Sample records for additional longitudinal studies

  1. Trajectories of Mental Health over 16 Years amongst Young Adult Women: The Australian Longitudinal Study on Women's Health

    ERIC Educational Resources Information Center

    Holden, Libby; Ware, Robert S.; Lee, Christina

    2016-01-01

    This article used data from 5,171 young women participating in the Australian Longitudinal Study on Women's Health, a nationally representative longitudinal cohort study, to identify longitudinal trajectory patterns of mental health across 6 surveys over 16 years of early adulthood, from age 18-23 to age 34-39. In addition, we identified both…

  2. The Importance of Additive Reasoning in Children's Mathematical Achievement: A Longitudinal Study

    ERIC Educational Resources Information Center

    Ching, Boby Ho-Hong; Nunes, Terezinha

    2017-01-01

    This longitudinal study examines the relative importance of counting ability, additive reasoning, and working memory in children's mathematical achievement (calculation and story problem solving). In Hong Kong, 115 Chinese children aged 6 years old participated in 2 waves of assessments (T1 = first grade and T2 = second grade). Multiple regression…

  3. Accounting for dropout reason in longitudinal studies with nonignorable dropout.

    PubMed

    Moore, Camille M; MaWhinney, Samantha; Forster, Jeri E; Carlson, Nichole E; Allshouse, Amanda; Wang, Xinshuo; Routy, Jean-Pierre; Conway, Brian; Connick, Elizabeth

    2017-08-01

    Dropout is a common problem in longitudinal cohort studies and clinical trials, often raising concerns of nonignorable dropout. Selection, frailty, and mixture models have been proposed to account for potentially nonignorable missingness by relating the longitudinal outcome to time of dropout. In addition, many longitudinal studies encounter multiple types of missing data or reasons for dropout, such as loss to follow-up, disease progression, treatment modifications and death. When clinically distinct dropout reasons are present, it may be preferable to control for both dropout reason and time to gain additional clinical insights. This may be especially interesting when the dropout reason and dropout times differ by the primary exposure variable. We extend a semi-parametric varying-coefficient method for nonignorable dropout to accommodate dropout reason. We apply our method to untreated HIV-infected subjects recruited to the Acute Infection and Early Disease Research Program HIV cohort and compare longitudinal CD4 + T cell count in injection drug users to nonusers with two dropout reasons: anti-retroviral treatment initiation and loss to follow-up.

  4. Giftedness, Trauma, and Development: A Qualitative, Longitudinal Case Study

    ERIC Educational Resources Information Center

    Peterson, Jean Sunde

    2014-01-01

    A qualitative, longitudinal, phenomenological case study explored how a gifted female experienced various life events and aspects of development during adolescence and young adulthood (ages 15-30 years), particularly as related to multiple traumatic experiences, which were revealed late in the first year of the study. Additional experiences, well…

  5. Factors Influencing the Research Participation of Adults with Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Haas, Kaaren; Costley, Debra; Falkmer, Marita; Richdale, Amanda; Sofronoff, Kate; Falkmer, Torbjörn

    2016-01-01

    Recruiting adults with autism spectrum disorders (ASD) into research poses particular difficulties; longitudinal studies face additional challenges. This paper reports on a mixed methods study to identify factors influencing the participation in longitudinal autism research of adults with ASD, including those with an intellectual disability, and…

  6. Attachment from Infancy to Adulthood: The Major Longitudinal Studies

    ERIC Educational Resources Information Center

    Grossmann, Klaus E., Ed.; Grossmann, Karin, Ed.; Waters, Everett, Ed.

    2005-01-01

    This volume provides unique and valuable firsthand accounts of the most important longitudinal studies of attachment. Presented are a range of research programs that have broadened the understanding of early close relationships and their role in individual adaptation throughout life. In addition to discussing the findings that emerged from each…

  7. The Lifelong Productivity of the Female Researchers in Terman's Genetic Studies of Genius Longitudinal Study.

    ERIC Educational Resources Information Center

    Rogers, Karen B.

    1999-01-01

    A survey investigated the lifelong productivity of 30 women research associates who worked on a longitudinal study of gifted children. Most of the women appear to have had satisfying personal lives in addition to productive professional careers. Personal responsibilities appear to have affected levels of productivity more than societal…

  8. Longitudinal Course of Depression Scores with and without Insomnia in Non-Depressed Individuals: A 6-Year Follow-Up Longitudinal Study in a Korean Cohort

    PubMed Central

    Suh, Sooyeon; Kim, Hyun; Yang, Hae-Chung; Cho, Eo Rin; Lee, Seung Ku; Shin, Chol

    2013-01-01

    Study Objective: This is a population-based longitudinal study that followed insomnia symptoms over a 6-year period in non-depressed individuals. The purpose of the study was to (1) investigate the longitudinal course of depression based on number of insomnia episodes; and (2) describe longitudinal associations between insomnia and depression, and insomnia and suicidal ideation. Design: Population-based longitudinal study. Setting: Community-based sample from the Korean Genome and Epidemiology Study (KoGES). Participants: 1,282 non-depressed individuals (44% male, mean age 52.3 ± 7.14 years) Measurements and Results: This study prospectively assessed insomnia, depression, and suicidal ideation with 4 time points. Individuals were classified into no insomnia (NI), single episode insomnia (SEI), and persistent insomnia (PI; ≥ insomnia at 2+ time points) groups based on number of times insomnia was indicated. Mixed effects modeling indicated that depression scores increased significantly faster in the PI group compared to the NI (P < 0.001) and SEI (P = 0.02) groups. Additionally, the PI group had significantly increased odds of depression as compared to NI or SEI (OR 2.44, P = 0.001) groups, with 18.7% meeting criteria for depression compared to the NI (5.3%) and SEI (11.6%) groups at end point. The PI group also had significantly increased odds of suicidal ideation as compared to NI or SEI (OR 1.86, P = 0.002) groups. Conclusions: Persistent insomnia significantly increases the rate in which depression occurs over time in non-depressed individuals, which ultimately leads to higher risk for depression. Additionally, having persistent insomnia also increased the risk of suicidal ideation. Citation: Suh S; Kim H; Yang HC; Cho ER; Lee SK; Shin C. Longitudinal course of depression scores with and without insomnia in non-depressed individuals: a 6-year follow-up longitudinal study in a Korean cohort. SLEEP 2013;36(3):369-376. PMID:23449814

  9. Anxiety Sensitivity and Panic Attacks: A 1-Year Longitudinal Study

    ERIC Educational Resources Information Center

    Li, Wen; Zinbarg, Richard E.

    2007-01-01

    The hypothesis that anxiety sensitivity (AS) is a risk factor for panic genesis has obtained compelling support, but the clinical/practical importance of AS in panic genesis has been questioned. In addition, the association between panic experience and AS increase has not been clearly demonstrated. Through this 1-year longitudinal study among…

  10. Future orientation, impulsivity, and problem behaviors: a longitudinal moderation model.

    PubMed

    Chen, Pan; Vazsonyi, Alexander T

    2011-11-01

    In the current study, based on a sample of 1,873 adolescents between 11.4 and 20.9 years of age from the first 3 waves of the National Longitudinal Study of Adolescent Health, we investigated the longitudinal effects of future orientation on levels of and developmental changes in problem behaviors, while controlling for the effects by impulsivity; we also tested the moderating effects by future orientation on the impulsivity-problem behaviors link over time. Additionally, we examined future orientation operationalized by items measuring education, marriage, and life domains. Findings based on growth curve analyses provided evidence of longitudinal effects by education and life future orientation on both levels of and developmental changes in problem behaviors; the effect of marriage future orientation was not significant for either test. In addition, only life future orientation moderated the effect by impulsivity on levels of problem behaviors over time. More specifically, impulsivity had a weaker effect on levels of problem behaviors over time for adolescents who reported higher levels of life future orientation.

  11. The impact of extended longitudinal observation on the assessment of personality disorders.

    PubMed

    Pedersen, G; Karterud, S; Hummelen, B; Wilberg, T

    2013-11-01

    Multiple sources of information are necessary for a valid assessment of personality disorders (PDs). This study investigates the impact of longitudinal observation. The sample comprised 1217 patients from 15 different treatment units. PDs were assessed at admission to treatment using the Structured Clinical Interview for DSM-IV Axis II Personality Disorders (SCID-II) and additional clinical information (best estimate diagnosis). After approximately 18 weeks of treatment, the SCID-II protocols were re-examined at clinical conferences and the diagnostic status reassessed on the basis of longitudinal observations in multiple group situations (longitudinal, expert, all data principle). Using this procedure, 78% of the patients' diagnostic criteria sets were changed, and 32% of patients' diagnostic statuses were changed. Many (32%) patients who were evaluated initially as not having a PD received a PD diagnosis after re-examination. The information provided by customary clinical assessment has important limitations, and longitudinal observation provides additional information that may change the diagnostic status in approximately one-third of PD cases. Copyright © 2013 John Wiley & Sons, Ltd.

  12. The State of PR Graduate Curriculum as We Know It: A Longitudinal Analysis

    ERIC Educational Resources Information Center

    Briones, Rowena L.; Toth, Elizabeth L.

    2013-01-01

    This longitudinal content analysis study uses the Commission on Public Relations Education's 2006 report as a benchmark to determine whether master's education in public relations has evolved over the past decade. Findings show a lack of uniformity across the 75 programs studied. In addition, there is a lack of adherence to the Commission on…

  13. Academic and Work-Related Burnout: A Longitudinal Study of Working Undergraduate University Business Students

    ERIC Educational Resources Information Center

    Galbraith, Craig S.; Merrill, Gregory B.

    2012-01-01

    We examined the interaction between academic burnout and work-related burnout for a sample of working undergraduate university students. Using a longitudinal design we found that the factors of burnout (Exhaustion, Cynicism, and Efficacy) change significantly over the semester. In addition, the study suggests there are distinct differences in how…

  14. Anger, Stress Proliferation, and Depressed Mood among Parents of Children with ASD: A Longitudinal Replication

    ERIC Educational Resources Information Center

    Benson, Paul R.; Karlof, Kristie L.

    2009-01-01

    "Stress proliferation" (the tendency for stressors to create additional stressors) has been suggested as an important contributor to depression among caregivers. The present study utilized longitudinal data from 90 parents of children with ASD to replicate and extend a prior cross-sectional study on stress proliferation by Benson (J Autism Develop…

  15. A Longitudinal Study on Mathematics Teaching Efficacy: Which Factors (Un)Support the Development?

    ERIC Educational Resources Information Center

    Isiksal-Bostan, Mine

    2016-01-01

    The aim of this longitudinal study was to examine prospective teachers' mathematics teaching efficacy belief during their enrollment in teacher education program and at the end of their first year of teaching. In addition, the factors that enhance or inhibit participants' efficacy belief and how these factors affect their mathematics teaching…

  16. The Effects of Preschool Attendance & Kindergarten Schedule: Kindergarten through Grade Four. A Longitudinal Research Study.

    ERIC Educational Resources Information Center

    Ohio State Dept. of Education, Columbus. Div. of Early Childhood Education.

    This longitudinal study examined the effects on children of three kindergarten schedules: half day, alternate day, and full day. A secondary purpose was to examine the relationship between preschool attendance and subsequent school performance. Two additional variables thought to be related to school success were also explored: children's gender,…

  17. Longitudinal Study Transformed Onboarding Nurse Graduates.

    PubMed

    Slate, Kimberly A; Stavarski, Debra H; Romig, Barbara J; Thacker, Karen S

    The outcomes of a longitudinal research study on a nurse residency program indicated improvement in the onboarding experience for new graduate nurses. Practice changes and implications for nursing professional development practitioners resulting from the study include the number and orientation of preceptors, program length standardization, and improvement of emergency clinical response education. Additional research studies were implemented to further explore issues novice nurses and their proficient registered nurse colleagues experience throughout the organization.

  18. Longitudinal Stability in Genetic Effects on Children's Conversational Language Productivity

    ERIC Educational Resources Information Center

    DeThorne, Laura Segebart; Harlaar, Nicole; Petrill, Stephen A.; Deater-Deckard, Kirby

    2012-01-01

    Purpose: The authors examined the longitudinal stability of genetic and environmental influences on children's productive language sample measures during the early school-age years. Method: Twin study methodology with structural equation modeling was used to derive univariate estimates of additive genetic (A), shared environmental (C), and…

  19. Excessive Reassurance Seeking, Hassles, and Depressive Symptoms in Children of Affectively Ill Parents: A Multiwave Longitudinal Study

    ERIC Educational Resources Information Center

    Abela, John R. Z.; Zuroff, David C.; Ho, Moon-Ho R.; Adams, Philippe; Hankin, Benjamin L.

    2006-01-01

    The current study examined whether excessive reassurance seeking serves as a vulnerability factor to depression in a sample of high-risk youth using a multiwave longitudinal design. At Time 1, 140 children (aged 6-14) of affectively disordered parents completed measures assessing reassurance seeking and depressive symptoms. In addition, every 6…

  20. Estimating gestational age at birth from fundal height and additional anthropometrics: a prospective cohort study.

    PubMed

    Pugh, S J; Ortega-Villa, A M; Grobman, W; Newman, R B; Owen, J; Wing, D A; Albert, P S; Grantz, K L

    2018-02-23

    Accurate assessment of gestational age (GA) is critical to paediatric care, but is limited in developing countries without access to ultrasound. Our objectives were to assess the accuracy of prediction of GA at birth and preterm birth classification using routinely collected anthropometry measures. Prospective cohort study. United States. A total of 2334 non-obese and 468 obese pregnant women. Enrolment GA was determined based on last menstrual period, confirmed by first-trimester ultrasound. Maternal anthropometry and fundal height (FH) were measured by a standardised protocol at study visits; FH alone was additionally abstracted from medical charts. Neonatal anthropometry measurements were obtained at birth. To estimate GA at delivery, we developed three predictor models using longitudinal FH alone and with maternal and neonatal anthropometry. For all predictors, we repeatedly sampled observations to construct training (60%) and test (40%) sets. Linear mixed models incorporated longitudinal maternal anthropometry and a shared parameter model incorporated neonatal anthropometry. We assessed models' accuracy under varied scenarios. Estimated GA at delivery. Prediction error for various combinations of anthropometric measures ranged between 13.9 and 14.9 days. Longitudinal FH alone predicted GA within 14.9 days with relatively stable prediction errors across individual race/ethnicities [whites (13.9 days), blacks (15.1 days), Hispanics (15.5 days) and Asians (13.1 days)], and correctly identified 75% of preterm births. The model was robust to additional scenarios. In low-risk, non-obese women, longitudinal FH measures alone can provide a reasonably accurate assessment of GA when ultrasound measures are not available. Longitudinal fundal height alone predicts gestational age at birth when ultrasound measures are unavailable. © 2018 Royal College of Obstetricians and Gynaecologists.

  1. Polydactylous Transverse Erythronychia: Report of a Patient with Multiple Horizontal Red Bands Affecting the Fingernails.

    PubMed

    Chang, Carina; Beutler, Bryce D; Cohen, Philip R

    2017-06-01

    Redness of the nail plate-erythronychia-is a common condition involving one or multiple digits. It may affect the entire nail or present as longitudinal red bands that extend from the proximal nail fold to the distal tip of the nail plate. Rarely, red bands may traverse the nail bed horizontally. Although erythronychia is often idiopathic, it has also been associated with amyloidosis, Darier's disease, lichen planus, and various other cutaneous conditions. We describe the clinical features of a 64-year-old Caucasian man who presented with transverse and longitudinal erythronychia affecting his fingernails. In addition, we review the classification of erythronychia and summarize the acute and chronic conditions that have been associated with this clinical finding. The features of a man with polydactylous transverse and longitudinal erythronychia are presented. In addition, PubMed was used to search the following terms: erythronychia, longitudinal erythronychia, red lunulae, and subungual. All papers were reviewed, and relevant articles, along with their references, were evaluated. Informed consent was obtained from the patient for being included in the study. A 64-year-old Caucasian man with a past medical history significant for testicular cancer and pulmonary embolism presented with multiple horizontal pink-red bands affecting his fingernails. The discoloration was most prominent in the region distal to the lunula. In addition, the nails of the fifth digit of his left hand and third digit of his right hand featured longitudinal red bands extending from the distal curvature of the lunula to the free edge of the nail plate. A diagnosis of polydactylous longitudinal and transverse erythronychia, based on the clinical presentation, was established. Our patient's red bands were asymptomatic and he was not concerned about the cosmetic appearance of his nails; therefore, no additional investigation or treatment was required. Polydactylous transverse erythronychia is a rare condition characterized by the development of horizontal red bands affecting the fingernails or toe nails. It has only been previously described in a man with multiple system atrophy. In our patient, both transverse and longitudinal red bands were present simultaneously. Therefore, it is possible that horizontal erythronychia is an early clinical manifestation of longitudinal erythronychia.

  2. Longitudinal Follow-up of Factors Associated with Food Selectivity in Children with Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Suarez, Michelle A.; Nelson, Nickola W.; Curtis, Amy B.

    2014-01-01

    The objective of this study was to examine food selectivity in children with autism spectrum disorders longitudinally. Additionally explored were the stability of the relationship between food selectivity and sensory over-responsivity from time 1 to time 2 and the association between food selectivity and restricted and repetitive behavior at time…

  3. Longitudinal Relationships Between Productive Activities and Functional Health in Later Years: A Multivariate Latent Growth Curve Modeling Approach.

    PubMed

    Choi, Eunhee; Tang, Fengyan; Kim, Sung-Geun; Turk, Phillip

    2016-10-01

    This study examined the longitudinal relationships between functional health in later years and three types of productive activities: volunteering, full-time, and part-time work. Using the data from five waves (2000-2008) of the Health and Retirement Study, we applied multivariate latent growth curve modeling to examine the longitudinal relationships among individuals 50 or over. Functional health was measured by limitations in activities of daily living. Individuals who volunteered, worked either full time or part time exhibited a slower decline in functional health than nonparticipants. Significant associations were also found between initial functional health and longitudinal changes in productive activity participation. This study provides additional support for the benefits of productive activities later in life; engagement in volunteering and employment are indeed associated with better functional health in middle and old age. © The Author(s) 2016.

  4. The Longitudinal Stability and Dynamics of Group Membership in the Dual-Factor Model of Mental Health: Psychosocial Predictors of Mental Health

    ERIC Educational Resources Information Center

    Kelly, Ryan M.; Hills, Kimberly J.; Huebner, E. Scott; McQuillin, Samuel D.

    2012-01-01

    This study examined the longitudinal stability and dynamics of group membership within the Greenspoon and Sakflofske's dual-factor model of mental health. This expanded model incorporates information about subjective well-being (SWB), in addition to psychopathological symptoms, to better identify the mental health status and current functioning of…

  5. Association between media use in adolescence and depression in young adulthood: a longitudinal study.

    PubMed

    Primack, Brian A; Swanier, Brandi; Georgiopoulos, Anna M; Land, Stephanie R; Fine, Michael J

    2009-02-01

    Although certain media exposures have been linked to the presence of psychiatric conditions, few studies have investigated the association between media exposure and depression. To assess the longitudinal association between media exposure in adolescence and depression in young adulthood in a nationally representative sample. Longitudinal cohort study. We used the National Longitudinal Survey of Adolescent Health (Add Health) to investigate the relationship between electronic media exposure in 4142 adolescents who were not depressed at baseline and subsequent development of depression after 7 years of follow-up. Main Outcome Measure Depression at follow-up assessed using the 9-item Center for Epidemiologic Studies-Depression Scale. Of the 4142 participants (47.5% female and 67.0% white) who were not depressed at baseline and who underwent follow-up assessment, 308 (7.4%) reported symptoms consistent with depression at follow-up. Controlling for all covariates including baseline Center for Epidemiologic Studies-Depression Scale score, those reporting more television use had significantly greater odds of developing depression (odds ratio [95% confidence interval], 1.08 [1.01-1.16]) for each additional hour of daily television use. In addition, those reporting more total media exposure had significantly greater odds of developing depression (1.05 [1.0004-1.10]) for each additional hour of daily use. We did not find a consistent relationship between development of depressive symptoms and exposure to videocassettes, computer games, or radio. Compared with young men, young women were less likely to develop depression given the same total media exposure (odds ratio for interaction term, 0.93 [0.88-0.99]). Television exposure and total media exposure in adolescence are associated with increased odds of depressive symptoms in young adulthood, especially in young men.

  6. Positive Parenting in Adolescence and Its Relation to Low Point Narration and Identity Status in Emerging Adulthood: A Longitudinal Analysis

    ERIC Educational Resources Information Center

    Dumas, Tara M.; Lawford, Heather; Tieu, Thanh-Thanh; Pratt, Michael W.

    2009-01-01

    In this longitudinal study, we examined identity development using the life story model (McAdams, 2001), in addition to a traditional identity status approach, in order to explore the association between perceived parenting in adolescence and the subsequent quality of life story narration in emerging adulthood. Participants (N = 100) were given a…

  7. LADES: a software for constructing and analyzing longitudinal designs in biomedical research.

    PubMed

    Vázquez-Alcocer, Alan; Garzón-Cortes, Daniel Ladislao; Sánchez-Casas, Rosa María

    2014-01-01

    One of the most important steps in biomedical longitudinal studies is choosing a good experimental design that can provide high accuracy in the analysis of results with a minimum sample size. Several methods for constructing efficient longitudinal designs have been developed based on power analysis and the statistical model used for analyzing the final results. However, development of this technology is not available to practitioners through user-friendly software. In this paper we introduce LADES (Longitudinal Analysis and Design of Experiments Software) as an alternative and easy-to-use tool for conducting longitudinal analysis and constructing efficient longitudinal designs. LADES incorporates methods for creating cost-efficient longitudinal designs, unequal longitudinal designs, and simple longitudinal designs. In addition, LADES includes different methods for analyzing longitudinal data such as linear mixed models, generalized estimating equations, among others. A study of European eels is reanalyzed in order to show LADES capabilities. Three treatments contained in three aquariums with five eels each were analyzed. Data were collected from 0 up to the 12th week post treatment for all the eels (complete design). The response under evaluation is sperm volume. A linear mixed model was fitted to the results using LADES. The complete design had a power of 88.7% using 15 eels. With LADES we propose the use of an unequal design with only 14 eels and 89.5% efficiency. LADES was developed as a powerful and simple tool to promote the use of statistical methods for analyzing and creating longitudinal experiments in biomedical research.

  8. A Semiparametric Approach to Simultaneous Covariance Estimation for Bivariate Sparse Longitudinal Data

    PubMed Central

    Das, Kiranmoy; Daniels, Michael J.

    2014-01-01

    Summary Estimation of the covariance structure for irregular sparse longitudinal data has been studied by many authors in recent years but typically using fully parametric specifications. In addition, when data are collected from several groups over time, it is known that assuming the same or completely different covariance matrices over groups can lead to loss of efficiency and/or bias. Nonparametric approaches have been proposed for estimating the covariance matrix for regular univariate longitudinal data by sharing information across the groups under study. For the irregular case, with longitudinal measurements that are bivariate or multivariate, modeling becomes more difficult. In this article, to model bivariate sparse longitudinal data from several groups, we propose a flexible covariance structure via a novel matrix stick-breaking process for the residual covariance structure and a Dirichlet process mixture of normals for the random effects. Simulation studies are performed to investigate the effectiveness of the proposed approach over more traditional approaches. We also analyze a subset of Framingham Heart Study data to examine how the blood pressure trajectories and covariance structures differ for the patients from different BMI groups (high, medium and low) at baseline. PMID:24400941

  9. Longitudinal design considerations to optimize power to detect variances and covariances among rates of change: Simulation results based on actual longitudinal studies

    PubMed Central

    Rast, Philippe; Hofer, Scott M.

    2014-01-01

    We investigated the power to detect variances and covariances in rates of change in the context of existing longitudinal studies using linear bivariate growth curve models. Power was estimated by means of Monte Carlo simulations. Our findings show that typical longitudinal study designs have substantial power to detect both variances and covariances among rates of change in a variety of cognitive, physical functioning, and mental health outcomes. We performed simulations to investigate the interplay among number and spacing of occasions, total duration of the study, effect size, and error variance on power and required sample size. The relation between growth rate reliability (GRR) and effect size to the sample size required to detect power ≥ .80 was non-linear, with rapidly decreasing sample sizes needed as GRR increases. The results presented here stand in contrast to previous simulation results and recommendations (Hertzog, Lindenberger, Ghisletta, & von Oertzen, 2006; Hertzog, von Oertzen, Ghisletta, & Lindenberger, 2008; von Oertzen, Ghisletta, & Lindenberger, 2010), which are limited due to confounds between study length and number of waves, error variance with GCR, and parameter values which are largely out of bounds of actual study values. Power to detect change is generally low in the early phases (i.e. first years) of longitudinal studies but can substantially increase if the design is optimized. We recommend additional assessments, including embedded intensive measurement designs, to improve power in the early phases of long-term longitudinal studies. PMID:24219544

  10. The limitations of opportunistic epidemiology, pseudopod epidemiology.

    PubMed

    Kuller, Lewis H

    2016-10-01

    Epidemiology has been remarkably successful in the past in identifying the important agents of disease, the impact of the environment, both physical and social, and interrelationship with host susceptibility (genomics). Many of the advances in improving the health of individuals and populations have been the result of epidemiology studies that have identified the specific "agents" of disease and application of public health and preventive medicine. In recent years, large longitudinal studies have dominated epidemiology research, especially long incubation period chronic diseases. The initial hypotheses in these studies have been expanded by vertical extension studies using newer technologies to measure independent variables, vertical pseudopods, and additional studies of other diseases, horizontal pseudopods, of the original longitudinal study. Host susceptibility, i.e. genomics, has also become a prominent component of these longitudinal studies. The critical question addressed in this paper is whether these "pseudopod" epidemiology approaches have enhanced public health or generated a large number of studies of little impact.

  11. A mechanical analysis of conduit arteries accounting for longitudinal residual strains.

    PubMed

    Wang, Ruoya; Gleason, Rudolph L

    2010-04-01

    Identification of an appropriate stress-free reference configuration is critically important in providing a reasonable prediction of the intramural stress distribution when performing biomechanical analyses on arteries. The stress-free state is commonly approximated as a radially cut ring that typically opens into a nearly circular sector, relieving much of the circumferential residual strains that exist in the traction-free configuration. An opening angle is often used to characterize this sector. In this study, we first present experimental results showing significant residual deformations in the longitudinal direction of two commonly studied arteries in the pig: the common carotid artery and the left anterior descending coronary artery. We concluded that a radially cut ring cannot completely describe the stress-free state of the arteries. Instead, we propose the use of a longitudinal opening angle, in conjunction with the traditional circumferential opening angle, to experimentally quantify the stress-free state of an artery. Secondly, we propose a new kinematic model to account for the addition of longitudinal residual strains through employing the longitudinal opening angle and performed a stress analysis. We found that with the inclusion of longitudinal residual strains in the stress analysis, the predicted circumferential stress gradient was decreased by 3-fold and the predicted longitudinal stress gradient was increased by 5.7-fold. Thus, inclusion of longitudinal residual strains has a significant effect on the predicted stress distribution in arteries.

  12. A varying-coefficient method for analyzing longitudinal clinical trials data with nonignorable dropout

    PubMed Central

    Forster, Jeri E.; MaWhinney, Samantha; Ball, Erika L.; Fairclough, Diane

    2011-01-01

    Dropout is common in longitudinal clinical trials and when the probability of dropout depends on unobserved outcomes even after conditioning on available data, it is considered missing not at random and therefore nonignorable. To address this problem, mixture models can be used to account for the relationship between a longitudinal outcome and dropout. We propose a Natural Spline Varying-coefficient mixture model (NSV), which is a straightforward extension of the parametric Conditional Linear Model (CLM). We assume that the outcome follows a varying-coefficient model conditional on a continuous dropout distribution. Natural cubic B-splines are used to allow the regression coefficients to semiparametrically depend on dropout and inference is therefore more robust. Additionally, this method is computationally stable and relatively simple to implement. We conduct simulation studies to evaluate performance and compare methodologies in settings where the longitudinal trajectories are linear and dropout time is observed for all individuals. Performance is assessed under conditions where model assumptions are both met and violated. In addition, we compare the NSV to the CLM and a standard random-effects model using an HIV/AIDS clinical trial with probable nonignorable dropout. The simulation studies suggest that the NSV is an improvement over the CLM when dropout has a nonlinear dependence on the outcome. PMID:22101223

  13. Exposure to peer delinquency as a mediator between self-report pubertal timing and delinquency: A longitudinal study of mediation

    PubMed Central

    Negriff, Sonya; Ji, Juye; Trickett, Penelope K.

    2013-01-01

    This study examined exposure to peer delinquency as a mediator between pubertal timing and self-reported delinquency longitudinally and whether this mediational model was moderated by either gender or maltreatment experience. Data were obtained from Time 1, 2, and 3 of a longitudinal study of maltreatment and development. At Time 1 the sample comprised 454 children aged 9–13 years. Analyses via structural equation modeling supported full mediation. Gender did not moderate this mediational relationship, but maltreatment experience did. The results show that early maturing males and females are both at risk for being exposed to peers that may draw them into delinquent behavior. Additionally, the mechanism linking early pubertal timing to delinquency differs depending on maltreatment experience. PMID:21262055

  14. Cross-sectional and longitudinal comparisons of metabolic profiles between vegetarian and non-vegetarian subjects: a matched cohort study.

    PubMed

    Chiu, Yen-Feng; Hsu, Chih-Cheng; Chiu, Tina H T; Lee, Chun-Yi; Liu, Ting-Ting; Tsao, Chwen Keng; Chuang, Su-Chun; Hsiung, Chao A

    2015-10-28

    Several previous cross-sectional studies have shown that vegetarians have a better metabolic profile than non-vegetarians, suggesting that a vegetarian dietary pattern may help prevent chronic degenerative diseases. However, longitudinal studies on the impact of vegetarian diets on metabolic traits are scarce. We studied how several sub-types of vegetarian diets affect metabolic traits, including waist circumference, BMI, systolic blood pressure (SBP), diastolic blood pressure, fasting blood glucose, total cholesterol (TC), HDL, LDL, TAG and TC:HDL ratio, through both cross-sectional and longitudinal study designs. The study used the MJ Health Screening database, with data collected from 1994 to 2008 in Taiwan, which included 4415 lacto-ovo-vegetarians, 1855 lacto-vegetarians and 1913 vegans; each vegetarian was matched with five non-vegetarians based on age, sex and study site. In the longitudinal follow-up, each additional year of vegan diet lowered the risk of obesity by 7 % (95 % CI 0·88, 0·99), whereas each additional year of lacto-vegetarian diet lowered the risk of elevated SBP by 8 % (95 % CI 0·85, 0·99) and elevated glucose by 7 % (95 % CI 0·87, 0·99), and each additional year of ovo-lacto-vegetarian diet increased abnormal HDL by 7 % (95 % CI 1·03, 1·12), compared with non-vegetarians. In the cross-sectional comparisons, all sub-types of vegetarians had lower likelihoods of abnormalities compared with non-vegetarians on all metabolic traits (P<0·001 for all comparisons), except for HDL and TAG. The better metabolic profile in vegetarians is partially attributable to lower BMI. With proper management of TAG and HDL, along with caution about the intake of refined carbohydrates and fructose, a plant-based diet may benefit all aspects of the metabolic profile.

  15. [Information management in multicenter studies: the Brazilian longitudinal study for adult health].

    PubMed

    Duncan, Bruce Bartholow; Vigo, Álvaro; Hernandez, Émerson; Luft, Vivian Cristine; Ahlert, Hubert; Bergmann, Kaiser; Mota, Eduardo

    2013-06-01

    Information management in large multicenter studies requires a specialized approach. The Estudo Longitudinal da Saúde do Adulto (ELSA-Brasil - Brazilian Longitudinal Study for Adult Health) has created a Datacenter to enter and manage its data system. The aim of this paper is to describe the steps involved, including the information entry, transmission and management methods. A web system was developed in order to allow, in a safe and confidential way, online data entry, checking and editing, as well as the incorporation of data collected on paper. Additionally, a Picture Archiving and Communication System was implemented and customized for echocardiography and retinography. It stores the images received from the Investigation Centers and makes them available at the Reading Centers. Finally, data extraction and cleaning processes were developed to create databases in formats that enable analyses in multiple statistical packages.

  16. Longitudinal assessment of treatment effects on pulmonary ventilation using 1H/3He MRI multivariate templates

    NASA Astrophysics Data System (ADS)

    Tustison, Nicholas J.; Contrella, Benjamin; Altes, Talissa A.; Avants, Brian B.; de Lange, Eduard E.; Mugler, John P.

    2013-03-01

    The utitlity of pulmonary functional imaging techniques, such as hyperpolarized 3He MRI, has encouraged their inclusion in research studies for longitudinal assessment of disease progression and the study of treatment effects. We present methodology for performing voxelwise statistical analysis of ventilation maps derived from hyper­ polarized 3He MRI which incorporates multivariate template construction using simultaneous acquisition of IH and 3He images. Additional processing steps include intensity normalization, bias correction, 4-D longitudinal segmentation, and generation of expected ventilation maps prior to voxelwise regression analysis. Analysis is demonstrated on a cohort of eight individuals with diagnosed cystic fibrosis (CF) undergoing treatment imaged five times every two weeks with a prescribed treatment schedule.

  17. Facebook: an effective tool for participant retention in longitudinal research.

    PubMed

    Mychasiuk, R; Benzies, K

    2012-09-01

    Facebook is currently one of the world's most visited websites, and home to millions of users who access their accounts on a regular basis. Owing to the website's ease of accessibility and free service, demographic characteristics of users span all domains. As such, Facebook may be a valuable tool for locating and communicating with participants in longitudinal research studies. This article outlines the benefit gained in a longitudinal follow-up study, of an intervention programme for at-risk families, through the use of Facebook as a search engine. Using Facebook as a resource, we were able to locate 19 participants that were otherwise 'lost' to follow-up, decreasing attrition in our study by 16%. Additionally, analysis indicated that hard-to-reach participants located with Facebook differed significantly on measures of receptive language and self-esteem when compared to their easier-to-locate counterparts. These results suggest that Facebook is an effective means of improving participant retention in a longitudinal intervention study and may help improve study validity by reaching participants that contribute differing results. © 2011 Blackwell Publishing Ltd.

  18. Impact of Legislation on Post-School Transition Practice for Young People with Additional Support Needs in Scotland

    ERIC Educational Resources Information Center

    Richardson, Thomas D.; Jindal-Snape, Divya; Hannah, Elizabeth F. S.

    2017-01-01

    A longitudinal study was conducted to understand post-school transition practice for young people with additional support needs (ASN) before and after the implementation of key legislation, the Education (Additional Support for Learning) (Scotland) Act 2004, amended in 2009. Primary data were collected from one local authority in Scotland. Twelve…

  19. Predicting long-term absenteeism from work in construction industry: a longitudinal study.

    PubMed

    Hoonakker, Peter; van Duivenbooden, Cor

    2012-01-01

    In this study we examine whether the Work Ability Index (WAI) has additional value in predicting long-term absenteeism in construction industry. Results of the study show that the WAI has additional value in predicting absenteeism, but that the amount of explained variance is low. This is partly due to the definition of absenteeism in The Netherlands, where this study took place.

  20. Longitudinal Changes in Serum Glucose Levels are Associated with Metabolic Changes in Alzheimer's Disease Related Brain Regions.

    PubMed

    Burns, Christine M; Kaszniak, Alfred W; Chen, Kewei; Lee, Wendy; Bandy, Daniel J; Caselli, Richard J; Reiman, Eric M

    2018-01-01

    The association between longitudinal changes in serum glucose level and longitudinal changes in [18F] Fluorodeoxyglucose-PET (FDG PET) measurements of Alzheimer's disease (AD) risk are unknown. To investigate whether variation in serum glucose levels across time are associated with changes in FDG PET measurements of cerebral metabolic rate for glucose (rCMRgl) in brain regions preferentially affected by Alzheimer's disease (AD). Participants are a subset of a prospective cohort study investigating FDG PET, apolipoprotein E (APOE) ɛ4, and risk for AD which includes data from baseline, interim, and follow up visits over 4.4±1.0-years. An automated brain-mapping algorithm was utilized to characterize and compare associations between longitudinal changes in serum glucose levels and longitudinal changes in rCMRgl. This study included 80 adults aged 61.5±5 years, including 38 carriers and 42 non-carriers of the APOE ɛ4 allele. Longitudinal increases in serum glucose levels were associated with longitudinal CMRgl decline in the vicinity of parietotemporal, precuneus/posterior cingulate, and prefrontal brain regions preferentially affected by AD (p < 0.05, corrected for multiple comparisons). Findings remained significant when controlled for APOE ɛ4 status and baseline and advancing age. Additional studies are needed to clarify and confirm the relationship between longitudinal changes in peripheral glucose and FDG PET measurements of AD risk. Future findings will set the stage on the use of FDG PET in the evaluation of possible interventions that target risk factors for the development of AD.

  1. Longitudinal changes in health-related quality of life for chronic diseases: an example in hemophilia A.

    PubMed

    Poon, Jiat-Ling; Doctor, Jason N; Nichol, Michael B

    2014-08-01

    Patients with well-managed rare chronic diseases such as hemophilia maintain a stable health state and health-related quality of life (HrQoL) that may be affected by acute events. Longitudinal HrQoL assessments analyzed using multivariate multilevel (MVML) modelling can determine the impact of such events on individuals (within-person effect) and identify factors influencing within-population differences (between-person effect). To demonstrate the application of MVML modelling in a longitudinal study of HrQoL in hemophilia A. Using data on 136 adults and 125 children from a two-year observational cohort study of burden of illness in US hemophilia A patients, MVML modelling determined the effect of time-invariant (sociodemographic and clinical characteristics) and time-varying factors (bleeding frequency, emergency room visits, and missed work/school days) on within-person and between-person HrQoL changes. HrQoL was assessed using the SF-12 health survey (adults) and PedsQL inventory (children) at baseline, then every 6 months. In children, within-person (p < 0.0001) and between-person (p < 0.0001) psychosocial functioning was reduced by each additional bleed and missed day (within-person: p = 0.0089; between-person: p = 0.0060). Within-person physical functioning was reduced by each additional bleed (p < 0.0001), emergency room (ER) visit (p = 0.0284), and missed day (p = 0.0473). Between-persons, additional missed days (p < 0.0001) significantly decreased physical functioning. In adults, each additional missed day reduced SF-12 Health Survey mental (p = 0.0025) and physical (p = 0.0093) component summary scores. Each additional bleed also decreased physical component summary (PCS) significantly (p = 0.0093). This study demonstrated the applicability of MVML modelling in identifying time-invariant and time-varying factors influencing HrQoL in a rare chronic disease population. Small but significant within-person and between-person changes in HrQoL with each additional acute event experienced were identified, which if frequent, could have a large cumulative impact. The results suggest that MVML modelling may be applied to future studies of longitudinal change in HrQoL in other rare chronic disease populations.

  2. Determination of multidirectional myocardial deformations in cats with hypertrophic cardiomyopathy by using two-dimensional speckle-tracking echocardiography.

    PubMed

    Suzuki, Ryohei; Mochizuki, Yohei; Yoshimatsu, Hiroki; Teshima, Takahiro; Matsumoto, Hirotaka; Koyama, Hidekazu

    2017-12-01

    Objectives Hypertrophic cardiomyopathy, a primary disorder of the myocardium, is the most common cardiac disease in cats. However, determination of myocardial deformation with two-dimensional speckle-tracking echocardiography in cats with various stages of hypertrophic cardiomyopathy has not yet been reported. This study was designed to measure quantitatively multidirectional myocardial deformations of cats with hypertrophic cardiomyopathy. Methods Thirty-two client-owned cats with hypertrophic cardiomyopathy and 14 healthy cats serving as controls were enrolled and underwent assessment of myocardial deformation (peak systolic strain and strain rate) in the longitudinal, radial and circumferential directions. Results Longitudinal and radial deformations were reduced in cats with hypertrophic cardiomyopathy, despite normal systolic function determined by conventional echocardiography. Cats with severely symptomatic hypertrophic cardiomyopathy also had lower peak systolic circumferential strain, in addition to longitudinal and radial strain. Conclusions and relevance Longitudinal and radial deformation may be helpful in the diagnosis of hypertrophic cardiomyopathy. Additionally, the lower circumferential deformation in cats with severe hypertrophic cardiomyopathy may contribute to clinical findings of decompensation, and seems to be related to severe cardiac clinical signs. Indices of multidirectional myocardial deformations by two-dimensional speckle-tracking echocardiography may be useful markers and help to distinguish between cats with hypertrophic cardiomyopathy and healthy cats. Additionally, they may provide more detailed assessment of contractile function in cats with hypertrophic cardiomyopathy.

  3. Studies of thermal wave phenomena on the Jovian planets

    NASA Technical Reports Server (NTRS)

    Deming, Drake

    1991-01-01

    Ground-based and Voyager observations of Jupiter provided evidence that the tropospheric temperature shows global-scale longitudinal variations which are often wavelike in character. The investigation is presented which is directed toward obtaining additional ground-based data in IR spectral bands whose contribution functions are optimized for specific atmospheric regions, in order to confirm the previous results, and to identify the nature and physical significance of wavelike longitudinal temperature fluctuations on the Jovian planets.

  4. Detection of Early lung Cancer Among Military Personnel (DECAMP)

    DTIC Science & Technology

    2017-10-01

    addition of two new recruitment sites. We have recruited ~75% of the 500 total subjects in the indeterminate pulmonary nodule study (Protocol 1), and...60% of the 800 total subjects in the longitudinal screening study (Protocol 2). We have also added a junior faculty pulmonary physician and scientific...supplement infrastructure support within DECAMP and pursue additional biomarker studies . 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17

  5. Personality, work characteristics, and employee well-being: a longitudinal analysis of additive and moderating effects.

    PubMed

    Houkes, Inge; Janssen, Peter P M; de Jonge, Jan; Bakker, Arnold B

    2003-01-01

    This study tested the longitudinal influence of personality (measured by the characteristics growth need strength, negative affectivity [NA], and upward striving) on 3 psychological outcomes (intrinsic work motivation, emotional exhaustion, and turnover intention), using a pattern of specific relationships between work characteristics and these outcomes as a framework. The study hypotheses were tested in a multioccupational sample consisting of bank employees and teachers, using a 2-wave panel design with a 1-year time interval and structural equation modeling. NA had a cross-lagged direct and additive relationship with emotional exhaustion and also moderated the relationship between Time 1 workload and Time 2 emotional exhaustion. The authors concluded that NA may have multiple effects on emotional exhaustion that persist over time.

  6. Boosting structured additive quantile regression for longitudinal childhood obesity data.

    PubMed

    Fenske, Nora; Fahrmeir, Ludwig; Hothorn, Torsten; Rzehak, Peter; Höhle, Michael

    2013-07-25

    Childhood obesity and the investigation of its risk factors has become an important public health issue. Our work is based on and motivated by a German longitudinal study including 2,226 children with up to ten measurements on their body mass index (BMI) and risk factors from birth to the age of 10 years. We introduce boosting of structured additive quantile regression as a novel distribution-free approach for longitudinal quantile regression. The quantile-specific predictors of our model include conventional linear population effects, smooth nonlinear functional effects, varying-coefficient terms, and individual-specific effects, such as intercepts and slopes. Estimation is based on boosting, a computer intensive inference method for highly complex models. We propose a component-wise functional gradient descent boosting algorithm that allows for penalized estimation of the large variety of different effects, particularly leading to individual-specific effects shrunken toward zero. This concept allows us to flexibly estimate the nonlinear age curves of upper quantiles of the BMI distribution, both on population and on individual-specific level, adjusted for further risk factors and to detect age-varying effects of categorical risk factors. Our model approach can be regarded as the quantile regression analog of Gaussian additive mixed models (or structured additive mean regression models), and we compare both model classes with respect to our obesity data.

  7. The Influence of Social Conditions Across the Life Course on the Human Gut Microbiota: A Pilot Project With the Wisconsin Longitudinal Study.

    PubMed

    Herd, Pamela; Schaeffer, Nora Cate; DiLoreto, Kerryann; Jacques, Karen; Stevenson, John; Rey, Federico; Roan, Carol

    2017-12-15

    To test the feasibility of collecting and integrating data on the gut microbiome into one of the most comprehensive longitudinal studies of aging and health, the Wisconsin Longitudinal Study (WLS). The long-term goal of this integration is to clarify the contribution of social conditions in shaping the composition of the gut microbiota late in life. Research on the microbiome, which is considered to be of parallel importance to human health as the human genome, has been hindered by human studies with nonrandomly selected samples and with limited data on social conditions over the life course. No existing population-based longitudinal study had collected fecal specimens. Consequently, we created an in-person protocol to collect stool specimens from a subgroup of WLS participants. We collected 429 stool specimens, yielding a 74% response rate and one of the largest human samples to date. The addition of data on the gut microbiome to the WLS-and to other population based longitudinal studies of aging-is feasible, under the right conditions, and can generate innovative research on the relationship between social conditions and the gut microbiome. © The Author 2017. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  8. On the Development of Perfectionism: The Longitudinal Role of Academic Achievement and Academic Efficacy.

    PubMed

    Damian, Lavinia E; Stoeber, Joachim; Negru-Subtirica, Oana; Băban, Adriana

    2017-08-01

    Although perfectionism is a prominent personality disposition, only a few longitudinal studies have investigated how perfectionism develops. Theoretical models and qualitative studies have posited that academic success is a developmental antecedent of perfectionism. Yet, quantitative studies tend to interpret the cross-sectional relationships as academic success being an outcome of perfectionism. In light of these gaps in the literature, the present study was the first to investigate the longitudinal relationships between perfectionistic strivings, perfectionistic concerns, academic achievement, and academic efficacy by examining academic success as an antecedent of perfectionism. The study examined 487 adolescents (aged 12-19 years, 54% female) using a cross-lagged longitudinal design with three time points spaced 4-5 months apart. Results showed that academic achievement predicted relative increases in both perfectionistic strivings and perfectionistic concerns, even when including academic efficacy. In addition, academic efficacy predicted relative increases in perfectionistic strivings. This is the first study to show that academic achievement is a common factor in the development of perfectionistic strivings and perfectionistic concerns, whereas academic efficacy plays a role only in the development of perfectionistic strivings. Implications of the findings for the development of perfectionism are discussed. © 2016 Wiley Periodicals, Inc.

  9. STRUCTURAL AND CONNECTOMIC NEUROIMAGING FOR THE PERSONALIZED STUDY OF LONGITUDINAL ALTERATIONS IN CORTICAL SHAPE, THICKNESS AND CONNECTIVITY AFTER TRAUMATIC BRAIN INJURY

    PubMed Central

    Irimia, A.; Goh, S.-Y. M.; Torgerson, C. M.; Vespa, P. M.; Van Horn, J. D.

    2014-01-01

    The integration of longitudinal brain structure analysis with neurointensive care strategies continues to be a substantial difficulty facing the traumatic brain injury (TBI) research community. For patient-tailored case analysis, it remains challenging to establish how lesion profile modulates longitudinal changes in cortical structure and connectivity, as well as how these changes lead to behavioral, cognitive and neural dysfunction. Additionally, despite the clinical potential of morphometric and connectomic studies, few analytic tools are available for their study in TBI. Here we review the state of the art in structural and connectomic neuroimaging for the study of TBI and illustrate a set of recently-developed, patient-tailored approaches for the study of TBI-related brain atrophy and alterations in morphometry as well as inter-regional connectivity. The ability of such techniques to quantify how injury modulates longitudinal changes in cortical shape, structure and circuitry is highlighted. Quantitative approaches such as these can be used to assess and monitor the clinical condition and evolution of TBI victims, and can have substantial translational impact, especially when used in conjunction with measures of neuropsychological function. PMID:24844173

  10. Does informal caregiving affect self-esteem? Results from a population-based study of individuals aged 40 and over in Germany from 2002 to 2014.

    PubMed

    Hajek, André; König, Hans-Helmut

    2017-11-29

    While it is known that informal caregiving is associated with care-derived self-esteem cross-sectionally, little is known about the impact of informal caregiving on general self-esteem longitudinally. Thus, we aimed at examining whether informal caregiving affects general self-esteem using a longitudinal approach. Data were gathered from a population-based sample of community-dwelling individuals aged 40 and over in Germany from 2002 to 2014 (n = 21 271). General self-esteem was quantified using the Rosenberg scale. Individuals were asked whether they provide informal care regularly. Fixed effects regressions showed no significant effect of informal caregiving on general self-esteem longitudinally. General self-esteem decreased with increasing morbidity, increasing age, decreasing social ties, whereas it was not associated with changes in employment status, marital status and body mass index. Additional models showed that decreases in self-esteem were associated with decreases in functional health and increases in depressive symptoms. Our longitudinal study emphasises that the occurrence of informal caregiving did not affect general self-esteem longitudinally. Further research is needed in other cultural settings using panel data methods. © 2017 Nordic College of Caring Science.

  11. Longitudinal and transverse right ventricular function in pulmonary hypertension: cardiovascular magnetic resonance imaging study from the ASPIRE registry

    PubMed Central

    Rajaram, Smitha; Capener, Dave; Elliot, Charlie; Condliffe, Robin; Wild, Jim M.; Kiely, David G.

    2015-01-01

    Abstract Right ventricular (RV) function is a strong predictor of outcome in cardiovascular diseases. Two components of RV function, longitudinal and transverse motion, have been investigated in pulmonary hypertension (PH). However, their individual clinical significance remains uncertain. The aim of this study was to determine the factors associated with transverse and longitudinal RV motion in patients with PH. In 149 treatment-naive patients with PH and 16 patients with suspected PH found to have mean pulmonary arterial pressure of <20 mmHg, cardiovascular magnetic resonance imaging was performed within 24 hours of right heart catheterization. In patients with PH, fractional longitudinal motion (fractional tricuspid annulus to apex distance [f-TAAD]) was significantly greater than fractional transverse motion (fractional septum to free wall distance [f-SFD]; P = 0.002). In patients without PH, no significant difference between f-SFD and f-TAAD was identified (P = 0.442). Longitudinal RV motion was singularly associated with RV ejection fraction independent of age, invasive hemodynamics, and cardiac magnetic resonance measurements (P = 0.024). In contrast, transverse RV motion was independently associated with left ventricular eccentricity (P = 0.036) in addition to RV ejection fraction (P = 0.014). In conclusion, RV motion is significantly greater in the longitudinal direction in patients with PH, whereas patients without PH have equal contributions of transverse and longitudinal motion. Longitudinal RV motion is primarily associated with global RV pump function in PH. Transverse RV motion not only reflects global pump function but is independently influenced by ventricular interaction in patients with PH. PMID:26401257

  12. Longitudinal and transverse right ventricular function in pulmonary hypertension: cardiovascular magnetic resonance imaging study from the ASPIRE registry.

    PubMed

    Swift, Andrew J; Rajaram, Smitha; Capener, Dave; Elliot, Charlie; Condliffe, Robin; Wild, Jim M; Kiely, David G

    2015-09-01

    Right ventricular (RV) function is a strong predictor of outcome in cardiovascular diseases. Two components of RV function, longitudinal and transverse motion, have been investigated in pulmonary hypertension (PH). However, their individual clinical significance remains uncertain. The aim of this study was to determine the factors associated with transverse and longitudinal RV motion in patients with PH. In 149 treatment-naive patients with PH and 16 patients with suspected PH found to have mean pulmonary arterial pressure of <20 mmHg, cardiovascular magnetic resonance imaging was performed within 24 hours of right heart catheterization. In patients with PH, fractional longitudinal motion (fractional tricuspid annulus to apex distance [f-TAAD]) was significantly greater than fractional transverse motion (fractional septum to free wall distance [f-SFD]; P = 0.002). In patients without PH, no significant difference between f-SFD and f-TAAD was identified (P = 0.442). Longitudinal RV motion was singularly associated with RV ejection fraction independent of age, invasive hemodynamics, and cardiac magnetic resonance measurements (P = 0.024). In contrast, transverse RV motion was independently associated with left ventricular eccentricity (P = 0.036) in addition to RV ejection fraction (P = 0.014). In conclusion, RV motion is significantly greater in the longitudinal direction in patients with PH, whereas patients without PH have equal contributions of transverse and longitudinal motion. Longitudinal RV motion is primarily associated with global RV pump function in PH. Transverse RV motion not only reflects global pump function but is independently influenced by ventricular interaction in patients with PH.

  13. A Longitudinal Item Response Theory Model to Characterize Cognition Over Time in Elderly Subjects

    PubMed Central

    Bornkamp, Björn; Krahnke, Tillmann; Mielke, Johanna; Monsch, Andreas; Quarg, Peter

    2017-01-01

    For drug development in neurodegenerative diseases such as Alzheimer's disease, it is important to understand which cognitive domains carry the most information on the earliest signs of cognitive decline, and which subject characteristics are associated with a faster decline. A longitudinal Item Response Theory (IRT) model was developed for the Basel Study on the Elderly, in which the Consortium to Establish a Registry for Alzheimer's Disease – Neuropsychological Assessment Battery (with additions) and the California Verbal Learning Test were measured on 1,750 elderly subjects for up to 13.9 years. The model jointly captured the multifaceted nature of cognition and its longitudinal trajectory. The word list learning and delayed recall tasks carried the most information. Greater age at baseline, fewer years of education, and positive APOEɛ4 carrier status were associated with a faster cognitive decline. Longitudinal IRT modeling is a powerful approach for progressive diseases with multifaceted endpoints. PMID:28643388

  14. Self-esteem in pure bullies and bully/victims: a longitudinal analysis.

    PubMed

    Pollastri, Alisha R; Cardemil, Esteban V; O'Donnell, Ellen H

    2010-08-01

    Past research on the self-esteem of bullies has produced equivocal results. Recent studies have suggested that the inconsistent findings may be due, in part, to the failure to account for bully/victims: those children who both bully and are victims of bullying. In this longitudinal study, we examined the distinctions among pure bullies, pure victims, bully/victims, and noninvolved children in a sample of 307 middle school students. Analyses of cross-sectional and longitudinal results supported the importance of distinguishing between pure bullies and bully/victims. In addition, results revealed some interesting sex differences: girls in the pure bully and bully/victim groups reported significant increases in self-esteem over time, with girls in the pure bully group reporting the greatest increase, whereas boys in these groups reported no significant changes in self-esteem over time.

  15. Psychosocial work characteristics and sleep quality: a systematic review of longitudinal and intervention research.

    PubMed

    Van Laethem, Michelle; Beckers, Debby G J; Kompier, Michiel A J; Dijksterhuis, Ap; Geurts, Sabine A E

    2013-11-01

    The objective of this study was to review longitudinal and intervention studies examining the association between psychosocial work characteristics (eg, job demands, job control, and social support) and sleep quality. Our main research aims were to examine whether (i) psychosocial work characteristics are a predictor of sleep quality, and (ii) sleep quality, in turn, is a predictor of psychosocial work characteristics. A systematic literature search resulted in 20 relevant papers, of which 16 were longitudinal studies and 3 were intervention studies (1 study was discussed in separate papers). To quantify results, we assessed the strength of evidence of all examined associations and subsequently evaluated the studies' research quality based on predefined quality criteria. One intervention and three longitudinal studies studies were categorized as being of high-quality. In longitudinal studies, we found consistent and strong evidence for a negative relation between job demands and sleep quality as well as evidence for a positive relation between job control and sleep quality. Other psychosocial work characteristics were examined in an insufficient number of (high-quality) studies. Moreover, both intervention studies as well as studies investigating reversed and reciprocal relations are rare, which further limits the possibility of drawing conclusions on causality. Based on the current literature, it can be concluded that high job demands and low job control are predictors of poor sleep quality. More high-quality research is needed to examine the possible causal relationship between these and other psychosocial work characteristics with sleep quality, in addition to research focusing on reversed and reciprocal relations.

  16. A Longitudinal Field Study Comparing a Multiplicative and an Additive Model of Motivation and Ability. Technical Report No. 11.

    ERIC Educational Resources Information Center

    Barrett, Gerald V.; And Others

    The relative contribution of motivation to ability measures in predicting performance criteria of sales personnel from successive fiscal periods was investigated. In this context, the merits of a multiplicative and additive combination of motivation and ability measures were examined. The relationship between satisfaction and motivation and…

  17. Browsing, Posting, and Liking on Instagram: The Reciprocal Relationships Between Different Types of Instagram Use and Adolescents' Depressed Mood.

    PubMed

    Frison, Eline; Eggermont, Steven

    2017-10-01

    Although studies have shown that Instagram use and young adults' mental health are cross-sectionally associated, longitudinal evidence is lacking. In addition, no study thus far examined this association, or the reverse, among adolescents. To address these gaps, we set up a longitudinal panel study among 12- to 19-year-old Flemish adolescents to investigate the reciprocal relationships between different types of Instagram use and depressed mood. Self-report data from 671 adolescent Instagram users (61% girls; M Age  = 14.96; SD = 1.29) were used to examine our research question and test our hypotheses. Structural equation modeling showed that Instagram browsing at Time 1 was related to increases in adolescents' depressed mood at Time 2. In addition, adolescents' depressed mood at Time 1 was related to increases in Instagram posting at Time 2. These relationships were similar among boys and girls. Potential explanations for the study findings and suggestions for future research are discussed.

  18. Longitudinal interrelationships between frequent geographic relocation and personality development: results from the Amsterdam Growth and Health Longitudinal Study.

