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Sample records for black-white population longitudinal

  1. Epidemiology of hypertension from childhood to young adulthood in black, white, and Hispanic population samples.

    OpenAIRE

    Berenson, G. S.; Wattigney, W A; Webber, L S

    1996-01-01

    RESEARCHERS RECORDED BLOOD PRESSURE LEVELS of children and adolescents in the Bogalusa Heart Study (black and white populations) and in the Brooks Country Study (Hispanic population). Hispanic children had smaller stature, while whites and Hispanics tended to be fatter than blacks in childhood. In Bogalusa, black boys showed higher blood pressure levels. Hispanic girls showed lower systolic blood pressure than the other ethnic groups. In cultures with a high prevalence of hypertension, such a...

  2. Intergenerational Family Predictors of the Black-White Achievement Gap

    Science.gov (United States)

    Mandara, Jelani; Varner, Fatima; Greene, Nereira; Richman, Scott

    2009-01-01

    The authors examined intergenerational family predictors of the Black-White achievement gap among 4,406 adolescents from the National Longitudinal Survey of Youth. An intergenerational model of the process by which family factors contribute to the achievement gap was also tested. The results showed that the ethnic gaps in socioeconomic status…

  3. A Developmental Shift in Black-White Differences in Depressive Affect across Adolescence and Early Adulthood: The Influence of Early Adult Social Roles and Socio-Economic Status

    Science.gov (United States)

    Jager, Justin

    2011-01-01

    This study examined Black-White differences in growth of depressive affect using a longitudinal sample of middle-class, suburban U.S. subjects (n = 956) that spanned from adolescence to early adulthood. Specifically, this study examined whether Black-White differences in growth of depressive affect shift over time, and the extent to which that…

  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. 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

  6. 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...

  7. 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...

  8. 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

  9. 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

  10. 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...

  11. 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...

  12. School Composition and the Black-White Achievement Gap. NCES 2015-018

    Science.gov (United States)

    Bohrnstedt, G.; Kitmitto, S.; Ogut, B.; Sherman, D.; Chan, D.

    2015-01-01

    School Composition and the Black-White Achievement Gap explores public schools' demographic composition, in particular, the proportion of Black students enrolled in schools (also referred to "Black student density" in schools) and its relation to the Black-White achievement gap. This NCES study, the first of its kind, used the 2011 NAEP…

  13. 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…

  14. 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

  15. 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.

  16. 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 ...

  17. School Composition and the Black-White Achievement Gap: Methodology Companion. NCES 2015-032

    Science.gov (United States)

    Bohrnstedt, G.; Kitmitto, S.; Ogut, B.; Sherman, D.; Chan, D.

    2015-01-01

    The School Composition and the Black-White Achievement Gap study was undertaken by the National Center for Education Statistics to present both descriptive and associative information on the relationships among the percentage of students in a school who were Black (referred to as "Black student density" or "density"), the…

  18. 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)

  19. Are Black-White Differences in Females' Body Dissatisfaction Decreasing? A Meta-Analytic Review

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    Roberts, Alan; Cash, Thomas F.; Feingold, Alan; Johnson, Blair T.

    2006-01-01

    Proponents of the sociocultural model of eating disorders have suggested that ethnic differences in body dissatisfaction may be diminishing as the thin ideal of beauty becomes more widely disseminated among minority women. In a meta-analysis, the authors examined temporal trends in Black-White differences and also examined whether these…

  20. 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…

  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. Pregnancy Risk among Black, White, and Hispanic Teen Girls in New York City Public Schools

    OpenAIRE

    Waddell, Elizabeth Needham; Orr, Mark G.; Sackoff, Judith; Santelli, John S.

    2010-01-01

    Disparities in teen pregnancy rates are explained by different rates of sexual activity and contraceptive use. Identifying other components of risk such as race/ethnicity and neighborhood can inform strategies for teen pregnancy prevention. Data from the 2005 and 2007 New York City Youth Risk Behavior Surveys were used to model demographic differences in odds of recent sexual activity and birth control use among black, white, and Hispanic public high school girls. Overall pregnancy risk was c...

  3. Vitamin D may be a link to black-white disparities in adverse birth outcomesab

    OpenAIRE

    Bodnar, Lisa M.; Simhan, Hyagriv N.

    2010-01-01

    In the United States, significant, intractable disparities exist in rates of major pregnancy outcomes between non-Hispanic black and non-Hispanic white women. A previously unexplored candidate influence on the black-white disparity in adverse birth outcomes is maternal vitamin D status. This review summarizes the evidence relating maternal vitamin D to preeclampsia, spontaneous preterm birth, gestational diabetes, and fetal growth restriction, and addresses gaps in our understanding of the co...

  4. Like a virgin (mother): analysis of data from a longitudinal, US population representative sample survey

    OpenAIRE

    Herring, Amy H.; Attard, Samantha M.; Gordon-Larsen, Penny; Joyner, William H; Halpern, Carolyn T.

    2013-01-01

    Objective To estimate the incidence of self report of pregnancy without sexual intercourse (virgin pregnancy) and factors related to such reporting, in a population representative group of US adolescents and young adults. Design Longitudinal, population representative sample survey. Setting Nationally representative, multiethnic National Longitudinal Study of Adolescent Health, United States. Participants 7870 women enrolled at wave I (1995) and completing the most recent wave of data collect...

  5. 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)

  6. 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…

  7. 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...

  8. Longitudinal population-based studies of affective disorders: Where to from here?

    OpenAIRE

    Beard John R; Galea Sandro; Vlahov David

    2008-01-01

    Abstract Background Longitudinal, population-based, research is important if we are to better characterize the lifetime patterns and determinants of affective disorders. While studies of this type are becoming increasingly prevalent, there has been little discussion about the limitations of the methods commonly used. Methods Discussion paper including a brief review of key prospective population-based studies as the basis for a critical appraisal of current approaches. Results We identified a...

  9. 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

  10. Class and Schools: Using Social, Economic, and Educational Reform to Close The Black?White Achievement Gap

    Science.gov (United States)

    Taylor, Dianne L.

    2005-01-01

    This paper presents a comprehensive review of Richard Rothstein's book "Class and Schools: Using Social, Economic, and Educational Reform to Close the Black-White Achievement Gap" (Washington, DC: Economic Policy Institute, 2004). The insights offered in this book are timely in light of the No Child Left Behind legislation that puts the force of…

  11. 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…

  12. 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…

  13. 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 ...

  14. Social determinants of Black-White disparities in breast cancer mortality: a review.

    Science.gov (United States)

    Gerend, Mary A; Pai, Manacy

    2008-11-01

    Despite the recent decline in breast cancer mortality, African American women continue to die from breast cancer at higher rates than do White women. Beyond the fact that breast cancer tends to be a more biologically aggressive disease in African American than in White women, this disparity in breast cancer mortality also reflects social barriers that disproportionately affect African American women. These barriers hinder cancer prevention and control efforts and modify the biological expression of disease. The present review focuses on delineating social, economic, and cultural factors that are potentially responsible for Black-White disparities in breast cancer mortality. This review was guided by the social determinants of health disparities model, a model that identifies barriers associated with poverty, culture, and social injustice as major causes of health disparities. These barriers, in concert with genetic, biological, and environmental factors, can promote differential outcomes for African American and White women along the entire breast cancer continuum, from screening and early detection to treatment and survival. Barriers related to poverty include lack of a primary care physician, inadequate health insurance, and poor access to health care. Barriers related to culture include perceived invulnerability, folk beliefs, and a general mistrust of the health care system. Barriers related to social injustice include racial profiling and discrimination. Many of these barriers are potentially modifiable. Thus, in addition to biomedical advancements, future efforts to reduce disparities in breast cancer mortality should address social barriers that perpetuate disparities among African American and White women in the United States. PMID:18990731

  15. Water column depth and light intensity modulate the zebrafish preference response in the black/white test.

    Science.gov (United States)

    Córdova, Sandro Daniel; Dos Santos, Thainá Garbino; de Oliveira, Diogo Losch

    2016-04-21

    Currently, the black/white preference test has been used to evaluate anxiety-like behaviors in zebrafish. However, several inconsistent results have been reported across literature. Since animal behavior can be influenced by several environmental factors, the main goal of the present study was to investigate the influence of different water column depths and light intensities on zebrafish behavioral responses in the black/white test. On a 4cm water column depth, animals spent more time in the black than in the white compartment. However, when animals were tested in an 8cm water column, no significant difference was found. Using an inclined acrylic floor inside the aquarium, animals spent more time in the deep compartment when this was black. However, there is no difference in time spent in each compartment when the deeper compartment was white. For light intensity test, animals showed preference for the white compartment only when both compartments were illuminated with 100lx. For the others illumination settings, there was no difference in the compartment preference. In conclusion, our results suggest that variations in water column depth and light intensity can modulate zebrafish preference in the black/white test. These variations may be implicated in the discrepancies observed in literature. PMID:26960010

  16. 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

  17. A fast chopper for programmed population of the longitudinal phase space of the AGS booster

    International Nuclear Information System (INIS)

    This paper reports on a fast chopper which has been built, that can switch the beam injected into the AGS or AGS Booster on and off with rise and fall times in the order of 10 ns. The chopper will be used to control the initial population of longitudinal phase space in order to eliminate rf capture losses and achieve an optimal phase space density distribution. The chopper operates on the 35 keV H- beam between the ion source and the RFQ. The interaction between the electrostatic fields of the chipper and the space charge neutralizing ions in the beam has been seen to be a significant but manageable effect

  18. 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.

  19. 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

  20. 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

  1. Longitudinal population-based studies of affective disorders: Where to from here?

    Directory of Open Access Journals (Sweden)

    Beard John R

    2008-09-01

    Full Text Available Abstract Background Longitudinal, population-based, research is important if we are to better characterize the lifetime patterns and determinants of affective disorders. While studies of this type are becoming increasingly prevalent, there has been little discussion about the limitations of the methods commonly used. Methods Discussion paper including a brief review of key prospective population-based studies as the basis for a critical appraisal of current approaches. Results We identified a number of common methodological weaknesses that restrict the potential of longitudinal research to characterize the diversity, prognosis, and determinants of affective disorders over time. Most studies using comprehensive diagnostic instruments have either been of relatively brief duration, or have suffered from long periods between waves. Most etiologic research has focused on first onset diagnoses, although these may be relatively uncommon after early adulthood and the burden of mental disorders falls more heavily on individuals with recurring disorders. Analysis has tended to be based on changes in diagnostic status rather than anges in symptom levels, limiting study power. Diagnoses have generally been treated as homogeneous entities and few studies have explored whether diagnostic subtypes such as atypical depression vary in their etiology or prognosis. Little research has considered whether there are distinct trajectories of symptoms over time and most has focused on individual disorders such as depression, rather than considering the relationship over time between symptoms of different affective disorders. There has also been limited longitudinal research on factors in the physical or social environment that may influence the onset, recurrence or chronicity of symptoms. Conclusion Many important, and in some respects quite basic, questions remain about the trajectory of depression and anxiety disorders over the life course and the factors that

  2. 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...

  3. 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

  4. 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

  5. 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…

  6. 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.

  7. 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

  8. The association between intelligence and telomere length: a longitudinal population based study.

    Directory of Open Access Journals (Sweden)

    Eva M Kingma

    Full Text Available 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 behaviors and low socioeconomic position. The study was performed in a longitudinal population-based cohort study of 895 participants (46.8% males. Intelligence was measured with the Generalized Aptitude-Test Battery at mean age 52.8 years (33-79 years, SD=11.3. Leukocyte telomere length was measured by PCR. Lifestyle and socioeconomic factors were assessed using written self-report measures. Linear regression analyses, adjusted for age, sex, and telomere length measured at the first assessment wave (T1, showed that low intelligence was associated with shorter leukocyte telomere length at approximately 2 years follow-up (beta= .081, t=2.160, p= .031. Nearly 40% of this association was explained by an unhealthy lifestyle, while low socioeconomic position did not add any significant mediation. Low intelligence may be a risk factor for accelerated biological ageing, thereby providing an explanation for its association with poor health and mortality.

  9. 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

  10. 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…

  11. 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

  12. 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...

  13. 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

  14. 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

  15. 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.

  16. 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

  17. 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 ...

  18. Black-white differences in cancer risk in Harare, Zimbabwe, during 1991-2010.

    Science.gov (United States)

    Chokunonga, Eric; Windridge, Peter; Sasieni, Peter; Borok, Margaret; Parkin, D Maxwell

    2016-03-15

    Data from 20 years of cancer registration in Harare (Zimbabwe) are used to investigate the risk of cancer in the white population of the city (of European origin), relative to that in blacks (of African origin). In the absence of information on the respective populations-at-risk, we calculated odds of each major cancer among all cancers, and took the odds ratios of whites to blacks. Some major differences reflect obvious phenotypic differences (the very high incidence of skin cancer-melanoma and nonmelanoma--in the white population), whereas others (high rates of liver cancer, Kaposi sarcoma and conjunctival cancers in blacks) are the result of differences in exposure to infectious agents. Of particular interest are cancers related to lifestyle factors, and how the differences in risk are changing over time, as a result of evolving lifestyles. Thus, the high risk of cancers of the esophagus and cervix uteri in blacks (relative to whites) and colorectal cancers in whites show little change over time. Conversely, the odds of breast cancer, on average four times higher in whites than blacks, has shown a significant decrease in the differential over time. Cancer of the prostate, with the odds initially (1991-1997) 15% higher in whites had become 33% higher in blacks by 2004-2010. PMID:26437451

  19. Early Childhood Aetiology of Mental Health Problems: A Longitudinal Population-Based Study

    Science.gov (United States)

    Bayer, Jordana K.; Hiscock, Harriet; Ukoumunne, Obioha C.; Price, Anna; Wake, Melissa

    2008-01-01

    Background: Mental health problems comprise an international public health issue affecting up to 20% of children and show considerable stability. We aimed to identify child, parenting, and family predictors from infancy in the development of externalising and internalising behaviour problems by age 3 years. Methods: "Design" Longitudinal,…

  20. 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

  1. 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...

  2. 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…

  3. Black, White and Grey

    Directory of Open Access Journals (Sweden)

    Nasrin Nooshfar

    2011-05-01

    Full Text Available Background/Objective: Development of science and"nart achieved with saving independence, separation"nclassification and studying their details. The other hand"nis combination of these to create a new world with"nwide dimensions and take a place to human needs."nMaterials and Methods: Our attempt is to make"nhealth-care places pleasant and attractive for patients."nWe offer best services, but they are not comfortable"nand happy in these places. They are afraid of the staff,"nequipment and the environment. For this purpose"nwe mixed the brightness and darkness of radiologic"nimages with white and black photographs or paintings"ncomplementary to create analog artistic images that"ncould be converted to digital printing by DICOM"ninterfaces on hard copies."nConclusion: Fear, pictures a bad memory in the"npatient's mind forever. We mixed radiology and"nimaging with photography as a science and art mixture"nto conflict with these problems, it is more effective in"nchildren who are suffering from social and known"ndiseases and can not adapt themselves with their"nsituations. This could create a good memory between"nthe human body image and sentimental experience."nIn the literature, printed radiologic images were used"nas fine art on glass and paper, metal and flowers were"nemployed to mix.* *Wim Delvoye (born 1965 ,Wervik"nand Steven N.Meyers and Merille Raikes

  4. Black, White and Grey

    OpenAIRE

    Nasrin Nooshfar; Jalal Jalal Shokouhi; Shahryar Pashae

    2011-01-01

    Background/Objective: Development of science and"nart achieved with saving independence, separation"nclassification and studying their details. The other hand"nis combination of these to create a new world with"nwide dimensions and take a place to human needs."nMaterials and Methods: Our attempt is to make"nhealth-care places pleasant and attractive for patients."nWe offer best services, but they are not comfortable"nand happy in these places. They are ...

  5. High Serum Irisin Level as an Independent Predictor of Diabetes Mellitus: A Longitudinal Population-Based Study.

    Science.gov (United States)

    Huh, Ji Hye; Ahn, Song Vogue; Choi, Jung Hye; Koh, Sang Baek; Chung, Choon Hee

    2016-06-01

    Irisin, a novel exercise-induced myokine, has been suggested to regulate energy homeostasis and insulin sensitivity. However, it remains unclear whether circulating irisin plays a role in the development of DM in human. We investigated the possible association between circulating irisin levels and incident DM in a 2.6-year longitudinal study of a population-based cohort comprised of rural Korean subjects.We conducted a longitudinal study within the Korean Genome and Epidemiology Study on Atherosclerosis Risk of Rural Areas in the Korean General Population (KoGES-ARIRANG) study from November 2005 to January 2008. Cases (n=85) were patients with incident DM during the follow-up period and controls (n = 85) were matched to incident DM cases based on sex and age at baseline. The relative risk of serum irisin/adiponectin level for incident DM was analyzed using conditional logistic regression analysis.Baseline irisin_ENREF_1 levels were significantly higher in subjects who developed DM than in subjects who did not. The serum irisin level was positively associated with glycated hemoglobin (HbA1c) and postprandial glucose. Irisin was negatively associated with adiponectin (R = -0.189, P = 0.014). After adjustment for potential confounders, including body mass index, the odds ratios [95% confidence intervals] for incident DM increased in a graded manner as the serum irisin level increased (Quartile 1 vs Quartile 2 vs Quartile 3 vs Quartile 4 = 1 vs 0.80 [0.28-2.35] vs 3.33 [1.11-10.00] vs 4.10 [1.35-12.44], respectively), whereas the odds ratios for incident DM decreased in a graded manner as the serum adiponectin level increased.High serum irisin was independently associated with the development of DM, indicating that irisin may be a useful predictor of DM in Korean adults. PMID:27281072

  6. 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

  7. Longitudinal course of mild parkinsonian signs in elderly people: A population-based study in Japan.

    Science.gov (United States)

    Wada-Isoe, Kenji; Tanaka, Kenichiro; Uemura, Yusuke; Nakashita, Satoko; Tajiri, Yuki; Tagashira, Shugo; Yamamoto, Mikie; Yamawaki, Mika; Kishi, Masafumi; Nakashima, Kenji

    2016-03-15

    We aimed to clarify the longitudinal course of mild parkinsonian signs (MPS) and their association with dementia and functional disability by conducting a comprehensive epidemiological study, including brain MRI, and assessments of cognition, depression, and sleep, in people aged ≥65years living in Ama-cho. We diagnosed MPS and parkinsonism (PS) using a modified Unified Parkinson's Disease Rating Scale. The phase I study was conducted between 2008 and 2010 (n=729) and the phase II between 2011 and 2013 (n=436). By phase II, 8.5% of the phase I participants without PS had developed PS. In addition to older age, a lower Mini-Mental State Examination (MMSE) score, and lower body mass index, the MPS rigidity subtype was a significant independent predictor of PS onset. By phase II, 10.1% of the participants without dementia or PS at phase I had developed dementia. Older age, lower MMSE score, and the axial dysfunction and tremor MPS subtypes were significant independent predictors of dementia development. By phase II, 38.8% of participants with MPS at phase I showed no motor symptoms. Younger age and adequate sleep were significant predictors for this reversion. Periventricular and deep white matter hyperintensity Fazekas scores increased with the evolution of parkinsonian signs. MPS is therefore critically, although sometimes reversibly, associated with PS and dementia development in elderly people. PMID:26944110

  8. Parity and 11-Year Serum Thyrotropin and Thyroid Autoantibody Change: A Longitudinal Population-Based Study

    DEFF Research Database (Denmark)

    Bjergved, Lena; Carlé, Allan; Jørgensen, Torben; Perrild, Hans; Laurberg, Peter; Krejbjerg, Anne; Ovesen, Lars; Bülow Pedersen, Inge; Rasmussen, Lone Banke; Knudsen, Nils

    2016-01-01

    thyrotropin (TSH), as well as change in thyroid peroxidase autoantibody (TPOAb) status. A random sample of 4649 people aged 18-65 years participated in a population-based study in the period 1997-1998. In the study presented here, 1749 non-pregnant women with no history of thyroid disease were included who...

