2-class and 0.6% to 3-class resistance. In longitudinal analysis among the 78 patients who reported a cumulative total of 12 months of sexual history and had resistance testing, 38% reported engaging in unprotected sexual behavior. There was substantial and complex variation in the distribution of unprotected

  9. The importance of job characteristics in determining medical care-seeking in the Dutch working population, a longitudinal survey study

    Directory of Open Access Journals (Sweden)

    Steenbeek Romy

    2012-08-01

    Full Text Available Abstract Background The working population is ageing, which will increase the number of workers with chronic health complaints, and, as a consequence, the number of workers seeking health care. It is very important to understand factors that influence medical care-seeking in order to control the costs. I will investigate which work characteristics independently attribute to later care-seeking in order to find possibilities to prevent unnecessary or inefficient care-seeking. Methods Data were collected in a longitudinal two-wave study (n = 2305 workers. The outcome measures were visits (yes/no and frequency to a general practitioner (GP, a physical therapist, a medical specialist and/or a mental health professional. Multivariate regression analyses were carried out separately for men and women for workers with health complaints. Results In the Dutch working population, personal, health, and work characteristics, but not sickness absence, were associated with later care-seeking. Work characteristics independently attributed to medical care-seeking but only for men and only for the frequency of visits to the GP. Women experience more health complaints and seek health care more often than men. For women, experiencing a work handicap (health complaints that impede work performance was the only work characteristic associated with more care-seeking (GP. For men, work characteristics that led to less care-seeking were social support by colleagues (GP frequency, high levels of decision latitude (GP frequency and high levels of social support by the supervisor (medical specialist. Other work characteristics led to more care-seeking: high levels of engagement (GP, full time work (GP frequency and experiencing a work handicap (physical therapist. Conclusions We can conclude that personal and health characteristics are most important when explaining medical care-seeking in the Dutch working population. Work characteristics independently attributed to

  10. Increased risk of ischemic stroke in young patients with ankylosing spondylitis: a population-based longitudinal follow-up study.

    Directory of Open Access Journals (Sweden)

    Chia-Wei Lin

    Full Text Available BACKGROUND: Prospective data on the association between ischemic stroke and ankylosing spondylitis (AS in the young are sparse. The purpose of this population-based, age- and sex-matched longitudinal follow-up study was to investigate the risk of developing ischemic stroke in young patients with AS. METHODS: A total of 4562 patients aged 18- to 45-year-old with at least two ambulatory visits in 2001 with a principal diagnosis of AS were enrolled in the AS group. The non-AS group consisted of 22810 age- and sex-matched, randomly sampled subjects without AS. The two-year ischemic stroke-free survival rate for each group were calculated using the Kaplan-Meier method. Cox proportional hazards regression analysis was used to estimate the hazard ratio of ischemic stroke after adjusting for demographic and clinical covariates. RESULTS: During follow-up, 21 patients in the AS group and 53 in the non-AS group developed ischemic stroke. The ischemic stroke-free survival rate over the 2 year follow-up was lower in the AS group than the non-AS group (p = 0.0021. The crude hazard ratio of ischemic stroke for the AS group was 1.98 (95% CI, 1.20-3.29; p = 0.0079 and the adjusted hazard ratio after controlling for demographic and comorbid medical disorders was 1.93 (95% CI, 1.16-3.20; p = 0.0110. CONCLUSION: Our study showed an increased risk of developing ischemic stroke in young patients with AS.

  11. A longitudinal cohort based association study between uric acid level and metabolic syndrome in Chinese Han urban male population

    Directory of Open Access Journals (Sweden)

    Zhang Qian

    2012-06-01

    Full Text Available Abstract Background It has been recently demonstrated that serum uric acid (UA is associated with metabolic syndrome (MetS or its related clinical indications based on cross-sectional or prospective cohort studies. Nonetheless, due to the fact that UA level constantly fluctuates from time to time even for the person, using a single measure of UA level at baseline of those studies may not be sufficient for estimating the UA-Mets association. Methods To further estimate this time-dependent association, we fitted a generalized estimating equation (GEE regression model with data from a large-scale 6-year longitudinal study, which included 2222 participants aged > =25 years with an average of 3.5 repeated measures of UA per person in the Health Management Center of Shandong Provincial Hospital, Shandong, China. Results After adjusting for other potential confounding factors (i.e., total cholesterol, low-density lipoprotein, it was verified that time-dependent UA level was an independent risk factor for MetS (OR = 1.6920, p  Conclusions Serum UA level may serve as an important risk factor of MetS. Additionally, our study suggested that UA level be an independent risk factor to obesity, hypertension and dyslipidemia, but a protective factor to hyperglycemia. These findings are concordant with results from other studies on Asian populations, and jointly provide a basis to further develop a risk assessment model for predicting MetS using UA levels and other factors in China.

  12. Mental illness related disparities in diabetes prevalence, quality of care and outcomes: a population-based longitudinal study

    Directory of Open Access Journals (Sweden)

    Emery Jonathan D

    2011-11-01

    Full Text Available Abstract Background Health care disparity is a public health challenge. We compared the prevalence of diabetes, quality of care and outcomes between mental health clients (MHCs and non-MHCs. Methods This was a population-based longitudinal study of 139,208 MHCs and 294,180 matched non-MHCs in Western Australia (WA from 1990 to 2006, using linked data of mental health registry, electoral roll registrations, hospital admissions, emergency department attendances, deaths, and Medicare and pharmaceutical benefits claims. Diabetes was identified from hospital diagnoses, prescriptions and diabetes-specific primary care claims (17,045 MHCs, 26,626 non-MHCs. Both univariate and multivariate analyses adjusted for socio-demographic factors and case mix were performed to compare the outcome measures among MHCs, category of mental disorders and non-MHCs. Results The prevalence of diabetes was significantly higher in MHCs than in non-MHCs (crude age-sex-standardised point-prevalence of diabetes on 30 June 2006 in those aged ≥20 years, 9.3% vs 6.1%, respectively, P 1c, microalbuminuria, blood lipids was suboptimal in both groups, but was lower in MHCs (for all tests combined; adjusted OR 0.81, 95% CI 0.78 to 0.85, at one year; and adjusted rate ratio (RR 0.86, 95% CI 0.84 to 0.88, during the study period. MHCs also had increased risks of hospitalisation for diabetes complications (adjusted RR 1.20, 95% CI 1.17 to 1.24, diabetes-related mortality (1.43, 1.35 to 1.52 and all-cause mortality (1.47, 1.42 to 1.53. The disparities were most marked for alcohol/drug disorders, schizophrenia, affective disorders, other psychoses and personality disorders. Conclusions MHCs warrant special attention for primary and secondary prevention of diabetes, especially at the primary care level.

  13. A study of longitudinal data examining concomitance of pain and cognition in an elderly long-term care population

    Directory of Open Access Journals (Sweden)

    Burfield AH

    2012-03-01

    Full Text Available Allison H Burfield1, Thomas TH Wan2, Mary Lou Sole3, James W Cooper41Gerontology Program, School of Nursing, College of Health and Human Services, University of North Carolina, Charlotte, NC, USA; 2Health Services, Administration, and Medical Education, Director, Doctoral Program in Public Affairs, Associate Dean for Research, College of Health and Public Affairs, 3College of Nursing, University of Central Florida, Orlando, FL, USA; 4College of Pharmacy, University of Georgia, Athens, GA, USAPurpose: To examine if a concomitant relationship exists between cognition and pain in an elderly population residing in long-term care.Background/significance: Prior research has found that cognitive load mediates interpretation of a stimulus. In the presence of decreased cognitive capacity as with dementia, the relationship between cognition and increasing pain is unknown in the elderly.Patients and methods: Longitudinal cohort design. Data collected from the Minimum Data Set-Resident Assessment Instrument (MDS-RAI from the 2001–2003 annual assessments of nursing home residents. A covariance model was used to evaluate the relationship between cognition and pain at three intervals.Results: The sample included 56,494 subjects from nursing homes across the United States, with an average age of 83 ± 8.2 years. Analysis of variance scores (ANOVAs indicated a significant effect (P < 0.01 for pain and cognition, with protected t test revealing scores decreasing significantly with these two measures. Relative stability was found for pain and cognition over time. Greater stability was found in the cognitive measure than the pain measure. Cross-legged effects observed between cognition and pain measures were inconsistent. A concomitant relationship was not found between cognition and pain. Even though the relationship was significant at the 0.01 level, the correlations were low (r ≤ 0.08, indicating a weak association between cognition and pain

  14. Visual Impairment, Hearing Loss and Cognitive Function in an Older Population: Longitudinal Findings from the Blue Mountains Eye Study.

    Science.gov (United States)

    Hong, Thomas; Mitchell, Paul; Burlutsky, George; Liew, Gerald; Wang, Jie Jin

    2016-01-01

    The presence of visual impairment (VI) and hearing loss (HL) with may be a marker for subsequent cognitive decline over time in older people. A prospective, longitudinal population-based study of the 3654 participants of the Blue Mountains Eye Study were assessed for the associations between VI and HL and a decline in mini-mental state examination (MMSE) scores over a duration of 10 years from the 5-year (baseline of this report) to the 15-year follow-up visits. MMSE was assessed at the 5-, 10- and 15-year follow-up visits. A decline ≥3 scores from 5-year to 10- or 15-year visits indicated possible cognitive decline. VI was defined as best-corrected visual acuity 40 decibels in the worse-ear and dual sensory impairment (DSI) was defined by the co-presence of VI and HL, detected at 5-year follow-up (baseline of this report). Participants with no VI and HL over the same 5- or 10-year corresponding period were controls. Associations of VI, HL and DSI with possible cognitive decline were assessed using logistic regression models adjusting for age and sex after excluding subjects with a stroke history. The presence of VI, HL or DSI was not associated with possible cognitive decline over 5 years (odds ratio (OR) 0.84, 95% confidence-intervals (CI) 0.40-1.79, OR 1.02, 95% CI 0.61-1.70 and 1.41, 95% CI 0.54-3.72, respectively) or 10 years (OR 1.09, 95% CI 0.52-2.30, OR 1.09, 95% CI 0.65-1.82 and 1.15, 95% CI 0.28-4.73, respectively). There were no changes to these findings after adjustment for other potential confounders. Age was significantly associated with possible cognitive decline (OR 1.07, 95% CI 1.04-1.10 for both periods). Neither visual impairment, hearing loss nor dual sensory impairment was independently associated with subsequent decline in cognition. PMID:26808979

  15. Visual Impairment, Hearing Loss and Cognitive Function in an Older Population: Longitudinal Findings from the Blue Mountains Eye Study.

    Directory of Open Access Journals (Sweden)

    Thomas Hong

    Full Text Available The presence of visual impairment (VI and hearing loss (HL with may be a marker for subsequent cognitive decline over time in older people. A prospective, longitudinal population-based study of the 3654 participants of the Blue Mountains Eye Study were assessed for the associations between VI and HL and a decline in mini-mental state examination (MMSE scores over a duration of 10 years from the 5-year (baseline of this report to the 15-year follow-up visits. MMSE was assessed at the 5-, 10- and 15-year follow-up visits. A decline ≥3 scores from 5-year to 10- or 15-year visits indicated possible cognitive decline. VI was defined as best-corrected visual acuity 40 decibels in the worse-ear and dual sensory impairment (DSI was defined by the co-presence of VI and HL, detected at 5-year follow-up (baseline of this report. Participants with no VI and HL over the same 5- or 10-year corresponding period were controls. Associations of VI, HL and DSI with possible cognitive decline were assessed using logistic regression models adjusting for age and sex after excluding subjects with a stroke history. The presence of VI, HL or DSI was not associated with possible cognitive decline over 5 years (odds ratio (OR 0.84, 95% confidence-intervals (CI 0.40-1.79, OR 1.02, 95% CI 0.61-1.70 and 1.41, 95% CI 0.54-3.72, respectively or 10 years (OR 1.09, 95% CI 0.52-2.30, OR 1.09, 95% CI 0.65-1.82 and 1.15, 95% CI 0.28-4.73, respectively. There were no changes to these findings after adjustment for other potential confounders. Age was significantly associated with possible cognitive decline (OR 1.07, 95% CI 1.04-1.10 for both periods. Neither visual impairment, hearing loss nor dual sensory impairment was independently associated with subsequent decline in cognition.

  16. Individual and Neighborhood Socioeconomic Status and Healthcare Resources in Relation to Black-White Breast Cancer Survival Disparities

    Directory of Open Access Journals (Sweden)

    Tomi F. Akinyemiju

    2013-01-01

    Full Text Available Background. Breast cancer survival has improved significantly in the US in the past 10–15 years. However, disparities exist in breast cancer survival between black and white women. Purpose. To investigate the effect of county healthcare resources and SES as well as individual SES status on breast cancer survival disparities between black and white women. Methods. Data from 1,796 breast cancer cases were obtained from the Surveillance Epidemiology and End Results and the National Longitudinal Mortality Study dataset. Cox Proportional Hazards models were constructed accounting for clustering within counties. Three sequential Cox models were fit for each outcome including demographic variables; demographic and clinical variables; and finally demographic, clinical, and county-level variables. Results. In unadjusted analysis, black women had a 53% higher likelihood of dying of breast cancer and 32% higher likelihood of dying of any cause (P<0.05 compared with white women. Adjusting for demographic variables explained away the effect of race on breast cancer survival (HR, 1.40; 95% CI, 0.99–1.97, but not on all-cause mortality. The racial difference in all-cause survival disappeared only after adjusting for county-level variables (HR, 1.27; CI, 0.95–1.71. Conclusions. Improving equitable access to healthcare for all women in the US may help eliminate survival disparities between racial and socioeconomic groups.

  17. Associations between safety from crime, cycling, and obesity in a Dutch elderly population: results from the longitudinal aging study Amsterdam

    NARCIS (Netherlands)

    S.P.J. Kremers; G.J. de Bruijn; T.L.S. Visscher; D.J.H. Deeg; G.C.F. Thomése; M. Visser; W. van Mechelen; J. Brug

    2012-01-01

    The objective of this cross-sectional study was to investigate differences in associations between crime rates, cycling, and weight status between people living in low and high socioeconomic status (SES) neighbourhoods. In total, 470 participants in the Longitudinal Aging Study Amsterdam were includ

  18. Associations between Safety from Crime, Cycling, and Obesity in a Dutch Elderly Population: Results from the Longitudinal Aging Study Amsterdam

    OpenAIRE

    Kremers, Stef P. J.; Gert-Jan de Bruijn; Visscher, Tommy L. S.; Deeg, Dorly J. H.; G. C. Fleur Thomése; Marjolein Visser; Willem van Mechelen; Johannes Brug

    2012-01-01

    The objective of this cross-sectional study was to investigate differences in associations between crime rates, cycling, and weight status between people living in low and high socioeconomic status (SES) neighbourhoods. In total, 470 participants in the Longitudinal Aging Study Amsterdam were included (age: 63–70 y). Body height and weight were measured using a stadiometer and calibrated weight scale, respectively. Cycling behaviour was assessed in a face-to-face interview, and neighbourhood ...

  19. The developmental relationship between language and motor performance from 3 to 5 years of age: a prospective longitudinal population study

    OpenAIRE

    Wang, Mari Vaage; Lekhal, Ratib; Aarø, Leif Edvard; Holte, Arne; Schjølberg, Synnve

    2014-01-01

    Background: Previous research has found that language and motor skills are closely interrelated developmental areas. This observation has led to questions about the specificity of these domains, and the nature of the associations. In this study, we investigated the longitudinal relationship between language and gross and fine motor performance from 3 to 5 years of age. Methods: We tested the prediction across and within developmental domains using cross-lagged panel models. In ...

  20. Stimulant Use Trajectories and the Longitudinal Risk of Heavy Drinking: Findings From a Rural Population-Based Study

    Science.gov (United States)

    Booth, Brenda M.

    2012-01-01

    The extant literature offers little information about the longitudinal course of alcohol use among stimulant users, particularly those in rural areas, but it is plausible that reductions in stimulant use are accompanied by increases in heavy drinking. The objective of this study was to examine the longitudinal relationships between heavy drinking days and latent trajectories of powder cocaine, crack cocaine, and methamphetamine use. Participants (n = 710) were identified via Respondent-Driven Sampling in 3 rural communities in each of 3 states, with interviews conducted every 6 months over 3 years. Latent trajectory classes for powder cocaine, crack cocaine, and methamphetamine use were identified by conducting latent class growth analysis (LCGA). Generalized linear models (GLM) were conducted to examine how these latent classes were associated with the number of heavy drinking days in the past 30 days. Heavy drinking days did not significantly change over time when adjusting for covariates. Compared to those with a “fast low” trajectory of crack use, those with “steady high” and “declining” trajectories had more heavy drinking days. Compared to those with a “fast low” trajectory of powder cocaine use, those with a “steady moderate” trajectory had more heavy drinking days. Trajectories of methamphetamine use were not significantly associated with heavy drinking days. In conclusion, heavy alcohol use changes little over time among rural stimulant users. Many rural cocaine users could potentially benefit from interventions aimed at curtailing heavy drinking. PMID:22112423

  1. Maternal depressive symptoms across early childhood and asthma in school children: findings from a Longitudinal Australian Population Based Study.

    Directory of Open Access Journals (Sweden)

    Rebecca Giallo

    Full Text Available There is a growing body of evidence attesting to links between early life exposure to stress and childhood asthma. However, available evidence is largely based on small, genetically high risk samples. The aim of this study was to explore the associations between the course of maternal depressive symptoms across early childhood and childhood asthma in a nationally representative longitudinal cohort study of Australian children. Participants were 4164 children and their biological mothers from the Longitudinal Study of Australian Children. Latent class analysis identified three trajectories of maternal depressive symptoms across four biennial waves from the first postnatal year to when children were 6-7 years: minimal symptoms (74.6%, sub-clinical symptoms (20.8%, and persistent and increasing high symptoms (4.6%. Logistic regression analyses revealed that childhood asthma at age 6-7 years was associated with persistent and increasing high depressive symptoms after accounting for known risk factors including smoking during pregnancy and maternal history of asthma (adjusted OR 2.36, 95% CI 1.61-3.45, p.001. Our findings from a nationally representative sample of Australian children provide empirical support for a relationship between maternal depressive symptoms across the early childhood period and childhood asthma. The burden of disease from childhood asthma may be reduced by strengthening efforts to promote maternal mental health in the early years of parenting.

  2. Maternal depressive symptoms across early childhood and asthma in school children: findings from a Longitudinal Australian Population Based Study.

    Science.gov (United States)

    Giallo, Rebecca; Bahreinian, Salma; Brown, Stephanie; Cooklin, Amanda; Kingston, Dawn; Kozyrskyj, Anita

    2015-01-01

    There is a growing body of evidence attesting to links between early life exposure to stress and childhood asthma. However, available evidence is largely based on small, genetically high risk samples. The aim of this study was to explore the associations between the course of maternal depressive symptoms across early childhood and childhood asthma in a nationally representative longitudinal cohort study of Australian children. Participants were 4164 children and their biological mothers from the Longitudinal Study of Australian Children. Latent class analysis identified three trajectories of maternal depressive symptoms across four biennial waves from the first postnatal year to when children were 6-7 years: minimal symptoms (74.6%), sub-clinical symptoms (20.8%), and persistent and increasing high symptoms (4.6%). Logistic regression analyses revealed that childhood asthma at age 6-7 years was associated with persistent and increasing high depressive symptoms after accounting for known risk factors including smoking during pregnancy and maternal history of asthma (adjusted OR 2.36, 95% CI 1.61-3.45), p.001). Our findings from a nationally representative sample of Australian children provide empirical support for a relationship between maternal depressive symptoms across the early childhood period and childhood asthma. The burden of disease from childhood asthma may be reduced by strengthening efforts to promote maternal mental health in the early years of parenting.

  3. Who is maintaining weight in a middle-aged population in Sweden? A longitudinal analysis over 10 years

    Directory of Open Access Journals (Sweden)

    Wall Stig

    2007-06-01

    Full Text Available Abstract Background Obesity has primarily been addressed with interventions to promote weight loss and these have been largely unsuccessful. Primary prevention of obesity through support of weight maintenance may be a preferable strategy although to date this has not been the main focus of public health interventions. The aim of this study is to characterize who is not gaining weight during a 10 year period in Sweden. Methods Cross-sectional and longitudinal studies were conducted in adults aged 30, 40, 50 and 60 years during the Västerbotten Intervention Programme in Sweden. Height, weight, demographics and selected cardiovascular risk factors were collected on each participant. Prevalences of obesity were calculated for the 40, 50 and 60 year olds from the cross-sectional studies between 1990 and 2004. In the longitudinal study, 10-year non-gain (lost weight or maintained body weight within 3% of baseline weight or weight gain (≥ 3% was calculated for individuals aged 30, 40, or 50 years at baseline. A multivariate logistic regression model was built to predict weight non-gain. Results There were 82,927 adults included in the cross-sectional studies which had an average annual participation rate of 63%. Prevalence of obesity [body mass index (BMI in kg/m2 ≥ 30] increased from 9.4% in 1990 to 17.5% in 2004, and 60 year olds had the highest prevalence of obesity. 14,867 adults with a BMI of 18.5–29.9 at baseline participated in the longitudinal surveys which had a participation rate of 74%. 5242 adults (35.3% were categorized as non-gainers. Older age, being female, classified as overweight by baseline BMI, later survey year, baseline diagnosis of diabetes, and lack of snuff use increased the chances of not gaining weight. Conclusion Educational efforts should be broadened to include those adults who are usually considered to be at low risk for weight gain – younger individuals, those of normal body weight, and those without health

  4. Associations between Safety from Crime, Cycling, and Obesity in a Dutch Elderly Population: Results from the Longitudinal Aging Study Amsterdam

    Directory of Open Access Journals (Sweden)

    Stef P. J. Kremers

    2012-01-01

    Full Text Available The objective of this cross-sectional study was to investigate differences in associations between crime rates, cycling, and weight status between people living in low and high socioeconomic status (SES neighbourhoods. In total, 470 participants in the Longitudinal Aging Study Amsterdam were included (age: 63–70 y. Body height and weight were measured using a stadiometer and calibrated weight scale, respectively. Cycling behaviour was assessed in a face-to-face interview, and neighbourhood crime rates were assessed using data from police reports. Men residing in high SES neighbourhoods cycled more than males residing in low SES neighbourhoods. Cycling was negatively related to crime rates among both men and women living in low SES neighbourhoods. Among men living in low SES neighbourhoods, more cycling was associated with lower BMI. Interventions aiming to prevent obesity in older people may consider aiming at increasing bicycle use in lower SES neighbourhoods, but neighbourhood safety issues should be considered.

  5. Population size structure of non-native fishes along longitudinal gradients in a highly regulated Mediterranean basin.

    Directory of Open Access Journals (Sweden)

    Fátima Amat-Trigo

    2015-10-01

    Documented changes in fish size metrics at population levels can demonstrate trends in non-native fishes at basin scale, however, the collinearity with spatial gradients and the species-specific response could make it a difficult undertaking.

  6. Brain Amyloid Deposition and Longitudinal Cognitive Decline in Nondemented Older Subjects: Results from a Multi-Ethnic Population.

    Directory of Open Access Journals (Sweden)

    Yian Gu

    Full Text Available We aimed to whether the abnormally high amyloid-β (Aβ level in the brain among apparently healthy elders is related with subtle cognitive deficits and/or accelerated cognitive decline.A total of 116 dementia-free participants (mean age 84.5 years of the Washington Heights Inwood Columbia Aging Project completed 18F-Florbetaben PET imaging. Positive or negative cerebral Aβ deposition was assessed visually. Quantitative cerebral Aβ burden was calculated as the standardized uptake value ratio in pre-established regions of interest using cerebellar cortex as the reference region. Cognition was determined using a neuropsychological battery and selected tests scores were combined into four composite scores (memory, language, executive/speed, and visuospatial using exploratory factor analysis. We examined the relationship between cerebral Aβ level and longitudinal cognition change up to 20 years before the PET scan using latent growth curve models, controlling for age, education, ethnicity, and Apolipoprotein E (APOE genotype.Positive reading of Aβ was found in 41 of 116 (35% individuals. Cognitive scores at scan time was not related with Aβ. All cognitive scores declined over time. Aβ positive reading (B = -0.034, p = 0.02 and higher Aβ burden in temporal region (B = -0.080, p = 0.02 were associated with faster decline in executive/speed. Stratified analyses showed that higher Aβ deposition was associated with faster longitudinal declines in mean cognition, language, and executive/speed in African-Americans or in APOE ε4 carriers, and with faster memory decline in APOE ε4 carriers. The associations remained significant after excluding mild cognitive impairment participants.High Aβ deposition in healthy elders was associated with decline in executive/speed in the decade before neuroimaging, and the association was observed primarily in African-Americans and APOE ε4 carriers. Our results suggest that measuring cerebral Aβ may give us

  7. The longitudinal relationship of changes of adiposity to changes in pulmonary function and risk of asthma in a general adult population

    DEFF Research Database (Denmark)

    Fenger, Runa Vavia; Gonzalez-Quintela, Arturo; Vidal, Carmen;

    2014-01-01

    to changes in forced expiratory volume in first second (FEV1) and forced vital capacity (FVC), as well as to incident cases of asthma and wheezing, according to atopy and gender. METHODS: A general population sample aged 19-72 years was examined with the same methodology five years apart. Longitudinal...... prior to adiposity changes were examined as potential effect modifiers. RESULTS: A total of 2,308 persons participated in both baseline and five-year follow-up examinations. Over the entire span of adiposity changes, adiposity gain was associated with decreasing levels of lung function, whereas...... not modify these associations. There were no statistically significant associations between changes in adiposity measures and risk of incident asthma or wheeze. CONCLUSIONS: Over a five-year period, increasing adiposity was associated with decreasing lung function, whereas decreasing adiposity was associated...

  8. Same-Sex Couples' Decisions and Experiences of Marriage in the Context of Minority Stress: Interviews From a Population-Based Longitudinal Study.

    Science.gov (United States)

    Rostosky, Sharon S; Riggle, Ellen D B; Rothblum, Esther D; Balsam, Kimberly F

    2016-08-01

    In the emerging context of marriage equality, it is important to explore the reasons for and experience of marriage for long-term same-sex couples, including the role of minority stress. In Wave 3 of the population-based, longitudinal CUPPLES Study we interviewed 21 long-term same-sex couples (14 female, 7 male) who resided in 12 different states and who were legally married. Couple members ranged in age from 37 to 84 and reported being together as a couple from 15 to 41 years. Seven couples lived in states that did not recognize their marriage at the time of the interview. Legal protection and social validation emerged as the two primary domains that captured couples' lived experiences of marriage. Minority stress experiences emerged in the narratives in the context of couples' long-term commitment, the availability of civil marriage, and couples' participation in activist efforts on behalf of marriage equality for themselves and others.

  9. Genetic association study with metabolic syndrome and metabolic-related traits in a cross-sectional sample and a 10-year longitudinal sample of chinese elderly population.

    Directory of Open Access Journals (Sweden)

    Jinghui Yang

    Full Text Available BACKGROUND: The metabolic syndrome (MetS has been known as partly heritable, while the number of genetic studies on MetS and metabolic-related traits among Chinese elderly was limited. METHODS: A cross-sectional analysis was performed among 2 014 aged participants from September 2009 to June 2010 in Beijing, China. An additional longitudinal study was carried out among the same study population from 2001 to 2010. Biochemical profile and anthropometric parameters of all the participants were measured. The associations of 23 SNPs located within 17 candidate genes (MTHFR, PPARγ, LPL, INSIG, TCF7L2, FTO, KCNJ11, JAZF1, CDKN2A/B, ADIPOQ, WFS1, CDKAL1, IGF2BP2, KCNQ1, MTNR1B, IRS1, ACE with overweight and obesity, diabetes, metabolic phenotypes, and MetS were examined in both studies. RESULTS: In this Chinese elderly population, prevalence of overweight, central obesity, diabetes, dyslipidemia, hypertension, and MetS were 48.3%, 71.0%, 32.4%, 75.7%, 68.3% and 54.5%, respectively. In the cross-sectional analyses, no SNP was found to be associated with MetS. Genotype TT of SNP rs4402960 within the gene IGF2BP2 was associated with overweight (odds ratio (OR  = 0.479, 95% confidence interval (CI: 0.316-0.724, p = 0.001 and genotype CA of SNP rs1801131 within the gene MTHFR was associated with hypertension (OR = 1.560, 95% CI: 1.194-2.240, p = 0.001. However, these associations were not observed in the longitudinal analyses. CONCLUSIONS: The associations of SNP rs4402960 with overweight as well as the association of SNP rs1801131 with hypertension were found to be statistically significant. No SNP was identified to be associated with MetS in our study with statistical significance.

  10. Associations between cognitive abilities and life satisfaction in the oldest-old. Results from the longitudinal population study Good Aging in Skåne

    Directory of Open Access Journals (Sweden)

    Enkvist Å

    2013-07-01

    Full Text Available Åsa Enkvist, Henrik Ekström, Sölve Elmståhl Department of Health Sciences, Division of Geriatric Medicine, Lund University, Skåne University Hospital, Malmö, Sweden Introduction: Studies on the associations between cognitive abilities and life satisfaction (LS in the oldest-old are few. The aim of this study was to explore whether abilities in six different cognitive domains could predict LS in the oldest-old 3 years later. Methods: The study population consisted of 681 individuals aged 78–98 years, drawn from the longitudinal population study “Good Aging in Skåne,” which is part of a national survey (The Swedish National Study on Aging and Care. Scores on 13 cognitive tests were related to scores on Neugartens’ LS index A (LSI-A 3 years later. The cognitive tests were added into six different cognitive domains. A multiple regression analysis was constructed for each cognitive domain separately, with scores on the LSI-A as the dependent variable. The model was adjusted stepwise for sex, age, education, functional capacity, and depressive mood. Results: Significant correlations were found between digit cancellation, word recall, verbal fluency (VF A, VF animals, VF occupations, and mental rotations at baseline, as well as LSI-A at follow-up. The domains of spatial abilities (B = 0.453, P = 0.014 and processing speed (B = 0.118, P = 0.020 remained significantly associated with LSI-A 3 years later after adjustment. Conclusion: The cognitive domains of spatial abilities and processing speed predicted LS 3 years later in the oldest-old. Clinical implications are discussed. Keywords: oldest-old, life satisfaction, longitudinal, crystallized and fluid intelligence, cognition

  11. From epidemiology to daily life: linking daily life stress reactivity to persistence of psychotic experiences in a longitudinal general population study.

    Directory of Open Access Journals (Sweden)

    Dina Collip

    Full Text Available Subclinical psychotic experiences at the level of the general population are common, forming an extended psychosis phenotype with clinical psychosis. Persistence of subclinical experiences is associated with transition to later mental disorder. Increased daily life stress reactivity is considered an endophenotype for psychotic disorders. We examined, in a longitudinal framework, whether baseline momentary assessment markers of stress reactivity would predict persistence of subclinical psychotic experiences over time. In a general population sample of female twins (N = 566, the Experience Sampling Method (ESM; repetitive random sampling of momentary emotions, psychotic experiences and context was used to assess (emotional and psychotic daily life stress reactivity. Persistence of subclinical psychotic experiences was based on the Community Assessment of Psychic Experiences (CAPE, assessed three times over 14 months post-baseline. It was investigated whether baseline daily life emotional and psychotic stress reactivity predicted persistence of psychotic experiences over time. Higher levels of emotional stress reactivity (a decrease in positive and an increase in negative affect in response to stress, and increased psychotic reactivity to daily stress was found in individuals with persistent psychotic experiences over time compared to individuals with transient psychotic experiences. The results suggest that markers of daily life stress reactivity may predict "macro-level" persistence of normally transient expression of psychotic liability over time. Linking daily life markers of altered reactivity in terms of emotions and psychotic experiences to longitudinal persistence of psychotic experiences, associated with increased risk of transition to overt mental disorder, may contribute to earlier and more accurate diagnosis of risk.

  12. Life satisfaction (LS) and symptoms among the oldest-old: results from the longitudinal population study called Good Aging in Skåne (GÅS).

    Science.gov (United States)

    Enkvist, Asa; Ekström, Henrik; Elmståhl, Sölve

    2012-01-01

    Studies on the prevalence of symptoms in the general population and its' relation to LS in the oldest-old are to our knowledge non-existent. The aim of this study was to describe the frequency and experienced severity of elderly subjects' reported symptoms and how symptoms are related to LS. The study population consisted of 681 individuals aged 78-93 years, drawn from the longitudinal population study, GÅS, part of a national survey (SNAC). Scores on the life satisfaction index were related to scores on a modified version of the Göteborg Quality of Life (GQoL) instrument, covering 32 common symptoms. Musculo-skeletal symptoms like pain were reported by 74%, 80% had depressive symptoms and 68% general fatigue. Less than 6% of men and women reported no metabolic symptoms or symptoms related to the head. In a multiple regression model it was shown that four groups of symptoms could significantly predict LS 3 years later: depression, tension, GI-symptoms and musculo-skeletal symptoms. The clinical implication of this study is that careful attention should be paid to the elderly patients' complaints concerning symptoms in the above areas since this has the potential to significantly increase the patients' satisfaction with life.

  13. Associations between functional ability and life satisfaction in the oldest old: results from the longitudinal population study Good Aging in Skåne

    Directory of Open Access Journals (Sweden)

    Enkvist Å

    2012-08-01

    Full Text Available Åsa Enkvist, Henrik Ekström, Sölve ElmståhlDepartment of Health Sciences, Lund University, Malmö University Hospital, Malmö, SwedenObjectives: To describe change in functional ability in the oldest-old population during 3 years and examine its relation to life satisfaction (LS. A total of 681 individuals aged 78 and older from the population-based study Good Aging in Skåne took part.Methods: Functional ability was assessed using Sonn and Åsberg's Activities of Daily Living (ADL scale and related to LS assessed by Neugarten et al's Life Satisfaction Index A (LSI-A.Results: Fifty-one percent of 87–93-year-olds reported ADL decline during 3 years. Individuals reporting impaired ADL had a mean LSI-A value of 23.0 compared to 26.4 in those unchanged. ADL decline had a stronger negative effect on LS in the younger group (78–84 years, r = 0.207, P < 0.001. In a multiple regression model, one score's decline in ADL capacity corresponded to 1.5 scores lower LS (P < 0.001.Discussion: Effort put into keeping the oldest old on a high level of functional ability has the potential to maintain the LS of this population.Keywords: life satisfaction, functional ability, longitudinal, oldest old

  14. Binge eating, purging and non-purging compensatory behaviours decrease from adolescence to adulthood: A population-based, longitudinal study

    Directory of Open Access Journals (Sweden)

    Abebe Dawit

    2012-01-01

    Full Text Available Abstract Background Subclinical forms of eating disorders (ED are highly prevalent, but relatively little is known about age trends, gender differences and distinctions among symptoms. This study investigates age trends and gender difference in binge eating, purging and non-purging compensatory behaviours (CB and the relationship of such behaviours to psychosocial problems. Methods Data from the national representative longitudinal study "Young in Norway" (ages 14-34 years were analysed using χ2 tests, logistic random intercept models and analyses of covariance. Results For both genders, a decrease was found in the prevalence of CB from age 14-16 years to 23 years and over. For binging, however, a significant decrease was found only for females, whose binge eating also declined more markedly over time than did males'. A significant gender difference was detected for purging, with females at higher risk. Purging was related to particularly serious symptoms of psychosocial problems: Those who purged had significantly higher levels of appearance dissatisfaction, anxiety and depressive symptoms, alcohol consumption, self-concept instability and loneliness than those with symptoms of other forms of disordered eating. Conclusions Individuals affected by purging need to be targeted as a high-risk group. The distinction in severity among the subclinical ED may indicate the need for the reformulation of the eating disorder not otherwise specified category in the Diagnostic and Statistical Manual of Mental Disorders-V.

  15. The relationship between social functioning and subjective memory complaints in older persons : a population-based longitudinal cohort study

    NARCIS (Netherlands)

    Kuiper, Jisca S; Oude Voshaar, Richard C; Zuidema, Sytse U; Stolk, Ronald P; Zuidersma, Marij; Smidt, Nynke

    2016-01-01

    OBJECTIVE: Poor social functioning is associated with cognitive decline in older adults. It is unclear whether social functioning is also associated with subjective memory complaints (SMC). We investigated the association between social functioning and incident SMC and SMC recovery. METHODS: A popul

  16. Prevalence of Tourette Syndrome and Chronic Tics in the Population-Based Avon Longitudinal Study of Parents and Children Cohort

    Science.gov (United States)

    Scharf, Jeremiah M.; Miller, Laura L.; Mathews, Carol A.; Ben-Shlomo, Yoav

    2012-01-01

    Objective: Recent epidemiologic studies have demonstrated that Tourette syndrome (TS) and chronic tic disorder (CT) are more common than previously recognized. However, few population-based studies have examined the prevalence of co-occurring neuropsychiatric conditions such as obsessive-compulsive disorder (OCD) and…

  17. Longitudinal associations between physical load and chronic low back pain in the general population: the Doetichem Cohort Study

    NARCIS (Netherlands)

    Oostrom, S.H.; Verschuren, M.; Vet, de H.C.; Boshuizen, H.C.; Picavet, H.S.

    2012-01-01

    Study Design. Prospective cohort study. Objective. We explored long-term associations between physical load exposure and chronic low back pain (LBP) using data from an ongoing population-based cohort study. Summary of Background Data. Physical load in work or daily life is often studied in relation

  18. Population model of longitudinal FEV1 data in asthmatics: meta-analysis and predictability of placebo response.

    Science.gov (United States)

    Marostica, Eleonora; Russu, Alberto; Yang, Shuying; De Nicolao, Giuseppe; Zamuner, Stefano; Beerahee, Misba

    2014-12-01

    Asthma is an obstructive lung disease where the mechanism of disease progression is not fully understood hence motivating the use of empirical models to describe the evolution of the patient's health state. With reference to placebo response, measured in terms of FEV1 (Forced Expiratory Volume in 1 s), a range of empirical models taken from the literature were compared at a single trial level. In particular, eleven GSK trials lasting 12 weeks in mild-to-moderate asthma were used for the modelling of longitudinal placebo responses. Then, the chosen exponential model was used to carry out an individual participant data meta-analysis on eleven trials. A covariate analysis was also performed to find relevant covariates in asthma to be accounted for in the meta-analysis model. Age, gender, and height were found statistically significant (e.g. the taller the patients the higher the FEV1, the older the patients the lower the FEV1, and females have lower FEV1). By truncating each trial at week 4, the predictive properties of the meta-analysis model were also investigated, showing its ability to predict long-term FEV1 response from truncated trials. Summarizing, the study suggests that: (i) the exponential model effectively describes the placebo response; (ii) the meta-analysis approach may prove helpful to simulate new trials as well as to reduce trial duration in view of its predictive properties; (iii) the inclusion of available covariates within the meta-analysis model provides a reduction of the inter-individual variability.

  19. Neuropsychological Decline in Schizophrenia from the Premorbid to Post-Onset Period: Evidence from a Population-Representative Longitudinal Study

    Science.gov (United States)

    Meier, Madeline H.; Caspi, Avshalom; Reichenberg, Abraham; Keefe, Richard S.E.; Fisher, Helen; Harrington, HonaLee; Houts, Renate; Poulton, Richie; Moffitt, Terrie

    2013-01-01

    Objective Despite widespread belief that neuropsychological decline is a cardinal feature of the progression from the premorbid to the chronic form of schizophrenia, few longitudinal studies have examined change in neuropsychological functioning from before to after the onset of schizophrenia. We addressed the following unresolved questions: Is neuropsychological decline generalized versus confined to particular mental functions? Is neuropsychological decline unique to schizophrenia? Do individuals with schizophrenia also have cognitive problems in everyday life? Method Participants were members of a representative cohort of 1,037 individuals born in Dunedin, New Zealand between 1972-73 and followed prospectively to age 38, with 95% retention. Assessment of IQ and other specific neuropsychological functions was conducted at ages 7-13, before the onset of schizophrenia, and again at age 38. Informants also reported on cognitive problems at age 38. Results Individuals with schizophrenia showed decline in IQ as well as a range of different mental functions, particularly those tapping processing speed, learning, executive functioning, and motor functioning. There was little evidence of decline in verbal abilities or delayed memory, however, and the developmental progression of deficits in schizophrenia differed across mental functions. Processing speed deficits increased gradually from childhood to beyond the early teen years, whereas verbal deficits emerged early but remained static through midlife. Neuropsychological decline was specific to schizophrenia, as no evidence of decline was apparent among individuals with persistent depression, children with mild cognitive impairment, individuals matched on childhood risk factors for schizophrenia, and psychiatrically healthy individuals. Informants also reported cognitive problems for individuals diagnosed with schizophrenia. Conclusion There is substantial neuropsychological decline in schizophrenia from the premorbid to

  20. The Black-White Achievement Gap Revisited Revisitando la brecha en el rendimiento de estudiantes negros y blancos Revisitando a defasagem de rendimento academico dos estudantes negros e brancos

    Directory of Open Access Journals (Sweden)

    Henry Braun

    2010-09-01

    Full Text Available This study examines trends in Black student achievement and in the Black-White achievement gap over the period 2000 to 2007, employing data from ten states drawn from the NAEP Grade 8 mathematics assessments. Results are obtained for three levels of aggregation: the state, school poverty stratum within the state, and schools within poverty stratum. In addition, information on the ten states’ education policies for the period 1998 to 2005 was compiled. States relative ranks on the overall strength of their reform efforts were compared to their relative ranks with respect to their success in improving Black student achievement and in reducing the Black- White achievement gap. This study constitutes an extension of earlier work that considered the same issues for the period 1992 to 2000 and, thus, offers a unique comparison between the pre-NCLB era and the present one. Although the ten states certainly differed in their outcomes, the general picture at all three levels of aggregation is quite clear: The achievement gaps are substantial and the introduction of federally mandated high stakes test-based accountability through No Child Left Behind has had a very modest impact on the rates of improvement for Black students and on the pace of reductions in the achievement gaps between Black students and White students. Moreover, there was only a weak association between states’ policy rankings and their rankings related to test results. It appears there is a need for both fresh thinking on education reform and a more concerted effort to collect comprehensive longitudinal information on states' education policies.
    Este estudio examina las tendencias en el rendimiento académico de estudiantes negros y la brecha en el rendimiento de los estudiantes negros y blancos en el período 2000 a 2007, utilizando datos de las evaluaciones NAEP de Matemáticas para el octavo grado en diez estados. Se obtuvieron resultados para tres niveles de agregacio

  1. Natural History of Dependency in the Elderly: A 24-Year Population-Based Study Using a Longitudinal Item Response Theory Model.

    Science.gov (United States)

    Edjolo, Arlette; Proust-Lima, Cécile; Delva, Fleur; Dartigues, Jean-François; Pérès, Karine

    2016-02-15

    We aimed to describe the hierarchical structure of Instrumental Activities of Daily Living (IADL) and basic Activities of Daily Living (ADL) and trajectories of dependency before death in an elderly population using item response theory methodology. Data were obtained from a population-based French cohort study, the Personnes Agées QUID (PAQUID) Study, of persons aged ≥65 years at baseline in 1988 who were recruited from 75 randomly selected areas in Gironde and Dordogne. We evaluated IADL and ADL data collected at home every 2-3 years over a 24-year period (1988-2012) for 3,238 deceased participants (43.9% men). We used a longitudinal item response theory model to investigate the item sequence of 11 IADL and ADL combined into a single scale and functional trajectories adjusted for education, sex, and age at death. The findings confirmed the earliest losses in IADL (shopping, transporting, finances) at the partial limitation level, and then an overlapping of concomitant IADL and ADL, with bathing and dressing being the earliest ADL losses, and finally total losses for toileting, continence, eating, and transferring. Functional trajectories were sex-specific, with a benefit of high education that persisted until death in men but was only transient in women. An in-depth understanding of this sequence provides an early warning of functional decline for better adaptation of medical and social care in the elderly.

  2. Evaluation of the Finnish Diabetes Risk Score to predict type 2 diabetes mellitus in a Colombian population: A longitudinal observational study

    Institute of Scientific and Technical Information of China (English)

    Diego; Gomez-Arbelaez; Laura; Alvarado-Jurado; Miguel; Ayala-Castillo; Leonardo; Forero-Naranjo; Paul; Anthony; Camacho; Patricio; Lopez-Jaramillo

    2015-01-01

    AIM: To assess the performance of the Finnish Diabetes Risk Score(FINDRISC) questionnaire for detecting and predicting type 2 diabetes mellitus(DM2) in a Colombian population.METHODS: This is a longitudinal observational study conducted in Floridablanca, Colombia. Adult subjects(age ≥ 35 years) without known diabetes, were included. A modified version of FINDRISC was completed, and the glycemia values from all the subjects were collected from the hospital’s database. Firstly, a cross-sectional analysis was performed and then, the subsample of prediabetic participants was followed for diabetes incidence. RESULTS: A total of 772 subjects were suitable for the study. The overall prevalence of undiagnosed DM2 was 2.59%, and the incidence of DM2 among the prediabetic participants was 7.5 per 100 person-years after a total of 265257 person-years follow-up. The FINDRISC at baseline was significantly associated with undiagnosed and incident DM2. The area under receiver operating characteristics curve of the FINDRISC score for detecting undiagnosed DM2 in both men and women was 0.7477 and 0.7175, respectively; and for predicting the incidence of DM2 among prediabetics was 71.99% in men and 67.74% in women. CONCLUSION: The FINDRISC questionnaire is a useful screening tool to identify cross-sectionally unknown DM2 and to predict the incidence of DM2 among prediabetics in the Colombian population.

  3. Natural History of Dependency in the Elderly: A 24-Year Population-Based Study Using a Longitudinal Item Response Theory Model.

    Science.gov (United States)

    Edjolo, Arlette; Proust-Lima, Cécile; Delva, Fleur; Dartigues, Jean-François; Pérès, Karine

    2016-02-15

    We aimed to describe the hierarchical structure of Instrumental Activities of Daily Living (IADL) and basic Activities of Daily Living (ADL) and trajectories of dependency before death in an elderly population using item response theory methodology. Data were obtained from a population-based French cohort study, the Personnes Agées QUID (PAQUID) Study, of persons aged ≥65 years at baseline in 1988 who were recruited from 75 randomly selected areas in Gironde and Dordogne. We evaluated IADL and ADL data collected at home every 2-3 years over a 24-year period (1988-2012) for 3,238 deceased participants (43.9% men). We used a longitudinal item response theory model to investigate the item sequence of 11 IADL and ADL combined into a single scale and functional trajectories adjusted for education, sex, and age at death. The findings confirmed the earliest losses in IADL (shopping, transporting, finances) at the partial limitation level, and then an overlapping of concomitant IADL and ADL, with bathing and dressing being the earliest ADL losses, and finally total losses for toileting, continence, eating, and transferring. Functional trajectories were sex-specific, with a benefit of high education that persisted until death in men but was only transient in women. An in-depth understanding of this sequence provides an early warning of functional decline for better adaptation of medical and social care in the elderly. PMID:26825927

  4. The association of cancer survival with four socioeconomic indicators: a longitudinal study of the older population of England and Wales 1981–2000

    Directory of Open Access Journals (Sweden)

    Young Harriet

    2007-01-01

    Full Text Available Abstract Background Many studies have found socioeconomic differentials in cancer survival. Previous studies have generally demonstrated poorer cancer survival with decreasing socioeconomic status but mostly used only ecological measures of status and analytical methods estimating simple survival. This study investigate socio-economic differentials in cancer survival using four indicators of socioeconomic status; three individual and one ecological. It uses a relative survival method which gives a measure of excess mortality due to cancer. Methods This study uses prospective record linkage data from The Office for National Statistics Longitudinal Study for England and Wales. The participants are Longitudinal Study members, recorded at census in 1971 and 1981 and with a primary malignant cancer diagnosed at age 45 or above, between 1981 and 1997, with follow-up until end 2000. The outcome measure is relative survival/excess mortality, compared with age and sex adjusted survival of the general population. Relative survival and Poisson regression analyses are presented, giving models of relative excess mortality, adjusted for covariates. Results Different socioeconomic indicators detect survival differentials of varying magnitude and definition. For all cancers combined, the four indicators show similar effects. For individual cancers there are differences between indicators. Where there is an association, all indicators show poorer survival with lower socioeconomic status. Conclusion Cancer survival differs markedly by socio-economic status. The commonly used ecological measure, the Carstairs Index, is adequate at demonstrating socioeconomic differentials in survival for combined cancers and some individual cancers. A combination of car access and housing tenure is more sensitive than the ecological Carstairs measure at detecting socioeconomic effects on survival – confirming Carstairs effects where they occur but additionally identifying

  5. Homofilia, Selección e Influencia en un Estudio Longitudinal de Drogas en Población Escolar Homophily, Selection, and Influence in a Longitudinal Study of Drugs in School Population

    Directory of Open Access Journals (Sweden)

    Eduardo Valenzuela

    2011-11-01

    Full Text Available Este estudio pretende establecer los niveles de homogeneidad de pares -a veces llamada homofilia en la literatura especializada- que se encuentra en el uso de tabaco, alcohol y marihuana en relaciones de amistad en la adolescencia temprana. Se utilizan datos longitudinales que identifican diadas de amistad entre alumnos de 7° y 8° grado provenientes de una muestra representativa de población escolarizada de la Región Metropolitana de Chile. También se ofrecen estimaciones sobre el origen de la homofilia observada, sea como resultado de procesos de selección, en los que la similitud precede a la amistad, o de influencia, en la que, por el contrario, la amistad conduce a la concordancia de pares. Los resultados muestran que la iniciación en el uso de drogas se realiza en ambientes moderadamente concordantes y que los efectos de influencia predominan sobre los de selección.This study seeks to establish levels of peer homogeneity -sometimes called homophily in the literature- in the use of tobacco, alcohol, and marijuana in friendship relations in early adolescence. Longitudinal data from a representative sample of school population of the Metropolitan Region of Chile was used to identify friendship dyads between students in 7th and 8th grades. Additionally, some estimates about the origin of the observed homophily are provided, as a result of selection processes in which similarity precedes friendship or, alternatively, as a result of influence processes where friendship leads to matching pairs. The results show that initiation into drugs takes place in environments that are moderately homogeneous and that influence effects are more important than selection effects.