    PubMed

    Lin, Kuan-Chia; Twisk, Jos W R; Rong, Jiin-Ru

    2011-04-01

    This study is part of the Amsterdam Growth and Health Longitudinal Study, which was undertaken to assess the long-term interrelationships between cumulative frequency of geographic relocation (CFGR) and the development of personality characteristics (i.e., Inadequacy, Rigidity, Social Inadequacy, Dominance, Self-sufficiency, Self-esteem, and Hostility). We found that participants who had more mobility experiences had lower consistency in their personality characteristics (the exception being Rigidity). Residential mobility from different life stages was positively associated with the continuity and change of Inadequacy and Dominance. In addition, young adults with higher Rigidity personality experienced fewer geographic moves during the transition from young adulthood to mid-life. Our study provides evidence that CFGR in different life stages may be associated with the development of personality characteristics from young adulthood to mid-life in different ways. Increased awareness of the potential interrelationships between frequent geographic relocation and personality development may have positive consequences for adult psychological health. © 2011 American Orthopsychiatric Association.

  19. MODELING LEFT-TRUNCATED AND RIGHT-CENSORED SURVIVAL DATA WITH LONGITUDINAL COVARIATES

    PubMed Central

    Su, Yu-Ru; Wang, Jane-Ling

    2018-01-01

    There is a surge in medical follow-up studies that include longitudinal covariates in the modeling of survival data. So far, the focus has been largely on right censored survival data. We consider survival data that are subject to both left truncation and right censoring. Left truncation is well known to produce biased sample. The sampling bias issue has been resolved in the literature for the case which involves baseline or time-varying covariates that are observable. The problem remains open however for the important case where longitudinal covariates are present in survival models. A joint likelihood approach has been shown in the literature to provide an effective way to overcome those difficulties for right censored data, but this approach faces substantial additional challenges in the presence of left truncation. Here we thus propose an alternative likelihood to overcome these difficulties and show that the regression coefficient in the survival component can be estimated unbiasedly and efficiently. Issues about the bias for the longitudinal component are discussed. The new approach is illustrated numerically through simulations and data from a multi-center AIDS cohort study. PMID:29479122

  20. Longitudinal dependence of the seasonal variations of the topside ionospheric and plasmaspheric electron content: observations and model results

    NASA Astrophysics Data System (ADS)

    Zhang, Man-Lian; Liu, Libo; Ning, Baiqi; Wan, Weixing

    2016-07-01

    Radio signals transmitted from GPS satellite going through the ionization zone above the Earth will be refracted by the ionized components in the ionosphere and the plasmasphere, which would produce additional transfer delay and generate extra errors in satellite navigation and positioning, etc. These errors have strong relation with the total electron content (TEC) along the signal's travelling path. Therefore TEC is one of the most important parameters required by many users for different modern usage purposes. The topside ionospheric and plasmaspheric electron content makes a large contribution to TEC. In the present study, data for the year 2008 of the topside ionospheric and plasmaspheric electron content (PEC) between the height of 800-20200km above the Earth derived from the upward-looking TEC measurements of the precise orbit determination antenna on board the COSMIC low Earth orbit (LEO) satellites to the GPS signals are used to study the longitudinal dependence of the seasonal variations of PEC. A comparison study of the observed PEC with the IZMIRAN_Plas model results is also made. Our study showed that PEC shows different seasonal variations at different longitudinal sectors: for the 240°E-60°E longitudinal sector, PEC shows a strong annual variation with lowest value in the June solstice and highest value in the December solstice months; In contrast, very weak seasonal variations are observed for PEC at 60°E-240°E longitudinal sector; Comparison study showed that this longitudinal dependence feature of the observed PEC's seasonal variation is not well captured by the IZMIRAN_Plas model result. Acknowledgments This research was supported by the National Natural Science Foundation of China (NSFC No. 41274163)

  1. Change in Psychosocial Health Status Over 5 Years in Relation to Adults' Hearing Ability in Noise.

    PubMed

    Stam, Mariska; Smit, Jan H; Twisk, Jos W R; Lemke, Ulrike; Smits, Cas; Festen, Joost M; Kramer, Sophia E

    The aim of this study was to establish the longitudinal relationship between hearing ability in noise and psychosocial health outcomes (i.e., loneliness, anxiety, depression, distress, and somatization) in adults aged 18 to 70 years. An additional objective was to determine whether a change in hearing ability in noise over a period of 5 years was associated with a change in psychosocial functioning. Subgroup effects for a range of factors were investigated. Longitudinal data of the web-based Netherlands Longitudinal Study on Hearing (NL-SH) (N = 508) were analyzed. The ability to recognize speech in noise (i.e., the speech-reception-threshold [SRTn]) was measured with an online digit triplet test at baseline and at 5-year follow-up. Psychosocial health status was assessed by online questionnaires. Multiple linear regression analyses and longitudinal statistical analyses (i.e., generalized estimating equations) were performed. Poorer SRTn was associated longitudinally with more feelings of emotional and social loneliness. For participants with a high educational level, the longitudinal association between SRTn and social loneliness was significant. Changes in hearing ability and loneliness appeared significantly associated only for specific subgroups: those with stable pattern of hearing aid nonuse (increased emotional and social loneliness), who entered matrimony (increased social loneliness), and low educational level (less emotional loneliness). No significant longitudinal associations were found between hearing ability and anxiety, depression, distress, or somatization. Hearing ability in noise was longitudinally associated with loneliness. Decline in hearing ability in noise was related to increase in loneliness for specific subgroups of participants. One of these subgroups included participants whose hearing deteriorated over 5 years, but who continued to report nonuse of hearing aids. This is an important and alarming finding that needs further investigation.

  2. Effect of Wave Reflection and Arterial Stiffness on the Risk of Development of Hypertension in Japanese Men.

    PubMed

    Tomiyama, Hirofumi; Komatsu, Shunsuke; Shiina, Kazuki; Matsumoto, Chisa; Kimura, Kazutaka; Fujii, Masatsune; Takahashi, Lisa; Chikamori, Taishiro; Yamashina, Akira

    2018-05-08

    We conducted analyses of repeated-measures data to examine whether pressure wave reflection acts additively or synergistically with arterial stiffness in the pathogenesis of hypertension. In 3172 middle-aged (42±9 years) healthy Japanese men without hypertension at the study baseline, systolic and diastolic blood pressures, brachial-ankle pulse wave velocity, and radial augmentation index were measured annually during a 9-year study period. Of these, 474 participants (15%) developed hypertension by the end of the study period. Binary logistic regression analysis demonstrated significant individual odds ratios for both baseline brachial-ankle pulse wave velocity and radial augmentation index for the development of hypertension. The rate of onset of hypertension during the study period was highest in the participant group with high values for both brachial-ankle pulse wave velocity and radial augmentation index at study baseline (262 of 965 participants: 27%). The generalized estimating equation analysis revealed that both radial augmentation index (estimate=0.06, SE=0.03, P =0.05) and brachial-ankle pulse wave velocity (estimate=0.07×10 -1 , SE=0.02×10 -1 , P <0.01) showed significant longitudinal association with new onset of hypertension, with no significant interaction. In Japanese men, abnormal wave reflection and increased arterial stiffness may be additively associated with the risk of new onset of hypertension. Abnormal wave reflection and elevated central blood pressure may be longitudinally associated with increase in arterial stiffness, and this longitudinal association may be a mechanism underlying the additive effect of these 2 variables on the risk of new onset of hypertension. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  3. Longitudinal maturation of auditory cortical function during adolescence.

    PubMed

    Fitzroy, Ahren B; Krizman, Jennifer; Tierney, Adam; Agouridou, Manto; Kraus, Nina

    2015-01-01

    Cross-sectional studies have demonstrated that the cortical auditory evoked potential (CAEP) changes substantially in amplitude and latency from childhood to adulthood, suggesting that these aspects of the CAEP continue to mature through adolescence. However, no study to date has longitudinally followed maturation of these CAEP measures through this developmental period. Additionally, no study has examined the trial-to-trial variability of the CAEP during adolescence. Therefore, we longitudinally tracked changes in the latency, amplitude, and variability of the P1, N1, P2, and N2 components of the CAEP in 68 adolescents from age 14 years to age 17 years. Latency decreased for N1 and N2, and did not change for P1 or P2. Amplitude decreased for P1 and N2, increased for N1, and did not change for P2. Variability decreased with age for all CAEP components. These findings provide longitudinal support for the view that the human auditory system continues to mature through adolescence. Continued auditory system maturation through adolescence suggests that CAEP neural generators remain plastic during this age range and potentially amenable to experience-based enhancement or deprivation.

  4. A longitudinal analysis of burnout in middle and high school Korean teachers.

    PubMed

    Park, Yang Min; Lee, Sang Min

    2013-12-01

    This study examines longitudinal relationships among three burnout dimensions in middle and high school teachers. For this study, 419 middle and high school teachers participated in a panel survey, which was conducted in three waves. Using Amos 7.0, we performed autoregressive cross-lagged modeling to obtain a complete picture of the longitudinal relationships among the three factors of the Maslach Burnout Inventory-Educator Survey. Results indicated that the paths from emotional exhaustion at Time1 and Time2 to depersonalization at Time2 and Time3 were statistically significant. In addition, the paths from personal accomplishment at Time1 and Time2 to depersonalization at Time2 and Time3 were also statistically significant. Empirically identifying the process by which burnout occurs could help practitioners and policy makers to design burnout prevention strategies. Copyright © 2012 John Wiley & Sons, Ltd.

  5. Does Negative Interaction in the Church Increase Psychological Distress? Longitudinal Findings from the Presbyterian Panel Survey*

    PubMed Central

    Ellison, Christopher G.; Zhang, Wei; Krause, Neal; Marcum, John P.

    2009-01-01

    This study examines the effects of negative interaction in church on psychological distress. After outlining a series of theoretical arguments linking negative interaction with health and well-being, relevant hypotheses are tested using longitudinal data from two surveys of the 1997–1999 Presbyterian Panel, a nationwide panel of members and elders (lay leaders) in congregations of the Presbyterian Church (USA). Findings confirm that negative interaction appears to foster or exacerbate distress over the study period. In addition, specific dimensions of social negativity have distinctive effects; the impact of criticisms on distress surface only in cross-sectional models, while the effects of excessive demands emerge only in the longitudinal models. No subgroup variations in these effects are detected. Implications of these findings are discussed with regard to (a) research on religion and health and (b) congregational life, and a number of promising directions for future research are elaborated. PMID:20694051

  6. A longitudinal study of the effects of dual-earner couples' utilization of family-friendly workplace supports on work and family outcomes.

    PubMed

    Hammer, Leslie B; Neal, Margaret B; Newsom, Jason T; Brockwood, Krista J; Colton, Cari L

    2005-07-01

    Little research exists on the effects of the utilization of workplace supports on work-family conflict and job satisfaction. With family systems theory as a framework, 2 waves of national survey data were collected from 234 couples (N = 468) caring for children and for aging parents. Data were analyzed with structural equation modeling techniques. Longitudinal results indicate that individuals' use of workplace supports was related to work-family conflict in the direction opposite to expectations and was related to job satisfaction in the direction consistent with expectations. Differential effects for wives versus husbands were found. In addition, couples' use of workplace supports was only minimally related to wives' outcomes. Results are discussed in terms of gender differences, family systems theory, and methodological and measurement issues related to the longitudinal study of utilization of workplace supports. Copyright 2005 APA, all rights reserved.

  7. The association of suicide and bullying in childhood to young adulthood: a review of cross-sectional and longitudinal research findings.

    PubMed

    Brunstein Klomek, Anat; Sourander, Andre; Gould, Madelyn

    2010-05-01

    To review the research addressing the association of suicide and bullying, from childhood to young adulthood, including cross-sectional and longitudinal research findings. Relevant publications were identified via electronic searches of PsycNet and MEDLINE without date specification, in addition to perusing the reference lists of relevant articles. Cross-sectional findings indicate that there is an increased risk of suicidal ideation and (or) suicide attempts associated with bullying behaviour and cyberbullying. The few longitudinal findings available indicate that bullying and peer victimization lead to suicidality but that this association varies by sex. Discrepancies between the studies available may be due to differences in the studies' participants and methods. Bullying and peer victimization constitute more than correlates of suicidality. Future research with long-term follow-up should continue to identify specific causal paths between bullying and suicide.

  8. Observing Parent Behavior: Reconciling Theoretical Concepts with Empirical Reality.

    ERIC Educational Resources Information Center

    Ge, Xiaojia

    Using data from the Iowa Youth and Families Project, this longitudinal study investigated the predictive validity of different dimensions of observed parent behavior on adolescent externalizing (aggression, hostility) and internalizing (depression, anxiety) problems over a 2-year period. In addition, the study examined how observer ratings…

  9. Key trends in environmental advertising across 30 years in National Geographic magazine.

    PubMed

    Ahern, Lee; Bortree, Denise Sevick; Smith, Alexandra Nutter

    2013-05-01

    This longitudinal retrospective case study describes the sponsors, ad types, frames and message factors in green advertising over three decades in National Geographic magazine, the bellwether nature publication in the USA. In addition to providing a clearer picture of the extent and nature of environmental strategic messaging over three decades, results provide empirical support for theoretical relationships between the level of green advertising and economic indicators. After providing historical and theoretical context, detailed results are presented for both overall and longitudinal analysis. Limitations and implications for future research are discussed.

  10. Model Predictive Flight Control System with Full State Observer using H∞ Method

    NASA Astrophysics Data System (ADS)

    Sanwale, Jitu; Singh, Dhan Jeet

    2018-03-01

    This paper presents the application of the model predictive approach to design a flight control system (FCS) for longitudinal dynamics of a fixed wing aircraft. Longitudinal dynamics is derived for a conventional aircraft. Open loop aircraft response analysis is carried out. Simulation studies are illustrated to prove the efficacy of the proposed model predictive controller using H ∞ state observer. The estimation criterion used in the {H}_{∞} observer design is to minimize the worst possible effects of the modelling errors and additive noise on the parameter estimation.

  11. Poorer Visual Acuity Is Associated with Declines in Cognitive Performance Across Multiple Cognitive Domains: The Maine-Syracuse Longitudinal Study.

    PubMed

    Dearborn, Peter J; Elias, Merrill F; Sullivan, Kevin J; Sullivan, Cara E; Robbins, Michael A

    2018-06-21

    Prior studies have found associations between visual acuity (VA) and cognitive function. However, these studies used a limited range of cognitive measures and did not control for cardiovascular disease risk factors (CVD-RFs) and baseline function. The primary objective of this study was to analyze the associations of VA and cognitive performance using a thorough neuropsychological test battery. This study used community-dwelling sample data across the sixth (2001-2006) and seventh (2006-2010) waves of the Maine-Syracuse Longitudinal Study (n=655). Wave 6 VA as measured by the Snellen Eye Test was the primary predictor of wave 6 and wave 7 Global cognitive performance, Visual-Spatial Organization and Memory, Verbal Episodic Memory, Working Memory, Scanning and Tracking, and Executive Function. Additionally, VA was used to predict longitudinal changes in wave 7 cognitive performance (wave 6 performance adjusted). We analyzed these relationships with multiple linear and logistic regression models adjusted for age, sex, education, ethnicity, depressive symptoms, physical function deficits in addition to CVD-RFs, chronic kidney disease, homocysteine, continuous systolic blood pressure, and hypertension status. Adjusted for demographic covariates and CVD-RFs, poorer VA was associated with concurrent and approximate 5-year declines in Global cognitive function, Visual-Spatial Organization and Memory, and Verbal Episodic Memory. VA may be used in combination with other screening measures to determine risk for cognitive decline. (JINS, 2018, 24, 1-9).

  12. The Relationship of Repeated Technical Assistance Support Visits to the Delivery of Positive Health, Dignity, and Prevention (PHDP) Messages by Healthcare Providers in Mozambique: A Longitudinal Multilevel Analysis.

    PubMed

    Gutin, Sarah A; Amico, K Rivet; Hunguana, Elsa; Munguambe, António Orlando; Rose, Carol Dawson

    Positive health, dignity, and prevention (PHDP) is Mozambique's strategy to engage clinicians in the delivery of prevention messages to their HIV-positive clients. This national implementation strategy uses provider trainings on offering key messages and focuses on intervening on 9 evidence-based risk reduction areas. We investigated the impact of longitudinal technical assistance (TA) as an addition to this basic training. We followed 153 healthcare providers in 5 Mozambican provinces over 6 months to evaluate the impact of on-site, observation-based TA on PHDP implementation. Longitudinal multilevel models were estimated to model change in PHDP message delivery over time among individual providers. With each additional TA visit, providers delivered about 1 additional PHDP message ( P < .001); clinicians and nonclinicians started at about the same baseline level, but clinicians improved more quickly ( P = .004). Message delivery varied by practice sector; maternal and child health sectors outperformed other sectors. Longitudinal TA helped reach the programmatic goals of the PHDP program in Mozambique.

  13. Polarizations of gravitational waves in Horndeski theory

    NASA Astrophysics Data System (ADS)

    Hou, Shaoqi; Gong, Yungui; Liu, Yunqi

    2018-05-01

    We analyze the polarization content of gravitational waves in Horndeski theory. Besides the familiar plus and cross polarizations in Einstein's General Relativity, there is one more polarization state which is the mixture of the transverse breathing and longitudinal polarizations. The additional mode is excited by the massive scalar field. In the massless limit, the longitudinal polarization disappears, while the breathing one persists. The upper bound on the graviton mass severely constrains the amplitude of the longitudinal polarization, which makes its detection highly unlikely by the ground-based or space-borne interferometers in the near future. However, pulsar timing arrays might be able to detect the polarization excited by the massive scalar field. Since additional polarization states appear in alternative theories of gravity, the measurement of the polarizations of gravitational waves can be used to probe the nature of gravity. In addition to the plus and cross states, the detection of the breathing polarization means that gravitation is mediated by massless spin 2 and spin 0 fields, and the detection of both the breathing and longitudinal states means that gravitation is propagated by the massless spin 2 and massive spin 0 fields.

  14. Use of Longitudinal Data in Genetic Studies in the Genome-wide Association Studies Era: Summary of Group 14

    PubMed Central

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

    2010-01-01

    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 multi-factorial 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

  15. Perceived marginalization and aggression: a longitudinal study with low-educated adolescents.

    PubMed

    Issmer, Christian; Wagner, Ulrich

    2015-03-01

    Social exclusion can evoke aggression. In the past two decades research has demonstrated this effect both for interpersonal and societal forms of exclusion. In addition, recent violent uprisings, like the London riots in August 2011, have been linked to social exclusion in the media. However, so far there is a lack of longitudinal studies which examine the aggression-enhancing effect of societal-level exclusion (i.e., marginalization) in disadvantaged groups. This research investigates the impact of perceived marginalization on aggression in a sample of N = 181 adolescents with a low educational background by means of a two-wave longitudinal study. The results of structural equation analyses are consistent with the hypothesis that perceived marginalization enhances aggression, and that this effect is mediated by the extent of negative societal meta-stereotypes. Furthermore, the reverse path from aggression to perceptions of marginalization is also significant. We discuss the implications of these findings and highlight practical consequences. © 2014 The British Psychological Society.

  16. Predicting missing biomarker data in a longitudinal study of Alzheimer disease.

    PubMed

    Lo, Raymond Y; Jagust, William J

    2012-05-01

    To investigate predictors of missing data in a longitudinal study of Alzheimer disease (AD). The Alzheimer's Disease Neuroimaging Initiative (ADNI) is a clinic-based, multicenter, longitudinal study with blood, CSF, PET, and MRI scans repeatedly measured in 229 participants with normal cognition (NC), 397 with mild cognitive impairment (MCI), and 193 with mild AD during 2005-2007. We used univariate and multivariable logistic regression models to examine the associations between baseline demographic/clinical features and loss of biomarker follow-ups in ADNI. CSF studies tended to recruit and retain patients with MCI with more AD-like features, including lower levels of baseline CSF Aβ(42). Depression was the major predictor for MCI dropouts, while family history of AD kept more patients with AD enrolled in PET and MRI studies. Poor cognitive performance was associated with loss of follow-up in most biomarker studies, even among NC participants. The presence of vascular risk factors seemed more critical than cognitive function for predicting dropouts in AD. The missing data are not missing completely at random in ADNI and likely conditional on certain features in addition to cognitive function. Missing data predictors vary across biomarkers and even MCI and AD groups do not share the same missing data pattern. Understanding the missing data structure may help in the design of future longitudinal studies and clinical trials in AD.

  17. Predicting missing biomarker data in a longitudinal study of Alzheimer disease

    PubMed Central

    Jagust, William J.; Aisen, Paul; Jack, Clifford R.; Toga, Arthur W.; Beckett, Laurel; Gamst, Anthony; Soares, Holly; C. Green, Robert; Montine, Tom; Thomas, Ronald G.; Donohue, Michael; Walter, Sarah; Dale, Anders; Bernstein, Matthew; Felmlee, Joel; Fox, Nick; Thompson, Paul; Schuff, Norbert; Alexander, Gene; DeCarli, Charles; Bandy, Dan; Chen, Kewei; Morris, John; Lee, Virginia M.-Y.; Korecka, Magdalena; Crawford, Karen; Neu, Scott; Harvey, Danielle; Kornak, John; Saykin, Andrew J.; Foroud, Tatiana M.; Potkin, Steven; Shen, Li; Buckholtz, Neil; Kaye, Jeffrey; Dolen, Sara; Quinn, Joseph; Schneider, Lon; Pawluczyk, Sonia; Spann, Bryan M.; Brewer, James; Vanderswag, Helen; Heidebrink, Judith L.; Lord, Joanne L.; Petersen, Ronald; Johnson, Kris; Doody, Rachelle S.; Villanueva-Meyer, Javier; Chowdhury, Munir; Stern, Yaakov; Honig, Lawrence S.; Bell, Karen L.; Morris, John C.; Mintun, Mark A.; Schneider, Stacy; Marson, Daniel; Griffith, Randall; Clark, David; Grossman, Hillel; Tang, Cheuk; Marzloff, George; Toledo-Morrell, Leylade; Shah, Raj C.; Duara, Ranjan; Varon, Daniel; Roberts, Peggy; Albert, Marilyn S.; Pedroso, Julia; Toroney, Jaimie; Rusinek, Henry; de Leon, Mony J; De Santi, Susan M; Doraiswamy, P. Murali; Petrella, Jeffrey R.; Aiello, Marilyn; Clark, Christopher M.; Pham, Cassie; Nunez, Jessica; Smith, Charles D.; Given, Curtis A.; Hardy, Peter; Lopez, Oscar L.; Oakley, MaryAnn; Simpson, Donna M.; Ismail, M. Saleem; Brand, Connie; Richard, Jennifer; Mulnard, Ruth A.; Thai, Gaby; Mc-Adams-Ortiz, Catherine; Diaz-Arrastia, Ramon; Martin-Cook, Kristen; DeVous, Michael; Levey, Allan I.; Lah, James J.; Cellar, Janet S.; Burns, Jeffrey M.; Anderson, Heather S.; Laubinger, Mary M.; Bartzokis, George; Silverman, Daniel H.S.; Lu, Po H.; Graff-Radford MBBCH, Neill R; Parfitt, Francine; Johnson, Heather; Farlow, Martin; Herring, Scott; Hake, Ann M.; van Dyck, Christopher H.; MacAvoy, Martha G.; Benincasa, Amanda L.; Chertkow, Howard; Bergman, Howard; Hosein, Chris; Black, Sandra; Graham, Simon; Caldwell, Curtis; Hsiung, Ging-Yuek Robin; Feldman, Howard; Assaly, Michele; Kertesz, Andrew; Rogers, John; Trost, Dick; Bernick, Charles; Munic, Donna; Wu, Chuang-Kuo; Johnson, Nancy; Mesulam, Marsel; Sadowsky, Carl; Martinez, Walter; Villena, Teresa; Turner, Scott; Johnson, Kathleen B.; Behan, Kelly E.; Sperling, Reisa A.; Rentz, Dorene M.; Johnson, Keith A.; Rosen, Allyson; Tinklenberg, Jared; Ashford, Wes; Sabbagh, Marwan; Connor, Donald; Jacobson, Sandra; Killiany, Ronald; Norbash, Alexander; Nair, Anil; Obisesan, Thomas O.; Jayam-Trouth, Annapurni; Wang, Paul; Lerner, Alan; Hudson, Leon; Ogrocki, Paula; DeCarli, Charles; Fletcher, Evan; Carmichael, Owen; Kittur, Smita; Mirje, Seema; Borrie, Michael; Lee, T-Y; Bartha, Dr Rob; Johnson, Sterling; Asthana, Sanjay; Carlsson, Cynthia M.; Potkin, Steven G.; Preda, Adrian; Nguyen, Dana; Tariot, Pierre; Fleisher, Adam; Reeder, Stephanie; Bates, Vernice; Capote, Horacio; Rainka, Michelle; Hendin, Barry A.; Scharre, Douglas W.; Kataki, Maria; Zimmerman, Earl A.; Celmins, Dzintra; Brown, Alice D.; Gandy, Sam; Marenberg, Marjorie E.; Rovner, Barry W.; Pearlson, Godfrey; Anderson, Karen; Saykin, Andrew J.; Santulli, Robert B.; Englert, Jessica; Williamson, Jeff D.; Sink, Kaycee M.; Watkins, Franklin; Ott, Brian R.; Wu, Chuang-Kuo; Cohen, Ronald; Salloway, Stephen; Malloy, Paul; Correia, Stephen; Rosen, Howard J.; Miller, Bruce L.; Mintzer, Jacobo

    2012-01-01

    Objective: To investigate predictors of missing data in a longitudinal study of Alzheimer disease (AD). Methods: The Alzheimer's Disease Neuroimaging Initiative (ADNI) is a clinic-based, multicenter, longitudinal study with blood, CSF, PET, and MRI scans repeatedly measured in 229 participants with normal cognition (NC), 397 with mild cognitive impairment (MCI), and 193 with mild AD during 2005–2007. We used univariate and multivariable logistic regression models to examine the associations between baseline demographic/clinical features and loss of biomarker follow-ups in ADNI. Results: CSF studies tended to recruit and retain patients with MCI with more AD-like features, including lower levels of baseline CSF Aβ42. Depression was the major predictor for MCI dropouts, while family history of AD kept more patients with AD enrolled in PET and MRI studies. Poor cognitive performance was associated with loss of follow-up in most biomarker studies, even among NC participants. The presence of vascular risk factors seemed more critical than cognitive function for predicting dropouts in AD. Conclusion: The missing data are not missing completely at random in ADNI and likely conditional on certain features in addition to cognitive function. Missing data predictors vary across biomarkers and even MCI and AD groups do not share the same missing data pattern. Understanding the missing data structure may help in the design of future longitudinal studies and clinical trials in AD. PMID:22491869

  18. Facilitating Development Research: Suggestions for Recruiting and Re-Recruiting Children and Families

    PubMed Central

    Hurwitz, Lisa B.; Schmitt, Kelly L.; Olsen, Megan K.

    2017-01-01

    Recruiting children and families for research studies can be challenging, and re-recruiting former participants for longitudinal research can be even more difficult, especially when a study was not prospectively designed to encompass continuous data collection. In this article, we explain how researchers can set up initial studies to potentially facilitate later waves of data collection; locate former study participants using newer, often digital, tools; schedule families using recruitment phone/email/mail scripts that highlight the many benefits to continued study participation; and confirm appointments with other digital tools. We draw from prior methodological and longitudinal pieces to provide suggestions to others wishing to re-recruit families for longitudinal studies. In addition, we draw upon our own experience conducting a non-prospective longitudinal study 6 years after an educational intervention, in which we successfully re-located 122 (90%) and interviewed 101 of 136 (83% of the located sample and 74% of the full original sample) parents and their early adolescent children. Although the majority of participants were recruited via original contact information (especially phone numbers), using a range of strategies to recruit (e.g., search engines focused on contact information, social media) and motivate participation (e.g., multifaceted phone/email/mail scheduling scripts, flexibility in location and means of participation) yielded a more desirable sample size at relatively low costs. PMID:28955265

  19. Self-Regulated Learning of Basic Arithmetic Skills: A Longitudinal Study

    ERIC Educational Resources Information Center

    Throndsen, Inger

    2011-01-01

    Background: Several studies have examined young primary school children's use of strategies when solving simple addition and subtraction problems. Most of these studies have investigated students' strategy use as if they were isolated processes. To date, we have little knowledge about how math strategies in young students are related to other…

  20. Personality Trait Development and Social Investment in Work

    PubMed Central

    Hudson, Nathan W.; Roberts, Brent W.; Lodi-Smith, Jennifer

    2012-01-01

    A longitudinal study of employed individuals was used to test the relationship between social investment at work—the act of cognitively and emotionally committing to one’s job—and longitudinal and cross-sectional personality trait development. Participants provided ratings of personality traits and social investment at work at two time-points, separated by approximately three years. Data were analyzed using latent change models. Cross-sectional results showed that extraversion, agreeableness, conscientiousness and emotional stability were related to social investment at work. Additionally, a positive association was found between longitudinal change in social investment in work and change in personality traits—especially conscientiousness. Finally, the correlated changes in social investment and personality traits were invariant across age groups, suggesting that personality traits remain malleable across the lifespan. PMID:22822278

  1. Procedural Fairness and Creativity: Does Voice Maintain People's Creative Vein over Time?

    ERIC Educational Resources Information Center

    Streicher, Bernhard; Jonas, Eva; Maier, Günter W.; Frey, Dieter; Spießberger, Anneliese

    2012-01-01

    Although some research suggests a link between procedural fairness and creativity, so far no study has directly tested whether a real manipulation of procedural fairness affects creativity. Additionally, research on procedural fairness effects consists mostly of unique studies, but more realistic, life-like longitudinal experiments with repeated…

  2. Assessing the Value of Additional Years of Schooling for the Non-Academically Inclined. Longitudinal Surveys of Australian Youth. Research Report 38

    ERIC Educational Resources Information Center

    Dockery, Alfred Michael

    2005-01-01

    In this report data from the 1995 Year 9 Cohort of the Longitudinal Surveys of Australian Youth (LSAY) is used along with a variety of empirical approaches to assess the benefits of additional years of schooling for various groups of youth conditional upon their estimated propensity to engage in further schooling. Background material is provided…

  3. Consumption of whole grains and cereal fiber in relation to cancer risk: a systematic review of longitudinal studies

    PubMed Central

    Makarem, Nour; Nicholson, Joseph M.; Bandera, Elisa V.; McKeown, Nicola M.

    2016-01-01

    Context: Evidence from previous reviews is supportive of the hypothesis that whole grains may protect against various cancers. However, the reviews did not report risk estimates for both whole grains and cereal fiber and only case–control studies were evaluated. It is unclear whether longitudinal studies support this conclusion. Objective: To evaluate associations between whole grains and cereal fiber in relation to risk of lifestyle-related cancers data from longitudinal studies was evaluated. Data Sources: The following 3 databases were systematically searched: PubMed, EMBASE, and Cochrane CENTRAL. Study Selection: A total of 43 longitudinal studies conducted in Europe and North America that reported multivariable-adjusted risk estimates for whole grains (n = 14), cereal fiber (n = 23), or both (n = 6) in relation to lifestyle-related cancers were included. Data Extraction: Information on study location, cohort name, follow-up duration, sample characteristics, dietary assessment method, risk estimates, and confounders was extracted. Data Synthesis: Of 20 studies examining whole grains and cancer, 6 studies reported a statistically significant 6%–47% reduction in risk, but 14 studies showed no association. Of 29 studies examining cereal fiber intake in relation to cancer, 8 showed a statistically significant 6%–49% reduction in risk, whereas 21 studies reported no association. Conclusions: This systematic review concludes that most studies were suggestive of a null association. Whole grains and cereal fiber may protect against gastrointestinal cancers, but these findings require confirmation in additional studies. PMID:27257283

  4. Upper-extremity phocomelia reexamined: a longitudinal dysplasia.

    PubMed

    Goldfarb, Charles A; Manske, Paul R; Busa, Riccardo; Mills, Janith; Carter, Peter; Ezaki, Marybeth

    2005-12-01

    In contrast to longitudinal deficiencies, phocomelia is considered a transverse, intercalated segmental dysplasia. Most patients demonstrate severe, but not otherwise classifiable, upper-extremity deformities, which usually cannot be placed into one of three previously described phocomelia groups. Additionally, these phocomelic extremities do not demonstrate true segmental deficits; the limb is also abnormal proximal and distal to the segmental defect. The purpose of this investigation was to present evidence that upper-extremity abnormalities in patients previously diagnosed as having phocomelia in fact represent a proximal continuum of radial or ulnar longitudinal dysplasia. The charts and radiographs of forty-one patients (sixty extremities) diagnosed as having upper-extremity phocomelia were reviewed retrospectively. On the basis of the findings on the radiographs, the disorders were categorized into three groups: (1) proximal radial longitudinal dysplasia, which was characterized by an absent proximal part of the humerus, a nearly normal distal part of the humerus, a completely absent radius, and a radial-sided hand dysplasia; (2) proximal ulnar longitudinal dysplasia, characterized by a short one-bone upper extremity that bifurcated distally and by severe hand abnormalities compatible with ulnar dysplasia; and (3) severe combined dysplasia, with type A characterized by an absence of the forearm segment (i.e., the radius and ulna) and type B characterized by absence of the arm and forearm (i.e., the hand attached to the thorax). Twenty-nine limbs in sixteen patients could be classified as having proximal radial longitudinal dysplasia. Systemic medical conditions such as thrombocytopenia-absent radius syndrome were common in those patients, but additional musculoskeletal conditions were rare. Twenty limbs in seventeen patients could be classified as having proximal ulnar longitudinal dysplasia. Associated musculoskeletal abnormalities, such as proximal femoral focal deficiency, were common in those patients. Eleven limbs in ten patients were identified as having severe combined dysplasia, which was type A in seven of them and type B in four. Four patients with severe combined dysplasia had congenital cardiac anomalies, and four had associated musculoskeletal abnormalities. Three of the four patients with the type-B disorder had a contralateral ulnar longitudinal dysplasia. We propose that cases previously classified as upper-extremity phocomelia represent a spectrum of severe longitudinal dysplasia, as none of the sixty extremities that we studied demonstrated a true intercalary deficiency. These findings have both developmental and genetic implications.

  5. LONGITUDINAL FOLLOW-UP OF LATE-ONSET ALZHEIMER DISEASE FAMILIES

    PubMed Central

    Carney, R.M.; Slifer, M.A.; Lin, P.I.; Gaskell, P. C.; Scott, W. K.; Potocky, C.F.; Hulette, C. M.; Welsh-Bohmer, K. A.; Schmechel, D. E.; Vance, J.M.; Pericak-Vance, M. A.

    2009-01-01

    Historically, data for genetic studies are collected at one time point. However, for diseases with late onset or with complex phenotypes, such as Alzheimer disease (AD), restricting diagnosis to a single ascertainment contact may not be sufficient. Affection status may change over time, and some initial diagnoses may be inconclusive. Follow-up provides the opportunity to resolve these complications. However, to date, previous studies have not formally demonstrated that longitudinally re-contacting families is practical or productive. To update data initially collected for linkage analysis of late-onset Alzheimer disease (LOAD), we successfully re-contacted 63 of 81 (78%) multiplex families (two to 17 years after ascertainment). Clinical status changed for 73 of the 230 (32%) non-affected participants. Additionally, expanded family history identified 20 additional affected individuals to supplement the data set. Furthermore, fostering ongoing relationships with participating families helped recruit 101 affected participants into an autopsy and tissue donation program. Despite similar presentations, discordance between clinical diagnosis and neuropathologic diagnosis was observed in 28% of those with tissue diagnoses. Most of the families were successfully re-contacted, and significant refinement and supplementation of the data was achieved. We concluded that serial contact with longitudinal evaluation of families has significant implications for genetic analyses. PMID:18361431

  6. Predicting longitudinal trajectories of health probabilities with random-effects multinomial logit regression.

    PubMed

    Liu, Xian; Engel, Charles C

    2012-12-20

    Researchers often encounter longitudinal health data characterized with three or more ordinal or nominal categories. Random-effects multinomial logit models are generally applied to account for potential lack of independence inherent in such clustered data. When parameter estimates are used to describe longitudinal processes, however, random effects, both between and within individuals, need to be retransformed for correctly predicting outcome probabilities. This study attempts to go beyond existing work by developing a retransformation method that derives longitudinal growth trajectories of unbiased health probabilities. We estimated variances of the predicted probabilities by using the delta method. Additionally, we transformed the covariates' regression coefficients on the multinomial logit function, not substantively meaningful, to the conditional effects on the predicted probabilities. The empirical illustration uses the longitudinal data from the Asset and Health Dynamics among the Oldest Old. Our analysis compared three sets of the predicted probabilities of three health states at six time points, obtained from, respectively, the retransformation method, the best linear unbiased prediction, and the fixed-effects approach. The results demonstrate that neglect of retransforming random errors in the random-effects multinomial logit model results in severely biased longitudinal trajectories of health probabilities as well as overestimated effects of covariates on the probabilities. Copyright © 2012 John Wiley & Sons, Ltd.

  7. Assessment of Thermal Performance of Functionally Graded Materials in Longitudinal Fins

    NASA Astrophysics Data System (ADS)

    Hassanzadeh, R.; Bilgili, M.

    2018-01-01

    Assessment of the thermal characteristics of materials in heat exchangers with longitudinal fins is performed in the case where a conventional homogeneous material of a longitudinal fin is replaced by a functionally graded one, in which the fin material properties, such as the conductivity, are assumed to be graded as linear and power-law functions along the normal axis from the fin base to the fin tip. The resulting equations are calculated under two (Dirichlet and Neumann) boundary conditions. The equations are solved by an approximate analytical method with the use of the mean value theorem. The results show that the inhomogeneity index of a functionally graded material plays an important role for the thermal energy characteristics in such heat exchangers. In addition, it is observed that the use of such a material in longitudinal fins enhances the rate of heat transfer between the fin surface and surrounding fluid. Hopefully, the results obtained in the study will arouse interest of designers in heat exchange industry.

  8. Regulation of body growth by microRNAs.

    PubMed

    Lui, Julian C

    2017-11-15

    Regulation of body growth remains a fascinating and unresolved biological mystery. One key component of body growth is skeletal and longitudinal bone growth. Children grow taller because their bones grew longer, and the predominant driver of longitudinal bone growth is a cartilaginous structure found near the ends of long bone named the growth plate. Numerous recent studies have started to unveil the importance of microRNAs in regulation of growth plate functions, therefore contributing to regulation of linear growth. In addition to longitudinal growth, other organs in our body need to increase in size and cell number as we grow, and the regulation of organ growth involves both systemic factors like hormones; and other intrinsic mechanisms, which we are just beginning to understand. This review aims to summarize some recent important findings on how microRNAs are involved in both of these processes: the regulation of longitudinal bone growth, and the regulation of organs and overall body growth. Published by Elsevier B.V.

  9. The Longitudinal Association Between Competitive Video Game Play and Aggression Among Adolescents and Young Adults.

    PubMed

    Adachi, Paul J C; Willoughby, Teena

    2016-11-01

    The longitudinal association between competitive video game play and aggression among young adults and adolescents was examined. Young adults (N = 1,132; M age  = 19 years) were surveyed annually over 4 years about their video game play and aggression, and data from a 4-year longitudinal study of adolescents (N = 1,492; M age  = 13 years) was reanalyzed. The results demonstrated a longitudinal association between competitive video game play and aggressive behavior among both age groups. In addition, competitive video game play predicted higher levels of aggressive affect over time, which, in turn, predicted higher levels of aggressive behavior over time, suggesting that aggressive affect was a mechanism of this link. These findings highlight the importance of investigating competitive elements of video game play that may predict aggression over time. © 2016 The Authors. Child Development © 2016 Society for Research in Child Development, Inc.

  10. Risky online behaviors among adolescents: Longitudinal relations among problematic Internet use, cyberbullying perpetration, and meeting strangers online.

    PubMed

    Gámez-Guadix, Manuel; Borrajo, Erika; Almendros, Carmen

    2016-03-01

    Background and aims This study aims to analyze the cross-sectional and longitudinal relationship between three major risky online behaviors during adolescence: problematic Internet use, cyberbullying perpetration, and meeting strangers online. An additional objective was to study the role of impulsivity-irresponsibility as a possible explanatory variable of the relationships between these risky online behaviors. Methods The study sample was 888 adolescents that completed self-report measures at time 1 and time 2 with an interval of 6 months. Results The findings showed a significant cross-sectional relationship between the risky online behaviors analyzed. At the longitudinal level, problematic Internet use at time 1 predicted an increase in the perpetration of cyberbullying and meeting strangers online at time 2. Furthermore, meeting strangers online increased the likelihood of cyberbullying perpetration at time 2. Finally, when impulsivity-irresponsibility was included in the model as an explanatory variable, the relationships previously found remained significant. Discussion These results extend traditional problem behavior theory during adolescence, also supporting a relationship between different risky behaviors in cyberspace. In addition, findings highlighted the role of problematic Internet use, which increased the chances of developing cyberbullying perpetration and meeting strangers online over time. However, the results suggest a limited role of impulsivity-irresponsibility as an explicative mechanism. Conclusions The findings suggest that various online risk activities ought to be addressed together when planning assessment, prevention and intervention efforts.

  11. Reciprocal relations between workplace bullying, anxiety, and vigor: a two-wave longitudinal study.

    PubMed

    Rodríguez-Muñoz, Alfredo; Moreno-Jiménez, Bernardo; Sanz-Vergel, Ana Isabel

    2015-01-01

    Workplace bullying has been classified as an extreme social stressor in work contexts and has been repeatedly linked to several negative consequences. However, little research has examined reversed or reciprocal relations of bullying and outcomes. We conducted a two-wave longitudinal study with a time lag of six months. The study sample consisted of 348 employees of the Spanish workforce. The present study examined longitudinal relationships between workplace bullying, psychological health, and well-being. On the basis of conservation of resources theory, we hypothesized that we would find reciprocal relations among study variables over time. Results of cross-lagged structural equation modeling analyses supported our hypotheses. Specifically, it was found that Time 1 (T1) workplace bullying was negatively related to Time 2 (T2) vigor and positively related to T2 anxiety. Additionally, T1 anxiety and vigor had an effect on T2 workplace bullying. Overall, these findings support the validity of the theoretical models postulating a reciprocal bullying-outcome relationship, rather than simple one-way causal pathways approaches.

  12. A cross-lagged structural equation model of relational aggression, physical aggression, and peer status in a Chinese culture.

    PubMed

    Tseng, Wan-Ling; Banny, Adrienne M; Kawabata, Yoshito; Crick, Nicki R; Gau, Susan Shur-Fen

    2013-01-01

    This short-term longitudinal study examined the associations among relational aggression, physical aggression, and peer status (i.e., acceptance, rejection, and perceived popularity) across three time points, six months apart, in a Taiwanese sample. Participants were 198 fifth grade students (94 girls and 104 boys; Mean age = 10.35 years) from Taipei, Taiwan. Study variables were assessed using peer nomination procedure. Results from the cross-lagged structural equation models demonstrated that there were longitudinal associations between relational aggression and each of the peer status constructs while only one longitudinal association was found for physical aggression such that physical aggression positively predicted subsequent peer rejection. The longitudinal associations did not vary with gender. Results also showed high stabilities of relational aggression, physical aggression, and the three peer status constructs over 1 year as well as high concurrent association between relational and physical aggression. In addition, relational aggression and physical aggression were concurrently related to less acceptance, more rejection, and less perceived popularity, especially at the outset of the study. Findings of this study demonstrated both similarities and differences in relation to previous literature in primarily Western cultures. This study also highlights the bidirectional and complex nature of the association between aggression and peer status, which appears to depend on the form of aggression and on the particular indicator of peer status under study. Copyright © 2013 Wiley Periodicals, Inc.

  13. Physical Activity and Motor Competence Present a Positive Reciprocal Longitudinal Relationship Across Childhood and Early Adolescence.

    PubMed

    Lima, Rodrigo A; Pfeiffer, Karin; Larsen, Lisbeth R; Bugge, Anna; Moller, Niels C; Anderson, Lars B; Stodden, David F

    2017-06-01

    The current study evaluated the reciprocal longitudinal relationship between physical activity (PA) and motor competence (MC) and the potential mediation of cardiorespiratory endurance across 7 years. This was a 7-year longitudinal study, the Copenhagen School Child Intervention Study (CoSCIS), with 3 measuring points [mean ages (in years) and respective sample size: 6.75 ± 0.37, n = 696; 9.59 ± 1.07, n = 617; 13.35 ± 0.34, n = 513]. PA was assessed using accelerometers. MC was evaluated by the Körperkoordinationstest für Kinder (KTK) test battery. Cardiorespiratory fitness (VO 2 peak) was evaluated using a continuous running protocol until exhaustion. Structural equation modeling was performed to evaluate the longitudinal associations. Vigorous PA (VPA) and MC presented reciprocal longitudinal association during the 7-year follow-up (VPA → MC; β = 0.18; 95% CI: 0.10, 0.26; MC → VPA; β = 0.14; 95% CI: 0.08, 0.21). In addition, VO 2 peak mediated the relationship in both directions (VPA → MC; β = 0.09; 95% CI: 0.06, 0.12; MC → VPA; β = 0.06; 95% CI: 0.03, 0.09). PA and MC presented a positive reciprocal relationship across childhood through early adolescence and VO 2 peak mediated the association in both directions. Interventions targeting to increase PA in children and adolescents should also address the development of MC skills because of the clear positive feedback loop between PA and MC.

  14. Longitudinal Analysis of Mouse SDOCT Volumes

    PubMed Central

    Antony, Bhavna J.; Carass, Aaron; Lang, Andrew; Kim, Byung-Jin; Zack, Donald J.; Prince, Jerry L.

    2017-01-01

    Spectral-domain optical coherence tomography (SDOCT), in addition to its routine clinical use in the diagnosis of ocular diseases, has begun to find increasing use in animal studies. Animal models are frequently used to study disease mechanisms as well as to test drug efficacy. In particular, SDOCT provides the ability to study animals longitudinally and non-invasively over long periods of time. However, the lack of anatomical landmarks makes the longitudinal scan acquisition prone to inconsistencies in orientation. Here, we propose a method for the automated registration of mouse SDOCT volumes. The method begins by accurately segmenting the blood vessels and the optic nerve head region in the scans using a pixel classification approach. The segmented vessel maps from follow-up scans were registered using an iterative closest point (ICP) algorithm to the baseline scan to allow for the accurate longitudinal tracking of thickness changes. Eighteen SDOCT volumes from a light damage model study were used to train a random forest utilized in the pixel classification step. The area under the curve (AUC) in a leave-one-out study for the retinal blood vessels and the optic nerve head (ONH) was found to be 0.93 and 0.98, respectively. The complete proposed framework, the retinal vasculature segmentation and the ICP registration, was applied to a secondary set of scans obtained from a light damage model. A qualitative assessment of the registration showed no registration failures. PMID:29138527

  15. Longitudinal analysis of mouse SDOCT volumes

    NASA Astrophysics Data System (ADS)

    Antony, Bhavna J.; Carass, Aaron; Lang, Andrew; Kim, Byung-Jin; Zack, Donald J.; Prince, Jerry L.

    2017-03-01

    Spectral-domain optical coherence tomography (SDOCT), in addition to its routine clinical use in the diagnosis of ocular diseases, has begun to fund increasing use in animal studies. Animal models are frequently used to study disease mechanisms as well as to test drug efficacy. In particular, SDOCT provides the ability to study animals longitudinally and non-invasively over long periods of time. However, the lack of anatomical landmarks makes the longitudinal scan acquisition prone to inconsistencies in orientation. Here, we propose a method for the automated registration of mouse SDOCT volumes. The method begins by accurately segmenting the blood vessels and the optic nerve head region in the scans using a pixel classification approach. The segmented vessel maps from follow-up scans were registered using an iterative closest point (ICP) algorithm to the baseline scan to allow for the accurate longitudinal tracking of thickness changes. Eighteen SDOCT volumes from a light damage model study were used to train a random forest utilized in the pixel classification step. The area under the curve (AUC) in a leave-one-out study for the retinal blood vessels and the optic nerve head (ONH) was found to be 0.93 and 0.98, respectively. The complete proposed framework, the retinal vasculature segmentation and the ICP registration, was applied to a secondary set of scans obtained from a light damage model. A qualitative assessment of the registration showed no registration failures.

  16. A rod type linear ultrasonic motor utilizing longitudinal traveling waves: proof of concept

    NASA Astrophysics Data System (ADS)

    Wang, Liang; Wielert, Tim; Twiefel, Jens; Jin, Jiamei; Wallaschek, Jörg

    2017-08-01

    This paper proposes a non-resonant linear ultrasonic motor utilizing longitudinal traveling waves. The longitudinal traveling waves in the rod type stator are generated by inducing longitudinal vibrations at one end of the waveguide and eliminating reflections at the opposite end by a passive damper. Considering the Poisson’s effect, the stator surface points move on elliptic trajectories and the slider is driven forward by friction. In contrast to many other flexural traveling wave linear ultrasonic motors, the driving direction of the proposed motor is identical to the wave propagation direction. The feasibility of the motor concept is demonstrated theoretically and experimentally. First, the design and operation principle of the motor are presented in detail. Then, the stator is modeled utilizing the transfer matrix method and verified by experimental studies. In addition, experimental parameter studies are carried out to identify the motor characteristics. Finally, the performance of the proposed motor is investigated. Overall, the results indicate very dynamic drive characteristics. The motor prototype achieves a maximum mean velocity of 115 mm s-1 and a maximum load of 0.25 N. Thereby, the start-up and shutdown times from the maximum speed are lower than 5 ms.

  17. Moral Disengagement among Serious Juvenile Offenders: A Longitudinal Study of the Relations between Morally Disengaged Attitudes and Offending

    ERIC Educational Resources Information Center

    Shulman, Elizabeth P.; Cauffman, Elizabeth; Piquero, Alex R.; Fagan, Jeffrey

    2011-01-01

    The present study investigates the relation between moral disengagement--one's willingness to conditionally endorse transgressive behavior--and ongoing offending in a sample of adolescent male felony offenders (N = 1,169). In addition, the study attempts to rule out callous-unemotional traits as a third variable responsible for observed…

  18. Perfectionistic concerns predict increases in adolescents' anxiety symptoms: a three-wave longitudinal study.

    PubMed

    Damian, Lavinia E; Negru-Subtirica, Oana; Stoeber, Joachim; Băban, Adriana

    2017-09-01

    Although perfectionism has been proposed to be a risk factor for the development of anxiety, research on perfectionism and anxiety symptoms in adolescents is scarce and inconclusive. The aim of the present study was to investigate whether the two higher-order dimensions of perfectionism - perfectionistic strivings and perfectionistic concerns - predict the development and maintenance of anxiety symptoms. An additional aim of the present study was to examine potential reciprocal effects of anxiety symptoms predicting increases in perfectionism. The study used a longitudinal design with three waves spaced 4-5 months apart. A non-clinical sample of 489 adolescents aged 12-19 years completed a paper-and-pencil questionnaire. As expected, results showed a positive effect from perfectionistic concerns to anxiety symptoms, but the effect was restricted to middle-to-late adolescents (16-19 years old): Perfectionistic concerns predicted longitudinal increases in adolescents' anxiety symptoms, whereas perfectionistic strivings did not. Furthermore, anxiety symptoms did not predict increases in perfectionism. Implications for the understanding of the relationship between perfectionism and anxiety symptoms are discussed.

  19. Multilevel Models for Intensive Longitudinal Data with Heterogeneous Autoregressive Errors: The Effect of Misspecification and Correction with Cholesky Transformation

    PubMed Central

    Jahng, Seungmin; Wood, Phillip K.

    2017-01-01

    Intensive longitudinal studies, such as ecological momentary assessment studies using electronic diaries, are gaining popularity across many areas of psychology. Multilevel models (MLMs) are most widely used analytical tools for intensive longitudinal data (ILD). Although ILD often have individually distinct patterns of serial correlation of measures over time, inferences of the fixed effects, and random components in MLMs are made under the assumption that all variance and autocovariance components are homogenous across individuals. In the present study, we introduced a multilevel model with Cholesky transformation to model ILD with individually heterogeneous covariance structure. In addition, the performance of the transformation method and the effects of misspecification of heterogeneous covariance structure were investigated through a Monte Carlo simulation. We found that, if individually heterogeneous covariances are incorrectly assumed as homogenous independent or homogenous autoregressive, MLMs produce highly biased estimates of the variance of random intercepts and the standard errors of the fixed intercept and the fixed effect of a level 2 covariate when the average autocorrelation is high. For intensive longitudinal data with individual specific residual covariance, the suggested transformation method showed lower bias in those estimates than the misspecified models when the number of repeated observations within individuals is 50 or more. PMID:28286490

  20. High School Learning, Vocational Tracking, and What Then? Contractor Report.

    ERIC Educational Resources Information Center

    Wiley, David E.; Harnischfeger, Annegret

    The National Longitudinal Study of the High School Class of 1972 collected data on the backgrounds, experiences, attitudes, and plans of 16,683 students who were high school seniors at 1,044 schools in 1972. In addition, three followup studies focused on the work experiences, education and training, military service, family status, life…

  1. Moderators of the Dynamic Link between Alcohol Use and Aggressive Behavior among Adolescent Males

    ERIC Educational Resources Information Center

    White, Helene Raskin; Fite, Paula; Pardini, Dustin; Mun, Eun-Young; Loeber, Rolf

    2013-01-01

    Although longitudinal evidence has linked alcohol use with aggressive behavior during adolescence, most studies have failed to adequately control for the numerous between-individual differences that may underlie this association. In addition, few studies of adolescents have examined whether the nature of the within-individual association between…

  2. Performance and Stability Characteristics of a Uni-Element Swirl Injector for Oxygen-Rich Stage Combustion Cycles

    NASA Technical Reports Server (NTRS)

    Pal, S.; Kalitan, D.; Woodward, R. D.; Santoro, R. J.

    2004-01-01

    A uni-element liquid propellant combustion performance and instability study for liquid RP-1 and hot oxygen-rich pre-burner products was conducted, at a chamber pressure of about 1000 psi. using flush and recessed swirl injectors. High-frequency pressure transducer measurements were analyzed to yield the characteristic frequencies which were compared to expected frequencies of the chamber. Modes, which were discovered to be present within the main chamber included, the first longitudinal, detected at approximately 1950 Hz, and the second longitudinal mode at approximately 3800 Hz. An additional first longitudinal quarter wave mode was measured at a frequency of approximately 23000 Hz for the recessed swirl injector configuration. The characteristic instabilities resulting from these experiments were relatively weak averaging 0.2% to 0.3% of the chamber pressure.

  3. Peer substance use as a mediator between early pubertal timing and adolescent substance use: longitudinal associations and moderating effect of maltreatment.

    PubMed

    Negriff, Sonya; Trickett, Penelope K

    2012-11-01

    Early pubertal timing has received considerable empirical support as a risk for adolescent substance use. However, few studies have examined the mediators linking these variables. Therefore, the aims of this study were (1) to examine peer substance use as a mediator between pubertal timing and adolescent substance use longitudinally and (2) to test gender and maltreatment experience as moderators of the mediational model. Data were obtained from time 1, 2, and 3 of a longitudinal study of maltreatment and development. At time 1 the sample was comprised of 303 maltreated and 151 comparison children aged 9-13 years (213 females and 241 males). Longitudinal mediation was tested using structural equation modeling and moderating effects were tested using multiple group analysis. Peer substance use mediated the relationship between early pubertal timing and later adolescent substance use for the total sample. Moderation analyses indicated this significant indirect effect did not differ for males and females. However, it did differ for maltreated versus comparison adolescents with the mediational effect only remaining significant for the comparison group. This is one of the first studies to examine peer substance use as a mediator of pubertal timing and adolescent substance use using a longitudinal design. Early maturing males are at equal risk to early maturing females for interacting with peers that may draw them into substance use. Additionally, the findings indicate that while peers are mediators for comparison adolescents a different mechanism may link early puberty to substance use for maltreated adolescents. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  4. Adverse Consequences of School Mobility for Children in Foster Care: A Prospective Longitudinal Study

    ERIC Educational Resources Information Center

    Pears, Katherine C.; Kim, Hyoun K.; Buchanan, Rohanna; Fisher, Philip A.

    2015-01-01

    Few prospective studies have examined school mobility in children in foster care. This study described the school moves of 86 such children and 55 community comparison children (primarily Caucasian), living in a medium-sized metropolitan area in the Pacific Northwest who were approximately 3 to 6 years old at the study start. Additionally, the…

  5. Time Outdoors at Specific Ages During Early Childhood and the Risk of Incident Myopia.

    PubMed

    Shah, Rupal L; Huang, Yu; Guggenheim, Jeremy A; Williams, Cathy

    2017-02-01

    Time outdoors during childhood is negatively associated with incident myopia. Consequently, additional time outdoors has been suggested as a public health intervention to reduce the prevalence of myopia. We investigated whether there were specific ages during early childhood when the time outdoors versus incident myopia association was strongest. Children participating in the Avon Longitudinal Study of Parents and Children (ALSPAC) were studied from age 2 to 15 years. Parentally reported time outdoors and time spent reading were assessed longitudinally in early childhood (ages 2, 3, 4, 5, 7, and 9 years). Noncycloplegic autorefraction was carried out longitudinally in later childhood (ages 10, 11, 12, and 15 years). Information was available for 2833 participants. Cox proportional hazards regression was used to test for association between time outdoors and incident myopia. From 3 years of age onward, greater time outdoors was associated with a reduced risk of incident myopia. The hazard ratio for myopia changed progressively from 0.90 (95% CI 0.83-0.98, P = 0.012) at age 3 years, to 0.86 (95% CI 0.78-0.93, P = 0.001) at age 9 years, for each additional SD of time spent outdoors per day. These associations were independent of two major risk factors for myopia: time reading and number of myopic parents. Additional time spent outdoors across the 3 to 9 years age range was associated with a reduced incidence of myopia between ages 10 and 15 years. There was a trend for the association to increase toward the older end of the 3 to 9 years range.