  9. 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…

  10. 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…

  11. 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…

  12. Socioeconomic consequences of obesity : Population-based longitudinal studies of Swedish men

    OpenAIRE

    Karnehed, Nina

    2008-01-01

    The overall aim of the thesis was to study if Swedish obese male adolescents become socioeconomicly disadvantaged in later life. Among Swedish men born 1951-79, who went through military conscription examination at age 18-20 years, the associations between obesity and attained education, occupation, income, and disability pension have been studied. The target populations were identified in the Multi-Generation Register. A record linkage was made between this register and...

  13. Childhood behavior problems and academic outcomes in adolescence: longitudinal population-based study

    OpenAIRE

    Sayal, Kapil; Washbrook, Elizabeth; Propper, Carol

    2015-01-01

    Abstract OBJECTIVE: To investigate the impact of increasing levels of inattention, hyperactivity/impulsivity, and oppositional/defiant behaviors at age 7 years on academic achievement at age 16 years. METHOD: In a population-based sample of 7-year-old children in England, information was obtained about inattention, hyperactivity/impulsivity, and oppositional/defiant behaviors (using parent and teacher ratings) and the presence of attention-deficit/hyperactivity disorder (ADHD) a...

  14. Calculation of seed values for longitudinal coupled bunch dipole instability due to uneven bucket population

    International Nuclear Information System (INIS)

    Conventionally, the starting amplitude (or 'seed') for bunched beam coherent oscillations is assumed independent of the steady state Fourier components of the beam, and is attributed to imperfect technology of randomness. However, there are occasions when the dominant component of the seeds derive from the transient response of the impedance to the revolution harmonics. Such harmonics are caused by uneven bucket population. In this paper we find the beam response to sweeping the radio frequency through a cavity parasitic resonance in order to calculate the increases in the individual bunch dipole moments and the coupled-bunch oscillation amplitude. In the KAON Booster, an hypothetical first HOM with Q = 4000 and R/Q = 30 gives a coupled-bunch dipole oscillation of 27 degrees of rf phase; which would swamp any injection timing errors. (Author) 4 refs

  15. A Longitudinal Analysis of Mosquito Net Ownership and Use in an Indigenous Batwa Population after a Targeted Distribution.

    Science.gov (United States)

    Clark, Sierra; Berrang-Ford, Lea; Lwasa, Shuaib; Namanya, Didacus; Twesigomwe, Sabastian; Kulkarni, Manisha

    2016-01-01

    Major efforts for malaria prevention programs have gone into scaling up ownership and use of insecticidal mosquito nets, particularly in sub-Saharan Africa where the malaria burden is high. Socioeconomic inequities in access to long lasting insecticidal nets (LLINs) are reduced with free distributions of nets. However, the relationship between social factors and retention of nets after a free distribution has been less studied, particularly using a longitudinal approach. Our research aimed to estimate the ownership and use of LLINs, and examine the determinants of LLIN retention, within an Indigenous Batwa population after a free LLIN distribution. Two LLINs were given free of charge to each Batwa household in Kanungu District, Uganda in November 2012. Surveyors collected data on LLIN ownership and use through six cross-sectional surveys pre- and post-distribution. Household retention, within household access, and individual use of LLINs were assessed over an 18-month period. Socioeconomic determinants of household retention of LLINs post-distribution were modelled longitudinally using logistic regression with random effects. Direct house-to-house distribution of free LLINs did not result in sustainable increases in the ownership and use of LLINs. Three months post-distribution, only 73% of households owned at least one LLIN and this period also saw the greatest reduction in ownership compared to other study periods. Eighteen-months post distribution, only a third of households still owned a LLIN. Self-reported age-specific use of LLINs was generally higher for children under five, declined for children aged 6-12, and was highest for older adults aged over 35. In the model, household wealth was a significant predictor of LLIN retention, controlling for time and other variables. This research highlights on-going socioeconomic inequities in access to malaria prevention measures among the Batwa in southwestern Uganda, even after free distribution of LLINs, and

  16. Childhood ADHD and risk for substance dependence in adulthood: a longitudinal, population-based study.

    Directory of Open Access Journals (Sweden)

    Sharon Levy

    Full Text Available Adolescents with attention-deficit/hyperactivity disorder (ADHD are known to be at significantly greater risk for the development of substance use disorders (SUD compared to peers. Impulsivity, which could lead to higher levels of drug use, is a known symptom of ADHD and likely accounts, in part, for this relationship. Other factors, such as a biologically increased susceptibility to substance dependence (addiction, may also play a role.This report further examines the relationships between childhood ADHD, adolescent- onset SUD, and substance abuse and substance dependence in adulthood.Individuals with childhood ADHD and non-ADHD controls from the same population-based birth cohort were invited to participate in a prospective outcome study. Participants completed a structured neuropsychiatric interview with modules for SUD and a psychosocial questionnaire. Information on adolescent SUD was obtained retrospectively, in a previous study, from medical and school records. Associations were summarized using odds ratios (OR and 95% CIs estimated from logistic regression models adjusted for age and gender.A total of 232 ADHD cases and 335 non-ADHD controls participated (mean age, 27.0 and 28.6 years, respectively. ADHD cases were more likely than controls to have a SUD diagnosed in adolescence and were more likely to have alcohol (adjusted OR 14.38, 95% CI 1.49-138.88 and drug (adjusted OR 3.48, 95% CI 1.38-8.79 dependence in adulthood. The subgroup of participating ADHD cases who did not have SUD during adolescence were no more likely than controls to develop new onset alcohol dependence as adults, although they were significantly more likely to develop new onset drug dependence.Our study found preliminary evidence that adults with childhood ADHD are more susceptible than peers to developing drug dependence, a disorder associated with neurological changes in the brain. The relationship between ADHD and alcohol dependence appears to be more complex.

  17. 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

  18. 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...

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

    OpenAIRE

    Akinyemiju, Tomi F.; Soliman, Amr S.; Johnson, Norman J.; Altekruse, Sean F.; Kathy Welch; Mousumi Banerjee; Kendra Schwartz; Sofia Merajver

    2013-01-01

    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 ...

  20. 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

  1. 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.

  2. 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.

  3. Relative deprivation and mortality – a longitudinal study in a Swedish population of 4,7 million, 1990–2006

    Directory of Open Access Journals (Sweden)

    Åberg Yngwe Monica

    2012-08-01

    Full Text Available Abstract Background Relative deprivation has previously been discussed as a possible mechanism underlying the income-health relation. The idea is that income matters to the individual’s health, over and above the increased command over resources, as the basis of social comparisons between a person and his or her reference group. The following study aimed to analyze the role of individual-level relative deprivation for all-cause mortality in the Swedish population. The Swedish context, characterized by relatively small income inequalities and promoting values as egalitarianism and equality, together with a large data material provide unique possibilities for analyzing the hypothesized mechanism. Methods The data used are prospective longitudinal data from the Swedish population and based on a linkage of registers. Restricting selection to individuals 25–64 years, alive January 1st 1990, gave 4.7 million individuals, for whom a mortality follow-up was done over a 16-year period. The individual level relative deprivation was measured using the Yitzhaki index, calculating the accumulated shortfall between the individual’s income and the income of all other’s in the person’s reference group. All-cause mortality was used as the outcome measure. Results Relative deprivation, generated through social comparisons, is one possible mechanism within the income and health relation. The present study analyzed different types of objectively defined reference groups, all based on the idea that people compare themselves to similar others. Results show relative deprivation, when measured by the Yitzhaki index, to be significantly associated with mortality. Also, we found a stronger effect among men than among women. Analyzing the association within different income strata, the effect was shown to be weak among the poorest. Revealing the importance of relative deprivation for premature mortality, over and above the effect of absolute income, these

  4. 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

  5. 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

  6. 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.

  7. Teachers' perceptions of the effectiveness of an urban health sciences curriculum in closing the Black-White test score gap: A participatory case study

    Science.gov (United States)

    Prince, Joan Marie

    1999-12-01

    Over the past years, progress in Black academic achievement, particularly in the area of science, has generally slowed or ceased. According to the 1994 NAEP assessment, twelfth-grade Black students are performing at the level of White eighth-grade students in the discipline of science (Department of Education, 1996). These students, in their last year of required schooling, are about to graduate, yet they lag at least four years behind their white counterparts in science achievement. Despite the establishment and implementation of numerous science intervention programs, Black students still suffer from a disparate gap in standardized test score achievement. The purpose of this research is to investigate teachers' perceptions of the effectiveness of an urban sciences intervention tool that was designed to assist in narrowing the Black-White science academic achievement gap. Specifically, what factors affect teachers' personal sense of instructional efficacy, and how does this translate into their outcome expectancy for student academic success? A multiple-case, replicative design, grounded in descriptive theory, was selected for the study. Multiple sources of evidence were queried to provide robust findings. These sources included a validated health sciences self-efficacy instrument, an interview protocol, a classroom observation, and a review of archival material that included case study participants' personnel files and meeting minutes. A cross-comparative analytic approach was selected for interpretation (Yin, 1994). Findings indicate that teachers attribute the success or failure of educational intervention tools in closing the Black-White test score gap to a variety of internal and external factors. These factors included a perceived lack of both monetary and personal support by the school leadership, as well as a perceived lack of parental involvement which impacted negatively on student achievement patterns. The case study participants displayed a depressed

  8. 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.

  9. 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

  10. Ossification of the posterior longitudinal ligament in three geographically and genetically different populations of ankylosing spondylitis and other spondyloarthropathies

    OpenAIRE

    Ramos-Remus, C.; Russell, A.; Gomez-Vargas, A.; Hernandez-Chavez, A.; Maksymowych, W.; Gamez-Nava, J.; Gonzalez-Lopez, L.; Garcia-Hernandez, A.; Meono-Morales, E.; Burgos-Vargas, R; Suarez-Almazor, M.

    1998-01-01

    STUDY DESIGN—Cross sectional.
RESEARCH QUESTIONS—(a) Is any clinical variable of ankylosing spondylitis (AS) associated with the presence of ossification of the posterior longitudinal ligament (OPLL)? and (b) Is OPLL present in patients with AS from different geographical or genetic backgrounds?
METHODS—Three groups were assembled: (1) a prospective group of 103 consecutive AS patients from two community based rheumatology clinics from Guadalajara, who were evaluated using: a questionnaire wi...

  11. 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 ...

  12. 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 ...

  13. 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

  14. 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.

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

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    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

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

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    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.

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

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    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.

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

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    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

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

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    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.

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

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    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.

  1. 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…

  2. 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

  3. Dietary patterns among the Metro Atlanta Cohort: implications for population-based longitudinal dietary pesticide exposure and risk assessment.

    Science.gov (United States)

    Riederer, Anne M; Pearson, Melanie A; Lu, Chensheng

    2011-01-01

    Characterizing dietary consumption patterns is critical to dietary pesticide exposure assessment. We compared consumption patterns between adults (age 18-60) in the Metro Atlanta Cohort (MAC), a longitudinal study of pesticide exposure among Atlanta residents, and US National Health and Nutrition Examination Survey (NHANES) adults. We focused on foods commonly eaten by US adults and foods likely to contain certain pesticide residues. MAC participants provided consumption data for 6 days per month for 1 year using a web-based data collection tool. We defined "percent eaters" as the percent of participants who reported eating a particular food in 24 h. We computed the NHANES weighted percent eaters and 95% confidence limits (CLs) using the 24-h dietary recall data. We calculated the MAC percent eaters for each sampling day and the percent of days this number fell below, within, or above the NHANES 95% CLs. We also re-sampled the MAC percent eaters across sampling days to find whether the resulting distribution resembled the NHANES estimate, and used the Kruskal-Wallis test to evaluate whether season affected the number of MAC eaters of a particular food on a given sampling day. In general, across all sampling days, a greater proportion of MAC participants reported eating banana, broccoli, cream, grapes, lettuce, onion, peach, pear, peas, strawberries, string beans, and tomatoes than the national estimate, whereas the proportion of apple, spinach, ketchup and white bread/roll eaters was similar, and the proportion of milk drinkers was lower. Season predicted the number of MAC peach and strawberry eaters but not other foods. The data show how a higher proportion of Atlanta adults may eat certain foods (e.g., peaches in summer or strawberries in spring) than the national average depending on season or other factors. An exposure assessment that ignored this difference could underestimate dietary pesticide intakes. PMID:20354565

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

    OpenAIRE

    Steenbeek Romy

    2012-01-01

    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 ...

  5. 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

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    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

  6. Multiple births and maternal mental health from pregnancy to 5 years after birth: a longitudinal population-based cohort study

    OpenAIRE

    Eivind Ystrom; Ted Reichborn-Kjennerud; Kristian Tambs; Per Magnus; Anne Mari Torgersen; Kristin Gustavson

    2014-01-01

    Background: There is a lack of population-based studies on multiple births and maternal mental health. Having a high-risk pregnancy by bearing two or more children is a stressful life event, and the challenges of parenting two or more children probably also lead to a high level of parental stress. There are a few results on multiple births and maternal mental health from studies on in vitro fertilization samples. The only previous cohort study on multiple birth and maternal mental health incl...

  7. 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

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

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    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

  9. 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

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    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.

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

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    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.

  11. Multiple births and maternal mental health from pregnancy to 5 years after birth: A longitudinal population-based cohort study

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    Eivind Ystrom

    2014-12-01

    Full Text Available Background: There is a lack of population-based studies on multiple births and maternal mental health. Having a high-risk pregnancy by bearing two or more children is a stressful life event, and the challenges of parenting two or more children probably also lead to a high level of parental stress. There are a few results on multiple births and maternal mental health from studies on in vitro fertilization samples. The only previous cohort study on multiple birth and maternal mental health included a single measure of depressive symptoms at 9 months postpartum. We aim to estimate the relative risk for depression and anxiety after multiple birth in a population-based prospective cohort study while adjusting for factors prior and subsequent to fertilization.Methods: We used data from 87,807 pregnancies included in the Norwegian Mother and Child Cohort study. Information on multiple birth was retrieved from the Norwegian Medical Birth Registry, and maternal mental health was assessed at 17th and 30th week of gestation and 0.5, 1.5, 3, and 5 years postpartum. There were 1,842 plural births included in the study (i.e. 1,821 twin births and 21 higher order births. We predicted maternal mental health at each time point, subsequently adjusting for 1 factors prior to fertilization (e.g. maternal age and in vitro fertilization; 2 factors during pregnancy (e.g. hypertensive states; 3 factors at delivery (e.g. cesarean section; 4 child-related postnatal complications (e.g. intracranial hemorrhage; and 5 concurrent depression or anxiety after pregnancy.Results: Adjusted for antecedents of plural birth, mothers expecting a plural birth had a normal risk for anxiety (RR=1.05; 95% CI 0.92-1.20 and depression (RR=1.02; 95% CI 0.89-1.16 at 17th week of gestation. However, plural birth was associated with maternal depression at 1.5, 3, and 5 years postpartum and maternal anxiety at 3 years postpartum. The trend was for the association to increase across time, and

  12. 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

  13. Health service utilisation for anogenital warts in Ontario, Canada prior to the human papillomavirus (HPV) vaccine programme introduction: a retrospective longitudinal population-based study

    Science.gov (United States)

    Guerra, Fiona M; Rosella, Laura C; Dunn, Sheila; Wilson, Sarah E; Chen, Cynthia; Deeks, Shelley L

    2016-01-01

    Objective Trends in occurrence of anogenital warts (AGWs) can provide early evidence of human papillomavirus (HPV) vaccination programme impact on preventing HPV infection and HPV-induced lesions. The objective of this study was to provide a baseline of AGW epidemiology in Ontario prior to the introduction of the publicly-funded school-based HPV vaccination programme in September 2007. Setting and participants As a retrospective longitudinal population-based study, we used health administrative data as a proxy to estimate incident AGWs and total health service utilisation (HSU) for AGWs for all Ontario residents 15 years and older with valid health cards between 1 April 2003 and 31 March 2007. Outcome measures The outcome of interest was AGW healthcare utilisation identified using the International Classification of Diseases, 10th revision (ICD-10) diagnostic code for AGWs, as well as an algorithm for identifying AGW physician office visits in a database with a unique system of diagnostic and procedural codes. An AGW case was considered incident if preceded by 12 months without HSU for AGWs. Time trends by age group and sex were analysed. Results Between fiscal years 2003 and 2006, we identified 123 247 health service visits for AGWs by 51 436 Ontario residents 15 years and older. Incident AGWs peaked in females and males in the 21–23 year age group, at 3.74 per 1000 and 2.81 per 1000, respectively. HSU for AGWs peaked in females and males within the 21–23 year age group, at 9.34 per 1000 and 7.22 per 1000, respectively. Conclusions To the best of our knowledge, this is the first population-based study of AGW incidence and HSU in Ontario. The sex and age distribution of individuals with incident and prevalent AGWs in Ontario was similar to that of other provinces before HPV vaccine programme implementation in Canada. PMID:26966057

  14. Racial Disparities in Diabetes Mortality in the 50 Most Populous US Cities

    OpenAIRE

    Rosenstock, Summer; Whitman, Steve; West, Joseph F.; Balkin, Michael

    2014-01-01

    While studies have consistently shown that in the USA, non-Hispanic Blacks (Blacks) have higher diabetes prevalence, complication and death rates than non-Hispanic Whites (Whites), there are no studies that compare disparities in diabetes mortality across the largest US cities. This study presents and compares Black/White age-adjusted diabetes mortality rate ratios (RRs), calculated using national death files and census data, for the 50 most populous US cities. Relationships between city-leve...

  15. 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,...

  16. 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.

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    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.

  17. 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

  18. 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

  19. 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

  20. 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

    BACKGROUND: Adiposity has been linked to both higher risk of asthma and reduced lung function. The effects of adiposity on asthma may depend on both atopic status and gender, while the relationship is less clear with respect to lung function. This study aimed to explore longitudinal weight changes...

  1. Declining Sleep Quality among Nurses: A Population-Based Four-Year Longitudinal Study on the Transition from Nursing Education to Working Life

    OpenAIRE

    Hasson, Dan; Gustavsson, Petter

    2010-01-01

    Background Several studies have established impaired sleep is a common problem among nurses. Overworked, fatigued and stressed nurses are at a higher risk of making mistakes that threaten patient safety as well as their own health. The aim of the present study was to longitudinally monitor the development of sleep quality in nurses, starting from the last semester at the university, with three subsequent annual follow-ups once the nurses had entered working life. Methodology/Principal Finding...

  2. 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

  3. 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

  4. Declining sleep quality among nurses: a population-based four-year longitudinal study on the transition from nursing education to working life.