  6. Parental gender equality and use of oral contraceptives among young women: A longitudinal, population-based study in Sweden

    Directory of Open Access Journals (Sweden)

    Mamunur Rashid

    2014-01-01

    Full Text Available Background: Little is known about how parental gender equality early in their children lives can influence daughters′ decision to use contraceptive pills. Aim: The study aimed at exploring whether maternal working time and paternity leave in Sweden during the first two years of their daughters′ lives is associated with the use of oral contraceptives when they are adolescents or young adults. Materials and Methods: The study population was selected from a cohort of all Swedish fathers and mothers who had their first child together between 1988 and 1989 (n = 57,520 family units. Multivariate logistic regression was used to estimate the association. Results: Mothers′ longer working time was mildly associated with daughters′ oral contraceptive pill use, though no clear trend was observed. Longer paternity leave periods (>30 days were not associated with use of oral contraceptives among their daughters, but 1-30 day periods showed a mild positive association. Conclusion: For maternal working time, there seems to be an association, but trends by working hours are not clear. There is no clear association between paternity leave during the first two years of their daughters′ life and the use of oral contraceptives when they are adolescents and young adults.

  7. Comparison of stayers, dropouts, and newcomers in a longitudinal population study of asthma and bronchial hyperresponsiveness: introduction of bias?

    Science.gov (United States)

    Ulrik, C S

    1995-01-01

    A random sample of children and adolescents from the general population in Copenhagen, Denmark, has been examined twice (6 years apart) with respect to asthma, allergy, and nonspecific bronchial hyperresponsiveness. To investigate potential bias resulting from loss of baseline subjects at follow-up (dropout bias) and bias resulting from subjects entering the study at the follow-up stage (newcomer bias), stayers (subjects who participated in both examinations) were compared to dropouts and newcomers, respectively. The sample consisted of 983 subjects (aged 7-17 years at the time of the baseline study), of whom 408 (199 boys) participated in both examinations (stayers), 119 (62 boys) in the baseline study only (dropouts), and 257 (124 boys in the follow-up study only (newcomers). Thus, a total of 784 subjects (80% of the sample) were examined either once or twice. At baseline dropouts did not differ from stayers with respect to anthropometric data, smoking habits, pulmonary function, or prevalence of positive skin prick tests, bronchial hyperresponsiveness, asthma, and allergic diseases. Likewise, these variables for newcomers were not different from those of the stayers apart from a significantly higher smoking rate in newcomers (45% vs. 32%, p = 0.003). Based on these findings and the high overall response rate, it seems reasonable to assume that the group of stayers is representative of the whole sample, apart from an underestimation of the number of smokers and, therefore, an underestimation of the risks associated with smoking.(ABSTRACT TRUNCATED AT 250 WORDS)

  8. Asthma Is Associated With a Subsequent Risk of Peripheral Artery Disease: A Longitudinal Population-Based Study.

    Science.gov (United States)

    Yao, Chih-Wei; Shen, Te-Chun; Lu, Chiung-Ray; Wang, Yu-Chiao; Lin, Cheng-Li; Tu, Chih-Yen; Hsia, Te-Chun; Shih, Chuen-Ming; Hsu, Wu-Huei; Sung, Fung-Chang

    2016-01-01

    Asthma has been associated with the atherosclerosis risk, but not clear of peripheral artery disease (PAD). We attempted to examine the risk of PAD in patients with asthma.From the insurance claims data of Taiwan, we identified 28,158 newly diagnosed asthma patients in 2000 to 2005 and 56,316 persons without asthma randomly selected into the comparison cohort, frequency matched by sex, age, and the date of diagnosis. Both cohorts were followed up until the end of 2011 to estimate the incident PAD. Adjusted hazard ratios (aHRs) of PAD were estimated using the Cox proportional hazards model after controlling for sex, age, and comorbidities.The incidence of PAD was 1.46 times higher in the asthma cohort than in the comparison cohort, with an aHR of 1.34 [95% confidence interval (CI) = 1.24-1.45]. Incidence of PAD was higher in men, the aged, and those with comorbidities in both cohorts. The aHRs of PAD remained significant for the asthma cohort in all subgroups of sex, age, and the presence of comorbidity. The aHRs of PAD were 14.1 (95% CI = 8.18-24.5) in asthma patients with multiple emergency visits and 22.3 (95% CI = 15.6-31.9) for those with multiple hospitalizations.Although smoking is a potential confounding factor, this study suggests patients with asthma have a significantly higher risk of developing PAD than the general population. The results also support the notion that poor control of asthma status is a key factor in subsequent PAD development. PMID:26817901

  9. Same-Sex Couples' Decisions and Experiences of Marriage in the Context of Minority Stress: Interviews From a Population-Based Longitudinal Study.

    Science.gov (United States)

    Rostosky, Sharon S; Riggle, Ellen D B; Rothblum, Esther D; Balsam, Kimberly F

    2016-08-01

    In the emerging context of marriage equality, it is important to explore the reasons for and experience of marriage for long-term same-sex couples, including the role of minority stress. In Wave 3 of the population-based, longitudinal CUPPLES Study we interviewed 21 long-term same-sex couples (14 female, 7 male) who resided in 12 different states and who were legally married. Couple members ranged in age from 37 to 84 and reported being together as a couple from 15 to 41 years. Seven couples lived in states that did not recognize their marriage at the time of the interview. Legal protection and social validation emerged as the two primary domains that captured couples' lived experiences of marriage. Minority stress experiences emerged in the narratives in the context of couples' long-term commitment, the availability of civil marriage, and couples' participation in activist efforts on behalf of marriage equality for themselves and others. PMID:27191207

  10. [Infant mortality among the black population of Brazil, 1960-1980].

    Science.gov (United States)

    Tamburo, E M

    1987-08-01

    This is a comparative analysis of infant mortality trends for the period 1960-1980 among blacks, whites, and mixed race population groups in Brazil, based on data from official sources. The impact of marital and educational status is considered. The study is confined to the states of Bahia, Minas Gerais, Rio Grande do Sul, and Sao Paulo. An appendix on the methodological issues involved is included.

  11. The inter-relationship among economic activities, environmental degradation, material consumption and population health in low-income countries: a longitudinal ecological study

    Science.gov (United States)

    Chuang, Ying-Chih; Huang, Ya-Li; Hu, Ching-Yao; Chen, Ssm-Ching; Tseng, Kuo-Chien

    2015-01-01

    Objectives The theory of ecological unequal exchange explains how trade and various forms of economic activity create the problem of environmental degradation, and lead to the deterioration of population health. Based on this theory, our study examined the inter-relationship among economic characteristics, ecological footprints, CO2 emissions, infant mortality rates and under-5 mortality rates in low-income countries. Design A longitudinal ecological study design. Setting Sixty-six low-income countries from 1980 to 2010 were included in the analyses. Data for each country represented an average of 23 years (N=1497). Data sources Data were from the World Development Indicators, UN Commodity Trade Statistics Database, Global Footprint Network and Polity IV Project. Analyses Linear mixed models with a spatial power covariance structure and a correlation that decreased over time were constructed to accommodate the repeated measures. Statistical analyses were conducted separately by sub-Saharan Africa, Latin America and other regions. Results After controlling for country-level sociodemographic characteristics, debt and manufacturing, economic activities were positively associated with infant mortality rates and under-5 mortality rates in sub-Saharan Africa. By contrast, export intensity and foreign investment were beneficial for reducing infant and under-5 mortality rates in Latin America and other regions. Although the ecological footprints and CO2 emissions did not mediate the relationship between economic characteristics and health outcomes, export intensity increased CO2 emissions, but reduced the ecological footprints in sub-Saharan Africa. By contrast, in Asia, the Middle East and North Africa, although export intensity was positively associated with the ecological footprints and also CO2 emissions, the percentage of exports to high-income countries was negatively associated with the ecological footprints. Conclusions This study suggested that environmental

  12. Cross-sectional study of sleep quantity and quality and amnestic and non-amnestic cognitive function in an ageing population: the English Longitudinal Study of Ageing (ELSA.

    Directory of Open Access Journals (Sweden)

    Michelle A Miller

    Full Text Available BACKGROUND: The aim was to investigate the association between sleep disturbances and cognitive function in younger and older individuals from an ageing population. METHODS: 3,968 male and 4,821 female white participants, aged 50 years and over, from the English Longitudinal Study of Ageing (ELSA were studied. Information on sleep quality and quantity as well as both amnestic (memory, ACF and non-amnestic (non-memory, nACF function was available at Wave 4 (2008. Analysis of covariance was used to evaluate the relationship between sleep and cognitive function. RESULTS: After adjustment for multiple confounders in the younger group (50-64 years duration of sleep explained 15.2% of the variance in ACF (p = 0.003 and 20.6% of nACF (p = 0.010. In the older group (65+ years the estimates were 21.3% (p<0.001 and 25.6% (p<0.001, respectively. For sleep quality, there was a statistically significant association between sleep quality and both ACF (p<0.001 and nACF (p<0.001 in the older age group, but not in the younger age group (p = 0.586 and p = 0.373, respectively; interaction between age and sleep quality in the study sample including both age groups: p<0.001 for ACF and p = 0.018 for nACF. Sleep quality explained between 15.1% and 25.5% of the variance in cognition. The interaction with age was independent of duration of sleep. At any level of sleep duration there was a steeper association between sleep quality and ACF in the older than the younger group. CONCLUSIONS: The associations between sleep disturbances and cognitive function vary between younger and older adults. Prospective studies will determine the temporal relationships between sleep disturbances and changes in cognition in different age groups.

  13. Childhood trajectories of inattention, hyperactivity and oppositional behaviors and prediction of substance abuse/dependence: a 15-year longitudinal population-based study.

    Science.gov (United States)

    Pingault, J-B; Côté, S M; Galéra, C; Genolini, C; Falissard, B; Vitaro, F; Tremblay, R E

    2013-07-01

    Numerous prospective studies have shown that children diagnosed with attention deficit/hyperactivity disorder (ADHD) are at higher risk of long-term substance abuse/dependence. However, there are three important limits to these studies: (a) most did not differentiate the role of hyperactivity and inattention; (b) most did not control for associated behavioral problems; and (c) most did not consider females. Our aim was to clarify the unique and interactive contributions of childhood inattention and hyperactivity symptoms to early adulthood substance abuse/dependence. Behavioral problems of 1803 participants (814 males) in a population-based longitudinal study were assessed yearly between 6 and 12 years by mothers and teachers. The prevalence of substance abuse/dependence at age 21 years was 30.7% for nicotine, 13.4% for alcohol, 9.1% for cannabis and 2.0% for cocaine. The significant predictors of nicotine dependence were inattention (odds ratio (OR): 2.25; 95% confidence interval (CI): 1.63-3.11) and opposition (OR: 1.65; 95%: 1.20-2.28). Only opposition contributed to the prediction of cannabis dependence (OR: 2.33; 95% CI: 1.40-3.87) and cocaine dependence (OR: 2.97; 95% CI: 1.06-8.57). The best behavioral predictor of alcohol abuse/dependence (opposition) was only marginally significant (OR: 1.38; 95% CI: 0.98-1.95). Frequent oppositional behaviors during elementary school were clearly the most pervasive predictors of substance abuse/dependence in early adulthood. The association of childhood ADHD with substance abuse/dependence is largely attributable to its association with opposition problems during childhood. However, inattention remained an important predictor of nicotine dependence, in line with genetic and molecular commonalities between the two phenotypes suggested in the literature. PMID:22733124

  14. Populism

    OpenAIRE

    Abts, Koenraad; van Kessel, Stijn

    2015-01-01

    Populism is a concept applied to a wide range of political movements and actors across the globe. There is, at the same time, considerable confusion about the attributes and manifestation of populism, as well as its impact on democracy. This contribution identifies the defining elements of the populist ideology and discusses the varieties in which populism manifests itself, for instance as a component of certain party families. We finally discuss various normative interpretations of populism,...

  15. Health-related factors correlate with behavior trends in physical activity level in old age: longitudinal results from a population in São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    Ribeiro Manoel CSA

    2010-11-01

    Full Text Available Abstract Background Physical inactivity in leisure time is common among elderly in Brazil and this finding is particularly alarming considering that this population is greatly affected by chronic diseases. The identification of health factors that influence physical activity level (PAL will help in the development of strategies for increasing PAL older adults. The current research aimed to identify variables that independently affect behavior trends in PAL over the course of two years among elderly. Methods A survey entitled the Epidoso Project ("Epidemiology of aging" studied 1,667 community-based older individuals in São Paulo city, Brazil over the course of two years. Physical activity level was determined through questions about frequency and duration of physical activities. Body Mass Index was calculated; functional capacity was assessed through the ADL (activities of daily living scale; cognition was assessed by Mini-Mental State Examination; and mental health was assessed through the Dysthymia Screening. Experiences of falls and fractures were also assessed. Subjects were divided into three groups according to their self-report of Physical Activity Level: a - Regularly Active; b - Insufficiently Active and c - Physically Inactive. Behavior trends in PAL were also measured after two years. Multivariate regression model methodology was used to test associations longitudinally. Results Results from the final model demonstrated that the risk of a not favorable behavior trend in PAL, which included the group who remained physically inactive and the group that displayed decreased PAL, in this cohort of older adults was significantly increased if the individual was female (OR = 2.50; 95% CI = 1.60-3.89; P , older (80 y vs. 65 y, OR = 6.29, 95% CI = 2.69-14.67; P , dependent on help from others for activities in the ADL scale (moderate-severe = 4-7+ vs. 0 ADLs (OR = 2.25, 95% CI = 1.20-4.21; P or had experienced a history of falls with

  16. Repeatability and Minimal Detectable Change in Longitudinal Median Nerve Excursion Measures During Upper Limb Neurodynamic Techniques in a Mixed Population: A Pilot Study Using Musculoskeletal Ultrasound Imaging.

    Science.gov (United States)

    Paquette, Philippe; Lamontagne, Martin; Higgins, Johanne; Gagnon, Dany H

    2015-07-01

    This study determined test-retest reliability and minimum detectable change in longitudinal median nerve excursion during upper limb neurodynamic tests (ULNTs). Seven participants with unilateral or bilateral carpal tunnel syndrome and 11 healthy participants were randomly tested with two ULNTs (i.e., tensioner and slider). Each ULNT was performed three times each at 45° and 90° of shoulder abduction on two separate visits. Video sequences of median nerve excursion, recorded by a physical therapist using ultrasound imaging, were quantified using computer software. The generalizability theory, encompassing a G-Study and a D-study, measured the dependability coefficient (Φ) along with standard error of measurement (SEM) accuracy and allowed various testing protocols to be proposed. The highest reliability (Φ = 0.84) and lowest minimal measurement error (SEM = 0.58 mm) of the longitudinal median nerve excursion were reached during the ULNT-slider performed with 45° of shoulder abduction and when measures obtained from three different image sequences recorded during a single visit were averaged. It is recommended that longitudinal median nerve excursion measures computed from three separate image sequences recorded during a single visit be averaged in clinical practice. Ideally, adding a second visit (six image sequences) is also suggested in research protocols. PMID:25868536

  17. Genetic and phenotypic changes in an Atlantic salmon population supplemented with non-local individuals: a longitudinal study over 21 years.

    Science.gov (United States)

    Le Cam, Sabrina; Perrier, Charles; Besnard, Anne-Laure; Bernatchez, Louis; Evanno, Guillaume

    2015-03-01

    While introductions and supplementations using non-native and potentially domesticated individuals may have dramatic evolutionary effects on wild populations, few studies documented the evolution of genetic diversity and life-history traits in supplemented populations. Here, we investigated year-to-year changes from 1989 to 2009 in genetic admixture at 15 microsatellite loci and in phenotypic traits in an Atlantic salmon (Salmo salar) population stocked during the first decade of this period with two genetically and phenotypically distinct source populations. We detected a pattern of temporally increasing introgressive hybridization between the stocked population and both source populations. The proportion of fish returning to the river after a single winter at sea (versus several ones) was higher in fish assigned to the main source population than in local individuals. Moreover, during the first decade of the study, both single-sea-winter and multi-sea-winter (MSW) fish assigned to the main source population were smaller than local fish. During the second decade of the study, MSW fish defined as hybrids were lighter and smaller than fish from parental populations, suggesting outbreeding depression. Overall, this study suggests that supplementation with non-local individuals may alter not only the genetic diversity of wild populations but also life-history traits of adaptive significance. PMID:25608883

  18. Fractal dimension and lacunarity analysis of mammographic patterns in assessing breast cancer risk related to HRT treated population: a longitudinal and cross-sectional study

    Science.gov (United States)

    Karemore, Gopal; Nielsen, Mads

    2009-02-01

    Structural texture measures are used to address the aspect of breast cancer risk assessment in screening mammograms. The current study investigates whether texture properties characterized by local Fractal Dimension (FD) and Lacunarity contribute to asses breast cancer risk. FD represents the complexity while the Lacunarity characterize the gappiness of a fractal. Our cross-sectional case-control study includes mammograms of 50 patients diagnosed with breast cancer in the subsequent 2-4 years and 50 matched controls. The longitudinal double blind placebo controlled HRT study includes 39 placebo and 36 HRT treated volunteers for two years. ROIs with same dimension (250*150 pixels) were created behind the nipple region on these radiographs. Box counting method was used to calculate the fractal dimension (FD) and the Lacunarity. Paired t-test and Pearson correlation coefficient were calculated. It was found that there were no differences between cancer and control group for FD (P=0.8) and Lacunarity (P=0.8) in crosssectional study whereas earlier published heterogeneity examination of radiographs (BC-HER) breast cancer risk score separated groups (p=0.002). In the longitudinal study, FD decreased significantly (Pbreast cancer risk, nor show good sensitivity to HRT.

  19. Effect of Health Comparisons on Functional Health and Depressive Symptoms - Results of a Population-Based Longitudinal Study of Older Adults in Germany.

    Directory of Open Access Journals (Sweden)

    André Hajek

    Full Text Available To investigate the effect of health comparisons on functional health and depressive symptoms in a longitudinal approach. Gender differences were examined.The German Ageing Survey (DEAS is a nationwide, representative longitudinal study of community dwelling individuals living in Germany aged 40 and older. The surveys in 2008 and 2011 were used, with n = 3,983 respondents taking part in both waves. Health comparisons were quantified by the question "How would you rate your health compared with other people your age" (Much better; somewhat better; the same; somewhat worse, much worse. Functional health was assessed by the subscale "physical functioning" of the 36-Item Short Form Health Survey (SF-36 and depressive symptoms were measured by the Center for Epidemiologic Studies Depression Scale (CES-D.Adjusting for sociodemographic factors, self-assessed health, social network, self-efficacy and optimism, and morbidity, fixed effects regressions revealed that functional health decreased significantly and considerably with negative health comparisons in the total sample (transitions from 'the same' to 'much worse': β = -11.8, predominantly in men. The effects of negative health comparisons (transitions from 'the same' to 'much worse': β = 4.8 on depressive symptoms were comparable (in terms of significance to the effects on functional health, with stronger effects in women. Positive comparisons did not affect functional health and depressive symptoms.Our findings underline the relevance of negative health comparisons on functional health (men and depressive symptoms (women. Comparison effects are asymmetric and mostly upwards.

  20. Effects of aging on the function of the urinary system: longitudinal changes with age in selected urine parameters in a hospitalized population of older adults

    Directory of Open Access Journals (Sweden)

    Chmielewski Piotr

    2016-09-01

    Full Text Available Although normal aging does not have a pernicious effect on the homeostasis of fluids, renal reserve in elderly people can be depleted. The purpose of the present study was to assess the relationship between longitudinal changes with age in basic urine parameters (specific gravity and pH in older men and women, depending on their body height and relative body weight. Longitudinal data on these two quantitative traits of the urine were available for 142 physically healthy individuals, including 68 men and 74 women. All subjects were 45 years of age at the beginning and 70 at the end of the period under investigation. All measurements were taken in accordance with internationally accepted requirements. Specific gravity was assessed using a hydrometer, and pH was measured using a pH meter. ANOVA, t-test, and regression analysis were performed. No significant sex differences in specific gravity or urine pH were observed. In both sexes, urine specific gravity decreased with age according to exponential model of regression. In men, there was a gradual increase in the pH of the urine until age 65, and the best fitting regression model was polynomial. In women, on the other hand, there was an exiguous decrease in urine pH throughout the period under study, and the best fitting regression model proved to be exponential. As the process of renal aging commences relatively early in ontogeny and manifests itself in many structural and functional changes, urinalysis and other more sophisticated methods of diagnosis of renal diseases are essential for proper assessment of health status of adults and older individuals. The rate of age-related changes in the analyzed traits of the urine was commensurate in both sexes, thereby revealing no evidence of significant sex differences in terms of renal aging in the period between 45 and 70 years of age.

  1. Risk factors associated with trajectories of mothers' depressive symptoms across the early parenting period: an Australian population-based longitudinal study.

    Science.gov (United States)

    Giallo, Rebecca; Cooklin, Amanda; Nicholson, Jan M

    2014-04-01

    Approximately 14 % of women experience depressive symptoms in the first postnatal year. Few studies have examined the persistence of symptoms beyond this time. This study aims to (a) assess the course of women's depressive symptoms from the first postnatal year to when their children were aged 6-7 years, (b) identify distinct groups of women defined by their symptom trajectories over time, and (c) identify antenatal and early postnatal risk factors associated with persistent symptoms. Data from 4,879 women participating in the Longitudinal Study of Australian Children were analysed using latent growth modelling and logistic regression to identify risk factors associated with class membership. For the overall sample, depressive symptoms were highest during the first postnatal year and then gradually decreased over 6-7 years. Two distinct classes were identified with the majority of women (84 %) reporting minimal symptoms over time, and 16 % experiencing persistently high symptoms. Risk factors were younger maternal age, being from a non-English speaking background, not completing high school, having a past history of depression, antidepressant use during pregnancy, child development problems, lower parenting self-efficacy, poor relationship quality, and stressful life events. This research identifies risk factors that may predispose mothers to enduring depressive symptoms, offering opportunities for early identification and targeted early intervention.

  2. A population-based longitudinal study of recent stressful life events as risk factors for suicidal behavior in major depressive disorder.

    Science.gov (United States)

    Wang, Yunqiao; Sareen, Jitender; Afifi, Tracie O; Bolton, Shay-Lee; Johnson, Edward A; Bolton, James M

    2015-01-01

    The purpose of this study is to investigate whether the type and number of stressful life events (SLEs) will be associated with suicidal behavior in a 3-year follow-up period in persons with major depressive disorder (MDD). Data came from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC), a nationally representative longitudinal survey of mental health in non-institutionalized adults in the United States. The survey consisted of two waves: Wave 1 (2001--2002) and Wave 2 (2004-2005), n = 34,653. Twelve past-year SLEs were assessed at baseline. These SLEs were categorized into the following groups based on previous research: Loss or victimization; Relationship, friendship, or interpersonal stress; Financial stress; and Legal problems. Only respondents with MDD at Wave 1 were included (n = 6,004). Several SLEs were strongly associated with suicide attempts, among which, "serious problems with neighbor, friend, or relative" (adjusted odds ratio [AOR] = 2.21; 95% confidence interval [95% CI]: 1.41, 3.45) and "major financial crisis, bankruptcy, or unable to pay bills" (AOR = 2.31; 95% CI: 1.45, 3.66) were the most robust predictors of suicide attempts even after adjusting for sociodemographic variables and any anxiety, substance use, or personality disorder. People with MDD who had been exposed to certain SLEs are at elevated risk for future suicide attempts, even after accounting for the demographic factors and psychiatric comorbidity. PMID:25559346

  3. Classification-based data mining for identification of risk patterns associated with hypertension in Middle Eastern population: A 12-year longitudinal study.

    Science.gov (United States)

    Ramezankhani, Azra; Kabir, Ali; Pournik, Omid; Azizi, Fereidoun; Hadaegh, Farzad

    2016-08-01

    Hypertension is a critical public health concern worldwide. Identification of risk factors using traditional multivariable models has been a field of active research. The present study was undertaken to identify risk patterns associated with hypertension incidence using data mining methods in a cohort of Iranian adult population.Data on 6205 participants (44% men) age > 20 years, free from hypertension at baseline with no history of cardiovascular disease, were used to develop a series of prediction models by 3 types of decision tree (DT) algorithms. The performances of all classifiers were evaluated on the testing data set.The Quick Unbiased Efficient Statistical Tree algorithm among men and women and Classification and Regression Tree among the total population had the best performance. The C-statistic and sensitivity for the prediction models were (0.70 and 71%) in men, (0.79 and 71%) in women, and (0.78 and 72%) in total population, respectively. In DT models, systolic blood pressure (SBP), diastolic blood pressure, age, and waist circumference significantly contributed to the risk of incident hypertension in both genders and total population, wrist circumference and 2-h postchallenge plasma glucose among women and fasting plasma glucose among men. In men, the highest hypertension risk was seen in those with SBP > 115 mm Hg and age > 30 years. In women those with SBP > 114 mm Hg and age > 33 years had the highest risk for hypertension. For the total population, higher risk was observed in those with SBP > 114 mm Hg and age > 38 years.Our study emphasizes the utility of DTs for prediction of hypertension and exploring interaction between predictors. DT models used the easily available variables to identify homogeneous subgroups with different risk pattern for the hypertension.

  4. Shaded Relief of Minnesota Elevation - Black & White

    Data.gov (United States)

    Minnesota Department of Natural Resources — This file is a product of a shaded relief process on the 30 meter resolution Digital Elevation Model data (dem30im3). This image was created using a custom AML...

  5. Longitudinal association between early atopic dermatitis and subsequent attention-deficit or autistic disorder: A population-based case-control study.

    Science.gov (United States)

    Lee, Chih-Ying; Chen, Mu-Hong; Jeng, Mei-Jy; Hsu, Ju-Wei; Tsai, Shih-Jen; Bai, Ya-Mei; Hung, Giun-Yi; Yen, Hsiu-Ju; Chen, Tzeng-Ji; Su, Tung-Ping

    2016-09-01

    Atopic dermatitis (AD) is one of the common allergic diseases in children. The presence of allergic diseases was found to have association with the risk of developing attention-deficit hyperactivity disorder (ADHD) or autistic spectrum disorder (ASD) in children, but it is still inconclusive. This study was to investigate the longitudinal relationship between AD developed during toddlerhood and subsequent development of ADHD or ASD in later childhood. Toddlers born between 1998 and 2008 and diagnosed with AD at the age younger than 3 years and older than 1 month were retrieved from Taiwan's National Health Insurance Research Database. Age- and gender-matched toddlers with no lifetime AD were enrolled as the control group. All enrolled toddlers were followed until 2011 to identify the development of ADHD or ASD. Multivariate Cox regression analysis was performed to analyze the hazard ratios (HRs). The risks associated with allergic comorbidities were analyzed. A total of 18,473 toddlers were enrolled into the AD group. The presence of AD significantly increased the risk of developing ADHD (HR = 2.92, 95% confidence interval [CI] = 2.48-3.45) or ASD (HR = 8.90, 95% CI = 4.98-15.92) when aged 3 years or older. Children from the AD group with 3 comorbidities together, namely, allergic rhinitis, allergic conjunctivitis, and asthma, had the greatest risk of developing ADHD and ASD (ADHD: HR = 4.67, 95% CI = 3.81-5.43; ASD: HR = 16.65, 95% CI = 8.63-30.60). In conclusion, toddlers who suffer from AD at the age younger than 3 years are at a higher risk of developing ADHD and ASD during later childhood. Pediatricians taking care of toddlers with AD should have knowledge of this increased risk of developing ADHD and ASD later in life, especially when children have certain comorbidities such as allergic rhinitis, allergic conjunctivitis, and asthma. PMID:27684861

  6. 不同水平肌醇对黑白花奶牛乳成分的影响%The effect of different levels of inoses on milk composition of black-white dairy cows

    Institute of Scientific and Technical Information of China (English)

    孙超; 高景慧; 张文晋

    2001-01-01

    Forty black-white dairy cows were used as experimental animals.T hey were divided into three experimental groups and a contrast group.The experi mental groups were added respectively 0.1,\\{0.2\\},0.3 g/(one*d) inoses to study the effect of different levels of inoses on milk yield,food consumption and mil k composition.The results showed:the increasing degrees of milk yield,food consu mption and milkfat,milkprotein,milksuger,nonfat solidity,total solidity in the s econd experimental group were the biggest,3.76 kg/d,3.36 kg/d,0.90 g/kg,0.91g/ k g,0.73 g/kg/d,1.04 g/ kg,1.00 g/ kg,respectively.It proved that adding 0.2 g/(on e*d) inoses in the diets for dairy cows was best for promoting milk yield,food consumption and milk composition.%以40头黑白花奶牛为实验动物,随机分成3个试验组和1个对照组,各试验组分别添加0.1,0.2,0.3 g/(头*d)肌醇,研究其对奶牛产奶量、采食量以及乳成份的影响。结果表明:试验Ⅱ组中产奶量、采食量、乳脂、乳蛋白、乳糖、无脂固形物和总固形物的增加量最大,分别为3.76 kg/d,3.36 kg/d,0.90 g/kg,0.91 g/kg,\\{0.73 g/kg\\},1.04 g/kg和1.00 g/ kg。证明在奶牛日粮中添加0.2 g/(头*d)肌醇对提高产奶量,采食量以及乳成份最好。

  7. Disentangling contextual effects on cause-specific mortality in a longitudinal 23-year follow-up study: impact of population density or socioeconomic environment?

    OpenAIRE

    Chaix, Basile; Rosvall, Maria; Lynch, John; Merlo, Juan

    2006-01-01

    BACKGROUND: Various studies have investigated urban/rural differences in cause-specific mortality. A separate body of literature has analysed effects of socioeconomic environment on mortality. Almost no studies have attempted to disentangle effects of population density and socioeconomic environment on mortality, beyond the effects of individual characteristics. METHODS: Considering all individuals living in the region of Scania, Sweden, from 1970-93, we performed 10 year mortality follow-ups...

  8. Relationship between obesity and antipsychotic drug use in the adult population: A longitudinal, retrospective claim database study in Primary Care settings

    Directory of Open Access Journals (Sweden)

    Antoni Sicras-Mainar

    2008-03-01

    Full Text Available Antoni Sicras-Mainar1, Ruth Navarro-Artieda2, Javier Rejas-Gutiérrez3, Milagrosa Blanca-Tamayo41Planning Management, Badalona Serveis Assistencials S.A., Badalona, Barcelona, Spain; 2Medical Documentation Service, Hospital Germans Trías i Pujol, Badalona, Barcelona, Spain; 3Health Outcomes Research Derpartment, Medical Unit, Pfizer Spain, Alcobendas, Madrid, Spain; 4Department of Psychiatry, Badalona Serveis Assistencials S.A., Badalona, Barcelona, SpainObjective: To describe the association between obesity and the use of antipsychotic drugs (APDs in adult outpatients followed-up on in five Primary Care settings.Methods: A longitudinal, retrospective design study carried out between July 2004 and June 2005, in patients who were included in a claim database and for whom an APD treatment had been registered. A body mass index (BMI <30 kg/m2 was defined as obesity. The main measurements were: use of APDs, demographics, medical background and co-morbidities, and clinical parameters. Logistic regression analysis and ANCOVA with Bonferroni adjustment were applied to correct the model.Results: A total of 42,437 subjects (mean age: 50.8 (18.4 years; women: 54.5%; obesity: 27.3% [95% confidence intervals (CI, 26.9%–27.7%] were analyzed. A total of 1.3% of the patients were receiving APDs, without statistical differences in distribution by type of drug (typical: 48.8%; atypical: 51.2%. Obesity was associated with the use of APDs [OR = 1.5 (CI: 1.3–1.8], hypertension [OR = 2.4 (CI: 2.2–2.5], diabetes [OR = 1.4 (CI: 1.3–1.5] and dyslipidemia [OR = 1.3 (CI: 1.2–1.4], p < 0.0001 in all cases. BMI was significantly higher in subjects on APDs; 28.8 vs. 27.3 kg/m2, p = 0.002, and remained higher after adjusting by age and sex (mean difference 0.4 (CI: 0.1–0.7, p < 0.01. After adjusting by age, sex and the Charlson index, obese subjects generated higher average annual total costs than nonobese subjects; 811 (CI: 787–835 vs. 694 (CI: 679–709

  9. Anthropometric differences between HIV-infected individuals prior to antiretroviral treatment and the general population from 1998-2007: the AIDS Clinical Trials Group Longitudinal Linked Randomized Trials (ALLRT cohort and NHANES.

    Directory of Open Access Journals (Sweden)

    Benjamin E Atkinson

    Full Text Available OBJECTIVE: To assess differences in body circumferences and body mass index (BMI, kg/m(2 between antiretroviral treatment (ART naïve HIV-infected and HIV-uninfected persons. METHODS: Waist, arm, and thigh circumferences and BMI were measured within the ALLRT and NHANES cohorts between 1998 and 2007. ALLRT is a prospective, longitudinal study of U.S. participants enrolled in randomized HIV treatment studies conducted by the AIDS Clinical Trials Group (ACTG. NHANES is a representative group of the US population. The cohorts were analyzed in two time periods, to account for trends towards increased adiposity. Anthropometrics were displayed in percentiles by age and sex. Multiple linear regression models examined differences between cohorts. RESULTS: ALLRT had more males (82% versus 48%, p<0.0001, more black participants (32% versus 23%, p<0.0001, and less Hispanics (21% versus 30%, p<0.0001 than NHANES. Mean BMI was smaller in ALLRT males and females compared to NHANES by 1.6-2.4 kg/m(2 (p<0.0001. Mean waist and arm circumferences in both sexes and time periods were significantly smaller in ALLRT than in NHANES (p<0.0001. Mean thigh circumference in ALLRT was also smaller than NHANES among males (p<0.0001 in both time periods and females (p = 0.01 in the early time period. CONCLUSIONS: Differences in anthropometrics existed prior to ART initiation, in this large national cohort of HIV-infected individuals, compared to a representative HIV-uninfected cohort, indicating that HIV and its complications have important effects on body shape. Further longitudinal examination of anthropometrics in this HIV-infected cohort may provide additional insight into disease risk. TRIAL REGISTRATION: NCT00001137 at www.clinicaltrials.gov.

  10. Dynamics from Multivariable Longitudinal Data

    Directory of Open Access Journals (Sweden)

    Maria Vivien Visaya

    2014-01-01

    Full Text Available We introduce a method of analysing longitudinal data in n≥1 variables and a population of K≥1 observations. Longitudinal data of each observation is exactly coded to an orbit in a two-dimensional state space Sn. At each time, information of each observation is coded to a point (x,y∈Sn, where x is the physical condition of the observation and y is an ordering of variables. Orbit of each observation in Sn is described by a map that dynamically rearranges order of variables at each time step, eventually placing the most stable, least frequently changing variable to the left and the most frequently changing variable to the right. By this operation, we are able to extract dynamics from data and visualise the orbit of each observation. In addition, clustering of data in the stable variables is revealed. All possible paths that any observation can take in Sn are given by a subshift of finite type (SFT. We discuss mathematical properties of the transition matrix associated to this SFT. Dynamics of the population is a nonautonomous multivalued map equivalent to a nonstationary SFT. We illustrate the method using a longitudinal data of a population of households from Agincourt, South Africa.

  11. Applied longitudinal analysis

    CERN Document Server

    Fitzmaurice, Garrett M; Ware, James H

    2012-01-01

    Praise for the First Edition "". . . [this book] should be on the shelf of everyone interested in . . . longitudinal data analysis.""-Journal of the American Statistical Association   Features newly developed topics and applications of the analysis of longitudinal data Applied Longitudinal Analysis, Second Edition presents modern methods for analyzing data from longitudinal studies and now features the latest state-of-the-art techniques. The book emphasizes practical, rather than theoretical, aspects of methods for the analysis of diverse types of lo

  12. A longitudinal evaluation of the Center for Epidemiologic Studies-Depression scale (CES-D in a Rheumatoid Arthritis Population using Rasch Analysis

    Directory of Open Access Journals (Sweden)

    Tennant Alan

    2007-07-01

    Full Text Available Abstract Background The aim of this study was to test the internal validity of the total Center for Epidemiologic Studies-Depression (CES-D scale using Rasch analysis in a rheumatoid arthritis (RA population. Methods CES-D was administered to 157 patients with RA over three time points within a 12 month period. Rasch analysis was applied using RUMM2020 software to assess the overall fit of the model, the response scale used, individual item fit, differential item functioning (DIF and person separation. Results Pooled data across three time points was shown to fit the Rasch model with removal of seven items from the original 20-item CES-D scale. It was necessary to rescore the response format from four to three categories in order to improve the scale's fit. Two items demonstrated some DIF for age and gender but were retained within the 13-item CES-D scale. A new cut point for depression score of 9 was found to correspond to the original cut point score of 16 in the full CES-D scale. Conclusion This Rasch analysis of the CES-D in a longstanding RA cohort resulted in the construction of a modified 13-item scale with good internal validity. Further validation of the modified scale is recommended particularly in relation to the new cut point for depression.

  13. Maternal Consumption of Seafood in Pregnancy and Child Neuropsychological Development: A Longitudinal Study Based on a Population With High Consumption Levels.

    Science.gov (United States)

    Julvez, Jordi; Méndez, Michelle; Fernandez-Barres, Silvia; Romaguera, Dora; Vioque, Jesus; Llop, Sabrina; Ibarluzea, Jesus; Guxens, Monica; Avella-Garcia, Claudia; Tardón, Adonina; Riaño, Isolina; Andiarena, Ainara; Robinson, Oliver; Arija, Victoria; Esnaola, Mikel; Ballester, Ferran; Sunyer, Jordi

    2016-02-01

    Seafood consumption during pregnancy is thought to be beneficial for child neuropsychological development, but to our knowledge no large cohort studies with high fatty fish consumption have analyzed the association by seafood subtype. We evaluated 1,892 and 1,589 mother-child pairs at the ages of 14 months and 5 years, respectively, in a population-based Spanish birth cohort established during 2004-2008. Bayley and McCarthy scales and the Childhood Asperger Syndrome Test were used to assess neuropsychological development. Results from multivariate linear regression models were adjusted for sociodemographic characteristics and further adjusted for umbilical cord blood mercury or long-chain polyunsaturated fatty acid concentrations. Overall, consumption of seafood above the recommended limit of 340 g/week was associated with 10-g/week increments in neuropsychological scores. By subtype, in addition to lean fish, consumption of large fatty fish showed a positive association; offspring of persons within the highest quantile (>238 g/week) had an adjusted increase of 2.29 points in McCarthy general cognitive score (95% confidence interval: 0.42, 4.16). Similar findings were observed for the Childhood Asperger Syndrome Test. Beta coefficients diminished 15%-30% after adjustment for mercury or long-chain polyunsaturated fatty acid concentrations. Consumption of large fatty fish during pregnancy presents moderate child neuropsychological benefits, including improvements in cognitive functioning and some protection from autism-spectrum traits. PMID:26740026

  14. Metabolic risk in contemporary children is unrelated to socio-economic status: longitudinal study of a UK urban population (EarlyBird 42).

    Science.gov (United States)

    Voss, Linda D; Hosking, Joanne; Metcalf, Brad S; Jeffery, Alison N; Frémeaux, Alissa E; Wilkin, Terence J

    2014-05-01

    Lifestyle interventions to improve health in young children tend to target areas of relative deprivation, but the evidence for so doing is largely historical. Accordingly, we have re-examined the link between deprivation, obesity and metabolic risk in contemporary UK children. Using a postcode-based index of multiple deprivation (IMD), we assessed 269 children from the community-based EarlyBird Study, attending 53 schools representing a wide socio-economic range. Annual measures of fatness from 5 to 8 yr included body mass index (BMI), waist circumference (WC), and sum of five skinfolds (SSF). A metabolic risk score, based on blood pressure, lipids and insulin resistance, was derived from annual fasting blood samples. There were no significant associations between deprivation and any measure of adiposity in girls (all p > 0.37). In boys, there was a weak but consistently inverse relationship between deprivation and WC (r = -0.19, p = 0.03) and BMI (r = -0.14, p = 0.09) at 8 yr. Changes in adiposity over 3 yr were unrelated to deprivation in boys. In girls there was a slight but significant increase in SSF only (1 mm/yr per 20 IMD units, p = 0.001). Importantly, in both genders, metabolic risk score was unrelated to deprivation throughout (r values -0.05 to -0.13, all p > 0.12), as was change in metabolic risk (all p > 0.30). Our data do not support the assumption that obesity, metabolic disturbance and thus risk of type 2 diabetes are more prevalent among poorer children. In today's increasingly obesogenic environment, youngsters from all backgrounds appear to be vulnerable, with population-wide implications for public health spending, and the prevention of diabetes in contemporary youth.

  15. Increased risk of ischemic heart disease in young patients with newly diagnosed ankylosing spondylitis--a population-based longitudinal follow-up study.

    Directory of Open Access Journals (Sweden)

    Ya-Ping Huang

    Full Text Available BACKGROUND: Prospective data is sparse on the association between ischemic heart disease (IHD and ankylosing spondylitis (AS in the young. The purpose of this population-based, age- and sex-matched follow-up study was to investigate the risk of IHD in young patients with newly diagnosed AS. METHODS: A total of 4794 persons aged 18 to 45 years with at least two ambulatory visits in 2001 with the principal diagnosis of AS were enrolled in the AS group. The non-AS group consisted of 23970 age- and sex-matched, randomly sampled subjects without AS. The three-year IHD-free survival rate and cumulative incidence of IHD were calculated using the Kaplan-Meier method. The Cox proportional hazards regression model was used to estimate the hazard ratio of IHD after controlling for demographic and cardiovascular co-morbidities. RESULTS: During follow-up, 70 patients in the AS group and 253 subjects in the non-AS group developed IHD. The cumulative incidence rate of IHD over time was higher in the AS group than the non-AS group. The crude hazard ratio of IHD for the AS group was 1.47 (95% CI, 1.13 to 1.92; p = 0.0043 and the adjusted hazard ratio after controlling for demographic characteristics and comorbid medical disorders was 1.47 (95% CI, 1.13 to 1.92; p = 0.0045. CONCLUSIONS: This study showed an increased risk of developing IHD in young patients with newly diagnosed AS.

  16. C-reactive protein, high-molecular-weight adiponectin and development of metabolic syndrome in the Japanese general population: a longitudinal cohort study.

    Directory of Open Access Journals (Sweden)

    Yoshifumi Saisho

    Full Text Available AIMS: To clarify predictive values of C-reactive protein (CRP and high-molecular-weight (HMW adiponectin for development of metabolic syndrome. RESEARCH DESIGN AND METHODS: We conducted a prospective cohort study of Japanese workers who had participated in an annual health checkup in 2007 and 2011. A total of 750 subjects (558 men and 192 women, age 46±8 years who had not met the criteria of metabolic syndrome and whose CRP and HMW-adiponectin levels had been measured in 2007 were enrolled in this study. Associations between CRP, HMW-adiponectin and development of metabolic syndrome after 4 years were assessed by logistic regression analysis and their predictive values were compared by receiver operating characteristic analysis. RESULTS: Among 750 subjects, 61 (8.1% developed metabolic syndrome defined by modified National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III criteria and 53 (7.1% developed metabolic syndrome defined by Japan Society for the Study of Obesity (JASSO in 2011. Although CRP and HMW-adiponectin were both significantly correlated with development of metabolic syndrome, multivariate logistic regression analysis revealed that HMW-adiponectin but not CRP was associated with metabolic syndrome independently of BMI or waist circumference. Adding these biomarkers to BMI or waist circumference did not improve the predictive value for metabolic syndrome. CONCLUSION: Our findings indicate that the traditional markers of adiposity such as BMI or waist circumference remain superior markers for predicting metabolic syndrome compared to CRP, HMW-adiponectin, or the combination of both among the Japanese population.

  17. A population-based longitudinal study of suicide risk in male schizophrenia patients: Proximity to hospital discharge and the moderating effect of premorbid IQ.

    Science.gov (United States)

    Weiser, Mark; Kapara, Ori; Werbeloff, Nomi; Goldberg, Shira; Fenchel, Daphna; Reichenberg, Abraham; Yoffe, Rinat; Ginat, Keren; Fruchter, Eyal; Davidson, Michael

    2015-12-01

    Suicide is a major cause of death in schizophrenia. Identifying factors which increase the risk of suicide among schizophrenia patients might help focus prevention efforts. This study examined risk of suicide in male schizophrenia patients using population-based data, examining the timing of suicide in relation to the last hospital discharge, and the effect of premorbid IQ on risk of suicide. Data on 930,000 male adolescents from the Israeli military draft board were linked with data from the Israeli Psychiatric Hospitalization Case Registry and vital statistics from the Israeli Ministry of Health. The relationship between premorbid IQ and risk for suicide was examined among 2881 males hospitalized with schizophrenia and compared to a control group of 566,726 males from the same cohort, who were not hospitalized for a psychiatric disorder, using survival analysis methods. Over a mean follow-up period of 9.9 years (SD=5.8, range: 0-22 years), 77/3806 males with schizophrenia died by suicide (a suicide rate of 204.4 per 100,000 person-years). Approximately 48% of the suicides occurred within a year of discharge from the last hospital admission for schizophrenia. Risk of suicide was higher in male schizophrenia patients with high premorbid IQ (HR=4.45, 95% CI=1.37-14.43) compared to those with normal premorbid IQ. These data indicate that male schizophrenia patients with high premorbid IQ are at particularly high risk of suicide, and the time of peak risk is during the first year after the last hospitalization discharge.

  18. A population-based longitudinal study of suicide risk in male schizophrenia patients: Proximity to hospital discharge and the moderating effect of premorbid IQ.

    Science.gov (United States)

    Weiser, Mark; Kapara, Ori; Werbeloff, Nomi; Goldberg, Shira; Fenchel, Daphna; Reichenberg, Abraham; Yoffe, Rinat; Ginat, Keren; Fruchter, Eyal; Davidson, Michael

    2015-12-01

    Suicide is a major cause of death in schizophrenia. Identifying factors which increase the risk of suicide among schizophrenia patients might help focus prevention efforts. This study examined risk of suicide in male schizophrenia patients using population-based data, examining the timing of suicide in relation to the last hospital discharge, and the effect of premorbid IQ on risk of suicide. Data on 930,000 male adolescents from the Israeli military draft board were linked with data from the Israeli Psychiatric Hospitalization Case Registry and vital statistics from the Israeli Ministry of Health. The relationship between premorbid IQ and risk for suicide was examined among 2881 males hospitalized with schizophrenia and compared to a control group of 566,726 males from the same cohort, who were not hospitalized for a psychiatric disorder, using survival analysis methods. Over a mean follow-up period of 9.9 years (SD=5.8, range: 0-22 years), 77/3806 males with schizophrenia died by suicide (a suicide rate of 204.4 per 100,000 person-years). Approximately 48% of the suicides occurred within a year of discharge from the last hospital admission for schizophrenia. Risk of suicide was higher in male schizophrenia patients with high premorbid IQ (HR=4.45, 95% CI=1.37-14.43) compared to those with normal premorbid IQ. These data indicate that male schizophrenia patients with high premorbid IQ are at particularly high risk of suicide, and the time of peak risk is during the first year after the last hospitalization discharge. PMID:26490295

  19. A synthetic Longitudinal Study dataset for England and Wales.

    Science.gov (United States)

    Dennett, Adam; Norman, Paul; Shelton, Nicola; Stuchbury, Rachel

    2016-12-01

    This article describes the new synthetic England and Wales Longitudinal Study 'spine' dataset designed for teaching and experimentation purposes. In the United Kingdom, there exist three Census-based longitudinal micro-datasets, known collectively as the Longitudinal Studies. The England and Wales Longitudinal Study (LS) is a 1% sample of the population of England and Wales (around 500,000 individuals), linking individual person records from the 1971 to 2011 Censuses. The synthetic data presented contains a similar number of individuals to the original data and accurate longitudinal transitions between 2001 and 2011 for key demographic variables, but unlike the original data, is open access. PMID:27656667

  20. A synthetic Longitudinal Study dataset for England and Wales.

    Science.gov (United States)

    Dennett, Adam; Norman, Paul; Shelton, Nicola; Stuchbury, Rachel

    2016-12-01

    This article describes the new synthetic England and Wales Longitudinal Study 'spine' dataset designed for teaching and experimentation purposes. In the United Kingdom, there exist three Census-based longitudinal micro-datasets, known collectively as the Longitudinal Studies. The England and Wales Longitudinal Study (LS) is a 1% sample of the population of England and Wales (around 500,000 individuals), linking individual person records from the 1971 to 2011 Censuses. The synthetic data presented contains a similar number of individuals to the original data and accurate longitudinal transitions between 2001 and 2011 for key demographic variables, but unlike the original data, is open access.