  6. Longitudinal structure of the equatorial ionosphere: Time evolution of the four-peaked EIA structure

    NASA Astrophysics Data System (ADS)

    Lin, C. H.; Hsiao, C. C.; Liu, J. Y.; Liu, C. H.

    2007-12-01

    Longitudinal structure of the equatorial ionosphere during the 24 h local time period is observed by the FORMOSAT-3/COSMIC (F3/C) satellite constellation. By binning the F3/C radio occultation observations during September and October 2006, global ionospheric total electron content (TEC) maps at a constant local time map (local time TEC map, referred as LT map) can be obtained to monitor the development and subsidence of the four-peaked longitudinal structure of the equatorial ionosphere. From LT maps, the four-peaked structure starts to develop at 0800-1000 LT and becomes most prominent at 1200-1600 LT. The longitudinal structure starts to subside after 2200-2400 LT and becomes indiscernible after 0400-0600 LT. In addition to TEC, ionospheric peak altitude also shows a four-peaked longitudinal structure with variation very similar to TEC during daytime. The four-peaked structure of the ionospheric peak altitude is indiscernible at night. With global local time maps of ionospheric TEC and peak altitude, we compare temporal variations of the longitudinal structure with variations of E × B drift from the empirical model. Our results indicate that the observations are consistent with the hypothesis that the four-peaked longitudinal structure is caused by the equatorial plasma fountain modulated by the E3 nonmigrating tide. Additionally, the four maximum regions show a tendency of moving eastward with propagation velocity of several 10 s m/s.

  7. PLCO Ovarian Phase III Validation Study — EDRN Public Portal

    Cancer.gov

    Our preliminary data indicate that the performance of CA 125 as a screening test for ovarian cancer can be improved upon by additional biomarkers. With completion of one additional validation step, we will be ready to test the performance of a consensus marker panel in a phase III validation study. Given the original aims of the PLCO trial, we believe that the PLCO represents an ideal longitudinal cohort offering specimens for phase III validation of ovarian cancer biomarkers.

  8. Pre-Quaternary divergence and subsequent radiation explain longitudinal patterns of genetic and morphological variation in the striped skink, Heremites vittatus.

    PubMed

    Baier, Felix; Schmitz, Andreas; Sauer-Gürth, Hedwig; Wink, Michael

    2017-06-09

    Many animal and plant species in the Middle East and northern Africa have a predominantly longitudinal distribution, extending from Iran and Turkey along the eastern Mediterranean coast into northern Africa. These species are potentially characterized by longitudinal patterns of biological diversity, but little is known about the underlying biogeographic mechanisms and evolutionary timescales. We examined these questions in the striped skink, Heremites vittatus, one such species with a roughly longitudinal distribution across the Middle East and northern Africa, by analyzing range-wide patterns of mitochondrial DNA (mtDNA) sequence and multi-trait morphological variation. The striped skink exhibits a basic longitudinal organization of mtDNA diversity, with three major mitochondrial lineages inhabiting northern Africa, the eastern Mediterranean coast, and Turkey/Iran. Remarkably, these lineages are of pre-Quaternary origin, and are characterized by p-distances of 9-10%. In addition, within each of these lineages a more recent Quaternary genetic diversification was observed, as evidenced by deep subclades and high haplotype diversity especially in the Turkish/Iranian and eastern Mediterranean lineages. Consistent with the genetic variation, our morphological analysis revealed that the majority of morphological traits show significant mean differences between specimens from northern Africa, the eastern Mediterranean coast, and Turkey/Iran, suggesting lineage-specific trait evolution. In addition, a subset of traits exhibits clinal variation along the eastern Mediterranean coast, potentially indicating selection gradients at the geographic transition from northern Africa to Anatolia. The existence of allopatric, morphologically and genetically divergent lineages suggests that Heremites vittatus might represent a complex with several taxa. Our work demonstrates that early divergence events in the Pliocene, likely driven by both climatic and geological factors, established the longitudinal patterns and distribution of Heremites vittatus. Subsequent radiation during the Pleistocene generated the genetic and morphological diversity observed today. Our study provides further evidence that longitudinal diversity patterns and species distributions in the Middle East and northern Africa were shaped by complex evolutionary processes, involving the region's intricate geological history, climatic oscillations, and the presence of the Sahara.

  9. Longitudinal relationship between Personal and Social Performance (PSP) and anxiety symptoms in schizophrenia.

    PubMed

    Park, In-Jo; Chung Jung, Dong; Suk-Hyun Hwang, Samuel; Yeon Jung, Hee; Yoon, Jin-Sang; Kim, Chul-Eung; Min Ahn, Yong; Sik Kim, Yong

    2016-01-15

    We aimed to examine the longitudinal relationship between the personal and social functioning and anxiety symptoms in patients with schizophrenia. For this purpose, we confirmed the validity of the anxiety subscale of the Symptom-Checklist-90-Revised (SCL-90-R) and then applied the latent growth modeling method for longitudinal causal relationships. Five hundred and seventy-eight patients diagnosed with schizophrenia were evaluated and 369 patients were included in the study at baseline. After conducting Rasch model analyses for the validation of the anxiety subscale in the SCL-90-R, we applied latent growth model to determine the causal relationship between the PSP and the anxiety symptoms. The validity of the anxiety subscale of the SCL-90-R was confirmed based on the Rasch rating model, where the criteria for Infit, Outfit, item difficulty, and point-measure correlations were satisfied. The results from the latent growth model showed that the intercept and slope (rate of change) of the PSP negatively predicted the slope of anxiety symptoms along the longitudinal trajectory. Together with previous studies examining the predictive role of anxiety symptoms on quality of life, our longitudinal findings lend evidence for bidirectional effects between quality of life and anxiety symptoms. The transactional nature of the relationship between anxiety symptoms and quality of life warrant further investigation using a longitudinal cross-lagged design. The anxiety subscale of the SCL-90-R may be utilized by clinicians and researcher to make inferences about quality of life in addition to assessing anxiety symptoms in patients with schizophrenia. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. The Impact of Prenatal Maternal Risk, Fearless Temperament and Early Parenting on Adolescent Callous-Unemotional Traits: A 14-Year Longitudinal Investigation

    ERIC Educational Resources Information Center

    Barker, Edward D.; Oliver, Bonamy R.; Viding, Essi; Salekin, Randall T.; Maughan, Barbara

    2011-01-01

    Objective: Proposals have been submitted to the DSM-V for the addition of a callous-unemotional (CU) specifier for conduct problem (CP) youth (CP/CU). While the addition of such a diagnostic category may aid in the identification of homogeneous CP subtypes, evidence on risks for the development of CP/CU remains limited. The present study sought to…

  11. The interplay of loneliness and depressive symptoms across adolescence: exploring the role of personality traits.

    PubMed

    Vanhalst, Janne; Klimstra, Theo A; Luyckx, Koen; Scholte, Ron H J; Engels, Rutger C M E; Goossens, Luc

    2012-06-01

    Based on current theories of depression, reciprocal links between loneliness and depressive symptoms are expected to occur. However, longitudinal studies on adolescent samples are scarce and have yielded conflicting results. The present five-wave longitudinal study from mid- to late adolescence (N=428, M age at T1=15.22 years; 47% female) examined the direction of effect between loneliness and depressive symptoms, using cross-lagged path analysis. In addition, the robustness of these prospective associations was tested by examining the role of the Big Five personality traits (i.e., extraversion, conscientiousness, agreeableness, neuroticism, and openness) as explaining factors and moderators. Results indicated that loneliness and depressive symptoms influenced one another reciprocally, and these reciprocal associations were not attributable to their mutual overlap with personality traits. In addition, neuroticism was found to be a moderator, in that the bidirectional effects between loneliness and depressive symptoms were only found in adolescents high in neuroticism. Practical implications are discussed, and suggestions for future research are outlined.

  12. Co-occurrences Between Adolescent Substance Use and Academic Performance: School Context Inuences a Multilevel-Longitudinal Perspective

    PubMed Central

    Andrade, Fernando H.

    2014-01-01

    A growing body of literature has linked substance use and academic performance exploring substance use as a predictor of academic performance or vice versa. This study uses a different approach conceptualizing substance use and academic performance as parallel outcomes and exploring two topics: its multilevel-longitudinal association and school contextual effects on both outcomes. Using multilevel Confirmatory Factor Analysis and multilevel-longitudinal analyses, the empirical estimates relied on 7843 students nested in 114 schools (Add Health study). The main finding suggests that the correlation between substance use and academic performance was positive at the school level in contraposition to the negative relationship at the individual level. Additional findings suggest a positive effect of a school risk factor on substance use and a positive effect of academic pressure on academic performance. These findings represent a contribution to our understanding of how schools could affect the relationship between academic performance and substance use. PMID:25057764

  13. Brain energy metabolism and neuroinflammation in ageing APP/PS1-21 mice using longitudinal 18F-FDG and 18F-DPA-714 PET imaging.

    PubMed

    Takkinen, Jatta S; López-Picón, Francisco R; Al Majidi, Rana; Eskola, Olli; Krzyczmonik, Anna; Keller, Thomas; Löyttyniemi, Eliisa; Solin, Olof; Rinne, Juha O; Haaparanta-Solin, Merja

    2017-08-01

    Preclinical animal model studies of brain energy metabolism and neuroinflammation in Alzheimer's disease have produced conflicting results, hampering both the elucidation of the underlying disease mechanism and the development of effective Alzheimer's disease therapies. Here, we aimed to quantify the relationship between brain energy metabolism and neuroinflammation in the APP/PS1-21 transgenic mouse model of Alzheimer's disease using longitudinal in vivo 18 F-FDG and 18 F-DPA-714) PET imaging and ex vivo brain autoradiography. APP/PS1-21 (TG, n = 9) and wild type control mice (WT, n = 9) were studied longitudinally every third month from age 6 to 15 months with 18 F-FDG and 18 F-DPA-714 with a one-week interval between the scans. Additional TG (n = 52) and WT (n = 29) mice were used for ex vivo studies. In vivo, the 18 F-FDG SUVs were lower and the 18 F-DPA-714 binding ratios relative to the cerebellum were higher in the TG mouse cortex and hippocampus than in WT mice at age 12 to 15 months ( p < 0.05). The ex vivo cerebellum binding ratios supported the results of the in vivo 18 F-DPA-714 studies but not the 18 F-FDG studies. This longitudinal PET study demonstrated decreased energy metabolism and increased inflammation in the brains of APP/PS1-21 mice compared to WT mice.

  14. Perceptions and Positionings of Colleges in New York City: A Longitudinal Study of Brand Images

    ERIC Educational Resources Information Center

    Clark, Sylvia D.

    2005-01-01

    A study of high school seniors' perceptions of colleges, conducted in 1979, was replicated 23 years later. The study affords an opportunity to examine perceptual changes over time and provides an additional perspective on the positioning of colleges, apart from other well-known surveys. This information may be useful for those involved in…

  15. Longitudinal Change in Happiness during Aging: The Predictive Role of Positive Expectancies

    ERIC Educational Resources Information Center

    Holahan, Carole K.; Holahan, Charles J.; Velasquez, Katherine E.; North, Rebecca J.

    2008-01-01

    This study employed hierarchical linear modeling to document the time course of happiness across 20 years from average ages of 66 to 86 among 717 members of the Terman Study of the Gifted. In addition, the study examined the role of positive expectancies about aging, assessed at an average age of 61, in enhancing happiness in aging. The results…

  16. The Brisbane Longitudinal Twin Study Pathways to Cannabis Use, Abuse and Dependence Project: Current status, preliminary results and future directions

    PubMed Central

    Gillespie, NA; Henders, AK; Davenport, TA; Hermens, DF; Wright, MJ; Martin, NG; Hickie, IB

    2013-01-01

    We describe the data being collected from the Brisbane Longitudinal Twin Study (BLTS) in Australia as part of the US National Institute on Drug Abuse (NIDA) funded project Pathways to Cannabis Use, Abuse and Dependence. The history, recruitment, assessment and retention of twin families in this project are described in detail along with preliminary findings and plans for future research. The goal of this NIDA project is to make a significant contribution to the discovery of quantitative trait loci (QTL) influencing cannabis use disorders. Although the focus is cannabis use, abuse and dependence in young adults, measures of comorbid illicit drug use disorders are also being collected. In addition, a variety of internalizing and externalizing disorders are being assessed, funded by support from the Australian National Health and Medical Research Council. Because these same twins have participated in numerous twin studies since 1992, future plans will include linking different phenotypes to investigate relationships between drug use, psychiatric disorders and psychological phenotypes within cross-sectional and longitudinal or developmental frameworks. PMID:23187020

  17. The Brisbane Longitudinal Twin Study: Pathways to Cannabis Use, Abuse, and Dependence project-current status, preliminary results, and future directions.

    PubMed

    Gillespie, Nathan A; Henders, Anjali K; Davenport, Tracy A; Hermens, Daniel F; Wright, Margie J; Martin, Nicholas G; Hickie, Ian B

    2013-02-01

    We describe the data being collected from the Brisbane Longitudinal Twin Study in Australia as part of the US National Institute on Drug Abuse (NIDA)-funded project, Pathways to Cannabis Use, Abuse and Dependence. The history, recruitment, assessment, and retention of twin families in this project are described in detail, along with preliminary findings and plans for future research. The goal of this NIDA project is to make a significant contribution to the discovery of quantitative trait loci influencing cannabis use disorders. Although the focus is cannabis use, abuse, and dependence in young adults, measures of comorbid illicit drug use disorders are also being collected. In addition, a variety of internalizing and externalizing disorders are being assessed, funded by support from the Australian National Health and Medical Research Council. Because these same twins have participated in numerous twin studies since 1992, future plans will include linking different phenotypes to investigate relationships between drug use, psychiatric disorders, and psychological phenotypes within cross-sectional and longitudinal or developmental frameworks.

  18. A longitudinal study of the relationship between work engagement and symptoms of anxiety and depression.

    PubMed

    Innstrand, Siw Tone; Langballe, Ellen Melbye; Falkum, Erik

    2012-02-01

    This longitudinal study examined the dynamic relationship between work engagement (vigour and dedication) and symptoms of anxiety and depression. A sample of 3475 respondents from eight different occupational groups (lawyers, physicians, nurses, teachers, church ministers, bus drivers, people working in advertising and people working in information technology) in Norway supplied data at two points in time with a 2-year time interval. The advantages of longitudinal design were utilized, including testing of reversed causation and controlling for unmeasured third variables. In general, the results showed that the hypothesized normal causal relationship was superior to a reversed causation model. In other words, this study supported the assumption that work engagement is more likely to be the antecedent for symptoms of depression and anxiety than the outcome. In particular, the vigour facet of work engagement provides lower levels of depression and anxiety 2 years later. However, additional analyses modelling unmeasured third variables indicate that unknown third variables may have created some spurious effects on the pattern of the observed relationship. Implications of the findings are discussed in the paper. Copyright © 2011 John Wiley & Sons, Ltd.

  19. Parental Warmth and Risks of Substance Use in Children with Attention-Deficit/Hyperactivity Disorder: Findings from a 10–12 Year Longitudinal Investigation

    PubMed Central

    Tandon, Mini; Tillman, Rebecca; Spitznagel, Edward; Luby, Joan

    2013-01-01

    Objective The study examined factors in the risk trajectory for Substance Use Disorder (SUD) over a 10–12 year period in children with ADHD. Method N=145 children between the ages of 7 and 16 with ADHD and healthy controls were assessed every 2 years for 10–12 years as part of a larger, longitudinal investigation. Onset of substance use disorder was examined using Cox proportional hazards modeling, and included child and parent psychopathology, and parental warmth as well as other key factors. Results Low paternal warmth and maternal SUD were predictors of SUD in n=59 ADHD participants after adjusting for gender, child ODD, paternal SUD, maternal/paternal ADHD, maternal/paternal major depressive disorder (MDD), maternal/paternal anxiety, and low maternal warmth in the Cox model. Conclusions Longitudinal study findings suggest that in addition to the established risk of ADHD and maternal SUD in development of child SUD, low paternal warmth is also associated with onset of SUD. This was evident after controlling for pertinent parent and child psychopathology. These findings suggest that paternal warmth warrants further investigation as a key target for novel interventions to prevent SUD in children with ADHD. More focused investigations examining paternal parenting factors in addition to parent and child psychopathology in the risk trajectory from ADHD to SUD are now warranted. PMID:24955084

  20. Parental Warmth and Risks of Substance Use in Children with Attention-Deficit/Hyperactivity Disorder: Findings from a 10-12 Year Longitudinal Investigation.

    PubMed

    Tandon, Mini; Tillman, Rebecca; Spitznagel, Edward; Luby, Joan

    2014-06-01

    The study examined factors in the risk trajectory for Substance Use Disorder (SUD) over a 10-12 year period in children with ADHD. N=145 children between the ages of 7 and 16 with ADHD and healthy controls were assessed every 2 years for 10-12 years as part of a larger, longitudinal investigation. Onset of substance use disorder was examined using Cox proportional hazards modeling, and included child and parent psychopathology, and parental warmth as well as other key factors. Low paternal warmth and maternal SUD were predictors of SUD in n=59 ADHD participants after adjusting for gender, child ODD, paternal SUD, maternal/paternal ADHD, maternal/paternal major depressive disorder (MDD), maternal/paternal anxiety, and low maternal warmth in the Cox model. Longitudinal study findings suggest that in addition to the established risk of ADHD and maternal SUD in development of child SUD, low paternal warmth is also associated with onset of SUD. This was evident after controlling for pertinent parent and child psychopathology. These findings suggest that paternal warmth warrants further investigation as a key target for novel interventions to prevent SUD in children with ADHD. More focused investigations examining paternal parenting factors in addition to parent and child psychopathology in the risk trajectory from ADHD to SUD are now warranted.

  1. Risky online behaviors among adolescents: Longitudinal relations among problematic Internet use, cyberbullying perpetration, and meeting strangers online

    PubMed Central

    Gámez-Guadix, Manuel; Borrajo, Erika; Almendros, Carmen

    2016-01-01

    Background and aims This study aims to analyze the cross-sectional and longitudinal relationship between three major risky online behaviors during adolescence: problematic Internet use, cyberbullying perpetration, and meeting strangers online. An additional objective was to study the role of impulsivity–irresponsibility as a possible explanatory variable of the relationships between these risky online behaviors. Methods The study sample was 888 adolescents that completed self-report measures at time 1 and time 2 with an interval of 6 months. Results The findings showed a significant cross-sectional relationship between the risky online behaviors analyzed. At the longitudinal level, problematic Internet use at time 1 predicted an increase in the perpetration of cyberbullying and meeting strangers online at time 2. Furthermore, meeting strangers online increased the likelihood of cyberbullying perpetration at time 2. Finally, when impulsivity–irresponsibility was included in the model as an explanatory variable, the relationships previously found remained significant. Discussion These results extend traditional problem behavior theory during adolescence, also supporting a relationship between different risky behaviors in cyberspace. In addition, findings highlighted the role of problematic Internet use, which increased the chances of developing cyberbullying perpetration and meeting strangers online over time. However, the results suggest a limited role of impulsivity–irresponsibility as an explicative mechanism. Conclusions The findings suggest that various online risk activities ought to be addressed together when planning assessment, prevention and intervention efforts. PMID:28092196

  2. Short sleep duration as a risk factor for hypercholesterolemia: analyses of the National Longitudinal Study of Adolescent Health.

    PubMed

    Gangwisch, James E; Malaspina, Dolores; Babiss, Lindsay A; Opler, Mark G; Posner, Kelly; Shen, Sa; Turner, J Blake; Zammit, Gary K; Ginsberg, Henry N

    2010-07-01

    To explore the relationship between sleep duration in adolescence and hypercholesterolemia in young adulthood. Experimental sleep restriction has been shown to significantly increase total cholesterol and LDL cholesterol levels in women. Short sleep duration has been found in cross sectional studies to be associated with higher total cholesterol and lower HDL cholesterol levels. Sleep deprivation could increase the risk for hypercholesterolemia by increasing appetite and dietary consumption of saturated fats, decreasing motivation to engage in regular physical activity, and increasing stress and resultant catecholamine induced lipolysis. No previous published population studies have examined the longitudinal relationship between sleep duration and high cholesterol. Multivariate longitudinal analyses stratified by sex of the ADD Health using logistic regression. United States nationally representative, school-based, probability-based sample. Adolescents (n = 14,257) in grades 7 to 12 at baseline (1994-95) and ages 18 to 26 at follow-up (2001-02). Among females, each additional hour of sleep was associated with a significantly decreased odds of being diagnosed with high cholesterol in young adulthood (OR = 0.85, 95% CI 0.75-0.96) after controlling for covariates. Additional sleep was associated with decreased, yet not statistically significant, odds ratios for hypercholesterolemia in males (OR = 0.91, 95% CI 0.79-1.05). Short sleep durations in adolescent women could be a significant risk factor for high cholesterol. Interventions that lengthen sleep could potentially serve as treatments and as primary preventative measures for hypercholesterolemia.

  3. A longitudinal study of students' academic self-concept in a streamed setting: the Singapore context.

    PubMed

    Liu, W C; Wang, C K J; Parkins, E J

    2005-12-01

    Although several studies support the existence of a negative stream effect on lower-ability stream students' academic self-concept, there is not enough longitudinal research evidence to preclude the possibility that the stream effect may only be temporary. In addition, not much is known about the effect of streaming on changes in students' academic self-concept over time. The main aims of the study were to examine the effect of streaming on (a) the students' academic self-concept immediately after the streaming process, and at yearly intervals for 3 consecutive years, and (b) the changes in students' academic self-concept over a 3 year period. The sample comprised 495 Secondary 1 students (approximate age 13) from three government coeducational schools in Singapore. A longitudinal survey using a self-reported questionnaire. Results showed that the lower-ability stream students had a more negative academic self-concept than the higher-ability stream students immediately after streaming, but they had a more positive academic self-concept 3 years after being streamed. In addition, it was established that the students' academic self-concept declined from Secondary 1 to Secondary 3. Nonetheless, the decline was more pronounced for the higher-ability stream students than the lower-ability stream students. Streaming may have a short-term negative impact on lower-ability stream students' academic self-concept. However, in the long run, being in the lower-ability stream may not be detrimental to their academic self-concept.

  4. Synergistic effect of interaction between perceived health and social activity on depressive symptoms in the middle-aged and elderly: a population-based longitudinal study.

    PubMed

    Chun, Sung-Youn; Han, Kyu-Tae; Lee, Seo Yoon; Kim, Chan Ok; Park, Eun-Cheol

    2015-03-13

    To examine the synergistic effect of interaction between perceived health and social activity on depressive symptoms. We investigated whether the interaction between perceived health and social activity has a synergistic effect on depressive symptoms in the middle-aged and elderly using data from 6590 respondents aged 45 and older in the Korean Longitudinal Study on Aging (KLoSA), 2006-2012. A generalised linear mixed-effects model was used to investigate the association in a longitudinal data form. Depressive symptoms were measured using the Center for Epidemiological Studies Depression 10 Scale (CES-D10). Perceived health and level of social activity were categorical variables with three values. Participation in six social activities was assessed. Interactions between perceived health status and social activity were statistically significant for almost all social activity/perceived health combinations. Addition of the interaction term significantly decreased CES-D10 scores, confirming the synergistic effect of the interaction between perceived health status and social activity ('normal×moderate', β=-0.1826; 'poor×moderate', β=-0.5739; 'poor×active', β=-0.8935). In addition, we performed stratified analyses by region: urban or rural. In urban respondents, the additional effect of the interaction term decreased CES-D10 scores and all social activity/perceived health combinations were statistically significant ('normal×moderate', β=-0.2578; 'normal×active', β=-0.3945; 'poor×moderate', β=-0.5739; 'poor×active', β=-0.8935). In rural respondents, only one social activity/perceived health combination was statistically significant, and the additional effect of the interaction term showed no consistent trend on CES-D10 scores. The interaction between perceived health and social activity has a synergistic effect on depressive symptoms; the additional effect of the interaction term significantly decreased CES-D10 scores in our models. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  5. A Longitudinal Study of the Associations among Adolescent Conflict Resolution Styles, Depressive Symptoms, and Romantic Relationship Longevity

    ERIC Educational Resources Information Center

    Ha, Thao; Overbeek, Geertjan; Cillessen, Antonius H. N.; Engels, Rutger C. M. E.

    2012-01-01

    This study investigated whether adolescents' conflict resolution styles mediated between depressive symptoms and relationship longevity. Data were used from a sample of 80 couples aged 13-19 years old (Mage = 15.48, SD = 1.16). At Time 1 adolescents reported their depressive symptoms and conflict resolution styles. Additionally, time until…

  6. The Effects of Professional Learning Communities on Student Achievement

    ERIC Educational Resources Information Center

    Burdett, John M.

    2009-01-01

    The purpose of this study was to examine data from the Early Childhood Longitudinal Study: Kindergarten Class of 1998-99 (ECLS-K) report, identify questions and statements that correlate to the dimensions of professional learning communities (PLCs), and determine the effect PLCs have on student achievement based on the ECLS-K data. In addition,…

  7. The Longitudinal Development of Oral Linguistic Complexity and Accuracy of Spanish Learner Language in Second-Year University Students

    ERIC Educational Resources Information Center

    Bajuniemi, Abby Louise

    2015-01-01

    To date, few studies have investigated the production of linguistic complexity and accuracy with naturalistic data. Very often, the data are obtained in a laboratory or laboratory-style settings, with tasks defined by the researcher rather than the instructor (Hatch, 1978; Seedhouse, 2004). Additionally, replicability of studies that investigate…

  8. Exploring the Relationship between State Financial Aid Policy and Postsecondary Enrollment Choices: A Focus on Income and Race Differences

    ERIC Educational Resources Information Center

    Kim, Jiyun

    2012-01-01

    This study explores the relationship between state financial aid policies and postsecondary enrollment for high school graduates (or equivalent diploma holders). Utilizing an event history modeling for a nationally representative sample from the National Education Longitudinal Study (NELS:88/2000) in addition to state-level policy variables, this…

  9. Investigating the Role of Psychological Contract Breach on Career Success: Convergent Evidence from Two Longitudinal Studies

    ERIC Educational Resources Information Center

    Restubog, Simon Lloyd D.; Bordia, Prashant; Bordia, Sarbari

    2011-01-01

    The current study extends past research by examining leader-member exchange as a mediator of the relationship between employee reports of psychological contract breach and career success. In addition, we tested a competing perspective in which we proposed that performance mediators (i.e., in-role performance and organizational citizenship…

  10. Scaffolding during the Formal Assessment of Young EAL Learners: A New Zealand Case Study

    ERIC Educational Resources Information Center

    Booth, Dawn

    2012-01-01

    Despite growing interest in the theorisation of teacher-based assessment (TBA), very little research has paid close attention to how teachers practice assessment embedded in real classroom contexts. This longitudinal study over one school term reports on the TBA of young learners with English as an additional language (EAL) in New Zealand primary…

  11. The Crucial First Year: A Longitudinal Study of Students' Motivational Development at a Swiss Business School

    ERIC Educational Resources Information Center

    Brahm, Taiga; Jenert, Tobias; Wagner, Dietrich

    2017-01-01

    In Switzerland, every student graduating from grammar school can begin to study at a university. This leads to high dropout rates. Although students' motivation is considered a strong predictor of performance, the development of motivation during students' transition from high school to university has rarely been investigated. Additionally, little…

  12. Adolescents' Exposure to Sexually Explicit Internet Material and Sexual Satisfaction: A Longitudinal Study

    ERIC Educational Resources Information Center

    Peter, Jochen; Valkenburg, Patti M.

    2009-01-01

    The aim of this study was to investigate, within a social comparison framework, the causal relationship between adolescents' use of sexually explicit Internet material (SEIM) and their sexual satisfaction. In addition, we tested which adolescents were most susceptible to a potential influence of SEIM on sexual satisfaction. Between May 2006 and…

  13. Racial Differences in Adolescent Distress: Differential Effects of the Family and Community for Blacks and Whites

    ERIC Educational Resources Information Center

    Wickrama, K. A. S.; Noh, Samuel; Bryant, Chalandra M.

    2005-01-01

    Using a sample of 15,885 adolescents derived from the National Longitudinal Study of Adolescent Health, this study examined (1) unique additive influences of race, family, and community and (2) various multiplicative influences among race, family, and community factors on adolescent distress. Community characteristics such as community poverty and…

  14. Parenting, Family Socioeconomic Status, and Child Executive Functioning: A Longitudinal Study

    ERIC Educational Resources Information Center

    Rochette, Émilie; Bernier, Annie

    2014-01-01

    Family socioeconomic status (SES) and the quality of maternal behavior are among the few identified predictors of child executive functioning (EF), and they have often been found to have interactive rather than additive effects on other domains of child functioning. The purpose of this study was to explore their interactive effects in the…

  15. Longitudinal, transcranial measurement of functional activation in the rat brain by diffuse correlation spectroscopy.

    PubMed

    Blanco, Igor; Zirak, Peyman; Dragojević, Tanja; Castellvi, Clara; Durduran, Turgut; Justicia, Carles

    2017-10-01

    Neural activity is an important biomarker for the presence of neurodegenerative diseases, cerebrovascular alterations, and brain trauma; furthermore, it is a surrogate marker for treatment effects. These pathologies may occur and evolve in a long time-period, thus, noninvasive, transcutaneous techniques are necessary to allow a longitudinal follow-up. In the present work, we have customized noninvasive, transcutaneous, diffuse correlation spectroscopy (DCS) to localize changes in cerebral blood flow (CBF) induced by neural activity. We were able to detect changes in CBF in the somatosensory cortex by using a model of electrical forepaw stimulation in rats. The suitability of DCS measurements for longitudinal monitoring was demonstrated by performing multiple sessions with the same animals at different ages (from 6 to 18 months). In addition, functional DCS has been cross-validated by comparison with functional magnetic resonance imaging (fMRI) in the same animals in a subset of the time-points. The overall results obtained with transcutaneous DCS demonstrates that it can be utilized in longitudinal studies safely and reproducibly to locate changes in CBF induced by neural activity in the small animal brain.

  16. Measuring positive and negative affect in older adults over 56 days: comparing trait level scoring methods using the partial credit model.

    PubMed

    Erbacher, Monica K; Schmidt, Karen M; Boker, Steven M; Bergeman, Cindy S

    2012-01-01

    Positive (PA) and negative affect (NA) are important constructs in health and well-being research. Good longitudinal measurement is crucial to conducting meaningful research on relationships between affect, health, and well-being across the lifespan. One common affect measure, the PANAS, has been evaluated thoroughly with factor analysis, but not with Racsh-based latent trait models (RLTMs) such as the Partial Credit Model (PCM), and not longitudinally. Current longitudinal RLTMs can computationally handle few occasions of data. The present study compares four methods of anchoring PCMs across 56 occasions to longitudinally evaluate the psychometric properties of the PANAS plus additional items. Anchoring item parameters on mean parameter values across occasions produced more desirable results than using no anchor, using first occasion parameters as anchors, or allowing anchor values to vary across occasions. Results indicated problems with NA items, including poor category utilization, gaps in the item distribution, and a lack of easy-to-endorse items. PA items had much more desirable psychometric qualities.

  17. Obesity and mobility disability in the older adult.

    PubMed

    Vincent, H K; Vincent, K R; Lamb, K M

    2010-08-01

    Mobility disability is becoming prevalent in the obese older population (> or = 60 years of age). We included a total of 13 cross-sectional and 15 longitudinal studies based on actual physical assessments of mobility in the obese older population in this review. We systematically examined existing evidence of which adiposity estimate best predicted mobility disability. Cross-sectional studies (82-4000 participants) showed poorer lower extremity mobility with increasing obesity severity in both men and women. All longitudinal studies (1-22 years) except for one, reported relationships between adiposity and declining mobility. While different physical tests made interpretation challenging, a consistent finding was that walking, stair climbing and chair rise ability were compromised with obesity, especially if the body mass index (BMI) exceeded 35 kg m(-2). More studies found that obese women were at an increased risk for mobility impairment than men. Existing evidence suggests that BMI and waist circumference are emerging as the more consistent predictors of the onset or worsening of mobility disability. Limited interventional evidence shows that weight loss is related with increased mobility and lower extremity function. Additional longitudinal studies are warranted that address overall body composition fat and muscle mass or change on future disability.

  18. Off-axis phonon and photon propagation in porous silicon superlattices studied by Brillouin spectroscopy and optical reflectance

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Parsons, L. C., E-mail: lcparsons@mun.ca; Andrews, G. T., E-mail: tandrews@mun.ca

    2014-07-21

    Brillouin light scattering experiments and optical reflectance measurements were performed on a pair of porous silicon-based optical Bragg mirrors which had constituent layer porosity ratios close to unity. For off-axis propagation, the phononic and photonic band structures of the samples were modeled as a series of intersecting linear dispersion curves. Zone-folding was observed for the longitudinal bulk acoustic phonon and the frequency of the probed zone-folded longitudinal phonon was shown to be dependent on the propagation direction as well as the folding order of the mode branch. There was no conclusive evidence of coupling between the transverse and the foldedmore » longitudinal modes. Two additional observed Brillouin peaks were attributed to the Rayleigh surface mode and a possible pseudo-surface mode. Both of these modes were dispersive, with the velocity increasing as the wavevector decreased.« less

  19. An introduction to analyzing dichotomous outcomes in a longitudinal setting: a NIDRR traumatic brain injury model systems communication.

    PubMed

    Pretz, Christopher R; Ketchum, Jessica M; Cuthbert, Jeffery P

    2014-01-01

    An untapped wealth of temporal information is captured within the Traumatic Brain Injury Model Systems National Database. Utilization of appropriate longitudinal analyses can provide an avenue toward unlocking the value of this information. This article highlights 2 statistical methods used for assessing change over time when examination of noncontinuous outcomes is of interest where this article focuses on investigation of dichotomous responses. Specifically, the intent of this article is to familiarize the rehabilitation community with the application of generalized estimating equations and generalized linear mixed models as used in longitudinal studies. An introduction to each method is provided where similarities and differences between the 2 are discussed. In addition, to reinforce the ideas and concepts embodied in each approach, we highlight each method, using examples based on data from the Rocky Mountain Regional Brain Injury System.

  20. Band transition and topological interface modes in 1D elastic phononic crystals.

    PubMed

    Yin, Jianfei; Ruzzene, Massimo; Wen, Jihong; Yu, Dianlong; Cai, Li; Yue, Linfeng

    2018-05-01

    In this report, we design a one-dimensional elastic phononic crystal (PC) comprised of an Aluminum beam with periodically arranged cross-sections to study the inversion of bulk bands due to the change of topological phases. As the geometric parameters of the unit cell varies, the second bulk band closes and reopens forming a topological transition point. This phenomenon is confirmed for both longitudinal waves and bending waves. By constructing a structural system formed by two PCs with different topological phases, for the first time, we experimentally demonstrate the existence of interface mode within the bulk band gap as a result of topological transition for both longitudinal and bending modes in elastic systems, although for bending modes, additional conditions have to be met in order to have the interface mode due to the dispersive nature of the bending waves in uniform media compared to the longitudinal waves.

  1. Who's the Boss? Patterns of Control in Adolescents' Sibling Relationships.

    PubMed

    Tucker, Corinna Jenkins; Updegraff, Kimberly A; Baril, Megan E

    2010-12-01

    The goals of this study were to examine longitudinal changes in perceived control in adolescents' sibling relationships and to describe the nature and correlates of three distinct control patterns: Firstborn dominant, equal, and secondborn dominant. Firstborn and secondborn adolescents in 184 predominately European-American families participated in home interviews and a series of phone interviews as part of a longitudinal a study of family relationships and adolescent development. Findings revealed changes in control over three years as well as sibling differences. In addition, different patterns of control were linked to qualities of the sibling relationship and to adolescent adjustment. The different roles that firstborn and secondborn siblings assume, and why these roles are linked to relationship experiences and adjustment, are discussed.

  2. Who’s the Boss? Patterns of Control in Adolescents’ Sibling Relationships

    PubMed Central

    Tucker, Corinna Jenkins; Updegraff, Kimberly A.; Baril, Megan E.

    2011-01-01

    The goals of this study were to examine longitudinal changes in perceived control in adolescents’ sibling relationships and to describe the nature and correlates of three distinct control patterns: Firstborn dominant, equal, and secondborn dominant. Firstborn and secondborn adolescents in 184 predominately European-American families participated in home interviews and a series of phone interviews as part of a longitudinal a study of family relationships and adolescent development. Findings revealed changes in control over three years as well as sibling differences. In addition, different patterns of control were linked to qualities of the sibling relationship and to adolescent adjustment. The different roles that firstborn and secondborn siblings assume, and why these roles are linked to relationship experiences and adjustment, are discussed. PMID:21857761

  3. Longitudinal effects of student mobility on three dimensions of elementary school engagement.

    PubMed

    Gruman, Diana H; Harachi, Tracy W; Abbott, Robert D; Catalano, Richard F; Fleming, Charles B

    2008-01-01

    Working within the developmental science research framework, this study sought to capture a dynamic and complex view of student mobility. Second- through fifth-grade data (N = 1,003, predominantly Caucasian) were drawn from a longitudinal study, and growth curve analyses allowed for the examination of mobility effects within the context of other factors that put children at risk, including behavior problems and family stress. School changes predicted declines in academic performance and classroom participation but not positive attitude toward school. Time-varying factors such as peer acceptance and teacher support had a positive influence on the growth trajectories of child outcomes. Additionally, teacher support had a particularly strong influence on positive attitudes toward school among children who had more school changes.

  4. Longitudinal Effects of Student Mobility on Three Dimensions of Elementary School Engagement

    PubMed Central

    Gruman, Diana H.; Harachi, Tracy W.; Abbott, Robert D.; Catalano, Richard F.; Fleming, Charles B.

    2013-01-01

    Working within the developmental science research framework, this study sought to capture a dynamic and complex view of student mobility. Second- through fifth-grade data (N = 1,003, predominantly Caucasian) were drawn from a longitudinal study, and growth curve analyses allowed for the examination of mobility effects within the context of other factors that put children at risk, including behavior problems and family stress. School changes predicted declines in academic performance and classroom participation but not positive attitude toward school. Time-varying factors such as peer acceptance and teacher support had a positive influence on the growth trajectories of child outcomes. Additionally, teacher support had a particularly strong influence on positive attitudes toward school among children who had more school changes. PMID:19037953

  5. The Longitudinal Joint Effect of Obesity and Major Depression on Work Performance Impairment

    PubMed Central

    Reijneveld, Sijmen A.; Penninx, Brenda W. J. H.; Schoevers, Robert A.; Bültmann, Ute

    2015-01-01

    Objectives. We examined the longitudinal effect of obesity, major depression, and their combination on work performance impairment (WPI). Methods. We collected longitudinal data (2004–2013) on 1726 paid employees from the Netherlands Study of Depression and Anxiety at baseline and 2-, 4-, and 6-year follow-up. We defined obesity with body mass index and waist circumference. We diagnosed major depression with the Composite International Diagnostic Interview 2.1. We assessed work performance impairment with a questionnaire for illness-associated costs. We used generalized estimating equations for modeling, and estimated interaction on the additive scale. Results. Obesity, abdominal obesity, and major depression were longitudinally associated with increased risk of high WPI. The combinations of obesity and major depression, and of abdominal obesity and major depression were associated with increased risk of high WPI (odds ratios of 2.36 [95% confidence interval = 1.61, 3.44] and 1.88 [95% confidence interval = 1.40, 2.53], respectively), but the relative excess risks attributable to interaction were nonsignificant. Conclusions. The longitudinal joint effect of obesity and major depression on high WPI implies that obesity intervention may be more beneficial for individuals with major depression than those without regarding risk of high WPI, if confirmed in a large, representative sample. PMID:25790401

  6. Regional gray matter volume increases following 7days of voluntary wheel running exercise: a longitudinal VBM study in rats.

    PubMed

    Sumiyoshi, Akira; Taki, Yasuyuki; Nonaka, Hiroi; Takeuchi, Hikaru; Kawashima, Ryuta

    2014-09-01

    The effects of physical exercise on brain morphology in rodents have been well documented in histological studies. However, to further understand when and where morphological changes occur in the whole brain, a noninvasive neuroimaging method allowing an unbiased, comprehensive, and longitudinal investigation of brain morphology should be used. In this study, we investigated the effects of 7days of voluntary wheel running exercise on regional gray matter volume (rGMV) using longitudinal voxel-based morphometry (VBM) in rats. Eighteen pairs of adult male naïve Wistar rats were randomized to the exercise or control condition (one rat for each condition from each pair). Each rat was scanned in a 7.0-T MRI scanner at three time points: before exercise, after 7days of exercise, and after 7days of follow-up. The T2-weighted MRI images were segmented using the rat brain tissue priors that were recently published by our laboratory, and the intra- and inter-subject template creation steps were followed. Longitudinal VBM analysis revealed significant increases in rGMV in the motor, somatosensory, association, and visual cortices in the exercise group. Among these brain regions, rGMV changes in the motor cortex were positively correlated with the total distance that was run during the 7days of exercise. In addition, the effects of 7days of exercise on rGMV persisted after 7days of follow-up. These results support the utility of a longitudinal VBM study in rats and provide new insights into experience-dependent structural brain plasticity in naïve adult animals. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Psychosocial Quality-of-Life, Lifestyle and Adiposity: A Longitudinal Study in Pre-schoolers (Ballabeina Study).

    PubMed

    Michels, Nathalie; Susi, Kriemler; Marques-Vidal, Pedro M; Nydegger, Andreas; Puder, Jardena J

    2016-06-01

    In obesity prevention, understanding psychosocial influences in early life is pivotal. Reviews reported contradictory results and a lack of longitudinal studies focusing on underlying lifestyle factors. This study tested whether psychosocial Quality-Of-Life (QOL) was associated with pre-schoolers' lifestyle and adiposity changes over one school year and whether lifestyle moderated the latter. It was hypothesised that QOL might not impact adiposity in everybody but that this might depend on preceding lifestyle. Longitudinal data from 291 Swiss pre-schoolers (initially 3.9-6.3 years) was available. The following measures were used in longitudinal regressions: psychosocial QOL by PedsQL, adiposity (BMI z-score, waist, fat%), diet (food frequency), sedentary time and accelerometer-based activity. Concerning lifestyle, low psychosocial QOL was only related to unfavourable changes in diet (less fruit β = 0.21 and more fat intake β = -0.28) and lower physical activity (β = 0.21). Longitudinal QOL-adiposity relations appeared only after moderation by lifestyle factors (beta-range 0.13-0.67). Low psychosocial QOL was associated with increased adiposity in children with an unhealthy diet intake or high sedentary time. By contrast, low psychosocial QOL was associated with decreasing adiposity in high fruit consumers or more physically active pre-schoolers. Results emphasise the need for testing moderation in the QOL-adiposity relation. An unhealthy diet can be a vulnerability factor and high physical activity a protective factor in QOL-related adiposity. Consequently, QOL and lifestyle should be targeted concurrently in multi-factorial obesity prevention. The environment should be an 'activity encouraging, healthy food zone' that minimises opportunities for stress-induced eating. In addition, appropriate stress coping skills should be acquired.

  8. Nonlinear mechanisms of two-dimensional wave-wave transformations in the initially coupled acoustic structure

    NASA Astrophysics Data System (ADS)

    Vorotnikov, K.; Starosvetsky, Y.

    2018-01-01

    The present study concerns two-dimensional nonlinear mechanisms of bidirectional and unidirectional channeling of longitudinal and shear waves emerging in the locally resonant acoustic structure. The system under consideration comprises an oscillatory chain of the axially coupled masses. Each mass of the chain is subject to the local linear potential along the lateral direction and incorporates the lightweight internal rotator. In the present work, we demonstrate the emergence of special resonant regimes of complete bi- and unidirectional transitions between the longitudinal and the shear waves of the locally resonant chain. These regimes are manifested by the two-dimensional energy channeling between the longitudinal and the shear traveling waves in the recurrent as well as the irreversible fashion. We show that the spatial control of the two dimensional energy flow between the longitudinal and the shear waves is solely governed by the motion of the internal rotators. Nonlinear analysis of the regimes of a bidirectional wave channeling unveils their global bifurcation structure and predicts the zones of their spontaneous transitions from a complete bi-directional wave channeling to the one-directional entrapment. An additional regime of a complete irreversible resonant transformation of the longitudinal wave into a shear wave is analyzed in the study. The intrinsic mechanism governing the unidirectional wave reorientation is described analytically. The results of the analysis of both mechanisms are substantiated by the numerical simulations of the full model and are found to be in a good agreement.

  9. Nonviolent Aspects of Interparental Conflict and Dating Violence among Adolescents

    ERIC Educational Resources Information Center

    Tschann, Jeanne M.; Pasch, Lauri A.; Flores, Elena; Marin, Barbara VanOss; Baisch, E. Marco; Wibbelsman, Charles J.

    2009-01-01

    This longitudinal study examined whether nonviolent aspects of interparental conflict, in addition to interparental violence, predicted dating violence perpetration and victimization among 150 Mexican American and European American male and female adolescents, ages 16 to 20. When parents had more frequent conflict, were more verbally aggressive…

  10. Longitudinal Trajectories of Parental Involvement in Type 1 Diabetes and Adolescents’ Adherence

    PubMed Central

    King, Pamela S.; Berg, Cynthia A.; Butner, Jonathan; Butler, Jorie M.; Wiebe, Deborah J.

    2016-01-01

    Objective The purpose of this study was to examine longitudinal trajectories of parental involvement and adolescent adherence to the Type 1 diabetes regimen, to determine whether changes in multiple facets of parental involvement over time predicted subsequent changes in adolescents’ adherence, and to examine whether adolescent self-efficacy mediated the effect of parental involvement on adherence. Method Two hundred fifty-two adolescents (M age = 12.49 years, SD = 1.53; 53.6% females) diagnosed with Type 1 diabetes mellitus, their mothers, and 188 fathers were enrolled in a 2.5-year longitudinal study. Across 5 time points, up to 252 adolescents and their parents completed measures of adherence, parental involvement (diabetes monitoring, behavioral involvement in diabetes management, and acceptance), and adolescent diabetes self-efficacy. Results Using multilevel modeling, analyses indicated significant average declines over time in adherence and most indicators of parental involvement. Lagged multilevel models indicated that declines in mothers’ and fathers’ acceptance and diabetes monitoring predicted subsequent declines in adolescents’ adherence. Additional analyses revealed that longitudinal associations between both maternal acceptance and diabetes monitoring and subsequent adolescent adherence were mediated by adolescents’ self-efficacy. Conclusions Results of this study, which were largely consistent across reporters, highlight the importance of maintaining parental involvement in diabetes across adolescence and suggest that parental involvement is beneficial for adolescents’ adherence, in part, because it contributes to higher self-efficacy for diabetes management among adolescents. PMID:23795709

  11. Penalized maximum likelihood simultaneous longitudinal PET image reconstruction with difference-image priors.

    PubMed

    Ellis, Sam; Reader, Andrew J

    2018-04-26

    Many clinical contexts require the acquisition of multiple positron emission tomography (PET) scans of a single subject, for example, to observe and quantitate changes in functional behaviour in tumors after treatment in oncology. Typically, the datasets from each of these scans are reconstructed individually, without exploiting the similarities between them. We have recently shown that sharing information between longitudinal PET datasets by penalizing voxel-wise differences during image reconstruction can improve reconstructed images by reducing background noise and increasing the contrast-to-noise ratio of high-activity lesions. Here, we present two additional novel longitudinal difference-image priors and evaluate their performance using two-dimesional (2D) simulation studies and a three-dimensional (3D) real dataset case study. We have previously proposed a simultaneous difference-image-based penalized maximum likelihood (PML) longitudinal image reconstruction method that encourages sparse difference images (DS-PML), and in this work we propose two further novel prior terms. The priors are designed to encourage longitudinal images with corresponding differences which have (a) low entropy (DE-PML), and (b) high sparsity in their spatial gradients (DTV-PML). These two new priors and the originally proposed longitudinal prior were applied to 2D-simulated treatment response [ 18 F]fluorodeoxyglucose (FDG) brain tumor datasets and compared to standard maximum likelihood expectation-maximization (MLEM) reconstructions. These 2D simulation studies explored the effects of penalty strengths, tumor behaviour, and interscan coupling on reconstructed images. Finally, a real two-scan longitudinal data series acquired from a head and neck cancer patient was reconstructed with the proposed methods and the results compared to standard reconstruction methods. Using any of the three priors with an appropriate penalty strength produced images with noise levels equivalent to those seen when using standard reconstructions with increased counts levels. In tumor regions, each method produces subtly different results in terms of preservation of tumor quantitation and reconstruction root mean-squared error (RMSE). In particular, in the two-scan simulations, the DE-PML method produced tumor means in close agreement with MLEM reconstructions, while the DTV-PML method produced the lowest errors due to noise reduction within the tumor. Across a range of tumor responses and different numbers of scans, similar results were observed, with DTV-PML producing the lowest errors of the three priors and DE-PML producing the lowest bias. Similar improvements were observed in the reconstructions of the real longitudinal datasets, although imperfect alignment of the two PET images resulted in additional changes in the difference image that affected the performance of the proposed methods. Reconstruction of longitudinal datasets by penalizing difference images between pairs of scans from a data series allows for noise reduction in all reconstructed images. An appropriate choice of penalty term and penalty strength allows for this noise reduction to be achieved while maintaining reconstruction performance in regions of change, either in terms of quantitation of mean intensity via DE-PML, or in terms of tumor RMSE via DTV-PML. Overall, improving the image quality of longitudinal datasets via simultaneous reconstruction has the potential to improve upon currently used methods, allow dose reduction, or reduce scan time while maintaining image quality at current levels. © 2018 The Authors. Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

  12. Modelling variable dropout in randomised controlled trials with longitudinal outcomes: application to the MAGNETIC study.

    PubMed

    Kolamunnage-Dona, Ruwanthi; Powell, Colin; Williamson, Paula Ruth

    2016-04-28

    Clinical trials with longitudinally measured outcomes are often plagued by missing data due to patients withdrawing or dropping out from the trial before completing the measurement schedule. The reasons for dropout are sometimes clearly known and recorded during the trial, but in many instances these reasons are unknown or unclear. Often such reasons for dropout are non-ignorable. However, the standard methods for analysing longitudinal outcome data assume that missingness is non-informative and ignore the reasons for dropout, which could result in a biased comparison between the treatment groups. In this article, as a post hoc analysis, we explore the impact of informative dropout due to competing reasons on the evaluation of treatment effect in the MAGNETIC trial, the largest randomised placebo-controlled study to date comparing the addition of nebulised magnesium sulphate to standard treatment in acute severe asthma in children. We jointly model longitudinal outcome and informative dropout process to incorporate the information regarding the reasons for dropout by treatment group. The effect of nebulised magnesium sulphate compared with standard treatment is evaluated more accurately using a joint longitudinal-competing risk model by taking account of such complexities. The corresponding estimates indicate that the rate of dropout due to good prognosis is about twice as high in the magnesium group compared with standard treatment. We emphasise the importance of identifying reasons for dropout and undertaking an appropriate statistical analysis accounting for such dropout. The joint modelling approach accounting for competing reasons for dropout is proposed as a general approach for evaluating the sensitivity of conclusions to assumptions regarding missing data in clinical trials with longitudinal outcomes. EudraCT number 2007-006227-12 . Registration date 18 Mar 2008.

  13. Association Between Media Use in Adolescence and Depression in Young Adulthood

    PubMed Central

    Primack, Brian A.; Swanier, Brandi; Georgiopoulos, Anna M.; Land, Stephanie R.; Fine, Michael J.

    2010-01-01

    Context Although certain media exposures have been linked to the presence of psychiatric conditions, few studies have investigated the association between media exposure and depression. Objective To assess the longitudinal association between media exposure in adolescence and depression in young adulthood in a nationally representative sample. Design Longitudinal cohort study. Setting and Participants We used the National Longitudinal Survey of Adolescent Health (Add Health) to investigate the relationship between electronic media exposure in 4142 adolescents who were not depressed at baseline and subsequent development of depression after 7 years of follow-up. Main Outcome Measure Depression at follow-up assessed using the 9-item Center for Epidemiologic Studies–Depression Scale. Results Of the 4142 participants (47.5% female and 67.0% white) who were not depressed at baseline and who underwent follow-up assessment, 308 (7.4%) reported symptoms consistent with depression at follow-up. Controlling for all covariates including baseline Center for Epidemiologic Studies–Depression Scale score, those reporting more television use had significantly greater odds of developing depression (odds ratio [95% confidence interval], 1.08 [1.01-1.16]) for each additional hour of daily television use. In addition, those reporting more total media exposure had significantly greater odds of developing depression (1.05 [1.0004-1.10]) for each additional hour of daily use. We did not find a consistent relationship between development of depressive symptoms and exposure to videocassettes, computer games, or radio. Compared with young men, young women were less likely to develop depression given the same total media exposure (odds ratio for interaction term, 0.93 [0.88-0.99]). Conclusion Television exposure and total media exposure in adolescence are associated with increased odds of depressive symptoms in young adulthood, especially in young men. PMID:19188540

  14. Time Outdoors at Specific Ages During Early Childhood and the Risk of Incident Myopia

    PubMed Central

    Shah, Rupal L.; Huang, Yu; Guggenheim, Jeremy A.; Williams, Cathy

    2017-01-01

    Purpose Time outdoors during childhood is negatively associated with incident myopia. Consequently, additional time outdoors has been suggested as a public health intervention to reduce the prevalence of myopia. We investigated whether there were specific ages during early childhood when the time outdoors versus incident myopia association was strongest. Methods Children participating in the Avon Longitudinal Study of Parents and Children (ALSPAC) were studied from age 2 to 15 years. Parentally reported time outdoors and time spent reading were assessed longitudinally in early childhood (ages 2, 3, 4, 5, 7, and 9 years). Noncycloplegic autorefraction was carried out longitudinally in later childhood (ages 10, 11, 12, and 15 years). Information was available for 2833 participants. Cox proportional hazards regression was used to test for association between time outdoors and incident myopia. Results From 3 years of age onward, greater time outdoors was associated with a reduced risk of incident myopia. The hazard ratio for myopia changed progressively from 0.90 (95% CI 0.83–0.98, P = 0.012) at age 3 years, to 0.86 (95% CI 0.78–0.93, P = 0.001) at age 9 years, for each additional SD of time spent outdoors per day. These associations were independent of two major risk factors for myopia: time reading and number of myopic parents. Conclusions Additional time spent outdoors across the 3 to 9 years age range was associated with a reduced incidence of myopia between ages 10 and 15 years. There was a trend for the association to increase toward the older end of the 3 to 9 years range. PMID:28245296

  15. DVH- and NTCP-based dosimetric comparison of different longitudinal margins for VMAT-IMRT of esophageal cancer.

    PubMed

    Münch, S; Oechsner, M; Combs, S E; Habermehl, D

    2017-08-15

    To cover the microscopic tumor spread in squamous cell carcinoma of the esophagus (SCC), longitudinal margins of 3-4 cm are used for radiotherapy (RT) protocols. However, smaller margins of 2-3 cm might be reasonable when advanced diagnostic imaging is integrated into target volume delineation. Purpose of this study was to compare the dose distribution and deposition to the organs at risk (OAR) for different longitudinal margins using a DVH- and NTCP-based approach. Ten patients with SCC of the middle or lower third were retrospectively selected. Three planning target volumes (PTV) with longitudinal margins of 4 cm, 3 cm and 2 cm and an axial margin of 1.5 cm to the gross target volume (GTV) were defined for each patient. For each PTV two treatment plans with total doses of 41.4 Gy (neoadjuvant treatment) and 50.4 Gy (definite treatment) were calculated. Dose to the lungs, heart, myelon and liver were then evaluated and compared between different PTVs. When using a longitudinal margin of 3 cm instead of 4 cm, all dose parameters (Dmin, Dmean, Dmedian and V5-V35), except Dmax could be significantly reduced for the lungs. Regarding the heart, a significant reduction was seen for Dmean and V5, but not for Dmin, Dmax, Dmedian and V10-V35. When comparing a longitudinal margin of 4 cm to a longitudinal margin of 2 cm, a significant difference was calculated for Dmin, Dmean, Dmedian and V5-V35 of the lungs and for Dmax, Dmean and V5-V35 of the heart. Nevertheless, no difference was seen for median heart dose. An additional dose reduction for V10 of the heart was achieved for definite treatment plans when using a longitudinal margin of 3 cm. The NTCP-based risk of pneumonitis was significantly reduced by a margin reduction to 2 cm for neoadjuvant and definite treatment plans. Reduction of longitudinal margins from 4 cm to 3 cm can significantly reduce the dose to lungs and Dmean of the heart. Despite clinical benefit and oncologic outcome remain unclear, reduction of the longitudinal margins might provide the opportunity to reduce side effects of chemoradiation (CRT) for SCC in upcoming studies.

  16. 'TIME': A Web Application for Obtaining Insights into Microbial Ecology Using Longitudinal Microbiome Data.