    Directory of Open Access Journals (Sweden)

    Dan Hasson

    Full Text Available BACKGROUND: Several studies have established impaired sleep is a common problem among nurses. Overworked, fatigued and stressed nurses are at a higher risk of making mistakes that threaten patient safety as well as their own health. The aim of the present study was to longitudinally monitor the development of sleep quality in nurses, starting from the last semester at the university, with three subsequent annual follow-ups once the nurses had entered working life. METHODOLOGY/PRINCIPAL FINDINGS: Nationwide, longitudinal questionnaire study of nursing students and newly qualified nurses in Sweden. The results imply a continuous decline in sleep quality among nurses during the three years of follow-up, starting from their last semester of nursing education and continuing for three years into their working life. The most pronounced short-term decline in sleep quality seems to occur in the transition between student life and working life. CONCLUSION/SIGNIFICANCE: This finding is important since it may affect the quality of care and the health of nurses negatively.

  5. ¿POR QUÉ AUMENTA LA POBLACIÓN PENAL EN CHILE?: UN ESTUDIO CRIMINOLÓGICO LONGITUDINAL ¿Why is criminal population increasing in Chile?: a longitudinal criminology study

    Directory of Open Access Journals (Sweden)

    Sebastián Salinero Echeverría

    2012-01-01

    Full Text Available En este trabajo se analizan los factores y las respectivas causas del incremento de la población carcelaria en Chile entre el período 2000-2009. Se consigna que los factores que producirían la inflación penitenciaria son atribuibles al mayor ingreso de personas al sistema penal; al mayor tiempo de privación de libertad de los penados, y a la falta de mecanismos reales de descompresión carcelaria. A su vez, se analizan las causas que probablemente originarían estos factores, tales como la Reforma Procesal Penal y todo lo que ella introdujo desde la perspectiva de un nuevo sistema de administración de justicia penal; el punitivismo penal, con leyes que favorecerían la prisionización, y un marcado reduccionismo en los denominados beneficios legales alternativos a la prisión.In this paper the author analyzes the factors and causes of the increase in prison population in Chile between 2000 and 2009. It is stated that the factors that cause a rise in prison population are attributable to an increased inflow of people into the criminal system, to a longer incarceration of prisoners, and, to a lack of real mechanisms of prison reduction. In turn, the causes that are likely to originate these factors are analyzed, such as the Criminal Procedure Reform and everything it brought from the perspective of a new system of criminal justice, the punitive criminal justice that favor incarceration, and a marked reduction in legal benefits known as alternatives to prison.

  6. No evidence of association between blastocyst aneuploidy and morphokinetic assessment in a selected population of poor-prognosis patients: a longitudinal cohort study.

    Science.gov (United States)

    Rienzi, L; Capalbo, A; Stoppa, M; Romano, S; Maggiulli, R; Albricci, L; Scarica, C; Farcomeni, A; Vajta, G; Ubaldi, F M

    2015-01-01

    Recent studies involving a limited number of patients have indicated a correlation between aneuploidy and various morphokinetic parameters during preimplantation development. The results among different groups, however, have been inconsistent in identifying the parameters that are able to predict chromosomal abnormalities. The aim of this study was to investigate whether aneuploidy of human blastocysts was detectable by specific morphokinetic parameters in patients at increased risk of aneuploidy because of advanced maternal age, history of unsuccessful IVF treatments, or both. A longitudinal cohort study was conducted using 455 blastocysts from 138 patients. Morphokinetic features of preimplantation development were detected in a timelapse incubator. Blastocysts were subjected to trophectodermal biopsy and comprehensive chromosomal screening. Analyses were conducted by means of logistic mixed-effects models, with a subject-specific intercept. No statistical correlation between 16 commonly detected morphokinetic characteristics of in-vitro embryo development and aneuploidy was found. Results suggest that morphokinetic characteristics cannot be used to select euploid blastocysts in poor-prognosis patients regarded as candidates for pre-implantation genetic screening. PMID:25458852

  7. 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

  8. 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...

  9. Black&White [Pròleg

    OpenAIRE

    Sánchez Durá, Nicolás

    2014-01-01

    Este libro analiza los distintos usos de la fotografía en el periodo clásico de la Antropología en el que se constituyó la autoridad etnográfica. Usos que no solo refieren al trabajo de campo de los etnógrafos, sino también a la posterior circulación de las imágenes fotográficas en publicaciones, museos y archivos. Centrado en el arranque de la tradición africanista francesa (M. Griaule, M. Leiris…), el autor no olvida en su análisis comparativo a los pioneros del medio académico anglo-sajón ...

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

    OpenAIRE

    Ribeiro Manoel CSA; Matsudo Sandra MM; Ferreira Marcela T; Ramos Luiz R

    2010-01-01

    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 ...

  11. 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...

  12. 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

  13. 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.

  14. Predictors of five-year functional ability in a longitudinal survey of men and women aged 75 to 80. The 1914-population in Glostrup, Denmark

    DEFF Research Database (Denmark)

    Schroll, M; Avlund, K; Davidsen, M

    mobility functions. "Stability" in mobility functions was related to ability to mount stairs, walking speed, mood and physical activity. Number of chronic diseases and low pulmonary function were only related to mobility in men. Among people who improved their function, many had rather low baseline...... strength. In women only low physical activity was predictive (RR = 4.32). From baseline to follow-up, 34% of the population had reduced their physical activities. Knee extension strength was reduced from 6.0 to 4.4 N/kg in men, and from 4.2 to 3.3 N/kg in women. In the stair-mounting test, 44% could only...

  15. 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

  16. 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

  17. 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.

  18. 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

  19. Longitudinal, Whole-population Data Examining Pathways of Risk from Conception to Disease: The Western Australian Schizophrenia High-risk e-Cohort

    Directory of Open Access Journals (Sweden)

    Vera A. Morgan

    2014-09-01

    Full Text Available This database has been constructed to support a program of work designed to untangle genetic and environmental contributions to the risk for schizophrenia and other adverse outcomes in the offspring of mothers with schizophrenia and other severe mental illness. To do this, it utilises Western Australian whole-population health and social services databases. Records on the Western Australian psychiatric case register have been linked to Midwives’ Notification of Birth records and to Registrations of Births (for paternal links as well as to other data sets. Maternal links identify women with psychosis who gave birth in Western Australia between 1980 and 2001. Comparison mothers are those with no record of psychiatric illness who gave birth in Western Australia over the same period. The study database comprises 246,873 mothers and 467,945 children: 889 mothers with schizophrenia (1,672 children; 1,644 mothers with bipolar disorder (3,358 children; 4,200 mothers with unipolar major depression (8,864 children; 775 mothers with other psychoses (1,592 children; and 239,365 comparison mothers (452,459 children. Full psychiatric histories for mothers, fathers and children have been extracted. At the time of the most recent update to the psychiatric data on children, 33,363 children had a history of psychiatric illness; 5,500 of these had had at least one contact with mental health services at which a diagnosis of a psychotic disorder had been recorded. Data have also been collected on obstetric complications and a range of infant and childhood morbidities including birth defects, intellectual disability, educational achievement, childhood abuse, criminal offending.The program aims are to: (i determine the frequency and distribution of obstetric complications in women with schizophrenia compared to a non-psychiatric comparison group of mothers; (ii explore the spectrum of outcomes for the children born to women with schizophrenia compared to comparison

  20. Longitudinal, Whole-population Data Examining Pathways of Risk from Conception to Disease: The Western Australian Schizophrenia High-risk e-Cohort

    Directory of Open Access Journals (Sweden)

    Vera A. Morgan

    2014-09-01

    Full Text Available This database has been constructed to support a program of work designed to untangle genetic and environmental contributions to the risk for schizophrenia and other adverse outcomes in the offspring of mothers with schizophrenia and other severe mental illness. To do this, it utilises Western Australian whole-population health and social services databases. Records on the Western Australian psychiatric case register have been linked to Midwives’ Notification of Birth records and to Registrations of Births (for paternal links as well as to other data sets. Maternal links identify women with psychosis who gave birth in Western Australia between 1980 and 2001. Comparison mothers are those with no record of psychiatric illness who gave birth in Western Australia over the same period. The study database comprises 246,873 mothers and 467,945 children: 889 mothers with schizophrenia (1,672 children; 1,644 mothers with bipolar disorder (3,358 children; 4,200 mothers with unipolar major depression (8,864 children; 775 mothers with other psychoses (1,592 children; and 239,365 comparison mothers (452,459 children. Full psychiatric histories for mothers, fathers and children have been extracted. At the time of the most recent update to the psychiatric data on children, 33,363 children had a history of psychiatric illness; 5,500 of these had had at least one contact with mental health services at which a diagnosis of a psychotic disorder had been recorded. Data have also been collected on obstetric complications and a range of infant and childhood morbidities including birth defects, intellectual disability, educational achievement, childhood abuse, criminal offending. The program aims are to: (i determine the frequency and distribution of obstetric complications in women with schizophrenia compared to a non-psychiatric comparison group of mothers; (ii explore the spectrum of outcomes for the children born to women with schizophrenia compared to comparison

  1. Longitudinal study on osteoarthritis and bone metabolism

    OpenAIRE

    L Postiglione; Savastano, S; A. Scognamiglio; G. Nutile; Carpinelli, A; Esposito, A.; del Puente, A; Padula, S.; Oriente, P

    2011-01-01

    Objective: The relationship between Osteoarthritis (OA) and Osteoporosis (OP) is not well defined due to lacking in longitudinal data, mainly regarding correlations between biochemical factors and OA incidence. Aim of this paper was to investigate the predictive value for OA incidence of bone mass variations and of selected biochemical markers in healthy women participating in a population-based longitudinal study carried out in Naples (Italy). Subjects and Methods: High completion rate (85.2...

  2. 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

  3. Restoration of longitudinal images.

    Science.gov (United States)

    Hu, Y; Frieden, B R

    1988-01-15

    In this paper, a method of restoring longitudinal images is developed. By using the transfer function for longitudinal objects, and inverse filtering, a longitudinal image may be restored. The Fourier theory and sampling theorems for transverse images cannot be used directly in the longitudinal case. A modification and reasonable approximation are introduced. We have numerically established a necessary relationship between just-resolved longitudinal separation (after inverse filtering), noise level, and the taking conditions of object distance and lens diameter. An empirical formula is also found to well-fit the computed results. This formula may be of use for designing optical systems which are to image longitudinal details, such as in robotics or microscopy. PMID:20523607

  4. 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

  5. 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 ...

  6. Longitudinal impedance of RHIC

    International Nuclear Information System (INIS)

    The longitudinal impedance of the two RHIC rings has been measured using the effect of potential well distortion on longitudinal Schottky measurements. For the blue RHIC ring Im(Z/n) = 1.5±0.2?. For the yellow ring Im(Z/n) = 5.4±1?.

  7. 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...

  8. Longitudinal Beam Dynamics

    OpenAIRE

    Tecker, F.

    2016-01-01

    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.

  9. 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.

  10. 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...

  11. 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...

  12. Longitudinal Lisfranc injury.

    Science.gov (United States)

    Oak, Nikhil R; Manoli, Arthur; Holmes, James R

    2014-01-01

    Most Lisfranc or tarsometatarsal (TMT) joint injuries result from a horizontally directed force in which the metatarsals are displaced relative to the midfoot. The injury pattern that is described in this article is one of a longitudinal force through the first ray and cuneiform. A reliable measure to recognize the longitudinal Lisfranc variant injury has been the height difference between the distal articular surfaces of the first and second cuneiform bones in an anteroposterior (AP) weight-bearing radiograph. This measure helps identify subtle injuries in which there is a proximal and medial subluxation of the first cuneiform-metatarsal complex. Delayed diagnosis and treatment have been associated with poorer results and significant functional consequences. This article describes a simple radiographic measurement to recognize the longitudinal injury pattern and to aid in determining whether operative intervention is required. PMID:25785475

  13. Allergies and major depression: a longitudinal community study

    OpenAIRE

    Lavorato Dina H; Williams Jeanne VA; Patten Scott B; Eliasziw Michael

    2009-01-01

    Abstract Background Cross-sectional studies have reported associations between allergies and major depression but in the absence of longitudinal data, the implications of this association remain unclear. Our goal was to examine this association from a longitudinal perspective. Methods The data source was the Canadian National Population Health Survey (NPHS). This study included a short form version of the Composite International Diagnostic Interview (CIDI-SF) to assess major depression and al...

  14. Summary Statistics of Neutral Mutations in Longitudinal DNA Samples

    OpenAIRE

    Liu, Xiaoming; Fu, Yun-Xin

    2008-01-01

    Longitudinal samples of DNA sequences are the DNA sequences sampled from the same population at different time points. For fast evolving organisms, e.g. RNA virus, these kind of samples have increasingly been used to study the evolutionary process in action. Longitudinal samples provide some interesting new summary statistics of genetic variation, such as the frequency of mutation of size i in one sample and size j in another, the average number of mutations accumulated since the common ances...

  15. Elaboração e validação de intervalos de referência longitudinais de peso fetal com uma amostra da população brasileira Elaboration and validation of longitudinal reference intervals of fetal weight with a sample of the Brazilian population

    Directory of Open Access Journals (Sweden)

    Érica Luciana de Paula Furlan

    2012-10-01

    Full Text Available OBJETIVOS: Elaborar modelos de predição de peso fetal e de percentis longitudinais de peso fetal estimado (PFE com uma amostra da população brasileira. MÉTODOS: Estudo observacional prospectivo. Dois grupos de gestantes foram recrutados: Grupo EPF (estimativa de peso fetal: pacientes para elaboração (EPF-El e validação (EPF-Val de um modelo de predição de peso fetal; Grupo IRL (intervalos de referência longitudinais: gestantes para elaboração (IRL-El e validação (IRL-Val de intervalos de referência longitudinais de PFE. Regressão polinomial foi utilizada com os dados do subgrupo EPF-El para gerar o modelo de predição de peso fetal. O desempenho deste modelo foi comparado com os de outros disponíveis na literatura. Modelos lineares mistos foram usados para elaboração de intervalos longitudinais de PFE com os dados do subgrupo IRL-El. Os dados do subgrupo IRL-Val foram usados para validação destes intervalos. RESULTADOS: Quatrocentos e cinqüenta e oito pacientes compuseram o Grupo EPF (EPF-El: 367; EPF-Val: 91 e 315 o Grupo IRL (IRL-El: 265; IRL-Val: 50. A fórmula para cálculo do PFE foi: PFE=-8,277+2,146xDBPxCAxCF-2,449xCFxDBP². Os desempenhos de outras fórmulas para estimativa de peso fetal em nossa amostra foram significativamente piores do que os do modelo gerado neste estudo. Equações para predição de percentis condicionais de PFE foram derivadas das avaliações longitudinais do subgrupo IRL-El e validadas com os dados do subgrupo IRL-Val. CONCLUSÕES: descrevemos um método para adaptação de intervalos de referência longitudinais de PFE, sendo este obtido por meio de fórmulas geradas em uma amostra da população brasileira.PURPOSES: To elaborate models for the estimation of fetal weight and longitudinal reference intervals of estimated fetal weight (EFW using a sample of the Brazilian population. METHODS: Prospective observational study. Two groups of patients were evaluated: Group EFW (estimation of

  16. 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

  17. Longitudinal microwave instability

    International Nuclear Information System (INIS)

    A derivation of the relationship between growth rate and impedance is given. The only other instability considered here is the resonance effect produced by excessive tune shift due to space charge. We assume, without discussion, the (Δν)/sub max/ = .25; that is, this resonance growth is avoided (stability) by limiting the ring charge. On the other hand, the longitudinal microwave instability is assumed to be present (cannot be stabilized). Thus, the latter involves a limiting impedance to keep the growth rate low enough. The maximum allowed impedance for a maximum allowed growth rate is listed

  18. 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

  19. 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

  20. Quality of reporting of observational longitudinal research.

    Science.gov (United States)

    Tooth, Leigh; Ware, Robert; Bain, Chris; Purdie, David M; Dobson, Annette

    2005-02-01

    Observational longitudinal research is particularly useful for assessing etiology and prognosis and for providing evidence for clinical decision making. However, there are no structured reporting requirements for studies of this design to assist authors, editors, and readers. The authors developed and tested a checklist of criteria related to threats to the internal and external validity of observational longitudinal studies. The checklist criteria concerned recruitment, data collection, biases, and data analysis and descriptive issues relevant to study rationale, study population, and generalizability. Two raters independently assessed 49 randomly selected articles describing stroke research published from 1999 to 2003 in six journals: American Journal of Epidemiology, Journal of Epidemiology and Community Health, Stroke, Annals of Neurology, Archives of Physical Medicine and Rehabilitation, and American Journal of Physical Medicine and Rehabilitation. On average, 17 of the 33 checklist criteria were reported. Criteria describing the study design were better reported than those related to internal validity. No relation was found between study type (etiologic or prognostic) or word count and quality of reporting. A flow diagram for summarizing participant flow through a study was developed. Editors and authors should consider using a checklist and flow diagram when reporting on observational longitudinal research. PMID:15671260

  1. 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...

  2. 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....

  3. 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

  4. 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…

  5. 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...

  6. 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…

  7. 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…

  8. The Reality of Longitudinal Data Collection: Locating Vanishing Veterans.

    Science.gov (United States)

    Camara, Wayne J.; And Others

    This paper investigates the utility of various procedures used to locate and interview veterans as part of a longitudinal research study being conducted for the Department of Defense. The populations are comprised of below entry aptitude standards males who entered the military during the late 1960s, and potentially ineligibles who entered between…

  9. Criminal Victimization and Crime Risk Perception: A Multilevel Longitudinal Study

    Science.gov (United States)

    Russo, Silvia; Roccato, Michele; Vieno, Alessio

    2013-01-01

    In a national sample of the Italian population, surveyed four times between October 2002 and January 2007 (N = 2,008), we performed a multilevel longitudinal study aimed at predicting the increase in crime risk perception as a function of three families of independent variables, respectively lying at the within individual level (direct…

  10. 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.

  11. "Old Age and Loneliness: Cross-Sectional and Longitudinal Analyses in the Tampere Longitudinal Study on Aging"

    Science.gov (United States)

    Jylha, Marja

    2004-01-01

    The purpose of this study was to examine whether older age is associated with increasing loneliness in people aged 60 and over. Data came from TamELSA, a population-based prospective longitudinal study in Tampere, Finland. The followup time was 20 years. Loneliness was measured by a single question--"Do you feel lonely?"--with the possible answers…

  12. 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.

  13. 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...

  14. 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; Mogensen, Ulrik Madvig; Waziri, Homa; Møller, Jacob Eifer; Hassager, Christian; Søgaard, Peter; Køber, Lars

    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....

  15. 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 ...

  16. 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

  17. 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...

  18. Longitudinal motion in circular accelerators

    International Nuclear Information System (INIS)

    A general description is given of the longitudinal motion of an idealized synchronous particle, exactly in step with the radiofrequency field of a circular accelerator, and a domain in phase and energy, called a bucket, around this particle within which particles are focused around the synchronous particle. This general picture is then made more precise and quantitative. The equations of longitudinal motion and their solutions and the resulting motion are discussed, followed by applications and amplication of the theory. 7 refs., 8 figs

  19. 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

  20. Longitudinal study on osteoarthritis and bone metabolism

    Directory of Open Access Journals (Sweden)

    L. Postiglione

    2011-09-01

    Full Text Available Objective: The relationship between Osteoarthritis (OA and Osteoporosis (OP is not well defined due to lacking in longitudinal data, mainly regarding correlations between biochemical factors and OA incidence. Aim of this paper was to investigate the predictive value for OA incidence of bone mass variations and of selected biochemical markers in healthy women participating in a population-based longitudinal study carried out in Naples (Italy. Subjects and Methods: High completion rate (85.2% and statistically adequate sample size were obtained: 139 women (45 to 79 years of age were examined and follow up visit was performed after two years (24±2 months, following the same protocol. Patients underwent medical examination, questionnaire, anthropometric measurements, blood sampling and urine collection. Bone mineral density (BMD measurement was performed by dual energy X-ray absorptiometry (DEXA at the lumbar spine (L1-L4 and femoral neck. Radiographs of dorsal and lumbar spine in lateral view were performed at basal and at 24 months visits; a team of three experts scored radiographs using Kellegren and Lawrence grading. Results: The score was calculated for two individual radiographic features (narrowing of the joint space, presence of osteophytes and as a global score. Results show a relevant percentage, 23% up, of subjects presenting both OA and OP. In the cross-sectional study the presence of osteophytosis correlates with anthropometric variables and PTH levels. In the longitudinal study results show a correlation between serum vitamin D and delta score for osteophytosis (β=0.02 p<0.05. Conclusions: Data obtained outline the importance of further studies on the pathogenetic link between OA and bone metabolism.