  1. A Functional Vesicular Monoamine Transporter 1 (VMAT1) Gene Variant Is Associated with Affect and the Prevalence of Anxiety, Affective, and Alcohol Use Disorders in a Longitudinal Population-Representative Birth Cohort Study

    Science.gov (United States)

    Vaht, Mariliis; Kiive, Evelyn; Veidebaum, Toomas

    2016-01-01

    Background: Inter-individual differences in the monoaminergic systems have been shown to moderate the risk for a lifetime history of anxiety, affective, and alcohol use disorders. A common single nucleotide polymorphism in the vesicular monoamine transporter 1 gene (VMAT1 rs1390938 G/A; Thr136Ile) has been reported as functional in vitro and associated with bipolar disorder and anxiety. We aimed at assessing the association between the VMAT1 genotype, affect, and affect-related psychiatric disorders in a longitudinal population-representative study. Methods: We used the database of the Estonian Children Personality Behaviour and Health Study (beginning in 1998). Cohorts of initially 9- (recalled at ages 15 and 18 years, n=579) and 15- (recalled at ages 18 and 25 years; n=654) year-old children provided self-reports on impulsivity, anxiety, depressiveness, neuroticism, and alcohol use. In addition, psychiatric assessment based on DSM-IV was carried out in the older cohort at age 25 years. Results: Subjects homozygous for the less prevalent A (136Ile) allele reported lower maladaptive impulsivity, state and trait anxiety, depressiveness, and neuroticism and were less likely to have been diagnosed with an affective, anxiety, and/or alcohol use disorder by young adulthood. While in the younger cohort alcohol use started at younger age, this birth cohort effect was dependent on genotype: only G allele carriers and in particular the GG homozygotes started alcohol use earlier. Conclusions: VMAT1 rs1390938/Thr136Ile is associated with mood, personality, and alcohol use in the general population. Subjects homozygous for the “hyperfunction” allele (AA; Ile/Ile) appear to be more resilient to these disorders. PMID:26861143

  2. Intake of Vitamin and Mineral Supplements and Longitudinal Association with HbA1c Levels in the General Non-Diabetic Population--Results from the MONICA/KORA S3/F3 Study.

    Directory of Open Access Journals (Sweden)

    Sigrid Schwab

    Full Text Available Lower levels of hemoglobin A1c (HbA1c are associated with a decreased risk of cardiovascular complications in diabetic and non-diabetic individuals. The aim of the study was to longitudinally investigate the association between the use of 11 vitamins and minerals (vitamins E, C, D, B1, folic acid, carotenoids, calcium, magnesium, zinc, iron, and selenium and change in HbA1c levels over 10 years in non-diabetic individuals drawn from the general population.Baseline data were available from 4447 subjects included in the population-based "Monitoring of Trends and Determinants in Cardiovascular Diseases" (MONICA Augsburg S3 survey (1994/95. Follow-up data were derived from 2774 participants in the follow-up survey named "Cooperative Health Research in the Region of Augsburg" (KORA F3 (2004/05. Vitamin/mineral intake from supplements and medications was assessed in a personal interview, where participants were asked to bring product packages of preparations that had been ingested during the last 7 days prior to the examination. Associations between regular vitamin/mineral intake amounts and HbA1c levels measured at baseline and follow-up were investigated using generalized estimating equation models. For carotenoids, analyses were stratified by smoking status.None of the investigated nutrients except for carotenoids was significantly associated with changes in HbA1c levels after 10 years. Regular intake of carotenoids from supplements and medications in amounts > 6.8 mg/d (upper tertile was associated with an absolute -0.26% (95% CI: -0.43 to -0.08 lower increase in HbA1c levels compared with no intake of carotenoids. An inverse association was observed in those who never smoked but not in (former smokers.Larger prospective and intervention studies in non-diabetic/non-smoking individuals are needed to confirm the results and to assess whether the observed associations between carotenoid intake and change in HbA1c levels are causal. If our results are

  3. On Longitudinal Spectral Coherence

    DEFF Research Database (Denmark)

    Kristensen, Leif

    1979-01-01

    It is demonstrated that the longitudinal spectral coherence differs significantly from the transversal spectral coherence in its dependence on displacement and frequency. An expression for the longitudinal coherence is derived and it is shown how the scale of turbulence, the displacement between...

  4. Longitudinal categorical data analysis

    CERN Document Server

    Sutradhar, Brajendra C

    2014-01-01

    This is the first book in longitudinal categorical data analysis with parametric correlation models developed based on dynamic relationships among repeated categorical responses. This book is a natural generalization of the longitudinal binary data analysis to the multinomial data setup with more than two categories. Thus, unlike the existing books on cross-sectional categorical data analysis using log linear models, this book uses multinomial probability models both in cross-sectional and longitudinal setups. A theoretical foundation is provided for the analysis of univariate multinomial responses, by developing models systematically for the cases with no covariates as well as categorical covariates, both in cross-sectional and longitudinal setups. In the longitudinal setup, both stationary and non-stationary covariates are considered. These models have also been extended to the bivariate multinomial setup along with suitable covariates. For the inferences, the book uses the generalized quasi-likelihood as w...

  5. Longitudinal beam dynamics

    CERN Document Server

    Tecker, F

    2014-01-01

    The course gives a summary of longitudinal beam dynamics for both linear and circular accelerators. After discussing different types of acceleration methods and synchronism conditions, it focuses on the particle motion in synchrotrons.

  6. Longitudinal Magnification Drawing Mistake

    Science.gov (United States)

    Rabal, Héctor; Cap, Nelly; Trivi, Marcelo

    2004-01-01

    Lateral magnification in image formation by positive lenses, mirrors, and dioptrics is usually appropriately developed in most optics textbooks.1-9 However, the image of a three-dimensional object occupies a three-dimensional region of space. The optical system affects both the transverse and the longitudinal dimensions of the object and, in general, does it in different ways. The magnification in the direction of the optical axis (the longitudinal magnification) is seldom treated. In several texts, the concept of longitudinal magnification is not even considered. Symmetrical objects (such as arrows) are used and their images appear laterally inverted. It is not shown how a longitudinally nonsymmetric object is imaged. One of the few books where this subject is well treated is in the textbook by Hecht.10 We have repeatedly verified in our classes that there is some confusion related to this subject. Students tend to believe that the image is longitudinally symmetric with respect to the lens optic center. Some prestigious texts commit the same mistake. In addition, a very nice optics book,11 a catalogue of optical hardware,12 a worldwide scientific magazine,13 a paper in an optics journal,14 and a Spanish encyclopedia,15 for example, have also been found to contain this error in drawing the image of a three-dimensional object formed by a positive lens. In this paper we suggest that the teaching of longitudinal magnification should be done with some care and we include a figure showing a properly drawn image.

  7. Non-communicable disease risk factor patterns among mining industry workers in Papua, Indonesia: longitudinal findings from the Cardiovascular Outcomes in a Papuan Population and Estimation of Risk (COPPER) Study

    OpenAIRE

    Rodriguez-Fernandez, Rodrigo; Rahajeng, Ekowati; Viliani, Francesca; Kushadiwijaya, Haripurnomo; Rachel M Amiya; Bangs, Michael J

    2015-01-01

    Objectives Non-communicable diseases (NCDs) constitute an increasing slice of the global burden of disease, with the South-East Asia region projected to see the highest increase in NCD-related deaths over the next decade. Mining industry employees may be exposed to various factors potentially elevating their NCD risk. This study aimed to assess the distribution and 5-year longitudinal trends of key metabolic NCD risk factors in a cohort of copper–gold mining company workers in Papua, Indonesi...

  8. Are Changes in Heart Rate Variability in Middle-Aged and Older People Normative or Caused by Pathological Conditions? Findings From a Large Population-Based Longitudinal Cohort Study.

    OpenAIRE

    Jandackova, V. K.; Scholes, S.; Britton, A.; Steptoe, A

    2016-01-01

    BACKGROUND: No study to date has investigated longitudinal trajectories of cardiac autonomic modulation changes with aging; therefore, we lack evidence showing whether these changes occur naturally or are secondary to disease or medication use. This study tested whether heart rate variability (HRV) trajectories from middle to older age are largely normative or caused by pathological changes with aging in a large prospective cohort. We further assessed whether HRV changes were modified by soci...

  9. Black carbon exposure more strongly associated with census tract poverty compared to household income among US black, white, and Latino working class adults in Boston, MA (2003–2010)

    International Nuclear Information System (INIS)

    We investigated the association of individual-level ambient exposure to black carbon (spatiotemporal model-based estimate for latitude and longitude of residential address) with individual, household, and census tract socioeconomic measures among a study sample comprised of 1757 US urban working class white, black and Latino adults (age 25–64) recruited for two studies conducted in Boston, MA (2003–2004; 2008–2010). Controlling for age, study, and exam date, the estimated average annual black carbon exposure for the year prior to study enrollment at the participants' residential address was directly associated with census tract poverty (beta = 0.373; 95% confidence interval (CI) 0.322, 0.423) but not with annual household income or education; null associations with race/ethnicity became significant only after controlling for socioeconomic position. - Highlights: • The study included 1757 black, Latino, and white working class adults in Boston, MA. • Census tract poverty was associated with annual average black carbon exposure. • Annual household income was not associated with black carbon exposure. • Individual-level education was not associated with black carbon exposure. • The observed socioeconomic patterns varied by race/ethnicity. - In a US multiethnic urban working adult population, exposure to black carbon was more strongly associated with census tract as compared to household- or individual-level socioeconomic measures

  10. Antedependence models for longitudinal data

    CERN Document Server

    Zimmerman, Dale L

    2009-01-01

    The First Book Dedicated to This Class of Longitudinal ModelsAlthough antedependence models are particularly useful for modeling longitudinal data that exhibit serial correlation, few books adequately cover these models. By gathering results scattered throughout the literature, Antedependence Models for Longitudinal Data offers a convenient, systematic way to learn about antedependence models. Illustrated with numerous examples, the book also covers some important statistical inference procedures associated with these models.After describing unstructured and structured antedependence models an

  11. Patterns of Multimorbidity in an Older Population of Persons with an Intellectual Disability: Results from the Intellectual Disability Supplement to the Irish Longitudinal Study on Aging (IDS-TILDA)

    Science.gov (United States)

    McCarron, Mary; Swinburne, Janet; Burke, Eilish; McGlinchey, Eimear; Carroll, Rachael; McCallion, Philip

    2013-01-01

    Multimorbidity (2 or more chronic conditions) is being widely studied in older populations and this study explores both the relevance of emerging conceptualizations and the extent to which multimorbidity is a feature of aging in persons with an intellectual disability. Methods: Data was generated from wave one of the intellectual disability…

  12. Loading Conditions and Longitudinal Strength

    DEFF Research Database (Denmark)

    Sørensen, Herman

    1995-01-01

    Methods for the calculation of the lightweight of the ship.Loading conditions satisfying draught, trim and intact stability requirements and analysis of the corresponding stillwater longitudinal strength.......Methods for the calculation of the lightweight of the ship.Loading conditions satisfying draught, trim and intact stability requirements and analysis of the corresponding stillwater longitudinal strength....

  13. Aging in Rett syndrome: a longitudinal study.

    Science.gov (United States)

    Halbach, N S J; Smeets, E E J; Steinbusch, C; Maaskant, M A; van Waardenburg, D; Curfs, L M G

    2013-09-01

    Little is known about the aging process of people with specific syndromes, like Rett syndrome (RTT). Recognition of the clinical and behavioral characteristics of the adult RTT is needed in order to improve future management of the RTT girl and counseling of parents. In association with the Dutch RTT parent association, a 5-year longitudinal study was carried out. The study population consisted of 53 adult women with a clinical diagnosis of RTT. Postal questionnaires were sent, including demographic features, skills, physical and psychiatric morbidity. At the time of the second measurement seven women had died. In 2012, 80% of the questionnaires (37/46) were returned. Mean age of the women was 31.4 years. Molecular confirmation was possible for 83% of the women for whom analyses were carried out. The adult RTT woman has a more or less stable condition. The general disorder profile is that of a slow on-going deterioration of gross motor functioning in contrast to a better preserved cognitive functioning, less autonomic and epileptic features and good general health. This is the first longitudinal cohort study about aging in RTT. Continuing longitudinal studies are needed to gain more insight into the aging process in RTT. PMID:23167724

  14. A Longitudinal Density Monitor for the LHC

    CERN Document Server

    Jeff, Adam; Boccardi, Andrea

    At the Large Hadron Collider (LHC), the world’s largest and highest energy particle accelerator, ion bunches circulate in two counter-rotating beams and are brought into collision. Each bunch is confined within a bucket by the longitudinal focusing effect of the radio frequency (RF) cavities. The RF period is 2.5 ns, while the minimum bunch spacing is 25 ns. Thus, 9 out of every 10 buckets should be empty, as well as additional gaps to allow for the rise-time of injection and dump kickers. In practice, however, small numbers of particles can occupy these supposedly empty buckets, causing problems for machine protection and for the absolute calibration of the LHC’s luminosity. The Longitudinal Density Monitor (LDM) is a new monitor, designed to measure the longitudinal distribution of particles in the LHC with a sufficiently high dynamic range to quantify the relative particle population in the supposedly empty buckets. A non-interceptive measurement is made possible by the use of synchrotron radiation (SR...

  15. What Alumni Value from New Product Development Education: A Longitudinal Study

    Science.gov (United States)

    Cobb, Corie L.; Hey, Jonathan; Agogino, Alice M.; Beckman, Sara L.; Kim, Sohyeong

    2016-01-01

    We present a longitudinal study of what graduates take away from a cross-disciplinary graduate-level New Product Development (NPD) course at UC Berkeley over a 15-year period from 1996-2010. We designed and deployed a longitudinal survey and interviewed a segment of our NPD alumni population to better understand how well our course prepared these…

  16. Black-white preterm birth disparity: a marker of inequality

    Science.gov (United States)

    Purpose. The racial disparity in preterrn birth (PTB) is a persistent feature of perinatal epidemiology, inconsistently modeled in the literature. Rather than include race as an explanatory variable, or employ race-stratified models, we sought to directly model the PTB disparity ...

  17. Theories about Black-White Interracial Marriage: A Clinical Perspective.

    Science.gov (United States)

    Davidson, Jeanette R.

    1992-01-01

    Directs attention to a number of theories about African-American-white interracial marriage found in the literature of the social sciences. Notes that theories suggest that couples who marry interracially generally have ulterior motives for doing so. Soundness of these theories is refuted, and suggestions are presented for clinicians working with…

  18. Components of Assertive Behavior: Are There Black-White Differences?

    Science.gov (United States)

    Lineberger, Marilyn Hazzard; Beezley, Dana

    Most definitions and training of assertive behavior fail to consider cultural diversity in social skills. Verbal, nonverbal and cognitive components of assertive behavior were investigated to determine cultural variations in assertiveness. Black (N=30) and white (N=30) male and female college students enacted 16 role-play scenes with 4 role…

  19. Understanding the Black-White School Discipline Gap

    Science.gov (United States)

    Kinsler, Josh

    2011-01-01

    At state and national levels, black students are more likely to be suspended from school, and conditional on misbehavior, receive stiffer penalties when compared with white students. Racial bias is often cited as a primary contributor to these gaps. Using infraction data from North Carolina, I investigate gaps in punishment within and across…

  20. Nucleic Acid Charge Transfer: Black, White and Gray

    OpenAIRE

    Venkatramani, Ravindra; Keinan, Shahar; Balaeff, Alexander; Beratan, David N.

    2011-01-01

    Theoretical studies of charge transport in deoxyribonucleic acid (DNA) and peptide nucleic acid (PNA) indicate that structure and dynamics modulate the charge transfer rates, and that different members of a structural ensemble support different charge transport mechanisms. Here, we review the influences of nucleobase geometry, electronic structure, solvent environment, and thermal conformational fluctuations on the charge transfer mechanism. We describe an emerging framework for understanding...

  1. Response rates and selection problems, with emphasis on mental health variables and DNA sampling, in large population-based, cross-sectional and longitudinal studies of adolescents in Norway

    Directory of Open Access Journals (Sweden)

    Lien Lars

    2010-10-01

    Full Text Available Abstract Background Selection bias is a threat to the internal validity of epidemiological studies. In light of a growing number of studies which aim to provide DNA, as well as a considerable number of invitees who declined to participate, we discuss response rates, predictors of lost to follow-up and failure to provide DNA, and the presence of possible selection bias, based on five samples of adolescents. Methods We included nearly 7,000 adolescents from two longitudinal studies of 18/19 year olds with two corresponding cross-sectional baseline studies at age 15/16 (10th graders, and one cross-sectional study of 13th graders (18/19 years old. DNA was sampled from the cheek mucosa of 18/19 year olds. Predictors of lost to follow-up and failure to provide DNA were studied by Poisson regression. Selection bias in the follow-up at age 18/19 was estimated through investigation of prevalence ratios (PRs between selected exposures (physical activity, smoking and outcome variables (general health, mental distress, externalizing problems measured at baseline. Results Out of 5,750 who participated at age 15/16, we lost 42% at follow-up at age 18/19. The percentage of participants who gave their consent to DNA provision was as high as the percentage that consented to a linkage of data with other health registers and surveys, approximately 90%. Significant predictors of lost to follow-up and failure to provide DNA samples in the present genetic epidemiological study were: male gender; non-western ethnicity; postal survey compared with school-based; low educational plans; low education and income of father; low perceived family economy; unmarried parents; poor self-reported health; externalized symptoms and smoking, with some differences in subgroups of ethnicity and gender. The association measures (PRs were quite similar among participants and all invitees, with some minor discrepancies in subgroups of non-western boys and girls. Conclusions Lost to

  2. Pain Perceptions of the Oldest Old: A Longitudinal Study

    Science.gov (United States)

    Zarit, Steven H.; Griffiths, Patricia C.; Berg, Stig

    2004-01-01

    Purpose: This study assessed self-reported pain in the oldest old and examined its changes over time and in relation to other measures of health and functioning. Design and Methods: A population-based sample of the oldest old (86-92 years of age) residing in Sweden who were participating in a multiwave longitudinal investigation were interviewed…

  3. Modeling Longitudinal Data Containing Non-Normal Within Subject Errors

    Science.gov (United States)

    Feiveson, Alan; Glenn, Nancy L.

    2013-01-01

    The mission of the National Aeronautics and Space Administration’s (NASA) human research program is to advance safe human spaceflight. This involves conducting experiments, collecting data, and analyzing data. The data are longitudinal and result from a relatively few number of subjects; typically 10 – 20. A longitudinal study refers to an investigation where participant outcomes and possibly treatments are collected at multiple follow-up times. Standard statistical designs such as mean regression with random effects and mixed–effects regression are inadequate for such data because the population is typically not approximately normally distributed. Hence, more advanced data analysis methods are necessary. This research focuses on four such methods for longitudinal data analysis: the recently proposed linear quantile mixed models (lqmm) by Geraci and Bottai (2013), quantile regression, multilevel mixed–effects linear regression, and robust regression. This research also provides computational algorithms for longitudinal data that scientists can directly use for human spaceflight and other longitudinal data applications, then presents statistical evidence that verifies which method is best for specific situations. This advances the study of longitudinal data in a broad range of applications including applications in the sciences, technology, engineering and mathematics fields.

  4. Longitudinal Vortices in Granular Flows

    OpenAIRE

    Forterre, Yoel; Pouliquen, Olivier

    2001-01-01

    We present a new instability observed in rapid granular flows down rough inclined planes. For high inclinations and flow rates, the free surface of the flow experiences a regular deformation in the transverse direction. Measurements of the surface velocities imply that this instability is associated with the formation of longitudinal vortices in the granular flow. From the experimental observations, we propose a mechanism for the longitudinal vortex formation based on the concept of granular ...

  5. Immigrant earnings: a longitudinal analysis

    OpenAIRE

    Chiswick, Barry R; Lee, Yew Liang; Paul W. Miller

    2005-01-01

    This paper uses the Longitudinal Survey of Immigrants to Australia to analyze the determinants of the level and growth in earnings of adult male immigrants in their first 3.5 years in Australia. The theoretical framework is based on the immigrant adjustment model, which incorporates both the transferability of immigrant skills and selectively in migration. The cross-sectional and longitudinal analyses generate similar findings. The level and relative growth of earnings are higher for immigran...

  6. Summary of longitudinal instabilities workshop

    International Nuclear Information System (INIS)

    A five-day ISABELLE workshop on longitudinal instabilities was held at BNL, August 9--13, 1976. Heavy emphasis was put on single bunched beam instabilities in the microwave region extending above the cut-off frequency of the ISABELLE vacuum chamber. A discussion is given of the mechanism governing the instability, and calculations as well as measurements of the longitudinal coupling impedances in the ISABELLE rings are described

  7. Relationship of Self-Rated Health to Stroke Incidence and Mortality in Older Individuals with and without a History of Stroke: A Longitudinal Study of the MRC Cognitive Function and Ageing (CFAS Population.

    Directory of Open Access Journals (Sweden)

    Nahal Mavaddat

    Full Text Available Poor self-rated health (SRH has been associated with increased risk of death and poor health outcomes even after adjusting for confounders. However its' relationship with disease-specific mortality and morbidity has been less studied. SRH may also be particularly predictive of health outcomes in those with pre-existing conditions. We studied whether SRH predicts new stroke in older people who have never had a stroke, or a recurrence in those with a prior history of stroke.MRC CFAS I is a multicentre cohort study of a population representative sample of people in their 65th year and older. A comprehensive interview at baseline included questions about presence of stroke, self-rated health and functional disability. Follow-up at 2 years included self-report of stroke and stroke death obtained from death certificates. Multiple logistical regression determined odds of stroke at 2 years adjusting for confounders including disability and health behaviours. Survival analysis was performed until June 2014 with follow-up for up to 13 years.11,957 participants were included, of whom 11,181 (93.8% had no history of stroke and 776 (6.2% one or more previous strokes. Fewer with no history of stroke reported poor SRH than those with stroke (5 versus 21%. In those with no history of stroke, poor self-rated health predicted stroke incidence (OR 1.5 (1.1-1.9, but not stroke mortality (OR 1.2 (0.8-1.9 at 2 years nor for up to 13 years (OR 1.2(0.9-1.7. In those with a history of stroke, self-rated health did not predict stroke incidence (OR 0.9(0.6-1.4, stroke mortality (OR 1.1(0.5-2.5, or survival (OR 1.1(0.6-2.1.Poor self-rated health predicts risk of stroke at 2 years but not stroke mortality among the older population without a previous history of stroke. SRH may be helpful in predicting who may be at risk of developing a stroke in the near future.

  8. Functional Status After Injury: A Longitudinal Study of Geriatric Trauma

    OpenAIRE

    Kelley-Quon, Lorraine; Min, Lillian; Morley, Eric; Hiatt, Jonathan R; Cryer, Henry; Tillou, Areti

    2010-01-01

    We evaluated self-rated functional status measured longitudinally in the year following injury in a geriatric trauma population. The Longitudinal (L) group included 37 of 60 eligible trauma patients age ≥ 65 years admitted December 2006-November 2007 for > 24 hours who completed a Short Functional Status questionnaire (SFS) at 3, 6, and 12 months after injury. The SFS yields scores of 0-5 (5=independent in all five activities of daily living, ADLs) and has been validated among community-dwell...

  9. The Prognostic Value of Left Atrial Peak Reservoir Strain in Acute Myocardial Infarction Is Dependent on Left Ventricular Longitudinal Function and Left Atrial Size

    DEFF Research Database (Denmark)

    Ersbøll, Mads; Andersen, Mads J; Valeur, Nana;

    2013-01-01

    Peak atrial longitudinal strain (PALS) during the reservoir phase has been proposed as a measure of left atrium function in a range of cardiac conditions, with the potential for added pathophysiological insight and prognostic value. However, no studies have assessed the interrelation of PALS...... and left ventricular longitudinal strain (global longitudinal strain) in large-scale populations in regard to prognosis....

  10. Impacto de la morbilidad, uso de recursos y costes en el mantenimiento de la remisión de la depresión mayor en España: estudio longitudinal de ámbito poblacional Impact of morbidity, resource use and costs on maintenance of remission of major depression in Spain: a longitudinal study in a population setting

    Directory of Open Access Journals (Sweden)

    Antoni Sicras-Mainar

    2010-01-01

    Full Text Available Objetivo: Determinar el impacto de la comorbilidad, el uso de recursos y los costes (sanitarios y en pérdidas de productividad laboral en el mantenimiento de la remisión de la depresión en un ámbito poblacional español. Métodos: Diseño observacional, prospectivo, multicéntrico, realizado con bases de datos poblacionales. Los criterios de inclusión fueron: edad >18 años, inicio del episodio depresivo entre enero de 2003 y marzo de 2007, prescripción de antidepresivos >60 días después de la primera prescripción y duración del seguimiento de 18 meses (estudio: 12 meses; continuación: 6 meses. Se consideraron 2 subgrupos: pacientes en remisión y sin remisión. Las principales mediciones fueron sociodemográficas, episodios, bandas de utilización de recursos, costes sanitarios (directos y en pérdidas de productividad (indirectos. Se realizó análisis de regresión logística y de análisis de la covarianza (ajuste Bonferroni. Resultados: Se reclutaron 4.572 sujetos. El 54,6% (intervalo de confianza del 95%: 53,2-56,0% se consideraron en remisión. Los pacientes en remisión mostraron menor edad (52,6 frente a 60,7 años, mayor proporción de mujeres (71,7% frente a 78,2%, más morbilidad general (6,2 frente a 7,7 episodios/año, menos bandas de utilización de recursos/año (2,7 frente a 3,0, menor incapacidad laboral (31,0 frente a 38,5 días y menor duración del tratamiento antidepresivo (146,6 frente a 307,7 días; pObjective: To determinate the impact of comorbidity, resource use and cost (healthcare and lost productivity on maintenance of remission of major depressive disorder in a Spanish population setting. Methods: We performed an observational, prospective, multicenter study using population databases. The inclusion criteria were age >18 years, first depressive episode between January 2003 and March 2007, with antidepressant prescription >60 days after the first prescription and a follow-up of at least 18 months (study

  11. Longitudinal Predictors of Institutionalization in Old Age

    Science.gov (United States)

    Hajek, André; Brettschneider, Christian; Lange, Carolin; Posselt, Tina; Wiese, Birgitt; Steinmann, Susanne; Weyerer, Siegfried; Werle, Jochen; Pentzek, Michael; Fuchs, Angela; Stein, Janine; Luck, Tobias; Bickel, Horst; Mösch, Edelgard; Wagner, Michael; Jessen, Frank; Maier, Wolfgang; Scherer, Martin

    2015-01-01

    Objective To investigate time-dependent predictors of institutionalization in old age using a longitudinal approach. Methods In a representative survey of the German general population aged 75 years and older predictors of institutionalization were observed every 1.5 years over six waves. Conditional fixed-effects logistic regressions (with 201 individuals and 960 observations) were performed to estimate the effects of marital status, depression, dementia, and physical impairments (mobility, hearing and visual impairments) on the risk of admission to old-age home or nursing home. By exploiting the longitudinal data structure using panel econometric models, we were able to control for unobserved heterogeneity such as genetic predisposition and personality traits. Results The probability of institutionalization increased significantly with occurrence of widowhood, depression, dementia, as well as walking and hearing impairments. In particular, the occurrence of widowhood (OR = 78.3), dementia (OR = 154.1) and substantial mobility impairment (OR = 36.7) were strongly associated with institutionalization. Conclusion Findings underline the strong influence of loss of spouse as well as dementia on institutionalization. This is relevant as the number of old people (a) living alone and (b) suffering from dementia is expected to increase rapidly in the next decades. Consequently, it is supposed that the demand for institutionalization among the elderly will increase considerably. Practitioners as well as policy makers should be aware of these upcoming challenges. PMID:26658776

  12. Longitudinal Wobbling in $^{133}$La

    CERN Document Server

    Biswas, S; Garg, U; Bhat, G H; Frauendorf, S; Li, W; Sheikh, J A; Sethi, J; Saha, S; Singh, Purnima; Choudhury, D; Matta, J T; Ayangeakaa, A D; Dar, W >; Singh, V; Sihotra, S

    2016-01-01

    Excited states of $^{133}$La have been investigated to search for the wobbling excitation mode in the low-spin regime. Wobbling bands with $n_\\omega$ = 0 and 1 are identified along with the interconnecting $\\Delta I$ = 1, $E2$ transitions, which are regarded as fingerprints of the wobbling motion. An increase in wobbling frequency %of the $n_\\omega$ = 1 band with spin implies longitudinal wobbling for $^{133}$La, in contrast with the case of transverse wobbling observed in $^{135}$Pr. This is the first observation of a longitudinal wobbling band in nuclei. The experimental observations are accounted for by calculations using the quasiparticle triaxial rotor with harmonic frozen approximation and the triaxial projected shell model approaches, which attribute the appearance of longitudinal wobbling to the early alignment of an h$_{11/2}$ neutron pair.

  13. Longitudinal compression of ion beams

    International Nuclear Information System (INIS)

    This paper examines the longitudinal compression of ion beams which is necessary in some designs of drivers intended to realize inertial thermonuclear fusion by heavy ions. Taking space-charge forces in the beams into account, two compression schemes are investigated: the first preserves the longitudinal phase-space area of the beams, and the second allows an increase of the phase-space area. The compression-system parameters are optimized for an example of a driver for inertial thermonuclear fusion by heavy ions with an energy of 10 MJ and with a pulse length of 25 ns on the target

  14. Longitudinal feedback system for PEP

    Energy Technology Data Exchange (ETDEWEB)

    Allen, M.A.; Cornacchia, M.; Millich, A.

    1979-02-01

    Whether the wide bandwidth longitudinal feedback system described in this paper is made to act on the individual modes in frequency domain or on the individual bunches in time domain, it represents a clean and efficient way of damping the longitudinal oscillations without influencing other beam parameters such as bunch shape or synchrotron frequency distribution. The frequency domain feedback presents the advantage of providing information on which modes are unstable and on their risetimes, which may be helpful in locating dangerous resonators in the ring.

  15. Longitudinal and Transverse Nuclear Shadowing

    OpenAIRE

    Barone, V.; M.; Genovese

    1996-01-01

    Nuclear shadowing arises from multiple scattering of the hadronic fluctuations of the virtual photon in a nucleus. We predict different longitudinal and transverse shadowing and an A-dependence of R which can be up to a 50% effect. The possibility of detecting nuclear effects on R at HERA is discussed.

  16. Correspondence analysis of longitudinal data

    NARCIS (Netherlands)

    Van der Heijden, P.G.M.

    2005-01-01

    Correspondence analysis is an exploratory tool for the analysis of associations between categorical variables, the results of which may be displayed graphically. For longitudinal data with two time points, an analysis of the transition matrix (showing the relative frequencies for pairs of categories

  17. Longitudinal bulk acoustic mass sensor

    DEFF Research Database (Denmark)

    Hales, Jan Harry; Teva, Jordi; Boisen, Anja;

    2009-01-01

    A polycrystalline silicon longitudinal bulk acoustic cantilever is fabricated and operated in air at 51 MHz. A mass sensitivity of 100 Hz/fg (1 fg=10(-15) g) is obtained from the preliminary experiments where a minute mass is deposited on the device by means of focused ion beam. The total noise i...

  18. Exploring longitudinal pathways from intelligence to morbidity and mortality risk

    OpenAIRE

    Calvin, Catherine Mary

    2012-01-01

    Human population-based studies of longitudinal design observe that higher intelligence in youth confers protection from premature mortality in adulthood. This field of study (“cognitive epidemiology”; Deary & Batty, 2007) has firmly established associations between intelligence and health outcomes, and has begun to address the likely mechanisms involved. The present thesis assessed some social, educational, and lifestyle factors that potentially confound and/or mediate the i...

  19. Paediatric UK demyelinating disease longitudinal study (PUDDLS

    Directory of Open Access Journals (Sweden)

    Likeman Marcus

    2011-07-01

    Full Text Available Abstract Background There is evidence that at least 5% of Multiple sclerosis (MS cases manifest in childhood. Children with MS present with a demyelinating episode involving single or multiple symptoms prior to developing a second event (usually within two years to then meet criteria for diagnosis. There is evidence from adult cohorts that the incidence and sex ratios of MS are changing and that children of immigrants have a higher risk for developing MS. A paediatric population should reflect the vanguard of such changes and may reflect trends yet to be observed in adult cohorts. Studying a paediatric population from the first demyelinating event will allow us to test these hypotheses, and may offer further valuable insights into the genetic and environmental interactions in the pathogenesis of MS. Methods/Design The Paediatric UK Demyelinating Disease Longitudinal Study (PUDDLS is a prospective longitudinal observational study which aims to determine the natural history, predictors and outcomes of childhood CNS inflammatory demyelinating diseases. PUDDLS will involve centres in the UK, and will establish a cohort of children affected with a first CNS inflammatory demyelinating event for long-term follow up by recruiting for approximately 5 years. PUDDLS will also establish a biological sample archive (CSF, serum, and DNA, allowing future hypothesis driven research. For example, the future discovery of a biomarker will allow validation within this dataset for the evaluation of novel biomarkers. Patients will also be requested to consent to be contacted in the future. A secondary aim is to collaborate internationally with the International Paediatric Multiple Sclerosis Study Group when future collaborative studies are proposed, whilst sharing a minimal anonymised dataset. PUDDLS is the second of two jointly funded studies. The first (UCID-SS is an epidemiological surveillance study that already received ethical approvals, and started on the 1st

  20. Exploring Longitudinal Risk-return Relationships

    DEFF Research Database (Denmark)

    Andersen, Torben J.; Bettis, Richard A.

    2015-01-01

    We study a longitudinal fit model of adaptation and its association with the longitudinal risk-return relationship. The model allows the firm to adjust its position in response to partial learning about a changing environment characterized by two path-dependent processes—a random walk...... can lead to the inverse longitudinal risk-return relationships observed empirically. We discuss this apparent paradox and the possible resolution between mindless and conscious behavior as plausible causes of the longitudinal Bowman Paradox....

  1. Loss and gain cycles? A longitudinal study about burnout, engagement and self-efficacy

    OpenAIRE

    Susana Llorens-Gumbau; Marisa Salanova-Soria

    2014-01-01

    The present longitudinal study (two waves), conducted on a population of 274 secondary-school teachers, expands on previous research on burnout and work engagement. Accordingly, the effect of organizational factors (obstacles, facilitators) as well as personal resources (self-efficacy) on burnout and engagement is tested longitudinally following the Social Cognitive Theory. More specifically, we test the loss and gain cycles, and reciprocal relationships concerning burnout, engagement, and se...

  2. The Importance of Longitudinal Studies

    Science.gov (United States)

    Knezek, Patricia

    2014-01-01

    It has been eight years since the AAS Council unanimously endorsed the document, known as "Equity Now: The Pasadena Recommendations for Gender Equality in Astronomy," in January 2005. This document was the main product of the conference entitled “Women in Astronomy II: Ten Years After” (WIA II), held in June 2003 in Pasadena, CA. One of the key recommendations represented in that document was the need for a longitudinal study of astronomers. It was recognized that in order to understand our own field, how it is evolving, and the impact on individuals, we need to track people over time. I will discuss the fundamental questions that led to the recommendation, and set the stage for the current (ongoing) longitudinal study.

  3. Longitudinal misalignment based strain sensor

    OpenAIRE

    Andrews, Jeffrey Pratt

    1989-01-01

    A practical fiber optic strain sensor has been developed to measure strains in the range of 0.0 to 2.0 percent strain with a resolution ranging between 10 and 100 microstrain depending on sensor design choices. This intensity based sensor measures strain by monitoring strain induced longitudinal misalignment in a novel fiber interconnection. This interconnection is created by aligning fibers within a segment of hollow core fiber. Related splice loss mechanisms are investigated ...

  4. Socio-demographic and lifestyle factors for child’s physical growth and adiposity rebound of Japanese children: a longitudinal study of the 21st century longitudinal survey in newborns

    OpenAIRE

    Franchetti, Yoko; Ide, Hiroo

    2014-01-01

    Background: It is unknown whether childhood physical development in Asian populations differs from western populations, since no longitudinal analysis has been performed in Asian countries yet. Utilizing the 21st Century Longitudinal Survey in Newborns, we studied the timing of adiposity rebound (AR) among Japanese children and determined whether AR occurs earlier in obese children compared to nonobese children. Furthermore, we identified important demographic, social, and lifestyle factors t...

  5. Socio-demographic and lifestyle factors for child’s physical growth and adiposity rebound of Japanese children: a longitudinal study of the 21st century longitudinal survey in newborns

    OpenAIRE

    Franchetti, Yoko; Ide, Hiroo

    2014-01-01

    Background It is unknown whether childhood physical development in Asian populations differs from western populations, since no longitudinal analysis has been performed in Asian countries yet. Utilizing the 21st Century Longitudinal Survey in Newborns, we studied the timing of adiposity rebound (AR) among Japanese children and determined whether AR occurs earlier in obese children compared to nonobese children. Furthermore, we identified important demographic, social, and lifestyle factors th...

  6. Parameterized Linear Longitudinal Airship Model

    Science.gov (United States)

    Kulczycki, Eric; Elfes, Alberto; Bayard, David; Quadrelli, Marco; Johnson, Joseph

    2010-01-01

    A parameterized linear mathematical model of the longitudinal dynamics of an airship is undergoing development. This model is intended to be used in designing control systems for future airships that would operate in the atmospheres of Earth and remote planets. Heretofore, the development of linearized models of the longitudinal dynamics of airships has been costly in that it has been necessary to perform extensive flight testing and to use system-identification techniques to construct models that fit the flight-test data. The present model is a generic one that can be relatively easily specialized to approximate the dynamics of specific airships at specific operating points, without need for further system identification, and with significantly less flight testing. The approach taken in the present development is to merge the linearized dynamical equations of an airship with techniques for estimation of aircraft stability derivatives, and to thereby make it possible to construct a linearized dynamical model of the longitudinal dynamics of a specific airship from geometric and aerodynamic data pertaining to that airship. (It is also planned to develop a model of the lateral dynamics by use of the same methods.) All of the aerodynamic data needed to construct the model of a specific airship can be obtained from wind-tunnel testing and computational fluid dynamics

  7. Reconciling cross-sectional with longitudinal observations on annual decline.

    Science.gov (United States)

    Vollmer, W M

    1993-01-01

    In summary, numerous factors may contribute to observed differences between longitudinally and cross-sectionally derived measures of annual decline in lung function. The direction and magnitude of these differences appear hard to predict. Furthermore, although these differences can be minimized by careful modeling of the data, they cannot, in general, be completely avoided. It seems plausible, however, that both types of studies should give similar qualitative comparisons of risk factor effects if appropriately modeled. Longitudinal studies are likely to provide the most accurate and reliable estimates of lung function decline for both individuals and populations. Such data may be especially useful in identifying individuals with accelerated declines in lung function but who still have "normal" lung function as measured cross-sectionally. However, such studies require careful attention to quality control and typically require at least 4 years of follow-up before the noise in the data settles down. Multiple measurements, preferably four or more, are also necessary to reliably detect and adjust for survey effects. Cross-sectional studies, on the other hand, are simpler, cheaper, and quicker to conduct than are longitudinal studies. They may be particularly useful as a screening tool for identifying potentially affected or high-risk subjects (e.g., those with low levels of lung function) who may require further medical follow-up and/or ongoing monitoring. Both types of studies have a role in population-based occupational health hazard assessments.

  8. Transverse and longitudinal vibrations in amorphous silicon

    OpenAIRE

    Beltukov, Y. M.; De Fusco, C; Tanguy, A.; Parshin, D. A.

    2015-01-01

    We show that harmonic vibrations in amorphous silicon can be decomposed to transverse and longitudinal components in all frequency range even in the absence of the well defined wave vector ${\\bf q}$. For this purpose we define the transverse component of the eigenvector with given $\\omega$ as a component, which does not change the volumes of Voronoi cells around atoms. The longitudinal component is the remaining orthogonal component. We have found the longitudinal and transverse components of...

  9. A Longitudinal Study of the Effects of Family Background Factors on Mathematics Achievements Using Quantile Regression

    Institute of Scientific and Technical Information of China (English)

    Xi-zhi Wu; Mao-zai Tian

    2008-01-01

    Quantile regression is gradually emerging as a powerful tool for estimating models of conditional quantile functions, and therefore research in this area has vastly increased in the past two decades. This paper, with the quantile regression technique, is the first comprehensive longitudinal study on mathematics participation data collected in Alberta, Canada. The major advantage of longitudinal study is its capability to separate the so-called cohort and age effects in the context of population studies. One aim of this paper is to study whether the family background factors alter performance on the mathematical achievement of the strongest students in the same way as that of weaker students based on the large longitudinal sample of 2000,2001 and 2002 mathematics participation longitudinal data set. The interesting findings suggest that there may be differential family background factor effects at different points in the mathematical achievement conditional distribution.

  10. Modeling of longitudinal polytomous outcome from complex survey data - application to investigate an association between mental distress and non-malignant respiratory diseases

    OpenAIRE

    Pahwa Punam; Karunanayake Chandima P

    2009-01-01

    Abstract Background The data from longitudinal complex surveys based on multi-stage sampling designs contain cross-sectional dependencies among units due to clustered nature of the data and within-subject dependencies due to repeated measurements. Special statistical methods are required to analyze longitudinal complex survey data. Methods Statistics Canada's longitudinal National Population Health Survey (NPHS) dataset from the first five cycles (1994/1995 to 2002/2003) was used to investiga...

  11. Introduction to Longitudinal Beam Dynamics

    CERN Document Server

    Holzer, B J

    2014-01-01

    This chapter gives an overview of the longitudinal dynamics of the particles in an accelerator and, closely related to that, the issue of synchronization between the particles and the accelerating field. Beginning with the trivial case of electrostatic accelerators, the synchronization condition is explained for a number of driven accelerators like Alvarez linacs, cyclotrons and finally synchrotrons and storage rings, where it plays a crucial role. In the case of the latter, the principle of phase focusing is motivated qualitatively as well as on a mathematically more correct level and the problem of operation below and above the transition energy is discussed. Throughout, the main emphasis is more on physical understanding rather than on a mathematically rigorous treatment.

  12. Fears in Czech Adolescents: A Longitudinal Study

    Science.gov (United States)

    Michalcáková, Radka; Lacinová, Lenka; Kyjonková, Hana; Bouša, Ondrej; Jelínek, Martin

    2013-01-01

    The present study investigates developmental patterns of fear in adolescence. It is based on longitudinal data collected as a part of the European Longitudinal Study of Pregnancy and Childhood (ELSPAC) project. A total of 186 Czech adolescents (43% girls) were assessed repeatedly at the age of 11, 13, and 15 years. The free-response method was…

  13. Modeling a Longitudinal Relational Research Data Systems

    Science.gov (United States)

    Olsen, Michelle D. Hunt

    2010-01-01

    A study was conducted to propose a research-based model for a longitudinal data research system that addressed recommendations from a synthesis of literature related to: (1) needs reported by the U.S. Department of Education, (2) the twelve mandatory elements that define federally approved state longitudinal data systems (SLDS), (3) the…

  14. Transverse and longitudinal vibrations in amorphous silicon

    Science.gov (United States)

    Beltukov, Y. M.; Fusco, C.; Tanguy, A.; Parshin, D. A.

    2015-12-01

    We show that harmonic vibrations in amorphous silicon can be decomposed to transverse and longitudinal components in all frequency range even in the absence of the well defined wave vector q. For this purpose we define the transverse component of the eigenvector with given ω as a component, which does not change the volumes of Voronoi cells around atoms. The longitudinal component is the remaining orthogonal component. We have found the longitudinal and transverse components of the vibrational density of states for numerical model of amorphous silicon. The vibrations are mostly transverse below 7 THz and above 15 THz. In the frequency interval in between the vibrations have a longitudinal nature. Just this sudden transformation of vibrations at 7 THz from almost transverse to almost longitudinal ones explains the prominent peak in the diffusivity of the amorphous silicon just above 7 THz.

  15. LSTGEE: longitudinal analysis of neuroimaging data

    Science.gov (United States)

    Li, Yimei; Zhu, Hongtu; Chen, Yasheng; An, Hongyu; Gilmore, John; Lin, Weili; Shen, Dinggang

    2009-02-01

    Longitudinal imaging studies are essential to understanding the neural development of neuropsychiatric disorders, substance use disorders, and normal brain. Using appropriate image processing and statistical tools to analyze the imaging, behavioral, and clinical data is critical for optimally exploring and interpreting the findings from those imaging studies. However, the existing imaging processing and statistical methods for analyzing imaging longitudinal measures are primarily developed for cross-sectional neuroimaging studies. The simple use of these cross-sectional tools to longitudinal imaging studies will significantly decrease the statistical power of longitudinal studies in detecting subtle changes of imaging measures and the causal role of time-dependent covariate in disease process. The main objective of this paper is to develop longitudinal statistics toolbox, called LSTGEE, for the analysis of neuroimaging data from longitudinal studies. We develop generalized estimating equations for jointly modeling imaging measures with behavioral and clinical variables from longitudinal studies. We develop a test procedure based on a score test statistic and a resampling method to test linear hypotheses of unknown parameters, such as associations between brain structure and function and covariates of interest, such as IQ, age, gene, diagnostic groups, and severity of disease. We demonstrate the application of our statistical methods to the detection of the changes of the fractional anisotropy across time in a longitudinal neonate study. Particularly, our results demonstrate that the use of longitudinal statistics can dramatically increase the statistical power in detecting the changes of neuroimaging measures. The proposed approach can be applied to longitudinal data with multiple outcomes and accommodate incomplete and unbalanced data, i.e., subjects with different number of measurements.

  16. Longitudinal research and data collection in primary care

    NARCIS (Netherlands)

    Weel, C. van

    2005-01-01

    PURPOSE: This article reviews examples of and experience with longitudinal research in family medicine. The objective is to use this empirical information to formulate recommendations for improving longitudinal research. METHODS: The article discusses 3 longitudinal studies from the Nijmegen academi

  17. Untreated periodontal disease in Indonesian adolescents : Longitudinal clinical data and prospective clinical and microbiological risk assessment

    NARCIS (Netherlands)

    Timmerman, MF; Van der Weijden, GA; Abbas, F; Arief, EM; Armand, S; Winkel, EG; Van Winkelhoff, AJ; Van der Velden, U

    2000-01-01

    Background, aims: In order to investigate the role of various putative clinical and microbiological risk markers, a longitudinal study was initiated in a young population deprived of regular dental care. In 1987 all inhabitants in the age range 15-25 years living in a village with approximately 2000

  18. Analysis of Apprenticeship Training from the National Longitudinal Study of the High School Class of 1972.

    Science.gov (United States)

    Cook, Robert F.; And Others

    A study investigated effects of on-the-job or "hands-on" vocational training relative to standard classroom vocational instruction on subsequent employment, earnings, wages, and job satisfaction. The data used were from the National Longitudinal Study of the High School Class of 1972 and five follow-up surveys of this population. An analysis of…

  19. A longitudinal twin study of the direction of effects between ADHD symptoms and IQ

    NARCIS (Netherlands)

    Rommel, A.S.; Rijsdijk, F.; Greven, C.U.; Asherson, P.; Kuntsi, J.

    2015-01-01

    While the negative association between ADHD symptoms and IQ is well documented, our knowledge about the direction and aetiology of this association is limited. Here, we examine the association of ADHD symptoms with verbal and performance IQ longitudinally in a population-based sample of twins. In a

  20. Violence against Pregnant Women Can Increase the Risk of Child Abuse: A Longitudinal Study

    Science.gov (United States)

    Chan, Ko Ling; Brownridge, Douglas A.; Fong, Daniel Y. T.; Tiwari, Agnes; Leung, Wing Cheong; Ho, Pak Chung

    2012-01-01

    Objective: To assess the impact of intimate partner violence (IPV) against pregnant women on subsequent perpetration of child abuse and neglect (CAN) by parents; and to test the mediation effect of recent IPV on the link between IPV during pregnancy and subsequent CAN. Methods: This study was a longitudinal follow-up of a population-based study on…

  1. Unveiling the Longitudinal Association between Short Sleep Duration and the Incidence of Obesity: the Penn State Cohort

    OpenAIRE

    Vgontzas, Alexandros N.; Fernandez-Mendoza, Julio; Miksiewicz, Tory; Kritikou, Ilia; Shaffer, Michele L.; Liao, Duanping; Basta, Maria; Bixler, Edward O.

    2013-01-01

    Objective Several epidemiologic, longitudinal studies have reported that short sleep duration is a risk factor for the incidence of obesity. However, the vast majority of these studies used self-reported measures of sleep duration and did not examine the role of objective short sleep duration, subjective sleep disturbances, and emotional stress. Design Longitudinal, population-based study. Subjects We studied a random sample of 815 non-obese adults from the Penn State Cohort in the sleep labo...

  2. Longitudinal Variations in Jupiter's Winds

    Science.gov (United States)

    Simon-Miller, Amy A.; Gierasch, P. J.; Tierney, G.

    2010-01-01

    Long-term studies of Jupiter's zonal wind field revealed temporal variations on the order of 20 to 40 m/s at many latitudes, greater than the typical data uncertainties of 1 to 10 m/s. No definitive periodicities were evident, however, though some latitudinally-confined signals did appear at periods relevant to the Quasi- Quadrennial Oscillation (Simon-Miller & Gierasch, Icarus, in press). As the QQO appears, from vertical temperature profiles, to propagate downward, it is unclear why a signal is not more obvious, unless other processes dominate over possibly weaker forcing from the QQO. An additional complication is that zonal wind profiles represent an average over some particular set of longitudes for an image pair and most data sets do not offer global wind coverage. Lien avoiding known features, such as the large anticyclonic vortices especially prevalent in the south, there can be distinct variations in longitude. We present results on the full wind field from Voyager and Cassini data, showing apparent longitudinal variations of up to 60 m/s or more. These are particularly obvious near disruptions such as the South Equatorial Disturbance, even when the feature itself is not clearly visible. These two dates represent very different states of the planet for comparison: Voyagers 1 & 2 flew by Jupiter shortly after a global upheaval, while many regions were in a disturbed state, while the Cassini view is typical of a more quiescent period present during much of the 1990s and early 2000s.

  3. Longitudinal dynamics and tomography in the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Stogin, J. [Princeton Univ., Princeton, NJ (United States); Sen, T. [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); Moore, R. S. [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)

    2012-01-10

    Motivated by the desire to understand the longitudinal effects of beam-beam forces, we study the longitudinal dynamics of protons and anti-protons at injection and top energy in the Tevatron. Multi-turn data of the longitudinal profiles are captured to reveal information about frequencies of oscillation, and changes in the bunch distributions. Tomographic reconstruction is used to create phase space maps which are subsequently used to find the momentum distributions. Changes in these distributions for both proton and anti-proton beams are also followed through the operational cycle. We report too on the details of interesting dynamics and some unexpected findings.

  4. Longitudinal Study: Efficacy of Online Technology Tools for Instructional Use

    Science.gov (United States)

    Uenking, Michael D.