    PubMed

    Baksi, Krishanu D; Kuntal, Bhusan K; Mande, Sharmila S

    2018-01-01

    Realization of the importance of microbiome studies, coupled with the decreasing sequencing cost, has led to the exponential growth of microbiome data. A number of these microbiome studies have focused on understanding changes in the microbial community over time. Such longitudinal microbiome studies have the potential to offer unique insights pertaining to the microbial social networks as well as their responses to perturbations. In this communication, we introduce a web based framework called 'TIME' (Temporal Insights into Microbial Ecology'), developed specifically to obtain meaningful insights from microbiome time series data. The TIME web-server is designed to accept a wide range of popular formats as input with options to preprocess and filter the data. Multiple samples, defined by a series of longitudinal time points along with their metadata information, can be compared in order to interactively visualize the temporal variations. In addition to standard microbiome data analytics, the web server implements popular time series analysis methods like Dynamic time warping, Granger causality and Dickey Fuller test to generate interactive layouts for facilitating easy biological inferences. Apart from this, a new metric for comparing metagenomic time series data has been introduced to effectively visualize the similarities/differences in the trends of the resident microbial groups. Augmenting the visualizations with the stationarity information pertaining to the microbial groups is utilized to predict the microbial competition as well as community structure. Additionally, the 'causality graph analysis' module incorporated in TIME allows predicting taxa that might have a higher influence on community structure in different conditions. TIME also allows users to easily identify potential taxonomic markers from a longitudinal microbiome analysis. We illustrate the utility of the web-server features on a few published time series microbiome data and demonstrate the ease with which it can be used to perform complex analysis.

  17. Maternal support following childhood sexual abuse: Associations with children's adjustment post-disclosure and at 9-month follow-up.

    PubMed

    Zajac, Kristyn; Ralston, M Elizabeth; Smith, Daniel W

    2015-06-01

    Maternal support has been widely cited as an important predictor of children's adjustment following disclosure of sexual abuse. However, few studies have examined these effects longitudinally. The current study examines the relationships between a multidimensional assessment of maternal support rated by both mothers and children and children's adjustment in various domains (internalizing, externalizing, anger, depression, and posttraumatic stress disorder symptoms) concurrently and longitudinally. Participants were 118 mother-child dyads recruited from a Child Advocacy Center where children were determined through a forensic evaluation to be victims of sexual abuse. Child and mother ratings of maternal support and child adjustment were collected shortly after the forensic evaluation and at 9-month follow-up. Results were consistent with findings from past studies that maternal support is significantly related to children's post-disclosure adjustment and extends these findings longitudinally. Additionally, the study sheds light on differential relations between dimensions of maternal support (Emotional Support, Blame/Doubt, Vengeful Arousal, and Skeptical Preoccupation) and child adjustment and suggests the importance of using both child and mother ratings of maternal support in future research. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. The Rising Prevalence of Autism: A Prospective Longitudinal Study in the Faroe Islands

    ERIC Educational Resources Information Center

    Kocovska, Eva; Biskupsto, Rannva; Gillberg, I. Carina; Ellefsen, Asa; Kampmann, Hanna; Stora, Tormoour; Billstedt, Eva; Gillberg, Christopher

    2012-01-01

    We have followed up a 2002 population study of autism prevalence in 15-24-year olds in the Faroe Islands. The rate of ASD grew significantly from 0.56% in 2002 to 0.94% in 2009. Although these results are within the range of typical findings from other studies, there were some interesting details. There were--in addition to 43 originally diagnosed…

  19. A Longitudinal Study in Adults with Sequential Bilateral Cochlear Implants: Time Course for Individual Ear and Bilateral Performance

    ERIC Educational Resources Information Center

    Reeder, Ruth M.; Firszt, Jill B.; Holden, Laura K.; Strube, Michael J.

    2014-01-01

    Purpose: The purpose of this study was to examine the rate of progress in the 2nd implanted ear as it relates to the 1st implanted ear and to bilateral performance in adult sequential cochlear implant recipients. In addition, this study aimed to identify factors that contribute to patient outcomes. Method: The authors performed a prospective…

  20. Predictive Effects of Social Anxiety on Increases in Future Peer Victimization for a Community Sample of Middle-School Youth

    ERIC Educational Resources Information Center

    Mulder, Saskia F.; Hutteman, Roos; van Aken, Marcel A. G.

    2017-01-01

    This longitudinal study focused on clarifying the direction of effects between social anxiety and victimization in a community-based sample. In addition, we studied the moderating effect of gender on this association. A total of 1,649 children (45% boys, approximately 12 years old) of 65 secondary-school classes participated in the study.…

  1. Predicting Disease Progression in Scleroderma with Skin and Blood Biomarkers

    DTIC Science & Technology

    2016-12-01

    epidermal differentiation in addition to those involved in extracel- lular matrix production and myofibroblast contractility (35). In a followup study ...important manifestation of SSc are needed. Several studies have linked autoantibody production with genetics in SSc. Multiple polymorphisms in the human...longitudinal clinical data and genetic markers. GENISOS is an inception cohort that avoids survival bias inherent in studies of prevalent cases (mean disease

  2. The Invisible Student: A Longitudinal Study of the Beginning Freshman Class of 1963 at the University of New Mexico.

    ERIC Educational Resources Information Center

    Winther, Sven F.; And Others

    The 1963 Freshman class at the University of New Mexico was studied through June, 1968, for performance patterns in relation to overall performance, high school grade-point average, male-female, Spanish surnames and non-Spanish surnames. In addition to university furnished data, questionnaires were submitted to a stratified random sample of…

  3. Multiple Goals in a Hong Kong Chinese Educational Context: An Investigation of Developmental Trends and Learning Outcomes

    ERIC Educational Resources Information Center

    Watkins, David; Hattie, John

    2012-01-01

    Social goals have also been proposed as important additions to mastery and performance goals in educational contexts, particularly in non-Western cultures but no study has yet tested the possibility that such goals can also combine with mastery and performance goals leading to superior learning outcomes. Longitudinal studies are also rare in this…

  4. Coping with Relationship Stressors: The Impact of Different Working Models of Attachment and Links to Adaptation

    ERIC Educational Resources Information Center

    Seiffge-Krenke, Inge

    2006-01-01

    The study explores the role of working models of attachment in the process of coping with relationship stressors with a focus on long-term adaptation. In a 7-year longitudinal study of 112 participants, stress and coping were assessed during adolescence and emerging adulthood. In addition, working models of attachment were assessed by employing…

  5. Neuropsychiatric and cardiometabolic comorbidities in patients with previously diagnosed Cushing's disease: a longitudinal observational study

    PubMed Central

    Dimopoulou, C; Geraedts, V; Stalla, G K; Sievers, C

    2015-01-01

    Introduction Only few studies have systematically investigated neuropsychiatric aspects in patients with Cushing's disease (CD). Pain syndromes have been described in patients with pituitary adenomas, but so far no systematical investigation has been conducted in patients with CD. Additionally, CD has an association with cardiometabolic comorbidities which ultimately leads to increased morbidity and mortality. Long-term treatment of the hypercortisolic state cannot prevent the persistence of an unfavourable cardiometabolic risk profile. Finally, chronic hypercortisolism is known to impact the health-related quality of life (HRQoL). We aim to systematically investigate the neuropsychiatric and cardiometabolic comorbidities, as well as assess the HRQoL, in patients with previously diagnosed CD in a longitudinal fashion. Methods and analysis In this longitudinal study, we will assess 20 patients with CD displaying biochemical control 24 months after recruitment in the initial cross-sectional study (n=80). This will be a mixed cohort including patients after surgical, after radiation therapy and/or under current medical treatment for CD. Primary outcomes include changes in mean urinary free cortisol and changes in specific pain patterns. Secondary/exploratory neuropsychiatric domains include depression, anxiety, personality, sleep, body image and quality of life. Secondary/exploratory cardiometabolic domains include anthropometric parameters, cardiometabolic risk biomarkers and insulin resistance. Additional domains will be investigated if warranted by clinical indication. Safety assessment under medical therapy will include liver enzymes, ECG abnormalities and hyperglycaemia. Ethics and dissemination Risk of damage from study-conditioned measures is very small and considered ethically justified. Dual-energy X-ray absorptiometry may call for detailed fracture risk assessment. However, the radiation dose is very small and only administered on clinical indication; therefore, it is considered ethically justified. This protocol has been approved by the local medical ethics committee. PMID:25818269

  6. Quantitative genetic analysis of cellular adhesion molecules: the Fels Longitudinal Study.

    PubMed

    Lee, Miryoung; Czerwinski, Stefan A; Choh, Audrey C; Demerath, Ellen W; Sun, Shumei S; Chumlea, Wm C; Towne, Bradford; Siervogel, Roger M

    2006-03-01

    Circulating concentrations of inflammatory markers predict cardiovascular disease (CVD) risk and are closely associated with obesity. However, little is known concerning genetic influences on serum levels of inflammatory markers. In this study, we estimated the heritability (h2) of soluble cellular adhesion molecule (sCAM) concentrations and examined the correlational architecture between different sCAMs. The study population included 234 men and 270 women aged 18-76 years, belonging to 121 families participating in the Fels Longitudinal Study. Serum levels of soluble intercellular adhesion molecule-1 (sICAM-1), vascular cell adhesion molecule-1 (sVCAM-1), E-selectin (sESEL-1) and P-selectin (sPSEL-1) were assayed using commercially available kits. A variance components-based maximum likelihood method was used to estimate the h2 of the different serum inflammatory markers while simultaneously adjusting for the effects of known CVD risk factors, such as age and smoking. Additionally, we used bivariate extensions of these methods to estimate genetic and random environmental correlations among sCAMs. Levels of sCAMs were significantly heritable: h2=0.24+/-0.10 for sICAM-1, h2=0.22+/-0.10 for sVCAM-1, h2=0.50+/-0.11 for sESEL-1, and h2=0.46+/-0.10 for sPSEL-1. In addition, a significant genetic correlation (rho(G)=0.63) was found between sICAM-1 and sVCAM-1 indicating some degree of shared genetic control. In the Fels Longitudinal Study, the levels of four sCAMs are significantly influenced by genetic effects, and sICAM-1 shares a common genetic background with sVCAM-1.

  7. A Guide to Using State Longitudinal Data for Applied Research. NCEE 2015-4013

    ERIC Educational Resources Information Center

    Levesque, Karen; Fitzgerald, Robert; Pfeiffer, Jay

    2015-01-01

    State longitudinal data systems (SLDSs) promise a rich source of data for education research. SLDSs contain statewide student data that can be linked over time and to additional data sources for education management, reporting, improvement, and research, and ultimately for informing education policy and practice. Authored by Karen Levesque, Robert…

  8. Developments with the Commission's Longitudinal Student Data System. Working Paper WP/06-07

    ERIC Educational Resources Information Center

    California Postsecondary Education Commission, 2006

    2006-01-01

    This paper summarizes the many uses of the California Postsecondary Education Commission's data system and describes work in progress on adding additional data elements. It describes how the Commission is using its Longitudinal Student Data System (LSDS) to examine the movement of students through California's public colleges and universities. The…

  9. Longitudinal Relationships of Fitness, Physical Activity, and Weight Status with Academic Achievement in Adolescents

    ERIC Educational Resources Information Center

    Suchert, Vivien; Hanewinkel, Reiner; Isensee, Barbara

    2016-01-01

    Background: To examine associations of cardiorespiratory fitness, physical activity (PA) and weight status with academic achievement 1 year later. In addition, the mediating role of psychological variables was tested. Methods: Longitudinal analyses included 1011 German students (M = 14.1 years, SD = 0.6 years). Cardiorespiratory fitness was…

  10. Structural equation models of VMT growth in US urbanised areas.

    USGS Publications Warehouse

    Ewing, Reid; Hamidi, Shima; Gallivan, Frank; Nelson, Arthur C.; Grace, James B.

    2014-01-01

    Vehicle miles travelled (VMT) is a primary performance indicator for land use and transportation, bringing with it both positive and negative externalities. This study updates and refines previous work on VMT in urbanised areas, using recent data, additional metrics and structural equation modelling (SEM). In a cross-sectional model for 2010, population, income and freeway capacity are positively related to VMT, while gasoline prices, development density and transit service levels are negatively related. Findings of the cross-sectional model are generally confirmed in a more tightly controlled longitudinal study of changes in VMT between 2000 and 2010, the first model of its kind. The cross-sectional and longitudinal models together, plus the transportation literature generally, give us a basis for generalising across studies to arrive at elasticity values of VMT with respect to different urban variables.

  11. Does Preschool Self-Regulation Predict Later Behavior Problems in General or Specific Problem Behaviors?

    PubMed

    Lonigan, Christopher J; Spiegel, Jamie A; Goodrich, J Marc; Morris, Brittany M; Osborne, Colleen M; Lerner, Matthew D; Phillips, Beth M

    2017-11-01

    Findings from prior research have consistently indicated significant associations between self-regulation and externalizing behaviors. Significant associations have also been reported between children's language skills and both externalizing behaviors and self-regulation. Few studies to date, however, have examined these relations longitudinally, simultaneously, or with respect to unique clusters of externalizing problems. The current study examined the influence of preschool self-regulation on general and specific externalizing behavior problems in early elementary school and whether these relations were independent of associations between language, self-regulation, and externalizing behaviors in a sample of 815 children (44% female). Additionally, given a general pattern of sex differences in the presentations of externalizing behavior problems, self-regulation, and language skills, sex differences for these associations were examined. Results indicated unique relations of preschool self-regulation and language with both general externalizing behavior problems and specific problems of inattention. In general, self-regulation was a stronger longitudinal correlate of externalizing behavior for boys than it was for girls, and language was a stronger longitudinal predictor of hyperactive/impulsive behavior for girls than it was for boys.

  12. Co-occurrences between adolescent substance use and academic performance: school context influences a multilevel-longitudinal perspective.

    PubMed

    Andrade, Fernando H

    2014-08-01

    A growing body of literature has linked substance use and academic performance exploring substance use as a predictor of academic performance or vice versa. This study uses a different approach conceptualizing substance use and academic performance as parallel outcomes and exploring two topics: its multilevel-longitudinal association and school contextual effects on both outcomes. Using multilevel Confirmatory Factor Analysis and multilevel-longitudinal analyses, the empirical estimates relied on 7843 students nested in 114 schools (Add Health study). The main finding suggests that the correlation between substance use and academic performance was positive at the school level in contraposition to the negative relationship at the individual level. Additional findings suggest a positive effect of a school risk factor on substance use and a positive effect of academic pressure on academic performance. These findings represent a contribution to our understanding of how schools could affect the relationship between academic performance and substance use. Copyright © 2014 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

  13. An analytical study and wind tunnel tests of an aeromechanical gust-alleviation system for a light airplane

    NASA Technical Reports Server (NTRS)

    Stewart, E. C.

    1976-01-01

    The results of an analytical study of a system using stability derivatives determined in static wind tunnel tests of a 1/6 scale model of a popular, high wing, light airplane equipped with the gust alleviation system are reported. The longitudinal short period mode dynamics of the system are analyzed, and include the following: (1) root loci, (2) airplane frequency responses to vertical gusts, (3) power spectra of the airplane responses in a gust spectrum, (4) time history responses to vertical gusts, and (5) handling characteristics. The system reduces the airplane's normal acceleration response to vertical gusts while simultaneously increasing the pitching response and reducing the damping of the longitudinal short period mode. The normal acceleration response can be minimized by using the proper amount of static alleviation and a fast response system with a moderate amount of damping. The addition of a flap elevator interconnect or a pitch damper system further increases the alleviation while moderating the simultaneous increase in pitching response. The system provides direct lift control and may reduce the stick fixed longitudinal static stability.

  14. The Effects of Extensive Reading and Reading Strategies on Reading Self-Efficacy

    ERIC Educational Resources Information Center

    Burrows, Lance

    2012-01-01

    This study is a quasi-experimental, longitudinal investigation into the role that extensive reading and reading strategies play in the cultivation of reading self-efficacy. Conducted over the course of one academic year, how changes in reading self-efficacy translate into changes in reading comprehension was examined. In addition, the…

  15. Social Support, Unfulfilled Expectations, and Affective Well-Being on Return to Employment

    ERIC Educational Resources Information Center

    Seiger, Christine P.; Wiese, Bettina S.

    2011-01-01

    We conducted a longitudinal study to investigate how social support from the partner is related to mothers' affective well-being during their return to employment after maternity leave and whether expectations of that support have an additional impact. We differentiated four forms of support and their respective expectation discrepancies:…

  16. Mexican American Adolescents' Profiles of Risk and Mental Health: A Person-Centered Longitudinal Approach

    ERIC Educational Resources Information Center

    Zeiders, Katharine H.; Roosa, Mark W.; Knight, George P.; Gonzales, Nancy A.

    2013-01-01

    Although Mexican American adolescents experience multiple risk factors in their daily lives, most research examines the influences of risk factors on adjustment independently, ignoring the additive and interactive effects of multiple risk factors. Guided by a person-centered perspective and utilizing latent profile analysis, this study identified…

  17. Bilingual Education in a Community Language: Lessons from a Longitudinal Study

    ERIC Educational Resources Information Center

    Molyneux, Paul; Scull, Janet; Aliani, Renata

    2016-01-01

    Provision for students learning English as an additional language (EAL) frequently overlooks the linguistic resources these children bring to the classroom. This is despite international research that highlights the facilitative links between support of the home language and the acquisition of new languages. This article reports on a longitudinal…

  18. The Development of Executive Function and Language Skills in the Early School Years

    ERIC Educational Resources Information Center

    Gooch, Debbie; Thompson, Paul; Nash, Hannah M.; Snowling, Margaret J.; Hulme, Charles

    2016-01-01

    Background: The developmental relationships between executive functions (EF) and early language skills are unclear. This study explores the longitudinal relationships between children's early EF and language skills in a sample of children with a wide range of language abilities including children at risk of dyslexia. In addition, we investigated…

  19. Longitudinal Analysis of Receptive Vocabulary Growth in Young Spanish English-Speaking Children from Migrant Families

    ERIC Educational Resources Information Center

    Jackson, Carla Wood; Schatschneider, Christopher; Leacox, Lindsey

    2014-01-01

    Purpose: The authors of this study described developmental trajectories and predicted kindergarten performance of Spanish and English receptive vocabulary acquisition of young Latino/a English language learners (ELLs) from socioeconomically disadvantaged migrant families. In addition, the authors examined the extent to which gender and individual…

  20. Predictors of Post-School Success: A Systematic Review of NLTS2 Secondary Analyses

    ERIC Educational Resources Information Center

    Mazzotti, Valerie L.; Rowe, Dawn A.; Sinclair, James; Poppen, Marcus; Woods, William E.; Shearer, Mackenzie L.

    2016-01-01

    The purpose of this systematic review was to (a) systematically review the literature to identify National Longitudinal Transition Study-2 secondary analyses articles published since 2009 that met the quality indicators for correlational research, (b) further extend the findings of Test et al. by identifying additional evidence to support the…

  1. Longitudinal Examination of PTSD Symptoms and Problematic Alcohol Use as Risk Factors for Adolescent Victimization

    ERIC Educational Resources Information Center

    McCart, Michael R.; Zajac, Kristyn; Kofler, Michael J.; Smith, Daniel W.; Saunders, Benjamin E.; Kilpatrick, Dean G.

    2012-01-01

    The current study examined associations between posttraumatic stress disorder (PTSD) symptoms and future interpersonal victimization among adolescents, after accounting for the impact of early victimization exposure, gender, ethnicity, and household income. In addition, problematic alcohol use was tested as a mediator of the relation between PTSD…

  2. Longitudinal Comparison of Place-Value and Arithmetic Knowledge in Montessori and Non-Montessori Students

    ERIC Educational Resources Information Center

    Laski, Elida V.; Vasilyeva, Marina; Schiffman, Joanna

    2016-01-01

    Understanding of base 10 and place value are important foundational math concepts that are associated with higher use of decomposition strategies and higher accuracy on addition problems (Laski, Ermakova, & Vasilyeva, 2014; Fuson, 1990; Fuson & Briars, 1990; National Research Council, 2001). The current study examined base-10 knowledge,…

  3. Longitudinal Associations of Alcohol Involvement with Subjective Well-Being in Adolescence and Prediction to Alcohol Problems in Early Adulthood

    ERIC Educational Resources Information Center

    Mason, W. Alex; Spoth, Richard L.

    2011-01-01

    Adolescent alcohol involvement is associated with numerous negative outcomes, but also appears to have positive correlates, including subjective well-being. Additional research is needed to understand these paradoxical findings. The current study examines alcohol use, adverse alcohol-related (and other substance-related) consequences, and…

  4. Identification and Prediction of Drinking Trajectories in Early and Mid-Adolescence

    ERIC Educational Resources Information Center

    Van Der Vorst, Haske; Vermulst, Ad A.; Meeus, Wim H. J.; Dekovic, Maja; Engels, Rutger C. M. E.

    2009-01-01

    The aim of this study was to identify subgroups of early and mid-adolescents with different drinking trajectories. In addition, we examined whether gender, parental, and peer factors predicted adolescents' membership of these drinking trajectories. We used longitudinal data of 428 families (fathers, mothers, mid-adolescents, and their younger…

  5. Associations in the longitudinal course of body dysmorphic disorder with major depression, obsessive-compulsive disorder, and social phobia.

    PubMed

    Phillips, Katharine A; Stout, Robert L

    2006-06-01

    Body dysmorphic disorder (BDD) is an impairing and relatively common disorder that has high comorbidity with certain Axis I disorders. However, the longitudinal associations between BDD and comorbid disorders have not previously been examined. Such information may shed light on the nature of BDD's relationship to putative "near-neighbor" disorders, such as major depression, obsessive-compulsive disorder (OCD), and social phobia. This study examined time-varying associations between BDD and these comorbid disorders in 161 participants over 1-3 years of follow-up in the first prospective longitudinal study of the course of BDD. We found that BDD had significant longitudinal associations with major depression--that is, change in the status of BDD and major depression was closely linked in time, with improvement in major depression predicting BDD remission, and, conversely, improvement in BDD predicting depression remission. We also found that improvement in OCD predicted BDD remission, but that BDD improvement did not predict OCD remission. No significant longitudinal associations were found for BDD and social phobia (although the results for analyses of OCD and social phobia were less numerically stable). These findings suggest (but do not prove) that BDD may be etiologically linked to major depression and OCD, i.e., that BDD may be a member of both the putative OCD spectrum and the affective spectrum. However, BDD does not appear to simply be a symptom of these comorbid disorders, as BDD symptoms persisted in a sizable proportion of subjects who remitted from these comorbid disorders. Additional studies are needed to elucidate the nature of BDD's relationship to commonly co-occurring disorders, as this issue has important theoretical and clinical implications.

  6. Age- and Sex-Related Influences on Left Ventricular Mechanics in Elderly Individuals Free of Prevalent Heart Failure: The ARIC Study (Atherosclerosis Risk in Communities).

    PubMed

    Hung, Chung-Lieh; Gonçalves, Alexandra; Shah, Amil M; Cheng, Susan; Kitzman, Dalane; Solomon, Scott D

    2017-01-01

    Advanced age is related to left ventricular (LV) remodeling. We sought to investigate the relationships between aging, elevated hemodynamic load, cardiac mechanics, and LV remodeling in an elderly community-based population. We studied 1105 subjects (76±5 years, 61% women) without prevalent heart failure, who attended the visit 5 of the ARIC study (Atherosclerosis Risk in Communities). LV global longitudinal strain, global circumferential strain, and torsion indices were analyzed using 3-dimensional echocardiography. Advanced age was associated with greater LV concentricity, lower myocardial diastolic relaxation, reduced global longitudinal strain (adjusted estimate, 0.39±0.19% (SE)/decade; P=0.038), borderline greater global circumferential strain (adjusted estimate, -0.59±0.36% (SE)/decade; P=0.08), and higher torsion indices (adjusted estimate for torsion, 0.33±0.04° (SE)/decade; P<0.001). In addition, greater concentricity was associated with decreased global longitudinal strain and greater torsion in multivariable models (all P<0.001). Women showed smaller LV cavity size, greater concentricity, lower myocardial relaxation velocity E', though demonstrated greater global longitudinal strain, global circumferential strain, and torsion than men (all P<0.05). Overall, subjects with hypertension and increasing age were more likely to have higher torsion, though the association between advanced age and greater torsion was more pronounced in women than in men (both interaction P<0.05). In an asymptomatic, senescent community-dwelling population, we observed a distinct, sex-specific pattern of cardiac remodeling. Although we observed worse diastolic and longitudinal function with advanced age or elevated load in both sexes, a significant increase of torsion was more pronounced in women. © 2017 American Heart Association, Inc.

  7. Associations in the Longitudinal Course of Body Dysmorphic Disorder with Major Depression, Obsessive Compulsive Disorder, and Social Phobia

    PubMed Central

    Phillips, Katharine A.; Stout, Robert L.

    2009-01-01

    Body dysmorphic disorder (BDD) is an impairing and relatively common disorder that has high comorbidity with certain Axis I disorders. However, the longitudinal associations between BDD and comorbid disorders have not previously been examined. Such information may shed light on the nature of BDD’s relationship to putative “near-neighbor” disorders, such as major depression, obsessive-compulsive disorder (OCD), and social phobia. This study examined time-varying associations between BDD and these comorbid disorders in 161 participants over 1 to 3 years of follow-up in the first prospective longitudinal study of the course of BDD. We found that BDD had significant longitudinal associations with major depression – that is, change in the status of BDD and major depression were closely linked in time, with improvement in major depression predicting BDD remission, and, conversely, improvement in BDD predicting depression remission. We also found that improvement in OCD predicted BDD remission, but that BDD improvement did not predict OCD remission. No significant longitudinal associations were found for BDD and social phobia (although the results for analyses of OCD and social phobia were less numerically stable). These findings suggest (but do not prove) that BDD may be etiologically linked to major depression and OCD – i.e., that BDD may be a member of both the putative OCD spectrum and the affective spectrum. However, BDD does not appear to simply be a symptom of these comorbid disorders, as BDD symptoms persisted in a sizable proportion of subjects who remitted from these comorbid disorders. Additional studies are needed to elucidate the nature of BDD’s relationship to commonly co-occurring disorders, as this issue has important theoretical and clinical implications. PMID:16309706

  8. The comorbidity of anxiety and depressive symptoms in older adults with attention-deficit/hyperactivity disorder: a longitudinal study.

    PubMed

    Michielsen, Marieke; Comijs, Hannie C; Semeijn, Evert J; Beekman, Aartjan T F; Deeg, Dorly J H; Sandra Kooij, J J

    2013-06-01

    Comorbidity between Attention-Deficit/Hyperactivity Disorder (ADHD) and depression and anxiety disorders in children and young to middle-aged adults has been well documented in the literature. Yet, it is still unknown whether this comorbidity persists into later life. The aim of this study is therefore to examine the comorbidity of anxiety and depressive symptoms among older adults with ADHD. This is examined both using cross-sectional and longitudinal data. Data were used from the Longitudinal Aging Study Amsterdam (LASA). Participants were examined in three measurement cycles, covering six years. They were asked about depressive and anxiety symptoms. To diagnose ADHD, the DIVA 2.0, a diagnostic interview was administered among a subsample (N=231, age 60-94). In addition to the ADHD diagnosis, the association between the sum score of ADHD symptoms and anxiety and depressive symptoms was examined. Data were analyzed by means of linear regression analyses and linear mixed models. Both ADHD diagnosis and more ADHD symptoms were associated with more anxiety and depressive symptoms cross-sectionally as well as longitudinally. The longitudinal analyses showed that respondents with higher scores of ADHD symptoms reported an increase of depressive symptoms over six years whereas respondents with fewer ADHD symptoms remained stable. The ADHD diagnosis is based on the DSM-IVcriteria, which were developed for children, and have not yet been validated in (older) adults. It appears that the association between ADHD and anxiety/depression remains in place with aging. This suggests that, in clinical practice, directing attention to both in concert may be fruitful. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. How do veterinary students' motivation and study practices relate to academic success?

    PubMed

    Mikkonen, Johanna; Ruohoniemi, Mirja

    2011-01-01

    The aim of the present study was to explore the factors associated with veterinary students' study success. All veterinary students who began their studies at the University of Helsinki in 2005 participated in this qualitative longitudinal study (N=52). The data consisted of assignments that the students completed at the beginning of their studies and again after three years of studying. The focus was on differences in motivation and study practices as well as possible changes in these over the three-year period. The students were divided into three groups according to their study success (grade point average and study progress). These groups were compared according to group-level differences in the categorized data. The most successful students already described themselves using more positive words than other students at the beginning of their veterinary studies. In addition, they seemed more adaptive in relation to the study's demands. However, there were drops in both the most and least successful students' motivation during their studies. The findings suggest that it is possible to predict forthcoming study problems by analyzing students' study practices and their own descriptions of themselves as learners. In addition, the results show that veterinary students' high motivation cannot be taken for granted. The comparative and longitudinal perspective of the present study can be useful in the development of curricula and in student support.

  10. A longitudinal study of an intervention to improve road safety climate: climate as an organizational boundary spanner.

    PubMed

    Naveh, Eitan; Katz-Navon, Tal

    2015-01-01

    This study presents and tests an intervention to enhance organizational climate and expands existing conceptualization of organizational climate to include its influence on employee behaviors outside the organization's physical boundaries. In addition, by integrating the literatures of climate and work-family interface, the study explored climate spillover and crossover from work to the home domain. Focusing on an applied practical problem within organizations, we investigated the example of road safety climate and employees' and their families' driving, using a longitudinal study design of road safety intervention versus control groups. Results demonstrated that the intervention increased road safety climate and decreased the number of traffic violation tickets and that road safety climate mediated the relationship between the intervention and the number of traffic violation tickets. Road safety climate spilled over to the family domain but did not cross over to influence family members' driving. (c) 2015 APA, all rights reserved.

  11. Participation in an Intensive Longitudinal Study with Weekly Web Surveys Over 2.5 Years

    PubMed Central

    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 pregnancy-related behaviors also had lower levels of study attrition, and completed more interviews overall, than did their counterparts. Conclusions We found that measures of participation in a longitudinal study with weekly web surveys varied not only by respondent characteristics, but also by behaviors measured across the surveys. Our analyses suggest that respondents who experience the behaviors measured by the study may maintain higher participation levels than respondents who do not experience those behaviors. PMID:27338859

  12. A Transonic Wind-Tunnel Investigation of the Longitudinal Aerodynamic Characteristics of a Model of the Lockheed XF-104 Airplane

    NASA Technical Reports Server (NTRS)

    Hieser, Gerald; Reid, Charles F.

    1954-01-01

    The transonic longitudinal aerodynamic characteristics of a 0.0858-scale model of the Lockheed XF-104 airplane have been obtained from tests at the Langley 16-foot transonic tunnel. The results of the investigation provide some general information applicable to the transonic properties of thin, low-aspect-ratio, unswept wing configurations utilizing a high horizontal tail . The model employs a horizontal tail mounted at the top of the vertical tail and a wing with an aspect ratio of 2.5, a taper ratio of 0.385, and 3.4-percent-thick airfoil sections. The lift, drag, and static longitudinal pitching moment were measured at Mach numbers from 0.80 t o 1.09 and angles of attack from -2.5 deg to 22.5 deg. Some of the dynamic longitudinal stability properties of the airplane have been predicted from the test results. In addition, some visual flow studies on the wing surfaces obtained at Mach numbers of 0.80 and 1.00 are included. Results of the investigation show that the transonic rise in drag coefficient at zero lift is about 0.030. At high angles of attack, the model becomes longitudinally unstable at Mach numbers from 0.80 t o 0.90, whereas a reduction in static stability is experienced when very high angles of attack are reached at Mach numbers above 0.90. Longitudinal dynamic stability calculations show that the longitudinal control is good at angles of attack below the unstable break in the static pitching-moment curves, but a typical corrective control applied after the occurrence of neutral stability has little effect in averting pitch-up.

  13. On the Use of Diversity Measures in Longitudinal Sequencing Studies of Microbial Communities.

    PubMed

    Wagner, Brandie D; Grunwald, Gary K; Zerbe, Gary O; Mikulich-Gilbertson, Susan K; Robertson, Charles E; Zemanick, Edith T; Harris, J Kirk

    2018-01-01

    Identification of the majority of organisms present in human-associated microbial communities is feasible with the advent of high throughput sequencing technology. As substantial variability in microbiota communities is seen across subjects, the use of longitudinal study designs is important to better understand variation of the microbiome within individual subjects. Complex study designs with longitudinal sample collection require analytic approaches to account for this additional source of variability. A common approach to assessing community changes is to evaluate the change in alpha diversity (the variety and abundance of organisms in a community) over time. However, there are several commonly used alpha diversity measures and the use of different measures can result in different estimates of magnitude of change and different inferences. It has recently been proposed that diversity profile curves are useful for clarifying these differences, and may provide a more complete picture of the community structure. However, it is unclear how to utilize these curves when interest is in evaluating changes in community structure over time. We propose the use of a bi-exponential function in a longitudinal model that accounts for repeated measures on each subject to compare diversity profiles over time. Furthermore, it is possible that no change in alpha diversity (single community/sample) may be observed despite the presence of a highly divergent community composition. Thus, it is also important to use a beta diversity measure (similarity between multiple communities/samples) that captures changes in community composition. Ecological methods developed to evaluate temporal turnover have currently only been applied to investigate changes of a single community over time. We illustrate the extension of this approach to multiple communities of interest (i.e., subjects) by modeling the beta diversity measure over time. With this approach, a rate of change in community composition is estimated. There is a need for the extension and development of analytic methods for longitudinal microbiota studies. In this paper, we discuss different approaches to model alpha and beta diversity indices in longitudinal microbiota studies and provide both a review of current approaches and a proposal for new methods.

  14. On the Use of Diversity Measures in Longitudinal Sequencing Studies of Microbial Communities

    PubMed Central

    Wagner, Brandie D.; Grunwald, Gary K.; Zerbe, Gary O.; Mikulich-Gilbertson, Susan K.; Robertson, Charles E.; Zemanick, Edith T.; Harris, J. Kirk

    2018-01-01

    Identification of the majority of organisms present in human-associated microbial communities is feasible with the advent of high throughput sequencing technology. As substantial variability in microbiota communities is seen across subjects, the use of longitudinal study designs is important to better understand variation of the microbiome within individual subjects. Complex study designs with longitudinal sample collection require analytic approaches to account for this additional source of variability. A common approach to assessing community changes is to evaluate the change in alpha diversity (the variety and abundance of organisms in a community) over time. However, there are several commonly used alpha diversity measures and the use of different measures can result in different estimates of magnitude of change and different inferences. It has recently been proposed that diversity profile curves are useful for clarifying these differences, and may provide a more complete picture of the community structure. However, it is unclear how to utilize these curves when interest is in evaluating changes in community structure over time. We propose the use of a bi-exponential function in a longitudinal model that accounts for repeated measures on each subject to compare diversity profiles over time. Furthermore, it is possible that no change in alpha diversity (single community/sample) may be observed despite the presence of a highly divergent community composition. Thus, it is also important to use a beta diversity measure (similarity between multiple communities/samples) that captures changes in community composition. Ecological methods developed to evaluate temporal turnover have currently only been applied to investigate changes of a single community over time. We illustrate the extension of this approach to multiple communities of interest (i.e., subjects) by modeling the beta diversity measure over time. With this approach, a rate of change in community composition is estimated. There is a need for the extension and development of analytic methods for longitudinal microbiota studies. In this paper, we discuss different approaches to model alpha and beta diversity indices in longitudinal microbiota studies and provide both a review of current approaches and a proposal for new methods. PMID:29872428

  15. Measurement error, time lag, unmeasured confounding: Considerations for longitudinal estimation of the effect of a mediator in randomised clinical trials.

    PubMed

    Goldsmith, K A; Chalder, T; White, P D; Sharpe, M; Pickles, A

    2018-06-01

    Clinical trials are expensive and time-consuming and so should also be used to study how treatments work, allowing for the evaluation of theoretical treatment models and refinement and improvement of treatments. These treatment processes can be studied using mediation analysis. Randomised treatment makes some of the assumptions of mediation models plausible, but the mediator-outcome relationship could remain subject to bias. In addition, mediation is assumed to be a temporally ordered longitudinal process, but estimation in most mediation studies to date has been cross-sectional and unable to explore this assumption. This study used longitudinal structural equation modelling of mediator and outcome measurements from the PACE trial of rehabilitative treatments for chronic fatigue syndrome (ISRCTN 54285094) to address these issues. In particular, autoregressive and simplex models were used to study measurement error in the mediator, different time lags in the mediator-outcome relationship, unmeasured confounding of the mediator and outcome, and the assumption of a constant mediator-outcome relationship over time. Results showed that allowing for measurement error and unmeasured confounding were important. Contemporaneous rather than lagged mediator-outcome effects were more consistent with the data, possibly due to the wide spacing of measurements. Assuming a constant mediator-outcome relationship over time increased precision.

  16. Measurement error, time lag, unmeasured confounding: Considerations for longitudinal estimation of the effect of a mediator in randomised clinical trials

    PubMed Central

    Goldsmith, KA; Chalder, T; White, PD; Sharpe, M; Pickles, A

    2016-01-01

    Clinical trials are expensive and time-consuming and so should also be used to study how treatments work, allowing for the evaluation of theoretical treatment models and refinement and improvement of treatments. These treatment processes can be studied using mediation analysis. Randomised treatment makes some of the assumptions of mediation models plausible, but the mediator–outcome relationship could remain subject to bias. In addition, mediation is assumed to be a temporally ordered longitudinal process, but estimation in most mediation studies to date has been cross-sectional and unable to explore this assumption. This study used longitudinal structural equation modelling of mediator and outcome measurements from the PACE trial of rehabilitative treatments for chronic fatigue syndrome (ISRCTN 54285094) to address these issues. In particular, autoregressive and simplex models were used to study measurement error in the mediator, different time lags in the mediator–outcome relationship, unmeasured confounding of the mediator and outcome, and the assumption of a constant mediator–outcome relationship over time. Results showed that allowing for measurement error and unmeasured confounding were important. Contemporaneous rather than lagged mediator–outcome effects were more consistent with the data, possibly due to the wide spacing of measurements. Assuming a constant mediator–outcome relationship over time increased precision. PMID:27647810

  17. Stiffness and Poisson ratio in longitudinal compression of fiber yarns in meso-FE modelling of composite reinforcement forming

    NASA Astrophysics Data System (ADS)

    Wang, D.; Naouar, N.; Vidal-Salle, E.; Boisse, P.

    2018-05-01

    In meso-scale finite element modeling, the yarns of the reinforcement are considered to be solids made of a continuous material in contact with their neighbors. The present paper consider the mechanical behavior of these yarns that can happen for some loadings of the reinforcement. The yarns present a specific mechanical behavior when under longitudinal compression because they are made up of a large number of fibers, Local buckling of the fibers causes the compressive stiffness of the continuous material representing the yarn to be much weaker than when under tension. In addition, longitudinal compression causes an important transverse expansion. It is shown that the transverse expansion can be depicted by a Poisson ratio that remained roughly constant when the yarn length and the compression strain varied. Buckling of the fibers significantly increases the transverse dimensions of the yarn which leads to a large Poisson ratio (up to 12 for a yarn analyzed in the present study). Meso-scale finite element simulations of reinforcements with binder yarns submitted to longitudinal compression showed that these improvements led to results in good agreement with micro-CT analyses.

  18. Longitudinal vibration and stability analysis of carbon nanotubes conveying viscous fluid

    NASA Astrophysics Data System (ADS)

    Oveissi, Soheil; Toghraie, Davood; Eftekhari, Seyyed Ali

    2016-09-01

    Nowadays, carbon nanotubes (CNT) play an important role in practical applications in fluidic devices. To this end, researchers have studied various aspects of vibration analysis of a behavior of CNT conveying fluid. In this paper, based on nonlocal elasticity theory, single-walled carbon nanotube (SWCNT) is simulated. To investigate and analyze the effect of internal fluid flow on the longitudinal vibration and stability of SWCNT, the equation of motion for longitudinal vibration is obtained by using Navier-Stokes equations. In the governing equation of motion, the interaction of fluid-structure, dynamic and fluid flow velocity along the axial coordinate of the nanotube and the nano-scale effect of the structure are considered. To solve the nonlocal longitudinal vibration equation, the approximate Galerkin method is employed and appropriate simply supported boundary conditions are applied. The results show that the axial vibrations of the nanotubesstrongly depend on the small-size effect. In addition, the fluid flowing in nanotube causes a decrease in the natural frequency of the system. It is obvious that the system natural frequencies reach zero at lower critical flow velocities as the wave number increases. Moreover, the critical flow velocity decreases as the nonlocal parameter increases.

  19. Three Approaches to Modeling Gene-Environment Interactions in Longitudinal Family Data: Gene-Smoking Interactions in Blood Pressure.

    PubMed

    Basson, Jacob; Sung, Yun Ju; de Las Fuentes, Lisa; Schwander, Karen L; Vazquez, Ana; Rao, Dabeeru C

    2016-01-01

    Blood pressure (BP) has been shown to be substantially heritable, yet identified genetic variants explain only a small fraction of the heritability. Gene-smoking interactions have detected novel BP loci in cross-sectional family data. Longitudinal family data are available and have additional promise to identify BP loci. However, this type of data presents unique analysis challenges. Although several methods for analyzing longitudinal family data are available, which method is the most appropriate and under what conditions has not been fully studied. Using data from three clinic visits from the Framingham Heart Study, we performed association analysis accounting for gene-smoking interactions in BP at 31,203 markers on chromosome 22. We evaluated three different modeling frameworks: generalized estimating equations (GEE), hierarchical linear modeling, and pedigree-based mixed modeling. The three models performed somewhat comparably, with multiple overlaps in the most strongly associated loci from each model. Loci with the greatest significance were more strongly supported in the longitudinal analyses than in any of the component single-visit analyses. The pedigree-based mixed model was more conservative, with less inflation in the variant main effect and greater deflation in the gene-smoking interactions. The GEE, but not the other two models, resulted in substantial inflation in the tail of the distribution when variants with minor allele frequency <1% were included in the analysis. The choice of analysis method should depend on the model and the structure and complexity of the familial and longitudinal data. © 2015 WILEY PERIODICALS, INC.

  20. Initiation and Continuation of Best Friends and Adolescents' Alcohol Consumption: Do Self-Esteem and Self-Control Function as Moderators?

    ERIC Educational Resources Information Center

    Larsen, Helle; Overbeek, Geertjan; Vermulst, Ad A.; Granic, Isabela; Engels, Rutger C. M. E.

    2010-01-01

    In this three-wave longitudinal survey, we investigated bi-directional longitudinal associations between best friends and adolescents' alcohol consumption. Additionally, since the relation between best friends and adolescents' drinking may be stronger if adolescents have not consumed alcohol yet, we examined this relation not only with regard to…

  1. The Longitudinal Course of Depression in Adoptive and Birth Mothers of Children with Intellectual Disabilities

    ERIC Educational Resources Information Center

    Glidden, Laraine M.; Jobe, Brian M.

    2006-01-01

    This report extends by an additional 6 years the longitudinal research of Glidden and Schoolcraft, who found that adoptive mothers of children with intellectual disabilities displayed low depression at the initial time of adoption and thereafter, whereas birth mothers reported significantly higher levels when their children were first diagnosed,…

  2. Effects of First Occasion Test Experience on Longitudinal Cognitive Change

    ERIC Educational Resources Information Center

    Salthouse, Timothy A.

    2013-01-01

    Effects of additional test experience on longitudinal change in 5 cognitive abilities was examined in a sample of healthy adults ranging from 18 to 80 years of age. Participants receiving experience with parallel versions of the cognitive tests on the first occasion had more positive cognitive change an average of 2.5 years later than participants…

  3. High angle of attack flying qualities criteria for longitudinal rate command systems

    NASA Technical Reports Server (NTRS)

    Wilson, David J.; Citurs, Kevin D.; Davidson, John B.

    1994-01-01

    This study was designed to investigate flying qualities requirements of alternate pitch command systems for fighter aircraft at high angle of attack. Flying qualities design guidelines have already been developed for angle of attack command systems at 30, 45, and 60 degrees angle of attack, so this research fills a similar need for rate command systems. Flying qualities tasks that require post-stall maneuvering were tested during piloted simulations in the McDonnell Douglas Aerospace Manned Air Combat Simulation facility. A generic fighter aircraft model was used to test angle of attack rate and pitch rate command systems for longitudinal gross acquisition and tracking tasks at high angle of attack. A wide range of longitudinal dynamic variations were tested at 30, 45, and 60 degrees angle of attack. Pilot comments, Cooper-Harper ratings, and pilot induced oscillation ratings were taken from five pilots from NASA, USN, CAF, and McDonnell Douglas Aerospace. This data was used to form longitudinal design guidelines for rate command systems at high angle of attack. These criteria provide control law design guidance for fighter aircraft at high angle of attack, low speed flight conditions. Additional time history analyses were conducted using the longitudinal gross acquisition data to look at potential agility measures of merit and correlate agility usage to flying qualities boundaries. This paper presents an overview of this research.

  4. Longitudinal changes in microstructural white matter metrics in Alzheimer's disease.

    PubMed

    Mayo, Chantel D; Mazerolle, Erin L; Ritchie, Lesley; Fisk, John D; Gawryluk, Jodie R

    2017-01-01

    Alzheimer's disease (AD) is a progressive neurodegenerative disorder. Current avenues of AD research focus on pre-symptomatic biomarkers that will assist with early diagnosis of AD. The majority of magnetic resonance imaging (MRI) based biomarker research to date has focused on neuronal loss in grey matter and there is a paucity of research on white matter. Longitudinal DTI data from the Alzheimer's Disease Neuroimaging Initiative 2 database were used to examine 1) the within-group microstructural white matter changes in individuals with AD and healthy controls at baseline and year one; and 2) the between-group microstructural differences in individuals with AD and healthy controls at both time points. 1) Within-group: longitudinal Tract-Based Spatial Statistics revealed that individuals with AD and healthy controls both had widespread reduced fractional anisotropy (FA) and increased mean diffusivity (MD) with changes in the hippocampal cingulum exclusive to the AD group. 2) Between-group: relative to healthy controls, individuals with AD had lower FA and higher MD in the hippocampal cingulum, as well as the corpus callosum, internal and external capsule; corona radiata; posterior thalamic radiation; superior and inferior longitudinal fasciculus; fronto-occipital fasciculus; cingulate gyri; fornix; uncinate fasciculus; and tapetum. The current results indicate that sensitivity to white matter microstructure is a promising avenue for AD biomarker research. Additional longitudinal studies on both white and grey matter are warranted to further evaluate potential clinical utility.

  5. Posttraumatic stress disorder, alone or additively with early life adversity, is associated with obesity and cardiometabolic risk.

    PubMed

    Farr, O M; Ko, B-J; Joung, K E; Zaichenko, L; Usher, N; Tsoukas, M; Thakkar, B; Davis, C R; Crowell, J A; Mantzoros, C S

    2015-05-01

    There is some evidence that posttraumatic stress disorder (PTSD) and early life adversity may influence metabolic outcomes such as obesity, diabetes, and cardiovascular disease. However, whether and how these interact is not clear. We analyzed data from a cross-sectional and longitudinal study to determine how PTSD severity influences obesity, insulin sensitivity, and key measures and biomarkers of cardiovascular risk. We then looked at how PTSD and early life adversity may interact to impact these same outcomes. PTSD severity is associated with increasing risk of obesity, diabetes, and cardiovascular disease, with higher symptoms correlating with higher values of BMI, leptin, fibrinogen, and blood pressure, and lower values of insulin sensitivity. PTSD and early life adversity have an additive effect on these metabolic outcomes. The longitudinal study confirmed findings from the cross sectional study and showed that fat mass, leptin, CRP, sICAM-1, and sTNFRII were significantly increased with higher PTSD severity during a 2.5 year follow-up period. Individuals with early life adversity and PTSD are at high risk and should be monitored carefully for obesity, insulin resistance, and cardiometabolic risk. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. 1.5 W high efficiency and tunable single-longitudinal-mode Ho:YLF ring laser based on Faraday effect.

    PubMed

    Wu, Jing; Ju, Youlun; Dai, Tongyu; Yao, Baoquan; Wang, Yuezhu

    2017-10-30

    We demonstrated an efficient and tunable single-longitudinal-mode Ho:YLF ring laser based on Faraday effect for application to measure atmospheric carbon dioxide (CO 2 ). Single-longitudinal-mode power at 2051.65 nm achieved 528 mW with the slope efficiency of 39.5% and the M 2 factor of 1.07, and the tunable range of about 178 GHz was obtained by inserting a Fabry-Perot (F-P) etalon with the thickness of 0.5 mm. In addition, the maximum single-longitudinal-mode power reached 1.5 W with the injected power of 528 mW at 2051.65 nm by master oscillator power amplifier (MOPA) technique. High efficiency and tunable single-longitudinal-mode based on Faraday effect around 2 μm has not been reported yet to the best of our knowledge.

  7. Analytic study of the conditions required for longitudinal stability of dual-wing aircraft

    DOE PAGES

    Andrews, Stephen Arthur; Perez, Ruben E.

    2017-05-11

    Recent studies of new, fuel-efficient transport aircraft have considered designs, which make use of two principal lifting surfaces to provide the required lift as well as trim and static stability. Such designs include open tandem-wings as well as closed joined and box-wings. As a group, these aircraft can be termed dual-wing designs. Our study developed a new analytic model, which takes into account the downwash from the two main wings and is sensitive to three important design variables: the relative areas of each wing, the streamwise separation of the wings, and the center of gravity position. This model was usedmore » to better understand trends in the dual-wing geometry on the stability, maneuverability, and lift-to-drag ratio of the aircraft. Dual-wing aircraft have been shown to have reduced the induced drag compared to the conventional designs. In addition, further drag reductions can be realized as the horizontal tail can be removed if the dual-wings have sufficient streamwise stagger to provide the moments necessary for trim and longitudinal stability. As both wings in a dual-wing system carry a significant fraction of the total lift, trends in such designs that led to longitudinal stability can differ from those of the conventional aircraft and have not been the subject of detailed investigation. Results from the analytic model showed that the longitudinal stability required either a reduction of the fore wing area or shifting the center of gravity forward from the midpoint of both wings' aerodynamic centers. Additionally, for wing configurations of approximately equal fore and aft wing areas, increasing the separation between the two wings decreased the stability of the aircraft. The source of this unusual behavior was the asymmetric distribution of downwash upstream and downstream of the wing. These relationships between dual-wing geometry and stability will provide initial guidance on the conceptual design of dual-wing aircraft and aid in the understanding of the results of more complex studies of such designs, furthering the development of future transport aircraft.« less

  8. Analytic study of the conditions required for longitudinal stability of dual-wing aircraft

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Andrews, Stephen Arthur; Perez, Ruben E.

    Recent studies of new, fuel-efficient transport aircraft have considered designs, which make use of two principal lifting surfaces to provide the required lift as well as trim and static stability. Such designs include open tandem-wings as well as closed joined and box-wings. As a group, these aircraft can be termed dual-wing designs. Our study developed a new analytic model, which takes into account the downwash from the two main wings and is sensitive to three important design variables: the relative areas of each wing, the streamwise separation of the wings, and the center of gravity position. This model was usedmore » to better understand trends in the dual-wing geometry on the stability, maneuverability, and lift-to-drag ratio of the aircraft. Dual-wing aircraft have been shown to have reduced the induced drag compared to the conventional designs. In addition, further drag reductions can be realized as the horizontal tail can be removed if the dual-wings have sufficient streamwise stagger to provide the moments necessary for trim and longitudinal stability. As both wings in a dual-wing system carry a significant fraction of the total lift, trends in such designs that led to longitudinal stability can differ from those of the conventional aircraft and have not been the subject of detailed investigation. Results from the analytic model showed that the longitudinal stability required either a reduction of the fore wing area or shifting the center of gravity forward from the midpoint of both wings' aerodynamic centers. Additionally, for wing configurations of approximately equal fore and aft wing areas, increasing the separation between the two wings decreased the stability of the aircraft. The source of this unusual behavior was the asymmetric distribution of downwash upstream and downstream of the wing. These relationships between dual-wing geometry and stability will provide initial guidance on the conceptual design of dual-wing aircraft and aid in the understanding of the results of more complex studies of such designs, furthering the development of future transport aircraft.« less

  9. Experimental study on titanium wire drawing with ultrasonic vibration.

    PubMed

    Liu, Shen; Shan, Xiaobiao; Guo, Kai; Yang, Yuancai; Xie, Tao

    2018-02-01

    Titanium and its alloys have been widely used in aerospace and biomedical industries, however, they are classified as difficult-to-machine materials. In this paper, ultrasonic vibration is imposed on the die to overcome the difficulties during conventional titanium wire drawing processes at the room temperature. Numerical simulations were performed to investigate the variation of axial stress within the contacting region and study the change of the drawing stress with several factors in terms of the longitudinal amplitude and frequency of the applied ultrasonic vibration, the diameter reduction ratio, and the drawing force. An experimental testing equipment was established to measure the drawing torque and rotational velocity of the coiler drum during the wire drawing process. The result indicates the drawing force increases with the growth of the drawing velocity and the reduction ratio, whether with or without vibrations. Application of either form of ultrasonic vibrations contributes to the further decrease of the drawing force, especially the longitudinal vibration with larger amplitude. SEM was employed to detect the surface morphology of the processed wires drawn under the three circumstances. The surface quality of the drawn wires with ultrasonic vibrations was apparently improved compared with those using conventional method. In addition, the longitudinal and torsional composite vibration was more effective for surface quality improvement than pure longitudinal vibration, however, at the cost of weakened drawing force reduction effect. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Mindfulness Mechanisms in Sports: Mediating Effects of Rumination and Emotion Regulation on Sport-Specific Coping.

    PubMed

    Josefsson, Torbjörn; Ivarsson, Andreas; Lindwall, Magnus; Gustafsson, Henrik; Stenling, Andreas; Böröy, Jan; Mattsson, Emil; Carnebratt, Jakob; Sevholt, Simon; Falkevik, Emil

    2017-01-01

    The main objective of the project was to examine a proposed theoretical model of mindfulness mechanisms in sports. We conducted two studies (the first study using a cross-sectional design and the second a longitudinal design) to investigate if rumination and emotion regulation mediate the relation between dispositional mindfulness and sport-specific coping. Two hundred and forty-two young elite athletes, drawn from various sports, were recruited for the cross-sectional study. For the longitudinal study, 65 elite athletes were recruited. All analyses were performed using Bayesian statistics. The path analyses showed credible indirect effects of dispositional mindfulness on coping via rumination and emotion regulation in both the cross-sectional study and the longitudinal study. Additionally, the results in both studies showed credible direct effects of dispositional mindfulness on rumination and emotion regulation. Further, credible direct effects of emotion regulation as well as rumination on coping were also found in both studies. Our findings support the theoretical model, indicating that rumination and emotion regulation function as essential mechanisms in the relation between dispositional mindfulness and sport-specific coping skills. Increased dispositional mindfulness in competitive athletes (i.e. by practicing mindfulness) may lead to reductions in rumination, as well as an improved capacity to regulate negative emotions. By doing so, athletes may improve their sport-related coping skills, and thereby enhance athletic performance.

  11. The Longitudinal Course of Gross Motor Activity in Schizophrenia – Within and between Episodes

    PubMed Central

    Walther, Sebastian; Stegmayer, Katharina; Horn, Helge; Rampa, Luca; Razavi, Nadja; Müller, Thomas J.; Strik, Werner

    2015-01-01

    Schizophrenia is associated with heterogeneous course of positive and negative symptoms. In addition, reduced motor activity as measured by wrist actigraphy has been reported. However, longitudinal studies of spontaneous motor activity are missing. We aimed to explore whether activity levels were stable within and between psychotic episodes. Furthermore, we investigated the association with the course of negative symptoms. In 45 medicated patients, we investigated motor behavior within a psychotic episode. In addition, we followed 18 medicated patients across 2 episodes. Wrist actigraphy and psychopathological ratings were applied. Within an episode symptoms changed but activity levels did not vary systematically. Activity at baseline predicted the course of negative symptoms. Between two episodes activity recordings were much more stable. Again, activity at the index episode predicted the outcome of negative symptoms. In sum, spontaneous motor activity shares trait and state characteristics, the latter are associated with negative symptom course. Actigraphy may therefore become an important ambulatory instrument to monitor negative symptoms and treatment outcome in schizophrenia. PMID:25698981

  12. NMR Water Self–Diffusion and Relaxation Studies on Sodium Polyacrylate Solutions and Gels in Physiologic Ionic Solutions

    PubMed Central

    Bai, Ruiliang; Basser, Peter J.; Briber, Robert M.; Horkay, Ferenc

    2013-01-01

    Water self-diffusion coefficients and longitudinal relaxation rates in sodium polyacrylate solutions and gels were measured by NMR, as a function of polymer content and structure in a physiological concentration range of monovalent and divalent cations, Ca2+ and Na+. Several physical models describing the self-diffusion of the solvent were applied and compared. A free-volume model was found to be in good agreement with the experimental results over a wide range of polymer concentrations. The longitudinal relaxation rate exhibited linear dependence on polymer concentration below a critical concentration and showed non-linear behavior at higher concentrations. Both the water self-diffusion and relaxation were less influenced by the polymer in the gel state than in the uncrosslinked polymer solutions. The effect of Na+ on the mobility of water molecules was practically undetectable. By contrast, addition of Ca2+ strongly increased the longitudinal relaxation rate while its effect on the self-diffusion coefficient was much less pronounced. PMID:24409001

  13. NMR Water Self-Diffusion and Relaxation Studies on Sodium Polyacrylate Solutions and Gels in Physiologic Ionic Solutions.

    PubMed

    Bai, Ruiliang; Basser, Peter J; Briber, Robert M; Horkay, Ferenc

    2014-03-15

    Water self-diffusion coefficients and longitudinal relaxation rates in sodium polyacrylate solutions and gels were measured by NMR, as a function of polymer content and structure in a physiological concentration range of monovalent and divalent cations, Ca 2+ and Na + . Several physical models describing the self-diffusion of the solvent were applied and compared. A free-volume model was found to be in good agreement with the experimental results over a wide range of polymer concentrations. The longitudinal relaxation rate exhibited linear dependence on polymer concentration below a critical concentration and showed non-linear behavior at higher concentrations. Both the water self-diffusion and relaxation were less influenced by the polymer in the gel state than in the uncrosslinked polymer solutions. The effect of Na + on the mobility of water molecules was practically undetectable. By contrast, addition of Ca 2+ strongly increased the longitudinal relaxation rate while its effect on the self-diffusion coefficient was much less pronounced.