  1. 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

  2. Summary of longitudinal instabilities workshop

    Energy Technology Data Exchange (ETDEWEB)

    Chasman, R.

    1976-01-01

    A five-day ISABELLE workshop on longitudinal instabilities was held at Brookhaven, August 9-13, 1976. About a dozen outside accelerator experts, both from Europe and the U.S.A., joined the local staff for discussions of longitudinal instabilities in ISABELLE. An agenda of talks was scheduled for the first day of the workshop. Later during the week, a presentation was given on the subject ''A more rigorous treatment of Landau damping in longitudinal beam instabilities''. A few progress meetings were held in which disagreements regarding calculations of coupling impedances were clarified. A summary session was held on the last day. Heavy emphasis was put on single bunched beam instabilities in the microwave region extending above the cut-off frequency of the ISABELLE vacuum chamber.

  3. 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.

  4. 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.

  5. 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

  6. 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...

  7. 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.

  8. 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...

  9. Summary statistics of neutral mutations in longitudinal DNA samples.

    Science.gov (United States)

    Liu, Xiaoming; Fu, Yun-Xin

    2008-08-01

    Longitudinal samples of DNA sequences are the DNA sequences sampled from the same population at different time points. For fast evolving organisms, e.g. RNA virus, these kind of samples have increasingly been used to study the evolutionary process in action. Longitudinal samples provide some interesting new summary statistics of genetic variation, such as the frequency of mutation of size i in one sample and size j in another, the average number of mutations accumulated since the common ancestor of two sequences each from a different sample, and number of private, shared and fixed mutations within samples. To make the results more applicable, we used in this study a general two-sample model, which assumes two longitudinal samples were taken from the same measurably evolving population. Inspired by the HIV study, we also studied a two-sample-two-stage model, which is a special case of two-sample model and assumes a treatment after the first sampling instantaneously changes the population size. We derived the formulas for calculating statistical properties, e.g. expectations, variances and covariances, of these new summary statistics under the two models. Potential applications of these results were discussed. PMID:18547598

  10. 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 and a...... 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....

  11. Modeling the Association Structure in Doubly Robust GEE for Longitudinal Ordinal Missing Data

    OpenAIRE

    da Silva, José Luiz P.; Enrico A. Colosimo; Demarqui, Fábio N.

    2015-01-01

    Generalized Estimation Equations (GEE) are a well-known method for the analysis of categorical longitudinal responses. GEE method has computational simplicity and population parameter interpretation. In the presence of missing data it is only valid under the strong assumption of missing completely at random. A doubly robust estimator (DRGEE) for correlated ordinal longitudinal data is a nice approach for handling intermittently missing response and covariate under the MAR mechanism. Independe...

  12. 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...

  13. Body Dissatisfaction from Adolescence to Young Adulthood: Findings from a 10-Year Longitudinal Study

    OpenAIRE

    Bucchianeri, Michaela M.; Arikian, Aimee J.; Hannan, Peter J.; Eisenberg, Marla E.; Neumark-Sztainer, Dianne

    2012-01-01

    Given mixed findings regarding the unique trajectories of female and male adolescents’ body dissatisfaction over time, comprehensive longitudinal examinations are needed. This 10-year longitudinal, population-based study, with 1,902 participants from diverse ethnic/racial and socioeconomic backgrounds in the Minneapolis/St. Paul metropolitan area, examined changes in body dissatisfaction from adolescence to young adulthood. Results revealed that: (a) female and male participants’ body dissati...

  14. A longitudinal study of food intake patterns and obesity in adult Danish men and women

    DEFF Research Database (Denmark)

    Togo, P; Osler, M; Sørensen, T I A;

    2004-01-01

    OBJECTIVE: The aim of this study was to test the hypothesis that specific food intake patterns or changes in food intake patterns were related to future changes in body mass index (BMI). DESIGN: Longitudinal observational study, with clinical and questionnaire examinations at baseline and two...... factor scores, changes in factor scores and subsequent BMI changes or obesity were found. CONCLUSION: In this longitudinal study of a Danish population, food intake factors could not consistently predict changes in BMI or obesity development....

  15. 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...

  16. 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...

  17. 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.

  18. 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 ...

  19. 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

  20. 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...

  1. 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...

  2. 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.

  3. MD on Injection Quality – Longitudinal and Transverse Parameters

    CERN Document Server

    Drosdal, L; Bohl, T; Bracco, C; Cornelis, K; Damerau, H; Goddard, B; Kain, V; Meddahi, M

    2011-01-01

    Losses at injection depend on the beam quality in the longitudinal and transverse plane in the injectors. During the MD on the 30th of June to 1st of July, 2011, many parameters in the injectors were de-tuned on purpose to see the effect on injection losses and hence bring some understanding to recurring problems with injection quality during LHC filling. The effect of the 800 MHz in the SPS, radial steering, larger momentum spread at the SPS extraction and many other longitudinal parameters were studied during the MD. The MD showed however that the injection losses are dominated by far by the transverse size of the particle population. If the SPS scrapers are correctly positioned, injection losses are low even at the presence of quality issues in the longitudinal plane. To be able to inject brighter 50 ns beams or eventually 25 ns beams, injection losses with nominal emittances (3.5 m) must still be acceptable. This MD showed that nominal emittances can be injected with similar loss levels as the typical ...

  4. 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…

  5. 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…

  6. Adiabatic Excitation of Longitudinal Bunch Shape Oscillations

    International Nuclear Information System (INIS)

    By modulating the rf voltage at near twice the synchrotrons frequency we are able to modulate the longitudinal bunch shape. We show experimentally that this can be done while preserving the longitudinal emittance when the rf voltage modulation is turned on adiabatically. Experimental measurements will be presented along with theoretical predictions

  7. 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.

  8. Longitudinal Phase Space Studies at PITZ

    CERN Document Server

    Roensch, J R

    2005-01-01

    The main goal of the Photo Injector Test facility at DESY Zeuthen (PITZ) is to test and to optimize photo injectors for Free-Electron Lasers (FELs). The demands on such a photo injector are small transverse emittances, short bunches and a high bunch charge. A FEL is driven by an accelerator which consists of a rf gun followed by an acceleration section and a magnetic bunch compressor. For the effective bunch compression detailed studies of the longitudinal phase space have to be performed. The correlation between the positions of the particles in the bunch and their longitudinal momenta has to be understood and the non-linearities of the longitudinal phase space have to be analysed. A special apparatus for longitudinal phase space tomography at 5 MeV using a dipole, a Cherenkov radiator, an optical transmission line and a streak camera was developed. Results of longitudinal phase space measurements are presented and compared with simulations.

  9. 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

  10. 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…

  11. 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…

  12. 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

  13. A Longitudinal Twin Study of the Direction of Effects between ADHD Symptoms and IQ

    OpenAIRE

    Rommel, Anna Sophie; Rijsdijk, Frühling; Greven, Corina U.; Asherson, Philip; Kuntsi, Jonna

    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 population-based sample of 4,771 twin pairs, DSM-IV ADHD symptoms were obtained from the Conners' Parent Rating Scale-Revised. Verbal (vocabulary) and performance (Raven's Progressive Matrices) IQ ...

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

    OpenAIRE

    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 population-based sample of 4,771 twin pairs, DSM-IV ADHD symptoms were obtained from the Conners' Parent Rating Scale-Revised. Verbal (vocabulary) and performance (Raven's Progressive Matrices) IQ ...

  15. 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...

  16. DROUGHT AND POPULATION MOBILITY IN RURAL ETHIOPIA

    OpenAIRE

    Gray, Clark; Mueller, Valerie

    2011-01-01

    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 ...

  17. 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.

  18. 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.

  19. 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.

  20. 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 ...

  1. 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...... environmental contribution to blood pressure but no genetic contribution to longitudinal change in body mass traits. CONCLUSION: Our results emphasize the major contribution of unique environment to the observed intra-individual variation in all metabolic phenotypes in both samples, and meanwhile reveal...... differential patterns of genetic and common environmental regulation on changes over time in metabolic phenotypes across the two samples....

  2. Energy dissipation by a longitudinal Raman process

    International Nuclear Information System (INIS)

    The concept of a longitudinal Raman process is introduced to encompass the indirect transmission of energy from slow electrons to nuclei through the reversible polarization of surrounding electrons. Experimental approaches are sought to assess this process quantitatively

  3. Modeling Disease Progression with Longitudinal Markers

    OpenAIRE

    Inoue, Lurdes Y.T.; Etzioni, Ruth; Morrell, Christopher; Müller, Peter

    2008-01-01

    In this paper we propose a Bayesian natural history model for disease progression based on the joint modeling of longitudinal biomarker levels, age at clinical detection of disease and disease status at diagnosis. We establish a link between the longitudinal responses and the natural history of the disease by using an underlying latent disease process which describes the onset of the disease and models the transition to an advanced stage of the disease as dependent on the biomarker levels. We...

  4. The muonic longitudinal shower profiles at production

    CERN Document Server

    Andringa, S; Conceição, R; Pimenta, M

    2011-01-01

    In this paper the longitudinal profile of muon production along the shower axis is studied. The characteristics of this distribution is investigated for different primary masses, zenith angles, primary energies, and different high energy hadronic models. It is found that the shape of this distribution displays universal features similarly to what is known for the electromagnetic profile. The relation between the muon production distribution and the longitudinal electromagnetic evolution is also discussed.

  5. 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...

  6. 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

  7. 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.

  8. 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…

  9. Development of a longitudinal density monitor for storage rings

    International Nuclear Information System (INIS)

    We report on development of a new storage ring operations tool for measurement of longitudinal beam density profile. The technique mixes synchrotron light with light from a mode locked solid-state laser oscillator in a non-linear crystal and detects the up-converted radiation with a photo-multiplier. The laser is phase locked to the storage ring RF system. The laser choices available for repetition frequency, pulse length and phase modulation give a very wide range of options for matching the bunch configuration of particular storage rings. Progress in the technology of solid-state lasers ensures this system can be made robust for routine use in storage ring operations. A very large number of important applications are possible including measurement of the fraction of untrapped particles prior to acceleration, the population of particles in the nominally unfilled RF buckets in a bunch train (''ghost bunches''), longitudinal tails, the diffusion of particles into the beam abort gap and th e normal bunch parameters of longitudinal shape and intensity. We are currently investigating application to two devices: (1) the 1.9 GeV ALS electron storage ring at LBNL with 328 RF buckets, 2ns bucket spacing, 276 nominally filled bunches, 15-30ps rms bunch length and (2) the 7 TeV LHC proton collider under construction at CERN with 35,640 RF buckets, 2.5 ns bucket spacing, 2,808 nominally filled bunches, 280-620 ps rms bunch length. A proof of principle experiment is being conducted on ALS. The results of the ALS experiment and detailed analyses of the application to LHC and its requirements are described

  10. Population crises and population cycles.

    Science.gov (United States)

    Russell, C; Russell, W M

    2000-01-01

    To prevent a population irretrievably depleting its resources, mammals have evolved a behavioural and physiological response to population crisis. When a mammalian population becomes dangerously dense, there is a reversal of behaviour. Co-operation and parental behaviour are replaced by competition, dominance and aggressive violence, leading to high mortality, especially of females and young, and a reduced population. The stress of overpopulation and the resulting violence impairs both the immune and the reproductive systems. Hence epidemics complete the crash of the population, and reproduction is slowed for three or four generations, giving the resources ample time to recover. In some mammal species, crisis and crisis response recur regularly, leading to cycles of population growth and relapse, oscillating about a fixed mean. Population crisis response and population cycles have been equally prominent in the history of human societies. But in man successive advances in food production have made possible growing populations, though with every such advance population soon outgrew resources again. Hence human cycles have been superimposed on a rising curve, producing a saw-tooth graph. Because advances in food production amounted to sudden disturbances in the relations between human populations and their environments, the crisis response in man has failed to avert famine and resource damage. In the large human societies evolved since the coming of settled agriculture and cities, the basic effects of violence, epidemics, famine and resource damage have been mediated by such specifically human disasters as inflation, unemployment, and political tyranny. An account of past crises, periods of relative relief from population pressure, and resulting cycles, is given for a number of regions: China, North Africa and Western Asia, the northern Mediterranean, and north-western Europe. The paper ends with an account of the present world-wide population crisis, and the solution

  11. 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

  12. 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.

  13. 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)

  14. 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.

  15. 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

  16. Bunched beam longitudinal instability: Coherent dipole motion

    International Nuclear Information System (INIS)

    In this paper, the authors present a new formulation for the longitudinal coherent dipole motion, where a quadrature response of the environmental impedance is shown to be the effective longitudinal impedance for the beam instability. The Robinson-Pedersen formulation for the longitudinal dipole motion is also presented, the difference of the two approaches is discussed in the comparison. The results by using the Sacherer integral equation for the coherent dipole motion can generate the same results as by using the other two approaches, except for a scaling difference. The formulation is further generalized to the rigid bunch motion using signal analysis method, where a form factor shows up naturally. Finally, the formulation is applied to solve the coupled bunch instabilities. Examples of the AGS Booster and the AGS coupled bunch instabilities are used to illustrate the applications of the formulation

  17. Longitudinal Electroproduction of Charged Pions from

    International Nuclear Information System (INIS)

    Separated longitudinal and transverse cross sections for charged pion electroproduction from 1H, 2H, and 3He were measured at Q2 = 0.4 (GeV/c)2 for two values of the invariant mass, (bar W) = 1.15 GeV and (bar W) = 1.60 GeV, in a search for a mass dependence which would signal the effect of nuclear pions. This is the first such study that includes recoil momenta significantly above the Fermi surface. The longitudinal cross section, if dominated by the pion-pole process, should be sensitive to nuclear pion currents. Comparisons of the longitudinal cross section target ratios to a quasifree calculation reveal a significant suppression in 3>He at (bar W) = 1.60 GeV. The (bar W) = 1.15 GeV results are consistent with simple estimates of the effect of nuclear pion currents, but are also consistent with pure quasifree production

  18. Emittance minimisation with longitudinal dipole field variation

    International Nuclear Information System (INIS)

    The reduction of horizontal emittance beyond the conventional limit is pursued by introducing a longitudinal variation of the field in a bending magnet. For a given dipole field, the search for the minimal emittance is formulated analytically under different boundary conditions, starting from the achromat condition, preferred for light source rings. With a dipole field rapidly decaying along the longitudinal position, it is shown that the emittance can be further reduced, essentially by rendering the H function to be out of phase with the third power of the local curvature. Under the minimal emittance condition analytically obtained, the optimal dipole field distribution is searched numerically with a polynomial function, analysing at the same time the mechanism of the emittance reduction. The minimal emittance is argued as a function of the required peak field and the field distribution. Adaptability of longitudinally varying dipole fields in a standard magnet lattice for light sources is also addressed

  19. Longitudinal diffusion of a proton bunch under external noise

    International Nuclear Information System (INIS)

    Evolution of longitudinal distribution of a proton bunch subjected to stationary (amplitude or phase) RF-noises is governed by a diffusion equation. Its diffusion coefficient is essentially nonlinear and, possibility, diverges near separatrix. The paper deals with the dynamical foundations of this diffusive approximation. Treated in detail is the motion of particles located either inside, or outside stationary buckets (beam halo). The formal statement of boundary-value problem for the noise-induced diffusion of a bunch (zero boundary conditions at separatrix, or at infinity) is discussed. Both these problems are solved numerically for arbitrarily long bunches. Use is made of the Finite Element Technique (spatial discretization), and of the Crank-Nicolson's scheme (time-domain integration). Computed estimates of the representative bunch life-times for the wide-band (white) noise approximation are presented. These emerge from the criteria of either bunch quality degradation, or of its population loss. 6 refs.; 11 figs

  20. 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.

  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. Longitudinal tibial epiphyseal bracket in Nievergelt syndrome

    International Nuclear Information System (INIS)

    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.)

  3. 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

  4. 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.

  5. 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

  6. Incidence of dental caries in primary dentition and risk factors: a longitudinal study

    OpenAIRE

    Patrícia CORRÊA-FARIA; Suzane PAIXÃO-GONÇALVES; Paiva, Saul Martins; Isabela Almeida PORDEUS

    2016-01-01

    Abstract The objectives of this prospective, longitudinal, population-based study were to estimate the incidence of dental caries in the primary dentition, identify risk factors and determine the proportion of children receiving dental treatment, through a two-year follow up. The first dental exam was conducted with 381 children aged one to five years, at health centers during immunization campaigns; 184 of them had dental caries and 197 had no caries experience. The second exam was carried o...

  7. Anxiety mediates the relationship between perfectionism and insomnia symptoms: A longitudinal study

    OpenAIRE

    Akram, Umair; Ellis, Jason; Barclay, Nicola

    2015-01-01

    Objectives Individuals with insomnia often report aspects of perfectionism and symptoms of anxiety and depression. Investigation of these factors together has been limited. As such, the aim of the present study was to examine the extent to which the association between perfectionism and insomnia symptoms was mediated by anxiety and depression, concurrently and longitudinally. Methods Seventy-six members from the general-population participated at baseline. Data from 57 participant...

  8. 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....

  9. 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.

  10. The longitudinal static stability of tailless aircraft

    OpenAIRE

    de Castro, Helena V.

    2001-01-01

    This paper describes the development of a simple theory of the longitudinal controls fixed static stability of tailless aeroplanes. The classical theory, as developed for the conventional aircraft, is modified to accommodate the particular features of the tailless aeroplanes. The theory was then applied to a particular blended-wing-body tailless civil transport aircraft, BWB-98.

  11. 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.

  12. 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.…

  13. 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…

  14. 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.

  15. 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 is cond...

  16. 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 (

  17. 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…

  18. 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…

  19. Are Body Dissatisfaction, Eating Disturbance, and Body Mass Index Predictors of Suicidal Behavior in Adolescents? A Longitudinal Study

    Science.gov (United States)

    Crow, Scott; Eisenberg, Marla E.; Story, Mary; Neumark-Sztainer, Dianne

    2008-01-01

    Disordered eating, body dissatisfaction, and obesity have been associated cross sectionally with suicidal behavior in adolescents. To determine the extent to which these variables predicted suicidal ideation and attempts, the authors examined these relationships in a longitudinal design. The study population included 2,516 older adolescents and…

  20. 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

  1. 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...

  2. TAILOR THE LONGITUDINAL ANAYSIS FOR NIH LONGITUDINAL NORMAL BRAIN DEVELOPMENTAL STUDY

    OpenAIRE

    Chen, Yasheng; An, Hongyu; Shen, Dinggang; Zhu, Hongtu; Lin, Weili

    2014-01-01

    There are imminent needs for longitudinal analysis to make physiological inferences on NIH MRI study of normal brain development. But up to date, two critical aspects for longitudinal analysis, namely the selections of mean and covariance structures have not been addressed by the neuroimaging community. For the mean structure, we employed a linear free-knot B-spline regression in combination with quasi-least square estimating equations to approximate a nonlinear growth trajectory with piecewi...