    2011-01-01

    Studies show that the student population (secondary and post secondary) is becoming increasingly more technologically savvy. Use of the internet, computers, MP3 players, and other technologies along with online gaming has increased tremendously amongst this population such that it is creating an apparent paradigm shift in the learning modalities of these students. Instructors and facilitators of learning can no longer rely solely on traditional lecture-based lesson formals. In order to achieve student academic success and satisfaction and to increase student retention, instructors must embrace various technology tools that are available and employ them in their lessons. A longitudinal study (January 2009-June 2010) has been performed that encompasses the use of several technology tools in an instructional setting. The study provides further evidence that students not only like the tools that are being used, but prefer that these tools be used to help supplement and enhance instruction.

  5. Digital Longitudinal Tomography Using Backprojection.

    Science.gov (United States)

    Kampp, Thomas Dalton

    1987-09-01

    Conventional tomography allows a single section to be demonstrated on film with a single sweep of an x -ray tube. Each sweep of the x-ray tube exposes the patient to approximately one rad of radiation dose. This tomographic method has been extended by using a backprojection method to allow six degrees of freedom in the selection of the plane to be synthesized. As many planes as desired can be retrospectively tomosynthesized from a single sweep of the apparatus. This can greatly reduce the dose to the patient as well as eliminate patient motion artifacts that would occur with individually acquired slices using the traditional analogue film method. A linear tomographic table was modified by the addition of a digital imaging chain so that a set of projection images could be acquired with each sweep of the apparatus. The digital images were manipulated by a computer to tomosynthesize retrospectively any desired plane. This advanced tomographic system would complement CT which cannot yet match the resolution of this system for longitudinal studies. Various special phantoms were imaged in order to provide data which were used to determine the operating characteristics of this particular system. The characteristics measured are the system gray level response, sampling density, modulation transfer function, small area contrast, detection limits, signal-to-noise ratio, noise Wiener spectrum, and slice thickness. This laboratory piece of equipment could significantly detect approximately 1.7% contrast with a 1 mm pixel size. The MTF values and limiting resolution were approximately one -third of what can be obtained with current CT scanners. The system performed precisely as the computer simulations indicated. The dynamic range of the display is less than that of the image. Windowing of the final image can increase displayed contrast up to the limits imposed by noise. This is an improvement compared to film. With current state -of-the-art equipment, a little engineering and

  6. Longitudinal Trajectories of Cigarette Smoking Following Rape

    OpenAIRE

    Ananda B. Amstadter; Resnick, Heidi S.; Nugent, Nicole R.; Acierno, Ron; Rheingold, Alyssa A.; Minhinnett, Robin; Kilpatrick, Dean G.

    2009-01-01

    Although prior research has identified increases in cigarette smoking following trauma exposure, no studies have examined longitudinal trajectories of smoking following rape. The present investigation identifies and characterizes longitudinal ( 6 months post-assault) trajectories of smoking (N = 152) following a rape in a sample of 268 sexual assault victims participating in a forensic medical exam. Further, we examine acute predictors of subsequent smoking trajec...

  7. Marital assortment and phenotypic convergence: longitudinal evidence.

    Science.gov (United States)

    Caspi, A; Herbener, E S

    1993-01-01

    This study provides a direct test of whether the observed similarity of spouses is due to initial assortment rather than to convergence of phenotypes. With data from three well-known longitudinal studies, phenotypic convergence is examined using both variable- and person-centered analyses. The longitudinal evidence does not support the hypothesis that couples increasingly resemble each other with time. Spouse correlations most likely reflect initial assortment at marriage and not the convergence of phenotypes.

  8. Clinical and polysomnographic predictors of the Natural History of poor sleep in the general population

    OpenAIRE

    Fernandez-Mendoza, Julio; Vgontzas, Alexandros N.; Bixler, Edward O.; Singareddy, Ravi; Shaffer, Michele L.; Calhoun, Susan L.; KARATARAKI, MARIA; Vela-Bueno, Antonio; Liao, Duanping

    2012-01-01

    Study Objectives: Approximately 8-10% of the general population suffers from chronic insomnia, whereas another 20-30% of the population has insomnia symptoms at any given time (i.e., poor sleep). However, few longitudinal studies have examined risk factors of the natural history of poor sleep, and none have examined the role of polysomnographic (PSG) variables. Design: Representative longitudinal study. Setting: Sleep laboratory. Participants: From a random, general population ...

  9. Longitudinal investigation into genetics in the conservation of metabolic phenotypes in Danish and Chinese twins

    DEFF Research Database (Denmark)

    Li, Shuxia; Kyvik, Kirsten Ohm; Duan, Haiping;

    2016-01-01

    Longitudinal twin studies on long term conservation of individual metabolic phenotypes can help to explore the genetic and environmental basis in maintaining metabolic homeostasis and metabolic health. We performed a longitudinal twin study on 12 metabolic phenotypes from Danish twins followed up...... for 12 years and Chinese twins traced for 7 years. The study covered a relatively large sample of 502 pairs of Danish adult twins with a mean age at intake of 38 years and a total of 181 Chinese adult twin pairs with a mean baseline age of 39.5 years. Bivariate twin models were fitted to the longitudinal...... twin study on long-term stability of metabolic phenotypes in Danish and Chinese twins identified a common pattern of high genetic control over phenotype conservation, and at the same time revealed population-specific patterns of genetic and common environmental regulation on the variance as well...

  10. Longitudinal trajectories of aberrant behavior in fragile X syndrome.

    Science.gov (United States)

    Hustyi, Kristin M; Hall, Scott S; Jo, Booil; Lightbody, Amy A; Reiss, Allan L

    2014-11-01

    The Aberrant Behavior Checklist-Community (ABC-C; Aman et al., 1995) has been increasingly adopted as a primary tool for measuring behavioral change in clinical trials for individuals with fragile X syndrome (FXS). To our knowledge, however, no study has documented the longitudinal trajectory of aberrant behaviors in individuals with FXS using the ABC-C. As part of a larger longitudinal study, we examined scores obtained on the ABC-C subscales for 124 children and adolescents (64 males, 60 females) with FXS who had two or more assessments (average interval between assessments was approximately 4 years). Concomitant changes in age-equivalent scores on the Vineland Adaptive Behavior Scales (VABS) were also examined. As expected for an X-linked genetic disorder, males with FXS obtained significantly higher scores on all subscales of the ABC-C and significantly lower age-equivalent scores on the VABS than females with FXS. In both males and females with FXS, scores on the Irritability/Agitation and Hyperactivity/Noncompliance subscales of the ABC-C decreased significantly with age, with little to no change occurring over time on the Lethargy/Social Withdrawal, Stereotypic Behavior, and Inappropriate Speech subscales. The decrease in scores on the Hyperactivity/Noncompliance domain was significantly greater for males than for females. In both males and females, age-equivalent scores on the VABS increased significantly over this developmental period. These results establish a basis upon which to evaluate long-term outcomes from intervention-based research. However, longitudinal direct observational studies are needed to establish whether the severity of problem behavior actually decreases over time in this population.

  11. Joint multiple imputation for longitudinal outcomes and clinical events that truncate longitudinal follow-up.

    Science.gov (United States)

    Hu, Bo; Li, Liang; Greene, Tom

    2016-07-30

    Longitudinal cohort studies often collect both repeated measurements of longitudinal outcomes and times to clinical events whose occurrence precludes further longitudinal measurements. Although joint modeling of the clinical events and the longitudinal data can be used to provide valid statistical inference for target estimands in certain contexts, the application of joint models in medical literature is currently rather restricted because of the complexity of the joint models and the intensive computation involved. We propose a multiple imputation approach to jointly impute missing data of both the longitudinal and clinical event outcomes. With complete imputed datasets, analysts are then able to use simple and transparent statistical methods and standard statistical software to perform various analyses without dealing with the complications of missing data and joint modeling. We show that the proposed multiple imputation approach is flexible and easy to implement in practice. Numerical results are also provided to demonstrate its performance. Copyright © 2015 John Wiley & Sons, Ltd.

  12. Study of CSR longitudinal bunch compression cavity

    International Nuclear Information System (INIS)

    The scheme of longitudinal bunch compression cavity for the Cooling Storage Ring (CSR)is an important issue. Plasma physics experiments require high density heavy ion beam and short pulsed bunch,which can be produced by non-adiabatic compression of bunch implemented by a fast compression with 90 degree rotation in the longitudinal phase space. The phase space rotation in fast compression is initiated by a fast jump of the RF-voltage amplitude. For this purpose, the CSR longitudinal bunch compression cavity, loaded with FINEMET-FT-1M is studied and simulated with MAFIA code. In this paper, the CSR longitudinal bunch compression cavity is simulated and the initial bunch length of 238U72+ with 250 MeV/u will be compressed from 200 ns to 50 ns.The construction and RF properties of the CSR longitudinal bunch compression cavity are simulated and calculated also with MAFIA code. The operation frequency of the cavity is 1.15 MHz with peak voltage of 80 kV, and the cavity can be used to compress heavy ions in the CSR. (authors)

  13. Longitudinal surface structures (flowstripes on Antarctic glaciers

    Directory of Open Access Journals (Sweden)

    N. F. Glasser

    2011-11-01

    Full Text Available Longitudinal surface structures (''flowstripes'' are common on many glaciers but their origin and significance are poorly understood. In this paper we present observations of the development of these longitudinal structures from four different Antarctic glacier systems (the Lambert Glacier/Amery Ice Shelf area, outlet glaciers in the Ross Sea sector, ice-shelf tributary glaciers on the Antarctic Peninsula, and the onset zone of a tributary to the Recovery Glacier Ice Stream in the Filchner Ice Shelf area. Mapping from optical satellite images demonstrates that longitudinal surface structures develop in two main situations: (1 as relatively wide flow stripes within glacier flow units and (2 as relatively narrow flow stripes where there is convergent flow around nunataks or at glacier confluence zones. Our observations indicate that the confluence features are narrower, sharper, and more clearly defined features. They are characterised by linear troughs or depressions on the ice surface and are much more common than the former type. Longitudinal surface structures within glacier flow units have previously been explained as the surface expression of localised bed perturbations but a universal explanation for those forming at glacier confluences is lacking. Here we propose that these features are formed at zones of ice acceleration and extensional flow at glacier confluences. We provide a schematic model for the development of longitudinal surface structures based on extensional flow that can explain their ridge and trough morphology as well as their down-ice persistence.

  14. Longitudinal stability in multiharmonic standing wave linacs

    Science.gov (United States)

    Carver, L. R.; Jones, R. M.; Jiang, Y.; Hirshfield, J. L.

    2016-09-01

    Accelerating cavities that excite multiple modes at integer harmonics of the fundamental frequency have the potential to be used to suppress the onset of rf breakdown and reduce the pulsed surface heating at high accelerating gradients. Understanding the effect of an additional harmonic cavity mode on the longitudinal beam dynamics is important to their development and use. A Hamiltonian that describes the longitudinal motion of a particle as it traverses a chain of multiharmonic cavities has been derived and is applied to the case of a second harmonic cavity. The Hamiltonian is based upon formalisms found in literature for the fundamental harmonic and is extended to include different longitudinal field distributions and harmonic frequencies. The study initially explores the longitudinal motion for moderate accelerating gradients with high-β protons, as this will allow fundamental properties of the stable region (acceptance and shape of the rf bucket) to be determined. High accelerating gradients are also investigated but the focus will be on phase stability throughout. This work concludes by considering the longitudinal dynamics of a modified European Spallation Source accelerator, comprised of multiharmonic cavities that has specifications broadly consistent with the accelerator.

  15. Diet assessment in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil: Development of a food frequency questionnaire

    Directory of Open Access Journals (Sweden)

    Maria del Carmen Bisi Molina

    2013-04-01

    Full Text Available OBJECTIVE: The objective of this article is to present the development of the Food Frequency Questionaire used in the Longitudinal Study of Adult Health-Brazil and analyze how diet exposes individuals to cardiovascular diseases and type 2 diabetes Mellitus. METHODS: The Longitudinal Study of Adult Health-Brazil dietary assessment instrument is based on a previously validated Food Frequency Questionaire and the final list of items took into consideration a study done in the six Longitudinal Study of Adult Health-Brazil investigation centers. RESULTS: New foods/preparations were included in the Food Frequency Questionaire with their respective portions, totaling 114 items. The perspectives of dietary analysis and cardiovascular diseases and diabetes are presented in Longitudinal Study of Adult Health-Brazil. CONCLUSION: A new instrument was developed to cover the regional particularities of the study population.

  16. Longitudinal measurement invariance, stability and change of anger and cynicism.

    Science.gov (United States)

    Hakulinen, Christian; Jokela, Markus; Keltikangas-Järvinen, Liisa; Merjonen, Päivi; Raitakari, Olli T; Hintsanen, Mirka

    2014-06-01

    Anger and hostility are key concepts in behavioral medicine, but little is known about their stability over life course. A sample of 3,074 individuals from six age groups (aged 15-30 at the baseline) were selected from a population-based study to examine longitudinal measurement invariance, stability and change in anger and cynicism from early to middle adulthood over 15 years. Cynicism, a facet of hostility, and anger were measured 4 times in 1992, 1997, 2001 and 2007. Final longitudinal measurement invariance models achieved partial strict measurement invariance, indicating good measurement consistency over time. Rank-order stability of anger and cynicism was found to be moderate. Mean levels of anger and cynicism decreased over time, but in anger the decline was faster among women. The variance of anger and cynicism also increased over time, but in cynicism the rate of change was higher among men. Altogether, anger and cynicism show measurement invariance and moderate stability from early adulthood to middle adulthood.

  17. Promoting Population

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    THE world's population reached 5 billion in 1987,then 6 billion in 1999;now,in 2011,it is 7 billion.For a country with a set birth control policy,the way in which Chinese people and the media view this number has greatly changed.People are increasingly reflecting on the concept of population from a more scientific and rational perspective.This shift is a change from how people perceived population in the past.

  18. Longitudinal stent deformation during coronary bifurcation stenting.

    Science.gov (United States)

    Vijayvergiya, Rajesh; Sharma, Prafull; Gupta, Ankush; Goyal, Praveg; Panda, Prashant

    2016-03-01

    A distortion of implanted coronary stent along its longitudinal axis during coronary intervention is known as longitudinal stent deformation (LSD). LSD is frequently seen with newer drug eluting stents (DES), specifically with PROMUS Element stent. It is usually caused by impact of guide catheter tip, or following passage of catheters like balloon catheter, IVUS catheter, guideliner, etc. We hereby report a case of LSD during coronary bifurcation lesion intervention, using two-stents technique. Patient had acute stent thrombosis as a complication of LSD, which was successfully managed. PMID:26811144

  19. Longitudinal tibial epiphyseal bracket in Nievergelt syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Burnstein, M.I.; De Smet, A.A.; Breed, A.L.; Thomas, J.R.; Hafez, G.R.

    1989-04-01

    A patient is described with lower extremity mesomelic dwarfism associated with bilateral congenital elbow, hip, and knee dislocations. Rhomboid-shaped tibiae and delayed ossification of the primary fibular ossification centers were demonstrated at birth. Plain films and magnetic resonance imaging revealed that the tibial deformities were due to the presence of longitudinal epiphyseal brackets. These brackets were observed at surgery and confirmed histologically. Recognition of the longitudinal epiphyseal bracket and its relationship to the tibial deformities seen in this patient with Nievergelt syndrome is important for planning surgical treatment. (orig.).

  20. Longitudinal coupling effect in microfiber Bragg gratings

    Science.gov (United States)

    Zhao, Ping; Zhang, Jihua; Wang, Guanghui; Jiang, Meng; Ping Shum, Perry; Zhang, Xinliang

    2012-10-01

    We theoretically present longitudinal coupling effect (LCE) in air-cladding microfiber Bragg gratings (MFBGs). Distinct from conventional weakly-guiding optical fibers, large longitudinal electric field (Ez) exists in wavelength-scale microfibers. Due to LCE, MFBG reflectivity can be reduced by more than 30% within the band-gap and the full width at half maximum (FWHM) is obviously narrowed. This theoretical analytical work is instructive to precisely design and fabricate MFBGs that are promising in the areas of optical sensing and nanophotonics.

  1. Cancer and autoimmunity: Harnessing longitudinal cohorts to probe the link.

    Science.gov (United States)

    Egiziano, Giordano; Bernatsky, Sasha; Shah, Ami A

    2016-02-01

    In many autoimmune rheumatic diseases, there is an increased risk of cancer compared to the general population. While reasons for this increased risk have not been elucidated, it has been hypothesized that the link between cancer and autoimmunity may be bidirectional. For instance, chronic inflammation and damage from the rheumatic disease or its therapies may trigger malignant transformation; conversely, antitumor immune responses targeting cancers may become cross-reactive resulting in autoimmunity. In rare rheumatic diseases, longitudinal observational studies can play a critical role in studying these complex relationships, thereby enabling investigators to quantify the extent of cancer risk, identify unique clinical phenotypes associated with cancer, investigate the biological link between these conditions, and define optimal strategies for screening and treatment of the underlying cancer. In this review, we discuss recent data on cancer in the rheumatic diseases and suggest a research agenda to address several gaps in our current knowledge base. PMID:27421216

  2. Development of a longitudinal database for an integrated curriculum

    Directory of Open Access Journals (Sweden)

    Linda R. Adkison

    2014-09-01

    Full Text Available Many medical schools have transitioned to an integrated curriculum to provide a more salient contextual appreciation of the practice of medicine. Various types of assessments are used in these curricula to support this integration. One of these, multidisciplinary exams, creates challenges for recognizing student performance in different disciplines. A concern for faculty is those students who pass the exams but upon closer scrutiny do poorly in one or more disciplines. Unfortunately, this trend can continue throughout preclinical training. We constructed a database of discipline-specific objective data for each course and that also provided cumulative data longitudinally through the curriculum. The data are used to populate reports for the students, advisors, and administrators. The database was broadened to include data from clerkship performance and residency match to provide a complete profile of student performance. Together, the data and reports provide a useful tool for student review and data-driven curriculum decisions.

  3. Population Blocks.

    Science.gov (United States)

    Smith, Martin H.

    1992-01-01

    Describes an educational game called "Population Blocks" that is designed to illustrate the concept of exponential growth of the human population and some potential effects of overpopulation. The game material consists of wooden blocks; 18 blocks are painted green (representing land), 7 are painted blue (representing water); and the remaining…

  4. Distraction osteogenesis using a longitudinal corticotomy

    OpenAIRE

    AL-SAATI, Ma'ad F.; Magnussen, Robert A; LUSTIG, Sebastien; Testa, Rodolphe; Al-Saati, Gazal; Al-Saati, Faisal

    2011-01-01

    The purpose of this study was to evaluate whether the use of a longitudinal corticotomy (S-Z osteotomy) results in more rapid consolidation following distraction osteogenesis of short tibiae. Sixty-seven lengthening procedures were performed in 51 patients ranging in age from nine to 38 (mean 25) years.

  5. Kinetic theory of a longitudinally expanding system

    Directory of Open Access Journals (Sweden)

    Gelis François

    2016-01-01

    Full Text Available We use kinetic theory in order to study the role of quantum fluctuations in the isotropization of the pressure tensor in a system subject to fast longitudinal expansion, such as the matter produced in the early stages of a heavy ion collision.

  6. An electromagnetic shashlik calorimeter with longitudinal segmentation

    CERN Document Server

    Benvenuti, Alberto C; Camporesi, T; Checchia, P; Fenyuk, A; Hedberg, V; Lishin, V A; Margoni, M; Mazzucato, M; Obraztsov, V F; Paganoni, M; Polyakov, V A; Simonetto, F; Terranova, F; Vlasov, E

    1999-01-01

    A novel technique for longitudinal segmentation of shashlik calorimeters has been tested in the CERN West Area beam facility. A 25 tower e.m. calorimeter has been built with vacuum photodiodes inserted in the first 8 radiation lengths to sample the initial development of the shower. Results concerning energy resolution, impact point reconstruction and $e/\\pi$ separation are reported.

  7. Kinetic theory of a longitudinally expanding system

    CERN Document Server

    Gelis, Francois

    2016-01-01

    We use kinetic theory in order to study the role of quantum fluctuations in the isotropization of the pressure tensor in a system subject to fast longitudinal expansion, such as the matter produced in the early stages of a heavy ion collision.

  8. Teaching Technology Longitudinally to Virtual Children

    Science.gov (United States)

    Matthews, Lynley

    2010-01-01

    Children of Generation Y are entering our schooling system. These children have always known instant communication and the internet. They possess basic skills in using technology, but they still need to develop a deeper understanding of technology. Teaching longitudinally will increase the learner's confidence and develop a deeper understanding.…

  9. Investigating Ceiling Effects in Longitudinal Data Analysis

    Science.gov (United States)

    Wang, Lijuan; Zhang, Zhiyong; McArdle, John J.; Salthouse, Timothy A.

    2008-01-01

    Score limitation at the top of a scale is commonly termed "ceiling effect." Ceiling effects can lead to serious artifactual parameter estimates in most data analysis. This study examines the consequences of ceiling effects in longitudinal data analysis and investigates several methods of dealing with ceiling effects through Monte Carlo simulations…

  10. [Posterior longitudinal ligament ossification: case report].

    Science.gov (United States)

    Tella, Oswaldo Inácio de; Herculano, Marco Antonio; Paiva Neto, Manoel Antonio; Faedo Neto, Atílio; Crosera, João Francisco

    2006-03-01

    Posterior longitudinal ligament ossification of cervical spine is a rare condition among caucasians. A 42 years old japanese patient with progressive walking difficulty was diagnosed with this pathology by CT scan and MRI and treated surgically by an anterior approach with arthrodesis. Pathophysiology, racial prevalence, clinical picture, radiological characteristics and surgical approaches options are revised.

  11. Burnout development among dentists: a longitudinal study

    NARCIS (Netherlands)

    H. te Brake; N. Smits; J.M. Wicherts; R.C. Gorter; J. Hoogstraten

    2008-01-01

    Knowledge on the development of burnout among dentists is important for purposes of prevention and intervention. Using a two-wave longitudinal design, this study examined the chronological sequence of the three dimensions of the Maslach Burnout Inventory: emotional exhaustion; depersonalization; and

  12. Longitudinal bulk a coustic mass sensor

    DEFF Research Database (Denmark)

    Hales, Jan Harry; Teva, Jordi; Boisen, Anja;

    2009-01-01

    Design, fabrication and characterization, in terms of mass sensitivity, is presented for a polycrystalline silicon longitudinal bulk acoustic cantilever. The device is operated in air at 51 MHz, resulting in a mass sensitivity of 100 HZ/fg (1 fg = 10{su−15 g). The initial characterization...

  13. Longitudinal MRI studies of brain morphometry

    DEFF Research Database (Denmark)

    Skimminge, Arnold Jesper Møller

    , putamen, inferior and superior longitudinal fasciculus, corpus callosum and corona radiata. This indicates that the long-term atrophy is attributable to consequences of traumatic axonal injury. Despite progressive atrophy, remarkable clinical improvement occurred in most patients. The other study utilized...

  14. Modeling local dependence in longitudinal IRT models

    DEFF Research Database (Denmark)

    Olsbjerg, Maja; Christensen, Karl Bang

    2015-01-01

    variable. Ignoring this can lead to biased estimates of changes in the latent variable. In this paper we propose a method for modeling local dependence in the longitudinal 2PL model. It is based on the concept of item splitting, and makes it possible to correctly estimate change in the latent variable....

  15. Imaginary populations

    Directory of Open Access Journals (Sweden)

    A. Martínez–Abraín

    2010-01-01

    Full Text Available A few years ago, Camus & Lima (2002 wrote an essay to stimulate ecologists to think about how we define and use a fundamental concept in ecology: the population. They concluded, concurring with Berryman (2002, that a population is "a group of individuals of the same species that live together in an area of sufficient size to permit normal dispersal and/or migration behaviour and in which population changes are largely the results of birth and death processes". They pointed out that ecologists often forget "to acknowledge that many study units are neither natural nor even units in terms of constituting a population system", and hence claimed that we "require much more accuracy than in past decades in order to be more effective to characterize populations and predict their behaviour". They stated that this is especially necessary "in disciplines such as conservation biology or resource pest management, to avoid reaching wrong conclusions or making inappropriate decisions". As a population ecologist and conservation biologist I totally agree with these authors and, like them, I be¬lieve that greater precision and care is needed in the use and definition of ecological terms. The point I wish to stress here is that we ecologists tend to forget that when we use statistical tools to infer results from our sample to a population we work with what statisticians term "imaginary", "hypothetical" or "potential" popula¬tions. As Zar (1999 states, if our sample data consist of 40 measurements of growth rate in guinea pigs "the population about which conclusions might be drawn is the growth rates of all the guinea pigs that conceivably might have been administered the same food supplement under identical conditions". Such a population does not really exist, and hence it is considered a hypothetical or imaginary population. Compare that definition with the population concept that would be in our minds when performing such measurements. We would probably

  16. Prenatal stress and risk of febrile seizures in children: a nationwide longitudinal study in Denmark

    DEFF Research Database (Denmark)

    Li, Jiong; Olsen, Jørn; Obel, Carsten;

    2009-01-01

    We aimed to examine whether exposure to prenatal stress following maternal bereavement is associated with an increased risk of febrile seizures. In a longitudinal population-based cohort study, we followed 1,431,175 children born in Denmark. A total of 34,777 children were born to women who lost a...... timing of bereavement. Our data do not suggest any causal link between exposure to prenatal stress and febrile seizures in childhood....

  17. Body Image Distortions, Weight, and Depression in Adolescent Boys: Longitudinal Trajectories into Adulthood

    OpenAIRE

    Blashill, Aaron J.; Wilhelm, Sabine

    2013-01-01

    Depressive symptoms are common among the U.S. population, yet research into prospective risk factors of depression among men is limited. Distorted body image is also prevalent among adolescent boys, and may be linked with elevated depression; however, longitudinal associations have rarely been measured. Thus, the aim of the current study was to assess the prospective relationship between forms of body image distortion and depressive symptoms among adolescent boys, into adulthood. Data were ex...

  18. Effect of Helicobacter pylori infection on growth trajectories in young Ethiopian children: a longitudinal study

    OpenAIRE

    Bineyam Taye; Fikre Enquselassie; Aster Tsegaye; Alemayehu Amberbir; Girmay Medhin; Andrew Fogarty; Karen Robinson; Gail Davey

    2016-01-01

    Background: Helicobacter pylori infection has been associated with early childhood growth impairment in high- and middle-income countries; however, few studies have examined this relationship within low-income countries or have used a longitudinal design. The possible effects of H. pylori infection on growth trajectories were examined in a cohort of young Ethiopian children. Methods: In 2011/12, 856 children (85.1% of the 1006 original singletons in a population-based birth cohort) were fo...

  19. Population policy.

    Science.gov (United States)

    1987-03-01

    Participants in the Seminar on Population Policies for Top-level Policy Makers and Program Managers, meeting in Thailand during January 1987, examined the challenges now facing them regarding the implementation of fertility regulation programs in their respective countries -- Bangladesh, China, India, Indonesia, Malaysia, Nepal, Pakistan, the Philippines, the Republic of Korea, and Thailand. This Seminar was organized to coincide with the completion of an Economic and Social Commission for Asia and the Pacific (ESCAP) study investigating the impact and efficiency of family planning programs in the region. Country studies were reviewed at the Seminar along with policy issues about the status of women, incentive and disincentive programs, and socioeconomic factors affecting fertility. In Bangladesh the government recognizes population growth as its top priority problem related to the socioeconomic development of the country and is working to promote a reorientation strategy from the previous clinic-oriented to a multidimensional family welfare program. China's family planning program seeks to postpone marraige, space the births of children between 3-5 years, and promote the 1-child family. Its goal is to reduce the rate of natural increase from 12/1000 in 1978 to 5/1000 by 1985 and 0 by 2000. India's 7th Five-Year-Plan (1986-90) calls for establishing a 2-child family norm by 2000. In Indonesia the government's population policy includes reducing the rate of population growth, achieving a redistribution of the population, adjusting economic factors, and creating prosperous families. The government of Indonesia reversed its policy to reduce the population growth rate in 1984 and announced its goal of achieving a population of 70 million by 2100 in order to support mass consumption industries. It has created an income tax deduction system favoring large families and maternity benefits for women who have up to 5 children as incentives. Nepal's official policy is to

  20. Population policy.

    Science.gov (United States)

    1987-03-01

    Participants in the Seminar on Population Policies for Top-level Policy Makers and Program Managers, meeting in Thailand during January 1987, examined the challenges now facing them regarding the implementation of fertility regulation programs in their respective countries -- Bangladesh, China, India, Indonesia, Malaysia, Nepal, Pakistan, the Philippines, the Republic of Korea, and Thailand. This Seminar was organized to coincide with the completion of an Economic and Social Commission for Asia and the Pacific (ESCAP) study investigating the impact and efficiency of family planning programs in the region. Country studies were reviewed at the Seminar along with policy issues about the status of women, incentive and disincentive programs, and socioeconomic factors affecting fertility. In Bangladesh the government recognizes population growth as its top priority problem related to the socioeconomic development of the country and is working to promote a reorientation strategy from the previous clinic-oriented to a multidimensional family welfare program. China's family planning program seeks to postpone marraige, space the births of children between 3-5 years, and promote the 1-child family. Its goal is to reduce the rate of natural increase from 12/1000 in 1978 to 5/1000 by 1985 and 0 by 2000. India's 7th Five-Year-Plan (1986-90) calls for establishing a 2-child family norm by 2000. In Indonesia the government's population policy includes reducing the rate of population growth, achieving a redistribution of the population, adjusting economic factors, and creating prosperous families. The government of Indonesia reversed its policy to reduce the population growth rate in 1984 and announced its goal of achieving a population of 70 million by 2100 in order to support mass consumption industries. It has created an income tax deduction system favoring large families and maternity benefits for women who have up to 5 children as incentives. Nepal's official policy is to

  1. Population neuroscience.

    Science.gov (United States)

    Paus, T

    2016-01-01

    Population neuroscience endeavors to identify influences shaping the human brain from conception onwards, thus generating knowledge relevant for building and maintaining brain health throughout the life span. This can be achieved by studying large samples of participants drawn from the general population and evaluated with state-of-the-art tools for assessing (a) genes and their regulation; (b) external and internal environments; and (c) brain properties. This chapter reviews the three elements of population neuroscience (principles, tools, innovations, limitations), and discusses future directions in this field. PMID:27637950

  2. Time-varying effect modeling with longitudinal data truncated by death: conditional models, interpretations, and inference.

    Science.gov (United States)

    Estes, Jason P; Nguyen, Danh V; Dalrymple, Lorien S; Mu, Yi; Şentürk, Damla

    2016-05-20

    Recent studies found that infection-related hospitalization was associated with increased risk of cardiovascular (CV) events, such as myocardial infarction and stroke in the dialysis population. In this work, we develop time-varying effects modeling tools in order to examine the CV outcome risk trajectories during the time periods before and after an initial infection-related hospitalization. For this, we propose partly conditional and fully conditional partially linear generalized varying coefficient models (PL-GVCMs) for modeling time-varying effects in longitudinal data with substantial follow-up truncation by death. Unconditional models that implicitly target an immortal population is not a relevant target of inference in applications involving a population with high mortality, like the dialysis population. A partly conditional model characterizes the outcome trajectory for the dynamic cohort of survivors, where each point in the longitudinal trajectory represents a snapshot of the population relationships among subjects who are alive at that time point. In contrast, a fully conditional approach models the time-varying effects of the population stratified by the actual time of death, where the mean response characterizes individual trends in each cohort stratum. We compare and contrast partly and fully conditional PL-GVCMs in our aforementioned application using hospitalization data from the United States Renal Data System. For inference, we develop generalized likelihood ratio tests. Simulation studies examine the efficacy of estimation and inference procedures. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26646582

  3. Population dynamics

    Directory of Open Access Journals (Sweden)

    Cooch, E. G.

    2004-06-01

    Full Text Available Increases or decreases in the size of populations over space and time are, arguably, the motivation for much of pure and applied ecological research. The fundamental model for the dynamics of any population is straightforward: the net change over time in the abundance of some population is the simple difference between the number of additions (individuals entering the population minus the number of subtractions (individuals leaving the population. Of course, the precise nature of the pattern and process of these additions and subtractions is often complex, and population biology is often replete with fairly dense mathematical representations of both processes. While there is no doubt that analysis of such abstract descriptions of populations has been of considerable value in advancing our, there has often existed a palpable discomfort when the ‘beautiful math’ is faced with the often ‘ugly realities’ of empirical data. In some cases, this attempted merger is abandoned altogether, because of the paucity of ‘good empirical data’ with which the theoretician can modify and evaluate more conceptually–based models. In some cases, the lack of ‘data’ is more accurately represented as a lack of robust estimates of one or more parameters. It is in this arena that methods developed to analyze multiple encounter data from individually marked organisms has seen perhaps the greatest advances. These methods have rapidly evolved to facilitate not only estimation of one or more vital rates, critical to population modeling and analysis, but also to allow for direct estimation of both the dynamics of populations (e.g., Pradel, 1996, and factors influencing those dynamics (e.g., Nichols et al., 2000. The interconnections between the various vital rates, their estimation, and incorporation into models, was the general subject of our plenary presentation by Hal Caswell (Caswell & Fujiwara, 2004. Caswell notes that although interest has traditionally

  4. Longitudinal associations between descriptive and injunctive norms of youngsters and heavy drinking and problem drinking in late adolescence

    NARCIS (Netherlands)

    C.V. Voogt; H. Larsen; E.A.P. Poelen; M. Kleinjan; R.C.M.E. Engels

    2013-01-01

    Cross-sectionally, social norms are related to heavy and problem drinking in late adolescence. A better understanding is needed regarding the longitudinal associations between social norms in younger populations and heavy and problem drinking over time. This study distinguished between descriptive (

  5. Higher outdoor temperatures are progressively associated with lower blood pressure: a longitudinal study in 100,000 healthy individuals

    NARCIS (Netherlands)

    Hurk, K. van den; Kort, W.L. de; Deinum, J.; Atsma, F.

    2015-01-01

    This study investigated the shape of associations between climate parameters (mean daily temperature and humidity) and systolic and diastolic blood pressure in a large longitudinal cohort of healthy individuals. The study population comprised 101,377 Dutch whole blood and plasma donors (50% men), wh

  6. A Longitudinal Examination of the Psychoeducational, Neurocognitive, and Psychiatric Functioning in Children with 22q11.2 Deletion Syndrome

    Science.gov (United States)

    Hooper, Stephen R.; Curtiss, Kathleen; Schoch, Kelly; Keshavan, Matcheri S.; Allen, Andrew; Shashi, Vandana

    2013-01-01

    The present study sought to examine the longitudinal psychoeducational, neurocognitive, and psychiatric outcomes of children and adolescents with chromosome 22q11.2 deletion syndrome (22q11DS), a population with a high incidence of major psychiatric illnesses appearing in late adolescence/early adulthood. Little is known of the developmental…

  7. Early Indicators of Autism Spectrum Disorders at 12 and 24 Months of Age: A Prospective, Longitudinal Comparative Study

    Science.gov (United States)

    Veness, Carly; Prior, Margot; Bavin, Edith; Eadie, Patricia; Cini, Eileen; Reilly, Sheena

    2012-01-01

    Prospective questionnaire data from a longitudinal population sample on children with autism spectrum disorders (ASD), developmental delay, specific language impairment, or typical development (TD), were collected at ages eight, 12 and 24 months, via the Communication and Symbolic Behavior Scale Developmental Profile (CSBS)--Infant Toddler…

  8. Longitudinal Surveys of Australian Youth (LSAY): 1995 Cohort--User Guide. Data Elements A: Demographics. Technical Report 49A

    Science.gov (United States)

    National Centre for Vocational Education Research (NCVER), 2012

    2012-01-01

    This technical paper contains information about the variables in the LSAY (Longitudinal Surveys of Australian Youth) Y95 cohort data set. It groups each variable into data elements which identifies common variables within and across waves. Information is provided about each data element including its purpose, values, base populations and relevant…

  9. Avoiding asymmetry-induced bias in longitudinal image processing

    OpenAIRE

    Reuter, Martin; Fischl, Bruce

    2011-01-01

    Longitudinal image processing procedures frequently transfer or pool information across time within subject, with the dual goals of reducing the variability and increasing the accuracy of the derived measures. In this note, we discuss common difficulties in longitudinal image processing, focusing on the introduction of bias, and describe the approaches we have taken to avoid them in the FreeSurfer longitudinal processing stream.

  10. A longitudinal examination of maternal, family, and area-level experiences of racism on children's socioemotional development: Patterns and possible explanations

    OpenAIRE

    Becares, Laia; Nazroo, James; Kelly, Yvonne

    2015-01-01

    The association between experienced racial discrimination and poor health is now well documented, particularly among adult populations. However, longitudinal studies of the association between racism and child health are limited, and evidence on how racial discrimination experienced by members of children's immediate environment impact on child development, and the mechanisms by which this occurs, is scarce. We examined the longitudinal association between maternal, family, and area-level exp...

  11. Childhood interleukin-6, C-reactive protein and atopic disorders as risk factors for hypomanic symptoms in young adulthood: a longitudinal birth cohort study

    OpenAIRE

    Hayes, J. F.; Khandaker, G. M.; Anderson, J.; Mackay, D.; Zammit, S.; Lewis, G; Smith, D J; Osborn, D. P. J.

    2016-01-01

    Background: There are no existing longitudinal studies of inflammatory markers and atopic disorders in childhood and risk of hypomanic symptoms in adulthood. This study examined if childhood: (1) serum interleukin-6 (IL-6) and C-reactive protein (CRP); and (2) asthma and/or eczema are associated with features of hypomania in young adulthood. Method: Participants in the Avon Longitudinal Study of Parents and Children, a prospective general population UK birth cohort, had non-fasting blood s...

  12. Predicting time to prostate cancer recurrence based on joint models for non-linear longitudinal biomarkers and event time outcomes.

    Science.gov (United States)

    Pauler, Donna K; Finkelstein, Dianne M

    2002-12-30

    Biological markers that are both sensitive and specific for tumour regrowth or metastasis are increasingly becoming available and routinely monitored during the regular follow-up of patients treated for cancer. Obtained by a simple blood test, these markers provide an inexpensive non-invasive means for the early detection of recurrence (or progression). Currently, the longitudinal behaviour of the marker is viewed as an indicator of early disease progression, and is applied by a physician in making clinical decisions. One marker that has been studied for use in both population screening for early disease and for detection of recurrence in prostate cancer patients is PSA. The elevation of PSA levels is known to precede clinically detectable recurrence by 2 to 5 years, and current clinical practice often relies partially on multiple recent rises in PSA to trigger a change in treatment. However, the longitudinal trajectory for individual markers is often non-linear; in many cases there is a decline immediately following radiation therapy or surgery, a plateau during remission, followed by an exponential rise following the recurrence of the cancer. The aim of this article is to determine the multiple aspects of the longitudinal PSA biomarker trajectory that can be most sensitive for predicting time to clinical recurrence. Joint Bayesian models for the longitudinal measures and event times are utilized based on non-linear hierarchical models, implied by unknown change-points, for the longitudinal trajectories, and a Cox proportional hazard model for progression times, with functionals of the longitudinal parameters as covariates in the Cox model. Using Markov chain Monte Carlo sampling schemes, the joint model is fit to longitudinal PSA measures from 676 patients treated at Massachusetts General Hospital between the years 1988 and 1995 with follow-up to 1999. Based on these data, predictive schemes for detecting cancer recurrence in new patients based on their

  13. Stellar Populations

    Science.gov (United States)

    Peletier, Reynier F.

    2013-10-01

    This is a summary of my lectures during the 2011 Canary Islands Winter School in Puerto de la Cruz. I give an introduction to the field of stellar populations in galaxies, and highlight some new results. Since the title of the Winter School is Secular Evolution in Galaxies I mostly concentrate on nearby galaxies, which are best suited to study this theme. Of course, the understanding of stellar populations is intimately connected to understanding the formation and evolution of galaxies, one of the great outstanding problems of astronomy. We are currently in a situation where very large observational advances have been made in recent years. Galaxies have been detected up to a redshift of ten. A huge effort has to be made so that stellar population theory can catch up with observations. Since most galaxies are far away, information about them has to come from stellar population synthesis of integrated light. Here I will discuss how stellar evolution theory, together with observations in our Milky Way and Local Group, are used as building blocks to analyse these integrated stellar populations.

  14. Longitudinal spin dynamics in ferrimagnets: Multiple spin wave nature of longitudinal spin excitations

    Science.gov (United States)

    Krivoruchko, V. N.

    2016-08-01

    Motivated by the existing controversy about the physical mechanisms that govern longitudinal magnetization dynamics under the effect of ultrafast laser pulses, in this paper we study the microscopic model of longitudinal spin excitations in a two-sublattice ferrimagnet using the diagrammatic technique for spin operators. The diagrammatic approach provides us with an efficient procedure to derive graphical representations for perturbation expansion series for different spin Green's functions and thus to overcome limitations typical for phenomenological approaches. The infinite series involving all distinct loops built from spin wave propagators are summed up. These result in an expression for the longitudinal spin susceptibility χz z(q ,ω ) applicable in all regions of frequency ω and wave vector q space beyond the hydrodynamical and critical regimes. A strong renormalization of the longitudinal spin oscillations due to processes of virtual creation and annihilation of transverse spin waves has been found. We have shown that the spectrum of longitudinal excitations consists of a quasirelaxation mode forming a central peak in χz z(q ,ω ) and two (acoustic and exchange) precessionlike modes. As the main result, it is predicted that both acoustic and exchange longitudinal excitations are energetically above similar modes of transverse spin waves at the same temperature and wave vector. The existence of the exchange longitudinal mode at such frequencies can result in a new form of excitation behavior in ferrimagnetic system, which could be important for understanding the physics of nonequilibrium magnetic dynamics under the effect of ultrafast laser pulses in multisublattice magnetic materials.

  15. Diagnosis of longitudinally extensive transverse myelitis

    OpenAIRE

    Nightingale, Helen; Witherick, Jonathan; Wilkins, Alastair

    2011-01-01

    Longitudinally extensive transverse myelitis (LETM) is a neurological condition characterised by a contiguous inflammatory lesion of the spinal cord. LETM is often associated with the autoimmune central nervous system disease neuromyelitis optica (NMO) and rarely with multiple sclerosis. The discovery of the NMO-IgG antibody, provides a useful serological marker of LETM associated with the NMO disease spectrum (LETM and/or optic neuritis). Here, the authors report two cases of LETM, which dif...

  16. Longitudinal Laser Shaping in Laser Wakefield Accelerators

    OpenAIRE

    Spitkovsky, Anatoly; Chen, Pisin

    2000-01-01

    We study the energetics of wake excitation during the laser-plasma interaction in application to laser wakefield accelerators. We find that both the wake amplitude and the accelerating efficiency (transformer ratio) can be maximized by properly shaping the longitudinal profile of the driving laser pulse. The corresponding family of laser pulse shapes is derived in the nonlinear regime of laser-plasma interaction. Such shapes provide theoretical upper limit on the magnitude of the wakefield an...

  17. Marginal longitudinal semiparametric regression via penalized splines

    KAUST Repository

    Al Kadiri, M.

    2010-08-01

    We study the marginal longitudinal nonparametric regression problem and some of its semiparametric extensions. We point out that, while several elaborate proposals for efficient estimation have been proposed, a relative simple and straightforward one, based on penalized splines, has not. After describing our approach, we then explain how Gibbs sampling and the BUGS software can be used to achieve quick and effective implementation. Illustrations are provided for nonparametric regression and additive models.

  18. Marginal longitudinal semiparametric regression via penalized splines.

    Science.gov (United States)

    Kadiri, M Al; Carroll, R J; Wand, M P

    2010-08-01

    We study the marginal longitudinal nonparametric regression problem and some of its semiparametric extensions. We point out that, while several elaborate proposals for efficient estimation have been proposed, a relative simple and straightforward one, based on penalized splines, has not. After describing our approach, we then explain how Gibbs sampling and the BUGS software can be used to achieve quick and effective implementation. Illustrations are provided for nonparametric regression and additive models.

  19. Natural disasters and population mobility in Bangladesh

    OpenAIRE

    Gray, Clark L.; Mueller, Valerie

    2012-01-01

    The consequences of environmental change for human migration have gained increasing attention in the context of climate change and recent large-scale natural disasters, but as yet relatively few large-scale and quantitative studies have addressed this issue. We investigate the consequences of climate-related natural disasters for long-term population mobility in rural Bangladesh, a region particularly vulnerable to environmental change, using longitudinal survey data from 1,700 households spa...

  20. Feasibility and reference values of left atrial longitudinal strain imaging by two-dimensional speckle tracking

    Directory of Open Access Journals (Sweden)

    Lisi Matteo

    2009-02-01

    Full Text Available Abstract Background The role of speckle tracking in the assessment of left atrial (LA deformation dynamics is not established. We sought to determine the feasibility and reference ranges of LA longitudinal strain indices measured by speckle tracking in a population of normal subjects. Methods In 60 healthy individuals, peak atrial longitudinal strain (PALS and time to peak longitudinal strain (TPLS were measured using a 12-segment model for the left atrium. Values were obtained by averaging all segments (global PALS and TPLS and by separately averaging segments measured in the two apical views (4- and 2-chamber average PALS and TPLS. Results Adequate tracking quality was achieved in 97% of segments analyzed. Inter and intra-observer variability coefficients of measurements ranged between 2.9% and 5.4%. Global PALS was 42.2 ± 6.1% (5–95° percentile range 32.2–53.2%, and global TPLS was 368 ± 30 ms (5–95° percentile range 323–430 ms. The 2-chamber average PALS was slightly higher than the 4-chamber average PALS (44.3 ± 6.0% vs 40.1 ± 7.9%, p Conclusion Speckle tracking is a feasible technique for the assessment of longitudinal myocardial LA deformation. Reference ranges of strain indices were reported.

  1. Forbidden fruit? A longitudinal study of Christianity, sex, and marriage.

    Science.gov (United States)

    Pedersen, Willy

    2014-01-01

    Does religion still play a role in explorations of romance and sexuality among adolescents and young adults in a secular society such as Norway? Does it influence the type of living arrangements chosen? A population-based sample (n = 2,454) was followed longitudinally from their midteens to their late 20s using survey and register data. Christian involvement in teenage years was associated with subsequent less "precoital" exploration, less masturbation, delayed sexual intercourse, and a smaller number of sex partners. However, there were no associations with prevalence of same-sex experiences. Christians also postponed initiating romantic relationships and chose marriage over cohabitation. Associations were reduced after controlling for confounding factors but remained significant. Some associations (for example, the form of residential union chosen) were present only in the most "active" Christians. In other areas, such as "precoital explorations" and the age at which intercourse is initiated, Christian norms seem to play a role in much broader segments of the population. The findings indicate that Christianity may continue to influence young Norwegians' experiences of sexuality and cohabitation more than has been expected. PMID:23631689

  2. Multilevel Cross-Dependent Binary Longitudinal Data

    KAUST Repository

    Serban, Nicoleta

    2013-10-16

    We provide insights into new methodology for the analysis of multilevel binary data observed longitudinally, when the repeated longitudinal measurements are correlated. The proposed model is logistic functional regression conditioned on three latent processes describing the within- and between-variability, and describing the cross-dependence of the repeated longitudinal measurements. We estimate the model components without employing mixed-effects modeling but assuming an approximation to the logistic link function. The primary objectives of this article are to highlight the challenges in the estimation of the model components, to compare two approximations to the logistic regression function, linear and exponential, and to discuss their advantages and limitations. The linear approximation is computationally efficient whereas the exponential approximation applies for rare events functional data. Our methods are inspired by and applied to a scientific experiment on spectral backscatter from long range infrared light detection and ranging (LIDAR) data. The models are general and relevant to many new binary functional data sets, with or without dependence between repeated functional measurements.

  3. Longitudinal ligaments of the lumbar spine

    International Nuclear Information System (INIS)

    The diagnosis of disruption of the posterior longitudinal ligament in disk herniation is important in deciding between surgical or percutaneous management of HNP. The normal ligaments studied on spine specimens are better seen on long repetition time (TR), short echo time (TE) images and appear as linear structures with very low signal intensity on all pulse sequences surrounding the outer anulus. The authors prospectively imaged 20 HNPs in 18 patients who underwent surgery. In eight cases, the posterior longitudinal ligament was seen intact around the HNP on both short TR, short TE and long TR, short TE images. All were subligamentous at surgery. MR imaging demonstrated disruption of the longitudinal ligament in ten cases because of interruption, absence around the disk fragment, or interposition between disk and fragment. The ligament was disrupted at surgery in only eight of these cases. The two false-positive images showed a pseudointerruption related to a chemical shift antifact. The two remaining studies were qualified as questionable. The overall sensitivity of MR imaging was 100%, and its specificity was 77%

  4. Modeling HIF relevant longitudinal dynamics in UMER

    Energy Technology Data Exchange (ETDEWEB)

    Beaudoin, B.L., E-mail: beaudoin@umd.edu; Bernal, S.; Blanco, C.; Haber, I.; Kishek, R.A.; Koeth, T.; Mo, Y.

    2014-01-01

    The foremost challenge for Heavy-Ion Fusion (HIF) is achieving sufficiently low emittances and small energy spreads in the presence of intense space-charge, to achieve the high deposition densities necessary for pellet ignition. The University of Maryland Electron Ring (UMER) uses intense low-energy electron beams to access the scaled physics of HIF drivers. In particular, the long path-length propagation in UMER presents an opportunity to study, at realistic scales, the longitudinal beam dynamics and manipulations required for such a driver. With the use of induction modules, as in the ion machines such as NDCX-II, the resulting bunch dynamics show evidence of space-charge waves excited by an initial mismatch between the detailed initial beam distribution at the bunch ends and the applied focusing waveforms, persisting with multiple damped reflections propagating along the bunch flat-top. Using the induction module we are able to suppress space-charge waves with great accuracy, at amplitudes that include wave steepening prior to the formation of solitary wave trains. The longitudinal dynamics largely dominates when no containment fields are applied, coupling through the natural chromaticity of the ring even within the first turn. After subsequent turns, the bunch elongates and wraps the circumference of the machine multiple times; eventually reaching a point of instability that has also been shown through simulation, obtaining excellent agreement when the detailed longitudinal dynamics of the experiment are carefully incorporated into the model.