  14. Longitudinal associations between key dietary behaviors and weight gain over time: transitions through the adolescent years.

    PubMed

    Laska, Melissa N; Murray, David M; Lytle, Leslie A; Harnack, Lisa J

    2012-01-01

    Previous studies have yielded inconsistent results when documenting the association between key dietary factors and adolescent weight change over time. The purpose of this study was to examine the extent to which changes in adolescent sugar-sweetened beverage (SSB), diet soda, breakfast, and fast-food consumption were associated with changes in BMI and percent body fat (PBF). This study analyzed data from a sample of 693 Minnesota adolescents followed over 2 years. Random coefficient models were used to examine the relationship between dietary intake and BMI and PBF and to separate cross-sectional and longitudinal associations. Adjusting for total physical activity, total energy intake, puberty, race, socioeconomic status, and age, cross-sectional findings indicated that for both males and females, breakfast consumption was significantly and inversely associated with BMI and PBF, and diet soda intake was significantly and positively associated with BMI and PBF among females. In longitudinal analyses, however, there were fewer significant associations. Among males there was evidence of a significant longitudinal association between SSB consumption and PBF; after adjustment for energy intake, an increase of one serving of SSB per day was associated with an increase of 0.7 units of PBF among males. This study adds to previous research through its methodological strengths, including adjustment for physical activity and energy intake assessed using state-of-the-art methods (i.e., accelerometers and 24-h dietary recalls), as well as its evaluation of both BMI and PBF. Additional research is needed to better understand the complex constellation of factors that contribute to adolescent weight gain over time.

  15. Big data in Parkinson's disease: using smartphones to remotely detect longitudinal disease phenotypes.

    PubMed

    Prince, John; Arora, Siddharth; de Vos, Maarten

    2018-04-26

    To better understand the longitudinal characteristics of Parkinson's disease (PD) through the analysis of finger tapping and memory tests collected remotely using smartphones. Using a large cohort (312 PD subjects and 236 controls) of participants in the mPower study, we extract clinically validated features from a finger tapping and memory test to monitor the longitudinal behaviour of study participants. We investigate any discrepancy in learning rates associated with motor and non-motor tasks between PD subjects and healthy controls. The ability of these features to predict self-assigned severity measures is assessed whilst simultaneously inspecting the severity scoring system for floor-ceiling effects. Finally, we study the relationship between motor and non-motor longitudinal behaviour to determine if separate aspects of the disease are dependent on one another. We find that the test performances of the most severe subjects show significant correlations with self-assigned severity measures. Interestingly, less severe subjects do not show significant correlations, which is shown to be a consequence of floor-ceiling effects within the mPower self-reporting severity system. We find that motor performance after practise is a better predictor of severity than baseline performance suggesting that starting performance at a new motor task is less representative of disease severity than the performance after the test has been learnt. We find PD subjects show significant impairments in motor ability as assessed through the alternating finger tapping (AFT) test in both the short- and long-term analyses. In the AFT and memory tests we demonstrate that PD subjects show a larger degree of longitudinal performance variability in addition to requiring more instances of a test to reach a steady state performance than healthy subjects. Our findings pave the way forward for objective assessment and quantification of longitudinal learning rates in PD. This can be particularly useful for symptom monitoring and assessing medication response. This study tries to tackle some of the major challenges associated with self-assessed severity labels by designing and validating features extracted from big datasets in PD, which could help identify digital biomarkers capable of providing measures of disease severity outside of a clinical environment.

  16. Does it take two to tango? Longitudinal effects of unilateral and bilateral integrative negotiation training.

    PubMed

    Zerres, Alfred; Hüffmeier, Joachim; Freund, Philipp Alexander; Backhaus, Klaus; Hertel, Guido

    2013-05-01

    This study assesses longitudinal effects of different training designs on joint negotiation performance. In so doing, the study experimentally compares (a) bilateral training of both the seller and the buyer within a dyad with both (b) a no-training control condition and 2 conditions with unilateral training of either (c) the buyer or (d) the seller. Moreover, underlying psychological mechanisms of the training effect are assessed. Results of the study with 360 participants reveal a significant overall training effect on negotiation outcomes that remains stable over time. Consistent with our hypotheses, unilateral negotiation training is only effective if the trained party is the seller, and it fails if the trained party is the buyer. Additional mediation analyses reveal exchange of priority-related information as a causal mechanism underlying these effects. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  17. Concurrent and prospective associations between facial affect recognition accuracy and childhood antisocial behavior.

    PubMed

    Bowen, Erica; Dixon, Louise

    2010-01-01

    This study examined the concurrent and prospective associations between children's ability to accurately recognize facial affect at age 8.5 and antisocial behavior at age 8.5 and 10.5 years in a sub sample of the Avon Longitudinal Study of Parents and Children cohort (5,396 children; 2,644, 49% males). All observed effects were small. It was found that at age 8.5 years, in contrast to nonantisocial children; antisocial children were less accurate at decoding happy and sad expressions when presented at low intensity. In addition, concurrent antisocial behavior was associated with misidentifying expressions of fear as expressions of sadness. In longitudinal analyses, children who misidentified fear as anger exhibited a decreased risk of antisocial behavior 2 years later. The study suggests that concurrent rather than future antisocial behavior is associated with facial affect recognition accuracy. (c) 2010 Wiley-Liss, Inc.

  18. [Causal relationship between assertiveness and adjustment in children: A short-term longitudinal study].

    PubMed

    Eguchi, Megumi; Hamaguchi, Yoshikazu

    2015-08-01

    This study examined the causal relationships between assertiveness and both internal and external adjustment in children. Elementary school children in grades four through six (N = 284) participated in the study, which used a short-term longitudinal design. The children completed questionnaires twice during a 6-months period. They responded to assertiveness questionnaires that included two components: "self-expression" and "consideration of others". They also completed a self-esteem scale as an index of internal adjustment, and the Class Life Satisfaction scale as an index of external adjustment. There was a positive causative relationship between "self-expression" and internal adjustment and between "consideration for others" and external adjustment. In addition, the effects on adjustment varied according to the type of assertiveness. Cluster analysis and MANOVA indicated that the group with high "self-expression" and "consideration for others" had high internal and external adjustment, while the children with poor assertiveness showed the lowest degree of adaptivity.

  19. First-Generation Undergraduate Students and the Impacts of the First Year of College: Additional Evidence

    ERIC Educational Resources Information Center

    Padgett, Ryan D.; Johnson, Megan P.; Pascarella, Ernest T.

    2012-01-01

    Using longitudinal data from the Wabash National Study of Liberal Arts Education, our findings suggest that first-generation students are at a significant disadvantage across cognitive and psychosocial outcomes compared to students whose parents have at least some postsecondary education. Furthermore, we tested for the conditional effects of good…

  20. The Relative Contributions of Vocabulary, Decoding, and Phonemic Awareness to Word Reading in English versus German

    ERIC Educational Resources Information Center

    Suggate, Sebastian; Reese, Elaine; Lenhard, Wolfgang; Schneider, Wolfgang

    2014-01-01

    Beginning readers in shallow orthographies acquire word reading skills more quickly than in deep orthographies like English. In addition to extending this evidence base by comparing reading acquisition in English with the more transparent German, we conducted a longitudinal study and investigated whether different early reading skills made…

  1. Selected Results of a Cross-Sectional/Longitudinal Research on Sex-Role Development in German Children.

    ERIC Educational Resources Information Center

    Trautner, Hanns Martin

    Following an outline of the theoretical approach and method of a study of components of sex role development among German children, results which concern ontogenetic changes in sex role stereotypes preferences are presented. In addition, interrelations of different components of sex role development and cognitive variables are analyzed. The…

  2. Girls' Spatial Skills and Arithmetic Strategies in First Grade as Predictors of Fifth-Grade Analytical Math Reasoning

    ERIC Educational Resources Information Center

    Casey, Beth M.; Lombardi, Caitlin McPherran; Pollock, Amanda; Fineman, Bonnie; Pezaris, Elizabeth

    2017-01-01

    This study investigated longitudinal pathways leading from early spatial skills in first-grade girls to their fifth-grade analytical math reasoning abilities (N = 138). First-grade assessments included spatial skills, verbal skills, addition/subtraction skills, and frequency of choice of a decomposition or retrieval strategy on the…

  3. Do Twins Have Lower Cognitive Ability than Singletons?

    ERIC Educational Resources Information Center

    Webbink, Dinand; Posthuma, Danielle; Boomsma, Dorret I.; de Geus, Eco J. C.; Visscher, Peter M.

    2008-01-01

    Previous studies based on population cohorts born at least 35 years ago, have reported appreciable childhood cognitive deficits for twins. We compared longitudinal IQ scores from approximately 188,000 singletons and some 6000 twins who went to primary school in the Netherlands from 1994 to 2003. In addition, we used a family-based design in which…

  4. Gender Differences in Depressive Symptoms during Adolescence: The Contributions of Weight-Related Concerns and Behaviors

    ERIC Educational Resources Information Center

    Vaughan, Christine A.; Halpern, Carolyn T.

    2010-01-01

    A theoretical model of gender differences in depressive symptoms during adolescence was evaluated using data from Waves I and II of the National Longitudinal Study of Adolescent Health. The theoretical model under examination was primarily informed by the gender-additive model of gender differences in depressive symptoms during adolescence…

  5. Orderly Change in a Stable World: The Antisocial Trait as a Chimera.

    ERIC Educational Resources Information Center

    Patterson, Gerald R.

    1993-01-01

    Used longitudinal data from Oregon Youth Study to examine quantitative and qualitative change. Used latent growth models to demonstrate changes in form and systematic changes in mean level for subgroup of boys. Factor analyses carried out at three ages showed that, over time, changes in form and addition of new problems were quantifiable and thus…

  6. Resisting Smoking when a Best Friend Smokes: Do Intrapersonal and Contextual Factors Matter?

    ERIC Educational Resources Information Center

    Tucker, Joan S.; Edelen, Maria Orlando; Go, Myung-Hyun; Pollard, Michael S.; Green, Harold D., Jr.; Kennedy, David P.

    2012-01-01

    This longitudinal study examines individual differences in the tendency to initiate (N = 4,612) and escalate (N = 2,837) smoking when adolescents gain a best friend who smokes. Potential moderating factors include self-esteem, depression, problem behavior, school and family bonds, and household access to cigarettes. In addition to acquiring a…

  7. Teacher-Course Evaluation: A Longitudinal Study of Response Stability and Instrument Reliability.

    ERIC Educational Resources Information Center

    McCollester, Charles W.; And Others

    The temporal context within which a teacher and course evaluation (TCE) is completed did not appear to be of crucial importance in affecting TCE responses. A sample of students was asked to evaluate, initially as freshmen and retrospectively as seniors, a specific teacher and course. Additional data on the student's academic status characteristics…

  8. Academic Momentum at University/College: Exploring the Roles of Prior Learning, Life Experience, and Ongoing Performance in Academic Achievement across Time

    ERIC Educational Resources Information Center

    Martin, Andrew J.; Wilson, Rachel; Liem, Gregory Arief D.; Ginns, Paul

    2014-01-01

    In the context of "academic momentum," a longitudinal study of university students (N = 904) showed high school achievement and ongoing university achievement predicted subsequent achievement through university. However, the impact of high school achievement diminished, while additive effects of ongoing university achievement continued.…

  9. Medical Commentary on the National Institute of Child Health and Development Consensus Statement on the Investigation of Child Sexual Abuse.

    ERIC Educational Resources Information Center

    Kerns, David L.

    1994-01-01

    The statement's principle medical research recommendations address the need for a longitudinal study of the healing of anogenital injuries and for the expansion and refinement of the understanding of normal anogenital anatomy. Four areas for additional medical research are described: uniform terminology, patient triage, sexually transmitted…

  10. To Stay or Leave: Factors That Impact Undergraduate Women's Persistence in Science Majors

    ERIC Educational Resources Information Center

    Gayles, Joy Gaston; Ampaw, Frim

    2016-01-01

    This study examined factors that influenced undergraduates' decision to enter, leave, or stay within science majors. In addition, we sought to understand if such decisions differed by gender and type of science major. Using Beginning Postsecondary Students (BPS) longitudinal survey data, we found that women were less likely to select a science…

  11. Higher serum bilirubin level as a protective factor for the development of diabetes in healthy Korean men: a 4 year retrospective longitudinal study.

    PubMed

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

    2014-01-01

    Bilirubin, a natural product of heme catabolism by heme oxygenase, one of key antioxidant enzymes, has been recognized as a substance with potent antioxidant and cytoprotective properties. Several studies have shown a significant negative relationship between serum bilirubin levels and the risk of metabolic disorders, including type 2 diabetes. However, longitudinal studies investigating the association of elevated serum bilirubin levels and type 2 diabetes are lacking. In the present study, we aimed to investigate the longitudinal effects of baseline serum bilirubin concentrations on the development of type 2 diabetes in healthy Korean men. This 4 year retrospective longitudinal observational study was conducted at the Asan Medical Center, Seoul, Republic of Korea. The study population consisted of 5960 men without type 2 diabetes who underwent routine health examinations in 2007 (baseline) and 2011 (follow-up). Baseline serum bilirubin concentrations were determined by the vanadate oxidation method. During a 4 year period, 409 incident cases of diabetes (6.9 %) were identified. Incident type 2 diabetes decreased across the baseline bilirubin quartile categories (P for trend <0.001). In multivariable-adjusted model, the relative risk (RR) for the development of type 2 diabetes was significantly lower in the highest (i.e., 1.30-2.00 mg/dl) than in the lowest bilirubin quartile category (i.e., ≤ 0.90 mg/dl), even after adjustment for confounding variables (RR=0.69, 95% confidence interval 0.48-0.99, P for trend = 0.041). The results indicate that serum total bilirubin level may provide additional information for predicting future development of type 2 diabetes in healthy subjects. © 2013.

  12. Methods to Limit Attrition in Longitudinal Comparative Effectiveness Trials: Lessons from the Lithium Use for Bipolar Disorder (LiTMUS) Study

    PubMed Central

    Sylvia, Louisa G.; Reilly-Harrington, Noreen A.; Leon, Andrew C.; Kansky, Christine I.; Ketter, Terence A.; Calabrese, Joseph R.; Thase, Michael E.; Bowden, Charles L.; Friedman, Edward S.; Ostacher, Michael J.; Iosifescu, Dan V.; Severe, Joanne; Nierenberg, Andrew A.

    2013-01-01

    Background High attrition rates which occur frequently in longitudinal clinical trials of interventions for bipolar disorder limit the interpretation of results. Purpose The aim of this article is to present design approaches that limited attrition in the Lithium Use for Bipolar Disorder (LiTMUS) Study. Methods LiTMUS was a 6-month randomized, longitudinal multi-site comparative effectiveness trial that examined bipolar participants who were at least mildly ill. Participants were randomized to either low to moderate doses of lithium or no lithium, in addition to other treatments needed for mood stabilization administered in a guideline-informed, empirically supported, and personalized fashion (N=283). Results Components of the study design that may have contributed to the low attrition rate of the study included use of: (1) an intent-to-treat design; (2) a randomized adjunctive single-blind design; (3) participant reimbursement; (4) intent-to-attend the next study visit (includes a discussion of attendance obstacles when intention is low); (5) quality care with limited participant burden; and (6) target windows for study visits. Limitations Site differences and the effectiveness and tolerability data have not been analyzed yet. Conclusions These components of the LiTMUS study design may have reduced the probability of attrition which would inform the design of future randomized clinical effectiveness trials. PMID:22076437

  13. The Longitudinal Force Measurement of CWR Tracks with Hetero-Cladding FBG Sensors: A Proof of Concept.

    PubMed

    Shao, Li-Yang; Zhang, Meng; Xie, Kaize; Zhang, Xinpu; Wang, Ping; Yan, Lianshan

    2016-12-18

    A new method has been proposed to accurately determine longitudinal additional force in continuous welded rail (CWR) on bridges via hetero-cladding fiber Bragg grating (HC-FBG) sensors. The HC-FBG sensor consists of two FBGs written in the same type of fiber but with different cladding diameters. The HC-FBGs have the same temperature sensitivity but different strain sensitivity because of the different areas of the cross section. The differential strain coefficient is defined as the relative wavelength differences of two FBGs with the change of applied longitudinal force. In the verification experiment in the lab, the HC-FBGs were attached on a section of rail model of which the material property is the same as that of rail on line. The temperature and differential strain sensitivity were calibrated using a universal testing machine. As shown by the test results, the linearity between the relative wavelength difference and the longitudinal additional force is greater than 0.9999. The differential strain sensitivity is 4.85 × 10 -6 /N. Moreover, the relative wavelength difference is not affected by the temperature change. Compared to the theoretical results, the accumulated error is controlled within 5.0%.

  14. Maturity-associated variation in change of direction and dribbling speed in early pubertal years and 5-year developmental changes in young soccer players.

    PubMed

    Valente-Dos-Santos, J; Coelho-E-Silva, M J; Vaz, V; Figueiredo, A J; Capranica, L; Sherar, L B; Elferink-Gemser, M T; Malina, R M

    2014-06-01

    The purpose of the current study was to assess the developmental changes in change of direction and dribbling speed in youth soccer players taking into account skeletal age (SA), maturity status, body size, estimated fat mass, aerobic endurance, lower limb explosive strength and annual volume of training. Eighty-three male soccer players aged 10-15 years (SA) at baseline were annually followed over 5 years, resulting in an average 4.4 observations per player. After testing for multicollinearity, multi-level regression modeling was used to examine the longitudinal developmental changes on change of direction and dribbling speed. Maturity-associated variability was significant in change of direction and also dribbling speed among young soccer players aged 12-14 years with better scores being performed by late maturers. Moreover, the predicted longitudinal scores for change of direction and dribbling speed improved with SA (P<0.01), SA2 (P<0.01) and skeletal maturity status entered as an additional developmental predictor (P<0.05). Estimated fat-free mass (P<0.01), aerobic endurance (P<0.01) and lower limb strength (P<0.01) were additional predictors in both models. The soccer-specific skill, dibbling speed, was also explained by annual volume of training (P<0.05). Skeletal maturity status explains inter-individual variability on maximal short-term run performances with and without the ball possession at early ages of participation in competitive soccer. The effects tend to persist across ages combined with longitudinal changes in body composition and functional fitness. In the particular case of the ball test, annual volume of training was also a longitudinal performance predictor.

  15. Utilizing wheel-ring architecture for stable and selectable single-longitudinal-mode erbium fiber laser

    NASA Astrophysics Data System (ADS)

    Yeh, Chien-Hung; Yang, Zi-Qing; Huang, Tzu-Jung; Chow, Chi-Wai

    2018-03-01

    To achieve a steady single-longitudinal-mode (SLM) erbium-doped fiber (EDF) laser, the wheel-ring architecture is proposed in the laser cavity. According to Vernier effect, the proposed wheel-ring can produce three different free spectrum ranges (FSRs) to serve as the mode-filter for suppressing the densely multi-longitudinal-mode (MLM). Here, to complete wavelength-tunable EDF laser, an optical tunable bandpass filter (OTBF) is utilized inside the cavity for tuning arbitrarily. In addition, the entire output performances of the proposed EDF wheel-ring laser are also discussed and analyzed experimentally.

  16. The context of aggressive behavior in marriage: a longitudinal study of newlyweds.

    PubMed

    Frye, Nancy E; Karney, Benjamin R

    2006-03-01

    Under what circumstances are spouses more or less likely to engage in aggressive behaviors? To address this question, the current study drew on multiple longitudinal assessments of 1st-married newlyweds to examine correlates of within-subject variability in aggressive behavior. Controlling for marital satisfaction, the authors found that spouses were more likely to engage in physical aggression at times when they engaged in higher levels of psychological aggression. Additionally, husbands reporting higher levels of chronic stress were more likely to engage in physical aggression overall and were more likely to engage in physical aggression when they were experiencing higher than average levels of acute stress. These results highlight how demands and supports in the context external to a marriage may affect processes within the marriage. Copyright 2006 APA, all rights reserved.

  17. High-resolution investigation of longitudinal modes of a GaN-based blue laser diode

    NASA Astrophysics Data System (ADS)

    Al-Basheer, Watheq; Aljalal, Abdulaziz; Gasmi, Khaled; Adigun, Taofeek O.

    2017-05-01

    Typical emission spectra of GaN-based blue laser diodes are known to have irregular shapes. Hence, well-resolved study of their spectra may help in understanding the origin of their spectral shapes irregularity. In this paper, the spectra of a commercial GaN-based blue laser diode are studied as a function of injection current and temperature using a spectrometer with highresolution of 0.003-nm over the spectral region 440 - 450 nm. The obtained laser spectra are used to track the longitudinal modes evolution as a function of operating currents and temperatures as well as to precisely map single mode operation. In addition, yielded laser spectra will be utilized to evaluate few parameters related to the laser diode, such as mode spacing, optical gain, slope efficiency and threshold current at certain temperature.

  18. The vector structure of active magnetic fields

    NASA Technical Reports Server (NTRS)

    Parker, E. N.

    1985-01-01

    Observations are needed to show the form of the strains introduced into the fields above the surface of the Sun. The longitudinal component alone does not provide the basic information, so that it has been necessary in the past to use the filamentary structure observed in H sub alpha to supplement the longitudinal information. Vector measurements provide the additional essential information to determine the strains, with the filamentary structure available as a check for consistency. It is to be expected, then, that vector measurements will permit a direct mapping of the strains imposed on the magnetic fields of active regions. It will be interesting to study the relation of those strains to the emergence of magnetic flux, flares, eruptive prominences, etc. In particular we may hope to study the relaxation of the strains via the dynamical nonequilibrium.

  19. Analysis of Self-Excited Combustion Instabilities Using Decomposition Techniques

    DTIC Science & Technology

    2016-07-05

    are evaluated for the study of self-excited longitudinal combustion instabilities in laboratory-scaled single-element gas turbine and rocket...Air Force Base, California 93524 DOI: 10.2514/1.J054557 Proper orthogonal decomposition and dynamic mode decomposition are evaluated for the study of...instabilities. In addition, we also evaluate the capabilities of the methods to deal with data sets of different spatial extents and temporal resolution

  20. Impact of longitudinal flying qualities upon the design of a transport with active controls

    NASA Technical Reports Server (NTRS)

    Sliwa, S. M.

    1980-01-01

    Direct constrained parameter optimization was used to optimally size a medium range transport for minimum direct operating cost. Several stability and control constraints were varied to study the sensitivity of the configuration to specifying the unaugmented flying qualities of transports designed with relaxed static stability. Additionally, a number of handling quality related design constants were studied with respect to their impact to the design.

  1. A longitudinal study of smokers' exposure to cigarette smoke and the effects of spontaneous product switching.

    PubMed

    Cunningham, Anthony; Sommarström, Johan; Camacho, Oscar M; Sisodiya, Ajit S; Prasad, Krishna

    2015-06-01

    A challenge in investigating the effect of public health policies on cigarette consumption and exposure arises from variation in a smoker's exposure from cigarette to cigarette and the considerable differences between smokers. In addition, limited data are available on the effects of spontaneous product switching on a smoker's cigarette consumption and exposure to smoke constituents. Over 1000 adult smokers of the same commercial 10mg International Organization for Standardization (ISO) tar yield cigarette were recruited into the non-residential, longitudinal study across 10 cities in Germany. Cigarette consumption, mouth level exposure to tar and nicotine and biomarkers of exposure to nicotine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone were measured every 6months over a 3 and a half year period. Cigarette consumption remained stable through the study period and did not vary significantly when smokers spontaneously switched products. Mouth level exposure decreased for smokers (n=111) who switched to cigarettes of 7mg ISO tar yield or lower. In addition, downward trends in mouth level exposure estimates were observed for smokers who did not switch cigarettes. Data from this study illustrate some of the challenges in measuring smokers' long-term exposure to smoke constituents in their everyday environment. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  2. Associations of Renin-Angiotensin-Aldosterone System Genes With Blood Pressure Changes and Hypertension Incidence.

    PubMed

    He, William J; Li, Changwei; Rao, Dabeeru C; Hixson, James E; Huang, Jianfeng; Cao, Jie; Rice, Treva K; Shimmin, Lawrence C; Gu, Dongfeng; Kelly, Tanika N

    2015-11-01

    The renin-angiotensin-aldosterone system (RAAS) plays an important role in blood pressure (BP) regulation. The current study uses single-marker and gene-based analyses to examine the association between RAAS genes and longitudinal BP phenotypes in a Han Chinese population. A total of 1,768 participants from the Genetic Epidemiology Network of Salt Sensitivity (GenSalt) follow-up study were included in the current study. Twenty-seven BP measurements were taken using random-zero sphygmomanometers at baseline and 2 follow-up visits. Mixed-effect models were used to assess the additive associations of 106 single-nucleotide polymorphisms (SNPs) in 10 RAAS genes with longitudinal BP changes and hypertension incidence. Gene-based analyses were conducted using the truncated product method. Attempts were made to replicate significant findings among Asian participants of the Multi-ethnic Study of Atherosclerosis (MESA). False discovery rate procedures were used to adjust for multiple testing. During an average of 7.2 years of follow-up, average systolic and diastolic BP increased, and 32.1% (512) of participants free from hypertension at baseline developed hypertension. NR3C2 SNPs rs7694064 and rs6856803 were significantly associated with longitudinal changes in systolic BP (P interaction = 6.9×10(-5) and 8.2×10(-4), respectively). Through gene-based analysis, NR3C2 was found to be significantly associated with longitudinal systolic BP change (P value of 1.00×10(-7)), even after removal of significant markers rs7694064 and rs6856803 from the analysis. The association between NR3C2 and longitudinal systolic BP change was replicated in Asian MESA participants (P value of 1.00×10(-4)). These findings indicate that NR3C2 may play an important role in BP progression and development of hypertension. © American Journal of Hypertension, Ltd 2015. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Stent longitudinal integrity bench insights into a clinical problem.

    PubMed

    Ormiston, John A; Webber, Bruce; Webster, Mark W I

    2011-12-01

    Standardized bench-top compression and elongation testing was undertaken to assess the longitudinal strength of contemporary stents. Insights gained may improve clinical stent choice and deployment techniques, and facilitate future stent design improvements. The hoops of coronary stents provide radial support, and connectors hold hoops together. Strut material, shape, and thickness, along with connector number and configuration, provide the balance between stent flexibility and longitudinal integrity. Longitudinal distortion manifests as length change, strut overlap, strut separation, malapposition, and luminal obstruction. These may predispose to restenosis and stent thrombosis, obstruct passage of devices, be misinterpreted as strut fracture, and require additional stenting. The force required to compress and to elongate 7 contemporary stents was measured with an Instron universal testing machine (Norwood, Massachusetts). Stents deployed in a silicone phantom damaged by a balloon or guide catheter were imaged by microcomputed tomography to understand better the appearances and effects of longitudinal distortion. Stents with 2 connectors (Boston Scientific [Natick, Massachusetts] Omega and Medtronic [Santa Rosa, California] Driver) required significantly less force to be compressed up to 5 mm and elongated by 1 mm than designs with more connectors. The 6-connector Cypher Select required significantly more force to be elongated 5 mm than other designs. Stents with 2 connectors between hoops have less longitudinal strength when exposed to compressing or elongating forces than those with more connectors. This independent, standardized study may assist stent selection in clinical situations where longitudinal integrity is important, and may aid future design improvements. Stent longitudinal strength, the resistance to shortening or elongation, appears related to the number of connectors between hoops. Using a standardized testing protocol, designs with 2 connectors were more likely to shorten or elongate than those with more connectors. Distortion may be recognized clinically as bunching or separation of struts, and may be confused with strut fracture. Without post-dilation or further stent deployment, the patient may be at increased risk for adverse clinical events. A stent design change ensuring 3 connectors, especially at the proximal end of a stent, should increase longitudinal integrity, but perhaps at the expense of stent flexibility. Copyright © 2011 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  4. A Longitudinal Investigation of Commitment Dynamics in Cohabiting Relationships

    PubMed Central

    Rhoades, Galena K.; Stanley, Scott M.; Markman, Howard J.

    2012-01-01

    This longitudinal study followed 120 cohabiting couples over 8 months to test hypotheses derived from commitment theory about how two types of commitment (dedication and constraints) operate during cohabitation. In nearly half the couples, there were large differences between partners in terms of dedication. These differences were associated with lower relationship adjustment, even controlling for overall level of dedication. Further, among couples who believed in the institution of marriage, cohabiting women were, on average, more dedicated than their partners. Additionally, there was evidence that constraints (e.g., signing a lease, having a joint bank account) may make it less likely that couples will break-up, regardless of relationship dedication. This finding was strongest for women and for those with higher income levels. PMID:22736881

  5. Optical imaging measurements of oxygen transport fluctuations and gradients in tumor microvascular networks

    NASA Astrophysics Data System (ADS)

    Sorg, Brian S.; Hardee, Matthew E.; Moeller, Benjamin J.; Dewhirst, Mark W.

    2006-02-01

    It is well established that hypoxia can influence tumor biology and physiology, gene expression, metastatic potential, treatment efficacy, and patient survival. Most human solid tumors have been shown to have some hypoxic regions, thus there is a strong motivation to understand the various causes of hypoxia. One key to understanding tumor hypoxia involves the study of oxygen transport to tumors, and the connection between hypoxia, tumor microvasculature, and the tumor microenvironment. Recent research has suggested that the causes of tumor hypoxia are much more complex than indicated by the classical paradigms ("chronic" and "acute" hypoxia), and several potential factors have been identified. Two such factors are temporal fluctuations in tissue pO II and longitudinal gradients in oxygen transport. Research has shown the existence of low frequency (<2 cycles per minute) fluctuations in tumor pO II without cessation of blood flow that can lead to transient hypoxia. In addition, longitudinal gradients in tumor pO II along the arteriolar afferent direction have been documented in window chamber tumors. However, the causes of the pO II temporal fluctuations and longitudinal gradients are not exactly known, and the clinical significance of these observations is not well understood. In this preliminary study, we demonstrate the potential of optical imaging measurements of hemoglobin saturation to add new information in these areas. Slow temporal fluctuations of hemoglobin saturation (HbSat) and gradients in the average HbSat were observed in some 4T1 mouse mammary carcinoma microvessels. With additional research, the mechanisms behind these phenomena and insights into their clinical significance may be revealed.

  6. Rumination as a Mechanism Linking Stressful Life Events to Symptoms of Depression and Anxiety: Longitudinal Evidence in Early Adolescents and Adults

    PubMed Central

    Michl, Louisa C.; McLaughlin, Katie A.; Shepherd, Kathrine; Nolen-Hoeksema, Susan

    2014-01-01

    Rumination is a well-established risk factor for the onset of major depression and anxiety symptomatology in both adolescents and adults. Despite the robust associations between rumination and internalizing psychopathology, there is a dearth of research examining factors that might lead to a ruminative response style. In the current study, we examined whether social environmental experiences were associated with rumination. Specifically, we evaluated whether self-reported exposure to stressful life events predicted subsequent increases in rumination. We also investigated whether rumination served as a mechanism underlying the longitudinal association between self-reported stressful life events and internalizing symptoms. Self-reported stressful life events, rumination, and symptoms of depression and anxiety were assessed in 2 separate longitudinal samples. A sample of early adolescents (N = 1,065) was assessed at 3 time points spanning 7 months. A sample of adults (N = 1,132) was assessed at 2 time points spanning 12 months. In both samples, self-reported exposure to stressful life events was associated longitudinally with increased engagement in rumination. In addition, rumination mediated the longitudinal relationship between self-reported stressors and symptoms of anxiety in both samples and the relationship between self-reported life events and symptoms of depression in the adult sample. Identifying the psychological and neurobiological mechanisms that explain a greater propensity for rumination following stressors remains an important goal for future research. This study provides novel evidence for the role of stressful life events in shaping characteristic responses to distress, specifically engagement in rumination, highlighting potentially useful targets for interventions aimed at preventing the onset of depression and anxiety. PMID:23713497

  7. 47. Photocopy of plans. Draftsman unknown, 1916 ADDITION TO CAR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    47. Photocopy of plans. Draftsman unknown, 1916 ADDITION TO CAR BARN. LONGITUDINAL AND CROSS SECTIONS. VIEWS TO SOUTH AND WEST. - Milwaukee Light, Heat & Traction Company, 8336 West Lapham Street, West Allis, Milwaukee County, WI

  8. Longitudinal assessment of short-term memory deterioration in a logopenic variant primary progressive aphasia with post-mortem confirmed Alzheimer's Disease pathology.

    PubMed

    Tree, Jeremy; Kay, Janice

    2015-09-01

    In the field of dementia research, there are reports of neurodegenerative cases with a focal loss of language, termed primary progressive aphasia (PPA). Currently, this condition has been further sub-classified, with the most recent sub-type dubbed logopenic variant (PPA-LV). As yet, there remains somewhat limited evaluation of the characteristics of this condition, with no studies providing longitudinal assessment accompanied by post-mortem examination. Moreover, a key characteristic of the PPA-LV case is a deterioration of phonological short-term memory, but again little work has scrutinized the nature of this impairment over time. The current study seeks to redress these oversights and presents detailed longitudinal examination of language and memory function in a case of PPA-LV, with special focus on tests linked to components of phonological short-term memory function. Our findings are then considered with reference to a contemporary model of the neuropsychology of phonological short-term memory. Additionally, post-mortem examinations indicated Alzheimer's disease type pathology, providing further evidence that the PPA-LV presentation may reflect an atypical presentation of this condition. © 2014 The British Psychological Society.

  9. Low-Speed Wind-Tunnel Investigation of Blowing Boundary-Layer Control on Leading- and Trailing-Edge Flaps of a Large-Scale, Low-Aspect-Ratio, 45 Swept-wing Airplane Configuration

    NASA Technical Reports Server (NTRS)

    Maki, Ralph L.

    1959-01-01

    Blowing boundary-layer control was applied to the leading- and trailing-edge flaps of a 45 deg sweptback-wing complete model in a full-scale low-speed wind-tunnel study. The principal purpose of the study was to determine the effects of leading-edge flap deflection and boundary-layer control on maximum lift and longitudinal stability. Leading-edge flap deflection alone was sufficient to maintain static longitudinal stability without trailing-edge flaps. However, leading-edge flap blowing was required to maintain longitudinal stability by delaying leading-edge flow separation when trailing-edge flaps were deflected either with or without blowing. Partial-span leading-edge flaps deflected 60 deg with moderate blowing gave the major increase in maximum lift, although higher deflection and additional blowing gave some further increase. Inboard of 0.4 semispan leading-edge flap deflection could be reduced to 40 deg and/or blowing could be omitted with only small loss in maximum lift. Trailing-edge flap lift increments were increased by boundary-layer control for deflections greater than 45 deg. Maximum lift was not increased with deflected trailing-edge flaps with blowing.

  10. Measurement bias detection with Kronecker product restricted models for multivariate longitudinal data: an illustration with health-related quality of life data from thirteen measurement occasions

    PubMed Central

    Verdam, Mathilde G. E.; Oort, Frans J.

    2014-01-01

    Highlights Application of Kronecker product to construct parsimonious structural equation models for multivariate longitudinal data. A method for the investigation of measurement bias with Kronecker product restricted models. Application of these methods to health-related quality of life data from bone metastasis patients, collected at 13 consecutive measurement occasions. The use of curves to facilitate substantive interpretation of apparent measurement bias. Assessment of change in common factor means, after accounting for apparent measurement bias. Longitudinal measurement invariance is usually investigated with a longitudinal factor model (LFM). However, with multiple measurement occasions, the number of parameters to be estimated increases with a multiple of the number of measurement occasions. To guard against too low ratios of numbers of subjects and numbers of parameters, we can use Kronecker product restrictions to model the multivariate longitudinal structure of the data. These restrictions can be imposed on all parameter matrices, including measurement invariance restrictions on factor loadings and intercepts. The resulting models are parsimonious and have attractive interpretation, but require different methods for the investigation of measurement bias. Specifically, additional parameter matrices are introduced to accommodate possible violations of measurement invariance. These additional matrices consist of measurement bias parameters that are either fixed at zero or free to be estimated. In cases of measurement bias, it is also possible to model the bias over time, e.g., with linear or non-linear curves. Measurement bias detection with Kronecker product restricted models will be illustrated with multivariate longitudinal data from 682 bone metastasis patients whose health-related quality of life (HRQL) was measured at 13 consecutive weeks. PMID:25295016

  11. Measurement bias detection with Kronecker product restricted models for multivariate longitudinal data: an illustration with health-related quality of life data from thirteen measurement occasions.

    PubMed

    Verdam, Mathilde G E; Oort, Frans J

    2014-01-01

    Application of Kronecker product to construct parsimonious structural equation models for multivariate longitudinal data.A method for the investigation of measurement bias with Kronecker product restricted models.Application of these methods to health-related quality of life data from bone metastasis patients, collected at 13 consecutive measurement occasions.The use of curves to facilitate substantive interpretation of apparent measurement bias.Assessment of change in common factor means, after accounting for apparent measurement bias.Longitudinal measurement invariance is usually investigated with a longitudinal factor model (LFM). However, with multiple measurement occasions, the number of parameters to be estimated increases with a multiple of the number of measurement occasions. To guard against too low ratios of numbers of subjects and numbers of parameters, we can use Kronecker product restrictions to model the multivariate longitudinal structure of the data. These restrictions can be imposed on all parameter matrices, including measurement invariance restrictions on factor loadings and intercepts. The resulting models are parsimonious and have attractive interpretation, but require different methods for the investigation of measurement bias. Specifically, additional parameter matrices are introduced to accommodate possible violations of measurement invariance. These additional matrices consist of measurement bias parameters that are either fixed at zero or free to be estimated. In cases of measurement bias, it is also possible to model the bias over time, e.g., with linear or non-linear curves. Measurement bias detection with Kronecker product restricted models will be illustrated with multivariate longitudinal data from 682 bone metastasis patients whose health-related quality of life (HRQL) was measured at 13 consecutive weeks.

  12. How Changes in Psychosocial Job Characteristics Impact Burnout in Nurses: A Longitudinal Analysis.

    PubMed

    Pisanti, Renato; van der Doef, Margot; Maes, Stan; Meier, Laurenz Linus; Lazzari, David; Violani, Cristiano

    2016-01-01

    The main aim of this longitudinal study was to test the Job Demand-Control-Support (JDCS) model and to analyze whether changes in psychosocial job characteristics are related to (changes in) burnout. Previous studies on the effects of JDCS variables on burnout dimensions have indicated that the iso-strain hypothesis (i.e., high job demands, low control, and low support additively predict high stress reactions) and the buffer hypotheses (i.e., high job control and/or social support is expected to moderate the negative impact of high demands on stress reactions) have hardly been examined concurrently in a longitudinal design; and that the effects of changes of psychosocial job variables on burnout dimensions have hardly been analyzed. This two wave study was carried out over a period of 14 months in a sample of 217 Italian nurses. Hierarchical regression analyses were used to test the cross lagged main and interactive effects of JDCS variables, and to analyse the across-time effects of changes in JDCS dimensions on burnout variables. The Time 1 job characteristics explained 2-8% of the variance in the Time 2 burnout dimensions, but no support for the additive, or the buffer hypothesis of the JDCS model was found. Changes in job characteristics explained an additional 3-20% of variance in the Time 2 burnout dimensions. Specifically, high levels of emotional exhaustion at Time 2 were explained by high levels of social support at Time 1, and unfavorable changes in demands, control, and support over time; high depersonalization at Time 2 was explained by high social support at time 1 and by an increase in demands over time; and high personal accomplishment at Time 2 was predicted by high demands, high control, interactive effect demands × control × social support, at Time 1, and by a decrease in demands over time. No reversed effects of burnout on work characteristics have been found. Our findings suggest that the work environment is subject to changes: the majority of employees experienced considerable changes in all job conditions over time. These changes impacted employee burnout. Limitations and implications of the study are discussed.

  13. How Changes in Psychosocial Job Characteristics Impact Burnout in Nurses: A Longitudinal Analysis

    PubMed Central

    Pisanti, Renato; van der Doef, Margot; Maes, Stan; Meier, Laurenz Linus; Lazzari, David; Violani, Cristiano

    2016-01-01

    Aims: The main aim of this longitudinal study was to test the Job Demand-Control-Support (JDCS) model and to analyze whether changes in psychosocial job characteristics are related to (changes in) burnout. Background: Previous studies on the effects of JDCS variables on burnout dimensions have indicated that the iso-strain hypothesis (i.e., high job demands, low control, and low support additively predict high stress reactions) and the buffer hypotheses (i.e., high job control and/or social support is expected to moderate the negative impact of high demands on stress reactions) have hardly been examined concurrently in a longitudinal design; and that the effects of changes of psychosocial job variables on burnout dimensions have hardly been analyzed. Design: This two wave study was carried out over a period of 14 months in a sample of 217 Italian nurses. Method: Hierarchical regression analyses were used to test the cross lagged main and interactive effects of JDCS variables, and to analyse the across-time effects of changes in JDCS dimensions on burnout variables. Results: The Time 1 job characteristics explained 2–8% of the variance in the Time 2 burnout dimensions, but no support for the additive, or the buffer hypothesis of the JDCS model was found. Changes in job characteristics explained an additional 3–20% of variance in the Time 2 burnout dimensions. Specifically, high levels of emotional exhaustion at Time 2 were explained by high levels of social support at Time 1, and unfavorable changes in demands, control, and support over time; high depersonalization at Time 2 was explained by high social support at time 1 and by an increase in demands over time; and high personal accomplishment at Time 2 was predicted by high demands, high control, interactive effect demands × control × social support, at Time 1, and by a decrease in demands over time. No reversed effects of burnout on work characteristics have been found. Conclusion: Our findings suggest that the work environment is subject to changes: the majority of employees experienced considerable changes in all job conditions over time. These changes impacted employee burnout. Limitations and implications of the study are discussed. PMID:27507952

  14. Increased longitudinal contractility and diastolic function at rest in well-trained amateur Marathon runners: a speckle tracking echocardiography study

    PubMed Central

    2014-01-01

    Background Regular physical activity reduces cardiovascular risk. There is concern that Marathon running might acutely damage the heart. It is unknown to what extent intensive physical endurance activity influences the cardiac mechanics at resting condition. Methods Eighty-four amateur marathon runners (43 women and 41 men) from Berlin-Brandenburg area who had completed at least one marathon previously underwent clinical examination and echocardiography at least 10 days before the Berlin Marathon at rest. Standard transthoracic echocardiography and 2D strain and strain rate analysis were performed. The 2D Strain and strain rate values were compared to previous published data of healthy untrained individuals. Results The average global longitudinal peak systolic strain of the left ventricle was -23 +/- 2% with peak systolic strain rate -1.39 +/- 0.21/s, early diastolic strain rate 2.0 +/- 0.40/s and late diastolic strain rate 1.21 +/- 0.31/s. These values are significantly higher compared to the previous published values of normal age-adjusted individuals. In addition, no age-related decline of longitudinal contractility in well-trained athletes was observed. Conclusions There is increased overall longitudinal myocardial contractility at rest in experienced endurance athletes compared to the published normal values in the literature indicating a preserved and even supra-normal contractility in the athletes. There is no age dependent decline of the longitudinal 2D Strain values. This underlines the beneficial effects of regular physical exercise even in advanced age. PMID:24571726

  15. Affect systems, changes in body mass index, disordered eating and stress: an 18-month longitudinal study in women

    PubMed Central

    Kupeli, N.; Norton, S.; Chilcot, J.; Campbell, I. C.; Schmidt, U. H.; Troop, N. A.

    2017-01-01

    ABSTRACT Background: Evidence suggests that stress plays a role in changes in body weight and disordered eating. The present study examined the effect of mood, affect systems (attachment and social rank) and affect regulatory processes (self-criticism, self-reassurance) on the stress process and how this impacts on changes in weight and disordered eating. Methods: A large sample of women participated in a community-based prospective, longitudinal online study in which measures of body mass index (BMI), disordered eating, perceived stress, attachment, social rank, mood and self-criticism/reassurance were measured at 6-monthly intervals over an 18-month period. Results: Latent Growth Curve Modelling showed that BMI increased over 18 months while stress and disordered eating decreased and that these changes were predicted by high baseline levels of these constructs. Independently of this, however, increases in stress predicted a reduction in BMI which was, itself, predicted by baseline levels of self-hatred and unfavourable social comparison. Conclusions: This study adds support to the evidence that stress is important in weight change. In addition, this is the first study to show in a longitudinal design, that social rank and self-criticism (as opposed to self-reassurance) at times of difficulty predict increases in stress and, thus, suggests a role for these constructs in weight regulation. PMID:28553564

  16. Longitudinal development of subtraction performance in elementary school.

    PubMed

    Artemenko, Christina; Pixner, Silvia; Moeller, Korbinian; Nuerk, Hans-Christoph

    2017-10-05

    A major goal of education in elementary mathematics is the mastery of arithmetic operations. However, research on subtraction is rather scarce, probably because subtraction is often implicitly assumed to be cognitively similar to addition, its mathematical inverse. To evaluate this assumption, we examined the relation between the borrow effect in subtraction and the carry effect in addition, and the developmental trajectory of the borrow effect in children using a choice reaction paradigm in a longitudinal study. In contrast to the carry effect in adults, carry and borrow effects in children were found to be categorical rather than continuous. From grades 3 to 4, children became more proficient in two-digit subtraction in general, but not in performing the borrow operation in particular. Thus, we observed no specific developmental progress in place-value computation, but a general improvement in subtraction procedures. Statement of contribution What is already known on this subject? The borrow operation increases difficulty in two-digit subtraction in adults. The carry effect in addition, as the inverse operation of borrowing, comprises categorical and continuous processing characteristics. What does this study add? In contrast to the carry effect in adults, the borrow and carry effects are categorical in elementary school children. Children generally improve in subtraction performance from grades 3 to 4 but do not progress in place-value computation in particular. © 2017 The British Psychological Society.

  17. Is childhood obesity influenced by dog ownership? No cross-sectional or longitudinal evidence.

    PubMed

    Westgarth, Carri; Heron, Jon; Ness, Andrew R; Bundred, Peter; Gaskell, Rosalind M; Coyne, Karen; German, Alexander J; McCune, Sandra; Dawson, Susan

    2012-01-01

    To examine whether dog ownership is associated with lower risk of childhood obesity. Cross-sectional study of 7,759 children at age 7 years in the Avon Longitudinal Study of Parents and Children (ALSPAC) in the UK. In addition, longitudinal analyses were conducted between age 7 and 9 years. BMI at age 7 and 9 years was calculated from clinic-measured weight and height and standardised in reference to 1990 UK data. Dog ownership data were collected by carer questionnaire at various time points. After adjustment for confounding factors associated with dog ownership or obesity, there was no evidence of an association between obesity and dog ownership at 7 years OR = 1.18, 95% confidence interval = 0.88-1.59, p = 0.27), or dog ownership history. There was also no evidence for an effect of dog ownership on BMI change between 7 and 9 years, nor acquisition of a dog on the change in weight status of obese children between 7 and 9 years. This study provides no evidence for a protective effect of dog ownership on the development of childhood obesity. Further investigation is required to determine the impact of dog ownership on physical activity in overweight and obese children. Copyright © 2012 S. Karger GmbH, Freiburg

  18. Personality traits and educational identity formation in late adolescents: longitudinal associations and academic progress.

    PubMed

    Klimstra, Theo A; Luyckx, Koen; Germeijs, Veerle; Meeus, Wim H J; Goossens, Luc

    2012-03-01

    Changes in personality traits in late adolescence and young adulthood are believed to co-occur with changes in identity, but little research is available that supports this hypothesis. The present study addressed this relatively understudied area of research by examining longitudinal associations of Big Five personality traits (i.e., Neuroticism, Extraversion, Openness, Agreeableness, and Conscientiousness) with dimensions of identity formation (i.e., identification with commitment and exploration in depth) in the domain of education. For this purpose, we used four annual waves of longitudinal data on 485 Belgian late adolescents (87.4% female; mean age at T1 = 18.6 years) covering a 3-year period. Multivariate growth models revealed that changes in Big Five personality traits were related to changes in identification with commitment and exploration in depth. Cross-lagged panel models uncovered that, except for Openness, all Big Five traits predicted educational identity dimensions. Educational identity dimensions only predicted Neuroticism. In addition, adolescents with higher levels on the personality trait of Conscientiousness faced fewer study delays. In sum, the present study adds to the growing literature that explores the antecedents, correlates, and consequences of personality trait development by uncovering the interplay of personality traits, educational identity dimensions, and academic progress in late adolescents.

  19. Evaluation of Dentin Defect Formation during Retreatment with Hand and Rotary Instruments: A Micro-CT Study.

    PubMed

    Yilmaz, Ayca; Helvacioglu-Yigit, Dilek; Gur, Cansu; Ersev, Handan; Kiziltas Sendur, Gullu; Avcu, Egemen; Baydemir, Canan; Abbott, Paul Vincent

    2017-01-01

    The purpose of this study was to compare the incidence and longitudinal propagation of dentin defects after gutta-percha removal with hand and rotary instruments using microcomputed tomography. Twenty mandibular incisors were prepared using the balanced-force technique and scanned in a 19.9  μ m resolution. Following filling with the lateral compaction technique, gutta-percha was removed with ProTaper Universal Retreatment (PTUR) or hand instruments. After rescanning, a total of 24,120 cross-sectional images were analyzed. The numbers, types, and longitudinal length changes of defects were recorded. Defects were observed in 36.90% of the cross sections. A total of 73 defects were comprised of 87.67% craze lines, 2.73% partial cracks, and 9.58% fractures. No significant difference in terms of new defect formation was detected between the retreatment groups. The apical and middle portions of the roots had more dentin defects than the coronal portions. Defects in three roots of the PTUR instrument group increased in length. Under the conditions of this in vitro study, gutta-percha removal seemed to not increase the incidence of dentin defect formation, but the longitudinal defect propagation finding suggests possible cumulative dentinal damage due to additional endodontic procedures. Hand and rotary instrumentation techniques caused similar dentin defect formation during root canal retreatment.

  20. Longitudinal optical monitoring of blood flow in breast tumors during neoadjuvant chemotherapy

    NASA Astrophysics Data System (ADS)

    Cochran, J. M.; Chung, S. H.; Leproux, A.; Baker, W. B.; Busch, D. R.; DeMichele, A. M.; Tchou, J.; Tromberg, B. J.; Yodh, A. G.

    2017-06-01

    We measure tissue blood flow markers in breast tumors during neoadjuvant chemotherapy and investigate their correlation to pathologic complete response in a pilot longitudinal patient study (n  =  4). Tumor blood flow is quantified optically by diffuse correlation spectroscopy (DCS), and tissue optical properties, blood oxygen saturation, and total hemoglobin concentration are derived from concurrent diffuse optical spectroscopic imaging (DOSI). The study represents the first longitudinal DCS measurement of neoadjuvant chemotherapy in humans over the entire course of treatment; it therefore offers a first correlation between DCS flow indices and pathologic complete response. The use of absolute optical properties measured by DOSI facilitates significant improvement of DCS blood flow calculation, which typically assumes optical properties based on literature values. Additionally, the combination of the DCS blood flow index and the tissue oxygen saturation from DOSI permits investigation of tissue oxygen metabolism. Pilot results from four patients suggest that lower blood flow in the lesion-bearing breast is correlated with pathologic complete response. Both absolute lesion blood flow and lesion flow relative to the contralateral breast exhibit potential for characterization of pathological response. This initial demonstration of the combined optical approach for chemotherapy monitoring provides incentive for more comprehensive studies in the future and can help power those investigations.

  1. A methodology for assessing deployment trauma and its consequences in OEF/OIF/OND veterans: The TRACTS longitudinal prospective cohort study

    PubMed Central

    McGlinchey, Regina E.; Milberg, William P.; Fonda, Jennifer R.; Fortier, Catherine Brawn

    2017-01-01

    Many US veterans of Afghanistan and Iraq have multiple physical and psychiatric problems. A major focus of research has been on determining the effects of mild Traumatic Brain Injury (mTBI), but mTBI is rarely diagnosed in the absence of co-occurring conditions such as blast exposure, post-traumatic stress disorder (PTSD), depression, substance abuse, etc. These potentially interactive psychological and physical conditions produce complex patterns of cognitive, psychological, and physical symptoms that impede civilian reintegration and complicate efficient and effective treatment planning. The Translational Research Center for TBI and Stress Disorders (TRACTS) has developed a multidisciplinary approach to the assessment of deployment trauma and its consequences in veterans of these wars. The prospective TRACTS longitudinal cohort study conducts state-of-the-art assessments in the domains of biomedical function, lifetime head trauma, psychological function encompassing deployment experience and lifetime exposure to traumatic events, neuropsychological function, and structural and functional neuroimaging. The TRACTS longitudinal cohort study is the first of its kind to comprehensively evaluate lifetime incidence of TBI and PTSD in these veterans, in addition to those incurred during military deployment. The protocol has begun to reveal information that will help improve understanding of the complex pathophysiology associated with co-occurring mTBI and related stress disorders. PMID:28211592

  2. Longitudinal associations between key dietary behaviors and weight gain over time: Transitions through the adolescent years

    PubMed Central

    Laska, Melissa N.; Murray, David M.; Lytle, Leslie A.; Harnack, Lisa J.

    2012-01-01

    Previous studies have yielded inconsistent results in documenting the association between key dietary factors and adolescent weight change over time. The purpose of this study was to examine the extent to which changes in adolescent sugar-sweetened beverage, diet soda, breakfast and fast food consumption were associated with changes in BMI and percent body fat (PBF), both cross-sectionally and longitudinally. Our sample included 693 Minnesota adolescents followed over two years. Adjusting for physical activity, puberty, race, socio-economic status, age, and total energy intake, cross-sectional findings indicated that for both males and females, diet soda consumption was significantly and positively associated with BMI and PBF, and breakfast intake was significantly and negatively associated with BMI and PBF among girls. In longitudinal analyses, however, there were no significant associations after adjusting for the number of tests performed. This study adds to previous research through its methodological strengths, including adjustment for physical activity and energy intake assessed using state-of-the-art methods (i.e., accelerometers and 24-hour dietary recalls), as well as its evaluation of both BMI and PBF. Additional research is needed to better understand the complex constellation of factors that contribute to adolescent weight gain over time. PMID:21701567

  3. Arithmetic strategy development and its domain-specific and domain-general cognitive correlates: a longitudinal study in children with persistent mathematical learning difficulties.

    PubMed

    Vanbinst, Kiran; Ghesquière, Pol; De Smedt, Bert

    2014-11-01

    Deficits in arithmetic fact retrieval constitute the hallmark of children with mathematical learning difficulties (MLD). It remains, however, unclear which cognitive deficits underpin these difficulties in arithmetic fact retrieval. Many prior studies defined MLD by considering low achievement criteria and not by additionally taking the persistence of the MLD into account. Therefore, the present longitudinal study contrasted children with persistent MLD (MLD-p; mean age: 9 years 2 months) and typically developing (TD) children (mean age: 9 years 6 months) at three time points, to explore whether differences in arithmetic strategy development were associated with differences in numerical magnitude processing, working memory and phonological processing. Our longitudinal data revealed that children with MLD-p had persistent arithmetic fact retrieval deficits at each time point. Children with MLD-p showed persistent impairments in symbolic, but not in nonsymbolic, magnitude processing at each time point. The two groups differed in phonological processing, but not in working memory. Our data indicate that both domain-specific and domain-general cognitive abilities contribute to individual differences in children's arithmetic strategy development, and that the symbolic processing of numerical magnitudes might be a particular risk factor for children with MLD-p. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Initial Cognitive Performance Predicts Longitudinal Aviator Performance

    PubMed Central

    Jo, Booil; Adamson, Maheen M.; Kennedy, Quinn; Noda, Art; Hernandez, Beatriz; Zeitzer, Jamie M.; Friedman, Leah F.; Fairchild, Kaci; Scanlon, Blake K.; Murphy, Greer M.; Taylor, Joy L.