  3. 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

  4. Populations games

    Czech Academy of Sciences Publication Activity Database

    Křivan, Vlastimil

    2015-01-01

    Roč. 2, č. 1 (2015), s. 14-19. ISSN 2367-5233. [Featuring International Conferences Biomath 2015. Blagoevgrad, 14.06.2015-19.06.2015] R&D Projects: GA MŠk(CZ) EE2.3.30.0032 Institutional support: RVO:60077344 Keywords : populations dynamics

  5. Stellar Populations

    CERN Document Server

    Peletier, Reynier

    2012-01-01

    This is a summary of my lectures during the 2011 IAC 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 was {\\it Secular Evolution of 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 10. 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...

  6. 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

  7. Longitudinal Analyses of the Effects of Trade Unions

    OpenAIRE

    Freeman, Richard Barry

    1983-01-01

    This paper examines how measurement error biases longitudinal estimates of union effects. It develops numerical examples, statistical models, and econometric estimates which indicate that measurement error is a major problem in longitudinal data sets, so that longitudinal analyses do not provide the research panacea for determining the effects of unionism (or other economic forces) some have suggested. There are three major findings:1) The difference between the cross-section and longitudinal...

  8. 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.

  9. Ring RF and longitudinal dynamics in the SNS

    International Nuclear Information System (INIS)

    Average beam currents of 40 A will be present in the Spallation Neutron Source. Even though the entire cycle time is only one synchrotron oscillation the longitudinal phase space determines peak beam current and momentum spread. Both factors play a role in space charge and instability dynamics. Longitudinal simulations with beam loading and longitudinal space charge have been done in the design phase

  10. 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...

  11. 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...

  12. Reconsidering the Effects of Poverty and Social Support on Health: A 5-Year Longitudinal Test of the Stress-Buffering Hypothesis

    OpenAIRE

    Moskowitz, David; Vittinghoff, Eric; Schmidt, Laura

    2012-01-01

    Prior research in the general population has found that social support can buffer the adverse effects of stressors on health. However, both stressors and social support may be qualitatively different for those living in urban poverty. We examined the effects of social support and poverty-specific stressors on self-rated health. We used data from the Welfare Client Longitudinal Survey (WCLS), a 5-year longitudinal study of 718 public aid recipients. We measured received social support and “net...

  13. Tourette syndrome and chronic tic disorder are associated with lower socio-economic status: Findings from the Avon Longitudinal Study of Parents and Children cohort

    OpenAIRE

    Miller, LL; Scharf, JM; Mathews, CA; Ben-Shlomo, Y.

    2013-01-01

    Aim: Only a few studies have examined the relationship between Tourette syndrome or chronic tic disorder and socio-economic status (SES). Existing studies are primarily cross-sectional, arise from specialty clinics, and use single measures of SES. In this study we examine this relationship in a longitudinal, population-based sample. Method: Data are from 7152 children born during 1991 and 1992 in the county of Avon, UK, from the Avon Longitudinal Study of Parents and Children, who were follow...

  14. Tourette syndrome and chronic tic disorder are associated with lower socio-economic status: findings from the Avon Longitudinal Study of Parents and Children cohort

    OpenAIRE

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

    2013-01-01

    Aim Only a few studies have examined the relationship between Tourette syndrome or chronic tic disorder and socio-economic status (SES). Existing studies are primarily cross-sectional, arise from specialty clinics, and use single measures of SES. In this study we examine this relationship in a longitudinal, population-based sample. Method Data are from 7152 children born during 1991 and 1992 in the county of Avon, UK, from the Avon Longitudinal Study of Parents and Children, who were followed...

  15. 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...

  16. 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

  17. 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...

  18. 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

  19. Batch By Batch Longitudinal Emittance Blowup MD

    CERN Document Server

    Mastoridis, T; Butterworth, A; Jaussi, M; Molendijk, J

    2012-01-01

    The transverse bunch emittance increases significantly at 450 GeV from the time of injection till the ramp due to IBS. By selectively blowing up the longitudinal emittance of the incoming batch at each injection, it should be possible to reduce the transverse emittance growth rates due to IBS. An MD was conducted on April 22nd 2012 to test the feasibility and performance of the batch-by-batch longitudinal emittance blowup. There were three main goals during the MD. First, to test the developed hardware, firmware, and software for the batch-by-batch blowup. Then, to measure the transverse emittance growth rates of blown-up and "witness" batches to quantify any improvement, and finally to test the ALLInjectSequencer class, which deals with the complicated gymnastics of introducing or masking the new batch to various RF loops.

  20. RADON reconstruction in longitudinal phase space

    International Nuclear Information System (INIS)

    Longitudinal particle motion in circular accelerators is typically monitoring by one dimensional (1-D) profiles. Adiabatic particle motion in two dimensional (2-D) phase space can be reconstructed with tomographic techniques, using 1-D profiles. A computer program RADON has been developed in C++ to process digitized mountain range data and perform the phase space reconstruction for the AGS, and later for Relativistic Heavy Ion Collider (RHIC)

  1. Fmcw Mmw Radar For Automotive Longitudinal Control

    OpenAIRE

    David, William

    1997-01-01

    This report presents information on millimeter wave (MMW) radar for automotive longitudinal control. It addresses the fundamental capabilities and limitations of millimeter waves for ranging and contrasts their operation with that of conventional microwave radar. The report analyzes pulsed and FMCW radar configurations, and provides detailed treatment of FMCW radar operating at MMW frequency, its advantages and disadvantages as they relate to range and velocity measurements.

  2. GEE for GWAS using Longitudinal Phenotype Data

    OpenAIRE

    Sitlani, Colleen M.; Rice, Kenneth M.; Lumley, Thomas; McKnight, Barbara; Cupples, L. Adrienne; Avery, Christy L; Noordam, Raymond; Stricker, Bruno H. C.; Whitsel, Eric A.; Psaty, Bruce M.

    2014-01-01

    Many longitudinal cohort studies have both genome-wide measures of genetic variation and repeated measures of phenotypes and environmental exposures. Genome-wide association study analyses have typically used only cross-sectional data to evaluate quantitative phenotypes and binary traits. Incorporation of repeated measures may increase power to detect associations, but also requires specialized analysis methods. Here we discuss one such method – generalized estimating equations...

  3. 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.

  4. Congenital longitudinal deficiency of the tibia

    OpenAIRE

    Spiegel, D. A.; Loder, R T; Crandall, R. C.

    2003-01-01

    We performed a clinical and radiographic review of 15 patients (19 limbs) with longitudinal deficiency of the tibia treated between 1981 and 2001. Ten limbs with Kalamchi type I deficiencies were managed by through-knee amputation. Five type II deficiencies were treated by foot ablation and tibiofibular synostosis, either at the same time or staged, but prosthetic problems may arise from varus alignment and prominence of the proximal fibula. Patients with type III deficiencies (four cases) we...

  5. 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...

  6. Longitudinal damping system for the Fermilab Booster

    International Nuclear Information System (INIS)

    The general idea behind the damping system is to take from the beam-spectrum the instability frequency components (synchrotron sidebands), and to feed them back with the proper phase to create negative feedback. The paper describes the different building blocks of a new longitudinal damping system in the Fermilab Booster and the main design considerations. The system design has been completed. The prototype is currently being built and tested. First system integration with the Booster is expected in August 1991

  7. Temporal dependence in longitudinal paired comparisons

    OpenAIRE

    Dittrich, Regina; Francis, Brian; Katzenbeisser, Walter

    2008-01-01

    This paper develops a new approach to the analysis of longitudinal paired comparison data, where comparisons of the same objects by the same judges are made on more than one occasion. As an alternative to other recent approaches to such data, which are based on Kalman filter- ing, our approach treats the problem as one of multivariate multinomial data, allowing dependence terms between comparisons over time to be incorporated. The resulting model can be fitted as a Poisson log-linear model an...

  8. 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...

  9. Longitudinal studies of trauma in police officers

    OpenAIRE

    Charles Marmar

    2012-01-01

    Background : Results will be presented on a prospective longitudinal study of risk and resilience for post-traumatic stress disorder (PTSD) symptoms in 400 police academy recruits, assessed during academy training and followed during the first 7 years of police service. Methods : Utilizing Latent Growth Mixture Modeling (LGMM) we have established three symptom trajectories, highly resilient, initially distressed with gradual improvement, and increasing distress. Results : We will present find...

  10. 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.

  11. Modeling HIF relevant longitudinal dynamics in UMER

    International Nuclear Information System (INIS)

    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

  12. 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%

  13. Longitudinal Electroproduction of Charged Pions from

    Energy Technology Data Exchange (ETDEWEB)

    David Gaskell; Abdellah Ahmidouch; Pawel Ambrozewicz; H. Anklin; John Arrington; K. Assamagan; Steven Avery; Kevin Bailey; Oliver K. Baker; Shelton Beedoe; Elizabeth Beise; Herbert Breuer; D. S. Brown; Roger Carlini; Jinseok Cha; Nicholas Chant; Anthony Cowley; Samuel Danagoulian; D. De Schepper; Jim Dunne; Dipangkar Dutta; Rolf Ent; Liping Gan; Ashot Gasparian; Donald Geesaman; Ron Gilman; Charles Glashausser; Paul Gueye; M. Harvey; O. Hashimoto; Wendy Hinton; G. Hofman; Ceasar Jackson; Hal Jackson; Cynthia Keppel; Ed Kinney; Doug Koltenuk; G. Kyle; Allison Lung; David Mack; D. McKee; Joseph Mitchell; Hamlet Mkrtchyan; B. Mueller; Gabriel Niculescu; Ioana Niculescu; Tom O' Neill; V. Papavassiliou; Dave Potterveld; Juerg Reinhold; Philip Roos; Reyad Sawafta; Ralph Segel; Stepan Stepanyan; Vardan Tadevosyan; T. Takahashi; Liguang Tang; B. Terburg; D. Van Westrum; J. Volmer; T. P. Welch; Stephen Wood; Lulin Yuan; Ben Zeidman; Beni Zihlmann

    2001-11-12

    Separated longitudinal and transverse cross sections for charged pion electroproduction from {sup 1}H, {sup 2}H, and {sup 3}He were measured at Q{sup 2} = 0.4 (GeV/c){sup 2} for two values of the invariant mass, {bar W} = 1.15 GeV and {bar W} = 1.60 GeV, in a search for a mass dependence which would signal the effect of nuclear pions. This is the first such study that includes recoil momenta significantly above the Fermi surface. The longitudinal cross section, if dominated by the pion-pole process, should be sensitive to nuclear pion currents. Comparisons of the longitudinal cross section target ratios to a quasifree calculation reveal a significant suppression in {sup 3>}He at {bar W} = 1.60 GeV. The {bar W} = 1.15 GeV results are consistent with simple estimates of the effect of nuclear pion currents, but are also consistent with pure quasifree production.

  14. 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.

  15. Population geography.

    Science.gov (United States)

    Nash, A

    1994-03-01

    Population geographers are involved in contemporary policy issues, the production of quality work, and successful communication of research findings. This article reviewed some contributions population geographers have made to the understanding of the geographic impact of aging and the consequences of migration. Geographers have come late to the study of aging and have focused primarily on four main policy issues: 1) fertility decline, 2) housing demography, 3) aged patterns of housing and migration, and 4) government policy. Fertility decline research has highlighted information diffusion theories for fertility decline by researchers such as Zelinsky, Skeldon, and Noin. Changes in attitudes and the removal on constraints has been examined by Woods. Residential mobility studies have been the focus of researchers such as Gober, Moore, and Clark, and Myers. Regional labor markets and the movement of the "baby boom" through the life course have been examined by Miron, Plane and Rogerson, and Clout, who studied the empty nesters and the movement out of suburbia. Private residential housing has increased for the elderly in England and Wales (Hamnett and Mullings), and seasonal migration of Minnesotans results in lost sales revenues and high health and social costs for those too ill to travel (Craig). Geographers have not accomplished a significant thrust into the literature on demographic aging. Contributions to the transnational and international literature have resulted in internal migration studies by Clout on "counterurbanization" in northwestern industrial Europe, while Fielding, Baltensperger, Marchand and Scott, and Jones have examined the continuing rural-urban migration. The loss of urban population has been associated with inner city problems, the impact of labor supply and market demand, and the revenue and health care consequences in the work of Champion, Gibson, and Champion and Illeris, and Craig. Impacts are felt differently by geographic location, and

  16. Behavioural divergence of sympatric Anopheles funestus populations in Burkina Faso

    OpenAIRE

    Guelbeogo, Wamdaogo M.; Sagnon, N’Fale; Liu, Fang(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China); Nora J Besansky; Costantini, Carlo

    2014-01-01

    Background In Burkina Faso, two chromosomal forms of the malaria vector Anopheles funestus, Folonzo and Kiribina, are distinguished by contrasting frequencies of shared polymorphic chromosomal inversions. Sympatric and synchronous populations of Folonzo and Kiribina mate assortatively, as indicated by a significant deficit of heterokaryotypes, and genetic associations among inversions on independently segregating chromosome arms. The present study aimed to assess, by intensive longitudinal sa...

  17. The Black-White Environmental Concern Gap: An Examination of Environmental Paradigms.

    Science.gov (United States)

    Sheppard, Judi

    1995-01-01

    Differences in environmental world views of 72 whites and 40 African Americans were investigated by contrasting dimensions of two opposing paradigms: the dominant social paradigm that emphasizes exploiting nature and the new environmental paradigm that emphasizes harmony and stewardship. Results reveal that differences between the races are small.…

  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. Black-white differences in intergenerational economic mobility in the US

    OpenAIRE

    Mazumder, Bhashkar

    2011-01-01

    Traditional measures of intergenerational mobility such as the intergenerational elasticity are not useful for inferences concerning group differences in mobility with respect to the pooled income distribution. This paper uses transition probabilities and measures of “directional rank mobility” that can identify interracial differences in intergenerational mobility. The study uses two data sources, including one that contains social security earnings for a large intergenerational sample. I fi...

  20. 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...

  1. 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)

  2. Alcohol Use and Delinquency among Black, White and Hispanic Adolescent Offenders.

    Science.gov (United States)

    Dawkins, Russell L.; Dawkins, Marvin P.

    1983-01-01

    Examined the relationship between drinking and criminal behavior among 342 adolescent offenders. Results showed drinking is strongly associated with minor offenses. Relative to background and behavioral factors, drinking is the strongest single predictor of serious criminal offenses among Blacks, with less importance for whites and little…

  3. X-ray investigation of phosphors for black-white television

    International Nuclear Information System (INIS)

    The investigations of phosphors made by means of the powder diffraction method are presented. The diffraction patterns has been obtained by means of the DRON-1 diffractometer, using the Ksub(α) copper radiation and a nickel filter. Reflex intensity was estimated, indexing was made and lattice constants for particular structure types were calculated. The objects of the investigations were the phosphors from various firms of white luminescence and home phosphors of white, blue and yellow luminescence. On the base of the results it was found that all investigated phosphors of yellow luminescence belonged to the hexagonal system. These phosphors, depending on baking conditions, have structure of regular symmetry. The phosphors of white luminescence are a mixture of hexagonal and regular phase and any changes in elementary cell sizes were not observed. All phosphors of white luminescence have analogous structure, positions of all reflexes are identical, negligible differences in their intensities occur only, which proves somewhat different arrangement of atoms in mixed crystals. (author)

  4. Black-white differences in alcohol use by women: Baltimore survey findings.

    OpenAIRE

    Lillie-Blanton, M; MacKenzie, E; Anthony, J. C.

    1991-01-01

    Although black women suffer disproportionately from alcohol-related illnesses and causes of death, little is known about the extent to which poorer outcomes are a function of differences in drinking, the use of health services, or some combination of these factors. This study, using interview data obtained in the Baltimore Epidemiologic Catchment Area household survey, compares racial differences in alcohol use and abuse among a sample of 2,100 women. After controlling for differences in soci...

  5. 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

  6. Black-White Disparities in Colorectal Cancer Incidence, Screening, and Outcomes

    OpenAIRE

    May, Folasade P.

    2015-01-01

    African Americans are disproportionately impacted by colorectal cancer (CRC) with higher incidence of disease, higher mortality from disease, and poorer disease survival. These disparities are likely the result of multiple factors, including a high prevalence of CRC risk factors, unfavorable tumor biology, and poor access to medical services among blacks. In addition, while national guidelines promote universal screening for CRC in all Americans, African Americans are less likely than white A...

  7. The Role of Permanent Income and Demographics in Black/White Differences in Wealth

    OpenAIRE

    Altonji, Joseph G.; Doraszelski, Ulrich

    2000-01-01

    We explore the extent to which the huge race gap in wealth can be explained with properly constructed income and demographic variables. In some instances we explain the entire wealth gap with income and demographics provided that we estimate the wealth model on a sample of whites. However, we typically explain a much smaller fraction when we estimate the wealth model on a black sample. Using sibling comparisons to control for intergenerational transfers and the effects of adverse history, we ...

  8. 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

  9. 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…

  10. 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,…

  11. Seasonal Changes in Lung Function in a Farming Population

    OpenAIRE

    Ambikaipakan Senthilselvan; Dosman, James A; Semchuk, Karen M; Helen H McDuffie; Cessna, Allan J; Donald G Irviine; Margaret FO Crossley; Alan Rosenberg

    2000-01-01

    OBJECTIVE: To assess the changes in respiratory health from winter to summer seasons in a rural population.DESIGN: A longitudinal design was used in the study.SETTING: A population-based study was conducted as part of the Environmental Pesticide Exposure and Human Health component of the Prairie Ecosystem Study (PECOS) in southwestern Saskatchewan.PATIENTS: In the winter season, 358 patients participated in the study. Of these patients, 234 returned for the second assessment during the summer...

  12. 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

  13. 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

  14. 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

  15. 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.

  16. Design of the PS longitudinal damper

    CERN Document Server

    Paoluzzi, M

    2013-01-01

    The longitudinal damper cavity for the new coupled-bunch feedback of the PS machine has to provide a correcting RF voltage to the circulating bunches to suppress the excitation of bunch oscillations. In the framework of the LHC Injector Upgrade (LIU) project, it has been decided to install a dedicated wideband kicker cavity (0.5-5.5MHz) driven by solid-state amplifiers and providing up to 5 kV peak RF voltage. This paper describes the beam characteristics, the high power system requirements, its design and the foreseen protections.

  17. 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.

  18. Congenital longitudinal deficiency of the tibia.

    Science.gov (United States)

    Spiegel, D A; Loder, R T; Crandall, R C

    2003-01-01

    We performed a clinical and radiographic review of 15 patients (19 limbs) with longitudinal deficiency of the tibia treated between 1981 and 2001. Ten limbs with Kalamchi type I deficiencies were managed by through-knee amputation. Five type II deficiencies were treated by foot ablation and tibiofibular synostosis, either at the same time or staged, but prosthetic problems may arise from varus alignment and prominence of the proximal fibula. Patients with type III deficiencies (four cases) were treated by foot ablation. Prosthetic problems relating to proximal or distal tibiofibular instability may necessitate additional surgical intervention. PMID:12879290

  19. 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.

  20. 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...

  1. Longitudinal photo-documentation: recording living walls

    OpenAIRE

    Hansen, Susan; Flynn, Danny A.