  5. Primary healthcare costs associated with sleep problems up to age 7 years: Australian population-based study

    OpenAIRE

    Quach, J; Gold, L; Hiscock, H; Mensah, F K; Lucas, N; Nicholson, J M; Wake, M.

    2013-01-01

    Objectives In Australian 0–7-year olds with and without sleep problems, to compare (1) type and costs to government of non-hospital healthcare services and prescription medication in each year of age and (2) the cumulative costs according to persistence of the sleep problem. Design Cross-sectional and longitudinal data from a longitudinal population study. Setting Data from two cohorts participating in the first two waves of the nationally representative Longitudinal Study of Australian Child...

  6. Stellar Populations

    NARCIS (Netherlands)

    Peletier, Reynier F.

    2013-01-01

    This is a summary of my lectures during the 2011 Canary Islands Winter School in Puerto de la Cruz. I give an introduction to the field of stellar populations in galaxies, and highlight some new results. Since the title of the Winter School is Secular Evolution in Galaxies I mostly concentrate on ne

  7. Population success.

    Science.gov (United States)

    1982-01-01

    "The commitment to population programs is now widespread," says Rafael Salas, Executive Director of the UNFPA, in its report "State of World Population." About 80% of the total population of the developing world live in countries which consider their fertility levels too high and would like them reduced. An important impetus came from the World Conference of 1974. The Plan of Action from the conference projected population growth rates in developing countries of 2.0% by 1985. Today it looks as though this projection will be realized. While in 1969, for example, only 26 developing countries had programs aimed at lowering or maintaining fertility levels, by 1980 there were 59. The International Population Conference, recently announced by the UN for 1984, will, it is hoped, help sustain that momentum. Cuba is the country which has shown the greatest decline in birth rate so far. The birth rate fell 47% between 1965-1970 and 1975-1980. Next came China with a 34% decline in the same period. After these came a group of countries--each with populations of over 10 million--with declines of between 15 and 25%: Chile, Colombia, India, Indonesia, the Republic of Korea, Malaysia and Thailand. Though birth rates have been dropping significantly the decline in mortality rates over recent years has been less than was hoped for. The 1974 conference set 74 years as the target for the world's average expectation of life, to be reached by the year 2000. But the UN now predicts that the developing countries will have only reached 63 or 64 years by then. High infant and child mortality rates, particularly in Africa, are among the major causes. The report identifies the status of women as an important determinant of family size. Evidence from the UNFPA-sponsored World Fertility Survey shows that in general the fertility of women decreases as their income increases. It also indicates that women who have been educated and who work outside the home are likely to have smaller families

  8. DROUGHT AND POPULATION MOBILITY IN RURAL ETHIOPIA.

    Science.gov (United States)

    Gray, Clark; Mueller, Valerie

    2012-01-01

    Significant attention has focused on the possibility that climate change will displace large populations in the developing world, but few multivariate studies have investigated climate-induced migration. We use event history methods and a unique longitudinal dataset from the rural Ethiopian highlands to investigate the effects of drought on population mobility over a ten-year period. The results indicate that men's labor migration increases with drought and that land-poor households are most vulnerable. However, marriage-related moves by women also decrease with drought. These findings suggest a hybrid narrative of environmentally-induced migration that recognizes multiple dimensions of adaptation to environmental change. PMID:22523447

  9. Population Aging

    OpenAIRE

    Weil, David N.

    2006-01-01

    Population aging is primarily the result of past declines in fertility, which produced a decades long period in which the ratio of dependents to working age adults was reduced. Rising old-age dependency in many countries represents the inevitable passing of this %u201Cdemographic dividend.%u201D Societies use three methods to transfer resources to people in dependent age groups: government, family, and personal saving. In developed countries, families are predominant in supporting children, w...

  10. An Exploratory Study of Socialization Effects on Black Children: Some Black-White Comparisons

    Science.gov (United States)

    Baumrind, Diana

    1972-01-01

    Major conclusion from this exploratory analysis was that if the black families were viewed by white norms they appeared authoritarian, but that, unlike their white counterparts, the most authoritarian of these families produced the most self-assertive and independent girls. (Author)

  11. MODELING BLACK-WHITE PRETERM BIRTH DISPARITY: ECOLOGIC AND MULTILEVEL MODELS

    Science.gov (United States)

    INTRODUCTION. The disparity between black and white women's adverse birth outcomes has been subject to much investigation, yet the factors underlying its persistence remain elusive, which has encouraged research on neighborhood-level influences. This work considers two main que...

  12. Black, white or green: 'race', gender and avatars within the therapeutic space.

    Science.gov (United States)

    Graber, Mark A; Graber, Abraham D

    2011-06-01

    Personal identity is critical to provider--patient interactions. Patients and doctors tend to self-select, ideally forming therapeutic units that maximise the patients' benefit. Recently, however, 'reality' has changed. The internet and virtual worlds such as Second Life (http://www.secondlife.com/) allow models of identity and provider--patient interactions that go beyond the limits of mainstream personal identity. In this paper some of the ethical implications of virtual patient--provider interactions, especially those that have to do with personal identity, are explored.

  13. American Innocence and Guilt: Black-White Destiny in Benito Cereno

    Science.gov (United States)

    Johnson, Paul David

    1975-01-01

    Asserts that the relationship between the Negro character and the white in American fiction before the Civil War reveals a social mythology which Herman Melville was the first to undercut, by presenting the destiny of Negroes linked to that of America as a symbol of nemesis to white Americans who disregard the impact of slavery on the enslavers…

  14. Labor Market Discrimination and Black-White Differences in Economic Status. Discussion Papers 403-77.

    Science.gov (United States)

    Garfinkel, Irwin; And Others

    Large disparities between blacks and whites in both earnings and income have persisted during the period since World War II. In this paper estimates are presented of the contribution of labor market discrimination to the earnings differential. Lower and upper bounds on this contribution are set. Also measured is the extent to which labor market…

  15. The black-white malleability gap in implicit racial evaluations: a nationally representative study.

    Science.gov (United States)

    Pinkston, Kevin

    2015-01-01

    This study replicates and extends the experimental design originated by Dasgupta and Greenwald (2001), who found a decrease in implicit pro-White biases after exposure to pictures of admired Black individuals. A nationally representative sample was analyzed comparing implicit pro-White biases among Black and White participants. Hypothesis 1 (H1) predicted a replication of previous research among White participants, and H2, derived from the balanced identity theory, predicted an increased pro-Black bias among Blacks after exposure to admired Black individuals. Results provided partial support for H1 and a lack of support for H2. This is the first study to use a nationally representative sample to examine implicit pro-White biases. System justification theory was used to explain the malleability gap in Black and White pro-racial biases. PMID:25492224

  16. Black/White Differences in Perceived Weight and Attractiveness among Overweight Women

    OpenAIRE

    Chithambo, Taona P.; Stanley J. Huey

    2013-01-01

    Numerous studies have reported that Black women are more satisfied with their bodies than White women. The buffering hypothesis suggests that aspects of Black culture protect Black women against media ideals that promote a slender female body type; therefore, Black women are expected to exhibit higher body esteem than White women. To test this hypothesis, the current study aimed to assess the influence of race on weight perception, perceived attractiveness, and the interrelations between body...

  17. The Impact of Neighborhood Disadvantage on the Black-White Achievement Gap

    Science.gov (United States)

    Lee, Moosung; Madyun, Na'im

    2009-01-01

    Contextual analysis of the achievement gap has gained much momentum within the last few decades. This study furthers the discourse by examining the applicability of 2 sociological contextual development approaches on achievement. We analyzed 79 neighborhoods organized by the level of crime and poverty from both a social disorganization and social…

  18. The Shrinking Black-White Gap on SAT II Achievement Tests.

    Science.gov (United States)

    Journal of Blacks in Higher Education, 2002

    2002-01-01

    Recent research shows that the SAT II test is a much better predictor of college success than the standard SAT. In recent years, black students appear to be making progress in closing the racial scoring gap on the wide variety of academic subjects (particularly chemistry, world history, and biology) that are measured by the SAT II test. (SM)

  19. A Black (White) Hole in the Global Spread of GM Cotton.

    Science.gov (United States)

    Burkitbayeva, Saule; Qaim, Matin; Swinnen, Johan

    2016-04-01

    Bt (Bacillus thuringiensis) cotton has been widely adopted, notably by smallholder farmers in developing countries. However, it has not been used in Central Asia, an important cotton-producing region. We discuss possible reasons and hypothesize that the most likely explanation is limited local demand for Bt owing to low levels of pest infestation. This would imply that global Bt cotton adoption rates may already be close to 100% when considering real demand for insect-resistant varieties. PMID:27017312

  20. A Black (White) Hole in the Global Spread of GM Cotton.

    Science.gov (United States)

    Burkitbayeva, Saule; Qaim, Matin; Swinnen, Johan

    2016-04-01

    Bt (Bacillus thuringiensis) cotton has been widely adopted, notably by smallholder farmers in developing countries. However, it has not been used in Central Asia, an important cotton-producing region. We discuss possible reasons and hypothesize that the most likely explanation is limited local demand for Bt owing to low levels of pest infestation. This would imply that global Bt cotton adoption rates may already be close to 100% when considering real demand for insect-resistant varieties.

  1. Equity Issues and Black-White Differences in Women's ERA Support.

    Science.gov (United States)

    Marshall, Susan E.

    1990-01-01

    Using data from 1982 National Opinion Research (NORC) General Social Survey, examines women's support for the Equal Rights Amendment (ERA) by analyzing attitudes about gender and racial equality, and socioeconomic status. Explains Black women's higher ERA approval as deriving from gender-role attitudes, but more important, from experience with,…

  2. Longitudinal evaluation of leukocyte transcripts in killer whales (Orcinus Orca).

    Science.gov (United States)

    Sitt, Tatjana; Bowen, Lizabeth; Lee, Chia-Shan; Blanchard, Myra T; McBain, James; Dold, Christopher; Stott, Jeffrey L

    2016-07-01

    Early identification of illness and/or presence of environmental and/or social stressors in free-ranging and domestic cetaceans is a priority for marine mammal health care professionals. Incorporation of leukocyte gene transcript analysis into the diagnostic tool kit has the potential to augment classical diagnostics based upon ease of sample storage and shipment, inducible nature and well-defined roles of transcription and associated downstream actions. Development of biomarkers that could serve to identify "insults" and potentially differentiate disease etiology would be of great diagnostic value. To this end, a modest number of peripheral blood leukocyte gene transcripts were selected for application to a domestic killer whale population with a focus on broad representation of inducible immunologically relevant genes. Normalized leukocyte transcript values, longitudinally acquired from 232 blood samples derived from 26 clinically healthy whales, were not visibly influenced temporally nor by sex or the specific Park in which they resided. Stability in leukocyte transcript number during periods of health enhances their potential use in diagnostics through identification of outliers. Transcript levels of two cytokine genes, IL-4 and IL-17, were highly variable within the group as compared to the other transcripts. IL-4 transcripts were typically absent. Analysis of transcript levels on the other genes of interest, on an individual animal basis, identified more outliers than were visible when analyzed in the context of the entire population. The majority of outliers (9 samples) were low, though elevated transcripts were identified for IL-17 from 2 animals and one each for Cox-2 and IL-10. The low number of outliers was not unexpected as sample selection was intentionally directed towards animals that were clinically healthy at the time of collection. Outliers may reflect animals experiencing subclinical disease that is transient and self-limiting. The immunologic

  3. Longitudinal evaluation of leukocyte transcripts in killer whales (Orcinus Orca)

    Science.gov (United States)

    Sitt, Tatjana; Bowen, Lizabeth; Lee, Chia-Shan; Blanchard, Myra; McBain, James; Dold, Christopher; Stott, Jeffrey L.

    2016-01-01

    Early identification of illness and/or presence of environmental and/or social stressors in free-ranging and domestic cetaceans is a priority for marine mammal health care professionals. Incorporation of leukocyte gene transcript analysis into the diagnostic tool kit has the potential to augment classical diagnostics based upon ease of sample storage and shipment, inducible nature and well-defined roles of transcription and associated downstream actions. Development of biomarkers that could serve to identify “insults” and potentially differentiate disease etiology would be of great diagnostic value. To this end, a modest number of peripheral blood leukocyte gene transcripts were selected for application to a domestic killer whale population with a focus on broad representation of inducible immunologically relevant genes. Normalized leukocyte transcript values, longitudinally acquired from 232 blood samples derived from 26 clinically healthy whales, were not visibly influenced temporally nor by sex or the specific Park in which they resided. Stability in leukocyte transcript number during periods of health enhances their potential use in diagnostics through identification of outliers. Transcript levels of two cytokine genes, IL-4 and IL-17, were highly variable within the group as compared to the other transcripts. IL-4 transcripts were typically absent. Analysis of transcript levels on the other genes of interest, on an individual animal basis, identified more outliers than were visible when analyzed in the context of the entire population. The majority of outliers (9 samples) were low, though elevated transcripts were identified for IL-17 from 2 animals and one each for Cox-2 and IL-10. The low number of outliers was not unexpected as sample selection was intentionally directed towards animals that were clinically healthy at the time of collection. Outliers may reflect animals experiencing subclinical disease that is transient and self-limiting. The

  4. Genetic and Environmental Regulation on Longitudinal Change of Metabolic Phenotypes in Danish and Chinese Adult Twins

    DEFF Research Database (Denmark)

    Li, Shuxia; Kyvik, Kirsten Ohm; Pang, Zengchang;

    2016-01-01

    OBJECTIVE: The rate of change in metabolic phenotypes can be highly indicative of metabolic disorders and disorder-related modifications. We analyzed data from longitudinal twin studies on multiple metabolic phenotypes in Danish and Chinese twins representing two populations of distinct ethnic...... pairs traced for about 7 years with a mean baseline age of 39.5 years (range: 23-64). The classical twin models were fitted to the longitudinal change in each phenotype (Δphenotype) to estimate the genetic and environmental contributions to the variation in Δphenotype. RESULTS: Moderate to high...... contributions by the unique environment were estimated for all phenotypes in both Danish (from 0.51 for low density lipoprotein cholesterol up to 0.72 for triglycerides) and Chinese (from 0.41 for triglycerides up to 0.73 for diastolic blood pressure) twins; low to moderate genetic components were estimated...

  5. Longitudinal Receptive American Sign Language Skills Across a Diverse Deaf Student Body.

    Science.gov (United States)

    Beal-Alvarez, Jennifer S

    2016-04-01

    This article presents results of a longitudinal study of receptive American Sign Language (ASL) skills for a large portion of the student body at a residential school for the deaf across four consecutive years. Scores were analyzed by age, gender, parental hearing status, years attending the residential school, and presence of a disability (i.e., deaf with a disability). Years 1 through 4 included the ASL Receptive Skills Test (ASL-RST); Years 2 through 4 also included the Receptive Test of ASL (RT-ASL). Student performance for both measures positively correlated with age; deaf students with deaf parents scored higher than their same-age peers with hearing parents in some instances but not others; and those with a documented disability tended to score lower than their peers without disabilities. These results provide longitudinal findings across a diverse segment of the deaf/hard of hearing residential school population. PMID:26864689

  6. Delineation of concentration ranges and longitudinal changes of human plasma protein variants.

    Directory of Open Access Journals (Sweden)

    Olgica Trenchevska

    Full Text Available Human protein diversity arises as a result of alternative splicing, single nucleotide polymorphisms (SNPs and posttranslational modifications. Because of these processes, each protein can exists as multiple variants in vivo. Tailored strategies are needed to study these protein variants and understand their role in health and disease. In this work we utilized quantitative mass spectrometric immunoassays to determine the protein variants concentration of beta-2-microglobulin, cystatin C, retinol binding protein, and transthyretin, in a population of 500 healthy individuals. Additionally, we determined the longitudinal concentration changes for the protein variants from four individuals over a 6 month period. Along with the native forms of the four proteins, 13 posttranslationally modified variants and 7 SNP-derived variants were detected and their concentration determined. Correlations of the variants concentration with geographical origin, gender, and age of the individuals were also examined. This work represents an important step toward building a catalog of protein variants concentrations and examining their longitudinal changes.

  7. IIB/M Duality and Longitudinal Membranes

    CERN Document Server

    Ho, P M; Ho, Pei-Ming; Wu, Yong-Shi

    1998-01-01

    In this paper we study duality properties of the M(atrix) theory compactified on a circle. We establish the equivalence of this theory to the strong coupling limit of type IIB string theory compactified on a circle. In the M(atrix) theory context, our major evidence for this duality consists of identifying the BPS states of IIB strings in the spectrum and finding the remnant symmetry of SL(2,Z) and the associated tau moduli. By this IIB/M duality, a number of insights are gained into the physics of longitudinal membranes in the infinite momentum frame. We also point out an accidental affine Lie symmetry in the theory.

  8. RHIC OPERATION WITH LONGITUDINALLY POLARIZED PROTONS.

    Energy Technology Data Exchange (ETDEWEB)

    HUANG,H.BAI,M.BEEBE-WANG,J.ET AL.

    2004-07-05

    Polarized proton beams have been accelerated, stored and collided at 100GeV per beam in the Relativistic Heavy Ion Collider (RHIC) with longitudinal polarization. The essential equipment includes four Siberian snakes, eight spin rotators and fast relative polarimeters in each of the two RHIC rings as well as local polarimeters at the STAR and PHENIX detectors. This paper summarizes the performance of RHIC as a polarized proton collider in the FY03 run with emphasis on polarization issues. Preliminary data from the FY04 run is also shown.

  9. Resonant longitudinal Zitterbewegung in zigzag graphene nanoribbons

    KAUST Repository

    Ghosh, S.

    2015-01-08

    The Zitterbewegung of a wave packet in a zigzag graphene nanoribbon is theoretically investigated. The coupling between edge states and bulk states results in intriguing properties. Apart from the oscillation in position perpendicular to the direction of motion, we also observe an oscillation along the direction of propagation which is not present in semiconductor nanowires or infinite graphene sheets. We also observe a resonance of its amplitude with respect to the central momentum of the wave packet. We show here that this longitudinal Zitterbewegung is caused by the interplay between bulk and edge states, which is a unique property of a zigzag nanoribbon.

  10. Children of Immigrants Longitudinal Study (CILS)

    OpenAIRE

    Rumbaut, RG; Portes, A.

    2006-01-01

    Children of Immigrants Longitudinal Study (CILS) was designed to study the adaptation process of the immigrant second generation which is defined broadly as United States-born children with at least one foreign-born parent or children born abroad but brought at an early age to the United States. The original survey was conducted with large samples of second-generation immigrant children attending the 8th and 9th grades in public and private schools in the metropolitan areas of Miami/Ft. Laude...

  11. Regional vulnerability of longitudinal cortical association connectivity

    Directory of Open Access Journals (Sweden)

    Rafael Ceschin

    2015-01-01

    Full Text Available Preterm born children with spastic diplegia type of cerebral palsy and white matter injury or periventricular leukomalacia (PVL, are known to have motor, visual and cognitive impairments. Most diffusion tensor imaging (DTI studies performed in this group have demonstrated widespread abnormalities using averaged deterministic tractography and voxel-based DTI measurements. Little is known about structural network correlates of white matter topography and reorganization in preterm cerebral palsy, despite the availability of new therapies and the need for brain imaging biomarkers. Here, we combined novel post-processing methodology of probabilistic tractography data in this preterm cohort to improve spatial and regional delineation of longitudinal cortical association tract abnormalities using an along-tract approach, and compared these data to structural DTI cortical network topology analysis. DTI images were acquired on 16 preterm children with cerebral palsy (mean age 5.6 ± 4 and 75 healthy controls (mean age 5.7 ± 3.4. Despite mean tract analysis, Tract-Based Spatial Statistics (TBSS and voxel-based morphometry (VBM demonstrating diffusely reduced fractional anisotropy (FA reduction in all white matter tracts, the along-tract analysis improved the detection of regional tract vulnerability. The along-tract map-structural network topology correlates revealed two associations: (1 reduced regional posterior–anterior gradient in FA of the longitudinal visual cortical association tracts (inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, optic radiation, posterior thalamic radiation correlated with reduced posterior–anterior gradient of intra-regional (nodal efficiency metrics with relative sparing of frontal and temporal regions; and (2 reduced regional FA within frontal–thalamic–striatal white matter pathways (anterior limb/anterior thalamic radiation, superior longitudinal fasciculus and cortical spinal tract

  12. Longitudinal Muscle Dysfunction in Achalasia Esophagus and Its Relevance

    OpenAIRE

    Mittal, Ravinder K.; Hong, Su Jin; Bhargava, Valmik

    2013-01-01

    Muscularis propria of the esophagus is organized into circular and longitudinal muscle layers. Goal of this review is to summarize the role of longitudinal muscle in physiology and pathophysiology of esophageal sensory and motor function. Simultaneous manometry and ultrasound imaging that measure circular and longitudinal muscle contraction respectively reveal that during peristalsis 2 layers of the esophagus contract in perfect synchrony. On the other hand, during transient relaxation of the...

  13. Effectiveness of emergency medicine in longitudinal integrated clerkships

    OpenAIRE

    Banh, Kenny; Ramirez, Rene; Thabit, Christina

    2014-01-01

    Objective: This study investigated third-year students’ experience with the emergency medicine (EM) component in integrated longitudinal programs. The study aimed to see if EM could be integrated into third-year integrated longitudinal programs while addressing accreditation standards and increasing interest in EM.Methods: The authors surveyed students who participated in an integrated longitudinal program at University of California San Francisco School of Medicine (UCSF) from 2010 to 2012. ...

  14. EXPERIMENTAL INVESTIGATIONS ON LONGITUDINAL DISPERSION CHARACTERISTICS OF TIDAL RIVERS

    Institute of Scientific and Technical Information of China (English)

    Fan Jing-yu; Wang Dao-zeng; Zhong Bao-chang

    2003-01-01

    The longitudinal dispersion characteristics of tidal rivers are experimentally investigated in a water channel. The longitudinal dispersion features and influential factors on pollutant in various stages of a tidal period in natural rivers are studied, the value ranges and variation trends of the longitudinal dispersion coefficient are obtained by means of concentration measurement. The results can provide important parameters for establishing the water quality mathematical models in tidal rivers.

  15. Indian populations

    CERN Multimedia

    Spahni,J

    1974-01-01

    Le Prof. J.C. Spahni qui a parcouru les Andes, Vénezuela etc. parle de ses expériences et connaissances qu'il a vécu au cours des 14 ans parmi les populations indiennes de la Cordillière des Andes. Il a ramené des objets artisanals indiens lesquels l'auditoire peut acquérir. L'introduction-conférence est suivi d'un film, commenté par lui-même; après l'entracte il y un débat-dialogue avec le public.

  16. ANALYSING LONGITUDINAL TURBULENCE INTENSITY IN VEGETATED CHANNELS

    Directory of Open Access Journals (Sweden)

    Francesco Giuseppe Carollo

    2007-12-01

    Full Text Available Vegetation altering hydrodynamic conditions of an open channel flow controls the exchanges of sediment, nutrients and contaminants. In this paper the turbulence structure of open-channel flow over a flexible grass vegetation is investigated. Velocity measurements were carried out, in a rectangular flume, using a 2D-ADV (Acoustic Doppler Velocimeter for different values of stem concentration, water discharge, and bed slope. The experimental results showed that: 1 the maximum value of the longitudinal turbulence intensity occurs at a water depth close to the bent vegetation height; 2 the turbulence intensity damps for increasing values of the stem concentration; 3 above the vegetation height, an exponential distribution, similar to Nezu’s law, can be fitted to the measured longitudinal turbulence intensity profile. Finally, a new relative turbulence intensity distribution is proposed and fitted to the measured profiles. This relative turbulence intensity distribution needs the estimate of two parameters coinciding with the vegetation height and the water depth at which the maximum flow velocity occurs.

  17. Longitudinal emittance measurements at REX-ISOLDE

    CERN Document Server

    Fraser, M A; Jones, R.M.; Jones, R M; Pasini, M; Posocco, P A; Voulot, D; Wenander, F

    2012-01-01

    We report on measurements of the longitudinal emittance at the Radioactive ion beam EXperiment (REX) at ISOLDE, CERN. The rms longitudinal emittance was measured as 0.34 ± 0.08 π ns keV/u at the output of the RFQ and as 0.36 ± 0.04π ns keV/u in front of the third 7-gap split-ring resonator (7G3) using the three-gradient technique; systematic errors are not included but are estimated at approximately 10%. The 86% emittance was measured a factor of approximately 4.4 times larger than the rms emittance at 1.48 ± 0.2 and 1.55 ± 0.12π ns keV/u at the RFQ and 7G3, respectively. The REX switchyard magnet was used as a spectrometer to analyse the energy spread of the beam as it was manipulated by varying the voltage of the rebuncher (ReB) and 7G3 cavities operating at non-accelerating phases. The transfer matrix for a multi-gap bunching cavity is derived and suitably truncated to allow for the accurate reconstruction of the beam parameters from measurement. The technique for measuring the energy spread was rig...

  18. Splinting of Longitudinal Fracture: An Innovative Approach

    Directory of Open Access Journals (Sweden)

    Rashmi Bansal

    2016-01-01

    Full Text Available Trauma may result in craze lines on the enamel surface, one or more fractured cusps of posterior teeth, cracked tooth syndrome, splitting of posterior teeth, and vertical fracture of root. Out of these, management of some fractures is of great challenge and such teeth are generally recommended for extraction. Literature search reveals attempts to manage such fractures by full cast crown, orthodontic wires, and so forth, in which consideration was given to extracoronal splinting only. However, due to advancement in materials and technologies, intracoronal splinting can be achieved as well. In this case report, longitudinal fractures in tooth #27, tooth #37, and tooth #46 had occurred. In #27, fracture line was running mesiodistally involving the pulpal floor resulting in a split tooth. In teeth 37 and 46, fractures of the mesiobuccal cusp and mesiolingual cusp were observed, respectively. They were restored with cast gold inlay and full cast crown, respectively. Longitudinal fracture of 27 was treated with an innovative approach using intracanal reinforced composite with Ribbond, external reinforcement with an orthodontic band, and full cast metal crown to splint the split tooth.

  19. Longitudinal residual stresses in boron fibers

    Science.gov (United States)

    Behrendt, D. R.

    1976-01-01

    A technique is proposed for measuring the longitudinal residual stress distribution in commercial CVD (Chemical Vapor Deposition) boron on tungsten fibers of 102, 142, and 203 microns in diameter. The experimental apparatus is so designed that continuous measurements are made of the length changes of a boron fiber specimen as the surface of the fiber is removed by electropolishing. The effects of surface removal on core residual stress and core-initiated fracture are discussed. The three sizes of boron fibers investigated show similar residual stress distributions, i.e., compressive at the surface, tensile near the core, and for the 102-micron fiber compressive again in the core. It is shown that an increase in UTS is due to the increase in the compressive stress at the core produced by fiber contraction during surface removal. An expression is derived for calculating the longitudinal residual stress at a given radius for an as-received fiber of a certain radius from measurements of the axial strain produced by removal of the surface by electropolishing.

  20. Mixture latent autoregressive models for longitudinal data

    CERN Document Server

    Bartolucci, Francesco; Pennoni, Fulvia

    2011-01-01

    Many relevant statistical and econometric models for the analysis of longitudinal data include a latent process to account for the unobserved heterogeneity between subjects in a dynamic fashion. Such a process may be continuous (typically an AR(1)) or discrete (typically a Markov chain). In this paper, we propose a model for longitudinal data which is based on a mixture of AR(1) processes with different means and correlation coefficients, but with equal variances. This model belongs to the class of models based on a continuous latent process, and then it has a natural interpretation in many contexts of application, but it is more flexible than other models in this class, reaching a goodness-of-fit similar to that of a discrete latent process model, with a reduced number of parameters. We show how to perform maximum likelihood estimation of the proposed model by the joint use of an Expectation-Maximisation algorithm and a Newton-Raphson algorithm, implemented by means of recursions developed in the hidden Mark...

  1. Longitudinal emission tomography of thyroid and heart

    International Nuclear Information System (INIS)

    In this thesis three devices are discussed for longitudinal emission tomography, one of which has been developed for myocardial imaging and the other two for thyroid imaging. Longitudinal emission tomography is a technique which enables three-dimensional reconstruction of the radioactivity distribution within an organ from two-dimensional distributions on a detector surface. In Ch. 1 a general survey is given of the clinical environment in which the devices will be used. Ch. 2 discusses a well-known technique for myocardial imaging: seven-pinhole tomography. In Ch. 3 this technique is applied to imaging of the thyroid. Three different reconstruction methods have been applied to the data collected with the system (from phantoms as well as from patients) and the results have been evaluated. Ch. 4 discusses simulation studies which were carried out in order to investigate the potentialities of a time-coded aperture (TCA) system designed for thyroid tomography. In Ch. 5 a prototype is tested of the time coded aperture in a clinical environment. The last chapter presents a comparison between the (thyroid) 7P collimator and the TCA device. (Auth.)

  2. Sufficient dimension reduction for longitudinally measured predictors.

    Science.gov (United States)

    Pfeiffer, Ruth M; Forzani, Liliana; Bura, Efstathia

    2012-09-28

    We propose a method to combine several predictors (markers) that are measured repeatedly over time into a composite marker score without assuming a model and only requiring a mild condition on the predictor distribution. Assuming that the first and second moments of the predictors can be decomposed into a time and a marker component via a Kronecker product structure that accommodates the longitudinal nature of the predictors, we develop first-moment sufficient dimension reduction techniques to replace the original markers with linear transformations that contain sufficient information for the regression of the predictors on the outcome. These linear combinations can then be combined into a score that has better predictive performance than a score built under a general model that ignores the longitudinal structure of the data. Our methods can be applied to either continuous or categorical outcome measures. In simulations, we focus on binary outcomes and show that our method outperforms existing alternatives by using the AUC, the area under the receiver-operator characteristics (ROC) curve, as a summary measure of the discriminatory ability of a single continuous diagnostic marker for binary disease outcomes.

  3. Tunable Mechanical Filter for Longitudinal Vibrations

    Directory of Open Access Journals (Sweden)

    S. Asiri

    2007-01-01

    Full Text Available This paper presents both theoretically and experimentally a new kind of vibration isolator called tunable mechanical filter which consists of four parallel hybrid periodic rods connected between two plates. The rods consist of an assembly of periodic cells, each cell being composed of a short rod and piezoelectric inserts. By actively controlling the piezoelectric elements, it is shown that the periodic rods can efficiently attenuate the propagation of vibration from the upper plate to the lower one within critical frequency bands and consequently minimize the effects of transmission of undesirable vibration and sound radiation. In such a filter, longitudinal waves can propagate from the vibration source in the upper plate to the lower one along the rods only within specific frequency bands called the “Pass Bands” and wave propagation is efficiently attenuated within other frequency bands called the “Stop Bands”. The spectral width of these bands can be tuned according to the nature of the external excitation. The theory governing the operation of this class of vibration isolator is presented and their tunable filtering characteristics are demonstrated experimentally as functions of their design parameters. The concept of this mechanical filter as presented can be employed in many applications to control the wave propagation and the force transmission of longitudinal vibrations both in the spectral and spatial domains in an attempt to stop/attenuate the propagation of undesirable disturbances.

  4. Longitudinal brain MRI analysis with uncertain registration.

    Science.gov (United States)

    Simpson, Ivor J A; Woolrich, Mark W; Groves, Adrian R; Schnabel, Julia A

    2011-01-01

    In this paper we propose a novel approach for incorporating measures of spatial uncertainty, which are derived from non-rigid registration, into spatially normalised statistics. Current approaches to spatially normalised statistical analysis use point-estimates of the registration parameters. This is limiting as the registration will rarely be completely accurate, and therefore data smoothing is often used to compensate for the uncertainty of the mapping. We derive localised measurements of spatial uncertainty from a probabilistic registration framework, which provides a principled approach to image smoothing. We evaluate our method using longitudinal deformation features from a set of MR brain images acquired from the Alzheimer's Disease Neuroimaging Initiative. These images are spatially normalised using our probabilistic registration algorithm. The spatially normalised longitudinal features are adaptively smoothed according to the registration uncertainty. The proposed adaptive smoothing shows improved classification results, (84% correct Alzheimer's Disease vs. controls), over either not smoothing (79.6%), or using a Gaussian filter with sigma = 2mm (78.8%). PMID:21995084

  5. Splinting of Longitudinal Fracture: An Innovative Approach

    Science.gov (United States)

    Bansal, Rashmi; Chowdhary, Priyanka; Gurtu, Anuraag; Mehrotra, Nakul; Kishore, Abhinav

    2016-01-01

    Trauma may result in craze lines on the enamel surface, one or more fractured cusps of posterior teeth, cracked tooth syndrome, splitting of posterior teeth, and vertical fracture of root. Out of these, management of some fractures is of great challenge and such teeth are generally recommended for extraction. Literature search reveals attempts to manage such fractures by full cast crown, orthodontic wires, and so forth, in which consideration was given to extracoronal splinting only. However, due to advancement in materials and technologies, intracoronal splinting can be achieved as well. In this case report, longitudinal fractures in tooth #27, tooth #37, and tooth #46 had occurred. In #27, fracture line was running mesiodistally involving the pulpal floor resulting in a split tooth. In teeth 37 and 46, fractures of the mesiobuccal cusp and mesiolingual cusp were observed, respectively. They were restored with cast gold inlay and full cast crown, respectively. Longitudinal fracture of 27 was treated with an innovative approach using intracanal reinforced composite with Ribbond, external reinforcement with an orthodontic band, and full cast metal crown to splint the split tooth. PMID:27247808

  6. Bootstrap inference longitudinal semiparametric regression model

    Science.gov (United States)

    Pane, Rahmawati; Otok, Bambang Widjanarko; Zain, Ismaini; Budiantara, I. Nyoman

    2016-02-01

    Semiparametric regression contains two components, i.e. parametric and nonparametric component. Semiparametric regression model is represented by yt i=μ (x˜'ti,zt i)+εt i where μ (x˜'ti,zt i)=x˜'tiβ ˜+g (zt i) and yti is response variable. It is assumed to have a linear relationship with the predictor variables x˜'ti=(x1 i 1,x2 i 2,…,xT i r) . Random error εti, i = 1, …, n, t = 1, …, T is normally distributed with zero mean and variance σ2 and g(zti) is a nonparametric component. The results of this study showed that the PLS approach on longitudinal semiparametric regression models obtain estimators β˜^t=[X'H(λ)X]-1X'H(λ )y ˜ and g˜^λ(z )=M (λ )y ˜ . The result also show that bootstrap was valid on longitudinal semiparametric regression model with g^λ(b )(z ) as nonparametric component estimator.

  7. Crash and rebound of indigenous populations in lowland South America

    Science.gov (United States)

    Hamilton, Marcus J.; Walker, Robert S.; Kesler, Dylan C.

    2014-04-01

    Lowland South America has long been a battle-ground between European colonization and indigenous survival. Initial waves of European colonization brought disease epidemics, slavery, and violence that had catastrophic impacts on indigenous cultures. In this paper we focus on the demography of 238 surviving populations in Brazil. We use longitudinal censuses from all known indigenous Brazilian societies to quantify three demographic metrics: 1) effects of European contact on indigenous populations; 2) empirical estimates of minimum viable population sizes; and 3) estimates of post-contact population growth rates. We use this information to conduct population viability analysis (PVA). Our results show that all surviving populations suffered extensive mortality during, and shortly after, contact. However, most surviving populations exhibit positive growth rates within the first decade post-contact. Our findings paint a positive demographic outlook for these indigenous populations, though long-term survival remains subject to powerful externalities, including politics, economics, and the pervasive illegal exploitation of indigenous lands.

  8. Use of longitudinal data in genetic studies in the genome-wide association studies era: summary of Group 14.

    Science.gov (United States)

    Kerner, Berit; North, Kari E; Fallin, M Daniele

    2009-01-01

    Participants analyzed actual and simulated longitudinal data from the Framingham Heart Study for various metabolic and cardiovascular traits. The genetic information incorporated into these investigations ranged from selected single-nucleotide polymorphisms to genome-wide association arrays. Genotypes were incorporated using a broad range of methodological approaches including conditional logistic regression, linear mixed models, generalized estimating equations, linear growth curve estimation, growth modeling, growth mixture modeling, population attributable risk fraction based on survival functions under the proportional hazards models, and multivariate adaptive splines for the analysis of longitudinal data. The specific scientific questions addressed by these different approaches also varied, ranging from a more precise definition of the phenotype, bias reduction in control selection, estimation of effect sizes and genotype associated risk, to direct incorporation of genetic data into longitudinal modeling approaches and the exploration of population heterogeneity with regard to longitudinal trajectories. The group reached several overall conclusions: (1) The additional information provided by longitudinal data may be useful in genetic analyses. (2) The precision of the phenotype definition as well as control selection in nested designs may be improved, especially if traits demonstrate a trend over time or have strong age-of-onset effects. (3) Analyzing genetic data stratified for high-risk subgroups defined by a unique development over time could be useful for the detection of rare mutations in common multifactorial diseases. (4) Estimation of the population impact of genomic risk variants could be more precise. The challenges and computational complexity demanded by genome-wide single-nucleotide polymorphism data were also discussed. PMID:19924713

  9. Spiritual stress and coping model of divorce: a longitudinal study.

    Science.gov (United States)

    Krumrei, Elizabeth J; Mahoney, Annette; Pargament, Kenneth I

    2011-12-01

    This study represents the first longitudinal effort to use a spiritual stress and coping model to predict adults' psychosocial adjustment following divorce. A community sample of 89 participants completed measures at the time of their divorce and 1 year later. Though the sample endorsed slightly lower levels of religiosity than the general U.S. population, most reported spiritual appraisals and positive and negative religious coping tied to divorce. Hierarchical regression analyses controlling general religiousness and nonreligious forms of coping indicated that (a) appraising divorce as a sacred loss or desecration at the time it occurred predicted more depressive symptoms and dysfunctional conflict tactics with the ex-spouse 1 year later; (b) positive religious coping reported about the year following divorce predicted greater posttraumatic growth 1 year after divorce; and (c) negative religious coping reported about the year following divorce predicted more depressive symptoms 1 year after the divorce. Bootstrapping mediation analyses indicated that negative religious coping fully mediated links between appraising the divorce as a sacred loss or desecration at the time it occurred and depressive symptoms 1 year later. In addition, moderation analyses revealed that negative religious coping is more strongly associated with depressive symptoms among those who form high versus low appraisals of their divorce as a sacred loss or desecration. These findings are relevant to divorce education and intervention provided by professionals in legal, family, mental health, and clerical roles. Implications are discussed for clinical and counseling psychology and religious communities.

  10. Design for a Longitudinal Density Monitor for the LHC

    CERN Document Server

    Bart Pedersen, S; Boccardi, A; Fisher, AS; Jeff, A; Lefevre, T; Rabiller, A; Roncarolo, F; Welsch, CP

    2010-01-01

    Synchrotron radiation is currently used on the LHC for beam imaging and for monitoring the proton population in the 3 microsecond abort gap. In addition to these existing detectors, a study has been initiated to provide longitudinal density profiles of the LHC beams with a high dynamic range and a 50ps time resolution. This would allow for the precise measurement both of the bunch shape and the number of particles in the bunch tail or drifting into ghost bunches. A solution is proposed based on counting synchrotron light photons with two fast avalanche photo-diodes (APD) operated in Geiger mode. One is free-running but heavily attenuated and can be used to measure the core of the bunch. The other is much more sensitive, for measurement of the bunch tails, but must be gated off during the passage of the bunch to prevent the detector from being swamped. An algorithm is then applied to combine the two measurements and correct for the detector dead-time, after pulsing and pileup effects. Initial results from labo...

  11. Design for a Longitudinal Density Monitor for the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Jeff, Adam; /CERN; Bart Pedersen, Stephane; /CERN; Boccardi, Andrea; /CERN; Bravin, Enrico; /CERN; Lefevre, Thibaut; /CERN; Rabiller, Aurelie; /CERN; Roncarolo, Federico; /CERN; Fisher, Alan; /SLAC; Welsch, Carsten; /Liverpool U.

    2012-07-13

    Synchrotron radiation is currently used on the LHC for beam imaging and for monitoring the proton population in the 3 microsecond abort gap. In addition to these existing detectors, a study has been initiated to provide longitudinal density profiles of the LHC beams with a high dynamic range and a 50ps time resolution. This would allow for the precise measurement both of the bunch shape and the number of particles in the bunch tail or drifting into ghost bunches. A solution is proposed based on counting synchrotron light photons with two fast avalanche photo-diodes (APD) operated in Geiger mode. One is free-running but heavily attenuated and can be used to measure the core of the bunch. The other is much more sensitive, for measurement of the bunch tails, but must be gated off during the passage of the bunch to prevent the detector from being swamped. An algorithm is then applied to combine the two measurements and correct for the detector dead-time, afterpulsing and pile-up effects. Initial results from laboratory testing of this system are described here.

  12. International longitudinal pediatric reference standards for bone mineral content.

    Science.gov (United States)

    Baxter-Jones, Adam D G; Burrows, Melonie; Bachrach, Laura K; Lloyd, Tom; Petit, Moira; Macdonald, Heather; Mirwald, Robert L; Bailey, Don; McKay, Heather

    2010-01-01

    To render a diagnosis pediatricians rely upon reference standards for bone mineral density or bone mineral content, which are based on cross-sectional data from a relatively small sample of children. These standards are unable to adequately represent growth in a diverse pediatric population. Thus, the goal of this study was to develop sex and site-specific standards for BMC using longitudinal data collected from four international sites in Canada and the United States. Data from four studies were combined; Saskatchewan Paediatric Bone Mineral Accrual Study (n=251), UBC Healthy Bones Study (n=382); Penn State Young Women's Health Study (n=112) and Stanford's Bone Mineral Accretion study (n=423). Males and females (8 to 25 years) were measured for whole body (WB), total proximal femur (PF), femoral neck (FN) and lumbar spine (LS) BMC (g). Data were analyzed using random effects models. Bland-Altman was used to investigate agreement between predicted and actual data. Age, height, weight and ethnicity independently predicted BMC accrual across sites (PZ-score, accounting for age, size, sex and ethnicity. In conclusion, when interpreting BMC in pediatrics we recommend standards that are sex, age, size and ethnic specific. PMID:19854308

  13. Population Genetics with Fluctuating Population Sizes

    CERN Document Server

    Chotibut, Thiparat

    2016-01-01

    Standard neutral population genetics theory with a strictly fixed population size has important limitations. An alternative model that allows independently fluctuating population sizes and reproduces the standard neutral evolution is reviewed. We then study a situation such that the competing species are neutral at the equilibrium population size but population size fluctuations nevertheless favor fixation of one species over the other. In this case, a separation of timescales emerges naturally and allows adiabatic elimination of a fast population size variable to deduce the fluctuations-induced selection dynamics near the equilibrium population size. The results highlight the incompleteness of the standard population genetics with a strictly fixed population size.

  14. Trends and determinant factors for population blood pressure with 25 years of follow-up: results from the Copenhagen City Heart Study

    DEFF Research Database (Denmark)

    Andersen, Ulla Overgaard; Jensen, Gorm B

    2010-01-01

    OBJECTIVE: This study aimed to evaluate within-population trends in population blood pressure (BP) over 25 years and to identify important determinants for a changing population BP. DESIGN: Copenhagen City Heart Study is a prospective longitudinal epidemiological study. The study population (15 5...

  15. Need for longitudinal studies of Asian wildlife in the face of crises

    Directory of Open Access Journals (Sweden)

    Shermin de Silva

    2016-04-01

    Full Text Available Conservation biology is conceived as a discipline that must balance the short-term aim of gathering data on pressing conservation issues with the long-term vision of protecting populations, species, and functional ecosystems. Asian wildlife face imminent threats ranging from hunting to loss of critical habitats, but there are few examples of detailed longitudinal wildlife research in the region. Longitudinal research is essential for protecting populations especially in light of the high volumes of legal and illegal trade, understanding basic population dynamics, notably with respect to long-lived species, as well as accommodating the spatial needs of animals. It is also critical for evaluating the success of conservation or management interventions and adaptively improving outcomes. Such studies, particularly when requiring sustained field work, are impeded by mismatches between needs on the ground vs. the priorities of different stakeholders, the ephemeral and inefficient nature of funding mechanisms, and by the logistics of maintaining sites and personnel. Yet we cannot adequately protect biodiversity in Asia unless the magnitude of human impacts on its species is quantitatively understood and used to inform management.

  16. Linear mixed models for longitudinal data

    CERN Document Server

    Molenberghs, Geert

    2000-01-01

    This paperback edition is a reprint of the 2000 edition. This book provides a comprehensive treatment of linear mixed models for continuous longitudinal data. Next to model formulation, this edition puts major emphasis on exploratory data analysis for all aspects of the model, such as the marginal model, subject-specific profiles, and residual covariance structure. Further, model diagnostics and missing data receive extensive treatment. Sensitivity analysis for incomplete data is given a prominent place. Several variations to the conventional linear mixed model are discussed (a heterogeity model, conditional linear mixed models). This book will be of interest to applied statisticians and biomedical researchers in industry, public health organizations, contract research organizations, and academia. The book is explanatory rather than mathematically rigorous. Most analyses were done with the MIXED procedure of the SAS software package, and many of its features are clearly elucidated. However, some other commerc...

  17. Tomographic Measurements of Longitudinal Phase Space Density

    CERN Document Server

    Hancock, S; Lindroos, M

    1998-01-01

    Tomography is now a very broad topic with a wealth of algorithms for the reconstruction of both qualitative and quantitative images. One of the simplest algorithms has been modified to take into accou nt the non-linearity of large-amplitude synchrotron motion. This permits the accurate reconstruction of longitudinal phase space density from one-dimensional bunch profile data. The method is a hybrid one which incorporates particle tracking, and considerable effort has been invested to optimize the computer code so that it may also be compiled to exploit parallel architectures efficiently. A selec tion of the results obtained at different CERN accelerators is presented. The starting-point in each case is simply a "mountain range" of digitized bunch profiles.

  18. Van Kampen modes for bunch longitudinal motion

    Energy Technology Data Exchange (ETDEWEB)

    Burov, A.; /Fermilab

    2010-09-01

    Conditions for existence, uniqueness and stability of bunch steady states are considered. For the existence uniqueness problem, simple algebraic equations are derived, showing the result both for the action and Hamiltonian domain distributions. For the stability problem, van Kampen theory is used. Emerging of discrete van Kampen modes show either loss of Landau damping, or instability. This method can be applied for an arbitrary impedance, RF shape and beam distribution function Available areas on intensity-emittance plane are shown for resistive wall wake and single harmonic, bunch shortening and bunch lengthening RF configurations. Language of van Kampen modes is a powerful tool for studying beam stability. Its unique efficiency reveals itself in those complicated cases, when the dielectric function cannot be obtained, as it is for the longitudinal bunch motion. Emergence of a discrete mode means either loss of Landau damping or instability. By definition, the discrete modes lie outside the continuous incoherent spectrum, but they still may stay within the bucket. In the last case, the discrete mode would disappear after a tiny portion of resonant particles would be added. However, if the discrete mode lie outside the bucket, the Landau damping cannot be restored by tiny perturbation of the particle distribution; LLD is called radical in that case. For a given bunch emittance and RF voltage, the intensity is limited either by reduction of the bucket acceptance or by (radical) LLD. In this paper, results are presented for longitudinal bunch stability in weak head-tail approximation and resistive wall impedance; three RF configurations are studied: single harmonic, bunch shortening and bunch lengthening. It is shown that every RF configuration may be preferable, depending on the bunch emittance and intensity.

  19. Psychosocial adjustment to ALS: a longitudinal study

    Directory of Open Access Journals (Sweden)

    Tamara eMatuz

    2015-09-01

    Full Text Available For the current study the Lazarian stress-coping theory and the appendant model of psychosocial adjustment to chronic illness and disabilities (Pakenham 1999 has shaped the foundation for identifying determinants of adjustment to ALS. We aimed to investigate the evolution of psychosocial adjustment to ALS and to determine its long-term predictors. A longitudinal study design with four measurement time points was therefore, used to assess patients’ quality of life, depression, and stress-coping model related aspects, such as illness characteristics, social support, cognitive appraisals and coping strategies during a period of two years. Regression analyses revealed that 55% of the variance of severity of depressive symptoms and 47% of the variance in quality of life at T2 was accounted for by all the T1 predictor variables taken together. On the level of individual contributions, protective buffering and appraisal of own coping potential accounted for a significant percentage in the variance in severity of depressive symptoms, whereas problem management coping strategies explained variance in quality of life scores. Illness characteristics at T2 did not explain any variance of both adjustment outcomes. Overall, the pattern of the longitudinal results indicated stable depressive symptoms and quality of life indices reflecting a successful adjustment to the disease across four measurement time points during a period of about two years.Empirical evidence is provided for the predictive value of social support, cognitive appraisals, and coping strategies, but not illness parameters such as severity and duration for adaptation to ALS. The current study contributes to a better conceptualization of adjustment, allowing us to provide evidence-based support beyond medical and physical intervention for people with ALS.

  20. Learning from Longitudinal Research in Criminology and the Health Sciences

    Science.gov (United States)

    Vanderstaay, Steven L.

    2006-01-01

    This article reviews longitudinal research within criminology and the health sciences on the relationship between reading and criminal, delinquent, or antisocial behavior. Longitudinal research in criminology, medicine, and psychology examines the role of reading within a broad set of interactive processes, connecting literacy to public health via…

  1. 14 CFR 23.175 - Demonstration of static longitudinal stability.

    Science.gov (United States)

    2010-01-01

    ... stability. 23.175 Section 23.175 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Flight Stability § 23.175 Demonstration of static longitudinal stability. Static longitudinal stability must be shown as follows: (a) Climb. The stick force curve must have a stable slope at speeds...