    2011-01-01

    Objectives. The goal of the study was to improve prediction of longitudinal flight simulator performance by studying cognitive factors that may moderate the influence of chronological age. Method. We examined age-related change in aviation performance in aircraft pilots in relation to baseline cognitive ability measures and aviation expertise. Participants were aircraft pilots (N = 276) aged 40–77.9. Flight simulator performance and cognition were tested yearly; there were an average of 4.3 (± 2.7; range 1–13) data points per participant. Each participant was classified into one of the three levels of aviation expertise based on Federal Aviation Administration pilot proficiency ratings: least, moderate, or high expertise. Results. Addition of measures of cognitive processing speed and executive function to a model of age-related change in aviation performance significantly improved the model. Processing speed and executive function performance interacted such that the slowest rate of decline in flight simulator performance was found in aviators with the highest scores on tests of these abilities. Expertise was beneficial to pilots across the age range studied; however, expertise did not show evidence of reducing the effect of age. Discussion. These data suggest that longitudinal performance on an important real-world activity can be predicted by initial assessment of relevant cognitive abilities. PMID:21586627

  5. Language Awareness and Perception of Connected Speech in a Second Language

    ERIC Educational Resources Information Center

    Kennedy, Sara; Blanchet, Josée

    2014-01-01

    To be effective second or additional language (L2) listeners, learners should be aware of typical processes in connected L2 speech (e.g. linking). This longitudinal study explored how learners' developing ability to perceive connected L2 speech was related to the quality of their language awareness. Thirty-two learners of L2 French at a university…

  6. Shared Book Reading and Preschool Children's Academic Achievement: Evidence from the Early Childhood Longitudinal Study-Birth Cohort

    ERIC Educational Resources Information Center

    Barnes, Erica; Puccioni, Jaime

    2017-01-01

    This paper examines the relationships among the quality and quantity of parent-child shared book reading (SBR) engagements and children's reading and mathematics outcomes in preschool. Additionally, we explore how child and family characteristics predict the quality and quantity of SBR. Quantity was measured using parental reports of the frequency…

  7. Physical Inactivity from Adolescence to Young Adulthood: The Relevance of Various Dimensions of Inequality in a Swedish Longitudinal Sample

    ERIC Educational Resources Information Center

    Wells, Laura; Nermo, Magnus; Östberg, Viveca

    2017-01-01

    As physical inactivity may track from adolescence to adulthood, it is important to identify social determinants of physical inactivity in early life. However, most studies have measured socioeconomic position as one dimension. We examine whether multiple dimensions of socioeconomic position, in addition to other dimensions of inequality (i.e.,…

  8. Resident Father-Child Involvement: Associations with Young Children's Social Development and Kindergarten Readiness in the ECLS-B

    ERIC Educational Resources Information Center

    Meece, Darrell

    2013-01-01

    The current investigation examined continuity from 9-months to 4-years of age in father-child interaction in instrumental child care activities, as well as enrichment and play activities, using data collected from 8,450 children with residential fathers included in the Early Childhood Longitudinal Study, Birth Cohort (ECLS-B). Additionally, social…

  9. Building on the Data and Adding to the Discussion: The Experiences and Outcomes of Students with Emotional Disturbance

    ERIC Educational Resources Information Center

    Bradley, Renee; Doolittle, Jennifer; Bartolotta, Robert

    2008-01-01

    The purpose of this article is to add to the discussion regarding identification of students with emotional and behavioral disorders (EBD). In addition, the article discusses services that students with EBD receive and their outcomes. The article reviews data from several national longitudinal studies to present a comprehensive picture of issues…

  10. Stability and Decline in Gross Motor Function among Children and Youth with Cerebral Palsy Aged 2 to 21 Years

    ERIC Educational Resources Information Center

    Hanna, Steven E.; Rosenbaum, Peter L.; Bartlett, Doreen J.; Palisano, Robert J.; Walter, Stephen D.; Avery, Lisa; Russell, Dianne J.

    2009-01-01

    This paper reports the construction of gross motor development curves for children and youth with cerebral palsy (CP) in order to assess whether function is lost during adolescence. We followed children previously enrolled in a prospective longitudinal cohort study for an additional 4 years, as they entered adolescence and young adulthood. The…

  11. Language in the Transition from Home to School. Final Report to the Nuffield Foundation.

    ERIC Educational Resources Information Center

    Wells, Gordon; French, Peter

    A longitudinal study of language development in the preschool years was conducted in order to describe developmental sequence and to estimate, at three-month intervals, the range of language attainment in a normal population of children between 15 and 60 months of age. Additionally, possible determinants of variation in rate and style of language…

  12. Negotiating the Complementarian Gender Ideology of an Evangelical Student Subculture: Further Evidence from Women's Narratives

    ERIC Educational Resources Information Center

    Bryant, Alyssa N.

    2009-01-01

    This study is based on a longitudinal, qualitative investigation of a burgeoning evangelical student organisation on a university campus in the USA. In addition to four months of observation, in-depth interviews were conducted with students in their first and third years of college to understand the gender climate and ideology that characterised…

  13. Effects of an Additional Mathematics Content Course on Elementary Teachers' Mathematical Beliefs and Knowledge for Teaching

    ERIC Educational Resources Information Center

    Smith, Marvin E.; Swars, Susan L.; Smith, Stephanie Z.; Hart, Lynn C.; Haardorfer, Regine

    2012-01-01

    This longitudinal study examines the effects of changes in an elementary teacher preparation program on mathematics beliefs and content knowledge for teaching of two groups of prospective teachers (N = 276): (1) those who completed a program with three mathematics content courses and two mathematics methods courses and (2) those who completed a…

  14. Estimating search engine index size variability: a 9-year longitudinal study.

    PubMed

    van den Bosch, Antal; Bogers, Toine; de Kunder, Maurice

    One of the determining factors of the quality of Web search engines is the size of their index. In addition to its influence on search result quality, the size of the indexed Web can also tell us something about which parts of the WWW are directly accessible to the everyday user. We propose a novel method of estimating the size of a Web search engine's index by extrapolating from document frequencies of words observed in a large static corpus of Web pages. In addition, we provide a unique longitudinal perspective on the size of Google and Bing's indices over a nine-year period, from March 2006 until January 2015. We find that index size estimates of these two search engines tend to vary dramatically over time, with Google generally possessing a larger index than Bing. This result raises doubts about the reliability of previous one-off estimates of the size of the indexed Web. We find that much, if not all of this variability can be explained by changes in the indexing and ranking infrastructure of Google and Bing. This casts further doubt on whether Web search engines can be used reliably for cross-sectional webometric studies.

  15. Phonological Awareness and Rapid Automatized Naming Predicting Early Development in Reading and Spelling: Results from a Cross-Linguistic Longitudinal Study

    PubMed Central

    Furnes, Bjarte; Samuelsson, Stefan

    2010-01-01

    In this study, the relationship between latent constructs of phonological awareness (PA) and rapid automatized naming (RAN) were investigated and related to later measures of reading and spelling in children learning to read in different alphabetic writing systems (i.e., Norwegian/Swedish vs. English). 750 U.S./Australian children and 230 Scandinavian children were followed longitudinally between kindergarten and 2nd grade. PA and RAN were measured in kindergarten and Grade 1, while word recognition, phonological decoding, and spelling were measured in kindergarten, Grade 1, and Grade 2. In general, high stability was observed for the various reading and spelling measures, such that little additional variance was left open for PA and RAN. However, results demonstrated that RAN was more related to reading than spelling across orthographies, with the opposite pattern shown for PA. In addition, tests of measurement invariance show that the factor loadings of each observed indicator on the latent PA factor was the same across U.S./Australia and Scandinavia. Similar findings were obtained for RAN. In general, tests of structural invariance show that models of early literacy development are highly transferable across languages. PMID:21359098

  16. Investigation of a rotary ultrasonic motor using a longitudinal vibrator and spiral fin rotor.

    PubMed

    Peng, Taijiang; Wu, Xiaoyu; Liang, Xiong; Shi, Hongyan; Luo, Feng

    2015-08-01

    A Langevin transducer can provide longitudinal vibration with larger amplitude while also possessing a greater fatigue life than other types of piezoelectric vibrators. A novel rotary Ultrasonic Motor (USM) was proposed based on the use of a longitudinal transducer (acting as the stator) and a spiral fin rotor: the front cover of the Langevin transducer was designed as a double-layer cup-shaped structure, with the rotor sustained by the inner-layer, and the bearing cover fixed to the outer-layer; the rotor consisted of a shaft and spiral fins which acted as the elastic coupler. It is different from a traditional traveling USM, because the stator provides longitudinal vibration and the rotor generates the elliptical motion. This paper analyzed the motion locus equation of the fin contact points. Additionally, a theoretical analysis was performed in regards to the mechanism and the motor's rotor motion characteristics, which demonstrates the relationships among the motor's driving force, the torque, the revolution speed, and the motor structure parameters. A motor prototype has been manufactured and surveyed to demonstrate the motor performance. The relationships between the amplitude and the preload on the rotor, the free revolution speed, and the torque of the motor have also been studied. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Predictors for Physical Activity in Adolescent Girls Using Statistical Shrinkage Techniques for Hierarchical Longitudinal Mixed Effects Models

    PubMed Central

    Grant, Edward M.; Young, Deborah Rohm; Wu, Tong Tong

    2015-01-01

    We examined associations among longitudinal, multilevel variables and girls’ physical activity to determine the important predictors for physical activity change at different adolescent ages. The Trial of Activity for Adolescent Girls 2 study (Maryland) contributed participants from 8th (2009) to 11th grade (2011) (n=561). Questionnaires were used to obtain demographic, and psychosocial information (individual- and social-level variables); height, weight, and triceps skinfold to assess body composition; interviews and surveys for school-level data; and self-report for neighborhood-level variables. Moderate to vigorous physical activity minutes were assessed from accelerometers. A doubly regularized linear mixed effects model was used for the longitudinal multilevel data to identify the most important covariates for physical activity. Three fixed effects at the individual level and one random effect at the school level were chosen from an initial total of 66 variables, consisting of 47 fixed effects and 19 random effects variables, in additional to the time effect. Self-management strategies, perceived barriers, and social support from friends were the three selected fixed effects, and whether intramural or interscholastic programs were offered in middle school was the selected random effect. Psychosocial factors and friend support, plus a school’s physical activity environment, affect adolescent girl’s moderate to vigorous physical activity longitudinally. PMID:25928064

  18. A longitudinal study of multidimensional performance characteristics related to physical capacities in youth handball.

    PubMed

    Matthys, Stijn P J; Vaeyens, Roel; Fransen, Job; Deprez, Dieter; Pion, Johan; Vandendriessche, Joric; Vandorpe, Barbara; Lenoir, Matthieu; Philippaerts, Renaat

    2013-01-01

    Longitudinal research provides valuable information about change and progress towards elite performance. Unfortunately, there is a lack of longitudinal research in handball. In this study, 94 youth handball players (oldest group: n = 41; age 15-17 and youngest group: n = 53; age 13-15) were followed over a three-year period. Repeated measures ANCOVA was conducted to reveal longitudinal changes in anthropometry and physical performance between elite and non-elite players, controlling for maturation. Maturation effects were found for anthropometry (P < 0.01) and some physical performance measures in strength and speed (P < 0.05). The lack of significant interaction effects revealed that during the three years of the study the elite players did not improve their physical performance more rapidly than the non-elites. Furthermore, they had a similar anthropometric profile to the non-elites. Elite players performed better on the Yo-Yo Intermittent Recovery test (P < 0.01; on average 24.0 in the youngest group and 25.2% in the oldest group over the three years) and on the speed and coordination items (P < 0.05; shuttle run: 3.6 and 5.1%; cross hopping: 11.0 and 14.8%, handball-specific shuttle run: 7.6 and 7.7%; slalom dribble test: 10.7 and 8.9%; sprint 30 m: 4.9 and 3.9%). Additionally, Yo-Yo performance and coordination with and without a ball were the most discriminating factors between the playing levels. In conclusion, youth coaches and scouts within team handball should recognise the importance of good skills and an excellent endurance for talent identification purposes.

  19. Pathways from assaultive violence to post-traumatic stress, depression, and generalized anxiety symptoms through stressful life events: longitudinal mediation models.

    PubMed

    Lowe, S R; Joshi, S; Galea, S; Aiello, A E; Uddin, M; Koenen, K C; Cerdá, M

    2017-10-01

    Assaultive violence events are associated with increased risk for adverse psychiatric outcomes, including post-traumatic stress (PTS), depression, and generalized anxiety. Prior research has indicated that economic, legal, and social stressors that could follow assaultive events may explain the increased risk for adverse psychiatric outcomes, yet longitudinal studies have not adequately examined this pathway. In the current study, we aimed to address this limitation. Participants (N = 1360) were part of a longitudinal population-based study of adults living in Detroit. At three waves, participants indicated their exposure to assaultive violence and economic, legal, and social stressors, and completed inventories of PTS, depression, and generalized anxiety. Longitudinal mediation models were used to test the hypothesized pathway from assaultive violence to each psychiatric outcome. The hypothesized models evidenced good fit with the data and, in each, the paths from Wave 1 (W1) assaultive violence to W2 stressors, and from W2 stressors to W3 symptoms were significant (range of Standardized Estimates: 0.09-0.15, all p < 0.01). Additionally, the indirect paths from W1 assaultive violence to W3 symptoms were significant (range of Standardized Estimates: 0.01-0.02, all p < 0.05). The findings illustrate that the economic, legal, and social stressors that could follow assaultive violence increase risk for a range of psychiatric symptoms. Although future research is needed, the results suggest that investment in interventions that prevent and mitigate assaultive violence survivors' exposure to such stressors may be an effective way to prevent mental illness in the aftermath of violent assaults.

  20. Crohn's disease in Japan: diagnostic criteria and epidemiology.

    PubMed

    Yao, T; Matsui, T; Hiwatashi, N

    2000-10-01

    New diagnostic criteria for Crohn's disease and a review of Japanese epidemiologic studies are presented. New diagnostic criteria for Crohn's disease were established by the Research Committee of Inflammatory Bowel Disease, set up by the Japanese Ministry of Health and Welfare. For a definite diagnosis one of the following three conditions is required: 1) longitudinal ulcer or luminal deformity induced by longitudinal ulcer or cobblestone pattern, 2) intestinal small aphthous ulcerations arranged in a longitudinal fashion for at least three months plus noncaseating granulomas, and 3) multiple small aphthous ulcerations in both the upper and lower digestive tract not necessarily with longitudinal arrangement, for at least three months, plus noncaseating granulomas. Moreover, ulcerative colitis, ischemic enterocolitis, and acute infectious enterocolitis should be excluded. Data from the Japanese Ministry of Health and Welfare, in addition to data collected from two study groups, these being the two largest studies in Japan, are reviewed with regard to epidemiology. The number of patients with Crohn's disease has increased remarkably. The prevalence and the annual incidence of patients with Crohn's disease in Japan were estimated to be approximately 2.9 and 0.6 per 10(5) population in 1986, respectively, and 13.5 and 1.2 per 10(5) population in 1998. Characteristic features of Crohn's disease in Japan are that the male-female ratio exceeds 2, and that there is no second peak of incidence in the age group of 55 to 65 years. Clinically, Crohn's disease with only multiple small aphthous ulcerations, which is the earliest stage of the disease that is diagnosable, was found in 5 percent of patients.

  1. Attrition Bias Related to Missing Outcome Data: A Longitudinal Simulation Study.

    PubMed

    Lewin, Antoine; Brondeel, Ruben; Benmarhnia, Tarik; Thomas, Frédérique; Chaix, Basile

    2018-01-01

    Most longitudinal studies do not address potential selection biases due to selective attrition. Using empirical data and simulating additional attrition, we investigated the effectiveness of common approaches to handle missing outcome data from attrition in the association between individual education level and change in body mass index (BMI). Using data from the two waves of the French RECORD Cohort Study (N = 7,172), we first examined how inverse probability weighting (IPW) and multiple imputation handled missing outcome data from attrition in the observed data (stage 1). Second, simulating additional missing data in BMI at follow-up under various missing-at-random scenarios, we quantified the impact of attrition and assessed how multiple imputation performed compared to complete case analysis and to a perfectly specified IPW model as a gold standard (stage 2). With the observed data in stage 1, we found an inverse association between individual education and change in BMI, with complete case analysis, as well as with IPW and multiple imputation. When we simulated additional attrition under a missing-at-random pattern (stage 2), the bias increased with the magnitude of selective attrition, and multiple imputation was useless to address it. Our simulations revealed that selective attrition in the outcome heavily biased the association of interest. The present article contributes to raising awareness that for missing outcome data, multiple imputation does not do better than complete case analysis. More effort is thus needed during the design phase to understand attrition mechanisms by collecting information on the reasons for dropout.

  2. Functional Additive Mixed Models

    PubMed Central

    Scheipl, Fabian; Staicu, Ana-Maria; Greven, Sonja

    2014-01-01

    We propose an extensive framework for additive regression models for correlated functional responses, allowing for multiple partially nested or crossed functional random effects with flexible correlation structures for, e.g., spatial, temporal, or longitudinal functional data. Additionally, our framework includes linear and nonlinear effects of functional and scalar covariates that may vary smoothly over the index of the functional response. It accommodates densely or sparsely observed functional responses and predictors which may be observed with additional error and includes both spline-based and functional principal component-based terms. Estimation and inference in this framework is based on standard additive mixed models, allowing us to take advantage of established methods and robust, flexible algorithms. We provide easy-to-use open source software in the pffr() function for the R-package refund. Simulations show that the proposed method recovers relevant effects reliably, handles small sample sizes well and also scales to larger data sets. Applications with spatially and longitudinally observed functional data demonstrate the flexibility in modeling and interpretability of results of our approach. PMID:26347592

  3. Functional Additive Mixed Models.

    PubMed

    Scheipl, Fabian; Staicu, Ana-Maria; Greven, Sonja

    2015-04-01

    We propose an extensive framework for additive regression models for correlated functional responses, allowing for multiple partially nested or crossed functional random effects with flexible correlation structures for, e.g., spatial, temporal, or longitudinal functional data. Additionally, our framework includes linear and nonlinear effects of functional and scalar covariates that may vary smoothly over the index of the functional response. It accommodates densely or sparsely observed functional responses and predictors which may be observed with additional error and includes both spline-based and functional principal component-based terms. Estimation and inference in this framework is based on standard additive mixed models, allowing us to take advantage of established methods and robust, flexible algorithms. We provide easy-to-use open source software in the pffr() function for the R-package refund. Simulations show that the proposed method recovers relevant effects reliably, handles small sample sizes well and also scales to larger data sets. Applications with spatially and longitudinally observed functional data demonstrate the flexibility in modeling and interpretability of results of our approach.

  4. Healthy brain connectivity predicts atrophy progression in non-fluent variant of primary progressive aphasia.

    PubMed

    Mandelli, Maria Luisa; Vilaplana, Eduard; Brown, Jesse A; Hubbard, H Isabel; Binney, Richard J; Attygalle, Suneth; Santos-Santos, Miguel A; Miller, Zachary A; Pakvasa, Mikhail; Henry, Maya L; Rosen, Howard J; Henry, Roland G; Rabinovici, Gil D; Miller, Bruce L; Seeley, William W; Gorno-Tempini, Maria Luisa

    2016-10-01

    Neurodegeneration has been hypothesized to follow predetermined large-scale networks through the trans-synaptic spread of toxic proteins from a syndrome-specific epicentre. To date, no longitudinal neuroimaging study has tested this hypothesis in vivo in frontotemporal dementia spectrum disorders. The aim of this study was to demonstrate that longitudinal progression of atrophy in non-fluent/agrammatic variant primary progressive aphasia spreads over time from a syndrome-specific epicentre to additional regions, based on their connectivity to the epicentre in healthy control subjects. The syndrome-specific epicentre of the non-fluent/agrammatic variant of primary progressive aphasia was derived in a group of 10 mildly affected patients (clinical dementia rating equal to 0) using voxel-based morphometry. From this region, the inferior frontal gyrus (pars opercularis), we derived functional and structural connectivity maps in healthy controls (n = 30) using functional magnetic resonance imaging at rest and diffusion-weighted imaging tractography. Graph theory analysis was applied to derive functional network features. Atrophy progression was calculated using voxel-based morphometry longitudinal analysis on 34 non-fluent/agrammatic patients. Correlation analyses were performed to compare volume changes in patients with connectivity measures of the healthy functional and structural speech/language network. The default mode network was used as a control network. From the epicentre, the healthy functional connectivity network included the left supplementary motor area and the prefrontal, inferior parietal and temporal regions, which were connected through the aslant, superior longitudinal and arcuate fasciculi. Longitudinal grey and white matter changes were found in the left language-related regions and in the right inferior frontal gyrus. Functional connectivity strength in the healthy speech/language network, but not in the default network, correlated with longitudinal grey matter changes in the non-fluent/agrammatic variant of primary progressive aphasia. Graph theoretical analysis of the speech/language network showed that regions with shorter functional paths to the epicentre exhibited greater longitudinal atrophy. The network contained three modules, including a left inferior frontal gyrus/supplementary motor area, which was most strongly connected with the epicentre. The aslant tract was the white matter pathway connecting these two regions and showed the most significant correlation between fractional anisotropy and white matter longitudinal atrophy changes. This study showed that the pattern of longitudinal atrophy progression in the non-fluent/agrammatic variant of primary progressive aphasia relates to the strength of connectivity in pre-determined functional and structural large-scale speech production networks. These findings support the hypothesis that the spread of neurodegeneration occurs by following specific anatomical and functional neuronal network architectures. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. Longitudinal motor development of "apparently normal" high-risk infants at 18 months, 3 and 5 years.

    PubMed

    Goyen, Traci Anne; Lui, Kei

    2002-12-01

    Motor development appears to be more affected by premature birth than other developmental domains, however few studies have specifically investigated the development of gross and fine motor skills in this population. To examine longitudinal motor development in a group of "apparently normal" high-risk infants. Developmental follow-up clinic in a perinatal centre. Longitudinal observational cohort study. Fifty-eight infants born less than 29 weeks gestation and/or 1000 g and without disabilities detected at 12 months. Longitudinal gross and fine motor skills at 18 months, 3 and 5 years using the Peabody Developmental Motor Scales. The HOME scale provided information of the home environment as a stimulus for development. A large proportion (54% at 18 months, 47% at 3 years and 64% at 5 years) of children continued to have fine motor deficits from 18 months to 5 years. The proportion of infants with gross motor deficits significantly increased over this period (14%, 33% and 81%, p<0.001), particularly for the 'micropreemies' (born <750 g). In multivariate analyses, gross motor development was positively influenced by the quality of the home environment. A large proportion of high-risk infants continued to have fine motor deficits, reflecting an underlying problem with fine motor skills. The proportion of infants with gross motor deficits significantly increased, as test demands became more challenging. In addition, the development of gross and fine motor skills appears to be influenced differently by the home environment.

  6. Mixed models approaches for joint modeling of different types of responses.

    PubMed

    Ivanova, Anna; Molenberghs, Geert; Verbeke, Geert

    2016-01-01

    In many biomedical studies, one jointly collects longitudinal continuous, binary, and survival outcomes, possibly with some observations missing. Random-effects models, sometimes called shared-parameter models or frailty models, received a lot of attention. In such models, the corresponding variance components can be employed to capture the association between the various sequences. In some cases, random effects are considered common to various sequences, perhaps up to a scaling factor; in others, there are different but correlated random effects. Even though a variety of data types has been considered in the literature, less attention has been devoted to ordinal data. For univariate longitudinal or hierarchical data, the proportional odds mixed model (POMM) is an instance of the generalized linear mixed model (GLMM; Breslow and Clayton, 1993). Ordinal data are conveniently replaced by a parsimonious set of dummies, which in the longitudinal setting leads to a repeated set of dummies. When ordinal longitudinal data are part of a joint model, the complexity increases further. This is the setting considered in this paper. We formulate a random-effects based model that, in addition, allows for overdispersion. Using two case studies, it is shown that the combination of random effects to capture association with further correction for overdispersion can improve the model's fit considerably and that the resulting models allow to answer research questions that could not be addressed otherwise. Parameters can be estimated in a fairly straightforward way, using the SAS procedure NLMIXED.

  7. Specificity of the Association between Marital Discord and Longitudinal Changes in Symptoms of Depression and Generalized Anxiety Disorder in the Irish Longitudinal Study on Ageing.

    PubMed

    Whisman, Mark A; Robustelli, Briana L; Labrecque, Lindsay T

    2018-03-25

    This longitudinal study was conducted to evaluate actor and partner effects of marital discord on changes in symptoms of depression and generalized anxiety disorder (GAD) in a large population sample of Irish adults (N = 1,445 couples), adjusting for the potential confounds of quality of other social relationships and other psychopathology symptoms. The Actor-Partner Interdependence Model was used to examine actor and partner effects of marital discord on changes in symptoms of depression and GAD at a 2-year follow-up. Additional models examined these associations adjusting for family and friend discord and symptoms of the other type of psychopathology (depressive or GAD symptoms). Actor effects of marital discord on depressive and anxiety symptoms were greater for men than for women. There were significant, positive actor effects of marital discord on depressive symptoms for husbands and wives, which remained significant when adjusting for family and friend discord and GAD symptoms. There were significant, positive actor effects of marital discord on GAD symptoms for husbands, which remained significant when adjusting for family and friend discord and depressive symptoms. Results demonstrate that longitudinal associations between marital discord and depressive symptoms (for wives and husbands) and GAD symptoms (for husbands) are incremental to other rival explanations (family and friend discord and the other set of symptoms). Findings provide evidence for a potential causal association leading from marital discord to symptoms of depression and GAD. © 2018 Family Process Institute.

  8. The Influence of Financial, Cultural and Social Capital on the Likelihood of Success of Community College Students: A Quantitative Study Utilizing the Education Longitudinal Study of 2002-2012

    ERIC Educational Resources Information Center

    Iffland, Aaron R.

    2016-01-01

    Community colleges are an integral part of the postsecondary education system in the United States. Unfortunately, college completion rates continue to decline. Additionally, median income in the United States is also declining. The idea that each successive generation of students will do better than the previous one is quickly becoming a fantasy.…

  9. [Logistics of collection and transportation of biological samples and the organization of the central laboratory in the ELSA-Brasil].

    PubMed

    Fedeli, Ligia G; Vidigal, Pedro G; Leite, Claudia Mendes; Castilhos, Cristina D; Pimentel, Robércia Anjos; Maniero, Viviane C; Mill, Jose Geraldo; Lotufo, Paulo A; Pereira, Alexandre C; Bensenor, Isabela M

    2013-06-01

    The ELSA (Estudo Longitudinal de Saúde do Adulto - Brazilian Longitudinal Study for Adult Health) is a multicenter cohort study which aims at the identification of risk factors associated with type 2 diabetes and cardiovascular diseases in the Brazilian population. The paper describes the strategies for the collection, processing, transportation, and quality control of blood and urine tests in the ELSA. The study decided to centralize the tests at one single laboratory. The processing of the samples was performed at the local laboratories, reducing the weight of the material to be transported, and diminishing the costs of transportation to the central laboratory at the Universidade de São Paulo Hospital. The study included tests for the evaluation of diabetes, insulin resistance, dyslipidemia, electrolyte abnormalities, thyroid hormones, uric acid, hepatic enzyme abnormalities, inflammation, and total blood cell count. In addition, leukocyte DNA, urine, plasma and serum samples were stored. The central laboratory performed approximately 375,000 tests.

  10. Longitudinal study of dogs living in an area of Spain highly endemic for leishmaniasis by serologic analysis and the leishmanin skin test.

    PubMed

    Solano-Gallego, Laia; Llull, Joan; Ramis, Antonio; Fernández-Bellon, Hugo; Rodríguez, Alhelí; Ferrer, Lluís; Alberola, Jordi

    2005-06-01

    The literature contains few longitudinal studies that have assessed areas endemic for canine leishmaniasis and over the same time interval Leishmania-specific cellular and humoral immunity in healthy dogs. Fourteen dogs, three mixed breed and 11 Ibizian hounds, living in an area of Spain that was highly endemic for leishmaniasis were followed-up over a three-year period by serologic analysis and the leishmanin skin test (LST). All but one of these dogs remained clinically healthy during the study period. Seroconversion was observed in four dogs. The three mixed breed dogs had a negative reaction in the LST in the first and third years. The general trend in the Ibizian hounds was an increase in the diameter of the LST reaction at both the 48- and 72-hour readings in the third year. This study demonstrates that in addition to an increase in Leishmania-specific humoral immune response in Ibizian hounds, a parallel increase in cellular immune response was observed.

  11. Academic Performance of Language-Minority Students and All-Day Kindergarten: A Longitudinal Study

    ERIC Educational Resources Information Center

    Chang, Mido

    2012-01-01

    This longitudinal study examined the effect of all-day kindergarten programs on the academic achievement of students from racial language minority and low socioeconomic class. The study employed a series of 3-level longitudinal multilevel analyses using a nationally representative database, the Early Childhood Longitudinal Study (ECLS). The study…

  12. Childhood gender-typed behavior and adolescent sexual orientation: A longitudinal population-based study.

    PubMed

    Li, Gu; Kung, Karson T F; Hines, Melissa

    2017-04-01

    Lesbian and gay individuals have been reported to show more interest in other-sex, and/or less interest in same-sex, toys, playmates, and activities in childhood than heterosexual counterparts. Yet, most of the relevant evidence comes from retrospective studies or from prospective studies of clinically referred, extremely gender nonconforming children. In addition, findings are mixed regarding the relation between childhood gender-typed behavior and the later sexual orientation spectrum from exclusively heterosexual to exclusively lesbian/gay. The current study drew a sample (2,428 girls and 2,169 boys) from a population-based longitudinal study, and found that the levels of gender-typed behavior at ages 3.5 and 4.75 years, although less so at age 2.5 years, significantly and consistently predicted adolescents' sexual orientation at age 15 years, both when sexual orientation was conceptualized as 2 groups or as a spectrum. In addition, within-individual change in gender-typed behavior during the preschool years significantly related to adolescent sexual orientation, especially in boys. These results suggest that the factors contributing to the link between childhood gender-typed behavior and sexual orientation emerge during early development. Some of those factors are likely to be nonsocial, because nonheterosexual individuals appear to diverge from gender norms regardless of social encouragement to conform to gender roles. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  13. Neuropsychiatric and cardiometabolic comorbidities in patients with previously diagnosed Cushing's disease: a longitudinal observational study.

    PubMed

    Dimopoulou, C; Geraedts, V; Stalla, G K; Sievers, C

    2015-03-27

    Only few studies have systematically investigated neuropsychiatric aspects in patients with Cushing's disease (CD). Pain syndromes have been described in patients with pituitary adenomas, but so far no systematical investigation has been conducted in patients with CD. Additionally, CD has an association with cardiometabolic comorbidities which ultimately leads to increased morbidity and mortality. Long-term treatment of the hypercortisolic state cannot prevent the persistence of an unfavourable cardiometabolic risk profile. Finally, chronic hypercortisolism is known to impact the health-related quality of life (HRQoL). We aim to systematically investigate the neuropsychiatric and cardiometabolic comorbidities, as well as assess the HRQoL, in patients with previously diagnosed CD in a longitudinal fashion. In this longitudinal study, we will assess 20 patients with CD displaying biochemical control 24 months after recruitment in the initial cross-sectional study (n=80). This will be a mixed cohort including patients after surgical, after radiation therapy and/or under current medical treatment for CD. Primary outcomes include changes in mean urinary free cortisol and changes in specific pain patterns. Secondary/exploratory neuropsychiatric domains include depression, anxiety, personality, sleep, body image and quality of life. Secondary/exploratory cardiometabolic domains include anthropometric parameters, cardiometabolic risk biomarkers and insulin resistance. Additional domains will be investigated if warranted by clinical indication. Safety assessment under medical therapy will include liver enzymes, ECG abnormalities and hyperglycaemia. Risk of damage from study-conditioned measures is very small and considered ethically justified. Dual-energy X-ray absorptiometry may call for detailed fracture risk assessment. However, the radiation dose is very small and only administered on clinical indication; therefore, it is considered ethically justified. This protocol has been approved by the local medical ethics committee. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  14. Efficacy Expectations and Vocational Interests as Mediators between Sex and Choice of Math/Science College Majors: A Longitudinal Study

    PubMed

    Lapan; Shaughnessy; Boggs

    1996-12-01

    A longitudinal study was conducted to test the mediational role of efficacy expectations in relation to sex differences in the choice of a math/science college major. Data on 101 students were gathered prior to their entering college and then again after they had declared a major 3 years later. Path analytic results support the importance of both math self-efficacy beliefs and vocational interest in mathematics in predicting entry into math/science majors and mediating sex differences in these decisions. Also, students who described themselves as more extroverted were less likely to take additional math classes in high school. Students with stronger artistic vocational interests chose majors less related to math and science. School personnel are strongly encouraged to develop programs that challenge the crystallization of efficacy beliefs and vocational interest patterns before students enter college.

  15. Rumination mediates the prospective effect of low self-esteem on depression: a five-wave longitudinal study.

    PubMed

    Kuster, Farah; Orth, Ulrich; Meier, Laurenz L

    2012-06-01

    Previous research supports the vulnerability model of low self-esteem and depression, which states that low self-esteem operates as a prospective risk factor for depression. However, it is unclear which processes mediate the effect of low self-esteem. To test for the mediating effect of rumination, the authors used longitudinal mediation models, which included exclusively prospective effects and controlled for autoregressive effects of the constructs. Data came from 663 individuals (aged 16 to 62 years), who were assessed 5 times over an 8-month period. The results indicated that low self-esteem predicted subsequent rumination, which in turn predicted subsequent depression, and that rumination partially mediated the prospective effect of low self-esteem on depression. These findings held for both men and women, and for both affective-cognitive and somatic symptoms of depression. Future studies should test for the mediating effects of additional intrapersonal and interpersonal processes.

  16. A longitudinal study of hearing and middle ear status of individuals with cleft palate with and without additional malformations/syndromes.

    PubMed

    Flynn, Traci; Persson, Christina; Moller, Claes; Lohmander, Anette; Magnusson, Lennart

    2014-09-01

    Objective : To describe and compare the middle ear status and hearing sensitivity in adolescence with isolated cleft palate plus additional malformations and/or syndromes with those with only an isolated cleft palate. Design : Retrospective and longitudinal. Two groups of individuals with isolated cleft palate were compared. Participants : A cohort of individuals born over 4 years in the western region of Sweden. The cohort was divided into one group with isolated cleft palate (n = 31; ICP) and one group with isolated cleft palate plus additional malformations and/or syndromes (n = 37; ICP+). Methods : Middle ear status and hearing thresholds were collected from the medical records at 7, 10, 13, and 16 years of age, examined, and compared within and between groups over time. Results : The ICP+ group demonstrated a significantly higher prevalence of abnormal middle ear status and elevated hearing thresholds as compared with the ICP group. As the individuals aged, the prevalence of abnormal middle ear status decreased. The hearing levels in both groups decreased in the low to middle frequencies as individuals aged; however, the hearing in the high frequencies did not. Conclusions : Individuals with cleft palate need to be followed routinely for middle ear status and hearing thresholds to ensure optimal audiological rehabilitation, with particular attention to those with additional malformations and/or syndromes.

  17. Effects of a school reform on longitudinal stability of students' preferences with regard to education.

    PubMed

    Könings, Karen D; Brand-Gruwel, Saskia; Elen, Jan

    2012-09-01

    Students' perspective on education is of crucial importance for its effectivity, but students' opinions are seldom acknowledged by teachers and designers. Student participation in the educational design process could be a suitable tool to better take students' preferences into account. However, for effective participatory design, it is necessary to know whether students have stable preferences for the design of their education. Changeability of preferences would require a more continuing design process allowing continuous adaptations. This longitudinal survey study aimed to determine the changeability over time of students' preferences for different aspects of a learning environment. Additionally, causes of possible changes in preferences are investigated. The participants were 1,335 high school students of five schools for secondary education in the Netherlands, joining this study during a period of 2 years. Data about students' preferences were collected at three moments, using the Inventory of Perceived Study Environment Extended. Learning-related student characteristics, such as processing strategies and motivational orientations, were measured with the Inventory of Learning Styles. Additionally, data on learning performances were collected. The results showed stability on preferences for almost all studied characteristics of the learning environment. Particularly remarkable was a drop in desirability for student autonomy. This was larger for students with a certificate-oriented motivation and smaller for self-regulated students. Additionally, poorly performing students had a larger decrease in preference for autonomy. The stability on most aspects supports that participatory design might result in fairly stable instructional designs, although caution is needed with respect to student autonomy. ©2011 The British Psychological Society.

  18. Estimation of True Change with Three-Wave Data.

    ERIC Educational Resources Information Center

    Gupta, J. K.; And Others

    1988-01-01

    A multiple regression model for estimating true change of an individual by using information in addition to pretest-posttest data is described. Longitudinal panel or multi-wave data taken between the pretest and the posttest constitute the additional information. (TJH)

  19. Interrelations between executive function and symptoms of hyperactivity/impulsivity and inattention in preschoolers: a two year longitudinal study.

    PubMed

    Brocki, Karin C; Eninger, Lilianne; Thorell, Lisa B; Bohlin, Gunilla

    2010-02-01

    The present study, including children at risk for developing Attention Deficit Hyperactivity Disorder (ADHD), examined the idea that complex executive functions (EFs) build upon more simple ones. This notion was applied in the study of longitudinal interrelations between core EF components - simple and complex inhibition, selective attention, and working memory (WM) - at age 5 and 6 as well as their predictive relations to ADHD symptoms at age 7. The results showed that simple inhibition and selective attention at age 5 independently predicted complex inhibition and WM at age 6. In addition, EFs primarily predicted symptoms of inattention rather than hyperactivity/impulsivity even at this young age. Finally, age 6 complex inhibition was shown to act as a mediator in the relations between simple inhibition and selective attention at age 5 and symptoms of inattention at age 7. These findings provide novel longitudinal support for the theory that fundamental EF components show a progression with age toward more complex executive control (see Garon et al. Psychological Bulletin 134(1):31-60 2008). Further, complex inhibition, implicating both inhibition and WM, seems to be a particularly strong correlate of ADHD symptoms in young children and should as such be the focus of future studies examining the relation between cognitive function and ADHD symptoms from a developmental perspective.

  20. 77 FR 39344 - Agency Information (Post-9/11 GI Bill Education Longitudinal Study Survey) Activity Under OMB Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-02

    ... DEPARTMENT OF VETERANS AFFAIRS [OMB Control No. 2900-New (Post-9/11 GI Bill Longitudinal Study Survey)] Agency Information (Post-9/11 GI Bill Education Longitudinal Study Survey) Activity Under OMB...-9/11 GI Bill Longitudinal Study Survey) in any correspondence For Further Information or a Copy of...

  1. Child Characteristics and Parental Educational Expectations: Evidence for Transmission with Transaction

    PubMed Central

    Briley, Daniel A.; Harden, K. Paige; Tucker-Drob, Elliot M.

    2014-01-01

    Parents’ expectations for their children’s ultimate educational attainment have been hypothesized to play an instrumental role in socializing academically-relevant child behaviors, beliefs, and abilities. In addition to social transmission of educationally relevant values from parents to children, parental expectations and child characteristics may transact bidirectionally. We explore this hypothesis using both longitudinal and genetically informative twin data from the Early Childhood Longitudinal Study –Birth and Kindergarten cohorts. Our behavior genetic results indicate that parental expectations partly reflect child genetic variation, even as early as 4 years of age. Two classes of child characteristics were hypothesized to contribute to these child-to-parent effects: behavioral tendencies (approaches toward learning and problem behaviors) and achievement (math and reading). Using behavior genetic models, we find within-twin-pair associations between these child characteristics and parental expectations. Using longitudinal cross-lagged models, we find that initial variation in child characteristics predicts future educational expectations above and beyond previous educational expectations. These results are consistent with transactional frameworks in which parent-to-child and child-to-parent effects co-occur. PMID:25285965

  2. Scaling relation of the anomalous Hall effect in (Ga,Mn)As

    NASA Astrophysics Data System (ADS)

    Glunk, M.; Daeubler, J.; Schoch, W.; Sauer, R.; Limmer, W.

    2009-09-01

    We present magnetotransport studies performed on an extended set of (Ga,Mn)As samples at 4.2 K with longitudinal conductivities σxx ranging from the low-conductivity to the high-conductivity regime. The anomalous Hall conductivity σxy(AH) is extracted from the measured longitudinal and Hall resistivities. A transition from σxy(AH)=20Ω-1cm-1 due to the Berry phase effect in the high-conductivity regime to a scaling relation σxy(AH)∝σxx1.6 for low-conductivity samples is observed. This scaling relation is consistent with a recently developed unified theory of the anomalous Hall effect in the framework of the Keldysh formalism. It turns out to be independent of crystallographic orientation, growth conditions, Mn concentration, and strain, and can therefore be considered universal for low-conductivity (Ga,Mn)As. The relation plays a crucial role when deriving values of the hole concentration from magnetotransport measurements in low-conductivity (Ga,Mn)As. In addition, the hole diffusion constants for the high-conductivity samples are determined from the measured longitudinal conductivities.

  3. Source Characteristics of the Northern Longitudinal Valley, Taiwan Derived from Broadband Strong-Motion Simulation

    NASA Astrophysics Data System (ADS)

    Wen, Yi-Ying

    2018-02-01

    The 2014 M L 5.9 Fanglin earthquake occurred at the northern end of the aftershock distribution of the 2013 M L 6.4 Ruisui event and caused strong ground shaking and some damage in the northern part of the Longitudinal Valley. We carried out the strong-motion simulation of the 2014 Fanglin event in the broadband frequency range (0.4-10 Hz) using the empirical Green's function method and then integrated the source models to investigate the source characteristics of the 2013 Ruisui and 2014 Fanglin events. The results show that the dimension of strong motion generation area of the 2013 Ruisui event is smaller, whereas that of the 2014 Fanglin event is comparable with the empirical estimation of inland crustal earthquakes, which indicates the different faulting behaviors. Furthermore, the localized high PGV patch might be caused by the radiation energy amplified by the local low-velocity structure in the northern Longitudinal Valley. Additional study issues are required for building up the knowledge of the potential seismic hazard related to moderate-large events for various seismogenic areas in Taiwan.

  4. Writing Abilities Longitudinally Predict Academic Outcomes of Adolescents with ADHD

    PubMed Central

    Molitor, Stephen J.; Langberg, Joshuah M.; Bourchtein, Elizaveta; Eddy, Laura D.; Dvorsky, Melissa R.; Evans, Steven W.

    2016-01-01

    Students with ADHD often experience a host of negative academic outcomes and deficits in reading and mathematics abilities contribute to these academic impairments. Students with ADHD may also have difficulties with written expression but there has been minimal research in this area and it is not clear whether written expression abilities uniquely contribute to the academic functioning of students with ADHD. The current study included a sample of 104 middle school students diagnosed with ADHD (grades 6–8). Participants were followed longitudinally to evaluate whether written expression abilities at baseline predicted student GPA and parent ratings of academic impairment 18 months later, after controlling for reading ability and additional relevant covariates. Written expression abilities longitudinally predicted both academic outcomes above and beyond ADHD and ODD symptoms, medication use, reading ability, and baseline values of GPA and parent-rated academic impairment. Follow-up analyses revealed that no single aspect of written expression was demonstrably more impactful on academic outcomes than the others, suggesting that writing as an entire process should be the focus of intervention. PMID:26783650

  5. Child characteristics and parental educational expectations: evidence for transmission with transaction.

    PubMed

    Briley, Daniel A; Harden, K Paige; Tucker-Drob, Elliot M

    2014-12-01

    Parents' expectations for their children's ultimate educational attainment have been hypothesized to play an instrumental role in socializing academically relevant child behaviors, beliefs, and abilities. In addition to social transmission of educationally relevant values from parents to children, parental expectations and child characteristics may transact bidirectionally. We explore this hypothesis using both longitudinal and genetically informative twin data from the Early Childhood Longitudinal Study-Birth and Kindergarten cohorts. Our behavior genetic results indicate that parental expectations partly reflect child genetic variation, even as early as 4 years of age. Two classes of child characteristics were hypothesized to contribute to these child-to-parent effects: behavioral tendencies (approaches toward learning and problem behaviors) and achievement (math and reading). Using behavior genetic models, we find within-twin-pair associations between these child characteristics and parental expectations. Using longitudinal cross-lagged models, we find that initial variation in child characteristics predicts future educational expectations above and beyond previous educational expectations. These results are consistent with transactional frameworks in which parent-to-child and child-to-parent effects co-occur. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  6. Automatic Marker-free Longitudinal Infrared Image Registration by Shape Context Based Matching and Competitive Winner-guided Optimal Corresponding

    PubMed Central

    Lee, Chia-Yen; Wang, Hao-Jen; Lai, Jhih-Hao; Chang, Yeun-Chung; Huang, Chiun-Sheng

    2017-01-01

    Long-term comparisons of infrared image can facilitate the assessment of breast cancer tissue growth and early tumor detection, in which longitudinal infrared image registration is a necessary step. However, it is hard to keep markers attached on a body surface for weeks, and rather difficult to detect anatomic fiducial markers and match them in the infrared image during registration process. The proposed study, automatic longitudinal infrared registration algorithm, develops an automatic vascular intersection detection method and establishes feature descriptors by shape context to achieve robust matching, as well as to obtain control points for the deformation model. In addition, competitive winner-guided mechanism is developed for optimal corresponding. The proposed algorithm is evaluated in two ways. Results show that the algorithm can quickly lead to accurate image registration and that the effectiveness is superior to manual registration with a mean error being 0.91 pixels. These findings demonstrate that the proposed registration algorithm is reasonably accurate and provide a novel method of extracting a greater amount of useful data from infrared images. PMID:28145474

  7. A longitudinal test of the demand-control model using specific job demands and specific job control.

    PubMed

    de Jonge, Jan; van Vegchel, Natasja; Shimazu, Akihito; Schaufeli, Wilmar; Dormann, Christian

    2010-06-01

    Supportive studies of the demand-control (DC) model were more likely to measure specific demands combined with a corresponding aspect of control. A longitudinal test of Karasek's (Adm Sci Q. 24:285-308, 1) job strain hypothesis including specific measures of job demands and job control, and both self-report and objectively recorded well-being. Job strain hypothesis was tested among 267 health care employees from a two-wave Dutch panel survey with a 2-year time lag. Significant demand/control interactions were found for mental and emotional demands, but not for physical demands. The association between job demands and job satisfaction was positive in case of high job control, whereas this association was negative in case of low job control. In addition, the relation between job demands and psychosomatic health symptoms/sickness absence was negative in case of high job control and positive in case of low control. Longitudinal support was found for the core assumption of the DC model with specific measures of job demands and job control as well as self-report and objectively recorded well-being.

  8. Tailored Panel Management: A Theory-Based Approach to Building and Maintaining Participant Commitment to a Longitudinal Study.

    PubMed

    Estrada, Mica; Woodcock, Anna; Schultz, P Wesley

    2014-02-01

    Many psychological processes unfold over time, necessitating longitudinal research designs. Longitudinal research poses a host of methodological challenges, foremost of which is participant attrition. Building on Dillman's work, we provide a review of how social influence and relationship research informs retention strategies in longitudinal studies. Objective: We introduce the tailored panel management (TPM) approach, which is designed to establish communal norms that increase commitment to a longitudinal study, and this commitment, in turn, increases response rates and buffers against attrition. Specifically, we discuss practices regarding compensation, communication, consistency, and credibility that increase longer term commitment to panel participation. Research design: Throughout the article, we describe how TPM is being used in a national longitudinal study of undergraduate minority science students. TheScienceStudy is a continuing panel, which has 12 waves of data collected across 6 academic years, with response rates ranging from 70% to 92%. Although more than 90% of participants have either left or graduated from their undergraduate degree program, this highly mobile group of people remains engaged in the study. TheScienceStudy has usable longitudinal data from 96% of the original panel. Conclusion: This article combines social psychological theory, current best practice, and a detailed case study to illustrate the TPM approach to longitudinal data collection. The approach provides guidance for other longitudinal researchers, and advocates for empirical research into longitudinal research methodologies. © The Author(s) 2014.

  9. Comparisons of Predictions of the XB-70-1 Longitudinal Stability and Control Derivatives with Flight Results for Six Flight Conditions

    NASA Technical Reports Server (NTRS)

    Wolowicz, C. H.; Yancey, R. B.

    1973-01-01

    Preliminary correlations of flight-determined and predicted stability and control characteristics of the XB-70-1 reported in NASA TN D-4578 were subject to uncertainties in several areas which necessitated a review of prediction techniques particularly for the longitudinal characteristics. Reevaluation and updating of the original predictions, including aeroelastic corrections, for six specific flight-test conditions resulted in improved correlations of static pitch stability with flight data. The original predictions for the pitch-damping derivative, on the other hand, showed better correlation with flight data than the updated predictions. It appears that additional study is required in the application of aeroelastic corrections to rigid model wind-tunnel data and the theoretical determination of dynamic derivatives for this class of aircraft.

  10. After High School: A First Look at the Postschool Experiences of Youth with Disabilities. A Report from the National Longitudinal Transition Study-2 (NLTS2)

    ERIC Educational Resources Information Center

    Wagner, Mary; Newman, Lynn; Cameto, Renee; Garza, Nicolle; Levine, Phyllis

    2005-01-01

    Background: The transition from high school can be difficult for any youth, but it can be particularly difficult for youth with disabilities, who may encounter additional challenges to negotiating the transition to young adulthood. Purpose: To describe the experiences of youth with disabilities in the postsecondary education, employment,…

  11. S/He's a Rebel: Toward a Sequential Stress Theory of Delinquency and Gendered Pathways to Disadvantage in Emerging Adulthood.

    ERIC Educational Resources Information Center

    Hagan, John; Foster, Holly

    2003-01-01

    Data from the National Longitudinal Study of Adolescent Health on 11,506 high school students were used to test a gendered and age-graded sequential stress theory in which delinquency can play an additive and intervening role in adolescents' movement from early anger through rebellious or aggressive forms of behavior to later depressive symptoms…

  12. Multi-Wave Prospective Examination of the Stress-Reactivity Extension of Response Styles Theory of Depression in High-Risk Children and Early Adolescents

    ERIC Educational Resources Information Center

    Abela, John R. Z.; Hankin, Benjamin L.; Sheshko, Dana M.; Fishman, Michael B.; Stolow, Darren

    2012-01-01

    The current study tested the stress-reactivity extension of response styles theory of depression (Nolen-Hoeksema "Journal of Abnormal Psychology" 100:569-582, 1991) in a sample of high-risk children and early adolescents from a vulnerability-stress perspective using a multi-wave longitudinal design. In addition, we examined whether obtained…

  13. Depression and family interaction among low-income, predominantly hispanic cancer patients: a longitudinal analysis.

    PubMed

    Oh, Hyunsung; Ell, Kathleen; Subica, Andrew

    2014-02-01

    Among cancer patients, family interaction has been associated with depression. According to the stress generation theory, depression among cancer patients triggers stressful interpersonal events that contribute to poor family interactions and additional depression. This conflict may occur with a spouse/partner or other family member, including extended family. This study evaluated the longitudinal association between depression and marital and family conflict among low-income, predominantly Hispanic cancer patients. Data were collected during a randomized controlled clinical trial of depression treatment among 472 low-income cancer patients with baseline depression scores of 10 or more on the Patient Health Questionnaire-9 and whose depression symptoms and negative family interactions were assessed at baseline and at 6, 12, 18, and 24 months. Considering that not all participants were in an intimate relationship, only 237 participants were included in the analysis of marital conflict. Mixed linear modeling with and without decomposition of between- and within-person variability was conducted to examine the longitudinal association between family interaction and depression. Overall, family conflict was significantly associated with changes in depression over time, and marital conflict was significantly associated with mean depression levels over 2 years. In addition, within-subject change in both marital and family conflict was significantly associated with within-patient deviation from average depression levels. Findings provide evidence of an association between depression and negative family interaction among depressed cancer patients. Cancer patients with clinically significant depressive symptoms may benefit from clinical assessment and psychotherapy relevant to family interaction.

  14. Estimated effects of in utero cocaine exposure on language development through early adolescence.

    PubMed

    Bandstra, Emmalee S; Morrow, Connie E; Accornero, Veronica H; Mansoor, Elana; Xue, Lihua; Anthony, James C

    2011-01-01

    The potential longitudinal effects of prenatal cocaine exposure (PCE) on language functioning were estimated from early childhood through early adolescence in a large, well-retained urban sample of 451 full-term children (242 cocaine-exposed, 209 non-cocaine-exposed) participating in the Miami Prenatal Cocaine Study (MPCS). The sample was enrolled prospectively at birth, with documentation of prenatal drug exposure status through maternal interview, and toxicology assays of maternal and infant urine, and infant meconium. Age-appropriate versions of the Clinical Evaluation of Language Fundamentals (CELF) were used to measure total, expressive, and receptive language at ages 3, 5, and 12years. Longitudinal latent growth curve (LLGC) modeling of the data revealed an association between PCE (measured dichotomously as yes/no) and lower functioning in expressive and total language scores, after considering other sources of variation including child's age at testing, sex, prenatal exposure to alcohol, marijuana, and tobacco, and additional medical and social-demographic covariates. Analyses of level of PCE showed a gradient, i.e. dose-dependent, relationship between PCE level and expressive, receptive, and total language scores in the models controlling for age, child's sex, and other prenatal drug exposures. With additional covariate control these findings were most stable for the total language score. The evidence supports an inference about an enduring stable cocaine-specific effect on children's language abilities, with no effect on language growth over time in the longitudinal trajectory of language development. Copyright © 2010 Elsevier Inc. All rights reserved.

  15. SCI Longitudinal Aging Study: 40 Years of Research.

    PubMed

    Krause, James S; Clark, Jillian M R; Saunders, Lee L

    2015-01-01

    The Spinal Cord Injury (SCI) Longitudinal Aging Study was initiated in 1973 and has conducted 8 assessments over the past 40 years. It was designed to help rehabilitation professionals understand the life situation of people with SCI, but it has developed into the most long-standing study of aging and SCI and has resulted in over 50 publications. Our purpose was to provide a detailed history of the study, response patterns, utilization of measures, and a summary of key findings reported in the literature. Five participant samples have been incorporated over the 40 years, with enrollment in 1973, 1984, 1993 (2 samples), and 2003. A total of 2,208 participants have completed 6,001 assessments, with a particularly large number of assessments among those who are more than 40 years post injury (n = 349). The overall results have indicated changing patterns of outcomes over time as persons with SCI age, with some notable declines in participation and health. There has been a survivor effect whereby persons who are more active, well-adjusted, and healthier live longer. This study has several important features that are required for longitudinal research including (a) consistency of follow-up, (b) consistency of measures over time, (c) addition of new participant samples to counteract attrition, and (d) inclusion of a large number of individuals who have reached aging milestones unparalleled in the literature. Data from this study can inform the literature on the natural course of aging with SCI.

  16. Socio-economic differences in predictors of frequent dairy food consumption among Australian adolescents: a longitudinal study.

    PubMed

    Stephens, Lena D; McNaughton, Sarah A; Crawford, David; Ball, Kylie

    2015-12-01

    Sufficient dairy food consumption during adolescence is necessary for preventing disease. While socio-economically disadvantaged adolescents tend to consume few dairy foods, some eat quantities more in line with dietary recommendations despite socio-economic challenges. Socio-economic variations in factors supportive of adolescents' frequent dairy consumption remain unexplored. The present study aimed to identify cross-sectional and longitudinal associations between intrapersonal, social and environmental factors and adolescents' frequent dairy consumption at baseline and two years later across socio-economic strata, and to examine whether socio-economic position moderated observed effects. Online surveys completed at baseline (2004-2005) and follow-up (2006-2007) included a thirty-eight-item FFQ and questions based on social ecological models examining intrapersonal, social and environmental dietary influences. Thirty-seven secondary schools in Victoria, Australia. Australian adolescents (n 1201) aged 12-15 years, drawn from a sub-sample of 3264 adolescents (response rate=33%). While frequent breakfast consumption was cross-sectionally associated with frequent dairy consumption among all adolescents, additional associated factors differed by socio-economic position. Baseline dairy consumption longitudinally predicted consumption at follow-up. No further factors predicted frequent consumption among disadvantaged adolescents, while four additional factors were predictive among advantaged adolescents. Socio-economic position moderated two predictors; infrequently eating dinner alone and never purchasing from school vending machines predicted frequent consumption among advantaged adolescents. Nutrition promotion initiatives aimed at improving adolescents' dairy consumption should employ multifactorial approaches informed by social ecological models and address socio-economic differences in influences on eating behaviours; e.g., selected intrapersonal factors among all adolescents and social factors (e.g., mealtime rules) among advantaged adolescents.

  17. Is Augmented LISS Plating Biomechanically Advantageous Over Conventional LISS Plating In Unstable Osteoporotic Distal Femoral Fractures?

    PubMed

    Todorov, Dimitar; Zderic, Ivan; Richards, R Geoff; Lenz, Mark; Knobe, Matthias; Enchev, Dian; Baltov, Asen; Gueorguiev, Boyko; Stoffel, Karl

    2018-05-10

    Treatment of complex osteoporotic distal femur fractures with the Less Invasive Stabilization System (LISS) has been associated with high complication rates. The aim of this study was to investigate the biomechanical competence of two different techniques of augmented versus conventional LISS plating. Unstable distal femoral fracture AO/OTA 33-A3 was created via osteotomies in artificial femora simulating osteoporotic bone. Three study groups, consisting of 10 specimens each, were created for instrumentation with either LISS plate, LISS plate with additional polylactide intramedullary graft, or LISS plate plus medial locking plate (double plating). All specimens were non-destructively tested under axial (20-150N) and torsional (0-4Nm) quasi-static loading. Each construct was tested with two different working length (WL) configurations (long and short) of the LISS plate. Relative movements between the most medial superior and inferior osteotomy aspects were investigated via three-dimensional motion tracking analysis. Double plating revealed significantly smaller longitudinal and shear displacement than the other two techniques (P≤0.001). In addition, LISS plus graft fixation was with significantly less longitudinal displacement in comparison to conventional LISS plating (P < 0.001). Long WL resulted in significantly higher longitudinal and shear displacement compared to short WL for LISS and LISS plus graft (P≤0.032), but not for double plating (P > 0.999). In conclusion, intramedullary grafting resulted in significantly increased fracture stability under axial loading in comparison to conventional LISS plating. Although it was not efficient enough to provide comparable stability to double plating, intramedullary grafting may be considered as a useful biological alternative to the latter in a surgeon's armamentarium. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  18. Intergenerational transmission of family meal patterns from adolescence to parenthood: longitudinal associations with parents' dietary intake, weight-related behaviours and psychosocial well-being.