    2015-01-01

    This working paper advocates a methodological approach to the study of street art and graffiti that is based on the documentation of single sites over time. Longitudinal photo-documentation is a form of data collection that allows street art and graffiti to be examined as visual dialogue. By capturing everyday forms of public mark making alongside both more recognizably ‘artistic’ images, and more visually ‘offensive’ tags, we aim to attend to graffiti and street art’s existence within a fiel...

  2. 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...

  3. 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...

  4. 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. ...

  5. 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...

  6. Impedance studies for the PS Finemet loaded longitudinal damper

    CERN Document Server

    Persichelli, S; Paoluzzi, M; Salvant, B

    2014-01-01

    The impedance of the Finemet® loaded longitudinal damper cavity, installed in the CERN Proton Synchrotron straight section 02 during the Long Shutdown 2013-2014, has been evaluated [1]. Time domain simulations with CST Particle Studio have been performed in order to get the longitudinal and transverse impedance of the device and make a comparison with the longitudinal impedance that was measured for a single cell prototype.

  7. 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...

  8. 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.

  9. 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.)

  10. 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.

  11. 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

  12. 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...

  13. Colorado longitudinal twin study of reading disability.

    Science.gov (United States)

    Wadsworth, Sally J; DeFries, John C; Olson, Richard K; Willcutt, Erik G

    2007-12-01

    The primary objectives of the present study are to introduce the Colorado Longitudinal Twin Study of Reading Disability, the first longitudinal twin study in which subjects have been specifically selected for having a history of reading difficulties, and to present some initial assessments of the stability of reading performance and cognitive abilities in this sample. Preliminary examination of the test scores of 124 twins with a history of reading difficulties and 154 twins with no history of reading difficulties indicates that over the 5- to 6-year interval between assessments, cognitive and reading performance are highly stable. As a group, those subjects with a history of reading difficulties had substantial deficits relative to control subjects on all measures at initial assessment, and significant deficits remained at follow-up. The stability noted for all cognitive and achievement measures was highest for a composite measure of reading, whose average stability correlation across groups was 0.80. Results of preliminary behavior genetic analyses for this measure indicated that shared genetic influences accounted for 86% and 49% of the phenotypic correlations between the two assessments for twin pairs with and without reading difficulties, respectively. In addition, genetic correlations reached unity for both groups, suggesting that the same genetic influences are manifested at both time points. PMID:18060583

  14. 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

  15. 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.

  16. 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

  17. 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

  18. Design for a Longitudinal Density Monitor for the LHC

    International Nuclear Information System (INIS)

    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.

  19. 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...

  20. Normal fetal growth evaluated by longitudinal ultrasound examinations.

    Science.gov (United States)

    Larsen, T; Petersen, S; Greisen, G; Larsen, J F

    1990-10-01

    Fetal weight estimation was evaluated using the equations of Warsof, Shepard and Hadlock in 192 patients, less than 3 days before delivery. Warsof's and Hadlock's equations resulted in significantly better weight estimates compared to Shepard's equation. No systematic error was found below 2500 g by use of Warsof's equation, whereas Shepard's and Hadlocks's equations resulted in significant over-estimation in the low weight group. In a study of 5 fetuses, of 27-38 weeks gestational age, the intra-observer variation was calculated to 4.6%, whereas the coefficient of variation among observer means was 2.9%. The mixed intra- and inter-observer coefficient of variation was 6.5%. Thirty-five low-risk, uncomplicated pregnancies with reliable last menstrual dates were investigated longitudinally with ultrasound measurements of fetal weight. Population growth curves of fetal weight, fetal femur length, abdominal circumference and biparietal diameter were constructed by weighted polynomial regression. After 27 weeks of gestational age the weight growth curve showed only insignificant non-linearity. Compared to a Danish growth curve based on birth weights, significant higher mean weight was found, especially before 31 weeks of gestational age. The 10th and 90th percentiles for the individual percentage deviation change was +/- 4.4% per 28 days. PMID:2265597

  1. 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.

  2. 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

  3. 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.

  4. 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...

  5. Longitudinal beam dynamics for heavy ion fusion

    International Nuclear Information System (INIS)

    The longitudinal wall impedance instability is of great interest for a heavy ion fusion (HIF) driver because complete stabilization of this mode via momentum spread is impractical due to requirements of focusing the beam onto the inertial confinement fusion target. This instability is being studied with the WARPrz particle-in-cell code. The impedance of the induction linac modules is modeled as a wall impedance corresponding to a continuum of resistors and capacitors in parallel. We discuss simulations of the this instability, including reflections of perturbations off the beam end and the effects of finite temperature, and simulations of errors in intermittently-applied axial confining fields as a seed for this instability. We also present very long simulations in which we look for beam equilibria

  6. Longitudinal response of confined semiflexible polymers

    Science.gov (United States)

    Thüroff, Florian; Obermayer, Benedikt; Frey, Erwin

    2011-02-01

    The longitudinal response of single semiflexible polymers to sudden changes in externally applied forces is known to be controlled by the propagation and relaxation of backbone tension. Under many experimental circumstances, realized, for example, in nanofluidic devices or in polymeric networks or solutions, these polymers are effectively confined in a channel- or tubelike geometry. By means of heuristic scaling laws and rigorous analytical theory, we analyze the tension dynamics of confined semiflexible polymers for various generic experimental setups. It turns out that in contrast to the well-known linear response, the influence of confinement on the nonlinear dynamics can largely be described as that of an effective prestress. We also study the free relaxation of an initially confined chain, finding a surprising superlinear ~t9/8 growth law for the change in end-to-end distance at short times.

  7. Longitudinal reproductive hormone profiles in infants

    DEFF Research Database (Denmark)

    Andersson, A M; Toppari, J; Haavisto, A M; Petersen, J H; Simell, T; Simell, O; Skakkebaek, N E

    1998-01-01

    influence male reproductive health in adulthood. The early postnatal activity of the Sertoli cell, a testicular cell type that is supposed to play a major role in sperm production in adulthood is largely unknown. Recently, the peptide hormone inhibin B was shown to be a marker of Sertoli cell function in...... the adult male. In the adult woman, inhibin B is secreted by the granulosa cells. Longitudinal serum levels of inhibin B were measured in healthy boys (n = 15) and girls (n = 15), in cord blood, and every third month during the first 2 yr of life. In addition, serum levels of FSH, LH, and testosterone...... high interindividual variation in levels of inhibin B, FSH, and LH within each age. In conclusion, the sustained elevation of inhibin B to supraadult levels in infant boys indicates that the neonatal period may be a developmental window important for Sertoli cell proliferation and maturation. Thus, the...

  8. 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

  9. 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

  10. 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.

  11. 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.

  12. 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.)

  13. 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.

  14. 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…

  15. 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.

  16. 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.

  17. 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...

  18. 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…

  19. 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…

  20. 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.

  1. Longitudinal Research with Sexual Assault Survivors: A Methodological Review

    Science.gov (United States)

    Campbell, Rebecca; Sprague, Heather Brown; Cottrill, Sara; Sullivan, Cris M.

    2011-01-01

    Longitudinal research designs are relatively rare in the academic literature on rape and sexual assault despite their tremendous methodological rigor and scientific utility. In the interest of promoting wider use of such methods, we conducted a methodological review of projects that have used prospective longitudinal designs to study the…

  2. Longitudinal particle simulation for J-PARC RCS

    International Nuclear Information System (INIS)

    The beam commissioning has been going at the J-PARC RCS. Some longitudinal beam gymnastics and the acceleration has been successfully performed under the high intensity operation. We had developed the longitudinal particle tracking code with the beam loading and the space charge effects. The comparison between the beam test result and the particle tracking simulation is described. (author)

  3. A Longitudinal Investigation of Role Taking, Altruism, and Empathy.

    Science.gov (United States)

    Iannotti, Ronald J.

    This paper describes a one-year longitudinal follow up study of the long term effects of role taking training procedures (in which children assumed a number of perspectives) on children's social and cognitive behaviors. Longitudinal and cross-sectional age effects were also analyzed. In an earlier study the effect of two types of role-taking…

  4. 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 for this...

  5. Longitudinal investigation of methamphetamine use among gay and bisexual men in New York City: Findings from project BUMPS

    OpenAIRE

    Halkitis, Perry N.; Green, Kelly A.; Mourgues, Paris

    2005-01-01

    In recent years, methamphetamine has become a drug more commonly used among gay and bisexual men in New York City. Part of a longitudinal investigation of drug abuse in this population involved assessing the patterns and context of methamphetamine use during the course of 1 year. Findings indicate that among self-identified club-drug-using men, methamphetamine is widely used by men across age groups, educational level, racelethnicity, and HIV status. Participants reported use of methamphetami...

  6. 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...

  7. 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...

  8. Large-scale alcohol use and socioeconomic position of origin: longitudinal study from ages 15 to 19 years

    DEFF Research Database (Denmark)

    Andersen, Anette; Holstein, Bjørn E; Due, Pernille

    2008-01-01

    AIM: To examine socioeconomic position (SEP) of origin as predictor of large-scale alcohol use in adolescence. METHODS: The study population was a random sample of 15-year-olds at baseline (n=843) with a first follow-up 4 years later (n=729). Excess alcohol intake was assessed by consumption last...... longitudinal study found a weak association between low family SEP at age 15 years and excess alcohol drinking at age 19 years, but the association was not significant....

  9. Feeding Intolerance and Poor Growth in Infants with Gastroschisis: Longitudinal Experience with Consecutive Patients over Thirteen Years

    OpenAIRE

    Saloni Balgi; Sarita Singhal; Georgia Mueller; Beau Batton

    2015-01-01

    Objectives: 1) To investigate in-hospital factors associated with delayed tolerance of full volume enteral nutrition and 2) To assess longitudinal growth in a contemporary population of infants with gastroschisis.Design: Retrospective single-center study of all infants with gastroschisisSetting: Level III neonatal intensive care unit in a free-standing Children’s HospitalDuration: 13.5 yearsMaterials & Methods: Detailed data regarding demographics, nutritional support, growth, and infant ...

  10. 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). ...

  11. 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 ...

  12. 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 ...

  13. 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...

  14. 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...

  15. Impact of stress coping capacity on recovery from abdominal hysterectomy in a fast-track programme: a prospective longitudinal study

    OpenAIRE

    Kjölhede, Preben; Borendal Wodlin, Ninnie; Nilsson, Lena; Fredrikson, Mats; Wijma, Klaas

    2012-01-01

    Objective To evaluate the effect of stress coping capacity in combination with mode of anaesthesia on postoperative recovery in fast-track abdominal hysterectomy. Design Prospective longitudinal study. Setting Five hospitals in the south-east of Sweden. Population A cohort of 162 women undergoing fast-track abdominal hysterectomy for benign conditions. Methods Self-administered questionnaires, the Stress Coping Inventory (SCI) and the Swedish Postoperative Symptom Questionnaire (SPSQ), and cl...

  16. 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

  17. The Longitudinal Youth at Risk Study (LYRIKS)--an Asian UHR perspective.

    Science.gov (United States)

    Lee, Jimmy; Rekhi, Gurpreet; Mitter, Natasha; Bong, Yioe Ling; Kraus, Michael S; Lam, Max; Rapisarda, Attilio; Lee, Tih-Shih; Subramaniam, Mythily; Chong, Siow Ann; Keefe, Richard S E

    2013-12-01

    Numerous studies have been published on the psychosis prodrome and have explored a wide array of its many aspects. However, the set of risk factors identified by these various efforts is not homogenous across studies. This could be due to unique population factors or relatively small sample sizes. Only few studies were conducted on Asian populations, whose socio-cultural characteristics differ - in some cases remarkably - from those in western populations. Singapore is a highly dense city-state in South-east Asia, with low rates of substance abuse. The Longitudinal Youth at Risk Study (LYRIKS) commenced in Singapore in 2008, designed to comprehensively assess a group of ultra high risk (UHR) individuals and identify clinical, social, neuropsychological and biological risk factors unique to the local population. 173 UHR individuals were recruited from this single-site study over 4 years. Here, we detail aspects of the study methodology and report on the baseline social and clinical characteristics of the sample population. 78% of the UHR sample suffered from a psychiatric disorder, with Major Depressive Disorder present in more than half of the sample. The mean Global Assessment of Functioning (GAF) score was 57.4, which indicated a moderate level of impairment. Although the recruited sample did not differ significantly by social and clinical characteristics when compared to previously published reports, the conversion rate to psychosis was 3.5% (n=6) at 6 months. Follow-up measures are currently underway to assess longitudinal incidence of psychosis and impact of risk factors on cognition, functioning and remission. PMID:24139196

  18. 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

  19. 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

  20. 78 FR 44553 - Agency Information Collection Activities; Comment Request; Early Childhood Longitudinal Study...

    Science.gov (United States)

    2013-07-24

    ... Agency Information Collection Activities; Comment Request; Early Childhood Longitudinal Study... notice will be considered public records. Title of Collection: Early Childhood Longitudinal Study... sister study, the Early Childhood Longitudinal Study, Kindergarten Class of 1998-99 (ECLS-K), the...

  1. 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...

  2. Perceived weight discrimination in England: a population-based study of adults aged >50 years.

    OpenAIRE

    Jackson, S.E.; STEPTOE, A; Beeken, R. J.; Croker, H.; Wardle, J.

    2014-01-01

    Background:Despite a wealth of experimental studies on weight bias, little is known about weight discrimination at the population level. This study examined the prevalence and socio-demographic correlates of perceived weight discrimination in a large population-based sample of older adults.Methods:Data were from 5307 adults in the English Longitudinal Study of Ageing; a population-based cohort of men and women aged ⩾50 years. Weight discrimination was reported for five domains (less respect/c...

  3. 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

  4. Gastroesophageal reflux symptoms in infants in a rural population: longitudinal data over the first six months

    Directory of Open Access Journals (Sweden)

    Storms Michelle R

    2010-02-01

    Full Text Available Abstract Background Increasing numbers of infants are receiving prescription medications for symptoms associated with gastroesophageal reflux. Our aim was to prospectively measure reported gastroesophageal reflux symptoms in healthy term infants for the first six months of life. Methods In a prospective cohort study in the rural Upper Peninsula of Michigan, 128 consecutive maternal-infant pairs were followed for six months and administered the Infant Gastroesophageal Reflux Questionnaire Revised (I-GERQ-R at the one-month, two-month, four-month, and six-month well-child visits. Results The I-GERQ-R scores decreased with age. Average scores were 11.74 (SE = 5.97 at one-month, 9.97(4.92 at two-months, 8.44(4.39 at four-months, and 6.97(4.05 at six months. Symptoms associated with colic were greatest at one month of age. Conclusion Symptoms of gastroesophageal reflux as measured by the I-GERQ-R decrease with age in the first six months of life in otherwise healthy infants; however the I-GERQ-R may have difficulty differentiating gastroesophageal reflux disease from colic in those under 3 months of age.

  5. Gastroesophageal reflux symptoms in infants in a rural population: longitudinal data over the first six months

    OpenAIRE

    Storms Michelle R; Van Howe Robert S

    2010-01-01

    Abstract Background Increasing numbers of infants are receiving prescription medications for symptoms associated with gastroesophageal reflux. Our aim was to prospectively measure reported gastroesophageal reflux symptoms in healthy term infants for the first six months of life. Methods In a prospective cohort study in the rural Upper Peninsula of Michigan, 128 consecutive maternal-infant pairs were followed for six months and administered the Infant Gastroesophageal Reflux Questionnaire Revi...

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

    OpenAIRE

    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 identify...

  7. 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.

  8. 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…

  9. 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.

  10. Predicting Early School Achievement with the EDI: A Longitudinal Population-Based Study

    Science.gov (United States)

    Forget-Dubois, Nadine; Lemelin, Jean-Pascal; Boivin, Michel; Dionne, Ginette; Seguin, Jean R.; Vitaro, Frank; Tremblay, Richard E.

    2007-01-01

    School readiness tests are significant predictors of early school achievement. Measuring school readiness on a large scale would be necessary for the implementation of intervention programs at the community level. However, assessment of school readiness is costly and time consuming. This study assesses the predictive value of a school readiness…

  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. GEE for GWAS using Longitudinal Phenotype Data

    Science.gov (United States)

    Sitlani, Colleen M.; Rice, Kenneth M.; Lumley, Thomas; McKnight, Barbara; Cupples, L. Adrienne; Avery, Christy L.; Noordam, Raymond; Stricker, Bruno H.C.; Whitsel, Eric A.; Psaty, Bruce M.

    2014-01-01

    Many longitudinal cohort studies have both genome-wide measures of genetic variation and repeated measures of phenotypes and environmental exposures. Genome-wide association study analyses have typically used only cross-sectional data to evaluate quantitative phenotypes and binary traits. Incorporation of repeated measures may increase power to detect associations, but also requires specialized analysis methods. Here we discuss one such method – generalized estimating equations (GEE) – in the contexts of analysis of main effects of rare genetic variants and analysis of gene-environment interactions. We illustrate the potential for increased power using GEE analyses instead of cross-sectional analyses. We also address challenges that arise, such as the need for small-sample corrections when the minor allele frequency of a genetic variant and/or the prevalence of an environmental exposure is low. To illustrate methods for detection of gene-drug interactions on a genome-wide scale, using repeated measures data, we conduct single-study analyses and meta-analyses across studies in three large cohort studies participating in the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) consortium – the Atherosclerosis Risk in Communities (ARIC) study, the Cardiovascular Health Study (CHS), and the Rotterdam Study (RS). PMID:25297442

  13. 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.

  14. 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)

  15. The Fundamentals of Longitudinal Research: An Overview

    Directory of Open Access Journals (Sweden)

    Rajulton, Fernando

    2001-01-01

    Full Text Available EnglishThis paper outlines briefly the historical development of ideas related tolongitudinal studies and their advantages over cross-sectional studies. Then it points out a fewcomplicating factors that arise with the analysis of longitudinal data and highlights some of theapproaches adopted to manage those complicating factors and illustrated in the papers included in thisSpecial Issue. The overall aim is to promote a better understanding of the information thatlongitudinal data provide and of the suitable techniques needed to analyze such data.FrenchCet article trace brièvement le développement historique des idées liées àl’avantage des études longitudinales par rapport aux études transversales. Je préciseensuite quelques facteurs qui compliquent les analyses des données longitudinaleset je met en valeur certaines des approches adoptées pour contrôler ces facteurs etj’illustre par des exemples tirés de cette édition spéciale. Le but général estd’atteindre une meilleure compréhension de l'information que les donnéeslongitudinales fournissent et des techniques appropriées requises pour analyser detelles données.

  16. 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.

  17. Hemispheric and longitudinal asymmetries in CME occurrence

    International Nuclear Information System (INIS)

    Complete text of publication follows. A considerable amount of evidence has accumulated in support of the existence of persistent, systematic north-south (hemispherical) and longitudinal (active longitudes) asymmetries in the Sun. These features have been observed, e.g., in sunspots, solar flares, solar wind and the heliospheric magnetic field. In this work we analyze the occurrence of Coronal Mass Ejections (CMEs) observed by the SOHO LASCO instrument during the solar cycle 23. We use the manually compiled LASCO CME catalog maintained at the CDAW Data Center and for comparison the CACTus CME catalog based on automatic detection of CMEs by the CACTus software developed at SIDC in the Royal Observatory of Belgium. We discuss the temporal evolution of the occurrence rate of CMEs and study the north-south and east-west asymmetries and their temporal change. We also present a preliminary analysis of CME occurrence in a rotating coordinate system. We discuss the observations in view of the earlier evidence for hemispherical asymmetries and active longitudes.