  2. Longitudinal electromagnetic waves in the framework of standard classical electrodynamics

    CERN Document Server

    Simulik, V M

    2016-01-01

    The link between the longitudinal electromagnetic waves and the system of Maxwell equations is demonstrated. The longitudinal wave component of the electric field strength vector is found as the exact solution of the standard Maxwell equations with specific gradient-type case of electric current and charge densities.

  3. The modified electromagnetism and the emergent longitudinal wave

    OpenAIRE

    Arbab, Arbab I.; Al-Ajmi, Mudhahir

    2014-01-01

    The classical theory of electromagnetism has been revisited and the possibility of longitudinal photon wave is explored. It is shown that the emergence of longitudinal wave is a consequence of Lorenz gauge (condition) violation. Proca, Vlaenderen & Waser and Arbab theories are investigated.

  4. The Work Experiences of New SSI Beneficiaries: A Longitudinal Perspective.

    OpenAIRE

    Yonatan Ben-Shalom; David Stapleton

    2012-01-01

    This issue brief uses longitudinal data to follow a group of Social Security Insurance beneficiaries and examine their efforts to return to work. Compared with shorter-term cross-sectional data, the longitudinal statistics show higher levels of employment and suspensions of benefits due to work.

  5. Longitudinal Outcomes for Mathematics Achievement for Students with Learning Disabilities

    Science.gov (United States)

    Judge, Sharon; Watson, Silvana M. R.

    2011-01-01

    Using longitudinal data from the first 6 waves of the Early Childhood Longitudinal Study-Kindergarten Cohort (ECLS-K), the authors examined mathematics achievement and growth trajectories by learning disability (LD) subgroups. The 2-level (time-student) growth curve model showed that lower levels of mathematics achievement were already evident at…

  6. Early Predictors of Adolescent Depression: A 7-Year Longitudinal Study

    Science.gov (United States)

    Mazza, James J.; Abbott, Robert D.; Fleming, Charles B.; Harachi, Tracy W.; Cortes, Rebecca C.; Park, Jisuk; Haggerty, Kevin P.; Catalano, Richard F.

    2009-01-01

    This study examined the longitudinal relationship of early elementary predictors to adolescent depression 7 years later. The sample consisted of 938 students who have been part of a larger longitudinal study that started in 1993. Data collected from parents, teachers, and youth self-reports on early risk factors when students were in 1st and 2nd…

  7. A Reference Optical System of Laser Doppler Longitudinal Displacement Measurement

    Institute of Scientific and Technical Information of China (English)

    张存满; 赵洋; 李达成

    2001-01-01

    In this paper, a new reference optical system is put forward to achieve longitudinal displacement measurement. An optical grating is used for frequency mixing and getting high SNR signals in the measurement. Conditions and methods for getting Doppler beat signals are presented.The experiments indicate that this optical syetem can be used to measure the longitudinal displacement with high accuracy.

  8. Longitudinal and transverse polarizations in the deep inelastic reactions

    International Nuclear Information System (INIS)

    This course is an introduction to the dominant effects of longitudinal and transverse spin in deep inelastic reactions. Only the effects present to the 'leading twist' are attacked. The mass and transverse impulsion of partons are neglected. We will attach to bring out the respective specificities of longitudinal and transverse polarizations. (N.C.)

  9. Longitudinal Trajectories of Perceived Body Weight: Adolescence to Early Adulthood

    Science.gov (United States)

    Seo, Dong-Chul; Li, Kaigang

    2012-01-01

    Objective: To examine longitudinal trajectories of perceived weight from adolescence to early adulthood by gender. Methods: We analyzed 9 waves (1997-2005) of data from the National Longitudinal Survey of Youth (N = 8302) using Mplus. Results: Perceived overweight increased over time among girls and did not level off until 23 years of age. Blacks…

  10. A nonparametric dynamic additive regression model for longitudinal data

    DEFF Research Database (Denmark)

    Martinussen, Torben; Scheike, Thomas H.

    2000-01-01

    dynamic linear models, estimating equations, least squares, longitudinal data, nonparametric methods, partly conditional mean models, time-varying-coefficient models......dynamic linear models, estimating equations, least squares, longitudinal data, nonparametric methods, partly conditional mean models, time-varying-coefficient models...

  11. Body Image Distortions, Weight, and Depression in Adolescent Boys: Longitudinal Trajectories into Adulthood.

    Science.gov (United States)

    Blashill, Aaron J; Wilhelm, Sabine

    2014-01-01

    Depressive symptoms are common among the U.S. population, yet research into prospective risk factors of depression among men is limited. Distorted body image is also prevalent among adolescent boys, and may be linked with elevated depression; however, longitudinal associations have rarely been measured. Thus, the aim of the current study was to assess the prospective relationship between forms of body image distortion and depressive symptoms among adolescent boys, into adulthood. Data were extracted from the National Longitudinal Study of Adolescent Health. Participants were 2,139 U.S. adolescent boys (M age = 16) who were followed prospectively over 13-years (1996 to 2009), into adulthood. Longitudinal mixed-level modeling was employed to assess the temporal prediction of body image distortion on symptoms of depression. Results revealed that boys who were average weight and viewed themselves as either very underweight (very underweight distorted; Cohen's d = .47) or overweight (overweight distorted; Cohen's d = .29) reported significantly higher levels of depressive symptoms compared to boys who accurately viewed their weight as average; this effect remained constant over the 13-year study period. These findings indicated that distortions in body image, particularly extreme distortions, are risk factors for elevated depressive symptoms among adolescent boys, and persist into early adulthood. PMID:25383047

  12. Periodontal bone height in professional musicians. Cross-sectional and longitudinal aspects.

    Science.gov (United States)

    Stamatakis, H C; Eliasson, S; Bergström, J

    1999-04-01

    Cross-sectional and longitudinal studies of the periodontal bone height were performed on professional musicians playing wind and non-wind instruments. The cross-sectional study population included 244 occupational musicians (186 men and 58 women aged 20-69 years) from three Swedish national orchestras. Eighty-seven were wind instrument musicians. Radiographic full-mouth surveys were performed and the periodontal bone height was measured with a computerized method and expressed as a percentage of the root length. The mean periodontal bone height was 83.4% for the musicians playing wind instruments and 83.6% for those playing non-wind instruments. There was no statistically significant difference in periodontal bone height between the two instrumentalist categories. In addition, the bone height quotients of anterior to posterior teeth were analyzed but no significant differences were found between wind and non-wind instrumentalists. A longitudinal cohort including 92 musicians who had been examined in a corresponding study 10 years earlier was studied. The overall loss of the periodontal bone height over the 10-year period was small, but only wind instrumentalists of the 50-69 year age group exhibited a statistically significant reduction over time. There was no statistically significant difference between musicians as regards instrument played. It is concluded from the cross-sectional and 10-year longitudinal observations that the playing of wind instruments is unlikely to affect periodontal bone height. PMID:10445366

  13. Oral health changes in an adult Norwegian population : a cohort analytical approach

    NARCIS (Netherlands)

    Holst, D; Schuller, A A

    2000-01-01

    OBJECTIVES: The purpose of this analysis was to study temporal variation in oral health in an adult population. The cohort analysis comprised 1) estimation of longitudinal, cross-sectional, and time-lag differences in caries and treatment experience of the adult population in Trøndelag from 1973 to

  14. Longitudinal RF capture and acceleration simulation in CSNS RCS

    Institute of Scientific and Technical Information of China (English)

    LIU Lin; TANG Jing-Yu; QIU Jing; WEI Tao

    2009-01-01

    China Spallation Neutron Source(CSNS)is a high power proton accelerator-based facility.Uncontrolled beam loss is a major concern in designing the CSNS to control the radioactivation level.For the Rapid Cycling Synchrotron(RCS)of the CSNS,the repetition frequency is too high for the longitudinal motion to be fully adiabatic.Significant beam loss happens during the RF capture and initial acceleration of the injection period.To reduce the longitudinal beam loss,beam chopping and momentum offset painting methods are used in the RCS injection.This paper presents detailed studies on the longitudinal motion in the RCS by using the ORBIT simulations,which include different beam chopping factors,momentum offsets and RF voltage optimization.With a trade-off between the longitudinal beam loss and transverse incoherent tune shift that will also result in beam losses,optimized longitudinal painting schemes are obtained.

  15. Requirements for longitudinal HOM damping in superconducting recirculating linacs

    International Nuclear Information System (INIS)

    Transverse beam breakup provides the primary current limitation in the operation of superconducting recirculating linacs and requires the significant damping of transverse-deflecting higher order modes. The need to damp the coexisting longitudinal HOMs in these nominally isochronous machines, however, is not as clear. Isochronicity implies that energy variations induced by excitation of longitudinal modes do not translate directly into position and current modulations. Such modulations, if present, could enhance the initial excitation, effectively closing a potentially unstable feedback loop. Design optimization of cavity structures may suggest that no longitudinal damping be provided. On the other hand, easing of the isochronicity requirement may provide desired flexibility in lattice design. In this note, limits are placed on the requirements for longitudinal HOM damping and on the tolerances for isochronicity which are driven by possible longitudinal multipass phenomena. 2 refs., 1 fig

  16. Population, Population Density, and Technological Change

    OpenAIRE

    Klasen, Stephan; Nestmann, Thorsten

    2004-01-01

    In a model on population and endogenous technological change, Kremer combines a short-run Malthusian scenario where income determines the population that can be sustained, with the Boserupian insight that greater population spurs technological change and can therefore lift a country out of its Malthusian trap. We show that a more realistic version of the model, which combines population and population density, allows deeper insights into these processes. The incorporation of population densit...

  17. Effect of cigarette smoking on evolution of ventilatory lung function in young adults: an eight year longitudinal study.

    OpenAIRE

    Jaakkola, M S; Ernst, P.; Jaakkola, J J; N'gan'ga, L W; Becklake, M R

    1991-01-01

    BACKGROUND: There are few data on the quantitative effects of cigarette smoking on lung function in young adults. These effects are important in the understanding of the early stages of chronic airflow obstruction. METHODS: A longitudinal study over eight years was carried out to estimate quantitatively the effect of cigarette smoking on ventilatory lung function in young adults and to examine the possibility that the effect is modified by other factors. The study population were 15 to 40 yea...

  18. Free Recall Episodic Memory Performance Predicts Dementia Ten Years prior to Clinical Diagnosis: Findings from the Betula Longitudinal Study

    OpenAIRE

    Boraxbekk, Carl-Johan; Lundquist, Anders; Nordin, Annelie; Nyberg, Lars; Nilsson, Lars-Göran; Adolfsson, Rolf

    2015-01-01

    Background/Aims: Early dementia diagnosis is a considerable challenge. The present study examined the predictive value of cognitive performance for a future clinical diagnosis of late-onset Alzheimer's disease or vascular dementia in a random population sample. Methods: Cognitive performance was retrospectively compared between three groups of participants from the Betula longitudinal cohort. Group 1 developed dementia 11-22 years after baseline testing (n = 111) and group 2 after 1-10 years ...

  19. The association of early IQ and education with mortality: 65 year longitudinal study in Malmö, Sweden

    OpenAIRE

    Lager, A; Bremberg, S; Vågerö, D.

    2009-01-01

    Objectives To establish whether differences in early IQ explain why people with longer education live longer, or whether differences in father’s or own educational attainment explain why people with higher early IQ live longer. Design Population based longitudinal study. Mortality risks were estimated with Cox proportional hazards regressions. Setting Malmö, Sweden. Participants 1530 children who took IQ tests at age 10 and were followed up until age 75. Results Own educational attainment was...

  20. Percentage of Deaths Attributable to Poor Cardiovascular Health Lifestyle Factors: Findings from the Aerobics Center Longitudinal Study

    OpenAIRE

    Xuemei Sui; Hongjuan Li; Jiajia Zhang; Li Chen; Ling Zhu; Blair, Steven N.

    2013-01-01

    Purpose. We assessed the effects of the four newly defined American Heart Association (AHA) lifestyle factors on mortality by examining the associated population attributable fractions (PAFs) of these factors. Methods. Slightly modified AHA cardiovascular health factors (smoking, body mass index, cardiorespiratory fitness, and diet) were measured among 11,240 (24% women) participants from the Aerobics Center Longitudinal Study between 1987 and 1999. The cohort was followed to December 31, 200...

  1. Oropharyngeal Dysphagia in a Community-Based Elderly Cohort: the Korean Longitudinal Study on Health and Aging

    OpenAIRE

    Yang, Eun Joo; Kim, Mi Hyun; LIM, JAE-YOUNG; Paik, Nam-Jong

    2013-01-01

    This study was conducted to investigate the prevalence of dysphagia and evaluated the association of dysphagia and activities of daily living in a geriatric population residing in an independent-living facility in Korea. Korean men and women 65-yr and older living in a single, typical South Korean city (n=415) were enrolled in the Korean Longitudinal Study on Health and Aging study. Dysphagia was assessed using the Standardized Swallowing Assessment. Data were collected on activities of daily...

  2. Formal home care utilisation by older adults in Ireland: Evidence from the Irish longitudinal study on ageing

    OpenAIRE

    Murphy, Catriona; B. Whelan; Normand, C.

    2014-01-01

    The aim of this study is to provide a population based estimate of the utilisation of publicly financed formal home care by older adults in Ireland and to identify the principal characteristics of those utilising formal home care. Data were collected through computer-aided personal interviews from a representative sample of community living older adults in Ireland. The interviews were conducted between 2009 and 2011 as part of the first wave of the Irish Longitudinal Study on Ageing (TILDA). ...

  3. Psychosocial predictors of the onset of anxiety disorders in women: Results from a prospective 3-year longitudinal study

    OpenAIRE

    Calkins, Amanda W.; Otto, Michael W; Cohen, Lee S.; Soares, Claudio N.; Vitonis, Alison F.; Hearon, Bridget A.; Harlow, Bernard L.

    2009-01-01

    In a prospective, longitudinal, population-based study of 643 women participating in the Harvard Study of Moods and Cycles we examined whether psychosocial variables predicted a new or recurrent onset of an anxiety disorder. Presence of anxiety disorders was assessed every six months over three years via structured clinical interviews. Among individuals who had a new episode of anxiety, we confirmed previous findings that history of anxiety, increased anxiety sensitivity (the fear of anxiety ...

  4. Association of FTO With Obesity-Related Traits in the Cebu Longitudinal Health and Nutrition Survey (CLHNS) Cohort

    OpenAIRE

    Marvelle, Amanda F.; Lange, Leslie A.; Qin, Li; Adair, Linda S; Mohlke, Karen L

    2008-01-01

    OBJECTIVE—The underlying genetic component of obesity-related traits is not well understood, and there is limited evidence to support genetic association shared across multiple studies, populations, and environmental contexts. The present study investigated the association between candidate variants and obesity-related traits in a sample of 1,886 adult Filipino women from the Cebu Longitudinal Health and Nutrition Survey (CLHNS) cohort. RESEARCH DESIGN AND METHODS—We selected and genotyped 19...

  5. Longitudinal Investigation of Adaptive Functioning Following Conformal Irradiation for Pediatric Craniopharyngioma and Low-Grade Glioma

    Energy Technology Data Exchange (ETDEWEB)

    Netson, Kelli L. [Department of Psychiatry and Behavioral Sciences, Kansas University School of Medicine—Wichita, Kansas (United States); Conklin, Heather M. [Department of Psychology, St Jude Children' s Research Hospital, Memphis, Tennessee (United States); Wu, Shengjie; Xiong, Xiaoping [Department of Biostatistics, St Jude Children' s Research Hospital, Memphis, Tennessee (United States); Merchant, Thomas E., E-mail: thomas.merchant@stjude.org [Division of Radiation Oncology, St Jude Children' s Research Hospital, Memphis, Tennessee (United States)

    2013-04-01

    Purpose: Children treated for brain tumors with conformal radiation therapy experience preserved cognitive outcomes. Early evidence suggests that adaptive functions or independent-living skills may be spared. This longitudinal investigation prospectively examined intellectual and adaptive functioning during the first 5 years following irradiation for childhood craniopharyngioma and low-grade glioma (LGG). The effect of visual impairment on adaptive outcomes was investigated. Methods and Materials: Children with craniopharyngioma (n=62) and LGG (n=77) were treated using conformal or intensity modulated radiation therapy. The median age was 8.05 years (3.21-17.64 years) and 8.09 years (2.20-19.27 years), respectively. Serial cognitive evaluations including measures of intelligence quotient (IQ) and the Vineland Adaptive Behavior Scales (VABS) were conducted at preirradiation baseline, 6 months after treatment, and annually through 5 years. Five hundred eighty-eight evaluations were completed during the follow-up period. Results: Baseline assessment revealed no deficits in IQ and VABS indices for children with craniopharyngioma, with significant (P<.05) longitudinal decline in VABS Communication and Socialization indices. Clinical factors associated with more rapid decline included females and preirradiation chemotherapy (interferon). The only change in VABS Daily Living Skills correlated with IQ change (r=0.34; P=.01) in children with craniopharyngioma. Children with LGG performed below population norms (P<.05) at baseline on VABS Communication, Daily Living Indices, and the Adaptive Behavior Composite, with significant (P<.05) longitudinal decline limited to VABS Communication. Older age at irradiation was a protective factor against longitudinal decline. Severe visual impairment did not independently correlate with poorer adaptive outcomes for either tumor group. Conclusions: There was relative sparing of postirradiation functional outcomes over time in this sample

  6. Longitudinal Investigation of Adaptive Functioning Following Conformal Irradiation for Pediatric Craniopharyngioma and Low-Grade Glioma

    International Nuclear Information System (INIS)

    Purpose: Children treated for brain tumors with conformal radiation therapy experience preserved cognitive outcomes. Early evidence suggests that adaptive functions or independent-living skills may be spared. This longitudinal investigation prospectively examined intellectual and adaptive functioning during the first 5 years following irradiation for childhood craniopharyngioma and low-grade glioma (LGG). The effect of visual impairment on adaptive outcomes was investigated. Methods and Materials: Children with craniopharyngioma (n=62) and LGG (n=77) were treated using conformal or intensity modulated radiation therapy. The median age was 8.05 years (3.21-17.64 years) and 8.09 years (2.20-19.27 years), respectively. Serial cognitive evaluations including measures of intelligence quotient (IQ) and the Vineland Adaptive Behavior Scales (VABS) were conducted at preirradiation baseline, 6 months after treatment, and annually through 5 years. Five hundred eighty-eight evaluations were completed during the follow-up period. Results: Baseline assessment revealed no deficits in IQ and VABS indices for children with craniopharyngioma, with significant (P<.05) longitudinal decline in VABS Communication and Socialization indices. Clinical factors associated with more rapid decline included females and preirradiation chemotherapy (interferon). The only change in VABS Daily Living Skills correlated with IQ change (r=0.34; P=.01) in children with craniopharyngioma. Children with LGG performed below population norms (P<.05) at baseline on VABS Communication, Daily Living Indices, and the Adaptive Behavior Composite, with significant (P<.05) longitudinal decline limited to VABS Communication. Older age at irradiation was a protective factor against longitudinal decline. Severe visual impairment did not independently correlate with poorer adaptive outcomes for either tumor group. Conclusions: There was relative sparing of postirradiation functional outcomes over time in this sample

  7. Longitudinal Investigation into Genetics in the Conservation of Metabolic Phenotypes in Danish and Chinese Twins

    Science.gov (United States)

    Li, Shuxia; Duan, Haiping; Zhang, Dongfeng; Pang, Zengchang; Hjelmborg, Jacob; Tan, Qihua; Kruse, Torben; Dalgård, Christine

    2016-01-01

    Longitudinal twin studies on long term conservation of individual metabolic phenotypes can help to explore the genetic and environmental basis in maintaining metabolic homeostasis and metabolic health. We performed a longitudinal twin study on 12 metabolic phenotypes from Danish twins followed up for 12 years and Chinese twins traced for 7 years. The study covered a relatively large sample of 502 pairs of Danish adult twins with a mean age at intake of 38 years and a total of 181 Chinese adult twin pairs with a mean baseline age of 39.5 years. Bivariate twin models were fitted to the longitudinal measurements taken at two time points (at baseline and follow-up) to estimate the genetic and environmental contributions to phenotype variation and correlation at and between the two time points. High genetic components in the regulation of intra-individual phenotype correlation or stability over time were estimated in both Danish (h2>0.75 except fasting blood glucose) and Chinese (h2>0.72 except blood pressure) twins; moderate to high genetic contribution to phenotype variation at the two time points were also estimated except for the low genetic regulation on glucose in Danish and on blood pressure in Chinese twins. Meanwhile the bivariate twin models estimated shared environmental contributions to the variance and covariance in fasting blood glucose in Danish twins, and in systolic and diastolic blood pressure, low and high density lipoprotein cholesterol in Chinese twins. Overall, our longitudinal twin study on long-term stability of metabolic phenotypes in Danish and Chinese twins identified a common pattern of high genetic control over phenotype conservation, and at the same time revealed population-specific patterns of genetic and common environmental regulation on the variance as well as covariance of glucose and blood pressure. PMID:27618179

  8. Longitudinal associations between conduct problems and depressive symptoms among girls and boys with early conduct problems.

    Science.gov (United States)

    Poirier, Martine; Déry, Michèle; Temcheff, Caroline E; Toupin, Jean; Verlaan, Pierrette; Lemelin, Jean-Pascal

    2016-07-01

    Youth with conduct problems (CP) may experience high rates of depressive symptoms (DS). However, little is known about the direction of the longitudinal associations between CP and DS in this specific population. Although girls with CP appear at greater risk than boys for presenting comorbid depression, empirical research on gender differences in these associations is even sparser. The current study used autoregressive latent trajectory models to compare four perspectives with hypotheses regarding the longitudinal associations between CP and DS, while taking into account the evolution of both problems. We also examined gender differences in the longitudinal associations. A total of 345 children (40.6 % female) presenting with a high level of CP in early elementary school (mean age at study inception = 8.52; SD = .94) were evaluated annually over a four-year period (5 measurement time points). The results revealed that CP and DS were quite stable over time. Moreover, CP and DS showed strong covariation at each measurement time point, but only one significant positive cross-lagged association between the two processes, indicating that higher levels of DS at time 3 were associated with higher levels of CP 1 year later. No differences were observed in the longitudinal associations between CP and DS in boys and girls. Given the comorbidity and stability of CP and DS, these findings suggest that DS should be systematically evaluated among children with early clinically significant CP, and treatment plans should include interventions aimed at both CP and DS among children who present with both types of problems.

  9. Health-related quality of life is associated with physical activity levels among colorectal cancer survivors: a longitudinal, 3-year study of the PROFILES registry

    NARCIS (Netherlands)

    Husson, O.; Mols, F.; Ezendam, N.P.; Schep, G.; Poll-Franse, L.V. van de

    2015-01-01

    PURPOSE: The present study aims to examine the longitudinal relation between physical activity (PA) and health-related quality of life (HRQoL) among colorectal cancer (CRC) survivors. METHODS: Individuals diagnosed with CRC between 2000 and 2009 as registered by the Dutch population-based Eindhoven

  10. Longitudinal Surveys of Australian Youth (LSAY): 1995 Cohort--User Guide. Data Elements B1: Education. Technical Report 49B1

    Science.gov (United States)

    National Centre for Vocational Education Research (NCVER), 2009

    2009-01-01

    This technical paper contains information about the variables in the LSAY (Longitudinal Surveys of Australian Youth) Y95 cohort data set. It groups each variable into data elements which identifies common variables within and across waves. Information is provided about each data element including its purpose, values, base populations and relevant.…

  11. Longitudinal Surveys of Australian Youth (LSAY): 1995 Cohort--User Guide. Data Elements B2: Education. Technical Report 49B2

    Science.gov (United States)

    National Centre for Vocational Education Research (NCVER), 2009

    2009-01-01

    This technical paper contains information about the variables in the Longitudinal Surveys of Australian Youth (LSAY) Year 95 cohort data set. It groups each variable into data elements that identify common variables within and across waves. Information is provided about each data element, including its purpose, values, base populations and…

  12. Longitudinal phase space tomography with space charge

    International Nuclear Information System (INIS)

    Tomography is now a very broad topic with a wealth of algorithms for the reconstruction of both qualitative and quantitative images. In an extension in the domain of particle accelerators, one of the simplest algorithms has been modified to take into account the non-linearity of large-amplitude synchrotron motion. This permits the accurate reconstruction of longitudinal phase space density from one-dimensional bunch profile data. The method is a hybrid one which incorporates particle tracking. Hitherto, a very simple tracking algorithm has been employed because only a brief span of measured profile data is required to build a snapshot of phase space. This is one of the strengths of the method, as tracking for relatively few turns relaxes the precision to which input machine parameters need to be known. The recent addition of longitudinal space charge considerations as an optional refinement of the code is described. Simplicity suggested an approach based on the derivative of bunch shape with the properties of the vacuum chamber parametrized by a single value of distributed reactive impedance and by a geometrical coupling coefficient. This is sufficient to model the dominant collective effects in machines of low to moderate energy. In contrast to simulation codes, binning is not an issue since the profiles to be differentiated are measured ones. The program is written in Fortran 90 with High-Performance Fortran (HPF) extensions for parallel processing. A major effort has been made to identify and remove execution bottlenecks, for example by reducing floating-point calculations and re-coding slow intrinsic functions. A pointer-like mechanism which avoids the problems associated with pointers and parallel processing has been implemented. This is required to handle the large, sparse matrices that the algorithm employs. Results obtained with and without the inclusion of space charge are presented and compared for proton beams in the CERN PS Booster. Comparisons of

  13. Elevated Serum Ferritin Level Is Associated with the Incident Type 2 Diabetes in Healthy Korean Men: A 4 Year Longitudinal Study

    OpenAIRE

    Chang Hee Jung; Min Jung Lee; Jenie Yoonoo Hwang; Jung Eun Jang; Jaechan Leem; Joong-Yeol Park; JungBok Lee; Hong-Kyu Kim; Woo Je Lee

    2013-01-01

    BACKGROUND: Elevated ferritin concentration has been implicated in the etiology of type 2 diabetes. Accumulating evidence, mostly from studies conducted on western populations, has demonstrated a strong association between the elevated ferritin concentrations and incident type 2 diabetes. In Asian populations, however, the longitudinal studies investigating the association of elevated serum ferritin levels and type 2 diabetes are lacking. In present study, we aimed to determine whether elevat...

  14. Nationwide and population-based prescription patterns in bipolar disorder

    DEFF Research Database (Denmark)

    Kessing, Lars Vedel; Vradi, Eleni; Andersen, Per Kragh

    2016-01-01

    OBJECTIVES: The aim of the present study was to describe prescription patterns and changes in these patterns over the last decade for patients diagnosed with bipolar disorder in mental healthcare, using population-based and nationwide data, and to relate the findings to recommendations from...... international guidelines. METHODS: A population-based, nationwide study was carried out. It included register-based longitudinal data on all patients with a first-ever contact with mental healthcare with a diagnosis of mania/bipolar disorder from the entire Danish population, and all prescription data...

  15. Laser Wakefield diagnostic using holographic longitudinal interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Volfbeyn, P.; Esarey, E.; Leemans, W.P.

    1999-03-26

    We propose a diagnostic technique for wakefield measurement in plasma channels. A new technique for plasma channel creation, the Ignitor Heater scheme was proposed and experimentally tested in hydrogen and nitrogen previously. It makes use of two laser pulses. The Ignitor, an ultrashort (sub 100 fs) laser pulse, is brought to a line focus using a cylindrical lens to ionize the gas. The Heater pulse (160 ps long) is used to heat the existing spark via in-verse Bremsstrahlung. The hydrodynamic shock expansion creates a partially evacuated plasma channel with a density minimum on axis. Such a channel has properties of an optical waveguide. This technique allows creation of plasma channels in low atomic number gases, such as hydrogen, which is of importance for guiding of highly intense laser pulses. Laser pulses injected into such plasma channels produce a plasma wake that has a phase velocity close to the speed of light. A discussion of plasma wake measurements, using a Longitudinal Interferometry Wakefield Diagnostic Based on Time Domain Rayleigh Refractometry with Holographic Inversion, will be presented.

  16. Longitudinal variability of black carbon vertical profiles

    Science.gov (United States)

    Schwarz, J. P.; Weinzierl, B.; Samset, B. H.; Perring, A. E.; Dollner, M.; Heimerl, K.; Markovic, M. Z.; Ziemba, L. D.

    2015-12-01

    Black carbon (BC) aerosol contributes substantially to both climate forcing and climate forcing uncertainty. An important source of this uncertainty derives from the difficulty in predicting BC's global abundance and vertical distribution. Here we present a multi-year record of black carbon (BC) vertical concentration profiles from both sides of the Atlantic, obtained from airborne Single Particle Soot Photometers (SP2s) flown on the NASA DC-8, and the DLR Falcon research aircraft from the CONCERT, ACCESS, DC3, SEAC4RS, and SALTRACE campaigns. The measurements constrain the relative rates of BC transport/removal from, and zonal mixing in, the upper troposphere, as well as the range of BC loadings in these regions. They also constrain the time-rates of change of BC loads in altitudes at which it is a highly efficient (although sparse) climate forcer, and a relatively long-lived aerosol tracer. We find that concentration of BC in the upper troposphere can vary by a factor 10. Over the Northern mid-latitudes concentrations are however consistent to a fraction of this range over wide longitudinal ranges, over month-long timescales. The data show that BC becomes zonally mixed here starting at 500 hPa and extending to near the tropopause. These results imply broader value than previously associated with measured vertical profiles in constraining global scale BC loadings aloft.

  17. Longitudinal morphometric MRI study of Alzheimer's disease

    International Nuclear Information System (INIS)

    A longitudinal morphometric MRI study of Alzheimer's disease (AD) was conducted to determine the relationship between the progression of the symptoms and the progression of the brain atrophy. The Voxel-based Specific Regional Analysis System for Alzheimer's Disease (VSRAD), developed by Matsuda et al. was used as a method of morphometry to perform the statistical MR image analysis. Thirty-eight patients of AD patients were investigated with VSRAD. These patients were divided into two groups according to the progression of symptoms based on a clinical evaluation. One group was the progress group (20 patients), while the other group was the stable group (18 patients) for comparison. The relationship was investigated between the speed of the symptomatic progression and the change in each VSRAD indicator. Consequently, the entorhinal Z-score and the entorhinal atrophy rate showed a correlation with the speed of the symptomatic progression. The increase of the entorhinal Z-score in the follow-up was larger in the progress group than that in the stable group (0.65/1.28 years in the progress group and 0.05/1.26 years in the stable group.). These results suggest that a rapid symptomatic progression in an AD patient accompanies the rapid progression of atrophy in the entorhinal cortex. (author)

  18. A single hole tracer test to determine longitudinal dispersion

    International Nuclear Information System (INIS)

    The paper concerns a single hole tracer test to determine longitudinal dispersion, which is an important parameter in assessing the suitability of a site for radioactive waste disposal. The theory, equipment and procedure for measuring longitudinal dispersion in a single borehole is described. Results are presented for field trials conducted in an aquifer, where the technique produced good results. The measured value of longitudinal dispersion, from a single hole test, relates only to a limited volume of rock immediately adjacent to the borehole. (U.K.)

  19. A Semiparametric Marginalized Model for Longitudinal Data with Informative Dropout

    Directory of Open Access Journals (Sweden)

    Mengling Liu

    2012-01-01

    Full Text Available We propose a marginalized joint-modeling approach for marginal inference on the association between longitudinal responses and covariates when longitudinal measurements are subject to informative dropouts. The proposed model is motivated by the idea of linking longitudinal responses and dropout times by latent variables while focusing on marginal inferences. We develop a simple inference procedure based on a series of estimating equations, and the resulting estimators are consistent and asymptotically normal with a sandwich-type covariance matrix ready to be estimated by the usual plug-in rule. The performance of our approach is evaluated through simulations and illustrated with a renal disease data application.

  20. Tunable Single-Longitudinal-Mode High-Power Fiber Laser

    Directory of Open Access Journals (Sweden)

    Jonas K. Valiunas

    2012-01-01

    Full Text Available We report a novel CW tunable high-power single-longitudinal-mode fiber laser with a linewidth of ∼9 MHz. A tunable fiber Bragg grating provided wavelength selection over a 10 nm range. An all-fiber Fabry-Perot filter was used to increase the longitudinal mode spacing of the laser cavity. An unpumped polarization-maintaining erbium-doped fiber was used inside the cavity to eliminate mode hopping and increase stability. A maximum output power of 300 mW was produced while maintaining single-longitudinal-mode operation.

  1. A 16-year longitudinal study of hearing in very old Australians

    Directory of Open Access Journals (Sweden)

    L. Sanchez

    2011-03-01

    Full Text Available Hearing impairment is recognised for its prominence among the chronic conditions of ageing, being more prevalent in Australia than all other national health priorities except musculo-skeletal conditions (Australian Institute of Health and Welfare, 2004. However despite its prevalence, there have been fewer epidemiological studies of hearing impairment than for other chronic diseases and disorders. Epidemiological data based on audiological evaluations are scant and a rigorously defined burden of illness for hearing impairment at a population or community level using both audiological and self-report types of estimate is still only available from a few studies world-wide (Gates et al., 1990; Davis, 1995; Wilson et al., 1998; Cruikshanks et al., 1998. Longitudinal studies are particularly valuable in providing information about patterns of ageing, about cohort differences in age-related physical, sensory and psychological functioning and for the services which an ageing population might require...

  2. Development of a self-administered web-based test for longitudinal cognitive assessment

    Science.gov (United States)

    Ruano, Luis; Sousa, Andreia; Severo, Milton; Alves, Ivânia; Colunas, Márcio; Barreto, Rui; Mateus, Cátia; Moreira, Sandra; Conde, Eduardo; Bento, Virgílio; Lunet, Nuno; Pais, Joana; Tedim Cruz, Vítor

    2016-01-01

    Sequential testing with brief cognitive tools has been recommended to improve cognitive screening and monitoring, however the few available tools still depend on an external evaluator and periodic visits. We developed a self-administered computerized test intended for longitudinal cognitive testing (Brain on Track). The test can be performed from a home computer and is composed of several subtests, expected to evaluate different cognitive domains, all including random elements to minimize learning effects. An initial (A) and a refined version of the test (B) were applied to patients with mild cognitive impairment or early dementia (n = 88) and age and education-matched controls. A subsample of a population-based cohort (n = 113) performed the test at home every three months to evaluate test-retest reliability. The test’s final version Cronbach’s alpha was 0.90, test scores were significantly different between patients and controls (p = 0.001), the area under the receiver operating characteristic curve was 0.75 and the smallest real difference (43.04) was lower than the clinical relevant difference (56.82). In the test-retest reliability analysis 9/10 subtests showed two-way mixed single intraclass consistency correlation coefficient >0.70. These results imply good internal consistency, discriminative ability and reliability when performed at home, encouraging further longitudinal clinical and population-based studies. PMID:26743329

  3. Prenatal exposure to bereavement and type-2 diabetes: a Danish longitudinal population based study.

    Directory of Open Access Journals (Sweden)

    Jasveer Virk

    Full Text Available BACKGROUND: The etiology of type-2 diabetes is only partly known, and a possible role of prenatal stress in programming offspring for insulin resistance has been suggested by animal models. Previously, we found an association between prenatal stress and type-1 diabetes. Here we examine the association between prenatal exposure to maternal bereavement during preconception and pregnancy and development of type-2 diabetes in the off-spring. METHODS: We utilized data from the Danish Civil Registration System to identify singleton births in Denmark born January 1(st 1979 through December 31(st 2008 (N = 1,878,246, and linked them to their parents, grandparents, and siblings. We categorized children as exposed to bereavement during prenatal life if their mothers lost an elder child, husband or parent during the period from one year before conception to the child's birth. We identified 45,302 children exposed to maternal bereavement; the remaining children were included in the unexposed cohort. The outcome of interest was diagnosis of type-2 diabetes. We estimated incidence rate ratios (IRRs from birth using log-linear poisson regression models and used person-years as the offset variable. All models were adjusted for maternal residence, income, education, marital status, sibling order, calendar year, sex, and parents' history of diabetes at the time of pregnancy. RESULTS: We found children exposed to bereavement during their prenatal life were more likely to have a type-2 diabetes diagnosis later in life (aIRR: 1.31, 1.01-1.69. These findings were most pronounced when bereavement was caused by death of an elder child (aIRR: 1.51, 0.94-2.44. Results also indicated the second trimester of pregnancy to be the most sensitive period of bereavement exposure (aIRR:2.08, 1.15-3.76. CONCLUSIONS: Our data suggests that fetal exposure to maternal bereavement during preconception and the prenatal period may increase the risk for developing type-2 diabetes in childhood and young adulthood.

  4. Intergenerational Transmission of Child Problem Behaviors: A Longitudinal, Population-Based Study

    Science.gov (United States)

    van Meurs, Inge; Reef, Joni; Verhulst, Frank C.; van der Ende, Jan

    2009-01-01

    The scores of 4- to 16-year-olds on a child behavior checklist made in 1983 is compared with those of their 6- to 18-year-old offsprings that were done in 2007. It is found that most forms of problem behavior in children were predicted by their parent's behavior as children and that continuity is stronger in mothers than fathers and in sons than…

  5. Sleep disorders and demand for medical services: evidence from a population-based longitudinal study.

    Directory of Open Access Journals (Sweden)

    Rogerio Santos-Silva

    Full Text Available BACKGROUND: The aim of this study was to investigate whether insomnia and obstructive sleep apnea (OSA were predictors of hospitalizations or emergency department visits during two years following the Sao Paulo Epidemiologic Sleep Study (EPISONO sample. METHODS AND FINDINGS: All participants (n = 1,101 who underwent a baseline evaluation between July and December 2007 were contacted in December 2009 and asked to fill out a questionnaire about body weight changes, number of hospitalizations and visits to the emergency department. Participants lost during the follow-up period represented 3.2% (n = 35 and 7 subjects had died. Hospitalizations were reported by 116 volunteers (10.5% and emergency department visits were reported by 136 participants (12.4%. The average body mass index (BMI did not vary significantly between the first and the second assessment [26.7(95%CI:26.3-27.1 vs. 26.9(26.5-27.4 kg/m2]. After adjusting for confounders, a multiple logistic regression model revealed that female gender [1.4(1.0-1.9], age ≥ 40 years, insomnia diagnosed according to the DSM-IV criteria [1.6(1.0-2.6], and apnea-hypopnea index ≥ 15 [1.5(1.0-2.2] were predictors of hospitalizations and/or demand for emergency services. CONCLUSION: Our study of a probabilistic sample of the Sao Paulo inhabitants shows that over a period of two years, insomnia and OSA were both associated with health impairment. Considering the high prevalence and public health burden of sleep disorders, the consequences of untreated disease for both the individual and society are undeniable and should be addressed.

  6. The Association between Intelligence and Telomere Length : A Longitudinal Population Based Study

    NARCIS (Netherlands)

    Kingma, Eva M.; de Jonge, Peter; van der Harst, Pim; Ormel, Johan; Rosmalen, Judith G. M.

    2012-01-01

    Low intelligence has been associated with poor health and mortality, but underlying mechanisms remain obscure. We hypothesized that low intelligence is associated with accelerated biological ageing as reflected by telomere length; we suggested potential mediation of this association by unhealthy beh

  7. Gastrointestinal symptoms related to the irritable bowel syndrome - a longitudinal population-based register study

    DEFF Research Database (Denmark)

    Poulsen, Chalotte Heinsvig; Eplov, Lene Falgaard; Hjorthoj, Carsten;

    2016-01-01

    significant interactions between symptom groups and coexisting symptoms in relation to the two outcomes. Conclusions GI diseases were seen more frequently, but IBS was not associated with severe GI diseases or increased mortality. Clinicians should be more aware when patients do not fulfil the IBS definition......Objective Functional gastrointestinal (GI) symptoms can develop into persistent states often categorised as the irritable bowel syndrome (IBS). In the severe end of the GI symptom continuum, other coexisting symptoms are common. We aimed to investigate the GI symptom continuum in relation......-based IBS definition. The pooled cohort (n = 7278) was followed until December 2013 in Central Registries. Results Fifty-one percent had no GI symptoms, 39% had GI symptoms but never fulfilled the IBS definition, 8% had fluctuating IBS and 2% had persisting IBS. There was no significant association between...

  8. Increased prevalence of eosinophilia in a hemodialysis population: Longitudinal and case control studies.

    Science.gov (United States)

    Hildebrand, Sarah; Corbett, Richard; Duncan, Neill; Ashby, Damien

    2016-07-01

    Eosinophilia is commonly found in patients with clinical reactions to the hemodialysis circuit. With modern membranes, such reactions have become less common, but they may be under diagnosed in patients with subtle symptoms, in whom the presence of eosinophilia is an important diagnostic feature. Two case reports are presented, along with a hemodialysis study of the frequency and clinical associations of eosinophilia. In three hemodialysis facilities, all current hemodialysis patients with persistent eosinophilia (greater than 1 × 10(9) /L for 3 months) were identified. Control patients without eosinophilia (less than 0.5 × 10(9) /L for 3 months) matched for age, gender, and ethnicity were identified from the same facilities. A historical cohort of patients, dialyzing at the same facilities 5 years ago, was screened for the presence of persistent eosinophilia. From 510 patients, 24 cases of persistent eosinophilia were identified (4.7%). The median eosinophil count was 1.75 × 10(9) /L (range 1.1-7.5 × 10(9) /L). The prevalence in a historical cohort 5 years previously was significantly less at 1.5% (P = 0.046). Compared to controls, patients with eosinophilia were more likely to be on an angiotensin converting enzyme inhibitor (41.7% vs. 12.5%, P = 0.049), had a lower C-reactive protein (10 vs. 24 mg/L, P = 0.02) and were more likely to be using a fistula for access (P = 0.049). Over the following 12 months, there was no difference in the mean number of hospital admission days between cases and controls (7.6 vs. 11.5 days, P = 0.54), and no difference in mortality over 29 months (25.0% vs. 29.2%, P = 1.00). Eosinophilia remains not uncommon in hemodialysis patients, and in most cases reflects allergy to components of the dialysis circuit, which is usually subclinical. The overall prognosis for asymptomatic patients appears to be favourable.

  9. The Ethics of Organizations: A Longitudinal Study of the U.S. Working Population

    NARCIS (Netherlands)

    S.P. Kaptein (Muel)

    2009-01-01

    textabstractThe ethics of organizations has received much attention in recent years. This raises the question whether the ethics of organizations has also improved. In 1999, 2004 and 2008, a survey was conducted of 12,196 U.S. managers and employees. The results show that the ethical culture of orga

  10. Social class, social mobility and risk of psychiatric disorder--a population-based longitudinal study.

    Directory of Open Access Journals (Sweden)

    Sanna Tiikkaja

    Full Text Available OBJECTIVES: This study explored how adult social class and social mobility between parental and own adult social class is related to psychiatric disorder. MATERIAL AND METHODS: In this prospective cohort study, over 1 million employed Swedes born in 1949-1959 were included. Information on parental class (1960 and own mid-life social class (1980 and 1990 was retrieved from the censuses and categorised as High Non-manual, Low Non-manual, High Manual, Low Manual and Self-employed. After identifying adult class, individuals were followed for psychiatric disorder by first admission of schizophrenia, alcoholism and drug dependency, affective psychosis and neurosis or personality disorder (N=24,659 from the Swedish Patient Register. We used Poisson regression analysis to estimate first admission rates of psychiatric disorder per 100,000 person-years and relative risks (RR by adult social class (treated as a time-varying covariate. The RRs of psychiatric disorder among the Non-manual and Manual classes were also estimated by magnitude of social mobility. RESULTS: The rate of psychiatric disorder was significantly higher among individuals belonging to the Low manual class as compared with the High Non-manual class. Compared to High Non-manual class, the risk for psychiatric disorder ranged from 2.07 (Low Manual class to 1.38 (Low Non-manual class. Parental class had a minor impact on these estimates. Among the Non-manual and Manual classes, downward mobility was associated with increased risk and upward mobility with decreased risk of psychiatric disorder. In addition, downward mobility was inversely associated with the magnitude of social mobility, independent of parental class. CONCLUSIONS: Independently of parental social class, the risk of psychiatric disorder increases with increased downward social mobility and decreases with increased upward mobility.

  11. Social Class, Social Mobility and Risk of Psychiatric Disorder - A Population-Based Longitudinal Study

    Science.gov (United States)

    Tiikkaja, Sanna; Sandin, Sven; Malki, Ninoa; Modin, Bitte; Sparén, Pär; Hultman, Christina M.

    2013-01-01

    Objectives This study explored how adult social class and social mobility between parental and own adult social class is related to psychiatric disorder. Material and Methods In this prospective cohort study, over 1 million employed Swedes born in 1949-1959 were included. Information on parental class (1960) and own mid-life social class (1980 and 1990) was retrieved from the censuses and categorised as High Non-manual, Low Non-manual, High Manual, Low Manual and Self-employed. After identifying adult class, individuals were followed for psychiatric disorder by first admission of schizophrenia, alcoholism and drug dependency, affective psychosis and neurosis or personality disorder (N=24 659) from the Swedish Patient Register. We used Poisson regression analysis to estimate first admission rates of psychiatric disorder per 100 000 person-years and relative risks (RR) by adult social class (treated as a time-varying covariate). The RRs of psychiatric disorder among the Non-manual and Manual classes were also estimated by magnitude of social mobility. Results The rate of psychiatric disorder was significantly higher among individuals belonging to the Low manual class as compared with the High Non-manual class. Compared to High Non-manual class, the risk for psychiatric disorder ranged from 2.07 (Low Manual class) to 1.38 (Low Non-manual class). Parental class had a minor impact on these estimates. Among the Non-manual and Manual classes, downward mobility was associated with increased risk and upward mobility with decreased risk of psychiatric disorder. In addition, downward mobility was inversely associated with the magnitude of social mobility, independent of parental class. Conclusions Independently of parental social class, the risk of psychiatric disorder increases with increased downward social mobility and decreases with increased upward mobility. PMID:24260104

  12. Multivariate longitudinal data analysis with mixed effects hidden Markov models.

    Science.gov (United States)

    Raffa, Jesse D; Dubin, Joel A

    2015-09-01

    Multiple longitudinal responses are often collected as a means to capture relevant features of the true outcome of interest, which is often hidden and not directly measurable. We outline an approach which models these multivariate longitudinal responses as generated from a hidden disease process. We propose a class of models which uses a hidden Markov model with separate but correlated random effects between multiple longitudinal responses. This approach was motivated by a smoking cessation clinical trial, where a bivariate longitudinal response involving both a continuous and a binomial response was collected for each participant to monitor smoking behavior. A Bayesian method using Markov chain Monte Carlo is used. Comparison of separate univariate response models to the bivariate response models was undertaken. Our methods are demonstrated on the smoking cessation clinical trial dataset, and properties of our approach are examined through extensive simulation studies. PMID:25761965

  13. Variable selection and estimation for longitudinal survey data

    KAUST Repository

    Wang, Li

    2014-09-01

    There is wide interest in studying longitudinal surveys where sample subjects are observed successively over time. Longitudinal surveys have been used in many areas today, for example, in the health and social sciences, to explore relationships or to identify significant variables in regression settings. This paper develops a general strategy for the model selection problem in longitudinal sample surveys. A survey weighted penalized estimating equation approach is proposed to select significant variables and estimate the coefficients simultaneously. The proposed estimators are design consistent and perform as well as the oracle procedure when the correct submodel was known. The estimating function bootstrap is applied to obtain the standard errors of the estimated parameters with good accuracy. A fast and efficient variable selection algorithm is developed to identify significant variables for complex longitudinal survey data. Simulated examples are illustrated to show the usefulness of the proposed methodology under various model settings and sampling designs. © 2014 Elsevier Inc.

  14. Longitudinal Statistics for New Social Security Disability Insurance Beneficiaries.

    OpenAIRE

    David Stapleton; Su Liu; Dawn Phelps; Sarah Prenovitz

    2010-01-01

    This paper presents the findings from a longitudinal examination regarding the extent to which new Social Security Disability Insurance beneficiaries return to work and use disability insurance work incentives, based on Social Security Administration data.

  15. Nonlinear correction to the longitudinal structure function at small x

    Energy Technology Data Exchange (ETDEWEB)

    Boroun, G.R. [Razi University, Physics Department, Kermanshah (Iran)

    2010-03-15

    We computed the longitudinal proton structure function F{sub L}, using the nonlinear Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (NLDGLAP) evolution equation approach at small x. For the gluon distribution, the nonlinear effects are related to the longitudinal structure function. As the very small-x behavior of the gluon distribution is obtained by solving the Gribov, Levin, Ryskin, Mueller and Qiu (GLR-MQ) evolution equation with the nonlinear shadowing term incorporated, we show that the strong rise that corresponds to the linear QCD evolution equations can be tamed by screening effects. Consequently, the obtained longitudinal structure function shows a tamed growth at small x. We computed the predictions for all details of the nonlinear longitudinal structure function in the kinematic range where it has been measured by the H1 Collaboration and made comparisons with the computation by Moch, Vermaseren and Vogt at the second order with input data from the MRST QCD fit. (orig.)

  16. Longitudinal Vibrations of Rheological Rod With Variable Cross Section

    Institute of Scientific and Technical Information of China (English)

    Katica(Stevanovic)HEDRIH; AleksandarFILIPOVSKI

    1999-01-01

    Longitudinal vibrations of rheological rod with variable cross section are examined.Particular solutions and eigenfunction are accomplished for natural vibrations of the rod with hereditary material of standard hereditary body.Some examples are given.