    PubMed

    Berge, Jerica M; Miller, Jonathan; Watts, Allison; Larson, Nicole; Loth, Katie A; Neumark-Sztainer, Dianne

    2018-02-01

    The present study examined longitudinal associations between four family meal patterns (i.e. never had regular family meals, started having regular family meals, stopped having regular family meals, maintained having regular family meals) and young adult parents' dietary intake, weight-related behaviours and psychosocial well-being. In addition, family meal patterns of parents were compared with those of non-parents. Analysis of data from the longitudinal Project EAT (Eating and Activity in Adolescents and Young Adults) study. Linear and logistic regressions were used to examine the associations between family meal patterns and parents' dietary intake, weight-related behaviours and psychosocial well-being. School and in-home settings. At baseline (1998; EAT-I), adolescents (n 4746) from socio-economically and racially/ethnically diverse households completed a survey and anthropometric measurements at school. At follow-up (2015; EAT-IV), participants who were parents (n 726) and who were non-parents with significant others (n 618) completed an online survey. Young adult parents who reported having regular family meals as an adolescent and as a parent ('maintainers'), or who started having regular family meals with their own families ('starters'), reported more healthful dietary, weight-related and psychosocial outcomes compared with young adults who never reported having regular family meals ('nevers'; P<0·05). In addition, parents were more likely to be family meal starters than non-parents. Results suggest that mental and physical health benefits of having regular family meals may be realized as a parent whether the routine of regular family meals is carried forward from adolescence into parenthood, or if the routine is started in parenthood.

  19. Cultural events - does attendance improve health? Evidence from a Polish longitudinal study.

    PubMed

    Węziak-Białowolska, Dorota; Białowolski, Piotr

    2016-08-05

    Although there is strong advocacy for uptake of both the arts and creative activities as determinants of individual health conditions, studies evaluating causal influence of attendance at cultural events on population health using individual population data on health are scarce. If available, results are often only of an associative nature. In this light, this study investigated causative impact of attendance at cultural events on self-reported and physical health in the Polish population. Four recent waves (2009, 2011, 2013 and 2015) of the biennial longitudinal Polish household panel study, Social Diagnosis, were analysed. The data, representative for the Polish population aged over 16, with respect to age, gender, classes of place of residence and NUTS 2 regions, were collected from self-report questionnaires. Causative influence of cultural attendance on population health was established using longitudinal population representative data. To account for unobserved heterogeneity of individuals and to mitigate issues caused by omitted variables, a panel data model with a fixed effects estimator was applied. The endogeneity problem (those who enjoy good health are more likely to participate in cultural activities more frequently) was circumvented by application of instrumental variables. Results confirmed positive association between cultural attendance and self-reported health. However, in contrast to the often suggested positive causative relationship, such a link was not confirmed by the study. Additionally, no evidence was found to corroborate a positive impact from cultural attendance on physical health. Both findings were substantiated by augmentation in the longitudinal perspective and causal link. We showed the relation between attendance at cultural events and self-reported health could only be confirmed as associational. Therefore, this study provided little justification to encourage use of passive cultural participation as a measure of health promotion (improvement). Our study did not confirm any identifiable benefit to physical health from passive participation in culture. Future research should investigate the causative influence of active participation in creative activities on health outcomes as, in contrast to passive attendance, it may be influential.

  20. Dense home-based recordings reveal typical and atypical development of tense/aspect in a child with delayed language development.

    PubMed

    Chin, Iris; Goodwin, Matthew S; Vosoughi, Soroush; Roy, Deb; Naigles, Letitia R

    2018-01-01

    Studies investigating the development of tense/aspect in children with developmental disorders have focused on production frequency and/or relied on short spontaneous speech samples. How children with developmental disorders use future forms/constructions is also unknown. The current study expands this literature by examining frequency, consistency, and productivity of past, present, and future usage, using the Speechome Recorder, which enables collection of dense, longitudinal audio-video recordings of children's speech. Samples were collected longitudinally in a child who was previously diagnosed with autism spectrum disorder, but at the time of the study exhibited only language delay [Audrey], and a typically developing child [Cleo]. While Audrey was comparable to Cleo in frequency and productivity of tense/aspect use, she was atypical in her consistency and production of an unattested future form. Examining additional measures of densely collected speech samples may reveal subtle atypicalities that are missed when relying on only few typical measures of acquisition.

  1. A Neonatal Resuscitation Curriculum in Malawi, Africa: Did It Change In-Hospital Mortality?

    PubMed Central

    Hole, Michael K.; Olmsted, Keely; Kiromera, Athanase; Chamberlain, Lisa

    2012-01-01

    Objective. The WHO estimates that 99% of the 3.8 million neonatal deaths occur in developing countries. Neonatal resuscitation training was implemented in Namitete, Malawi. The study's objective was to evaluate the training's impact on hospital staff and neonatal mortality rates. Study Design. Pre-/postcurricular surveys of trainee attitude, knowledge, and skills were analyzed. An observational, longitudinal study of secondary data assessed neonatal mortality. Result. All trainees' (n = 18) outcomes improved, (P = 0.02). Neonatal mortality did not change. There were 3449 births preintervention, 3515 postintervention. Neonatal mortality was 20.9 deaths per 1000 live births preintervention and 21.9/1000 postintervention, (P = 0.86). Conclusion. Short-term pre-/postintervention evaluations frequently reveal positive results, as ours did. Short-term pre- and postintervention evaluations should be interpreted cautiously. Whenever possible, clinical outcomes such as in-hospital mortality should be additionally assessed. More rigorous evaluation strategies should be applied to training programs requiring longitudinal relationships with international community partners. PMID:22164184

  2. Summary of longitudinal stability and control parameters as determined from space shuttle Columbia flight test data

    NASA Technical Reports Server (NTRS)

    Suit, W. T.

    1986-01-01

    Extensive wind tunnel tests were conducted to establish the preflight aerodynamics of the Shuttle vehicle. This paper presents the longitudinal, short-period aerodynamics of the space shuttle Columbia as determined from flight test data. These flight-determined results are compared with the preflight predictions, and areas of agreement or disagreement are noted. In addition to the short-period aerodynamics, the pitch RCS effectiveness was determined.

  3. Longitudinal dynamics of an intense electron beam

    NASA Astrophysics Data System (ADS)

    Harris, John Richardson

    2005-11-01

    The dynamics of charged particle beams are governed by the particles' thermal velocities, external focusing forces, and Coulomb forces. Beams in which Coulomb forces play the dominant role are known as space charge dominated, or intense. Intense beams are of great interest for heavy ion fusion, spallation neutron sources, free-electron lasers, and other applications. In addition, all beams of interest are dominated by space charge forces when they are first created, so an understanding of space charge effects is critical to explain the later evolution of any beam. Historically, more attention has been paid to the transverse dynamics of beams. However, many interesting and important effects in beams occur along their length. These longitudinal effects can be limiting factors in many systems. For example, modulation or structure applied to the beam at low energy will evolve under space charge forces. Depending on the intended use of the beam and the nature of the modulation, this may result in improved or degraded performance. To study longitudinal dynamics in intense beams, experiments were conducted using the University of Maryland Electron Ring, a 10 keV, 100 mA electron transport system. These experiments concentrated on space charge driven changes in beam length in parabolic and rectangular beams, beam density and velocity modulation, and space charge wave propagation. Coupling between the transverse and longitudinal dynamics was also investigated. These experiments involved operating the UMER gun in space charge limited, temperature limited, triode amplification, photon limited, and hybrid modes. Results of these experiments are presented here, along with a theoretical framework for understanding the longitudinal dynamics of intense beams.

  4. Longitudinal relationships among posturography and gait measures in multiple sclerosis.

    PubMed

    Fritz, Nora E; Newsome, Scott D; Eloyan, Ani; Marasigan, Rhul Evans R; Calabresi, Peter A; Zackowski, Kathleen M

    2015-05-19

    Gait and balance dysfunction frequently occurs early in the multiple sclerosis (MS) disease course. Hence, we sought to determine the longitudinal relationships among quantitative measures of gait and balance in individuals with MS. Fifty-seven ambulatory individuals with MS (28 relapsing-remitting, 29 progressive) were evaluated using posturography, quantitative sensorimotor and gait measures, and overall MS disability with the Expanded Disability Status Scale at each session. Our cohort's age was 45.8 ± 10.4 years (mean ± SD), follow-up time 32.8 ± 15.4 months, median Expanded Disability Status Scale score 3.5, and 56% were women. Poorer performance on balance measures was related to slower walking velocity. Two posturography measures, the anterior-posterior sway and sway during static eyes open, feet apart conditions, were significant contributors to walk velocity over time (approximate R(2) = 0.95), such that poorer performance on the posturography measures was related to slower walking velocity. Similarly, the anterior-posterior sway and sway during static eyes closed, feet together conditions were also significant contributors to the Timed 25-Foot Walk performance over time (approximate R(2) = 0.83). This longitudinal cohort study establishes a strong relationship between clinical gait measures and posturography. The data show that increases in static posturography and reductions in dynamic posturography are associated with a decline in walk velocity and Timed 25-Foot Walk performance over time. Furthermore, longitudinal balance measures predict future walking performance. Quantitative walking and balance measures are important additions to clinical testing to explore longitudinal change and understand fall risk in this progressive disease population. © 2015 American Academy of Neurology.

  5. Regulatory gene expression patterns reveal transverse and longitudinal subdivisions of the embryonic zebrafish forebrain.

    PubMed

    Hauptmann, G; Gerster, T

    2000-03-01

    To shed light on the organization of the rostral embryonic brain of a lower vertebrate, we have directly compared the expression patterns of dlx, fgf, hh, hlx, otx, pax, POU, winged helix and wnt gene family members in the fore- and midbrain of the zebrafish. We show that the analyzed genes are expressed in distinct transverse and longitudinal domains and share expression boundaries at stereotypic positions within the fore- and midbrain. Some of these shared expression boundaries coincide with morphological landmarks like the pathways of primary axon tracts. We identified a series of eight transverse diencephalic domains suggestive of neuromeric subdivisions within the rostral brain. In addition, we identified four molecularly distinct longitudinal subdivisions and provide evidence for a strong bending of the longitudinal rostral brain axis at the cephalic flexure. Our data suggest a strong conservation of early forebrain organization between lower and higher vertebrates.

  6. Ultrasonic attenuation in pearlitic steel.

    PubMed

    Du, Hualong; Turner, Joseph A

    2014-03-01

    Expressions for the attenuation coefficients of longitudinal and transverse ultrasonic waves are developed for steel with pearlitic microstructure. This type of lamellar duplex microstructure influences attenuation because of the lamellar spacing. In addition, longitudinal attenuation measurements were conducted using an unfocused transducer with 10 MHz central frequency on the cross section of a quenched railroad wheel sample. The dependence of longitudinal attenuation on the pearlite microstructure is observed from the changes of longitudinal attenuation from the quenched tread surface to deeper locations. The results show that the attenuation value is lowest and relatively constant within the quench depth, then increases linearly. The experimental results demonstrate a reasonable agreement with results from the theoretical model. Ultrasonic attenuation provides an important non-destructive method to evaluate duplex microstructure within grains which can be implemented for quality control in conjunction with other manufacturing processes. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Stabilized and tunable single-longitudinal-mode erbium fiber laser employing ytterbium-doped fiber based interference filter

    NASA Astrophysics Data System (ADS)

    Yeh, Chien-Hung; Tsai, Ning; Zhuang, Yuan-Hong; Chow, Chi-Wai; Chen, Jing-Heng

    2017-02-01

    In this demonstration, to achieve stabilized and wavelength-selectable single-longitudinal-mode (SLM) erbium-doped fiber (EDF) laser, a short length of ytterbium-doped fiber (YDF) is utilized to serve as a spatial multi-mode interference (MMI) inside a fiber cavity for suppressing multi-longitudinal-mode (MLM) significantly. In the measurement, the output powers and optical signal to noise ratios (OSNRs) of proposed EDF ring laser are measured between -9.85 and -5.71 dBm; and 38.03 and 47.95 dB, respectively, in the tuning range of 1530.0-1560.0 nm. In addition, the output SLM and stability performance are also analyzed and discussed experimentally.

  8. Longitudinal phase-space coating of beam in a storage ring

    NASA Astrophysics Data System (ADS)

    Bhat, C. M.

    2014-06-01

    In this Letter, I report on a novel scheme for beam stacking without any beam emittance dilution using a barrier rf system in synchrotrons. The general principle of the scheme called longitudinal phase-space coating, validation of the concept via multi-particle beam dynamics simulations applied to the Fermilab Recycler, and its experimental demonstration are presented. In addition, it has been shown and illustrated that the rf gymnastics involved in this scheme can be used in measuring the incoherent synchrotron tune spectrum of the beam in barrier buckets and in producing a clean hollow beam in longitudinal phase space. The method of beam stacking in synchrotrons presented here is the first of its kind.

  9. Longitudinal Association between Periodontitis and Development of Diabetes Running title: Periodontitis and Diabetes Development.

    PubMed

    Joshipura, Kaumudi J; Muñoz-Torres, Francisco J; Dye, Bruce A; Leroux, Brian G; Ramírez-Vick, Margarita; Pérez, Cynthia M

    2018-04-18

    Clinical trials have shown very modest short-term improvements in glycemic control among participants with diabetes after periodontitis treatment. Few longitudinal studies suggest that periodontitis may be related to prediabetes/diabetes risk. We evaluated 1,206 diabetes free participants in the San Juan Overweight Adults Longitudinal Study (SOALS) and 941 with complete 3-year follow-up data were included. The National Health and Nutrition Examination Survey (NHANES) methods were used to assess periodontitis. Diabetes and prediabetes were classified using American Diabetes Association cutoffs for fasting and 2-hour post-load glucose and HbA1c. We used Poisson regression adjusting for baseline age, gender, smoking, education, family history of diabetes, physical activity, waist circumference, and alcohol intake. Over the 3-year follow-up, 69 (7.3%) of the 941 individuals developed type 2 diabetes, and 142 (34.9%) of the 407 with normal glycemia at baseline developed prediabetes. In multivariable models, greater mean pocket depth and mean attachment loss at baseline were associated with lower risk of developing prediabetes/diabetes over the follow-up (IRR=0.81; 95% CI: 0.67-0.99, and IRR=0.86; 95% CI: 0.74-0.99, respectively). Increase in periodontal attachment loss from baseline to follow-up was associated with higher prediabetes/diabetes risk (multivariate IRR=1.25; 95% CI: 1.09-1.42), and increase in pocket depth was associated with >20% fasting glucose increase (multivariate IRR=1.43; 95% CI: 1.14-1.79). The inverse associations persisted after additionally adjusting for baseline income, sugar-sweetened beverages, number of teeth, oral hygiene, glycemia, or previous periodontal therapy. There is no association between periodontitis and risk of prediabetes/diabetes in this longitudinal study. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. Job Strain and Tobacco Smoking: An Individual-Participant Data Meta-Analysis of 166 130 Adults in 15 European Studies

    PubMed Central

    Heikkilä, Katriina; Nyberg, Solja T.; Fransson, Eleonor I.; Alfredsson, Lars; De Bacquer, Dirk; Bjorner, Jakob B.; Bonenfant, Sébastien; Borritz, Marianne; Burr, Hermann; Clays, Els; Casini, Annalisa; Dragano, Nico; Erbel, Raimund; Geuskens, Goedele A.; Goldberg, Marcel; Hooftman, Wendela E.; Houtman, Irene L.; Joensuu, Matti; Jöckel, Karl-Heinz; Kittel, France; Knutsson, Anders; Koskenvuo, Markku; Koskinen, Aki; Kouvonen, Anne; Leineweber, Constanze; Lunau, Thorsten; Madsen, Ida E. H.; Hanson, Linda L. Magnusson; Marmot, Michael G.; Nielsen, Martin L.; Nordin, Maria; Pentti, Jaana; Salo, Paula; Rugulies, Reiner; Steptoe, Andrew; Siegrist, Johannes; Suominen, Sakari; Vahtera, Jussi; Virtanen, Marianna; Väänänen, Ari; Westerholm, Peter; Westerlund, Hugo; Zins, Marie; Theorell, Töres; Hamer, Mark; Ferrie, Jane E.; Singh-Manoux, Archana; Batty, G. David; Kivimäki, Mika

    2012-01-01

    Background Tobacco smoking is a major contributor to the public health burden and healthcare costs worldwide, but the determinants of smoking behaviours are poorly understood. We conducted a large individual-participant meta-analysis to examine the extent to which work-related stress, operationalised as job strain, is associated with tobacco smoking in working adults. Methodology and Principal Findings We analysed cross-sectional data from 15 European studies comprising 166 130 participants. Longitudinal data from six studies were used. Job strain and smoking were self-reported. Smoking was harmonised into three categories never, ex- and current. We modelled the cross-sectional associations using logistic regression and the results pooled in random effects meta-analyses. Mixed effects logistic regression was used to examine longitudinal associations. Of the 166 130 participants, 17% reported job strain, 42% were never smokers, 33% ex-smokers and 25% current smokers. In the analyses of the cross-sectional data, current smokers had higher odds of job strain than never-smokers (age, sex and socioeconomic position-adjusted odds ratio: 1.11, 95% confidence interval: 1.03, 1.18). Current smokers with job strain smoked, on average, three cigarettes per week more than current smokers without job strain. In the analyses of longitudinal data (1 to 9 years of follow-up), there was no clear evidence for longitudinal associations between job strain and taking up or quitting smoking. Conclusions Our findings show that smokers are slightly more likely than non-smokers to report work-related stress. In addition, smokers who reported work stress smoked, on average, slightly more cigarettes than stress-free smokers. PMID:22792154

  11. The Association of Health and Employment in Mature Women: A Longitudinal Study

    PubMed Central

    Byles, Julie

    2012-01-01

    Abstract Background Despite a reduction in income inequalities between men and women, there is still a large gap between income and retirement savings of Australian men and women. This is especially true for women who have health or disability problems. Mature age women are closest to retirement and, therefore, have less chance than younger women to build up enough retirement savings and may need to continue working to fund their older age. Continued workforce participation may be particularly difficult for women who are less healthy. Understanding which health problems lead to a decrease in workforce participation among mature age women is crucial. Therefore, this longitudinal study sought to identify which health problems are associated with employment among midage women over time. Methods Data were analyzed from the midage cohort of the Australian Longitudinal Study on Women's Health (ALSWH), which involved 14,200 midage women (aged 45–50 years in 1996). The women have been surveyed four additional times, in 1998, 2001, 2004, and 2007. Generalized estimating equations (GEE) were used to conduct nested multivariate longitudinal analyses. Results The percentages of women who were employed in the years 2001, 2004, and 2007 were 77%, 72%, and 68%, respectively. Results were adjusted for sociodemographic variables. Being employed decreased as physical and mental health deteriorated and with self-reported conditions: diabetes, high blood pressure, depression, anxiety, and other psychiatric conditions. Back pain, arthritis, cancer, obesity, and being a current smoker are associated with employment but not when quality of life is added to the model. Conclusions There were significant associations between health and employment. Understanding these relationships could inform policies and guidelines for preventing declines in employment in mature age women. PMID:22060315

  12. Parental eating behaviours, home food environment and adolescent intakes of fruits, vegetables and dairy foods: longitudinal findings from Project EAT.

    PubMed

    Arcan, Chrisa; Neumark-Sztainer, Dianne; Hannan, Peter; van den Berg, Patricia; Story, Mary; Larson, Nicole

    2007-11-01

    To examine longitudinal associations of parental report of household food availability and parent intakes of fruits, vegetables and dairy foods with adolescent intakes of the same foods. This study expands upon the limited research of longitudinal studies examining the role of parents and household food availability in adolescent dietary intakes. Longitudinal study. Project EAT-II followed an ethnically and socio-economically diverse sample of adolescents from 1999 (time 1) to 2004 (time 2). In addition to the Project EAT survey, adolescents completed the Youth Adolescent Food-Frequency Questionnaire in both time periods, and parents of adolescents completed a telephone survey at time 1. General linear modelling was used to examine the relationship between parent intake and home availability and adolescent intake, adjusting for time 1 adolescent intakes. Associations were examined separately for the high school and young adult cohorts and separately for males and females in combined cohorts. The sample included 509 pairs of parents/guardians and adolescents. Vegetables served at dinner significantly predicted adolescent intakes of vegetables for males (P = 0.037), females (P = 0.009), high school (P = 0.033) and young adults (P = 0.05) at 5-year follow-up. Among young adults, serving milk at dinner predicted dairy intake (P = 0.002). Time 1 parental intakes significantly predicted intakes of young adults for fruit (P = 0.044), vegetables (P = 0.041) and dairy foods (P = 0.008). Parental intake predicted intake of dairy for females (P = 0.02). The findings suggest the importance of providing parents of adolescents with knowledge and skills to enhance the home food environment and improve their own eating behaviours.

  13. Psychiatric Disorders and General Functioning in Low Birth Weight Adults: A Longitudinal Study.

    PubMed

    Lærum, Astrid M W; Reitan, Solveig Klæbo; Evensen, Kari Anne I; Lydersen, Stian; Brubakk, Ann-Mari; Skranes, Jon; Indredavik, Marit S

    2017-02-01

    To examine psychiatric morbidity and overall functioning in adults born with low birth weight compared with normal birth weight controls at age 26 years and to study longitudinal trajectories of psychiatric morbidity from early adolescence to adulthood. Prospective cohort study wherein 44 preterm very low birth weight (≤1500 g), 64 term small for gestational age (SGA; <10th percentile), and 81 control adults were examined using the MINI-International Neuropsychiatric Interview: M.I.N.I. Plus, Norwegian version, the Global Assessment of Functioning, and questions on daily occupation and level of education. Prevalence of psychiatric disorders from previous follow-ups at age 14 and 19 years were included for longitudinal analysis. From adolescence to adulthood, the term SGA group had a marked increase in the estimated probability of psychiatric disorders from 9% (95% confidence interval, 4-19) to 39% (95% confidence interval, 28-51). At 26 years, psychiatric diagnoses were significantly more prevalent in the preterm very low birth weight group (n = 16, 36%; P = .003) and the term SGA group (n = 24, 38%; P = .019) compared with the control group (n = 11, 14%). Both low birth weight groups had lower educational level and functioning scores than controls and a higher frequency of unemployment and disability benefit. Low birth weight was a substantial risk factor for adult psychiatric morbidity and lowered overall functioning. The results underscore the need for long-term follow-up of low birth weight survivors through adolescence and adulthood, focusing on mental health. The longitudinal increase in psychiatric morbidity in the term SGA group calls for additional investigation. Copyright © 2017 by the American Academy of Pediatrics.

  14. Food insufficiency, housing and health-related quality of life: results from the Positive Spaces, Healthy Places study.

    PubMed

    Choi, Stephanie K Y; Fielden, Sarah; Globerman, Jason; Koornstra, J J Jay; Hambly, Keith; Walker, Glen; Sobota, Michael; O'Brien-Teengs, Doe; Watson, James; Bekele, Tsegaye; Greene, Saara; Tucker, Ruthann; Hwang, Stephen W; Rourke, Sean B; Healthy Places Team, The Positive Spaces

    2015-01-01

    Studies of people living with HIV who are homeless or unstably housed show a high prevalence of food insufficiency (>50%) and associated poor health outcomes; however, most evidence is in the form of cross-sectional studies. To better understand this issue, we conducted a longitudinal study to examine the impact of food insufficiency and housing instability on overall physical and mental health-related quality of life (HRQoL) among people living with HIV in Ontario. Six hundred and two adults living with HIV were enrolled in the Positive Spaces, Healthy Places study and followed from 2006 to 2009. Interviewer-administered questionnaires were used, and generalized linear mixed-effects models constructed to examine longitudinal associations between food insufficiency, housing instability and physical and mental HRQoL. At baseline, 57% of participants were classified as food insufficient. After adjusting for potential confounders, longitudinal analyses revealed a significant, negative association between food insufficiency and physical and mental HRQoL outcomes, respectively [effect size (ES) with 95% confidence interval (CI): (ES = -2.1, CI = -3.9,-0.3); (ES = -3.5, CI = -6.1,-1.5)]. Furthermore, difficulties meeting housing costs were shown to have additional negative impacts on mental HRQoL. Food insufficiency is highly prevalent among people living with HIV in Ontario, particularly for those with unstable housing. This vulnerable group of individuals is in urgent need of changes to current housing programmes, services and policies, as well as careful consideration of their unmet nutritional needs.

  15. Parenting, relational aggression, and borderline personality features: associations over time in a Russian longitudinal sample.

    PubMed

    Nelson, David A; Coyne, Sarah M; Swanson, Savannah M; Hart, Craig H; Olsen, Joseph A

    2014-08-01

    Crick, Murray-Close, and Woods (2005) encouraged the study of relational aggression as a developmental precursor to borderline personality features in children and adolescents. A longitudinal study is needed to more fully explore this association, to contrast potential associations with physical aggression, and to assess generalizability across various cultural contexts. In addition, parenting is of particular interest in the prediction of aggression or borderline personality disorder. Early aggression and parenting experiences may differ in their long-term prediction of aggression or borderline features, which may have important implications for early intervention. The currrent study incorporated a longitudinal sample of preschool children (84 boys, 84 girls) living in intact, two-parent biological households in Voronezh, Russia. Teachers provided ratings of children's relational and physical aggression in preschool. Mothers and fathers also self-reported their engagement in authoritative, authoritarian, permissive, and psychological controlling forms of parenting with their preschooler. A decade later, 70.8% of the original child participants consented to a follow-up study in which they completed self-reports of relational and physical aggression and borderline personality features. The multivariate results of this study showed that preschool relational aggression in girls predicted adolescent relational aggression. Preschool aversive parenting (i.e., authoritarian, permissive, and psychologically controlling forms) significantly predicted aggression and borderline features in adolescent females. For adolescent males, preschool authoritative parenting served as a protective factor against aggression and borderline features, whereas authoritarian parenting was a risk factor for later aggression.

  16. A Longitudinal Study of Fathers' and Young Children's Depressive Symptoms.

    PubMed

    Tichovolsky, Marianne H; Griffith, Shayl F; Rolon-Arroyo, Benjamin; Arnold, David H; Harvey, Elizabeth A

    2016-09-21

    Considerable research has examined the effects of maternal depression on children, but few studies have focused on the relation between paternal and child depressive symptoms, particularly during early childhood. Even fewer studies have been longitudinal, leaving open questions about how paternal and child depression covary over time. The present study sought to address this gap by examining the relation between fathers' and children's depressive symptoms over a 3-year period. Participants were 153 preschool children with behavior problems and their parents. Three longitudinal analytic approaches were used to examine how father and child depression change together and predict one another over time. Additional analyses examined whether externalizing problems or maternal depression might account for the associations between fathers' and children's depressive symptoms. Changes in paternal depression significantly predicted changes in father-reported and mother-reported child depressive symptoms. These effects were evident both in year-to-year fluctuations and in linear trajectories across the 3-year period. Cross-lagged analyses suggested that these relations may have been driven by father-effects; paternal depression at one time point predicted child depression at the next time point, but child depression did not significantly predict later paternal depression. We found little evidence that externalizing problems or maternal depression accounted for the relations between fathers' and children's depressive symptoms. Results provide convergent evidence that fathers' depression may play an important role in the development of depressive symptoms in young children and underscore the importance of including fathers in studies of depression in families.

  17. Vascular risk factors and neuropsychiatric symptoms in Alzheimer's disease: the Cache County Study.

    PubMed

    Steinberg, Martin; Hess, Kyle; Corcoran, Chris; Mielke, Michelle M; Norton, Maria; Breitner, John; Green, Robert; Leoutsakos, Jeannie; Welsh-Bohmer, Kathleen; Lyketsos, Constantine; Tschanz, Joann

    2014-02-01

    Knowledge of potentially modifiable risk factors for neuropsychiatric symptoms (NPS) in Alzheimer's disease (AD) is important. This study longitudinally explores modifiable vascular risk factors for NPS in AD. Participants enrolled in the Cache County Study on Memory in Aging with no dementia at baseline were subsequently assessed over three additional waves, and those with incident (new onset) dementia were invited to join the Dementia Progression Study for longitudinal follow-up. A total of 327 participants with incident AD were identified and assessed for the following vascular factors: atrial fibrillation, hypertension, diabetes mellitus, angina, coronary artery bypass surgery, myocardial infarction, cerebrovascular accident, and use of antihypertensive or diabetes medicines. A vascular index (VI) was also calculated. NPS were assessed over time using the Neuropsychiatric Inventory (NPI). Affective and Psychotic symptom clusters were assessed separately. The association between vascular factors and change in NPI total score was analyzed using linear mixed model and in symptom clusters using a random effects model. No individual vascular risk factors or the VI significantly predicted change in any individual NPS. The use of antihypertensive medications more than four times per week was associated with higher total NPI and Affective cluster scores. Use of antihypertensive medication was associated with higher total NPI and Affective cluster scores. The results of this study do not otherwise support vascular risk factors as modifiers of longitudinal change in NPS in AD. Copyright © 2013 John Wiley & Sons, Ltd.

  18. Six-month longitudinal associations between cognitive functioning and distress among the community-based elderly in Hong Kong: A cross-lagged panel analysis.

    PubMed

    Leung, Chantel Joanne; Cheng, Lewis; Yu, Junhong; Yiend, Jenny; Lee, Tatia M C

    2018-07-01

    Although previous studies have extensively documented the cross-sectional relationship between cognitive impairment and psychological distress, findings relating to their longitudinal associations remains mixed. The present study examines the longitudinal associations and mutual influence between cognitive functioning and psychological distress across six months among community-dwelling elderly in Hong Kong. A total of 162 older adults (40 males; M age  = 69.8 years, SD = 6.4) were administered objective and subjective measures of cognitive functioning, as well as self-reported ratings of distress, at two time points six months apart. Using structural equation modeling, we tested the cross-lagged relationships between cognitive functioning and distress. Our cross-lagged model indicated that cognitive functioning at baseline significantly predicted subsequent psychological distress. However, distress was not significantly associated with subsequent cognitive functioning. Additionally, the objective and subjective measures of cognitive functioning were not significantly correlated. These findings suggested that distress may occur as a consequence of poorer cognitive functioning in elderly, but not vice versa. The lack of correlation between objective and subjective cognitive measures suggested that the participants may not have adequate insight into their cognitive abilities. The implications of these findings are discussed. Copyright © 2018. Published by Elsevier B.V.

  19. Handling Qualities of a Large Civil Tiltrotor in Hover using Translational Rate Command

    NASA Technical Reports Server (NTRS)

    Malpica, Carlos A.; Theodore, Colin R.; Lawrence, Ben; Lindsey, James; Blanken, Chris

    2012-01-01

    A Translational Rate Command (TRC) control law has been developed to enable low speed maneuvering of a large civil tiltrotor with minimal pitch changes by means of automatic nacelle angle deflections for longitudinal velocity control. The nacelle actuator bandwidth required to achieve Level 1 handling qualities in hover and the feasibility of additional longitudinal cyclic control to augment low bandwidth nacelle actuation were investigated. A frequency-domain handling qualities criterion characterizing TRC response in terms of bandwidth and phase delay was proposed and validated against a piloted simulation conducted on the NASA-Ames Vertical Motion Simulator. Seven experimental test pilots completed evaluations in the ADS-33E-PRF Hover Mission Task Element (MTE) for a matrix of nacelle actuator bandwidths, equivalent rise times and control response sensitivities, and longitudinal cyclic control allocations. Evaluated against this task, longitudinal phase delay shows the Level 1 boundary is around 0.4 0.5 s. Accordingly, Level 1 handling qualities were achieved either with a nacelle actuator bandwidth greater than 4 rad/s, or by employing longitudinal cyclic control to augment low bandwidth nacelle actuation.

  20. Deadlines at work and sleep quality. Cross-sectional and longitudinal findings among Danish knowledge workers.

    PubMed

    Rugulies, Reiner; Martin, Marie H T; Garde, Anne Helene; Persson, Roger; Albertsen, Karen

    2012-03-01

    Exposure to deadlines at work is increasing in several countries and may affect health. We aimed to investigate cross-sectional and longitudinal associations between frequency of difficult deadlines at work and sleep quality. Study participants were knowledge workers, drawn from a representative sample of Danish employees who responded to a baseline questionnaire in 2006 (n = 363) and a follow-up questionnaire in 2007 (n = 302). Frequency of difficult deadlines was measured by self-report and categorized into low, intermediate, and high. Sleep quality was measured with a Total Sleep Quality Score and two indexes (Awakening Index and Disturbed Sleep Index) derived from the Karolinska Sleep Questionnaire. Analyses on the association between frequency of deadlines and sleep quality scores were conducted with multiple linear regression models, adjusted for potential confounders. In addition, we used multiple logistic regression models to analyze whether frequency of deadlines at baseline predicted caseness of sleep problems at follow-up among participants free of sleep problems at baseline. Frequent deadlines were cross-sectionally and longitudinally associated with poorer sleep quality on all three sleep quality measures. Associations in the longitudinal analyses were greatly attenuated when we adjusted for baseline sleep quality. The logistic regression analyses showed that frequent deadlines at baseline were associated with elevated odds ratios for caseness of sleep problems at follow-up, however, confidence intervals were wide in these analyses. Frequent deadlines at work were associated with poorer sleep quality among Danish knowledge workers. We recommend investigating the relation between deadlines and health endpoints in large-scale epidemiologic studies. Copyright © 2011 Wiley Periodicals, Inc.

  1. Meal pattern among Norwegian primary-school children and longitudinal associations between meal skipping and weight status.

    PubMed

    Stea, Tonje H; Vik, Frøydis N; Bere, Elling; Svendsen, Martin V; Oellingrath, Inger M

    2015-02-01

    To investigate meal pattern longitudinally and explore whether meal skipping was associated with overweight among Norwegian children and adolescents. Longitudinal study. Children's meal frequencies were reported by their parents using a retrospective FFQ. Weight and height were measured by public health nurses. Descriptive data comparing 4th and 7th grade were analysed by paired-sample t tests for continuous variables and χ 2 tests for categorical variables. Odds ratio estimates, including confidence intervals, with BMI category (normal/overweight) as the dependent variable, were determined through logistic regression analyses. Primary schools, Telemark County, Norway. A cohort of 428 Norwegian boys and girls; 4th graders in 2007, 7th graders in 2010. The number of children eating four main meals per day (regular meal frequency) decreased from 4th grade (47 %) to 7th grade (38 %; P = 0·001). Those who ate regular meals in 4th grade but not in 7th grade had higher odds (OR = 3·1; 95 % CI 1·1, 9·0) of being overweight in 7th grade after adjusting for gender, maternal education and physical activity, but the odds ratio was not statistically significant after adjusting for overweight in 4th grade (OR = 2·8; 95 % CI 0·7, 11·6). The present study showed significant increases in overall meal skipping among children between 4th and 7th grade. The results indicate an association between overweight and meal skipping, but additional prospective and longitudinal analyses and intervention trials are warranted to confirm this relationship.

  2. Child incarceration and long-term adult health outcomes: a longitudinal study.

    PubMed

    Barnert, Elizabeth S; Abrams, Laura S; Tesema, Lello; Dudovitz, Rebecca; Nelson, Bergen B; Coker, Tumaini; Bath, Eraka; Biely, Christopher; Li, Ning; Chung, Paul J

    2018-03-12

    Purpose Although incarceration may have life-long negative health effects, little is known about associations between child incarceration and subsequent adult health outcomes. The paper aims to discuss this issue. Design/methodology/approach The authors analyzed data from 14,689 adult participants in the National Longitudinal Study of Adolescent to Adult Health (Add Health) to compare adult health outcomes among those first incarcerated between 7 and 13 years of age (child incarceration); first incarcerated at>or=14 years of age; and never incarcerated. Findings Compared to the other two groups, those with a history of child incarceration were disproportionately black or Hispanic, male, and from lower socio-economic strata. Additionally, individuals incarcerated as children had worse adult health outcomes, including general health, functional limitations (climbing stairs), depressive symptoms, and suicidality, than those first incarcerated at older ages or never incarcerated. Research limitations/implications Despite the limitations of the secondary database analysis, these findings suggest that incarcerated children are an especially medically vulnerable population. Practical implications Programs and policies that address these medically vulnerable children's health needs through comprehensive health and social services in place of, during, and/or after incarceration are needed. Social implications Meeting these unmet health and social service needs offers an important opportunity to achieve necessary health care and justice reform for children. Originality/value No prior studies have examined the longitudinal relationship between child incarceration and adult health outcomes.

  3. The Categorical Stability of Gambling Motives Among Community-Recruited Gamblers: A Longitudinal Assessment.

    PubMed

    McGrath, Daniel S; Konkolÿ Thege, Barna

    2018-03-01

    Over the past decade, several motivational models have been proposed to explain the role of motives in gambling disorder. In the model captured by the four-factor Gambling Motives Questionnaire Financial (GMQ-F), gamblers are described as being primarily motivated to gamble for 'coping', 'enhancement', 'social', and 'financial' reasons. Although this model has received significant empirical support; to date, research assessing the role of motives in gambling disorder has been primarily cross-sectional in nature. Thus, the extent to which gambling motives remain stable over time has yet to be explored. In the current study, the stability versus fluidity of self-assessed gambling motives was investigated using the Quinte Longitudinal Study, a longitudinal dataset of gambling behaviour collected over 5 years. Gambling motives of 2795 gamblers were examined over all five annual assessments. The total proportion of gamblers who stayed in the same primary motive category across each of the 5 consecutive assessments was 22%, indicating substantial fluidity in category membership. Substantial movement between categories was seen for each GMQ-F group, as well as an additional group of non-classified motives. Logistic regression analyses suggest that greater resistance to gambling fallacies significantly predicted stability between the baseline assessment and a follow-up 1 year later, but gambling severity did not. Potential limitations in the study design and opportunities for future research are discussed.

  4. Brief Intervention for Truant Youth Sexual Risk Behavior and Alcohol Use: A Parallel Process Growth Model Analysis

    PubMed Central

    Dembo, Richard; Briones-Robinson, Rhissa; Ungaro, Rocio; Barrett, Kimberly; Gulledge, Laura; Winters, Ken C.; Belenko, Steven; Karas, Lora M.; Wareham, Jennifer

    2011-01-01

    Truant youths represent a challenging, yet very promising group of at-risk youth to study. In addition to problems in school, they frequently experience troubled family situations, emotional/ psychological problems, involvement in substance use, and delinquency. Given the problems often experienced by truant youth, it is likely they are engaging in alcohol use and sexual risk behavior at a higher rate, than the general youth population. Identification of these youths’ problems and early placement into effective intervention services would benefit them, their families, and society. The current study presents interim findings from an ongoing, NIDA-funded experimental, Brief Intervention (BI) study involving truant youths and their parent/guardians. Baseline, 3-month, 6-month, and 12-month follow up data were analyzed to determine whether alcohol use and sexual risk behaviors were longitudinally related, examine the effects of the intervention on longitudinal alcohol use and sexual risk behaviors, identify latent subgroups of youths in the data for alcohol use and sexual risk behaviors, and determine whether the intervention influenced these subgroups. Results indicated alcohol use and sexual risk were longitudinally related. Subgroups of youth were also identified based on alcohol use and sexual risk behavior levels and trends. Further, limited treatment effects were observed for alcohol use. Implications of the results for future research and service delivery are considered. PMID:25242878

  5. Depression and fatigue in patients with multiple sclerosis.

    PubMed

    Greeke, Emily E; Chua, Alicia S; Healy, Brian C; Rintell, David J; Chitnis, Tanuja; Glanz, Bonnie I

    2017-09-15

    Previous research has examined the components of depression and fatigue in multiple sclerosis (MS), but the findings have been inconsistent. The aim of this study was to explore the associations between overall and subscale scores of the Center for Epidemiologic Studies-Depression Scale (CES-D) and the Modified Fatigue Impact Scale (MFIS) as well as the longitudinal changes in scores in a large cohort of MS patients. MS subjects who completed a battery of patient reported outcome (PRO) measures including the CES-D and MFIS (N=435) were included in our analysis. At the first available MFIS measurement, Pearson's correlation coefficient was used to estimate the association between the CES-D and MFIS in terms of both total scores and subscale scores. In addition, the longitudinal change in each total score and subscale score was estimated using a linear mixed model, and the association between the measures in terms of longitudinal change was estimated using Pearson's correlation coefficient and linear mixed models. At baseline, 15% of subjects were classified as high on both depression and fatigue scales, 16% were classified as high on the fatigue scale only, and 9% were classified as high on the depression scale only. There was a high correlation between CES-D and MFIS total scores (r=0.62). High correlations were also observed between the somatic and retarded activity subscales of the CES-D and each of the MFIS subscales (r≥0.60). In terms of longitudinal change, the change over the first year between the CES-D and MFIS total scores showed a moderate correlation (r=0.49). Subjects with high fatigue scores but low depression scores at baseline were more likely than subjects with low baseline fatigue and depression scores to develop high depression scores at follow-up. Our study demonstrated that depression and fatigue in MS share several features and have a similar longitudinal course. But using cut-off scores to define depression and fatigue, our study also found that non-depressed subjects with high fatigue may be at a greater risk for developing depression. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Effects of school start time on students' sleep duration, daytime sleepiness, and attendance: a meta-analysis.

    PubMed

    Bowers, Jennifer M; Moyer, Anne

    2017-12-01

    Research conducted over the past three decades finds that many children and adolescents do not meet recommended sleep guidelines. Lack of sleep is a predictor of a number of consequences, including issues at school such as sleepiness and tardiness. Considering the severity of this public health issue, it is essential to understand more about the factors that may compromise children's and adolescents' sleep. This meta-analysis examined the effects of school start time (SST) on sleep duration of students by aggregating the results of five longitudinal studies and 15 cross-sectional comparison group studies. Results indicated that later starting school times are associated with longer sleep durations. Additionally, later start times were associated with less daytime sleepiness (7 studies) and tardiness to school (3 studies). However, methodological considerations, such as a need for more longitudinal primary research, lead to a cautious interpretation. Overall, this systematic analysis of SST studies suggests that delaying SST is associated with benefits for students' sleep and, thus, their general well-being. Copyright © 2017 National Sleep Foundation. Published by Elsevier Inc. All rights reserved.

  7. Exploring Organizational Barriers to Strengthening Clinical Supervision of Psychiatric Nursing Staff: A Longitudinal Controlled Intervention Study.

    PubMed

    Gonge, Henrik; Buus, Niels

    2016-05-01

    This article reports findings from a longitudinal controlled intervention study of 115 psychiatric nursing staff. The twofold objective of the study was: (a) To test whether the intervention could increase clinical supervision participation and effectiveness of existing supervision practices, and (b) To explore organizational constraints to implementation of these strengthened practices. Questionnaire responses and registration of participation in clinical supervision were registered prior and subsequent to the intervention consisting of an action learning oriented reflection on staff's existing clinical supervision practices. Major organizational changes in the intervention group during the study period obstructed the implementation of strengthened clinical supervision practices, but offered an opportunity for studying the influences of organizational constraints. The main findings were that a) diminishing experience of social support from colleagues was associated with reduced participation in clinical supervision, while b) additional quantitative demands were associated with staff reporting difficulties finding time for supervision. This probably explained a negative development in the experienced effectiveness of supervision. It is concluded that organizational support is an imperative for implementation of clinical supervision.

  8. Improved longitudinal gray and white matter atrophy assessment via application of a 4-dimensional hidden Markov random field model.

    PubMed

    Dwyer, Michael G; Bergsland, Niels; Zivadinov, Robert

    2014-04-15

    SIENA and similar techniques have demonstrated the utility of performing "direct" measurements as opposed to post-hoc comparison of cross-sectional data for the measurement of whole brain (WB) atrophy over time. However, gray matter (GM) and white matter (WM) atrophy are now widely recognized as important components of neurological disease progression, and are being actively evaluated as secondary endpoints in clinical trials. Direct measures of GM/WM change with advantages similar to SIENA have been lacking. We created a robust and easily-implemented method for direct longitudinal analysis of GM/WM atrophy, SIENAX multi-time-point (SIENAX-MTP). We built on the basic halfway-registration and mask composition components of SIENA to improve the raw output of FMRIB's FAST tissue segmentation tool. In addition, we created LFAST, a modified version of FAST incorporating a 4th dimension in its hidden Markov random field model in order to directly represent time. The method was validated by scan-rescan, simulation, comparison with SIENA, and two clinical effect size comparisons. All validation approaches demonstrated improved longitudinal precision with the proposed SIENAX-MTP method compared to SIENAX. For GM, simulation showed better correlation with experimental volume changes (r=0.992 vs. 0.941), scan-rescan showed lower standard deviations (3.8% vs. 8.4%), correlation with SIENA was more robust (r=0.70 vs. 0.53), and effect sizes were improved by up to 68%. Statistical power estimates indicated a potential drop of 55% in the number of subjects required to detect the same treatment effect with SIENAX-MTP vs. SIENAX. The proposed direct GM/WM method significantly improves on the standard SIENAX technique by trading a small amount of bias for a large reduction in variance, and may provide more precise data and additional statistical power in longitudinal studies. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Asthma Education and Intervention Program: Partnership for Asthma Trigger-Free Homes (PATH)

    DTIC Science & Technology

    2008-08-01

    military setting if additional funding is procured.) 15. SUBJECT TERMS Asthma , longitudinal study, asthma education, indoor asthma triggers, dust...caregiver quality of life, we make use of the Juniper Pediatric Asthma Caregiver’s Quality of Life questionnaire (PACQLQ). It measures the problems that...whose reliability and validity are described below. We employ the Juniper Pediatric Asthma Caregiver’s Quality of Life questionnaire (PACQLQ) to measure

  10. Noninvasive imaging of experimental lung fibrosis.

    PubMed

    Zhou, Yong; Chen, Huaping; Ambalavanan, Namasivayam; Liu, Gang; Antony, Veena B; Ding, Qiang; Nath, Hrudaya; Eary, Janet F; Thannickal, Victor J

    2015-07-01

    Small animal models of lung fibrosis are essential for unraveling the molecular mechanisms underlying human fibrotic lung diseases; additionally, they are useful for preclinical testing of candidate antifibrotic agents. The current end-point measures of experimental lung fibrosis involve labor-intensive histological and biochemical analyses. These measures fail to account for dynamic changes in the disease process in individual animals and are limited by the need for large numbers of animals for longitudinal studies. The emergence of noninvasive imaging technologies provides exciting opportunities to image lung fibrosis in live animals as often as needed and to longitudinally track the efficacy of novel antifibrotic compounds. Data obtained by noninvasive imaging provide complementary information to histological and biochemical measurements. In addition, the use of noninvasive imaging in animal studies reduces animal usage, thus satisfying animal welfare concerns. In this article, we review these new imaging modalities with the potential for evaluation of lung fibrosis in small animal models. Such techniques include micro-computed tomography (micro-CT), magnetic resonance imaging, positron emission tomography (PET), single photon emission computed tomography (SPECT), and multimodal imaging systems including PET/CT and SPECT/CT. It is anticipated that noninvasive imaging will be increasingly used in animal models of fibrosis to gain insights into disease pathogenesis and as preclinical tools to assess drug efficacy.

  11. DC-9 Flight Demonstration Program with Refanned JT8D Engines. Volume 3; Performance and Analysis

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The JT8D-109 engine has a sea level static, standard day bare engine takeoff thrust of 73,840 N. At sea level standard day conditions the additional thrust of the JT8D-109 results in 2,040 kg additional takeoff gross weight capability for a given field length. Range loss of the DC-9 Refan airplane for long range cruise was determined. The Refan airplane demonstrated stall, static longitudinal stability, longitudinal control, longitudinal trim, minimum control speeds, and directional control characteristics similar to the DC-9-30 production airplane and complied with airworthiness requirements. Cruise, climb, and thrust reverser performance were evaluated. Structural and dynamic ground test, flight test and analytical results substantiate Refan Program requirements that the nacelle, thrust reverser hardware, and the airplane structural modifications are flightworthy and certifiable and that the airplane meets flutter speed margins. Estimated unit cost of a DC-9 Refan retrofit program is 1.338 million in mid-1975 dollars with about an equal split in cost between airframe and engine.

  12. Efficacy of hormonal and mental treatments with MMPI in FtM individuals: cross-sectional and longitudinal studies.

    PubMed

    Oda, Hiroyuki; Kinoshita, Toshihiko

    2017-07-17

    Cross-sex hormone treatment (CSHT) is an important option for gender dysphoria (GD) individuals to improve the quality of life. However, in Japan, sex reassignment surgery (SRS) and CSHT for GD had been discontinued until 1998 (over 30 years). After resumption, the number of GD individuals wishing treatment rapidly increased. On the other hand, the number of medical institutions available for evaluation was limited. For this reason, hormonal treatment has been administered to GD individuals requiring the prompt start of CSHT in the absence of mental health assessment by specialists. In this study, we examined the efficacy of CSHT and psychotherapy. The participants were 155 female-to-male (FtM) individuals who consulted our gender identity clinic, and were definitively diagnosed. A cross-sectional study was conducted by dividing them into two groups: groups with and without CSHT on the initial consultation (Group CSHT: n = 53, Group no-CSHT: n = 102). In all participants, Minnesota Multiphasic Personality Inventory (MMPI) and blood hormone tests were performed on the initial consultation. In addition, CSHT was combined with psychotherapy for a specific period in Group no-CSHT, and FtM individuals in whom an additional MMPI test could be conducted (Group combined treatment (CT), n = 14) were enrolled in a longitudinal study. In the cross-sectional study, there was no significant difference on the MMPI test. In the longitudinal study, there were improvements in the clinical scales other than the Mf scale on the MMPI test. In Group CT, the D, Sc, and Si scale scores on the initial consultation were significantly higher than in Group CSHT. However, there was no clinical scale with a significantly higher value after the start of treatment. The Pd scale score was significantly lower. CSHT improved mental health. Psychotherapy-combined CSHT may further improve it. The study was reviewed and approved by the Ethics Committee of Kansai Medical University (A comprehensive treatment for gender dysphoria: No. 0314 registered date 10th December 2003), and was approved at UMIN000028102 on 6th July 2017 as retrospectively registered.

  13. A Longitudinal Examination of Childhood Maltreatment and Adolescent Obesity: Results from the National Longitudinal Study of Adolescent Health (AddHealth) Study

    ERIC Educational Resources Information Center

    Shin, Sunny Hyucksun; Miller, Daniel P.

    2012-01-01

    Objectives: We sought to explore the association between childhood maltreatment (e.g., neglect, physical and sexual abuse) and longitudinal growth trajectories of body mass index (BMI) from adolescence to young adulthood. Methods: We used latent curve modeling to examine data from the National Longitudinal Study of Adolescent Health (N = 8,471),…

  14. Coping with Memory Effect and Serial Correlation when Estimating Reliability in a Longitudinal Framework

    ERIC Educational Resources Information Center

    Laenen, Annouschka; Alonso, Ariel; Molenberghs, Geert; Vangeneugden, Tony; Mallinckrodt, Craig H.

    2010-01-01

    Longitudinal studies are permeating clinical trials in psychiatry. Therefore, it is of utmost importance to study the psychometric properties of rating scales, frequently used in these trials, within a longitudinal framework. However, intrasubject serial correlation and memory effects are problematic issues often encountered in longitudinal data.…

  15. Human longevity and variation in GH/IGF-1/insulin signaling, DNA damage signaling and repair and pro/antioxidant pathway genes: cross sectional and longitudinal studies.

    PubMed

    Soerensen, Mette; Dato, Serena; Tan, Qihua; Thinggaard, Mikael; Kleindorp, Rabea; Beekman, Marian; Jacobsen, Rune; Suchiman, H Eka D; de Craen, Anton J M; Westendorp, Rudi G J; Schreiber, Stefan; Stevnsner, Tinna; Bohr, Vilhelm A; Slagboom, P Eline; Nebel, Almut; Vaupel, James W; Christensen, Kaare; McGue, Matt; Christiansen, Lene

    2012-05-01

    Here we explore association with human longevity of common genetic variation in three major candidate pathways: GH/IGF-1/insulin signaling, DNA damage signaling and repair and pro/antioxidants by investigating 1273 tagging SNPs in 148 genes composing these pathways. In a case-control study of 1089 oldest-old (age 92-93) and 736 middle-aged Danes we found 1 pro/antioxidant SNP (rs1002149 (GSR)), 5 GH/IGF-1/INS SNPs (rs1207362 (KL), rs2267723 (GHRHR), rs3842755 (INS), rs572169 (GHSR), rs9456497 (IGF2R)) and 5 DNA repair SNPs (rs11571461 (RAD52), rs13251813 (WRN), rs1805329 (RAD23B), rs2953983 (POLB), rs3211994 (NTLH1)) to be associated with longevity after correction for multiple testing. In a longitudinal study with 11 years of follow-up on survival in the oldest-old Danes we found 2 pro/antioxidant SNPs (rs10047589 (TNXRD1), rs207444 (XDH)), 1 GH/IGF-1/INS SNP (rs26802 (GHRL)) and 3 DNA repair SNPs (rs13320360 (MLH1), rs2509049 (H2AFX) and rs705649 (XRCC5)) to be associated with mortality in late life after correction for multiple testing. When examining the 11 SNPs from the case-control study in the longitudinal data, rs3842755 (INS), rs13251813 (WRN) and rs3211994 (NTHL1) demonstrated the same directions of effect (p<0.05), while rs9456497 (IGF2R) and rs1157146 (RAD52) showed non-significant tendencies, indicative of effects also in late life survival. In addition, rs207444 (XDH) presented the same direction of effect when inspecting the 6 SNPs from the longitudinal study in the case-control data, hence, suggesting an effect also in survival from middle age to old age. No formal replications were observed when investigating the 11 SNPs from the case-control study in 1613 oldest-old (age 95-110) and 1104 middle-aged Germans, although rs11571461 (RAD52) did show a supportive non-significant tendency (OR=1.162, 95% CI=0.927-1.457). The same was true for rs10047589 (TNXRD1) (HR=0.758, 95%CI=0.543-1.058) when examining the 6 SNPs from the longitudinal study in a Dutch longitudinal cohort of oldest-old (age 85+, N=563). In conclusion, the present candidate gene based association study, the largest to date applying a pathway approach, not only points to potential new longevity loci, but also underlines the difficulties of replicating association findings in independent study populations and thus the difficulties in identifying universal longevity polymorphisms. Copyright © 2012 Elsevier Inc. All rights reserved.

  16. Modeling of Dipole and Quadrupole Fringe-Field Effects for the Advanced Photon Source Upgrade Lattice

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Borland, M.; Lindberg, R.

    2017-06-01

    The proposed upgrade of the Advanced Photon Source (APS) to a multibend-achromat lattice requires shorter and much stronger quadrupole magnets than are present in the existing ring. This results in longitudinal gradient profiles that differ significantly from a hard-edge model. Additionally, the lattice assumes the use of five-segment longitudinal gradient dipoles. Under these circumstances, the effects of fringe fields and detailed field distributions are of interest. We evaluated the effect of soft-edge fringe fields on the linear optics and chromaticity, finding that compensation for these effects is readily accomplished. In addition, we evaluated the reliability of standard methods of simulatingmore » hardedge nonlinear fringe effects in quadrupoles.« less

  17. The linear relationship between the Vulnerable Elders Survey-13 score and mortality in an Asian population of community-dwelling older persons.

    PubMed

    Wang, Jye; Lin, Wender; Chang, Ling-Hui

    2018-01-01

    The Vulnerable Elders Survey-13 (VES-13) has been used as a screening tool to identify vulnerable community-dwelling older persons for more in-depth assessment and targeted interventions. Although many studies supported its use in different populations, few have addressed Asian populations. The optimal scaling system for the VES-13 in predicting health outcomes also has not been adequately tested. This study (1) assesses the applicability of the VES-13 to predict the mortality of community-dwelling older persons in Taiwan, (2) identifies the best scaling system for the VES-13 in predicting mortality using generalized additive models (GAMs), and (3) determines whether including covariates, such as socio-demographic factors and common geriatric syndromes, improves model fitting. This retrospective longitudinal cohort study analyzed the data of 2184 community-dwelling persons 65 years old or older from the 2003 wave of the national-wide Taiwan Longitudinal Study on Aging. Cox proportional hazards models and Generalized Additive Models (GAMs) were used. The VES-13 significantly predicted the mortality of Taiwan's community-dwelling elders. A one-point increase in the VES-13 score raised the risk of death by 26% (hazard ratio, 1.26; 95% confidence interval, 1.21-1.32). The hazard ratio of death increased linearly with each additional VES-13 score point, suggesting that using a continuous scale is appropriate. Inclusion of socio-demographic factors and geriatric syndromes improved the model-fitting. The VES-13 is appropriate for an Asian population. VES-13 scores linearly predict the mortality of this population. Adjusting the weighting of the physical activity items may improve the performance of the VES-13. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Effects of Harsh and Unpredictable Environments in Adolescence on Development of Life History Strategies

    PubMed Central

    Figueredo, Aurelio José; Ellis, Bruce J.