  18. NASA Planetary Science Summer School: Longitudinal Study

    Science.gov (United States)

    Giron, Jennie M.; Sohus, A.

    2006-12-01

    NASA’s Planetary Science Summer School is a program designed to prepare the next generation of scientists and engineers to participate in future missions of solar system exploration. The opportunity is advertised to science and engineering post-doctoral and graduate students with a strong interest in careers in planetary exploration. Preference is given to U.S. citizens. The “school” consists of a one-week intensive team exercise learning the process of developing a robotic mission concept into reality through concurrent engineering, working with JPL’s Advanced Project Design Team (Team X). This program benefits the students by providing them with skills, knowledge and the experience of collaborating with a concept mission design. A longitudinal study was conducted to assess the impact of the program on the past participants of the program. Data collected included their current contact information, if they are currently part of the planetary exploration community, if participation in the program contributed to any career choices, if the program benefited their career paths, etc. Approximately 37% of 250 past participants responded to the online survey. Of these, 83% indicated that they are actively involved in planetary exploration or aerospace in general; 78% said they had been able to apply what they learned in the program to their current job or professional career; 100% said they would recommend this program to a colleague.

  19. Alternative insertions for longitudinal polarization in PEP

    International Nuclear Information System (INIS)

    During the 1975 PEP Summer Study, Garren and Kadyk studied systems for rotating the normal beam polarization into longitudinal polarization at one or more interaction regions. They developed a solution using vertical bending magnets in the long drift between Q2 and Q3 and leaving the 20-m drift region around the interaction point unencumbered. Considerable difficulty was encountered in matching the beam optics, but the possibility of such a match was demonstrated. Meanwhile, further studies of depolarizing effects have resulted in cautious optimism for the possibility of obtaining a useful degree of polarization in PEP. Consequently, it seemed worthwhile to re-examine the question of such a spin rotation system with the objectives of: improving the beam-matching optics, investigating the design requirements for the magnets and quadrupoles and defining the additional transverse space which should be reserved for the SRS in the interaction region housing. In the present note some variations of the Garren-Kadyk scheme are presented, and it is shown that the beam optics can indeed be improved considerably, along with a reduction in the complexity of the system. It is proposed that a design of this type be used as a basis for specifying the required enlargement of the appropriate straight section tunnel. The magnetic requirements for the beam transport elements appear to be reasonable, although some interesting mechanical design problems may arise. 3 refs., 4 figs., 4 tabs

  20. 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.

  1. 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.

  2. 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.)

  3. Uncorrelated Energy Spread and Longitudinal Emittance of a Photoinjector Beam

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Z; Dowell, D.; Emma, P.; Limborg-Deprey, C.; Stupakov, G.; Wu, J.; /SLAC

    2005-05-25

    Longitudinal phase space properties of a photoinjector beam are important in many areas of high-brightness beam applications such as bunch compression, transverse-to-longitudinal emittance exchange, and high-gain free-electron lasers. In this paper, we discuss both the rf and the space charge contributions to the uncorrelated energy spread of the beam generated from a laser-driven rf gun. We compare analytical expressions for the uncorrelated energy spread and the longitudinal emittance with numerical simulations and recent experimental results.

  4. 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)

  5. 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...

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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.)

  11. 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

  12. Longitudinal dispersion modeling in small streams

    Science.gov (United States)

    Pekarova, Pavla; Pekar, Jan; Miklanek, Pavol

    2014-05-01

    The environmental problems caused by the increasing of pollutant loads discharged into natural water bodies are very complex. For that reason the cognition of transport mechanism and mixing characteristics in natural streams is very important. The mathematical and numerical models have become very useful tools for solving the water management problems. The mathematical simulations based on numerical models of pollution mixing in streams can be used (for example) for prediction of spreading of accidental contaminant waves in rivers. The paper deals with the estimation of the longitudinal dispersion coefficients and with the numerical simulation of transport and transformation of accidental pollution in the small natural streams. There are different ways of solving problems of pollution spreading in open channels, in natural rivers. One of them is the hydrodynamic approach, which endeavours to understand and quantify the spreading phenomenon in a stream. The hydrodynamic models are based on advection-diffusion equation and the majority of them are one-dimensional models. Their disadvantage is inability to simulate the spread of pollution until complete dispersion of pollutant across the stream section is finished. Two-dimensional mixing models do not suffer from these limitations. On the other hand, the one-dimensional models are simpler than two-dimensional ones, they need not so much input data and they are often swifter. Three-dimensional models under conditions of natural streams are applicable with difficulties (or inapplicable) for their complexity and demands on accuracy and amount of input data. As there was mentioned above the two-dimensional models can be used also until complete dispersion of pollutant across the stream section is not finished, so we decided to apply the two-dimensional model SIRENIE. Experimental microbasin Rybarik is the part of the experimental Mostenik brook basin of IH SAS Bratislava. It was established as a Field Hydrological

  13. Populations and determinants of airborne fungi in large office buildings

    OpenAIRE

    Chao, H Jasmine; Burge, Harriet A.; Schwartz, Joel David; Milton, Donald Kirby

    2002-01-01

    Bioaerosol concentrations in office environments and their roles in causing building-related symptoms have drawn much attention in recent years. Most bioaerosol studies have been cross-sectional. We conducted a longitudinal study to examine the characteristics of airborne fungal populations and correlations with other environmental parameters in office environments. We investigated four office buildings in Boston, Massachusetts, during 1 year beginning May 1997, recruiting 21 offices with ope...

  14. 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 (...

  15. 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...

  16. 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...

  17. Causal Inference from Longitudinal Studies with Baseline Randomization

    OpenAIRE

    2008-01-01

    We describe analytic approaches for study designs that, like large simple trials, can be better characterized as longitudinal studies with baseline randomization than as either a pure randomized experiment or a purely observational study. We (i) discuss the intention-to-treat effect as an effect measure for randomized studies, (ii) provide a formal definition of causal effect for longitudinal studies, (iii) describe several methods -- based on inverse probability weighting and g-estimation --...

  18. Longitudinal Shunt Slot Excitation by Wiggly Ridge Substrate Integrated Waveguide

    OpenAIRE

    Mehdi Salemi; Mehdi Moradian; Reza Safian

    2014-01-01

    Application of a substrate integrated waveguide with wiggly ridge shape is presented for excitation longitudinal shunt slot antenna. Two main design equations for design substrate integrated waveguide structure and get parameters of structures, for longitudinal shunt slot excitation by shape wiggly ridge in substrate integrated waveguide are modified. Proposed method is used by applied the crinkle shape to ridge for ridge substrate integrated waveguide structure. This shape wiggly ridge just...

  19. The Longitudinal Research on the Effectiveness of Organizational Culture

    OpenAIRE

    Tiantong HU

    2014-01-01

    The effectiveness of the organizational culture for the organization has always been the hot spot of the theory of public organization. The cross-sectional studies of influence of organizational culture on the organizational effectiveness are incisive, but the longitudinal study is an unsubstantial aspect. This paper will summarize the research results of the effectiveness of the organizational culture, and then discuss the longitudinal influence of organizational culture by way of referring ...

  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 bunch compression study with induction voltage modulator

    OpenAIRE

    Nakayama Akira; Sakai Yasuo; Miyazaki Yoshifumi; Kikuchi Takashi; Nakajima Mitsuo; Horioka Kazuhiko

    2013-01-01

    For the beam driver of inertial confinement fusion, the technology to compress a charged particle beam in longitudinal direction is crucially important. However, the quality of the beam is expected to be deteriorated when the beam is rapidly compressed in longitudinal direction. In order to investigate the beam dynamics during bunch compression, we made a compact beam compression system and carried out beam compression experiments. In this paper, we show the background of our study and recent...

  2. Ridge and Transverse Correlation without Long-Range Longitudinal Correlation

    OpenAIRE

    Chiu, Charles B.; Hwa, Rudolph C.

    2013-01-01

    A simple phenomenological relationship between the ridge distribution in Δη and the single-particle distribution in η can be established from the PHOBOS data on both distributions. The implication points to the possibility that it is not necessary to have long-range longitudinal correlation to explain the data. An interpretation of the relationship is then developed, based on the recognition that longitudinal uncertainty of the initial configuration allows for non-Hubble-like expansion at ear...

  3. A nonparametric dynamic additive regression model for longitudinal data

    OpenAIRE

    Martinussen, Torben; Thomas H. Scheike

    2000-01-01

    In this work we study additive dynamic regression models for longitudinal data. These models provide a flexible and nonparametric method for investigating the time-dynamics of longitudinal data. The methodology is aimed at data where measurements are recorded at random time points. We model the conditional mean of responses given the full internal history and possibly time-varying covariates. We derive the asymptotic distribution for a new nonparametric least squares estimat...

  4. Analysis of Longitudinal Data with Semiparametric Estimation of Covariance Function

    OpenAIRE

    Fan, Jianqing; Huang, Tao; LI, Runze

    2007-01-01

    Improving efficiency for regression coefficients and predicting trajectories of individuals are two important aspects in analysis of longitudinal data. Both involve estimation of the covariance function. Yet, challenges arise in estimating the covariance function of longitudinal data collected at irregular time points. A class of semiparametric models for the covariance function is proposed by imposing a parametric correlation structure while allowing a nonparametric variance function. A kern...

  5. Varying Coefficient Models for Sparse Noise-contaminated Longitudinal Data

    OpenAIRE

    Şentürk, Damla; Danh V. Nguyen

    2011-01-01

    In this paper we propose a varying coefficient model for highly sparse longitudinal data that allows for error-prone time-dependent variables and time-invariant covariates. We develop a new estimation procedure, based on covariance representation techniques, that enables effective borrowing of information across all subjects in sparse and irregular longitudinal data observed with measurement error, a challenge in which there is no adequate solution currently. More specifically, sparsity is ad...

  6. 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...

  7. Ganglion Cyst of the Posterior Longitudinal Ligament Causing Lumbar Radiculopathy

    OpenAIRE

    Cho, Sung-Min; Rhee, Woo-Tack; Lee, Sang-Youl; Lee, Sang-Bok

    2010-01-01

    Degenerated conditions such as herniated disc or spinal stenosis are common etiologies of lumbar radiculopathy. Less common etiologies include spinal extradural cyst such as synovial cysts and ganglion cysts. Ganglion cyst of the posterior longitudinal ligament (PLL) of the spine is a rare entity that can result in classical sciatica. Posterior longitudinal ligament cyst has no continuity with the facet joint and has no epithelial lining. Two young male patients presented with unilateral scia...

  8. 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.

  9. 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...

  10. 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

  11. Transverse and longitudinal angular momenta of light

    Energy Technology Data Exchange (ETDEWEB)

    Bliokh, Konstantin Y., E-mail: k.bliokh@gmail.com [Center for Emergent Matter Science, RIKEN, Wako-shi, Saitama 351-0198 (Japan); Nonlinear Physics Centre, RSPhysE, The Australian National University, Canberra, ACT 0200 (Australia); Nori, Franco [Center for Emergent Matter Science, RIKEN, Wako-shi, Saitama 351-0198 (Japan); Physics Department, University of Michigan, Ann Arbor, MI 48109-1040 (United States)

    2015-08-26

    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.

  12. 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

  13. 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

  14. 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.

  15. Populous: A tool for populating ontology templates

    CERN Document Server

    Jupp, Simon; Iannone, Luigi; Klein, Julie; Owen, Stuart; Schanstra, Joost; Stevens, Robert; Wolstencroft, Katy

    2010-01-01

    We present Populous, a tool for gathering content with which to populate an ontology. Domain experts need to add content, that is often repetitive in its form, but without having to tackle the underlying ontological representation. Populous presents users with a table based form in which columns are constrained to take values from particular ontologies; the user can select a concept from an ontology via its meaningful label to give a value for a given entity attribute. Populated tables are mapped to patterns that can then be used to automatically generate the ontology's content. Populous's contribution is in the knowledge gathering stage of ontology development. It separates knowledge gathering from the conceptualisation and also separates the user from the standard ontology authoring environments. As a result, Populous can allow knowledge to be gathered in a straight-forward manner that can then be used to do mass production of ontology content.

  16. 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.

  17. 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.

  18. 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…

  19. Understanding Rural Population Loss.

    Science.gov (United States)

    McGranahan, David A.; Beale, Calvin L.

    2002-01-01

    A quarter of nonmetro counties lost population in the 1990s, but population loss was not related to poverty rate or low educational levels, perhaps because low-skill workers can no longer expect better wages in urban areas. Population loss was related to low population density and remoteness (which decrease access to services), lack of natural…

  20. Role of various kinases in muscarinic M3 receptor-mediated contraction of longitudinal muscle of rat colon

    Science.gov (United States)

    Anderson, Charles D.; Kendig, Derek M.; Al-Qudah, Mohammad; Mahavadi, Sunila; Murthy, Karnam S.; Grider, John R.

    2016-01-01

    The longitudinal muscle layer in gut is the functional opponent to the circular muscle layer during peristalsis. Differences in innervation of the layers allow for the contraction of one layer concurrently with the relaxation of the other, enabling the passage of gut contents in a controlled fashion. Differences in development have given the cells of the two layers differences in receptor populations, membrane lipid handling, and calcium handling profiles/behaviors. The contractile activity of the longitudinal muscle is largely mediated by cholinergic neural input from myenteric plexus. Activation of muscarinic receptors leads to rapid activation of several kinases including MLC kinase, ERK1/2, CaMKII and Rho kinase. Phosphorylation of myosin light chain (MLC20) by MLC kinase (MLCK) is a prerequisite for contraction in both circular and longitudinal muscle cells. In rat colonic longitudinal muscle strips, we measured muscarinic receptor-mediated contraction following incubation with kinase inhibitors. Basal tension was differentially regulated by Rho kinase, ERK1/2, CaMKII and CaMKK. Selective inhibitors of Rho kinase, ERK1/2, CaMKK/AMPK, and CaMKII each reduced carbachol-induced contraction in the innervated muscle strips. These inhibitors had no direct effect on MLCK activity. Thus unlike previously reported for isolated muscle cells where CaMKII and ERK1/2 are not involved in contraction, we conclude that the regulation of carbachol-induced contraction in innervated longitudinal muscle strips involves the interplay of Rho kinase, ERK1/2, CaMKK/AMPK, and CAMKII. PMID:25891767

  1. 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.

  2. Longitudinal associations between social anxiety symptoms and cannabis use throughout adolescence: the role of peer involvement.

    Science.gov (United States)

    Nelemans, Stefanie A; Hale, William W; Raaijmakers, Quinten A W; Branje, Susan J T; van Lier, Pol A C; Meeus, Wim H J

    2016-05-01

    There appear to be contradicting theories and empirical findings on the association between adolescent Social Anxiety Disorder (SAD) symptoms and cannabis use, suggesting potential risk as well as protective pathways. The aim of this six-year longitudinal study was to further examine associations between SAD symptoms and cannabis use over time in adolescents from the general population, specifically focusing on the potential role that adolescents' involvement with their peers may have in these associations. Participants were 497 Dutch adolescents (57 % boys; M age = 13.03 at T1), who completed annual self-report questionnaires for 6 successive years. Cross-lagged panel analysis suggested that adolescent SAD symptoms were associated with less peer involvement 1 year later. Less adolescent peer involvement was in turn associated with lower probabilities of cannabis use as well as lower frequency of cannabis use 1 year later. Most importantly, results suggested significant longitudinal indirect paths from adolescent SAD symptoms to cannabis use via adolescents' peer involvement. Overall, these results provide support for a protective function of SAD symptoms in association with cannabis use in adolescents from the general population. This association is partially explained by less peer involvement (suggesting increased social isolation) for those adolescents with higher levels of SAD symptoms. Future research should aim to gain more insight into the exact nature of the relationship between anxiety and cannabis use in adolescents from the general population, especially regarding potential risk and protective processes that may explain this relationship. PMID:26254219

  3. 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

  4. 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.

  5. 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

  6. 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. PMID:24965674

  7. 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

  8. Theoretical study of transverse-longitudinal emittance coupling

    Energy Technology Data Exchange (ETDEWEB)

    Qin, H; Davidson, R C; Chung, M; Barnard, J J; Wang, T F

    2011-04-14

    The effect of a weakly coupled periodic lattice in terms of achieving emittance exchange between the transverse and longitudinal directions is investigated using the generalized Courant-Snyder theory for coupled lattices. Recently, the concept and technique of transverse-longitudinal emittance coupling have been proposed for applications in the Linac Coherent Light Source and other free-electron lasers to reduce the transverse emittance of the electron beam. Such techniques can also be applied to the driver beams for the heavy ion fusion and beam-driven high energy density physics, where the transverse emittance budget is typically tighter than the longitudinal emittance. The proposed methods consist of one or several coupling components which completely swap the emittances of one of the transverse directions and the longitudinal direction at the exit of the coupling components. The complete emittance exchange is realized in one pass through the coupling components. In the present study, we investigate the effect of a weakly coupled periodic lattice in terms of achieving emittance exchange between the transverse and longitudinal directions. A weak coupling component is introduced at every focusing lattice, and we would like to determine if such a lattice can realize the function of emittance exchange.

  9. Longitudinal asymmetry of craters' density distributions on the icy satellites

    Science.gov (United States)

    Leliwa-Kopystynski, Jacek; Banaszek, Marcin; Wlodarczyk, Ireneusz

    2012-01-01

    Crater's density distribution versus satellitographical longitude was searched for seven icy satellites: two of Jupiter (Ganymede and Callisto) and five of Saturn (Mimas, Tethys, Dione, Rhea and Iapetus). Craters were classified according to their size. Four bins of the craters' diameter were used. Density distributions were found in the longitudinal sectors of the near-equatorial stripes that circumscribe the satellites. The size distributions (R-plots) were done independently for each of the eight longitudinal sectors of the satellites. Searching for the leading/trailing (apex/antapex) and the near-side/far-side asymmetry was done. It was found that the crater density is longitudinally asymmetric for all seven satellites being studied. However, the apex-antapex asymmetry is much less pronounced than predicted by theory of Zahnle et al. (2003), for impacts on the satellites by ecliptic comets. We conclude that the impact craters observed on the considered satellites are mostly originated from planetocentric swarm of debris. In that case longitudinal asymmetry is not expected, as stated by Horedt and Neukum (1984a, b). However, cratering longitudinal asymmetry that we observe for Mimas perfectly agrees with calculations of Alvarellos et al. (2005). It is very likely that important part of craters on Mimas were formed due to impacts of ejecta originated from crater Herschel.

  10. 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.

  11. Additional longitudinal displacement for contaminant dispersion in wetland flow

    Science.gov (United States)

    Fu, Xudong; Gao, Ran; Wu, Zi

    2016-01-01

    When there is a sudden and uniform release of contaminant over the depth of wetland, the centroid of resulted solute cloud will travel downstream at the cross-sectional mean velocity of the flow. However, if the initial release is not uniform, there will be an additional longitudinal displacement of the centroid, which is important for predicting the concentration distribution but cannot be revealed by the classical one-dimensional Taylor dispersion model. For the most typical case of an initial point source release at the free-water-surface of the wetland, an idealized case modeling accidental leakage of toxic chemicals in waters, in the present paper we analytically deduce the longitudinal displacement by the method of concentration moment. The result is then incorporated in the analytical solutions of concentration distribution, which are further verified by our numerical simulations. The effects of the longitudinal displacement on the concentration distribution are analyzed in detail. It is shown that without considering the displacement, for vertical planes close to the edges of the contaminant cloud, the analytical solution can over- or under-estimate the vertical distribution of concentration for over 20% of the maximum concentration in the plane even at a large dimensionless time of t∗ = 5 . The longitudinal displacement is shown to decrease with the increase of the important damping factor α, which characterizes the effects of vegetation in wetlands. A simple application is given at the end of this paper to illustrate the evolution of the additional longitudinal displacement.