  17. Un análisis transversal y longitudinal en el estado de pobreza en Alemania = A cross-sectional and longitudinal analysis of poverty in Germany

    Directory of Open Access Journals (Sweden)

    González Rodríguez, María Rosario

    2007-01-01

    Full Text Available El objetivo del trabajo se centra en un análisis transversal y longitudinal de la pobreza en Alemania en el período de 1985 a 1996, utilizando la base de datos Panel Comparability Project. El análisis transversal nos permite conocer cómo el proceso de reunificación alemana influye en el nivel de pobreza y en la intensidad de la misma. Por su parte, el análisis longitudinal nos permite seguir a los individuos en el tiempo, posibilitando la observación de los períodos en el estado de pobreza, la transición al estado de no pobreza, así como la longitud de su permanencia por debajo del umbral de pobreza. Dado que los datos contienen información de características individuales y del hogar, un análisis basado en las estimaciones de la función riesgo y de supervivencia hace posible la identificación de aquellas características socioeconómicas más destacables de la población que son propias de la pobreza permanente y transitoria. = The objective of this research focuses on both a cross-sectional and longitudinal analyses of poverty in Germany from 1986 to 1996, using the Panel Comparability Project data set. On the one hand, the cross-sectional analysis allows us to know how the Reunification Process influences on the level and the intensity of poverty. On the other hand, the longitudinal analysis allows us to follow up the individuals in time, and therefore to observe the permanence in poverty, and the transition out of poverty. Since the data set contains information about household and individual characteristics, an analysis based on the estimations of the risk and survival function makes possible the identification of those socioeconomic characteristics of the population which are more proper of the permanent and transitory poverty.

  18. Transverse and longitudinal angular momenta of light

    International Nuclear Information System (INIS)

    We review basic physics and novel types of optical angular momentum. We start with a theoretical overview of momentum and angular momentum properties of generic optical fields, and discuss methods for their experimental measurements. In particular, we describe the well-known longitudinal (i.e., aligned with the mean momentum) spin and orbital angular momenta in polarized vortex beams. Then, we focus on the transverse (i.e., orthogonal to the mean momentum) spin and orbital angular momenta, which were recently actively discussed in theory and observed in experiments. First, the recently-discovered transverse spin  angular momenta appear in various structured fields: evanescent waves, interference fields, and focused beams. We show that there are several kinds of transverse spin angular momentum, which differ strongly in their origins and physical properties. We describe extraordinary features of the transverse optical spins and overview recent experiments. In particular, the helicity-independent transverse spin inherent in edge evanescent waves offers robust spin–direction coupling at optical interfaces (the quantum spin Hall effect of light). Second, we overview the transverse orbital angular momenta of light, which can be both extrinsic and intrinsic. These two types of the transverse orbital angular momentum are produced by spatial shifts of the optical beams (e.g., in the spin Hall effect of light) and their Lorentz boosts, respectively. Our review is underpinned by a unified theory of the angular momentum of light based on the canonical momentum and spin densities, which avoids complications associated with the separation of spin and orbital angular momenta in the Poynting picture. It allows us to construct a comprehensive classification of all known optical angular momenta based on their key parameters and main physical properties

  19. BENDING-SHEAR INTERACTION OF LONGITUDINALLY STIFFENED GIRDERS

    OpenAIRE

    Beg, Darko; Sinur, Franc

    2011-01-01

    To understand behaviour of longitudinally stiffened plated girders subjected to high bending moments and shear forces, four tests on large scale test specimens were performed. The results of these tests were used to verify the numerical model, which was employed for further parametric studies. With a verified simplified numerical model a parametric nonlinear analysis was systematically carried out to determine the resistance of longitudinally stiffened plated girders. Based on 630 numerical s...

  20. Variable Selection for Marginal Longitudinal Generalized Linear Models

    OpenAIRE

    Eva Cantoni; Joanna Mills Flemming; Elvezio Ronchetti

    2003-01-01

    Variable selection is an essential part of any statistical analysis and yet has been somewhat neglected in the context of longitudinal data analysis. In this paper we propose a generalized version of Mallows's Cp (GCp) suitable for use with both parametric and nonparametric models. GCp provides an estimate of a measure of model's adequacy for prediction. We examine its performance with popular marginal longitudinal models (fitted using GEE) and contrast results with what is typically done in ...

  1. Longitudinal control laws design for a flying wing aircraft

    OpenAIRE

    Zhu, Yan

    2012-01-01

    This research is concerned with the flight dynamic, pitch flight control and flying qualities assessment for the reference BWB aircraft. It aims to develop the longitudinal control laws which could satisfy the flying and handing qualities over the whole flight envelope with added consideration of centre of gravity (CG) variation. In order to achieve this goal, both the longitudinal stability augmentation system (SAS) and autopilot control laws are studied in this thesis. Usi...

  2. Gender differences in postpartum depression. A longitudinal cohort study

    OpenAIRE

    Escribà-Agüir, Vicenta; Artazcoz, Lucía

    2010-01-01

    Abstract Background: The course of depression from pregnancy to one year postpartum and their risk factors among mothers and fathers are not known. This study has two aims: 1) To report the longitudinal patterns of depression from third trimester of pregnancy to one year after childbirth and 2) to determine gender differences between women and their partners in the effect of psychosocial and personal factors on postpartum depression. Methods: A longitudinal cohort study was carr...

  3. Longitudinal Statistics for New Supplemental Security Income Beneficiaries

    OpenAIRE

    Yonatan Ben-Shalom; David Stapleton; Dawn Phelps; Maura Bardos

    2012-01-01

    Using Social Security Administration data, this paper presents findings from a longitudinal analysis of the extent to which new Supplemental Security Income (SSI) disability beneficiaries return to work and use SSI work incentives. Longitudinal statistics show that more than 8 percent of those first awarded SSI benefits as adults in 2001 had their benefits suspended due to work for at least a month by December 2007.

  4. Impedance Analysis of Longitudinal Bunch Shape Measurements at PLS

    CERN Document Server

    Hwang, Ilmoon; Kim Eun San; Yoon, Moohyun

    2005-01-01

    We measured the longitudinal bunch shape by streak camera at 2.5 GeV Pohang Light Source. The impedances estimated by a series R+L model indicate a resistance R= 960 ohm, an inductance L= 80 nH and a longitudinal impedance Z/n= 0.53 ohm. The scaling law for the bunch lengthenig is expressed as I0

  5. Longitudinal Stability Criteria for a Propeller-Driven Aircraft

    OpenAIRE

    Gil Iosilevskii

    2010-01-01

    The Routh criterion is used to assess longitudinal dynamic stability of a propeller-driven aircraft. Under a few plausible assumptions on possible ranges of the pertinent stability derivatives, it reduces to a pair of simple conditions imposing a traditional aft limit (the forward of the maneuver and the neutral-speed-stability points) on the center-of-gravity position and an upper limit on the longitudinal moment of inertia. It is demonstrated that most aircraft have sufficiently small inert...

  6. Distribution of Longitudinal Inherent Strains in Multiple-passes Welding

    Institute of Scientific and Technical Information of China (English)

    Peng HE; Jiuhai ZHANG; Toshio Terasaki; Testuya Akiyama

    2001-01-01

    A fundamental theory for the analysis of residual welding stresses and deformation based on the inherent strain distribution along the welded joint is introduced. The computing method of distribution of longitudinal inherent strains in multiple-passes welding in heavy plate weldment is proposed. Distribution of longitudinal inherent strains in one-pass welding and two-passes welding are compared and analyzed. The effect of cutting on inherent strain is discussed.

  7. Transverse Mode Formation in Longitudinally Pumped Miniature Slab Lasers

    Institute of Scientific and Technical Information of China (English)

    XU Jian-Qiu; YE Xin; FANG Tao

    2006-01-01

    The formation of transverse modes in longitudinally pumped miniature slab lasers is investigated theoretically and experimentally. The longitudinally non-uniform gain-guiding is studied by expanding the electric field into the Hermite-Gaussian functions that satisfy boundary conditions of the resonator. Non-Gaussian transversal beam profiles in the near field are found and the beam diameter is reduced when the pump spot becomes smaller. The experimental observation agrees with the theoretical calculation.

  8. Spatial variation of the longitudinal dispersion coefficient in an estuary

    OpenAIRE

    D. C. Shaha; Y.-K. Cho; M.-T. Kwak; S. R. Kundu; K. T. Jung

    2011-01-01

    The effective longitudinal dispersion is a primary tool for determining property distributions in estuaries. Most previous studies have examined the longitudinal dispersion coefficient for the average tidal condition. However, information on spatial and temporal variations of this coefficient at low and high tide is scarce. Three years of hydrographic data taken at low and high tide along the main axis of the Sumjin River Estuary (SRE), Korea are used to estimate the spatial and temporal vari...

  9. Participation in an Intensive Longitudinal Study with Weekly Web Surveys Over 2.5 Years

    Science.gov (United States)

    Barber, Jennifer; Kusunoki, Yasamin; Schulz, Paul

    2016-01-01

    Background Technological advances have made it easier for researchers to collect more frequent longitudinal data from survey respondents via personal computers, smartphones, and other mobile devices. Although technology has led to an increase in data-intensive longitudinal studies, little is known about attrition from such studies or the differences between respondents who complete frequently administered surveys in a timely manner, and respondents who do not. Objective We examined respondent characteristics and behaviors associated with continued and on-time participation in a population-based intensive longitudinal study, using weekly web-based survey interviews over an extended period. Methods We analyzed data from the Relationship Dynamics and Social Life study, an intensive longitudinal study that collected weekly web-based survey interviews for 2.5 years from 1003 18- and 19-year-olds to investigate factors shaping the dynamics of their sexual behavior, contraceptive use, and pregnancies. Results Ordinary least squares and logistic regression analyses showed background respondent characteristics measured at baseline were associated with the number of days respondents remained enrolled in the study, the number of interviews they completed, and the odds that they were late completing interviews. In addition, we found that changes in pregnancy-related behaviors reported in the weekly interviews were associated with late completion of interviews. Specifically, after controlling for sociodemographic, personality, contact information, and prior experience variables, we found that weekly reports such as starting to have sex (odds ratio [OR] 1.17, 95% CI 1.03-1.32, P=.01), getting a new partner (OR 1.76, 95% CI 1.53-2.03, P<.001), stopping the use of contraception (OR 1.28, 95% CI 1.10-1.49, P=.001), and having a new pregnancy (OR 5.57, 95% CI 4.26-7.29, P<.001) were significantly associated with late survey completion. However, young women who reported changes in

  10. Food-Insecure Dietary Patterns Are Associated With Poor Longitudinal Glycemic Control in Diabetes: Results From the Boston Puerto Rican Health Study

    OpenAIRE

    Berkowitz, Seth A; Gao, Xiang; Tucker, Katherine L.

    2014-01-01

    OBJECTIVE To determine whether dietary patterns associated with food insecurity are associated with poor longitudinal glycemic control. RESEARCH DESIGN AND METHODS In a prospective, population-based, longitudinal cohort study, we ascertained food security (Food Security Survey Module), dietary pattern (Healthy Eating Index–2005 [HEI 2005]), and hemoglobin A1c (HbA1c) in Puerto Rican adults aged 45–75 years with diabetes at baseline (2004–2009) and HbA1c at ∼2 years follow-up (2006–2012). We d...

  11. Association between population prevalence of smoking and incidence of meningococcal disease in Norway, Sweden, Denmark and the Netherlands between 1975 and 2009

    DEFF Research Database (Denmark)

    Norheim, Gunnstein; Sadarangani, Manish; Omar, Omar;

    2014-01-01

    OBJECTIVE: To investigate the relationship between the prevalence of smoking in the population and incidence of invasive meningococcal disease (IMD) among children under 5 years of age. DESIGN: Retrospective, longitudinal, observational study. Poisson regression controlled for confounding factors...

  12. An investigation into student understanding of longitudinal standing waves

    Science.gov (United States)

    Dostal, Jack Alan

    This study investigates the difficulties that introductory university physics students have with the concept of longitudinal standing waves in the context of standing waves in pipes. My goal is to identify difficulties that persist even after standard instruction on longitudinal standing waves and attempt to improve upon that method of instruction. The study follows a four-step design. I first use exploratory surveys and interviews with students to elicit the difficulties present in students' understanding of longitudinal standing waves in pipes. I then use the information gained to create and assessment instrument, the Standing Waves Diagnostic Test, and a curricular intervention, the Longitudinal Standing Waves Tutorial. I then undertake a three-step process of pre-testing students with the Standing Wave Diagnostic Test, intervention with the Longitudinal Standing Waves Tutorial, and post-testing again with the Standing Wave Diagnostic Test to determine the impact of the intervention. This is then compared to data from students in classes where the intervention is not used. Students using the intervention significantly outperform their non-intervention counterparts on the Standing Wave Diagnostic Test. The results of the students pre- and post-tests indicate that significant improvement in students' understandings of longitudinal standing waves can be achieved by the use of the tutorial.

  13. Longitudinal changes in white matter microstructure after heavy cannabis use.

    Science.gov (United States)

    Becker, Mary P; Collins, Paul F; Lim, Kelvin O; Muetzel, R L; Luciana, M

    2015-12-01

    Diffusion tensor imaging (DTI) studies of cannabis users report alterations in brain white matter microstructure, primarily based on cross-sectional research, and etiology of the alterations remains unclear. We report findings from longitudinal voxelwise analyses of DTI data collected at baseline and at a 2-year follow-up on 23 young adult (18-20 years old at baseline) regular cannabis users and 23 age-, sex-, and IQ-matched non-using controls with limited substance use histories. Onset of cannabis use was prior to age 17. Cannabis users displayed reduced longitudinal growth in fractional anisotropy in the central and parietal regions of the right and left superior longitudinal fasciculus, in white matter adjacent to the left superior frontal gyrus, in the left corticospinal tract, and in the right anterior thalamic radiation lateral to the genu of the corpus callosum, along with less longitudinal reduction of radial diffusion in the right central/posterior superior longitudinal fasciculus, corticospinal tract, and posterior cingulum. Greater amounts of cannabis use were correlated with reduced longitudinal growth in FA as was relatively impaired performance on a measure of verbal learning. These findings suggest that continued heavy cannabis use during adolescence and young adulthood alters ongoing development of white matter microstructure, contributing to functional impairment.

  14. Challenges in Cluster Analyses for Longitudinal Data

    OpenAIRE

    Bruckers, Liesbeth

    2014-01-01

    In this dissertation, we have addressed clustering for high dimensional data, possibly subject to missingness. The research was inspired by a number of data sets, ranging from data collected in a mental care setting, studies in patients with abdominal aortic aneurysm or heart failure, to an EEG study in rats. The communality in these studies is the believe that the population under investigation is not homogenous, but instead consists of subpopulations. A direct labelling of these subpopulati...

  15. LONGITUDINAL STUDIES OF MUSICALLY GIFTED SCHOOLGIRLS

    Directory of Open Access Journals (Sweden)

    Svetlana N. Loseva

    2016-01-01

    Full Text Available The aim of the article is to consider the empirical aspects of the development of musical gifted schoolgirls in vocal and choral activities.Methods. Scientific methods of research (observation, questionnaire, interview, formative experiment, longitude, testing are used. Data are analyzed using a complex of psychodiagnostic techniques: culture and free intelligence test by R. Cattell; the modified creative test by F. Williams; personal multifactorial questionnaire by R. Cattell. The reliability of the results and the validity of the findings is provided by the use of reliable and proven in the domestic and foreign psychology methods and techniques, using different statistical methods of data processing, the definition of parametric and non-parametric statistical tests (Student’s t-criterion, Spearman’s rank correlation, criterion U-Mann – Whitney, criterion T-Wilcoxon, L-criterion trends Page.Results and scientific novelty. Results of longitudinal research of development of musical aptitude are presented. Experimental work in which schoolgirls of 8–15 years participated, was carried out on the basis of creative choral collectives of Irkutsk within three years. Features of development of the pupils who are engaged in singing are revealed. It is established that in process of development of specially developed program (comprehension of emotional and semantic aspects of perception of a piece of music, finding of ability to distinguish musical timbres and the general coloring of sounding etc. analytical and intonation hearing improves under pupils’ age. Regular long singing trainings promote formation of cogitative operations: active development of divergent, rational and logical thinking and intelligence in general, and also acquisition of skills of a self-assessment. Besides, such occupations dispose children and teenagers to emotional responsiveness and spiritual self-improvement.Practical significance. The research

  16. A comparison of statistical methods for the discovery of genetic risk factors using longitudinal family study designs

    Directory of Open Access Journals (Sweden)

    Kelly M Burkett

    2015-11-01

    Full Text Available The etiology of immune-related diseases or traits is often complex, involving many genetic and environmental factors and their interactions. While methodological approaches focusing on an outcome measured at one time point have succeeded in identifying genetic factors involved in immune-related traits, they fail to capture complex disease mechanisms that fluctuate over time. It is increasingly recognized that longitudinal studies, where an outcome is measured at multiple time points, have great potential to shed light on complex disease mechanisms involving genetic factors. However, longitudinal data requires specialized statistical methods, especially in family studies where multiple sources of correlation in the data must be modeled. Using simulated data with known genetic effects, we examined the performance of different analytical methods for investigating associations between genetic factors and longitudinal phenotypes in twin data. The simulations were modeled on data from the Québec Newborn Twin Study, an ongoing population-based longitudinal study of twin births with multiple phenotypes, such as cortisol levels and body mass index, collected multiple times in infancy and early childhood and with sequencing data on immune-related genes and pathways. We compared approaches that we classify as (1 family-based methods applied to summaries of the observations over time, (2 longitudinal-based methods with simplifications of the familial correlation and (3 Bayesian family-based method with simplifications of the temporal correlation. We found that for estimation of the genetic main and interaction effects, all methods gave estimates close to the true values and had similar power. If heritability estimation is desired, approaches of type (1 also provide heritability estimates close to the true value. Our work shows that the simpler approaches are likely adequate to detect genetic effects; however, interpretation of these effects is more

  17. Three Essays on the Well-Being of Vulnerable Populations.

    OpenAIRE

    Mykerezi, Elton

    2007-01-01

    ABSTRACT This dissertation is composed of three essays that measure the impact of social programs and policies on the well being of their target populations. The first essay entitled "The Wage Impact of Historically Black College and University Attendance" examines the impact of attending a Historically Black College or University on the wages of Blacks attending HBCUs versus other four year colleges or universities using a sample of Blacks from the National Longitudinal Survey of Youth (...

  18. Dogslife: A web-based longitudinal study of Labrador Retriever health in the UK

    Directory of Open Access Journals (Sweden)

    Clements Dylan N

    2013-01-01

    Full Text Available Abstract Background Dogslife is the first large-scale internet-based longitudinal study of canine health. The study has been designed to examine how environmental and genetic factors influence the health and development of a birth cohort of UK-based pedigree Labrador Retrievers. Results In the first 12 months of the study 1,407 Kennel Club (KC registered eligible dogs were recruited, at a mean age of 119 days of age (SD 69 days, range 3 days – 504 days. Recruitment rates varied depending upon the study team’s ability to contact owners. Where owners authorised the provision of contact details 8.4% of dogs were recruited compared to 1.3% where no direct contact was possible. The proportion of dogs recruited was higher for owners who transferred the registration of their puppy from the breeder to themselves with the KC, and for owners who were sent an e-mail or postcard requesting participation in the project. Compliance with monthly updates was highly variable. For the 280 dogs that were aged 400 days or more on the 30th June 2011, we estimated between 39% and 45% of owners were still actively involved in the project. Initial evaluation suggests that the cohort is representative of the general population of the KC registered Labrador Retrievers eligible to enrol with the project. Clinical signs of illnesses were reported in 44.3% of Labrador Retrievers registered with Dogslife (median age of first illness 138 days, although only 44.1% of these resulted in a veterinary presentation (median age 316 days. Conclusions The web-based platform has enabled the recruitment of a representative population of KC registered Labrador Retrievers, providing the first large-scale longitudinal population-based study of dog health. The use of multiple different methods (e-mail, post and telephone of contact with dog owners was essential to maximise recruitment and retention of the cohort.

  19. Education Vital Signs: Population.

    Science.gov (United States)

    Zakariya, Sally Banks

    1985-01-01

    Population changes and demographics shape the future of public schools. Includes statistics on ethnic makeup of student population, the projected baby boomlet, children of working mothers, households without children, and the aging population. (MD)

  20. Simulating Population Growth.

    Science.gov (United States)

    Byington, Scott

    1997-01-01

    Presents a strategy to help students grasp the important implications of population growth. Involves an interactive demonstration that allows students to experience exponential and logistic population growth followed by a discussion of the implications of population-growth principles. (JRH)

  1. Longitudinal study of urban malaria in a cohort of Ugandan children: description of study site, census and recruitment

    Directory of Open Access Journals (Sweden)

    Staedke Sarah G

    2006-03-01

    Full Text Available Abstract Background Studies of malaria in well-defined cohorts offer important data about the epidemiology of this complex disease, but few have been done in urban African populations. To generate a sampling frame for a longitudinal study of malaria incidence and treatment in Kampala, Uganda, a census, mapping and survey project was conducted. Methods All households in a geographically defined area were enumerated and mapped. Probability sampling was used to recruit a representative sample of children and collect baseline descriptive data for future longitudinal studies. Results 16,172 residents living in 4931 households in a densely-populated community (18,824 persons/km2 were enumerated. A total of 582 households were approached with at least one child less than 10 years of age in order to recruit 601 children living in 322 households. At enrollment, 19% were parasitaemic, 24% were anaemic, 43% used bednets, and 6% used insecticide-treated nets. Low G6PD activity (OR = 0.33, P = 0.009 and bednet use (OR = 0.64, P = 0.045 were associated with a decreased risk of parasitaemia. Increasing age (OR = 0.62 for each year, P Conclusion Detailed surveys of target populations in urban Africa can provide valuable descriptive data and provide a sampling frame for recruitment of representative cohorts for longitudinal studies. Plans to use a multi-disciplinary approach to improve the understanding of the distribution and determinants of malaria incidence and response to therapy in this population are discussed.

  2. A dynamic population-based model for the development of work-related respiratory health effects among bakery workers.

    NARCIS (Netherlands)

    Warren, N.; Meijster, T.; Heederik, D.; Tielemans, E.

    2009-01-01

    OBJECTIVES: This paper presents a dynamic population-based model for the development of sensitisation and respiratory symptoms in bakery workers. The model simulates a population of individual workers longitudinally and tracks the development of work-related sensitisation and respiratory symptoms in

  3. A dynamic population-based model for the development of work-related respiratory health effects among bakery workers

    NARCIS (Netherlands)

    Warren, N.; Meijster, T.; Heederik, D.; Tielemans, E.

    2009-01-01

    Objectives: This paper presents a dynamic population-based model for the development of sensitisation and respiratory symptoms in bakery workers. The model simulates a population of individual workers longitudinally and tracks the development of work-related sensitisation and respiratory symptoms in

  4. Active recruitment and limited participant-load related to high participation in large population-based biobank studies

    NARCIS (Netherlands)

    van Zon, Sander K R; Scholtens, Salome; Reijneveld, Sijmen A; Smidt, Nynke; Bültmann, Ute

    2016-01-01

    OBJECTIVE: Insight into baseline participation rates and their determinants is crucial for designing future population-based biobank studies. We therefore conducted a systematic review and meta-analysis of baseline participation rates and their determinants in large longitudinal population-based bio

  5. Computer simulation model for the striped bass young-of-the-year population in the Hudson River. [Effects of entrainment and impingement at power plants on population dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Eraslan, A.H.; Van Winkle, W.; Sharp, R.D.; Christensen, S.W.; Goodyear, C.P.; Rush, R.M.; Fulkerson, W.

    1975-09-01

    This report presents a daily transient (tidal-averaged), longitudinally one-dimensional (cross-section-averaged) computer simulation model for the assessment of the entrainment and impingement impacts of power plant operations on young-of-the-year populations of the striped bass, Morone saxatilis, in the Hudson River.

  6. Association between leukocyte and metabolic syndrome in urban Han Chinese: a longitudinal cohort study.

    Directory of Open Access Journals (Sweden)

    Wenjia Meng

    Full Text Available BACKGROUND: Although cross-sectional studies have shown that leukocyte is linked with metabolic syndrome (MetS, few longitudinal or cohort studies have been used to confirm this relationship. We therefore conducted a large-scale health check-up longitudinal cohort in urban Chinese population from middle to upper socioeconomic strata to investigate and prove the association between the total leukocyte/its subtypes and MetS/its components (obesity, hyperglycemia, dyslipidemia, and hypertension. METHODS: A longitudinal cohort study was established in 2005 on individuals who were middle-to-upper class urban Chinese. Data used in this investigation was based on 6,513 participants who had at least three routine health check-ups over a period of six-year follow-up. Data analysis was conducted through generalized estimating equation (GEE model. RESULTS: A total of 255 cases of MetS occurred over the six-year follow-up, leading to a total incidence density of 11.45 per 1,000 person-years (255/22279 person-years. The total leukocyte was markedly associated with MetS (RR = 2.66, 95%CI = 1.81-3.90], p<0.0001 and a dose-response existed. Similar trends can be found in monocytes, lymphocytes, and neutrophils compared with the total leukocyte. The total leukocyte, neutrophil, monocyte and eosinophil levels were strong and independent risk factors to obesity, total leukocyte and neutrophil to dyslipidemia and hyperglycemia, while neither total leukocyte nor its subtypes to hypertension. CONCLUSION: Total leukocyte/its subtype were associated with MetS/its components (obesity, dyslipidemia and hyperglycemia, they might provide convenient and useful markers for further risk appraisal of MetS, and be the earlier biomarkers for predicting cardiovascular disease than the components of MetS.

  7. Physical Activity, Blood Glucose and C-Peptide in Healthy School-Children, a Longitudinal Study.

    Directory of Open Access Journals (Sweden)

    Karina Huus

    Full Text Available To further elucidate the relationship between physical activity and several risk factors for development of diabetes (glucose, C-peptide and obesity over time.A prospective longitudinal study where physical activity was measured on 199 children from Kalmar and Linköping at age 8, and the same 107 children from Linköping again at age 12. Anthropometric data was collected and blood was analyzed for C-peptide and f-glucose. The children in the study were representative for the general Swedish child population, and on an average lean.High physical activity was related to lower C-peptide at age 8 and 12. This correlation was especially pronounced in boys, who also were more physically active than girls at both time points. The association seen at 8 years of age was similar at age 12 in most children. Children with higher BMI Z-Score had a higher fasting C-peptide (age 12 but linear regression showed that children with more steps per day were less likely to have a higher fasting C-peptide irrespective of BMI. Longitudinal follow-up showed that a decrease in physical activity increased insulin resistance and β-cell load.Already in young children, physical activity improves insulin sensitivity and decreases the need of C-peptide over time. This seems to become even more pronounced with increasing age when children are followed longitudinally. Low physical activity increases the load on insulin producing β-cells, might increase the risk for both type 1- and 2 diabetes.

  8. Social Integration and Maternal Smoking: A Longitudinal Analysis of a National Birth Cohort.

    Science.gov (United States)

    Mumford, Elizabeth A; Liu, Weiwei

    2016-08-01

    Objectives Social support and engagement are related to smoking behavior in general populations, but it is unknown whether these measures of social integration as experienced by recent mothers are related to longitudinal maternal smoking patterns. The purpose of this study is, first, to describe longitudinal patterns of maternal smoking before, during, and after pregnancy through the early childhood parenting years, as well as variation in these patterns; and second, to examine these patterns in relation to social integration, emotional, behavioral, and sociodemographic factors. Methods Among 9050 mothers of the Early Childhood Longitudinal Study-Birth Cohort (a nationally representative probability sample of children born in 2001), we estimated trajectories of maternal smoking with a general growth mixture model and examined how baseline predictors are associated with these patterns over a 5-6 year period beginning 3 months prior to pregnancy. Results A 5-class solution identified trajectories of nonsmokers (70.5 %), temporary quitters (9.4 %), pregnancy-inspired quitters (3.3 %), delayed initiators (5.1 %), and persistent smokers (11.7 %). Modifiable risk factors included postpartum alcohol consumption and behavioral cues from co-resident smokers, while breastfeeding beyond 6 months and social engagement through religious service attendance were protective characteristics. Conclusions for Practice Prevention of and treatment for maternal perinatal and postpartum smoking is best informed by mothers' emotional, behavioral and sociodemographic characteristics. Religious service attendance, but not measures of social support or social engagement, was a protective factor for maternal smoking trajectories. PMID:26987858

  9. Nonsuicidal self-injury in adolescence: longitudinal course, trajectories, and intrapersonal predictors.

    Science.gov (United States)

    Barrocas, Andrea L; Giletta, Matteo; Hankin, Benjamin L; Prinstein, Mitchell J; Abela, John R Z

    2015-02-01

    Although prevalence rates of nonsuicidal self-injury (NSSI) has been established throughout adolescence, little is known about the progression of NSSI, and consequently, about the risk factors for youth NSSI engagement. This study aimed to describe the overall longitudinal course of NSSI and the latent trajectory classes of NSSI in a population-based sample of adolescents using multi-wave data. Moreover, this study examined whether sex, lifetime history of depression, rumination, and negative attributional style predicted the longitudinal course of NSSI and trajectory group membership. Participants were 617 Chinese adolescents in Grades 10 through 12 (51.4 % girls). NSSI was assessed across eight waves of data. History of depression, rumination, and negative attributional style were assessed at baseline. Latent growth curve modeling revealed that only lifetime depression predicted the longitudinal course of NSSI from Grades 10 to 12, with depressed adolescents showing greater and more stable NSSI engagement over time than non-depressed adolescents. Group-based trajectory modeling yielded three distinct trajectory classes of NSSI engagement: low (69.2 %), moderate (26.1 %), and chronic (4.7 %). Negative attributional style distinguished adolescents in the chronic vs. low and moderate NSSI trajectory classes. Sex, rumination, and lifetime depression predicted membership in the chronic and/or moderate vs. low NSSI trajectory class. NSSI trajectory classes, based on frequency of NSSI, exist and are differentiated by sex, depression history, rumination, and negative attributional style. This study suggests that during this period of adolescence NSSI may be a relatively stable behavior, especially for some adolescents. Negative attributional style may be a salient risk factor for chronic NSSI engagement.

  10. Longitudinal mode structure in a non-planar ring resonator

    Directory of Open Access Journals (Sweden)

    M Jaberi

    2013-09-01

    Full Text Available  The structure of longitudinal modes of a passively Q-switched, non-planar unidirectional ring-resonator,with Nd:YAG active medium is described in this article. Two different techniques are used to study the longitudinal mode structure of the laser resonator. At first, the fast-fourier transform technique is applied for analyzing the mode beating of the optical fields by intensity frequency structure of the laser pulses to determine the number of longitudinal modes. Then, an analyzer etalon is used to observe Fabry-Perot fringes to compute the numbers of the resonator longitudinal modes. The results of two techniques are in good agreement with each other. Under the proper conditions, a reliable single longitudinal mode of the non-planar ring-resonator can be achieved with a good spatial mode profile that originates from the unidirectional travelling optical field propagation in the resonator having a very low sensitivity of the non-planar ring resonator to the optical elements misalignment.

  11. Relationships between longitudinal and radial Picea genera sound vibration parameters

    Institute of Scientific and Technical Information of China (English)

    SHEN Jun

    2006-01-01

    Longitudinal sawn wood are usually selected as samples in the study of sound properties of a musical instrument board.But in real production,radial sawn timber are cut and are also widely used as vibration component.Therefore,it is very important to evaluate the vibration properties of the board in the round,especially for the sound radiation characteristic of radial sawn timber and its relationship to longitudinal sawn timber.However,for the national and international experts,researches on radial sawn timber and its role and function in sound emission have not yet been developed.This paper describes a study of seven important spruces that grow up in the Sichuan and Heilongjiang provinces of China,and one Picea sitchensis specimen from North America.Under the high bending vibration mode,resonance frequency and other parameters of longitudinal and radial wood were tested.Analysis result disclosed the relationship between longitudinal and radial wood vibration property.An important conclusion of wood for musical instruments with proper anisotropy,fine toughness,and weak shear of longitudinal and radial vibration was inducted.

  12. Social Determinants, Race, and Brain Health Outcomes: Findings from the Chicago Health and Aging Project.

    Science.gov (United States)

    Aggarwal, Neelum T; Everson-Rose, Susan A; Evans, Denis A

    2015-01-01

    The broad spectrum of economic and cultural diversity in the U.S. population correlates with and affects the study of behavioral aspects of health. The purpose of this article is to provide a selective overview of research findings from the Chicago Health and Aging Project (CHAP), which covers a socio-demographically diverse population in Chicago, with a focus on role-related psychosocial factors and observed racial/ethnic differences in aging outcomes. CHAP is a longitudinal, epidemiological study of common chronic conditions of aging with an emphasis on medical, psychosocial, and environmental risk factors for the decline in cognitive function across the older adult lifespan. We briefly summarize the study design and methods used in the CHAP study and characterize the study population and describe the psychosocial data, noting black-white associations as they relate to three common brain health outcomes: cognitive function and Alzheimer's Disease, stroke, and subclinical vascular disease as noted on neuroimaging. PMID:26239039

  13. Longitudinal associations between lifestyle and vitamin D

    DEFF Research Database (Denmark)

    Skaaby, Tea; Husemoen, Lise Lotte Nystrup; Thuesen, Betina Heinsbæk;

    2016-01-01

    Several lifestyle factors have been found to be associated with vitamin D status in cross-sectional studies, but it is not clear whether a change in these factors can actually affect the vitamin D level. We investigated the association between repeated measurements of physical activity, body mass...... index (BMI), diet, alcohol consumption, and smoking habits, and corresponding levels of vitamin D during 5 years of follow-up of a large general population sample. We included 4185 persons who participated and had vitamin D (serum-25-hydroxyvitamin D, 25-OH-D) measurements in the Inter99 study...... at baseline (1999-2001) and 5-year follow-up. In a subsample, 25-OH-D was also measured at 1- and 3-year follow-ups. We used mixed models to examine the association between repeated measurements of lifestyle factors and 25-OH-D levels. In multivariable analyses of repeated measurements, the difference in 25...

  14. A learner developed longitudinal interprofessional education curriculum.

    Science.gov (United States)

    Fitzsimmons, Amber; Cisneros, Breanne; Samore, Jennifer

    2014-01-01

    Increased patient safety requires interprofessional collaboration, now critical given rising healthcare costs and an aging population with complex and chronic conditions. One way in which to educate future health care team members about team dynamics is to have them learn through active participation on a team. Six students representing the five health professions programs at the University of California, San Francisco formed a curriculum development team that created a novel yearlong interprofessional education curriculum and assessed its impact on knowledge, skills and attitudes of first-year learners in medicine, physical therapy, dentistry, nursing, and pharmacy (n = 480). Through their participation on the curriculum development team and reflection on their roles, responsibilities, communication and negotiation, the six students developed the inter-personal and intra-personal skills required for successful interprofessional collaboration.

  15. Estimating Population Dynamics without Population Data

    OpenAIRE

    Robert Chambers; Vangelis Tzouvelekas

    2012-01-01

    We develop a biologically correct cost system for production systems facing invasive pests that allows the estimation of population dynamics without a priori knowledge of their true values. We apply that model to a data set for olive producers in Crete and derive from it predictions about the underlying populations dynamics. Those dynamics are compared to information on population dynamics obtained from pest sampling with extremely favorable results.

  16. Effects of deployment on mental health in modern military forces: A review of longitudinal studies

    Directory of Open Access Journals (Sweden)

    Peter Nasveld

    2012-08-01

    Full Text Available Background. Earlier studies presenting evidence that operational deployment negatively affects mental health outcomes among military personnel and veterans generally have lacked conclusiveness, largely because of cross-sectional or retrospective design. Purpose. To review longitudinal studies investigating mental health outcomes of military personnel deployed in recent conflicts. Methods. MEDLINE database was searched using relevant keywords and MESH terms. The US Millennium Cohort study website was used to obtain the list of relevant publications. Only prospective longitudinal cohort studies investigating mental health outcomes in deployed post Vietnam era military or veteran populations of developed countries were included. Results. Eighteen studies fulfilled the inclusion criteria. Adverse effects included the increased incidence of post-deployment PTSD and depression. Individuals with the lowest functional scores and those exposed to previous traumatic assault were particularly vulnerable to a new onset of PTSD after combat exposure. Factors influencing the incidence of post-deployment PTSD included depression symptoms present during deployment, the presence of stress reaction during combat exposure and reception of associated frontline treatment, and the number of negative life events experienced after the traumatic event. More mental health problems were reported in soldiers returning from Iraq on the second screening conducted several months after their return, compared with the first screening immediately upon their return. Some mental health symptoms (anxiety and depression improved between deployments, while others (PTSD and panic attacks did not improve. CONCLUSION. The results indicate that combat exposure, not deployment in general , had an adverse effect on mental health.

  17. Loss and gain cycles? A longitudinal study about burnout, engagement and self-efficacy

    Directory of Open Access Journals (Sweden)

    Susana Llorens-Gumbau

    2014-06-01

    Full Text Available The present longitudinal study (two waves, conducted on a population of 274 secondary-school teachers, expands on previous research on burnout and work engagement. Accordingly, the effect of organizational factors (obstacles, facilitators as well as personal resources (self-efficacy on burnout and engagement is tested longitudinally following the Social Cognitive Theory. More specifically, we test the loss and gain cycles, and reciprocal relationships concerning burnout, engagement, and self-efficacy over time. Four questions are addressed: (1 Are obstacles positively related to burnout and work self-efficacy over time? (2 Are facilitators positively related to engagement and self-efficacy over time? (3 Is work self-efficacy negatively related to burnout and obstacles over time? and (4 Is work self-efficacy positively related to engagement and facilitators over time? The results of a hard-copy survey carried out at two waves (8 months between the two times, which were computed on Structural Equation Modeling show that obstacles are positively related to burnout, which in turn is positively related to self-efficacy over time. Likewise, facilitators are positively related to engagement and self-efficacy, which in turn is positively related to facilitators over time. These findings suggest a positive gain cycle in which self-efficacy plays a central role.

  18. Longitudinal change detection in diffusion MRI using multivariate statistical testing on tensors.

    Science.gov (United States)

    Grigis, Antoine; Noblet, Vincent; Heitz, Fabrice; Blanc, Frédéric; de Sèze, Jérome; Kremer, Stéphane; Rumbach, Lucien; Armspach, Jean-Paul

    2012-05-01

    This paper presents a longitudinal change detection framework for detecting relevant modifications in diffusion MRI, with application to neuromyelitis optica (NMO) and multiple sclerosis (MS). The core problem is to identify image regions that are significantly different between two scans. The proposed method is based on multivariate statistical testing which was initially introduced for tensor population comparison. We use this method in the context of longitudinal change detection by considering several strategies to build sets of tensors characterizing the variability of each voxel. These strategies make use of the variability existing in the diffusion weighted images (thanks to a bootstrap procedure), or in the spatial neighborhood of the considered voxel, or a combination of both. Results on synthetic evolutions and on real data are presented. Interestingly, experiments on NMO patients highlight the ability of the proposed approach to detect changes in the normal-appearing white matter (according to conventional MRI) that are related with physical status outcome. Experiments on MS patients highlight the ability of the proposed approach to detect changes in evolving and non-evolving lesions (according to conventional MRI). These findings might open promising prospects for the follow-up of NMO and MS pathologies. PMID:22387171

  19. The Cognitive Processes underlying Affective Decision-making Predicting Adolescent Smoking Behaviors in a Longitudinal Study

    Directory of Open Access Journals (Sweden)

    Lin eXiao

    2013-10-01

    Full Text Available This study investigates the relationship between three different cognitive processes underlying the Iowa Gambling Task (IGT and adolescent smoking behaviors in a longitudinal study. We conducted a longitudinal study of 181 Chinese adolescents in Chengdu City, China. The participants were followed from 10th grade to 11th grade. When they were in the 10th grade (Time 1, we tested these adolescents’ decision-making using the Iowa Gambling Task and working memory capacity using the Self-ordered Pointing Test (SOPT. Self-report questionnaires were used to assess school academic performance and smoking behaviors. The same questionnaires were completed again at the one-year follow-up (Time 2. The Expectancy-Valence (EV Model was applied to distill the IGT performance into three different underlying psychological components: (i a motivational component which indicates the subjective weight the adolescents assign to gains versus losses; (ii a learning-rate component which indicates the sensitivity to recent outcomes versus past experiences; and (iii a response component which indicates how consistent the adolescents are between learning and responding. The subjective weight to gains vs. losses at Time 1 significantly predicted current smokers and current smoking levels at Time 2, controlling for demographic variables and baseline smoking behaviors. Therefore, by decomposing the IGT into three different psychological components, we found that the motivational process of weight gain vs. losses may serve as a neuropsychological marker to predict adolescent smoking behaviors in a general youth population.

  20. The parent–child relationship and adolescent alcohol use: a systematic review of longitudinal studies

    Directory of Open Access Journals (Sweden)

    Visser Leenke

    2012-10-01

    Full Text Available Abstract Background Alcohol use among adolescents has become a major public health problem in the past decade and has large short- and long-term consequences on their health. The aim of this systematic review was to provide an overview of longitudinal cohort studies that have analyzed the association between the parent–child relationship (PCR and change in alcohol use during adolescence. Methods A search of the literature from 1985 to July 2011 was conducted in Medline, PsycINFO, and EMBASE in order to identify longitudinal, general population studies regarding the influence of the PCR on alcohol use during adolescence. The studies were screened, and the quality of the relevant studies was assessed. A best-evidence synthesis was used to summarize the results. Results Twenty-eight relevant studies were identified. Five studies found that a negative PCR was associated with higher levels of alcohol use. Another seven papers only found this association for certain subgroups such as boys or girls, or a specific age group. The remaining sixteen studies did not find any association. Conclusions We found weak evidence for a prospective association between the PCR and adolescent alcohol use. Further research to the association of the PCR with several types of alcohol use (e.g., initiation or abuse and to the potential reversed causality of the PCR and alcohol use is required.

  1. Describing the longitudinal course of major depression using Markov models: Data integration across three national surveys

    Directory of Open Access Journals (Sweden)

    Lee Robert C

    2005-11-01

    Full Text Available Abstract Background Most epidemiological studies of major depression report period prevalence estimates. These are of limited utility in characterizing the longitudinal epidemiology of this condition. Markov models provide a methodological framework for increasing the utility of epidemiological data. Markov models relating incidence and recovery to major depression prevalence have been described in a series of prior papers. In this paper, the models are extended to describe the longitudinal course of the disorder. Methods Data from three national surveys conducted by the Canadian national statistical agency (Statistics Canada were used in this analysis. These data were integrated using a Markov model. Incidence, recurrence and recovery were represented as weekly transition probabilities. Model parameters were calibrated to the survey estimates. Results The population was divided into three categories: low, moderate and high recurrence groups. The size of each category was approximated using lifetime data from a study using the WHO Mental Health Composite International Diagnostic Interview (WMH-CIDI. Consistent with previous work, transition probabilities reflecting recovery were high in the initial weeks of the episodes, and declined by a fixed proportion with each passing week. Conclusion Markov models provide a framework for integrating psychiatric epidemiological data. Previous studies have illustrated the utility of Markov models for decomposing prevalence into its various determinants: incidence, recovery and mortality. This study extends the Markov approach by distinguishing several recurrence categories.

  2. Longitudinal jitter analysis of linear accelerator electron gun

    CERN Document Server

    Mingshan, Liu; Iqbal, Munawar

    2015-01-01

    We present measurement and analyses of longitudinal timing jitter of Beijing Electron Positron Collider (BEPCII) linear accelerator electron gun. We simulated longitudinal jitter effect of the gun using PARMELA about beam performance including beam profile, average energy, energy spread, longitudinal phase of reference particle and XY emittance. The maximum percentage difference of the beam parameters are calculated to be; 100%, 13.27%, 42.24%, 7.79% and 65.01%, 86.81%, respectively due to which the bunching efficiency is reduced to 54%. The simulation results are in agreement with test and are helpful to optimize the beam parameters by tuning the trigger timing of the gun during the bunching process.

  3. Longitudinal ridging test for ACR-1000® fuel sheathing

    Energy Technology Data Exchange (ETDEWEB)

    Bates, M.; Abbas, S.A.; Chakraborty, K.; Wang, X.; Xu, Z. [Atomic Energy of Canada Limited, Mississauga, Ontario (Canada)

    2010-07-01

    CANDU® fuel uses thin wall sheathing to reduce neutron absorption, enhance uranium utilization and provide excellent heat transfer between the sheathing and the UO{sub 2} pellets. A large diametral clearance between the fuel pellets and the sheath can result in severe longitudinal ridging under reactor operating conditions. The Advanced CANDU Reactor(ACR-1000®) fuel will also adopt thin wall sheathing. Since the ACR-1000 reference fuel element dimensions and the primary heat transport operating parameters are different compared to the CANDU-6, out-reactor tests were performed for ACR-1000 fuel covering the applicable range of parameters that have an impact on longitudinal ridge formation. This paper presents the range of parameters tested and the test method developed, which are used in predicting critical collapse pressures for longitudinal ridge formation of fuel elements with dimensions spanning both of the ACR-1000 fuel element types. The results from this testing are discussed. (author)

  4. Stellar longitudinal magnetic field determination through multi-Zeeman signatures

    CERN Document Server

    Vélez, J C Ramírez; Navarro, S G; Córdova, J P; Sabin, L; Ruelas-Mayorga, A

    2016-01-01

    Context. A lot of effort has been put into the detection and determination of stellar magnetic fields using the spectral signal obtained from the combination of hundreds or thousands of individual lines, an approach known as multi-line techniques. However, so far most of multi-line techniques developed that retrieve stellar mean longitudinal magnetic fields recourse to sometimes heavy simplifications concerning line shapes and Zeeman splittings. Aims. To determine stellar longitudinal magnetic fields by means of the Principal Components Analysis and Zeeman Doppler Imaging (PCA-ZDI) multi-line technique, based on accurate polarised spectral line synthesis. Methods. In this paper we present the methodology to perform inversions of profiles obtained with PCA-ZDI. Results. Inversions with various magnetic geometries, field strengths and rotational velocities show that we can correctly determine the effective longitudinal magnetic field in stars using the PCA-ZDI method.

  5. Longitudinal intensity effects in the CERN Large Hadron Collider

    CERN Document Server

    AUTHOR|(CDS)2081238; Rivkin, Leonid

    This PhD thesis provides an improved knowledge of the LHC longitudinal impedance model and a better understanding of the longitudinal intensity effects. These effects can limit the LHC performance and lead to a reduction of the integrated luminosity. The LHC longitudinal impedance was measured with beams. Results obtained using traditional techniques are consistent with the expectations based on the impedance model, although the measurement precision was proven insufficient for the low impedance of the LHC. Innovative methods to probe the LHC reactive impedance were successfully used. One of the methods is based on exciting the beam with a sinusoidal rf phase modulation to estimate the synchrotron frequency shift from potential-well distortion. In the second method, the impedance is estimated from the loss of Landau damping threshold, which is also found to be in good agreement with analytical estimations. Beam-based impedance measurements agree well with estimations using the LHC impedance model. Macropartic...

  6. Statistical methods for longitudinal data with agricultural applications

    DEFF Research Database (Denmark)

    Anantharama Ankinakatte, Smitha

    The PhD study focuses on modeling two kings of longitudinal data arising in agricultural applications: continuous time series data and discrete longitudinal data. Firstly, two statistical methods, neural networks and generalized additive models, are applied to predict masistis using multivariate...... continuous time series data obtained from robotic milking of cows, and their performance is compared. Secondly, the use of acyclic probabilistic finite automata /APFA) to model univariate discret longitudinal data is studied from a statistical modeling perspective, leading to a modified model selection...... algorithm. This was found to compare favourably with the algorithm implemented in the well-known Beagle software. Finally, an R package to apply APFA models developed as part of the PhD project is described...

  7. Longitudinal beam dynamics for heavy ion fusion using WARPrz

    International Nuclear Information System (INIS)

    WARPrz is a 2.5 dimensional, cylindrically symmetric, electrostatic, particle-in-cell code. It is part of the WARP family of codes which has been developed to study heavy ion fusion driver issues. WARPrz is being used to study the longitudinal dynamics of heavy ion beams including a longitudinal instability that is driven by the impedance of the LINAC accelerating modules. This instability is of concern because it can enhance longitudinal momentum spread; chromatic abhoration in the lens system restricts the amount of momentum spread allowed in the beam in the final focusing system. The impedance of the modules is modeled by a continuum of resistors and capacitors in parallel in WARPrz. We discuss simulations of this instability including the effect of finite temperature and reflection of perturbations off the beam ends. We also discuss intermittency of axial confining fields (''ears'' fields) as a seed for this instability

  8. Single Bunch Longitudinal Instability in the CERN SPS

    CERN Document Server

    Lasheen, Alexandre; Hancock, Steven; Radvilas, Edgaras; Roggen, Toon; Shaposhnikova, Elena

    2016-01-01

    The longitudinal single bunch instability observed in the SPS leads to uncontrolled emittance blow-up and limits the quality of high intensity beams required for the High Luminosity LHC and AWAKE projects at CERN. The present SPS impedance model developed from a thorough survey of machine elements was used in macro-particle simulations (with the code BLonD) of the bunch behavior through the acceleration cycle. Comparison of simulations with measurements of the synchrotron frequency shift, performed on the SPS flat bottom to probe the impedance, show a reasonable agreement. During extensive experimental studies various beam and machine parameters (bunch intensity, longitudinal emittance, RF voltage, with single and double RF systems) were scanned in order to further benchmark the SPS impedance model with measurements and to better understand the mechanism behind the instability. It was found that the dependence of instability threshold on longitudinal emittance and beam energy has an unexpected non-monotonic b...

  9. Longitudinal Magnetoresistance and "Chiral" Coupling in Silver Chalcogenides

    Institute of Scientific and Technical Information of China (English)

    XU Jie; ZHANG Duan-Ming

    2011-01-01

    A complex longitudinal magnetoresistance (MR∥) effect in the non-stoichiometric silver chalcogenides (include the silver selenide and telluride) has been found, however the mechanism for the MR∥ effect is not clear now.In this work, a new random resistor network for MR∥ effect is proposed based on the experimental observation. The network is constructed from six-terminal resistor units and the mobility of carries within the network has a Gaussian distribution. Considering the non-zero transverse-longitudinal coupling in materials, the resistance matrix of the sixterminal resistor unit is modified. It is found that the material has the "chiral" transverse-longitudinal couplings, which is suggested a main reason for the complex MR∥ effect. The model predictions are compared with the experimental results.A three dimension (3D) visualization of current flow within the network demonstrates the "current jets" phenomenon in the thickness of materials clearly.