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. Cohort Profile: Footprints in Time, the Australian Longitudinal Study of Indigenous Children.

    Science.gov (United States)

    Thurber, Katherine A; Banks, Emily; Banwell, Cathy

    2015-06-01

    Indigenous Australians experience profound levels of disadvantage in health, living standards, life expectancy, education and employment, particularly in comparison with non-Indigenous Australians. Very little information is available about the healthy development of Australian Indigenous children; the Longitudinal Study of Indigenous Children (LSIC) is designed to fill this knowledge gap.This dataset provides an opportunity to follow the development of up to 1759 Indigenous children. LSIC conducts annual face-to-face interviews with children (aged 0.5-2 and 3.5-5 years at baseline in 2008) and their caregivers. This represents between 5% and 10% of the total population of Indigenous children in these age groups, including families of varied socioeconomic and cultural backgrounds. Study topics include: the physical, social and emotional well-being of children and their caregivers; language; culture; parenting; and early childhood education.LSIC is a shared resource, formed in partnership with communities; its data are readily accessible through the Australian Government Department of Social Services (see http://dss.gov.au/lsic for data and access arrangements). As one of very few longitudinal studies of Indigenous children, and the only national one, LSIC will enable an understanding of Indigenous children from a wide range of environments and cultures. Findings from LSIC form part of a growing infrastructure from which to understand Indigenous child health. PMID:25011454

  17. 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.

  18. 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.

  19. 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…

  20. 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...

  1. 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.

  2. 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

  3. 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...

  4. 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.)

  5. Simulation of the ALS longitudinal multibunch feedback system

    International Nuclear Information System (INIS)

    Longitudinal coupled bunch growth rates in the Advanced Light Source (ALS), a 1.5 GeV electron storage ring for producing synchrotron radiation, indicate the need for damping via a feedback (FB) system. The design of the system is based on the proposed PEP-II longitudinal FB system which uses a digital filter to provide the required phase and amplitude response. We report the results of a detailed computer simulation of the FB system including single particle longitudinal beam dynamics, measured RF cavity fundamental and higher order modes, and response of major FB components such as the power amplifier and kicker. The simulation addresses issues such as required FB power and gain, noise, digital filter effects, and varying initial bunch conditions

  6. 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...

  7. Stability of longitudinal motion in intense ion beams

    International Nuclear Information System (INIS)

    Inertial confinement fusion using high energy heavy ion beams requires focussing of the igniting ion beams in longitudinal, as well as transverse, space at the pellet target. The focussing requirements set limits on the size of the beam emittances at the target, and obtaining sufficiently small emittances at the target requires sufficient stability in beam transport and acceleration from source to target, and an analysis of that stability is necessary for heavy ion fusion (HIF) accelerator design. Theoretical analysis is necessary since practical accelerator experience with high intensity non-relativistic ion beams has been limited. This analysis is particularly important for the case of a heavy ion induction linac, since previous induction linacs have been electron accelerators, and the highly relativistic electrons have negligible longitudinal motion. In this paper we present some results of our analysis of the stability of longitudinal motion

  8. Glaucoma in Asian Populations

    Science.gov (United States)

    ... Us Donate In This Section Glaucoma In Asian Populations email Send this article to a friend by ... an even more serious problem as the world population and longevity increases. The other major glaucoma type ...

  9. Estimated Glomerular Filtration Rate, All-Cause Mortality and Cardiovascular Diseases Incidence in a Low Risk Population: The MATISS Study

    OpenAIRE

    Donfrancesco, Chiara; Palleschi, Simonetta; Palmieri, Luigi; Rossi, Barbara; Lo Noce, Cinzia; Pannozzo, Fabio; Spoto, Belinda; Tripepi, Giovanni; Zoccali, Carmine; Giampaoli, Simona

    2013-01-01

    Background Chronic kidney disease (CKD) independently increases the risk of death and cardiovascular disease (CVD) in the general population. However, the relationship between estimated glomerular filtration rate (eGFR) and CVD/death risk in a general population at low risk of CVD has not been explored so far. Design Baseline and longitudinal data of 1465 men and 1459 women aged 35-74 years participating to the MATISS study, an Italian general population cohort, were used to evaluate the role...

  10. Estimating Ancestral Population Parameters

    OpenAIRE

    Wakeley, J.; Hey, J.

    1997-01-01

    The expected numbers of different categories of polymorphic sites are derived for two related models of population history: the isolation model, in which an ancestral population splits into two descendents, and the size-change model, in which a single population undergoes an instantaneous change in size. For the isolation model, the observed numbers of shared, fixed, and exclusive polymorphic sites are used to estimate the relative sizes of the three populations, ancestral plus two descendent...

  11. 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.

  12. The effect of somatic disorders on brain aging and dementia : Findings from population studies

    OpenAIRE

    Atti, Anna Rita

    2009-01-01

    This doctoral thesis investigates the effect of somatic disorders on dementia, Alzheimer s disease (AD) and brain aging in late-life. The data for the studies are provided by the Kungsholmen Project (Studies I and II) and the Faenza Project (Studies III and IV). The Kungsholmen Project is a population-based longitudinal study on aging and dementia carried out on 75+ years old people, living in Stockholm, Sweden. The Faenza Project is a cross-sectional population-based study ...

  13. The rational use of drugs in a population of very old persons

    OpenAIRE

    Giron, Maria Stella T

    2002-01-01

    This thesis investigated the use of drugs in a population of very old persons. The pattems of use, particularly of psychotropic drugs, and its appropriateness were assessed. Drug use was also assessed according to dementia diagnosis and in relation to the presence of psychiatric illnesses. Inasmuch as there is extensive literature on drug use in older persons, data on the very old is scant. The Kungsholmen project, a longitudinal population-based study on aging, provided us ...

  14. Modeling Exponential Population Growth

    Science.gov (United States)

    McCormick, Bonnie

    2009-01-01

    The concept of population growth patterns is a key component of understanding evolution by natural selection and population dynamics in ecosystems. The National Science Education Standards (NSES) include standards related to population growth in sections on biological evolution, interdependence of organisms, and science in personal and social…

  15. Teaching Population Geography.

    Science.gov (United States)

    Carey, George W.; Schwartzberg, Julie

    Written under the sponsorship of the Population Council, with the financial support of the Population Instructional Materials Project, this work is intended to provide the thoughtful teacher of the social sciences with some suggestions and techniques for introducing population study to students in terms of concrete case studies which explore the…

  16. Controlling Population with Pollution

    Science.gov (United States)

    Browne, Joseph

    2010-01-01

    Population models are often discussed in algebra, calculus, and differential equations courses. In this article we will use the human population of the world as our application. After quick looks at two common models we'll investigate more deeply a model which incorporates the negative effect that accumulated pollution may have on population.

  17. 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

  18. Rapidly- growing firms and their main characteristics: a longitudinal study from United States

    DEFF Research Database (Denmark)

    Keen, Christian; etemad, hamid

    2011-01-01

    This paper explores the topic of high-growth phenomenon and its agents. High-growth enterprises are primarily small and medium sized firms that attain very high-growth rates for at least five years. The paper presents a review of the pertinent literature to guide its formulation of hypotheses con...... scholarly research and public policy analysis and formulation....... concerning the theoretical relations between high-growth and location, size and temporal characteristics of the high-growth enterprises. Using non parametric tests, we analyze a 21-year longitudinal database of privately held rapidly growing enterprises from the USA. This analysis indicates that these firms...... are relatively smaller enterprises and their high growth rates are not restricted to a particular location, industrial region, size or time period. The findings of this analysis point to a population of high-growth enterprises with diverse locations, sizes and times with important implications for...

  19. 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

  20. 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.

  1. Household Composition and Longitudinal Health Outcomes for Older Mexican Return Migrants.

    Science.gov (United States)

    Mudrazija, Stipica; López-Ortega, Mariana; Vega, William A; Gutiérrez Robledo, Luis Miguel; Sribney, William

    2016-04-01

    Mexican return migrant population is increasing, yet our knowledge about their lives after resettlement in Mexico remains fragmentary. Using 2001-2012 longitudinal data from the Mexican Health and Aging Study, we investigate difference in household composition for older migrants who returned from the United States compared to nonmigrants. Furthermore, we fit a Cox proportional hazards model to assess the relationship between household composition and health and functional trajectories of return migrants and nonmigrants. The results indicate that return migrants with long duration of U.S. stay have different household composition than nonmigrants or short-term migrants: On average, they have smaller household size, including fewer females who may be available to offer assistance to older adults. Presence of middle-age females in the household has positive effects on health and functional trajectories. We highlight implications of this research for policy makers in Mexico and the United States. PMID:26966255

  2. 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.

  3. Longitudinal vector form factors in weak decays of nuclei

    International Nuclear Information System (INIS)

    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

  4. 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.)

  5. Longitudinal bunch compression study with induction voltage modulator

    Directory of Open Access Journals (Sweden)

    Nakayama Akira

    2013-11-01

    Full Text Available For the beam driver of inertial confinement fusion, the technology to compress a charged particle beam in longitudinal direction is crucially important. However, the quality of the beam is expected to be deteriorated when the beam is rapidly compressed in longitudinal direction. In order to investigate the beam dynamics during bunch compression, we made a compact beam compression system and carried out beam compression experiments. In this paper, we show the background of our study and recent progress of the beam compression experiments.

  6. 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.

  7. 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.

  8. Measurement of Longitudinal Electron Diffusion in Liquid Argon

    CERN Document Server

    Li, Yichen; Thorn, Craig; Qian, Xin; Diwan, Milind; Joshi, Jyoti; Kettell, Steve; Morse, William; Rao, Triveni; Stewart, Jim; Tang, Wei; Viren, Brett

    2015-01-01

    We report the measurement of longitudinal electron diffusion coefficients in liquid argon for electric fields between 100 and 2000 V/cm with a gold photocathode as a bright electron source. The measurement principle, apparatus, and data analysis are described. Our results, which are consistent with previous measurements in the region between 100 to 350 V/cm [1] , are systematically higher than the prediction of Atrazhev-Timoshkin[2], and represent the world's best measurement in the region between 350 to 2000 V/cm. The quantum efficiency of the gold photocathode, the drift velocity and longitudinal diffusion coefficients in gas argon are also presented.

  9. 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

  10. Online and Offline Recruitment of Young Women for a Longitudinal Health Survey: Findings From the Australian Longitudinal Study on Women’s Health 1989-95 Cohort

    Science.gov (United States)

    Powers, Jennifer; Anderson, Amy E; Townsend, Natalie; Harris, Melissa L; Tuckerman, Ryan; Pease, Stephanie; Mishra, Gita; Byles, Julie

    2015-01-01

    Background In 2012, we set out to recruit a cohort of at least 10,000 women aged 18-23 from across Australia. With recent research demonstrating the inadequacy of traditional approaches to recruiting women in this age group, we elected to conduct open recruiting. Objective Our aim was to report on the overall success of open recruiting and to evaluate the relative success of a variety of recruitment methods in terms of numbers and demographics. Methods We used referrals, Facebook, formal advertising, and incentives in order to recruit the cohort. Results In all, 17,069 women were recruited for the longitudinal online survey, from 54,685 initiated surveys. Of these women, most (69.94%, n=11,799) who joined the longitudinal cohort were recruited via Facebook, 12.72% (n=2145) via the fashion promotion, 7.02% (n=1184) by referral, 4.9% (n=831) via other Web activities, and 5.4% (n=910) via traditional media. Conclusions Facebook was by far the most successful strategy, enrolling a cohort of women with a similar profile to the population of Australian women in terms of age, area of residence, and relationship status. Women recruited via fashion promotion were the least representative. All strategies underrepresented less educated women—a finding that is consistent with more traditional means of recruiting. In conclusion, flexibility in recruitment design, embracing new and traditional media, adopting a dynamic responsive approach, and monitoring the results of recruiting in terms of sample composition and number recruited led to the successful establishment of a new cohort. PMID:25940876

  11. Research Network of Tehran Defined Population: Methodology and Establishment

    Directory of Open Access Journals (Sweden)

    Ali-Asghar Kolahi

    2015-12-01

    Full Text Available Background: We need a defined population for determining prevalence and incidence of diseases, as well as conducting interventional, cohort and longitudinal studies, calculating correct and timely public health indicators, assessing actual health needs of community, performing educational programs and interventions to promote healthy lifestyle, and enhancing quality of primary health services.The objective of this project was to determine a defined population which is representative of Tehran, the Capital of Iran. This article reports the methodology and establishment of the research network of Tehran defined population.Methods: This project started by selecting two urban health centers from each of the five district health centers affiliated to Shahid Beheshti University of Medical Sciences in 2012. Inside each selected urban health center, one defined population research station was established. Two new centers have been added during 2013 and 2014. For the time being, the number of the covered population of the network has reached 40000 individuals. The most important criterion for the defined population has been to be representative of the population of Tehran. For this, we selected two urban health centers from 12 of 22 municipality districts and from each of the five different socioeconomic of Greater Tehran. Merely 80000 individuals in neighborhoods of each defined population research station were considered as control group of the project.Findings: Totally we selected 12 defined population research stations and their under-covered population developed a defined population which is representative of Tehran population.Conclusion: a population lab is ready now in metropolitan of Tehran.

  12. 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.

  13. Personal, behavioral and socio-environmental predictors of overweight incidence in young adults: 10-yr longitudinal findings

    OpenAIRE

    Quick, Virginia; Wall, Melanie; Larson, Nicole; Haines, Jess; Neumark-Sztainer, Dianne

    2013-01-01

    Background The objective of this study was to identify 10-year longitudinal predictors of overweight incidence during the transition from adolescence to young adulthood. Methods Data were from Project EAT (Eating and Activity in Teens and Young Adults). A diverse, population-based cohort (N = 2,134) completed baseline surveys in 1998–1999 (mean age = 15.0±1.6, ‘adolescence’) and follow-up surveys in 2008–2009 (mean age = 25.4±1.7, ‘young adulthood’). Surveys assessed personal, behavioral and ...

  14. 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 %...

  15. A comparison of power analysis methods for evaluating effects of a predictor on slopes in longitudinal designs with missing data.

    Science.gov (United States)

    Wang, Cuiling; Hall, Charles B; Kim, Mimi

    2015-12-01

    In many longitudinal studies, evaluating the effect of a binary or continuous predictor variable on the rate of change of the outcome, i.e. slope, is often of primary interest. Sample size determination of these studies, however, is complicated by the expectation that missing data will occur due to missed visits, early drop out, and staggered entry. Despite the availability of methods for assessing power in longitudinal studies with missing data, the impact on power of the magnitude and distribution of missing data in the study population remain poorly understood. As a result, simple but erroneous alterations of the sample size formulae for complete/balanced data are commonly applied. These 'naive' approaches include the average sum of squares and average number of subjects methods. The goal of this article is to explore in greater detail the effect of missing data on study power and compare the performance of naive sample size methods to a correct maximum likelihood-based method using both mathematical and simulation-based approaches. Two different longitudinal aging studies are used to illustrate the methods. PMID:22357710

  16. GEE for longitudinal ordinal data: Comparing R-geepack, R-multgee, R-repolr, SAS-GENMOD, SPSS-GENLIN

    OpenAIRE

    Nooraee, Nazanin; Molenberghs, Geert; van den Heuvel, Edwin R.

    2014-01-01

    Studies in epidemiology and social sciences are often longitudinal and outcome measures are frequently obtained by questionnaires in ordinal scales. To understand the relationship between explanatory variables and outcome measures, generalized estimating equations can be applied to provide a population-averaged interpretation and address the correlation between outcome measures. It can be performed by different software packages, but a motivating example showed differences in the output. This...

  17. Progressive brain changes in children and adolescents with early-onset psychosis:A meta-analysis of longitudinal MRI studies

    OpenAIRE

    Fraguas, David; Díaz-Caneja, Covadonga M.; Pina-Camacho, Laura; Janssen, Joost; Arango, Celso

    2016-01-01

    Background: Studies on longitudinal brain volume changes in patients with early-onset psychosis (EOP) are particularly valuable for understanding the neurobiological basis of brain abnormalities associated with psychosis. However, findings have not been consistent across studies in this population. We aimed to conduct a meta-analysis on progressive brain volume changes in children and adolescents with EOP. Methods: A systematic literature search of magnetic resonance imaging (MRI) studies com...

  18. Is density of neighbourhood restaurants associated with BMI in rural Chinese adults? A longitudinal study from the China Health and Nutrition Survey

    OpenAIRE

    Du, Wenwen; Su, Chang; Wang, Huijun; Wang, Zhihong; Wang, Youfa; Zhang, Bing

    2014-01-01

    Objectives The neighbourhood availability of restaurants has been linked to the weight status. However, little is known regarding the relation between access to restaurant and obesity among the Chinese population. This study aims to explore the relationship between neighbourhood restaurant density and body mass index (BMI) in rural China. Design A longitudinal study using data from the China Health and Nutrition Survey (CHNS) was conducted. Participants aged 18 and older from the 2004, 2006, ...

  19. Early-onset depressive disorders,related mental health disorders and substance use-A prospective : longitudinal study of Finnish twins born 1983-1987

    OpenAIRE

    Sihvola, Elina

    2010-01-01

    Early-onset psychiatric illnesses effects scatter to academic achievements as well as functioning in familial and social environments. From a public health point of view, depressive disorders are the most significant mental health disorders that begin in adolescence. Using prospective and longitudinal design, this study aimed to increase the understanding of early-onset depressive disorders, related mental health disorders and developing substance use in a large population-derived sample of ...

  20. [Population policies and population trends in China].

    Science.gov (United States)

    Pressat, R

    1983-04-01

    Although relatively little has been known about the Chinese population in recent centuries, figures are available for more remote times. In the year 2 the Chinese population was recorded at 60 million. In 1928, when the last pre-Revolution census was conducted, China had a population of 475 million. The population was not believed to have grown very much due to internal disorders, war, and foreigh invasion, but the 1953 census counted 582 million to which were added 18 million to include Taiwan and overseas Chinese. The figure of 600 million appears to mark the beginning of concern over demographic problems. The crude birth rate was estimated at 37/1000 and the death rate at 17/1000. The 1953 census was conducted with Soviet aid and was given some publicity. The period 1953-58 was marked by a mortality decline and a steady fertility rate, but the population is believed to have declined from 647 million in 1958 to 643 million in 1962, the end of the Great Leap Forward. A census suppressed until recently gave a total of 694 million for 1964. Population growth was considerable from 1961-66. In the 1st part of the Cultural Revolution from 1966-70, no effort was made to control population growth; in 1971, the crude birth rate was estimated at 30-35/1000, the mortality rate was 8/1000, and the growth rate was 2.6%. 1971-79 marked the 1st phase of birth limitation, which became more pressing with time. The population was counted at 1 billion 8 million in 1982, with a birth rate of 21/1000, a death rate of 6/1000, and a growth rate of 1.5%. Because of China's comprehensive system of population registration, the results of the 1982 census were not completely unexpected. Wide differences in growth rates were noted between provinces, and the minorities grew at a faster rate than the Han majority. Immediately after the Revolution, population was relatively neglected in China in favor of greater attention to economic growth. The 1st warnings about the consequences of overly