  10. Longitudinal tire force estimation based on sliding mode observer

    Energy Technology Data Exchange (ETDEWEB)

    El Hadri, A.; Cadiou, J.C.; M' Sirdi, N.K. [Versailles Univ., Paris (France). Lab. de Robotique; Beurier, G.; Delanne, Y. [Lab. Central des Ponts, Centre de Nantes (France)

    2001-07-01

    This paper presents an estimation method for vehicle longitudinal dynamics, particularly the tractive/braking force. The estimation can be used to detect a critical driving situation to improve security. It can be used also in several vehicle control systems. The main characteristics of the vehicle longitudinal dynamics were taken into account in the model used to design an observer and computer simulations. The state variables are the angular wheel velocity, vehicle velocity and the longitudinal tire force. The proposed differential equation of the tractive/braking force is derived using the concept of relaxation length. The observer designed is based on the sliding mode approach using only the angular wheel velocity measurement. The proposed method of estimation is verified through a one-wheel simulation model with a ''Magic formula'' tire model. Simulations results show an excellent reconstruction of the tire force. (orig.)

  11. Human Population Problems

    Science.gov (United States)

    Emmel, Thomas C.; Sligh, Michael M.

    1970-01-01

    Asserts that overpopulation is the most pressing world problem. Topics discussed include population control in primitive societies, population growth and control in modern societies, methods of motivational population control, consequences of no population control, and mass famines during the 1970's in underdeveloped countries. Cities 33…

  12. Some Current Population Trends.

    Science.gov (United States)

    Taeuber, Conrad

    Population trends in the 1960's and early 1970's are examined in this 1972 speech in terms of overall national trends, the growth of metropolitan areas, the rural population, geographic shifts, internal migration, the black population, and living arrangements. It is noted that population growth in the 1960's was unevenly distributed within age…

  13. Decorrelation of anisotropic flow along the longitudinal direction

    Energy Technology Data Exchange (ETDEWEB)

    Pang, Long-Gang [Frankfurt Institute for Advanced Studies, Frankfurt am Main (Germany); Petersen, Hannah [Frankfurt Institute for Advanced Studies, Frankfurt am Main (Germany); Goethe University, Institute for Theoretical Physics, Frankfurt am Main (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Qin, Guang-You [Central China Normal University, Key Laboratory of Quark and Lepton Physics (MOE) and Institute of Particle Physics, Wuhan (China); Roy, Victor [Goethe University, Institute for Theoretical Physics, Frankfurt am Main (Germany); Wang, Xin-Nian [Central China Normal University, Key Laboratory of Quark and Lepton Physics (MOE) and Institute of Particle Physics, Wuhan (China); Lawrence Berkeley National Laboratory, Nuclear Science Division MS70R0319, Berkeley, CA (United States)

    2016-04-15

    The initial energy density distribution and fluctuations in the transverse direction lead to anisotropic flow of final hadrons through collective expansion in high-energy heavy-ion collisions. Fluctuations along the longitudinal direction, on the other hand, can result in decorrelation of anisotropic flow in different regions of pseudorapidity (η). Decorrelation of the 2nd- and 3rd-order anisotropic flow with different η gaps for final charged hadrons in high-energy heavy-ion collisions is studied in an event-by-event (3+1)D ideal hydrodynamic model with fully fluctuating initial conditions from A Multi-Phase Transport (AMPT) model. The decorrelation of anisotropic flow of final hadrons with large η gaps is found to originate from the spatial decorrelation along the longitudinal direction in the AMPT initial conditions through hydrodynamic evolution. The decorrelation is found to consist of both a linear twist and random fluctuation of the event plane angles. The agreement between our results and recent CMS data in most centralities suggests that the string-like mechanism of initial parton production in AMPT model captures the initial longitudinal fluctuation that is responsible for the measured decorrelation of anisotropic flow in Pb+Pb collisions at LHC. Our predictions for Au+Au collisions at the highest RHIC energy show stronger longitudinal decorrelation, indicating larger longitudinal fluctuations at lower beam energies. Our study also calls into question some of the current experimental methods for measuring anisotropic flow and the quantitative extraction of transport coefficients through comparisons to hydrodynamic simulations that do not include longitudinal fluctuations. (orig.)

  14. Decorrelation of anisotropic flow along the longitudinal direction

    Science.gov (United States)

    Pang, Long-Gang; Petersen, Hannah; Qin, Guang-You; Roy, Victor; Wang, Xin-Nian

    2016-04-01

    The initial energy density distribution and fluctuations in the transverse direction lead to anisotropic flow of final hadrons through collective expansion in high-energy heavy-ion collisions. Fluctuations along the longitudinal direction, on the other hand, can result in decorrelation of anisotropic flow in different regions of pseudorapidity ( η . Decorrelation of the 2nd- and 3rd-order anisotropic flow with different η gaps for final charged hadrons in high-energy heavy-ion collisions is studied in an event-by-event (3+1)D ideal hydrodynamic model with fully fluctuating initial conditions from A Multi-Phase Transport (AMPT) model. The decorrelation of anisotropic flow of final hadrons with large η gaps is found to originate from the spatial decorrelation along the longitudinal direction in the AMPT initial conditions through hydrodynamic evolution. The decorrelation is found to consist of both a linear twist and random fluctuation of the event plane angles. The agreement between our results and recent CMS data in most centralities suggests that the string-like mechanism of initial parton production in AMPT model captures the initial longitudinal fluctuation that is responsible for the measured decorrelation of anisotropic flow in Pb+Pb collisions at LHC. Our predictions for Au+Au collisions at the highest RHIC energy show stronger longitudinal decorrelation, indicating larger longitudinal fluctuations at lower beam energies. Our study also calls into question some of the current experimental methods for measuring anisotropic flow and the quantitative extraction of transport coefficients through comparisons to hydrodynamic simulations that do not include longitudinal fluctuations.

  15. Analysis of repeated outcome measures from longitudinal studies

    Institute of Scientific and Technical Information of China (English)

    Yuanjia WANG; Naihua DUAN

    2011-01-01

    @@ In many clinical studies repeated measurements of an outcome are collected over time.For example,in an 8-week study of treatment for obsessive compulsive disorder,the severity of the disorder may be measured weekly using the Yale-Brown-Obsessive-Compulsive-Disorder-Scale (YBOCS).For each study participant who completes the study,there will be nine repeated measures of YBOCS (a baseline assessment plus eight assessments during the course of treatment).Such a study in which participants are followed and measured repeatedly over time is called a longitudinal study and the resulting data are called longitudinal data.

  16. Positive illusions in marital relationships: a 13-year longitudinal study.

    Science.gov (United States)

    Miller, Paul J E; Niehuis, Sylvia; Huston, Ted L

    2006-12-01

    This study examined the long-term consequences of idealization in marriage, using both daily diary and questionnaire data collected from a sample of 168 newlywed couples who participated in a 4-wave, 13-year longitudinal study of marriage. Idealization was operationalized as the tendency for people to perceive their partner as more agreeable than would be expected based on their reports of their partner's agreeable and disagreeable behaviors. Spouses who idealized one another were more in love with each other as newlyweds. Longitudinal analyses suggested that spouses were less likely to suffer declines in love when they idealized one another as newlyweds. Newlywed levels of idealization did not predict divorce.

  17. Retinoid-induced ossification of the posterior longitudinal ligament

    International Nuclear Information System (INIS)

    Vitamin A and its synthetic congeners are known to produce a variety of skeletal abnormalities in patients on prolonged treatment with these medications. Two patients are described who developed posterior longitudinal ligament ossification following treatment with the synthetic retinoid 13-cis-retinoic acid. In both cases, this finding became apparent after other retinoid-induced skeletal abnormalities were observed and was less marked than the ossification of the anterior longitudinal ligament. Although spinal cord compression did not occur in our patients, patients on long-term retinoid therapy should be carefully observed for this complication. (orig.)

  18. Longitudinal vector form factors in weak decays of nuclei

    CERN Document Server

    Simkovic, F; Krivoruchenko, M I

    2015-01-01

    The longitudinal form factors of the weak vector current of particles with spin $ J = 1/2 $ and isospin $ I = 1/2 $ are determined by the mass difference and the charge radii of members of the isotopic doublets. The most promising reactions to measure these form factors are the reactions with large momentum transfers involving the spin-1/2 isotopic doublets with a maximum mass splitting. Numerical estimates of longitudinal form factors are given for nucleons and eight nuclear spin-1/2 isotopic doublets.

  19. Intrapartum Diagnosis and Treatment of Longitudinal Vaginal Septum

    Directory of Open Access Journals (Sweden)

    Antonio Henriques de França Neto

    2014-01-01

    Full Text Available Longitudinal vaginal septum is a rare Müllerian malformation that may be associated with dyspareunia, dysmenorrhea, primary amenorrhea, and infertility. In this report, the authors present a case of longitudinal vaginal septum in a 15-year-old patient with a full-term pregnancy whose diagnosis was only made during labor following bidigital vaginal and speculum examination. Septoplasty was performed during the second stage of labor. Both mother and child progressed satisfactorily and were discharged from hospital in good health. Six months later, ultrasonography, hysterosalpingography, and hysteroscopy were carried out and no other associated abnormality was found.

  20. Longitudinal vector form factors in weak decays of nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Šimkovic, F. [Bogoliubov Laboratory of Theoretical Physics, JINR, 141980 Dubna (Russian Federation); Department of Nuclear Physics and Biophysics, Comenius University, Mlynská dolina F1 SK–842 48 Bratislava (Slovakia); Kovalenko, S. [Universidad Técnica Federico Santa Mariya, Centro-Cientifico-Tecnológico de Valparaiso, Casilla 110-V, Valparaiso (Chile); Krivoruchenko, M. I. [Bogoliubov Laboratory of Theoretical Physics, JINR, 141980 Dubna (Russian Federation); Institute for Theoretical and Experimental Physics, B. Cheremushkinskaya 25, 117218 Moscow (Russian Federation)

    2015-10-28

    The longitudinal form factors of the weak vector current of particles with spin J = 1/2 and isospin I = 1/2 are determined by the mass difference and the charge radii of members of the isotopic doublets. The most promising reactions to measure these form factors are the reactions with large momentum transfers involving the spin-1/2 isotopic doublets with a maximum mass splitting. Numerical estimates of longitudinal form factors are given for nucleons and eight nuclear spin-1/2 isotopic doublets.

  1. Longitudinal course of pharmacotherapy in obsessive-compulsive disorder

    DEFF Research Database (Denmark)

    Grant, Jon E; Mancebo, Maria C; Weinhandl, Eric;

    2013-01-01

    , medications, and dosage changes were obtained annually using the Longitudinal Interval Follow-up Evaluation. RESULTS: During the 5-year follow-up period, 151 patients had at least one trial of an SRI for 12 weeks or more. A total of 110 patients (43.7%) discontinued their medication (i.e. ceased taking...... cumulative incidence was 33.3%. Among patients with worsening of OCD upon SRI discontinuation, the median time to worsening was 39 weeks. CONCLUSION: This first longitudinal study on the use of SRIs in OCD found that patients who had achieved partial or full remission on SRIs were less likely to discontinue...

  2. ROBUST ESTIMATION IN PARTIAL LINEAR MIXED MODEL FOR LONGITUDINAL DATA

    Institute of Scientific and Technical Information of China (English)

    Qin Guoyou; Zhu Zhongyi

    2008-01-01

    In this article, robust generalized estimating equation for the analysis of par- tial linear mixed model for longitudinal data is used. The authors approximate the non- parametric function by a regression spline. Under some regular conditions, the asymptotic properties of the estimators are obtained. To avoid the computation of high-dimensional integral, a robust Monte Carlo Newton-Raphson algorithm is used. Some simulations are carried out to study the performance of the proposed robust estimators. In addition, the authors also study the robustness and the efficiency of the proposed estimators by simulation. Finally, two real longitudinal data sets are analyzed.

  3. A Longitudinal Study of Usability in Health Care

    DEFF Research Database (Denmark)

    Kjeldskov, Jesper; Skov, Mikael B.; Stage, Jan

    2010-01-01

    We report from a longitudinal laboratory-based usability evaluation of a health care information system. The purpose of the study was to inquire into the nature of usability problems experienced by novice and expert users, and to see to what extend usability problems of a health care information...... system may or may not disappear over time, as the nurses get more familiar with it-if time heals poor design? As our method for studying this, we conducted a longitudinal study with two key studies. A usability evaluation was conducted with novice users when an electronic patient record system was being...

  4. Frequency Dependence of Longitudinal Correlation Length in the Yellow Sea

    Institute of Scientific and Technical Information of China (English)

    LI Feng-Hua; ZHANG Ren-He

    2008-01-01

    Spatial correlation coefficient is one of the most important parameters for the description of sound propagation in shallow water. Frequency dependence of the longitudinal correlation length is still an open topic. We observe in a shallow water experiment that the longitudinal correlation length in units of wavelength increases with the increase of frequency. This phenomenon has not been seen in the published papers. The theoretical analysis and numerical simulations indicate that the non-linear frequency relationship of the bottom attenuation is the main cause of this phenomenon.

  5. Longitudinal and cross-sectional changes with age in selected anthropometric and physiological traits in hospitalized adults: an insight from the Polish Longitudinal Study of Aging (PLSA

    Directory of Open Access Journals (Sweden)

    Chmielewski Piotr

    2015-12-01

    Full Text Available Longitudinal studies of aging concerning individuals with comparable lifestyle, diet, health profile, socioeconomic status, and income remain extraordinarily rare. The purposes of our ongoing project are as follows: (i to collect extensive data on biological and medical aspects of aging in the Polish population, (ii to determine factors affecting the rate and course of aging, (iii to understand how aging unfolds as a dynamic and malleable process in ontogeny, and (iv to find novel predictors of longevity. Our investigation followed 142 physically healthy asylum inmates, including 68 males and 74 females, for at least 25 years from the age of 45 years onward. Cross-sectional assessment involved 225 inmates, including 113 males and 112 females. All the patients lived for a very long time under similar and good environmental conditions at the hospital in Cibórz, Lubuskie Province. They maintained virtually the same daily schedule and lifestyle. The rate and direction of changes with age in selected anthropometric and physiological traits were determined using ANOVA, t-test, and regression analysis. There were sex differences in the rate and pattern of age-related changes in certain characteristics such as relative weight, red blood cell count, monocyte count, thymol turbidity value, systolic blood pressure, and body temperature. Body weight, the body mass index (BMI, and total bilirubin level increased with advancing age, while body height decreased with age in both sexes. In conclusion, the aging process was associated with many regressive alterations in biological traits in both sexes but the rate and pattern of these changes depended on biological factors such as age and sex. There were only few characteristics which did not change significantly during the period under study. On the basis of comparison between the pattern of longitudinal changes with aging and the pattern of cross-sectional changes with age in the analyzed traits, we were able

  6. Longitudinal study of sexual function and vaginal changes after radiotherapy for cervical cancer

    DEFF Research Database (Denmark)

    Jensen, Pernille T; Groenvold, Mogens; Klee, Marianne C;

    2003-01-01

    PURPOSE: To investigate the longitudinal course of self-reported sexual function and vaginal changes in patients disease free after radiotherapy (RT) for locally advanced, recurrent, or persistent cervical cancer. MATERIALS AND METHODS: A total of 118 patients referred for RT were included....... The patients were assessed, using a validated self-assessment questionnaire, at the termination of RT and 1, 3, 6, 12, 18, and 24 months later. The results were compared with an age-matched control group from the general population. RESULTS: Persistent sexual dysfunction and adverse vaginal changes were...... reported throughout the 2 years after RT, with small changes over time: approximately 85% had low or no sexual interest, 35% had moderate to severe lack of lubrication, 55% had mild to severe dyspareunia, and 30% were dissatisfied with their sexual life. A reduced vaginal dimension was reported by 50...

  7. Assessing intratumor heterogeneity and tracking longitudinal and spatial clonal evolutionary history by next-generation sequencing.

    Science.gov (United States)

    Jiang, Yuchao; Qiu, Yu; Minn, Andy J; Zhang, Nancy R

    2016-09-13

    Cancer is a disease driven by evolutionary selection on somatic genetic and epigenetic alterations. Here, we propose Canopy, a method for inferring the evolutionary phylogeny of a tumor using both somatic copy number alterations and single-nucleotide alterations from one or more samples derived from a single patient. Canopy is applied to bulk sequencing datasets of both longitudinal and spatial experimental designs and to a transplantable metastasis model derived from human cancer cell line MDA-MB-231. Canopy successfully identifies cell populations and infers phylogenies that are in concordance with existing knowledge and ground truth. Through simulations, we explore the effects of key parameters on deconvolution accuracy and compare against existing methods. Canopy is an open-source R package available at https://cran.r-project.org/web/packages/Canopy/. PMID:27573852

  8. Longitudinal effects of group music instruction on literacy skills in low-income children.

    Science.gov (United States)

    Slater, Jessica; Strait, Dana L; Skoe, Erika; O'Connell, Samantha; Thompson, Elaine; Kraus, Nina

    2014-01-01

    Children from low-socioeconomic backgrounds tend to fall progressively further behind their higher-income peers over the course of their academic careers. Music training has been associated with enhanced language and learning skills, suggesting that music programs could play a role in helping low-income children to stay on track academically. Using a controlled, longitudinal design, the impact of group music instruction on English reading ability was assessed in 42 low-income Spanish-English bilingual children aged 6-9 years in Los Angeles. After one year, children who received music training retained their age-normed level of reading performance while a matched control group's performance deteriorated, consistent with expected declines in this population. While the extent of change is modest, outcomes nonetheless provide evidence that music programs may have value in helping to counteract the negative effects of low-socioeconomic status on child literacy development. PMID:25409300

  9. Longitudinal effects of group music instruction on literacy skills in low-income children.

    Directory of Open Access Journals (Sweden)

    Jessica Slater

    Full Text Available Children from low-socioeconomic backgrounds tend to fall progressively further behind their higher-income peers over the course of their academic careers. Music training has been associated with enhanced language and learning skills, suggesting that music programs could play a role in helping low-income children to stay on track academically. Using a controlled, longitudinal design, the impact of group music instruction on English reading ability was assessed in 42 low-income Spanish-English bilingual children aged 6-9 years in Los Angeles. After one year, children who received music training retained their age-normed level of reading performance while a matched control group's performance deteriorated, consistent with expected declines in this population. While the extent of change is modest, outcomes nonetheless provide evidence that music programs may have value in helping to counteract the negative effects of low-socioeconomic status on child literacy development.

  10. A longitudinal study of serum cobalamins and its binding proteins in lactating women

    DEFF Research Database (Denmark)

    Mørkbak, A L; Ramlau-Hansen, C H; Møller, U K;

    2006-01-01

    were analysed. RESULTS: No significant differences were observed in serum cobalamins or its binding proteins related to supplementation with vitamin B12 or the duration of lactation. Serum cobalamins remained unchanged from 3 weeks to 9 months post-partum. Total TC (holoTC) (median+/-s.e. pmol...... in HC during a 9-month period post-partum. No differences were observed between the vitamin B12-supplemented and the unsupplemented groups. Thus, supplementation with vitamin B12 has no impact on the circulating level of serum cobalamins or its binding proteins in a Danish population of lactating......OBJECTIVE: To examine longitudinal changes in serum cobalamins, transcobalamin (TC) and haptocorrin (HC) during lactation and to investigate the influence of vitamin B12 supplementation on these parameters. DESIGN: A 9-month follow-up study. SUBJECTS AND METHODS: Lactating mothers (N=89) including...

  11. A Longitudinal View of the Relationship Between Social Marginalization and Obesity

    Science.gov (United States)

    Apolloni, Andrea; Marathe, Achla; Pan, Zhengzheng

    We use 3 Waves of the Add Health data collected between 1994 and 2002 to conduct a longitudinal study of the relationship between social marginalization and the weight status of adolescents and young adults. Past studies have shown that overweight and obese children are socially marginalized. This research tests (1) if this is true when we account for the sample size of each group, (2) does this phenomenon hold over time and (3) is it obesity or social marginalization that precedes in time. Our results show that when the sample size for each group is considered, the share of friendship is conforming to the size of the group. This conformity seems to increase over time as the population becomes more obese. Finally, we find that obesity precedes social marginalization which lends credence to the notion that obesity causes social marginalization and not vice versa.

  12. Mapping longitudinal studies to risk factors in an ontology for dementia.

    Science.gov (United States)

    Roantree, Mark; O' Donoghue, Jim; O' Kelly, Noel; Pierce, Maria; Irving, Kate; Van Boxtel, Martin; Köhler, Sebastian

    2016-06-01

    A common activity carried out by healthcare professionals is to test various hypotheses on longitudinal study data in an effort to develop new and more reliable algorithms that might determine the possibility of developing certain illnesses. The INnovative, Midlife INtervention for Dementia Deterrence project provides input from a number of European dementia experts to identify the most accurate model of inter-related risk factors which can yield a personalized dementia-risk quotient and profile. This model is then validated against the large population-based prospective Maastricht Aging Study dataset. As part of this overall goal, the research presented in this article demonstrates how we can automate the process of mapping modifiable risk factors against large sections of the aging study and thus use information technology to provide more powerful query interfaces. PMID:25564493

  13. Political and social determinants of life expectancy in less developed countries: a longitudinal study

    Directory of Open Access Journals (Sweden)

    Lin Ro-Ting

    2012-01-01

    Full Text Available Abstract Background This study aimed to examine the longitudinal contributions of four political and socioeconomic factors to the increase in life expectancy in less developed countries (LDCs between 1970 and 2004. Methods We collected 35 years of annual data for 119 LDCs on life expectancy at birth and on four key socioeconomic indicators: economy, measured by log10 gross domestic product per capita at purchasing power parity; educational environment, measured by the literacy rate of the adult population aged 15 years and over; nutritional status, measured by the proportion of undernourished people in the population; and political regime, measured by the regime score from the Polity IV database. Using linear mixed models, we analyzed the longitudinal effects of these multiple factors on life expectancy at birth with a lag of 0-10 years, adjusting for both time and regional correlations. Results The LDCs' increases in life expectancy over time were associated with all four factors. Political regime had the least influence on increased life expectancy to begin with, but became significant starting in the 3rd year and continued to increase, while the impact of the other socioeconomic factors began strong but continually decreased over time. The combined effects of these four socioeconomic and political determinants contributed 54.74% - 98.16% of the life expectancy gains throughout the lag periods of 0-10 years. Conclusions Though the effect of democratic politics on increasing life expectancy was relatively small in the short term when compared to the effects of the other socioeconomic factors, the long-term impact of democracy should not be underestimated.

  14. A prospective, longitudinal study of growth, nutrition and sedentary behaviour in young children with cerebral palsy

    Directory of Open Access Journals (Sweden)

    Weir Kelly A

    2010-04-01

    Full Text Available Abstract Background Cerebral palsy is the most common cause of physical disability in childhood, occurring in one in 500 children. It is caused by a static brain lesion in the neonatal period leading to a range of activity limitations. Oral motor and swallowing dysfunction, poor nutritional status and poor growth are reported frequently in young children with cerebral palsy and may impact detrimentally on physical and cognitive development, health care utilisation, participation and quality of life in later childhood. The impact of modifiable factors (dietary intake and physical activity on growth, nutritional status, and body composition (taking into account motor severity in this population is poorly understood. This study aims to investigate the relationship between a range of factors - linear growth, body composition, oral motor and feeding dysfunction, dietary intake, and time spent sedentary (adjusting for motor severity - and health outcomes, health care utilisation, participation and quality of life in young children with cerebral palsy (from corrected age of 18 months to 5 years. Design/Methods This prospective, longitudinal, population-based study aims to recruit a total of 240 young children with cerebral palsy born in Queensland, Australia between 1st September 2006 and 31st December 2009 (80 from each birth year. Data collection will occur at three time points for each child: 17 - 25 months corrected age, 36 ± 1 months and 60 ± 1 months. Outcomes to be assessed include linear growth, body weight, body composition, dietary intake, oral motor function and feeding ability, time spent sedentary, participation, medical resource use and quality of life. Discussion This protocol describes a study that will provide the first longitudinal description of the relationship between functional attainment and modifiable lifestyle factors (dietary intake and habitual time spent sedentary and their impact on the growth, body composition and

  15. Bioecological Theory, Early Child Development and the Validation of the Population-Level Early Development Instrument

    Science.gov (United States)

    Guhn, Martin; Goelman, Hillel

    2011-01-01

    The Early Development Instrument (EDI; Janus and Offord in "Canadian Journal of Behavioural Science" 39:1-22, 2007) project is a Canadian population-level, longitudinal research project, in which teacher ratings of Kindergarten children's early development and wellbeing are linked to health and academic achievement variables at the individual…

  16. Drinking Distilled. Onset, course and treatment of alcohol use disorders in the general population

    NARCIS (Netherlands)

    M. Tuithof

    2015-01-01

    Although most people in Western society drink alcohol and regard this to be harmless and normal, some people drink excessively and develop an alcohol use disorder. This thesis examined the onset, course and treatment of alcohol use disorders in the general population using 3-year longitudinal data f

  17. Understanding the natural progression in %FEV1 decline in patients with cystic fibrosis:a longitudinal study

    OpenAIRE

    Taylor-Robinson, David; Whitehead, Margaret; Diderichsen, Finn; Olesen, Hanne Vebert; Pressler, Tania; Rosalind L Smyth; Diggle, Peter

    2012-01-01

    Background Forced expiratory volume in 1 s as a percentage of predicted (%FEV1) is a key outcome in cystic fibrosis (CF) and other lung diseases. As people with CF survive for longer periods, new methods are required to understand the way %FEV1 changes over time. An up to date approach for longitudinal modelling of %FEV1 is presented and applied to a unique CF dataset to demonstrate its utility at the clinical and population level. Methods and findings The Danish CF register contains 70 448 %...

  18. Minor Delinquency and Immigration: A Longitudinal Study among Male Adolescents

    Science.gov (United States)

    Titzmann, Peter F.; Silbereisen, Rainer K.; Mesch, Gustavo

    2014-01-01

    On the basis of general theories of delinquency and the specific situation of immigrants, this longitudinal study investigated predictors of initial levels and rates of change in delinquency among 188 male ethnic German Diaspora immigrants from the former Soviet Union (FSU) in Germany, 237 male native German adolescents, and 182 male Jewish…

  19. Exploring Intensive Longitudinal Measures of Student Engagement in Blended Learning

    Science.gov (United States)

    Henrie, Curtis R.; Bodily, Robert; Manwaring, Kristine C.; Graham, Charles R.

    2015-01-01

    In this exploratory study we used an intensive longitudinal approach to measure student engagement in a blended educational technology course, collecting both self-report and observational data. The self-report measure included a simple survey of Likert-scale and open-ended questions given repeatedly during the semester. Observational data were…

  20. Predictors of Adolescent Breakfast Consumption: Longitudinal Findings from Project EAT

    Science.gov (United States)

    Bruening, Meg; Larson, Nicole; Story, Mary; Neumark-Sztainer, Dianne; Hannan, Peter

    2011-01-01

    Objective: To identify predictors of breakfast consumption among adolescents. Methods: Five-year longitudinal study Project EAT (Eating Among Teens). Baseline surveys were completed in Minneapolis-St. Paul schools and by mail at follow-up by youth (n = 800) transitioning from middle to high school. Linear regression models examined associations…

  1. Longitudinal Predictors of Aerobic Performance in Adolescent Soccer Players

    NARCIS (Netherlands)

    Valente-dos-Santos, Joao; Coelho-e-Silva, Manuel J.; Duarte, Joao; Figueiredo, Antonio J.; Liparotti, Joao R.; Sherar, Lauren B.; Elferink-Gemser, Marije T.; Malina, Robert M.

    2012-01-01

    Background. The importance of aerobic performance in youth soccer is well established. The aim of the present study was to evaluate the contributions of chronological age (CA), skeletal age (SA), body size, and training to the longitudinal development of aerobic performance in youth male soccer play

  2. A Longitudinal Investigation of Commitment Dynamics in Cohabiting Relationships

    Science.gov (United States)

    Rhoades, Galena K.; Stanley, Scott M.; Markman, Howard J.

    2012-01-01

    This longitudinal study followed 120 cohabiting, opposite-sex couples over 8 months to test hypotheses derived from commitment theory about how two types of commitment (dedication and constraint) operate during cohabitation. In nearly half the couples, there were large differences between partners in terms of dedication. These differences were…

  3. Longitudinal Effects of Domestic Violence on Employment and Welfare Outcomes

    Science.gov (United States)

    Lindhorst, Taryn; Oxford, Monica; Gillmore, Mary Rogers

    2007-01-01

    This study uses longitudinal data spanning 13 years from a study of 234 adolescent mothers to evaluate the effects of cumulative domestic violence on employment and welfare use before and after welfare reform. Domestic violence increased the odds of unemployment after welfare reform, but not before; domestic violence had no effect on welfare use…

  4. Genetics and Genomics of Longitudinal Lung Function Patterns in Asthmatics

    NARCIS (Netherlands)

    McGeachie, Michael J; Yates, Katherine P; Zhou, Xiaobo; Guo, Feng; Sternberg, Alice L; Van Natta, Mark L; Wise, Robert A; Szefler, Stanley J; Sharma, Sunita; Kho, Alvin T; Cho, Michael H; Croteau-Chonka, Damien C; Castaldi, Peter J; Jain, Gaurav; Sanyal, Amartya; Zhan, Ye; Lajoie, Bryan R; Dekker, Job; Stamatoyannopoulos, John; Covar, Ronina A; Zeiger, Robert S; Adkinson, N Franklin; Williams, Paul V; Kelly, H William; Grasemann, Hartmut; Vonk, Judith M; Koppelman, Gerard H; Postma, Dirkje S; Raby, Benjamin A; Houston, Isaac; Lu, Quan; Fuhlbrigge, Anne L; Tantisira, Kelan G; Silverman, Edwin K; Tonascia, James; Strunk, Robert C; Weiss, Scott T

    2016-01-01

    RATIONALE: Patterns of longitudinal lung function growth and decline in childhood asthma have been shown to be important in determining risk for future respiratory ailments including chronic airway obstruction and chronic obstructive pulmonary disease (COPD). OBJECTIVES: To determine the genetic und

  5. Unemployment and psychological distress among graduates: A longitudinal study

    NARCIS (Netherlands)

    Schaufeli, Wilmar B.; Van Yperen, Nico W.

    1992-01-01

    A longitudinal study which addresses the relationship between unemployment and psychological distress in Dutch technical college graduates is presented. Two samples were studied: sample 1 (N = 635) consisted of students leaving technical college and sample 2 (N = 487) consisted of technical college

  6. Longitudinal Effects of Parental Bereavement on Adolescent Developmental Competence

    Science.gov (United States)

    Brent, David A.; Melhem, Nadine M.; Masten, Ann S.; Porta, Giovanna; Walker Payne, Monica

    2012-01-01

    The aim of this study is to assess the impact of sudden parental bereavement on subsequent attainment of developmental competencies. This longitudinal study reports on 126 youth bereaved by sudden parental death (suicide, accident, or natural death) and 116 demographically similar nonbereaved controls assessed at 9, 21, 33, and 62 months after…

  7. Homeschooling Education: Longitudinal Study of Methods, Materials, and Curricula

    Science.gov (United States)

    Hanna, Linda G.

    2012-01-01

    In a comprehensive study of two-hundred fifty homeschooling families in urban, rural and suburban areas of the Commonwealth of Pennsylvania, the researcher examined all aspects of the instruction, materials and curricula employed by the families in a ten-year longitudinal study from 1998 through 2008. The researcher conducted interviews and…

  8. A Longitudinal Study on Internship Effectiveness in Vocational Higher Education

    Science.gov (United States)

    Wan, Chin-Sheng; Yang, Jen-te; Cheng, Shu-yun; Su, Chiakai

    2013-01-01

    A cooperative education experience (or internship placement) is an essential component of the curricula of vocational higher education. The efficacy of internship placements has become one of the major concerns facing those who develop education curricula. The purpose of this longitudinal study was to explore the relationships among the…

  9. Application of optical longitudinal tomography for dental introscopy

    Science.gov (United States)

    Levin, Gennady G.; Burgansky, Alexander A.; Levandovski, Alexei G.

    1997-08-01

    A new method of dental introscopy in-vitro is suggested by the authors. This method implies the usage of longitudinal tomography techniques and is characterized by non-invasive and non-harmful diagnostics features, as well as interactive regime of image reconstruction which lets an operator (doctor) to control the diagnostics process in real time. He-Ne laser emission is used for obtaining of the projections. By the means of longitudinal tomography, images of different sections of an object (tooth) can be reconstructed. An experiment was held by the authors in which 100 projections of a tooth (premolar) were obtained and images of 10 different sections were reconstructed. These images were later compared to real sections of the tooth. This experiment proved that optical longitudinal tomography can be successfully used for dental introscopy. Authors claim that optical tomographic methods can be used for diagnostics of other biological objects as well. Such objects are characterized by spatial geometrical anisotropy (tubular bones, phalanxes of fingers, penis, etc.). It is especially promising to use this method for children's dentistry. the authors discuss some features of the data acquisition system for optical longitudinal tomography. Reconstruction algorithms are described. The results of experimental reconstruction are presented and advantages of this diagnostics method are discussed.

  10. A Rough Guide to New Zealand's Longitudinal Business Database

    OpenAIRE

    Richard Fabling

    2009-01-01

    Statistics New Zealand fs prototype Longitudinal Business Database is a rich resource for understanding the behaviour of New Zealand firms. In this paper we describe the elements of the database, access protocols for researchers, and potential future developments in the linking and availability of business data in New Zealand.

  11. Reciprocal Longitudinal Relations between Nonresident Father Involvement and Adolescent Delinquency

    Science.gov (United States)

    Coley, Rebekah Levine; Medeiros, Bethany L.

    2007-01-01

    Using a representative sample of low-income, primarily minority adolescents (N=647, aged 10-14 years at Wave 1), this study examined bidirectional longitudinal relations between nonresident father involvement, defined as contact and responsibility for children's care and behavior, and adolescent engagement in delinquent activities. Autoregressive…

  12. Acquisition patterns of financial products : A longitudinal investigation

    NARCIS (Netherlands)

    Paas, Leonard J.; Bijmolt, Tammo H. A.; Vermunt, Jeroen K.

    2007-01-01

    Acquisition pattern analysis investigates orders in which households acquire products. Extant empirical studies employ cross-sectional data, providing limited insight into acquisition orders and no insight into timing of product acquisitions. We use an extensive longitudinal database for studying ac

  13. Predicting a Longitudinal Guttman Simplex of Adolescent Substance Use.

    Science.gov (United States)

    McGuigan, Kimberly A.; And Others

    The longitudinal Guttman simplex (LGS), a method of modeling stage sequences or levels over time, allows for individual differences in sequence progression or development. The LGS is particularly appropriate in modeling tobacco, alcohol, and marijuana use stages with adolescent subjects where relationships among drugs and degree of involvement may…

  14. Prediction of the development of reading comprehension: a longitudinal study

    NARCIS (Netherlands)

    Verhoeven, L.T.W.; Leeuwe, J.F.J. van

    2008-01-01

    Specific effects of word decoding, vocabulary and listening comprehension abilities on the development of reading comprehension were longitudinally examined for a representative sample of 2143 Dutch children throughout the elementary school period. An attempt was made to test two theoretical framewo

  15. Nonlinear Latent Curve Models for Multivariate Longitudinal Data

    Science.gov (United States)

    Blozis, Shelley A.; Conger, Katherine J.; Harring, Jeffrey R.

    2007-01-01

    Latent curve models have become a useful approach to analyzing longitudinal data, due in part to their allowance of and emphasis on individual differences in features that describe change. Common applications of latent curve models in developmental studies rely on polynomial functions, such as linear or quadratic functions. Although useful for…

  16. Sex Differences in the Longitudinal Prediction of Adult Personality.

    Science.gov (United States)

    Sutton-Smith, B.; Rosenberg, B. G.

    This paper deals with two sets of data-one that fails to find any long-term sex differences in adults, and another which seems to find such differences. The Berkeley Guidance Study offers longitudinal data in which no variables differentiate between the two sexes at all age levels. From these results, the authors conclude that the normal course of…

  17. Bayesian joint modeling of longitudinal and spatial survival AIDS data.

    Science.gov (United States)

    Martins, Rui; Silva, Giovani L; Andreozzi, Valeska

    2016-08-30

    Joint analysis of longitudinal and survival data has received increasing attention in the recent years, especially for analyzing cancer and AIDS data. As both repeated measurements (longitudinal) and time-to-event (survival) outcomes are observed in an individual, a joint modeling is more appropriate because it takes into account the dependence between the two types of responses, which are often analyzed separately. We propose a Bayesian hierarchical model for jointly modeling longitudinal and survival data considering functional time and spatial frailty effects, respectively. That is, the proposed model deals with non-linear longitudinal effects and spatial survival effects accounting for the unobserved heterogeneity among individuals living in the same region. This joint approach is applied to a cohort study of patients with HIV/AIDS in Brazil during the years 2002-2006. Our Bayesian joint model presents considerable improvements in the estimation of survival times of the Brazilian HIV/AIDS patients when compared with those obtained through a separate survival model and shows that the spatial risk of death is the same across the different Brazilian states. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26990773

  18. Status of Longitudinal Polarized Parton Densities and Higher Twist

    OpenAIRE

    Leader, Elliot; Sidorov, Alexander V.; Stamenov, Dimiter B.

    2009-01-01

    The present status of the longitudinal polarized parton densities (PDFs) and the contribution of their first moments to the nucleon spin is discussed. Special attention is paid to the role of higher twist effects in determining the PDFs and to the polarized strange quark and gluon densities, which are still not well determined from the present data.

  19. Effects of First Occasion Test Experience on Longitudinal Cognitive Change

    Science.gov (United States)

    Salthouse, Timothy A.

    2013-01-01

    Effects of additional test experience on longitudinal change in 5 cognitive abilities was examined in a sample of healthy adults ranging from 18 to 80 years of age. Participants receiving experience with parallel versions of the cognitive tests on the first occasion had more positive cognitive change an average of 2.5 years later than participants…

  20. Intimate Partner Violence and Welfare Participation: A Longitudinal Causal Analysis

    Science.gov (United States)

    Cheng, Tyrone C.

    2013-01-01

    This longitudinal study examined the temporal-ordered causal relationship between intimate partner violence (IPV), five mental disorders (depression, generalized anxiety disorder, social phobia, panic attack, posttraumatic stress disorder [PTSD]), alcohol abuse/dependence, drug abuse/ dependence, treatment seeking (from physician, counselor, and…

  1. Concurrent and Longitudinal Predictors of Calculation Skills in Preschoolers

    Science.gov (United States)

    Tobia, Valentina; Bonifacci, Paola; Marzocchi, Gian Marco

    2016-01-01

    Early calculation abilities in preschoolers are predictive of mathematics achievement in subsequent grades (e.g., Jordan et al. 2009). Two studies were conducted to evaluate concurrent and longitudinal predictors of early calculation skills. In the first study, 102 preschoolers (57.8% female; mean age?=?60.57?±?8.66 months) were given vocabulary,…

  2. Exploring Dynamism in Willingness to Communicate: A Longitudinal Case Study

    Science.gov (United States)

    Cao, Yiqian Katherine

    2013-01-01

    This paper examines dynamism in students' situational willingness to communicate (WTC) within a second language classroom. This longitudinal study involved twelve English as a Second Language (ESL) participants who enrolled in an English for Academic Purposes (EAP) programme in New Zealand for five months. Based on data from classroom…

  3. Giftedness, Trauma, and Development: A Qualitative, Longitudinal Case Study

    Science.gov (United States)

    Peterson, Jean Sunde

    2014-01-01

    A qualitative, longitudinal, phenomenological case study explored how a gifted female experienced various life events and aspects of development during adolescence and young adulthood (ages 15-30 years), particularly as related to multiple traumatic experiences, which were revealed late in the first year of the study. Additional experiences, well…

  4. Developmental Precursors of Romantic Relationships: A Longitudinal Analysis.

    Science.gov (United States)

    Collins, W. Andrew; Hennighausen, Katherine C.; Schmit, David Taylor; Sroufe, L. Alan

    1997-01-01

    Presents evidence that differences among adolescents' behavior in romantic relationships are imbedded in both earlier and concurrent relationship experiences that foster a capacity for intimacy. Summarizes a 20-year longitudinal study based on this view, with particular attention to links between relationships with parents and interactions with…

  5. Modeling Longitudinal Dynamics in the Fermilab Booster Synchrotron

    Energy Technology Data Exchange (ETDEWEB)

    Ostiguy, Jean-Francois [Fermilab; Bhat, Chandra [Fermilab; Lebedev, Valeri [Fermilab

    2016-06-01

    The PIP-II project will replace the existing 400 MeV linac with a new, CW-capable, 800 MeV superconducting one. With respect to current operations, a 50% increase in beam intensity in the rapid cycling Booster synchrotron is expected. Booster batches are combined in the Recycler ring; this process limits the allowed longitudinal emittance of the extracted Booster beam. To suppress eddy currents, the Booster has no beam pipe; magnets are evacuated, exposing the beam to core laminations and this has a substantial impact on the longitudinal impedance. Noticeable longitudinal emittance growth is already observed at transition crossing. Operation at higher intensity will likely necessitate mitigation measures. We describe systematic efforts to construct a predictive model for current operating conditions. A longitudinal only code including a laminated wall impedance model, space charge effects, and feedback loops is developed. Parameter validation is performed using detailed measurements of relevant beam, rf and control parameters. An attempt is made to benchmark the code at operationally favorable machine settings.

  6. Forward scattering amplitude of the virtual longitudinal photon in QED

    OpenAIRE

    Samsonov, A. V.

    1997-01-01

    Forward scattering amplitude of the virtual longitudinal photon at zero energy on electron in QED in the limit of small photon virtualities is calculated. The first radiation corrections are taken into account. Two terms in the expansion over photon virtualities are obtained.

  7. Longitudinal cross section and asymmetries for jets in leptoproduction

    International Nuclear Information System (INIS)

    We have calculated the longitudinal and other polarization dependent cross sections for jet production in deep inelastic electron-proton scattering up to order αs of the quark-gluon coupling constant and compared them with estimates of the non-perturbative contributions. (orig.)

  8. Anxiety Sensitivity and Panic Attacks: A 1-Year Longitudinal Study

    Science.gov (United States)

    Li, Wen; Zinbarg, Richard E.

    2007-01-01

    The hypothesis that anxiety sensitivity (AS) is a risk factor for panic genesis has obtained compelling support, but the clinical/practical importance of AS in panic genesis has been questioned. In addition, the association between panic experience and AS increase has not been clearly demonstrated. Through this 1-year longitudinal study among…

  9. A Bayesian semiparametric model for bivariate sparse longitudinal data.

    Science.gov (United States)

    Das, Kiranmoy; Li, Runze; Sengupta, Subhajit; Wu, Rongling

    2013-09-30

    Mixed-effects models have recently become popular for analyzing sparse longitudinal data that arise naturally in biological, agricultural and biomedical studies. Traditional approaches assume independent residuals over time and explain the longitudinal dependence by random effects. However, when bivariate or multivariate traits are measured longitudinally, this fundamental assumption is likely to be violated because of intertrait dependence over time. We provide a more general framework where the dependence of the observations from the same subject over time is not assumed to be explained completely by the random effects of the model. We propose a novel, mixed model-based approach and estimate the error-covariance structure nonparametrically under a generalized linear model framework. We use penalized splines to model the general effect of time, and we consider a Dirichlet process mixture of normal prior for the random-effects distribution. We analyze blood pressure data from the Framingham Heart Study where body mass index, gender and time are treated as covariates. We compare our method with traditional methods including parametric modeling of the random effects and independent residual errors over time. We conduct extensive simulation studies to investigate the practical usefulness of the proposed method. The current approach is very helpful in analyzing bivariate irregular longitudinal traits. PMID:23553747

  10. Bullying and Empathy: A Short-Term Longitudinal Investigation

    Science.gov (United States)

    Stavrinides, Panayiotis; Georgiou, Stelios; Theofanous, Vaso

    2010-01-01

    The aim of this study was to test the direction of effect in the relationship between bullying and empathy. The participants were 205 sixth-grade students, randomly selected from urban and rural schools in Cyprus. A six-month, two-time-point longitudinal design was used in which the participants completed the bullying subscale of the Revised…

  11. A Longitudinal Investigation of Peer Sexual Harassment Victimization in Adolescence

    Science.gov (United States)

    Petersen, Jennifer L.; Hyde, Janet Shibley

    2009-01-01

    The current study describes longitudinal trends in sexual harassment by adolescent peers and highlights gender, pubertal status, attractiveness, and power as predictors of harassment victimization. At the end of 5th, 7th, and 9th grades, 242 adolescents completed questionnaires about sexual harassment victimization, pubertal status, and perceived…

  12. A Fresh Look at Longitudinal Standing Waves on a Spring

    Science.gov (United States)

    Rutherford, Casey

    2013-01-01

    Transverse standing waves produced on a string, as shown in Fig. 1, are a common demonstration of standing wave patterns that have nodes at both ends. Longitudinal standing waves can be produced on a helical spring that is mounted vertically and attached to a speaker, as shown in Fig. 2, and used to produce both node-node (NN) and node-antinode…

  13. Longitudinal Evaluation of the Psychomotor Syndrome in Schizophrenia

    NARCIS (Netherlands)

    Docx, L.; Sabbe, B.G.C.; Fransen, E.; Bervoets, C.; Hulstijn, W.; Bossche, M.J.A. Van Den; Vermeylen, S.; Temmerman, A.; Morsel, A.M.; Morrens, M.

    2014-01-01

    Little is known about the longitudinal course of psychomotor signs and symptoms after illness onset in schizophrenia. Therefore, a 1-year follow-up study was conducted in which patients with schizophrenia were assessed three times with an extensive battery of psychomotor rating scales and tests. The

  14. Left ventricular global longitudinal strain in acute myocardial infarction

    DEFF Research Database (Denmark)

    Ersbøll, Mads

    Systolic dysfunction, clinical heart failure and elevated levels of neurohormonal peptides are major predictors of adverse outcome after acute myocardial infarction (MI). In the present thesis we evaluated global longitudinal strain (GLS) in patients with acute MI in relation to neurohormonal...

  15. A Chinese Longitudinal Study on Work/Family Enrichment

    Science.gov (United States)

    Lu, Luo

    2011-01-01

    Purpose: The purpose of this paper is to explore reciprocal relationships between work/family resources, work/family enrichment (WFE), and work/family satisfaction in a Chinese society. Design/methodology/approach: A longitudinal design was adopted using a three-wave panel sample. Data were obtained from 310 Taiwanese employees on three occasions,…

  16. Longitudinal stress fracture of the femur: A rare presentation

    Science.gov (United States)

    Bilreiro, Carlos; Bahia, Carla; Castro, Miguel Oliveira e

    2016-01-01

    We present the case of an 80 year old woman with hip pain, caused by a longitudinal femoral insufficiency stress fracture, depicted with radiographs, CT and MR. This type of fracture is very rare, with only a few cases reported. We conducted a literature review and compared the findings with the present case. PMID:27069976

  17. Longitudinal Analysis of Academic Burnout in Korean Middle School Students.

    Science.gov (United States)

    Kim, Boyoung; Lee, Minyoung; Kim, Keunhwa; Choi, Hyunju; Lee, Sang Min

    2015-10-01

    The purpose of the study was to investigate the longitudinal relationships between the initial values and slopes of three dimensions of burnout syndrome (i.e. emotional exhaustion, cynicism and academic inefficacy). The study utilized four-wave longitudinal data from a total of 367 (81.6% response rate) middle school students in South Korea. Comprising a 6-month interval survey, the first survey was conducted in June 2010, the second in December 2010, the third in June 2011 and the fourth in December 2011. All participants were 13-year-olds at the first and second surveys, and 14-year-olds at the third and fourth surveys. The Maslach Burnout Inventory-Student Survey was used for each survey to assess the level of academic burnout. The longitudinal data were analysed using latent growth modelling. The results of the study indicated that high initial values (intercept) for emotional exhaustion were associated with a higher rate of increase (slope) in cynicism and academic inefficacy. On the other hand, high initial values for cynicism and academic inefficacy were associated with a lower rate of increase in the other dimensions. This longitudinal study should promote understanding of burned-out students and contribute to the literature by informing the design of prevention programmes for academic burnout. PMID:24452964

  18. Investing in Better Outcomes: The Delaware Early Childhood Longitudinal Study.

    Science.gov (United States)

    Gamel-McCormick, Michael; Amsden, Deborah

    This report details the outcomes for children enrolled in two types of early intervention programs in Delaware: those serving young children with disabilities and those serving young children living in poverty. The Delaware Early Childhood Longitudinal Study was designed as a retrospective, two-group, posttest-only design. Participating in the…

  19. Longitudinal Construct Validity of Brief Symptom Inventory Subscales in Schizophrenia

    Science.gov (United States)

    Long, Jeffrey D.; Harring, Jeffrey R.; Brekke, John S.; Test, Mary Ann; Greenberg, Jan

    2007-01-01

    Longitudinal validity of Brief Symptom Inventory subscales was examined in a sample (N = 318) with schizophrenia-related illness measured at baseline and every 6 months for 3 years. Nonlinear factor analysis of items was used to test graded response models (GRMs) for subscales in isolation. The models varied in their within-time and between-times…

  20. A Longitudinal Study of Children's Social Adjustment during Elementary School.

    Science.gov (United States)

    Battistich, Victor; Solomon, Daniel

    A 7-year, longitudinal study of children's social development from kindergarten through sixth grade was designed to identify unusually prosocial children and characteristics that differentiated them from average and antisocial peers. Another objective was to identify functional socioemotional predictors of changes in children's social adjustment.…