    2010-01-01

    The National Longitudinal Study of Adolescent Health data were used to test predictions from life history theory. We hypothesized that (1) in young adulthood an emerging life history strategy would exist as a common factor underlying many life history traits (e.g., health, relationship stability, economic success), (2) both environmental harshness and unpredictability would account for unique variance in expression of adolescent and young adult life history strategies, and (3) adolescent life history traits would predict young adult life history strategy. These predictions were supported. The current findings suggest that the environmental parameters of harshness and unpredictability have concurrent effects on life history development in adolescence, as well as longitudinal effects into young adulthood. In addition, life history traits appear to be stable across developmental time from adolescence into young adulthood. PMID:20634914

  19. Data-driven regions of interest for longitudinal change in frontotemporal lobar degeneration.

    PubMed

    Pankov, Aleksandr; Binney, Richard J; Staffaroni, Adam M; Kornak, John; Attygalle, Suneth; Schuff, Norbert; Weiner, Michael W; Kramer, Joel H; Dickerson, Bradford C; Miller, Bruce L; Rosen, Howard J

    2016-01-01

    Current research is investigating the potential utility of longitudinal measurement of brain structure as a marker of drug effect in clinical trials for neurodegenerative disease. Recent studies in Alzheimer's disease (AD) have shown that measurement of change in empirically derived regions of interest (ROIs) allows more reliable measurement of change over time compared with regions chosen a-priori based on known effects of AD on brain anatomy. Frontotemporal lobar degeneration (FTLD) is a devastating neurodegenerative disorder for which there are no approved treatments. The goal of this study was to identify an empirical ROI that maximizes the effect size for the annual rate of brain atrophy in FTLD compared with healthy age matched controls, and to estimate the effect size and associated power estimates for a theoretical study that would use change within this ROI as an outcome measure. Eighty six patients with FTLD were studied, including 43 who were imaged twice at 1.5 T and 43 at 3 T, along with 105 controls (37 imaged at 1.5 T and 67 at 3 T). Empirically-derived maps of change were generated separately for each field strength and included the bilateral insula, dorsolateral, medial and orbital frontal, basal ganglia and lateral and inferior temporal regions. The extent of regions included in the 3 T map was larger than that in the 1.5 T map. At both field strengths, the effect sizes for imaging were larger than for any clinical measures. At 3 T, the effect size for longitudinal change measured within the empirically derived ROI was larger than the effect sizes derived from frontal lobe, temporal lobe or whole brain ROIs. The effect size derived from the data-driven 1.5 T map was smaller than at 3 T, and was not larger than the effect size derived from a-priori ROIs. It was estimated that measurement of longitudinal change using 1.5 T MR systems requires approximately a 3-fold increase in sample size to obtain effect sizes equivalent to those seen at 3 T. While the results should be confirmed in additional datasets, these results indicate that empirically derived ROIs can reduce the number of subjects needed for a longitudinal study of drug effects in FTLD compared with a-priori ROIs. Field strength may have a significant impact on the utility of imaging for measuring longitudinal change.

  20. Use of missing data methods in longitudinal studies: the persistence of bad practices in developmental psychology.

    PubMed

    Jelicić, Helena; Phelps, Erin; Lerner, Richard M

    2009-07-01

    Developmental science rests on describing, explaining, and optimizing intraindividual changes and, hence, empirically requires longitudinal research. Problems of missing data arise in most longitudinal studies, thus creating challenges for interpreting the substance and structure of intraindividual change. Using a sample of reports of longitudinal studies obtained from three flagship developmental journals-Child Development, Developmental Psychology, and Journal of Research on Adolescence-we examined the number of longitudinal studies reporting missing data and the missing data techniques used. Of the 100 longitudinal studies sampled, 57 either reported having missing data or had discrepancies in sample sizes reported for different analyses. The majority of these studies (82%) used missing data techniques that are statistically problematic (either listwise deletion or pairwise deletion) and not among the methods recommended by statisticians (i.e., the direct maximum likelihood method and the multiple imputation method). Implications of these results for developmental theory and application, and the need for understanding the consequences of using statistically inappropriate missing data techniques with actual longitudinal data sets, are discussed.

  1. Longitudinal study of arteriogenesis with swept source optical coherence tomography and hyperspectral imaging

    NASA Astrophysics Data System (ADS)

    Poole, Kristin M.; Patil, Chetan A.; Nelson, Christopher E.; McCormack, Devin R.; Madonna, Megan C.; Duvall, Craig L.; Skala, Melissa C.

    2014-03-01

    Peripheral arterial disease (PAD) is an atherosclerotic disease of the extremities that leads to high rates of myocardial infarction and stroke, increased mortality, and reduced quality of life. PAD is especially prevalent in diabetic patients, and is commonly modeled by hind limb ischemia in mice to study collateral vessel development and test novel therapies. Current techniques used to assess recovery cannot obtain quantitative, physiological data non-invasively. Here, we have applied hyperspectral imaging and swept source optical coherence tomography (OCT) to study longitudinal changes in blood oxygenation and vascular morphology, respectively, intravitally in the diabetic mouse hind limb ischemia model. Additionally, recommended ranges for controlling physiological variability in blood oxygenation with respect to respiration rate and body core temperature were determined from a control animal experiment. In the longitudinal study with diabetic mice, hyperspectral imaging data revealed the dynamics of blood oxygenation recovery distally in the ischemic footpad. In diabetic mice, there is an early increase in oxygenation that is not sustained in the long term. Quantitative analysis of vascular morphology obtained from Hessian-filtered speckle variance OCT volumes revealed temporal dynamics in vascular density, total vessel length, and vessel diameter distribution in the adductor muscle of the ischemic limb. The combination of hyperspectral imaging and speckle variance OCT enabled acquisition of novel functional and morphological endpoints from individual animals, and provides a more robust platform for future preclinical evaluations of novel therapies for PAD.

  2. In vivo longitudinal MRI and behavioral studies in experimental spinal cord injury.

    PubMed

    Sundberg, Laura M; Herrera, Juan J; Narayana, Ponnada A

    2010-10-01

    Comprehensive in vivo longitudinal studies that include multi-modal magnetic resonance imaging (MRI) and a battery of behavioral assays to assess functional outcome were performed at multiple time points up to 56 days post-traumatic spinal cord injury (SCI) in rodents. The MRI studies included high-resolution structural imaging for lesion volumetry, and diffusion tensor imaging (DTI) for probing the white matter integrity. The behavioral assays included open-field locomotion, grid walking, inclined plane, computerized activity box performance, and von Frey filament tests. Additionally, end-point histology was assessed for correlation with both the MRI and behavioral data. The temporal patterns of the lesions were documented on structural MRI. DTI studies showed significant changes in white matter that is proximal to the injury epicenter and persisted to day 56. White matter in regions up to 1 cm away from the injury epicenter that appeared normal on conventional MRI also exhibited changes that were indicative of tissue damage, suggesting that DTI is a more sensitive measure of the evolving injury. Correlations between DTI and histology after SCI could not be firmly established, suggesting that injury causes complex pathological changes in multiple tissue components that affect the DTI measures. Histological evidence confirmed a significant decrease in myelin and oligodendrocyte presence 56 days post-SCI. Multiple assays to evaluate aspects of functional recovery correlated with histology and DTI measures, suggesting that damage to specific white matter tracts can be assessed and tracked longitudinally after SCI.

  3. A Study of the Factors Associated with Risk for Development of Pressure Ulcers: A Longitudinal Analysis.

    PubMed

    Thomas, Elizebeth; Vinodkumar, Sudhaya; Mathew, Silvia; Setia, Maninder Singh

    2015-01-01

    Pressure ulcers (PUs) are prevalent in hospitalized patients; they may cause clinical, psychological, and economic problems in these patients. Previous studies are cross-sectional, have used pooled data, or cox-regression models to assess the risk for developing PU. However, PU risk scores change over time and models that account for time varying variables are useful for cohort analysis of data. The present longitudinal study was conducted to compare the risk of PU between surgical and nonsurgical patients, and to evaluate the factors associated with the development of these ulcers over a period of time. We evaluated 290 hospitalized patients over a 4 months period. The main outcomes for our analysis were: (1) Score on the pressure risk assessment scale; and (2) the proportion of individuals who were at severe risk for developing PUs. We used random effects models for longitudinal analysis of the data. The mean PU score was significantly higher in the nonsurgical patients compared with surgical patients at baseline (15.23 [3.86] vs. 9.33 [4.57]; P < 0.01). About 7% of the total patients had a score of >20 at baseline and were considered as being at high-risk for PU; the proportion was significantly higher among the nonsurgical patients compared with the surgical patients (14% vs. 4%, P = 0.003). In the adjusted models, there was no difference for severe risk for PU between surgical and nonsurgical patients (odds ratios [ORs]: 0.37, 95% confidence interval [CI]: 0.01-12.80). An additional day in the ward was associated with a significantly higher likelihood of being at high-risk for PU (OR: 1.47, 95% CI: 1.16-1.86). There were no significant differences between patients who were admitted for surgery compared with those who were not. An additional day in the ward, however, is important for developing a high-risk score for PU on the monitoring scale, and these patients require active interventions.

  4. Cognitive complaints mediate the effect of cognition on emotional stability across 12 years in old age.

    PubMed

    Aschwanden, Damaris; Kliegel, Matthias; Allemand, Mathias

    2018-05-01

    Previous research supports a positive relationship between cognition and emotional stability, although findings regarding healthy older adults are inconsistent. Additionally, little is known about the mechanisms that underlie this association. Thus, the present study investigated the mediating effect of cognitive complaints on the bidirectional longitudinal association between cognition and emotional stability in old age. The study sample consisted of 500 older individuals (M age = 62.97 years, SD = 0.91, range = 60-64 years; 52% male) from the Interdisciplinary Longitudinal Study on Adult Development. The results showed that cognitive complaints mediated the effect of cognition on emotional stability over 12 years even when taking baseline emotional stability, baseline cognitive complaints, depressive affect, gender, sensory functioning, and objective and subjective health into account. However, cognitive complaints did not mediate the effect of emotional stability on cognition. The results of the current study emphasize the importance of investigating cognition as a predictor of personality traits, and indicate that cognitive resources may serve as a protective factor for emotional stability in old age. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  5. The longitudinal effects of emotion regulation on physical and psychological health: A latent growth analysis exploring the role of cognitive fusion in inflammatory bowel disease.

    PubMed

    Trindade, Inês A; Ferreira, Cláudia; Pinto-Gouveia, José

    2018-02-01

    This study thus aims to test differences between patients with inflammatory bowel disease (IBD) regarding IBD symptomatology, cognitive fusion, and psychological and physical health, as well as to explore whether the maladaptive emotion regulation process of cognitive fusion longitudinally impacts on the baseline and evolution of these outcomes over a period of 18 months. Participants include 116 IBD patients with a mean age of 36.76 (SD = 11.39) of both genders (69.83% females) that completed the self-report measures of interest in three different times, equally spaced 9 months apart, over a period of 18 months. Latent growth curve models were conducted using structural equation modelling to estimate the growth trajectory of the variables in study. Inflammatory bowel disease symptomatology and cognitive fusion's levels were negatively associated with psychological health and physical health's baseline levels. Furthermore, IBD symptomatology did not influence the growth of psychological health, while cognitive fusion did (β = .30, p = .007). The same result was found for physical health (β = .26, p = .024). These findings indicate that individuals with higher levels of cognitive fusion present lower levels of psychological health and physical health that tend to further decrease over the time through the effects of this maladaptive emotion regulation process. This study implies that it is of crucial importance to include psychotherapeutic interventions in the health care of patients with IBD. If successful, these interventions could represent decreases in the cost of IBD treatment and in the use of drugs with adverse side effects, in addition to improving patients' mental health and quality of life. Further implications for clinical and research work are discussed. Statement of contribution What is already known on this subject? Research has demonstrated the impact of emotion regulation on both physical and mental health. Nevertheless, the longitudinal effects of the specific emotion regulation process of cognitive fusion on physical and psychological health have never been explored. Additionally, no study has yet examined the causal role of emotion regulation in evolution of physical health in inflammatory bowel disease (IBD). What does this study add? Cognitive fusion longitudinally impacted on IBD patients' physical and mental health. These variables were measured over a period of 18 months. Treatment for IBD should include interventions aiming to diminish maladaptive emotion regulation. © 2017 The British Psychological Society.

  6. Determining the local origin of hydroxyl radical generation during phacoemulsification.

    PubMed

    Aust, Steven D; Terry, Scott; Hebdon, Thomas; Gunderson, Broc; Terry, Michael; Dimalanta, Ramon

    2011-06-01

    To determine the local origin of hydroxyl radicals during phacoemulsification using an ultrasonic phacoemulsification device that includes longitudinal and torsional modalities. Chemistry and Biochemistry Department, Utah State University, Logan, Utah, USA. Experimental study. Experiments were conducted using the Infiniti Vision System and Ozil handpiece. Hydroxyl radical concentrations during longitudinal and torsional phacoemulsification were quantitated as malondialdehyde (MDA) determined spectrophotometrically using the deoxyribose assay. The difference between the total concentration found in the aspirated solution at steady-state concentrations and the pre-aspirate levels deductively determined the concentration of MDA formed along the interior of the sonicating tip. The time to reach 50% of steady state as a function of reaction vessel volume was determined. The mean maximum for torsional ultrasound at 100% amplitude was 7.70 nM ± 0.38 (SD), 91.1% of which was generated outside the tip. During longitudinal ultrasound at 100% power, MDA concentration in the aspirated solution was 29.5 ± 0.3 nM, 71.6% of which was generated outside the tip. The time (seconds) to reach 50% of maximum for longitudinal ultrasound using 5 mL, 10 mL, and 20 mL reaction vessels was 12.6 ± 1.5, 21.0 ± 1.5, and 25.3 ± 3.4, respectively. Although a significantly greater proportion of the hydroxyl radicals generated during ultrasound modality were formed outside the phaco tip (91.1% torsional; 71.6% longitudinal), torsional ultrasound generated only about one-fourth the amount of MDA as longitudinal ultrasound in total and about one-third that generated outside the tip (7.02 nM versus 21.1 nM). No author has a financial or proprietary interest in any material or method mentioned. Additional disclosures are found in the footnotes. Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  7. Five-year course and outcome of dysthymic disorder: A prospective, naturalistic follow-up study.

    PubMed

    Klein, D N; Schwartz, J E; Rose, S; Leader, J B

    2000-06-01

    There have been few naturalistic follow-up studies of dysthymic disorder. This study describes the 5-year course and outcome of dysthymic disorder. The authors conducted a prospective, longitudinal follow-up study of 86 outpatients with early-onset dysthymic disorder and 39 outpatients with episodic major depressive disorder. Follow-ups, conducted 30 and 60 months after entry into the study, rated patients on the Longitudinal Interval Follow-Up Evaluation and the Modified Hamilton Rating Scale for Depression. The estimated 5-year recovery rate from dysthymic disorder was 52.9%. Among patients who recovered, the estimated risk of relapse was 45.2% during a mean of 23 months of observation. Patients with dysthymic disorder spent approximately 70% of the follow-up period meeting the full criteria for a mood disorder. During the course of the follow-up the patients with dysthymic disorder exhibited significantly greater levels of symptoms and lower functioning and were significantly more likely to attempt suicide and to be hospitalized than were patients with episodic major depressive disorder. Finally, among patients with dysthymic disorder who had never experienced a major depressive episode before entry into the study, the estimated risk of having a first lifetime major depressive episode was 76.9%. Dysthymic disorder is a chronic condition with a protracted course and a high risk of relapse. In addition, almost all patients with dysthymic disorder eventually develop superimposed major depressive episodes. Although patients with dysthymic disorder tend to show mild to moderate symptoms, from a longitudinal perspective, the condition is severe.

  8. Temporal Associations of Popularity and Alcohol Use Among Middle School Students

    PubMed Central

    Tucker, Joan S.; Miles, Jeremy N. V.; D’Amico, Elizabeth J.; Zhou, Annie J.; Green, Harold D.; Shih, Regina A.

    2012-01-01

    Purpose The goal of this study is to better understand the longitudinal cross-lagged associations between popularity, assessed through self-rating and peer nominations, and alcohol use among middle school students. Methods The analytic sample is 1,835 6th–8th grade students who were initially recruited from three California middle schools and surveyed in the fall and spring semesters of two academic years. Students reported on their background characteristics, past month alcohol use, and perceived popularity. Additionally, students provided school-based friendship nominations, which were used to calculate peer-nominated popularity. A cross-lagged regression approach within a structural equation modeling framework was used to examine the longitudinal relationship between popularity (self-rated and peer-nominated) and alcohol use. Results There was a statistically significant (p = 0.024) association between peer-nominated popularity and the probability of alcohol consumption at the subsequent survey, but not vice versa. Our results suggest that in a scenario where 8% of students are past month drinkers, each increase of 5 friendship nominations is associated with a 30% greater risk of being a current drinker at the next wave. We found no evidence of longitudinal associations between past month alcohol consumption and self-rated popularity. Conclusions Popularity is a risk factor for drinking during the middle school years, with peer-nominated popularity being more predictive of use than self-perceptions of popularity. To inform alcohol prevention efforts for middle school students, additional research is needed to better understand why adolescents with a larger number of school-based friendship ties are more inclined to drink. PMID:23260843

  9. Using multi-ring structure for suppression of mode competition in stable single-longitudinal-mode erbium fiber laser

    NASA Astrophysics Data System (ADS)

    Yeh, Chien-Hung; Huang, Tzu-Jung; Yang, Zi-Qing; Chow, Chi-Wai

    2017-12-01

    In this demonstration, a stable and tunable single-longitudinal-mode (SLM) erbium-doped fiber (EDF) laser with multiple-ring configuration is proposed and investigated. The proposed compound-ring structure can create different free spectrum ranges (FSRs) to result in the mode-filter effect based on the Vernier effect for suppressing the other modes. Additionally, the output stabilization of power and wavelength in the proposed EDF multiple-ring laser are also discussed.

  10. Shapiro steps for skyrmion motion on a washboard potential with longitudinal and transverse ac drives

    DOE PAGES

    Reichhardt, Charles; Reichhardt, Cynthia Jane

    2015-12-28

    In this work, we numerically study the behavior of two-dimensional skyrmions in the presence of a quasi-one-dimensional sinusoidal substrate under the influence of externally applied dc and ac drives. In the overdamped limit, when both dc and ac drives are aligned in the longitudinal direction parallel to the direction of the substrate modulation, the velocity-force curves exhibit classic Shapiro step features when the frequency of the ac drive matches the washboard frequency that is dynamically generated by the motion of the skyrmions over the substrate, similar to previous observations in superconducting vortex systems. In the case of skyrmions, the additionalmore » contribution to the skyrmion motion from a nondissipative Magnus force shifts the location of the locking steps to higher dc drives, and we find that the skyrmions move at an angle with respect to the direction of the dc drive. For a longitudinal dc drive and a perpendicular or transverse ac drive, the overdamped system exhibits no Shapiro steps; however, when a finite Magnus force is present, we find pronounced transverse Shapiro steps along with complex two-dimensional periodic orbits of the skyrmions in the phase-locked regimes. Both the longitudinal and transverse ac drives produce locking steps whose widths oscillate with increasing ac drive amplitude. We examine the role of collective skyrmion interactions and find that additional fractional locking steps occur for both longitudinal and transverse ac drives. Finally, at higher skyrmion densities, the system undergoes a series of dynamical order-disorder transitions, with the skyrmions forming a moving solid on the phase locking steps and a fluctuating dynamical liquid in regimes between the steps.« less

  11. Distribution of enkephalin-like immunoreactivity in the cat digestive tract.

    PubMed

    Bagnol, D; Henry, M; Cupo, A; Julé, Y

    1997-05-12

    Immunohistochemical investigations were carried out to determine the pattern of distribution of methionine- and leucine-enkephalin-like materials in the cat pylorus, duodenum, ileum and proximal and distal colon. The present results indicate that leucine-enkephalin-like materials are less densely distributed than methionine-enkephalin-like materials, but that the two patterns of distribution show some similarities. Considerable regional differences exist however in the distribution of these enkephalin-like materials in the muscular layers. In the duodenum, ileum and proximal colon, the immunoreactivity was mainly confined to the myenteric plexus and the circular muscle layer, where it was present in nerve cell bodies and in numerous fibres. In the longitudinal muscle and submucous layers, a few immunoreactive fibres were observed which sometimes surrounded blood vessels. In the pylorus and the distal colon, however, numerous immunoreactive fibres were observed in the longitudinal and circular muscle layers; the immunoreactivity was detected in the cell bodies of numerous myenteric plexus neurons but those of only a few submucous plexus neurons. In addition, the pylorus tissues contained immunoreactive plexi which were localized either within the longitudinal muscle or between the serosa and the longitudinal muscle layer. These plexi were connected to the myenteric plexus by immunoreactive nerve strands. In all the small intestinal segments studied, numerous immunoreactive varicosities were present in the deep muscular plexus, in the inner part of the circular muscle layer. Our results suggest that in cats, the nervous control of external muscular layers mediated by enkephalins shows regional differences. In the pylorus and the distal colon, it involves both the longitudinal and circular muscle layers, whereas in other intestinal segments, only the circular muscle layer is involved.

  12. Female breast cancer incidence among Asian and Western populations: more similar than expected.

    PubMed

    Sung, Hyuna; Rosenberg, Philip S; Chen, Wan-Qing; Hartman, Mikael; Lim, Wei-Yen; Chia, Kee Seng; Wai-Kong Mang, Oscar; Chiang, Chun-Ju; Kang, Daehee; Ngan, Roger Kai-Cheong; Tse, Lap Ah; Anderson, William F; Yang, Xiaohong R

    2015-07-01

    Previous reports suggested that female breast cancer is associated with earlier ages at onset among Asian than Western populations. However, most studies utilized cross-sectional analyses that may be confounded by calendar-period and/or birth cohort effects. We, therefore, considered a longitudinal (forward-looking) approach adjusted for calendar-period changes and conditioned upon birth cohort. Invasive female breast cancer data (1988-2009) were obtained from cancer registries in China, Hong Kong, South Korea, Taiwan, Singapore, and the United States. Age-period-cohort models were used to extrapolate longitudinal age-specific incidence rates for the 1920, 1944, and 1970 birth cohorts. Cross-sectional age-specific incidence rates rose continuously until age 80 years among US white women, but plateaued or decreased after age 50 years among Asian women. In contrast, longitudinal age-specific rates were proportional (similar) among all Asian countries and the United States with incidence rates rising continuously until age 80 years. The extrapolated estimates for the most recent cohorts in some Asian countries actually showed later ages at onset than in the United States. Additionally, over successive birth cohorts, the incidence rate ratios (IRRs) for the longitudinal curves converged (narrowed) between Asian and US white women. Similar longitudinal age-specific incidence rates along with converging IRRs indicate that the age effects for invasive breast cancer are more similar among Asian and Western populations than might be expected from a solely cross-sectional analysis. Indeed, the Asian breast cancer rates in recent generations are even surpassing the historically high rates in the United States, highlighting an urgent need for efficient prevention and treatment strategies among Asian populations. Published by Oxford University Press 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  13. Perception of patterns of musical beat distribution in phonological developmental dyslexia: significant longitudinal relations with word reading and reading comprehension.

    PubMed

    Goswami, Usha; Huss, Martina; Mead, Natasha; Fosker, Tim; Verney, John P

    2013-05-01

    In a recent study, we reported that the accurate perception of beat structure in music ('perception of musical meter') accounted for over 40% of the variance in single word reading in children with and without dyslexia (Huss et al., 2011). Performance in the musical task was most strongly associated with the auditory processing of rise time, even though beat structure was varied by manipulating the duration of the musical notes. Here we administered the same musical task a year later to 88 children with and without dyslexia, and used new auditory processing measures to provide a more comprehensive picture of the auditory correlates of the beat structure task. We also measured reading comprehension and nonword reading in addition to single word reading. One year later, the children with dyslexia performed more poorly in the musical task than younger children reading at the same level, indicating a severe perceptual deficit for musical beat patterns. They now also had significantly poorer perception of sound rise time than younger children. Longitudinal analyses showed that the musical beat structure task was a significant longitudinal predictor of development in reading, accounting for over half of the variance in reading comprehension along with a linguistic measure of phonological awareness. The non-linguistic musical beat structure task is an important independent longitudinal and concurrent predictor of variance in reading attainment by children. The different longitudinal versus concurrent associations between musical beat perception and auditory processing suggest that individual differences in the perception of rhythmic timing are an important shared neural basis for individual differences in children in linguistic and musical processing. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Defining SNAP by cross-sectional and longitudinal definitions of neurodegeneration.

    PubMed

    Wisse, L E M; Das, S R; Davatzikos, C; Dickerson, B C; Xie, S X; Yushkevich, P A; Wolk, D A

    2018-01-01

    Suspected non-Alzheimer's pathophysiology (SNAP) is a biomarker driven designation that represents a heterogeneous group in terms of etiology and prognosis. SNAP has only been identified by cross-sectional neurodegeneration measures, whereas longitudinal measures might better reflect "active" neurodegeneration and might be more tightly linked to prognosis. We compare neurodegeneration defined by cross-sectional 'hippocampal volume' only (SNAP/L-) versus both cross-sectional and longitudinal 'hippocampal atrophy rate' (SNAP/L+) and investigate how these definitions impact prevalence and the clinical and biomarker profile of SNAP in Mild Cognitive Impairment (MCI). 276 MCI patients from ADNI-GO/2 were designated amyloid "positive" (A+) or "negative" (A-) based on their florbetapir scan and neurodegeneration 'positive' or 'negative' based on cross-sectional hippocampal volume and longitudinal hippocampal atrophy rate. 74.1% of all SNAP participants defined by the cross-sectional definition of neurodegeneration also met the longitudinal definition of neurodegeneration, whereas 25.9% did not. SNAP/L+ displayed larger white matter hyperintensity volume, a higher conversion rate to dementia over 5 years and a steeper decline on cognitive tasks compared to SNAP/L- and the A- CN group. SNAP/L- had more abnormal values on neuroimaging markers and worse performance on cognitive tasks than the A- CN group, but did not show a difference in dementia conversion rate or longitudinal cognition. Using a longitudinal definition of neurodegeneration in addition to a cross-sectional one identifies SNAP participants with significant cognitive decline and a worse clinical prognosis for which cerebrovascular disease may be an important driver.

  15. The health benefits of secondary education in adolescents and young adults: An international analysis in 186 low-, middle- and high-income countries from 1990 to 2013.

    PubMed

    Viner, Russell M; Hargreaves, Dougal S; Ward, Joseph; Bonell, Chris; Mokdad, Ali H; Patton, George

    2017-12-01

    The health benefits of secondary education have been little studied. We undertook country-level longitudinal analyses of the impact of lengthening secondary education on health outcomes amongst 15-24 year olds. Exposures: average length of secondary and primary education from 1980 to 2013.Data/Outcomes: Country level adolescent fertility rate (AFR), HIV prevalence and mortality rate from 1989/90 to 2013 across 186 low-, middle- and high-income countries.Analysis: Longitudinal mixed effects models, entering secondary and primary education together, adjusted for time varying GDP and country income status. Longitudinal structural marginal models using inverse probability weighting (IPW) to take account of time varying confounding by primary education and GDP. Counterfactual scenarios of no change in secondary education since 1980/1990 were estimated from model coefficients for each outcome. Each additional year of secondary education decreased AFR by 8.4% in mixed effects models and 14.6% in IPW models independent of primary education and GDP. Counterfactual analyses showed the proportion of the reduction in adolescent fertility rate over the study period independently attributable to secondary education was 28% in low income countries. Each additional year of secondary education reduced mortality by 16.9% for 15-19 year and 14.8% for 20-24 year old young women and 11.4% for 15-19 year and 8.8% for 20-24 year old young men. Counterfactual scenarios suggested 12% and 23% of the mortality reduction for 15-19 and 20-24 year old young men was attributable to secondary education in low income countries. Each additional year of secondary education was associated with a 24.5% and 43.1% reduction in HIV prevalence amongst young men and women. The health benefits associated with secondary education were greater than those of primary education and were greatest amongst young women and those from low income countries. Secondary education has the potential to be a social vaccine across many outcomes in low and middle income countries.

  16. Externalizing problems, attention regulation, and household chaos: a longitudinal behavioral genetic study.

    PubMed

    Wang, Zhe; Deater-Deckard, Kirby; Petrill, Stephen A; Thompson, Lee A

    2012-08-01

    Previous research documented a robust link between difficulties in self-regulation and development of externalizing problems (i.e., aggression and delinquency). In this study, we examined the longitudinal additive and interactive genetic and environmental covariation underlying this well-established link using a twin design. The sample included 131 pairs of monozygotic twins and 173 pairs of same-sex dizygotic twins who participated in three waves of annual assessment. Mothers and fathers provided reports of externalizing problems. Teacher report and observer rating were used to assess twin's attention regulation. The etiology underlying the link between externalizing problems and attention regulation shifted from a common genetic mechanism to a common environmental mechanism in the transition across middle childhood. Household chaos moderated the genetic variance of and covariance between externalizing problems and attention regulation. The genetic influence on individual differences in both externalizing problems and attention regulation was stronger in more chaotic households. However, higher levels of household chaos attenuated the genetic link between externalizing problems and attention regulation.

  17. Effects of labor force participation on women's health: new evidence from a longitudinal study.

    PubMed

    Waldron, I; Jacobs, J A

    1988-12-01

    Effects of labor force participation on women's health are evaluated in analyses of longitudinal data for a national sample of older middle-aged women. Our findings indicate that labor force participation had beneficial effects on health for unmarried women and for married black women, but, on the average, labor force participation had no significant effect on health for married white women. Analyses by occupational category suggest that labor force participation had beneficial effects on health for some blue collar married women, but, on the average, labor force participation had harmful effects on health for white collar married women. Our findings, taken together with previous evidence, suggest that employment may increase social support, and job-related social support may have particularly beneficial effects on health for unmarried women and for married women whose husbands are not emotionally supportive confidants. Additional results from this study showed no significant difference in the health effects of part-time and full-time employment.

  18. Computerized Self-Administered Measures of Mood and Appetite for Older Adults: The Novel Assessment of Nutrition and Ageing Toolkit.

    PubMed

    Brown, Laura J E; Adlam, Tim; Hwang, Faustina; Khadra, Hassan; Maclean, Linda M; Rudd, Bridey; Smith, Tom; Timon, Claire; Williams, Elizabeth A; Astell, Arlene J

    2018-02-01

    The "Novel Assessment of Nutrition and Ageing" (NANA) toolkit is a computerized system for collecting longitudinal information about older adults' health and behavior. Here, we describe the validation of six items for measuring older adults' self-reported mood and appetite as part of the NANA system. In Study 1, 48 community-living older adults (aged 65-89 years) completed NANA measures of their current mood and appetite alongside standard paper measures, on three occasions, in a laboratory setting. In Study 2, 40 community-living older adults (aged 64-88 years) completed daily NANA measures of momentary mood and appetite in their own homes, unsupervised, alongside additional measures of health and behavior, over three 7-day periods. The NANA measures were significantly correlated with standard measures of mood and appetite, and showed stability over time. They show utility for tracking mood and appetite longitudinally, and for better understanding links with other aspects of health and behavior.

  19. Externalizing problems, attention regulation, and household chaos: A longitudinal behavioral genetic study

    PubMed Central

    Wang, Zhe; Deater-Deckard, Kirby; Petrill, Stephen A.; Thompson, Lee A.

    2015-01-01

    Previous research has documented a robust link between difficulties in self-regulation and development of externalizing problems (i.e., aggression and delinquency). In the current study, we examined the longitudinal additive and interactive genetic and environmental covariation underlying this well-established link using a twin design. The sample included 131 pairs of monozygotic twins and 173 pairs of same-sex dizygotic twins who participated in three waves of annual assessment. Mothers and fathers provided reports of externalizing problems. Teacher report and observer rating were used to assess twin’s attention regulation. The etiology underlying the link between externalizing problems and attention regulation shifted from a common genetic mechanism to a common environmental mechanism in the transition across middle childhood. Household chaos moderated the genetic variance of and covariance between externalizing problems and attention regulation. The genetic influence on individual differences in both externalizing problems and attention regulation was stronger in more chaotic household. However, higher levels of household chaos attenuated the genetic link between externalizing problems and attention regulation. PMID:22781853

  20. Covariance Partition Priors: A Bayesian Approach to Simultaneous Covariance Estimation for Longitudinal Data.

    PubMed

    Gaskins, J T; Daniels, M J

    2016-01-02

    The estimation of the covariance matrix is a key concern in the analysis of longitudinal data. When data consists of multiple groups, it is often assumed the covariance matrices are either equal across groups or are completely distinct. We seek methodology to allow borrowing of strength across potentially similar groups to improve estimation. To that end, we introduce a covariance partition prior which proposes a partition of the groups at each measurement time. Groups in the same set of the partition share dependence parameters for the distribution of the current measurement given the preceding ones, and the sequence of partitions is modeled as a Markov chain to encourage similar structure at nearby measurement times. This approach additionally encourages a lower-dimensional structure of the covariance matrices by shrinking the parameters of the Cholesky decomposition toward zero. We demonstrate the performance of our model through two simulation studies and the analysis of data from a depression study. This article includes Supplementary Material available online.

  1. On Models for Binomial Data with Random Numbers of Trials

    PubMed Central

    Comulada, W. Scott; Weiss, Robert E.

    2010-01-01

    Summary A binomial outcome is a count s of the number of successes out of the total number of independent trials n = s + f, where f is a count of the failures. The n are random variables not fixed by design in many studies. Joint modeling of (s, f) can provide additional insight into the science and into the probability π of success that cannot be directly incorporated by the logistic regression model. Observations where n = 0 are excluded from the binomial analysis yet may be important to understanding how π is influenced by covariates. Correlation between s and f may exist and be of direct interest. We propose Bayesian multivariate Poisson models for the bivariate response (s, f), correlated through random effects. We extend our models to the analysis of longitudinal and multivariate longitudinal binomial outcomes. Our methodology was motivated by two disparate examples, one from teratology and one from an HIV tertiary intervention study. PMID:17688514

  2. Colorado Longitudinal Twin Study of Reading Disability

    ERIC Educational Resources Information Center

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

    2007-01-01

    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…

  3. 76 FR 65187 - Notice of Proposed Information Collection Requests

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-20

    ... careers. This study includes a new student assessment in algebraic skills, reasoning, and problem solving... School Longitudinal Study of 2009 (HSLS:09) High School Transcript Collection and College Update Field... Longitudinal Study of 2009 (HSLS:09) is a nationally representative, longitudinal study of more than 20,000...

  4. Developmental dyscalculia: a dysconnection syndrome?

    PubMed

    Kucian, Karin; Ashkenazi, Simone Schwizer; Hänggi, Jürgen; Rotzer, Stephanie; Jäncke, Lutz; Martin, Ernst; von Aster, Michael

    2014-09-01

    Numerical understanding is important for everyday life. For children with developmental dyscalculia (DD), numbers and magnitudes present profound problems which are thought to be based upon neuronal impairments of key regions for numerical understanding. The aim of the present study was to investigate possible differences in white matter fibre integrity between children with DD and controls using diffusion tensor imaging. White matter integrity and behavioural measures were evaluated in 15 children with developmental dyscalculia aged around 10 years and 15 matched controls. The main finding, obtained by a whole brain group comparison, revealed reduced fractional anisotropy in the superior longitudinal fasciculus in children with developmental dyscalculia. In addition, a region of interest analysis exhibited prominent deficits in fibres of the superior longitudinal fasciculus adjacent to the intraparietal sulcus, which is thought to be the core region for number processing. To conclude, our results outline deficient fibre projection between parietal, temporal and frontal regions in children with developmental dyscalculia, and therefore raise the question of whether dyscalculia can be seen as a dysconnection syndrome. Since the superior longitudinal fasciculus is involved in the integration and control of distributed brain processes, the present results highlight the importance of considering broader domain-general mechanisms in the diagnosis and therapy of dyscalculia.

  5. Writing abilities longitudinally predict academic outcomes of adolescents with ADHD.

    PubMed

    Molitor, Stephen J; Langberg, Joshua M; Bourchtein, Elizaveta; Eddy, Laura D; Dvorsky, Melissa R; Evans, Steven W

    2016-09-01

    Students with attention-deficit/hyperactivity disorder (ADHD) often experience a host of negative academic outcomes, and deficits in reading and mathematics abilities contribute to these academic impairments. Students with ADHD may also have difficulties with written expression, but there has been minimal research in this area and it is not clear whether written expression abilities uniquely contribute to the academic functioning of students with ADHD. The current study included a sample of 104 middle school students diagnosed with ADHD (Grades 6-8). Participants were followed longitudinally to evaluate whether written expression abilities at baseline predicted student grade point average (GPA) and parent ratings of academic impairment 18 months later, after controlling for reading ability and additional relevant covariates. Written expression abilities longitudinally predicted both academic outcomes above and beyond ADHD and oppositional defiant disorder symptoms, medication use, reading ability, and baseline values of GPA and parent-rated academic impairment. Follow-up analyses revealed that no single aspect of written expression was demonstrably more impactful on academic outcomes than the others, suggesting that writing as an entire process should be the focus of intervention. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  6. A Longitudinal Test of the Demand–Control Model Using Specific Job Demands and Specific Job Control

    PubMed Central

    van Vegchel, Natasja; Shimazu, Akihito; Schaufeli, Wilmar; Dormann, Christian

    2010-01-01

    Background Supportive studies of the demand–control (DC) model were more likely to measure specific demands combined with a corresponding aspect of control. Purpose A longitudinal test of Karasek’s (Adm Sci Q. 24:285–308, 1) job strain hypothesis including specific measures of job demands and job control, and both self-report and objectively recorded well-being. Method Job strain hypothesis was tested among 267 health care employees from a two-wave Dutch panel survey with a 2-year time lag. Results Significant demand/control interactions were found for mental and emotional demands, but not for physical demands. The association between job demands and job satisfaction was positive in case of high job control, whereas this association was negative in case of low job control. In addition, the relation between job demands and psychosomatic health symptoms/sickness absence was negative in case of high job control and positive in case of low control. Conclusion Longitudinal support was found for the core assumption of the DC model with specific measures of job demands and job control as well as self-report and objectively recorded well-being. PMID:20195810

  7. Hypersonic aerodynamic characteristics of an all-body research aircraft configuration

    NASA Technical Reports Server (NTRS)

    Clark, L. E.

    1973-01-01

    An experimental investigation was conducted at Mach 6 to determine the hypersonic aerodynamic characteristics of an all-body, delta-planform, hypersonic research aircraft (HYFAC configuration). The aerodynamic characteristics were obtained at Reynolds numbers based on model length of 2.84 million and 10.5 million and over an angle-of-attack range from minus 4 deg to 20 deg. The experimental results show that the HYFAC configuration is longitudinally stable and can be trimmed over the range of test conditions. The configuration had a small degree of directional stability over the angle-of-attack range and positive effective dihedral at angles of attack greater than 2 deg. Addition of canards caused a decrease in longitudinal stability and an increase in directional stability. Oil-flow studies revealed extensive areas of separated and vortex flow on the fuselage lee surface. A limited comparison of wind-tunnel data with several hypersonic approximations indicated that, except for the directional stability, the tangent-cone method gave adequate agreement at control settings between 5 deg and minus 5 deg and positive lift coefficient. A limited comparison indicated that the HYFAC configuration had greater longitudinal stability than an elliptical-cross-section configuration, but a lower maximum lift-drag ratio.

  8. A longitudinal examination of the influence of maturation on physical self-perceptions and the relationship with physical activity in early adolescent girls.

    PubMed

    Knowles, Ann-Marie; Niven, Ailsa G; Fawkner, Samantha G; Henretty, Joan M

    2009-06-01

    This longitudinal study investigated the influence of maturation on physical self-perceptions and the relationship with physical activity in early adolescent girls (N=150; mean age=12.79+/-0.31). Physical characteristics were measured and participants completed the Physical Activity Questionnaire for Children, the Children and Youth Physical Self-Perception Profile and the Pubertal Development Scale on two occasions 12 months apart. The results demonstrated a decrease in overall physical activity levels over 12 months which was not influenced by maturational status or physical characteristics. Additional analysis indicated that physical self-perceptions partially accounted for the explained variance in physical activity change, with physical condition being an important individual predictor of physical activity. Further analysis indicated that body mass was an important individual predictor of changes in perceptions of body attractiveness and physical self-worth. At this age maturation has a limited influence on the physical activity behaviours of early adolescent girls and although the variance in physical activity was partly accounted for by physical self-perceptions, this was a relatively small contribution and other factors related to this drop in physical activity need to be considered longitudinally.

  9. Do Natural Experiments of Changes in Neighborhood Built Environment Impact Physical Activity and Diet? A Systematic Review

    PubMed Central

    George, Emma S.; Feng, Xiaoqi; Merom, Dafna; Bennie, Andrew; Cook, Amelia; Dwyer, Genevieve; Pang, Bonnie; Astell-Burt, Thomas

    2018-01-01

    Physical activity and diet are major modifiable risk factors for chronic disease and have been shown to be associated with neighborhood built environment. Systematic review evidence from longitudinal studies on the impact of changing the built environment on physical activity and diet is currently lacking. A systematic review of natural experiments of neighborhood built environment was conducted. The aims of this systematic review were to summarize study characteristics, study quality, and impact of changes in neighborhood built environment on physical activity and diet outcomes among residents. Natural experiments of neighborhood built environment change, exploring longitudinal impacts on physical activity and/or diet in residents, were included. From five electronic databases, 2084 references were identified. A narrative synthesis was conducted, considering results in relation to study quality. Nineteen papers, reporting on 15 different exposures met inclusion criteria. Four studies included a comparison group and 11 were pre-post/longitudinal studies without a comparison group. Studies reported on the impact of redeveloping or introducing cycle and/or walking trails (n = 5), rail stops/lines (n = 4), supermarkets and farmers’ markets (n = 4) and park and green space (n = 2). Eight/15 studies reported at least one beneficial change in physical activity, diet or another associated health outcome. Due to limitations in study design and reporting, as well as the wide array of outcome measures reported, drawing conclusions to inform policy was challenging. Future research should consider a consistent approach to measure the same outcomes (e.g., using measurement methods that collect comparable physical activity and diet outcome data), to allow for pooled analyses. Additionally, including comparison groups wherever possible and ensuring high quality reporting is essential. PMID:29373567

  10. Do Natural Experiments of Changes in Neighborhood Built Environment Impact Physical Activity and Diet? A Systematic Review.

    PubMed

    MacMillan, Freya; George, Emma S; Feng, Xiaoqi; Merom, Dafna; Bennie, Andrew; Cook, Amelia; Sanders, Taren; Dwyer, Genevieve; Pang, Bonnie; Guagliano, Justin M; Kolt, Gregory S; Astell-Burt, Thomas

    2018-01-26

    Physical activity and diet are major modifiable risk factors for chronic disease and have been shown to be associated with neighborhood built environment. Systematic review evidence from longitudinal studies on the impact of changing the built environment on physical activity and diet is currently lacking. A systematic review of natural experiments of neighborhood built environment was conducted. The aims of this systematic review were to summarize study characteristics, study quality, and impact of changes in neighborhood built environment on physical activity and diet outcomes among residents. Natural experiments of neighborhood built environment change, exploring longitudinal impacts on physical activity and/or diet in residents, were included. From five electronic databases, 2084 references were identified. A narrative synthesis was conducted, considering results in relation to study quality. Nineteen papers, reporting on 15 different exposures met inclusion criteria. Four studies included a comparison group and 11 were pre-post/longitudinal studies without a comparison group. Studies reported on the impact of redeveloping or introducing cycle and/or walking trails ( n = 5), rail stops/lines ( n = 4), supermarkets and farmers' markets ( n = 4) and park and green space ( n = 2). Eight/15 studies reported at least one beneficial change in physical activity, diet or another associated health outcome. Due to limitations in study design and reporting, as well as the wide array of outcome measures reported, drawing conclusions to inform policy was challenging. Future research should consider a consistent approach to measure the same outcomes (e.g., using measurement methods that collect comparable physical activity and diet outcome data), to allow for pooled analyses. Additionally, including comparison groups wherever possible and ensuring high quality reporting is essential.

  11. Dispelling the myth of "smart drugs": cannabis and alcohol use problems predict nonmedical use of prescription stimulants for studying.

    PubMed

    Arria, Amelia M; Wilcox, Holly C; Caldeira, Kimberly M; Vincent, Kathryn B; Garnier-Dykstra, Laura M; O'Grady, Kevin E

    2013-03-01

    This study tested the hypothesis that college students' substance use problems would predict increases in skipping classes and declining academic performance, and that nonmedical use of prescription stimulants (NPS) for studying would occur in association with this decline. A cohort of 984 students in the College Life Study at a large public university in the US participated in a longitudinal prospective study. Interviewers assessed NPS; Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) cannabis and alcohol use disorders; and frequency of skipping class. Semester grade point average (GPA) was obtained from the university. Control variables were race, sex, family income, high school GPA, and self-reported attention deficit hyperactivity disorder diagnosis. Longitudinal growth curve modeling of four annual data waves estimated the associations among the rates of change of cannabis use disorder, percentage of classes skipped, and semester GPA. The associations between these trajectories and NPS for studying were then evaluated. A second structural model substituted alcohol use disorder for cannabis use disorder. More than one-third (38%) reported NPS for studying at least once by Year 4. Increases in skipping class were associated with both alcohol and cannabis use disorder, which were associated with declining GPA. The hypothesized relationships between these trajectories and NPS for studying were confirmed. These longitudinal findings suggest that escalation of substance use problems during college is related to increases in skipping class and to declining academic performance. NPS for studying is associated with academic difficulties. Although additional research is needed to investigate causal pathways, these results suggest that nonmedical users of prescription stimulants could benefit from a comprehensive drug and alcohol assessment to possibly mitigate future academic declines. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. A Longitudinal Examination of Mothers' Depression and PTSD Symptoms as Impacted by Partner-Abusive Men's Harm to Their Children.

    PubMed

    Rivera, Echo A; Sullivan, Cris M; Zeoli, April M; Bybee, Deborah

    2016-02-12

    Intimate partner violence (IPV) is a serious and widespread form of gender-based violence that disproportionately affects women. It is well established that IPV victimization contributes to depression and posttraumatic stress disorder (PTSD), and that many partner-abusive men continue to perpetuate abuse even after their relationship with the victim ends. In addition, when men harm their partners, they are more likely to harm their children, and evidence suggests that this harm continues post-separation. However, scant research has been conducted on men's harm to their children as an extension of IPV perpetration, with even less known about the mental health impact this form of abuse has on mothers. For this longitudinal cohort study, 40 partner-abused mothers who had separated, or were planning to separate, from an abusive partner with whom they shared children were recruited. Women were interviewed 4 times over 1 year. Results confirmed that, in addition to men's physical abuse perpetration relating to subsequent increases in mothers' depression and PTSD symptoms over time, their harm to the children predicted both mothers' depression and PTSD symptoms as well. © The Author(s) 2016.

  13. Bioimpedance cardiography in pregnancy: A longitudinal cohort study on hemodynamic pattern and outcome.

    PubMed

    Andreas, Martin; Kuessel, Lorenz; Kastl, Stefan P; Wirth, Stefan; Gruber, Kathrin; Rhomberg, Franziska; Gomari-Grisar, Fatemeh A; Franz, Maximilian; Zeisler, Harald; Gottsauner-Wolf, Michael

    2016-06-01

    Pregnancy associated cardiovascular pathologies have a significant impact on outcome for mother and child. Bioimpedance cardiography may provide additional outcome-relevant information early in pregnancy and may also be used as a predictive instrument for pregnancy-associated diseases. We performed a prospective longitudinal cohort trial in an outpatient setting and included 242 pregnant women. Cardiac output and concomitant hemodynamic data were recorded from 11(th)-13(th) week of gestation every 5(th) week as well as at two occasions post partum employing bioimpedance cardiography. Cardiac output increased during pregnancy and peaked early in the third trimester. A higher heart rate and a decreased systemic vascular resistance were accountable for the observed changes. Women who had a pregnancy-associated disease during a previous pregnancy or developed hypertension or preeclampsia had a significantly increased cardiac output early in pregnancy. Furthermore, an effect of cardiac output on birthweight was found in healthy pregnancies and could be confirmed with multiple linear regression analysis. Cardiovascular adaptation during pregnancy is characterized by distinct pattern described herein. These may be altered in women at risk for preeclampsia or reduced birthweigth. The assessment of cardiac parameters by bioimpedance cardiography could be performed at low costs without additional risks.

  14. Planetary wave-like oscillations in the ionosphere retrieved with a longitudinal chain of ionosondes at high northern latitudes

    NASA Astrophysics Data System (ADS)

    Stray, Nora H.; Espy, Patrick J.

    2018-06-01

    This paper examines the influence of neutral dynamics on the high latitude ionosphere. Using a longitudinal chain of ionosondes at high northern latitudes (52°-65° N), planetary wave-like structures were observed in the spatial structure of the peak electron density in the ionosphere. Longitudinal wavenumbers S0, S1 and S2 have been extracted from these variations of the F layer. The observed wave activity in wavenumber one and two does not show any significant correlation with indices of magnetic activity, suggesting that this is not the primary driver. In addition, the motion of the S1 ionospheric wave structures parallels that of the S1 planetary waves observed in the winds of the mesosphere-lower-thermosphere derived from a longitudinal array of SuperDARN meteor-radar wind measurements. The time delay between the motions of the wave structures would indicate a indirect coupling, commensurate with the diffusion to the ionosphere of mesospheric atomic oxygen perturbations.

  15. Aeroelastic Sizing for High-Speed Research (HSR) Longitudinal Control Alternatives Project (LCAP)

    NASA Technical Reports Server (NTRS)

    Walsh, Joanne L.; Dunn, H. J.; Stroud, W. Jefferson; Barthelemy, J.-F.; Weston, Robert P.; Martin, Carl J.; Bennett, Robert M.

    2005-01-01

    The Longitudinal Control Alternatives Project (LCAP) compared three high-speed civil transport configurations to determine potential advantages of the three associated longitudinal control concepts. The three aircraft configurations included a conventional configuration with a layout having a horizontal aft tail, a configuration with a forward canard in addition to a horizontal aft tail, and a configuration with only a forward canard. The three configurations were aeroelastically sized and were compared on the basis of operational empty weight (OEW) and longitudinal control characteristics. The sized structure consisted of composite honeycomb sandwich panels on both the wing and the fuselage. Design variables were the core depth of the sandwich and the thicknesses of the composite material which made up the face sheets of the sandwich. Each configuration was sized for minimum structural weight under linear and nonlinear aeroelastic loads subject to strain, buckling, ply-mixture, and subsonic and supersonic flutter constraints. This report describes the methods that were used and the results that were generated for the aeroelastic sizing of the three configurations.

  16. Longitudinal magnet forces?

    NASA Astrophysics Data System (ADS)

    Graneau, P.

    1984-03-01

    The Ampere electrodynamics of metallic conductors and experiments supporting it predict that the interaction of a current-carrying wire with its own magnetic field should produce longitudinal mechanical forces in the conductor, existing in addition to the transverse Lorentz forces. The longitudinal forces should stretch the conductor and have been referred to as Ampere tension. In 1964 it was discovered that a current pulse would break a straight copper wire into many fragments without visible melting. A metallurgical examination of the pieces confirmed that the metal parted in the solid state. The same observation has now been made with aluminum wires. In the latest experiments the wire was bent into a semicircle and arc-connected to a capacitor discharge circuit. The arc connections ruled out rupture by Lorentz hoop tension and indicated the longitudinal forces may also arise in circular magnet windings. Explanations of wire fragmentation by thermal shock, longitudinal stress waves, Lorentz pinch-off, bending stresses, and material defects have been considered and found unconvincing. Computed Ampere tensions would be sufficient to fracture hot wires. The Ampere tension would double the hoop tension normally expected in dipole magnets. This should be borne in mind in the design of large dipole magnets contemplated for MHD power generators and railgun accelerators.

  17. Longitudinal study of factors affecting taste sense decline in old-old individuals.

    PubMed

    Ogawa, T; Uota, M; Ikebe, K; Arai, Y; Kamide, K; Gondo, Y; Masui, Y; Ishizaki, T; Inomata, C; Takeshita, H; Mihara, Y; Hatta, K; Maeda, Y

    2017-01-01

    The sense of taste plays a pivotal role for personal assessment of the nutritional value, safety and quality of foods. Although it is commonly recognised that taste sensitivity decreases with age, alterations in that sensitivity over time in an old-old population have not been previously reported. Furthermore, no known studies utilised comprehensive variables regarding taste changes and related factors for assessments. Here, we report novel findings from a 3-year longitudinal study model aimed to elucidate taste sensitivity decline and its related factors in old-old individuals. We utilised 621 subjects aged 79-81 years who participated in the Septuagenarians, Octogenarians, Nonagenarians Investigation with Centenarians Study for baseline assessments performed in 2011 and 2012, and then conducted follow-up assessments 3 years later in 328 of those. Assessment of general health, an oral examination and determination of taste sensitivity were performed for each. We also evaluated cognitive function using Montreal Cognitive Assessment findings, then excluded from analysis those with a score lower than 20 in order to secure the validity and reliability of the subjects' answers. Contributing variables were selected using univariate analysis, then analysed with multivariate logistic regression analysis. We found that males showed significantly greater declines in taste sensitivity for sweet and sour tastes than females. Additionally, subjects with lower cognitive scores showed a significantly greater taste decrease for salty in multivariate analysis. In conclusion, our longitudinal study revealed that gender and cognitive status are major factors affecting taste sensitivity in geriatric individuals. © 2016 John Wiley & Sons Ltd.

  18. Risk factors of Internet addiction and the health effect of internet addiction on adolescents: a systematic review of longitudinal and prospective studies.

    PubMed

    Lam, Lawrence T

    2014-11-01

    Internet gaming addiction was included in the latest version of the DSM-V as a possible disorder recently, while debate is still on-going as to whether the condition called "Internet Addiction" (IA) could be fully recognised as an established disorder. The major contention is how well IA could fulfil the validation criteria as a psychiatric disorder as in other well-established behavioural addictions. In addition to various proposed validation criteria, evidence of risk and protective factors as well as development of outcomes from longitudinal and prospective studies are suggested as important. A systematic review of available longitudinal and prospective studies was conducted to gather epidemiological evidence on risk and protective factors of IA and the health effect of IA on adolescents. Nine articles were identified after an extensive search of the literature in accordance to the PRISMA guidelines. Of these, eight provided data on risk or protective factors of IA and one focused solely on the effects of IA on mental health. Information was extracted and analysed systematically from each study and tabulated. Many exposure variables were studied and could be broadly classified into three main categories: psychopathologies of the participants, family and parenting factors, and others such as Internet usage, motivation, and academic performance. Some were found to be potential risk or protective factors of IA. It was also found that exposure to IA had a detrimental effect on the mental health of young people. These results were discussed in light of their implications to the fulfilment of the validation criteria.

  19. A prospective longitudinal study of seasonality in African students living in the greater Washington, D.C. metropolitan area.

    PubMed

    Guzman, Alvaro; Zebrak, Ryszard; Rohan, Kelly J; Sumar, Irshad A; Savchenko, Svetlana; Stiller, John W; Valadez-Meltzer, Adela; Olsen, Cara; Lapidus, Manana; Soriano, Joseph J; Postolache, Teodor T

    2007-05-01

    We conducted a prospective, longitudinal study of seasonality in a vulnerable population, i.e., African students who migrated to a temperate climate. Consistent with previous cross-sectional studies, we hypothesized lower mood and energy, and higher appetite and weight, in fall/winter than in spring/summer. Four cohorts of African students attending a year-long nursing school program without vacation in Washington, D.C., were assessed monthly for 1 year. Forty-three subjects (mean age = 33.46 +/- 6.25), consisting of predominantly females (76.7%), completed the study. The cohorts began their academic program in different seasons (one each in winter, spring, summer, and fall), inherently minimizing confounding influences on seasonality, such as academic and immigration stress, as well as allowing adjustment for an order effect. At each assessment, students completed three 100-mm visual analog scales for mood, energy, and appetite, and were weighed on a digital scale. For each standardized dependent variable, a repeated measure ANOVA was used and, if a significant effect of month was identified, averages for spring/summer and fall/winter were compared using paired t-tests. In addition, a mixed model for repeated measures was applied to raw (nonstandardized) data. Body weight was significantly higher in fall/winter than in spring/summer (p < 0.01). No seasonal differences in mood, energy, or appetite were found. Benefiting from certain unique features of our cohorts allowing adjustment for order effects, this is the first study to identify a seasonal variation in body weight with a peak in winter using longitudinal monthly measurements.

  20. Predictors of child-to-parent aggression: A 3-year longitudinal study.

    PubMed

    Calvete, Esther; Orue, Izaskun; Gamez-Guadix, Manuel; Bushman, Brad J

    2015-05-01

    Although we rarely hear about it, children sometimes aggress against their parents. This is a difficult topic to study because abused parents and abusive children are both reluctant to admit the occurrence of child-to-parent aggression. There are very few research studies on this topic, and even fewer theoretical explanations of why it occurs. We predicted that exposure to violence in the home (e.g., parents aggressing against each other) and ineffective parenting (i.e., parenting that is overly permissive or lacks warmth) influences cognitive schemas of how children perceive themselves and the world around them (i.e., whether aggression is normal, whether they develop grandiose self-views, and whether they feel disconnected and rejected), which, in turn, predicts child-to-parent aggression. In a 3-year longitudinal study of 591 adolescents and their parents, we found that exposure to violence in Year 1 predicted child-to-parent aggression in Year 3. In addition, parenting characterized by lack of warmth in Year 1 was related to narcissistic and entitled self-views and disconnection and rejection schemas in Year 2, which, in turn, predicted child-to-mother and child-to-father aggression in Year 3. Gender comparisons indicated that narcissism predicted child-to-parent aggression only in boys and that exposure to violence was a stronger predictor of child-to-father violence in boys. This longitudinal study increases our understanding of the understudied but important topic of child-to-parent aggression, and will hopefully stimulate future research. (c) 2015 APA, all rights reserved).

  1. A Longitudinal Study of Adolescent Adjustment Following Family Transitions

    ERIC Educational Resources Information Center

    Ruschena, Eda; Prior, Margot; Sanson, Ann; Smart, Diana

    2005-01-01

    Background: This study examined the impact of family transitions, that is, parental separation, divorce, remarriage and death, upon the lives of Australian children and adolescents in a longitudinal study of temperament and development. Methods: Using longitudinal and concurrent questionnaire data, outcomes for young people experiencing…

  2. Physical activity and asthma: A longitudinal and multi-country study.

    PubMed

    Russell, Melissa A; Janson, Christer; Real, Francisco Gómez; Johannessen, Ane; Waatevik, Marie; Benediktsdóttir, Bryndis; Holm, Mathias; Lindberg, Eva; Schlünssen, Vivi; Raza, Wasif; Dharmage, Shyamali C; Svanes, Cecilie

    2017-11-01

    To investigate the impact of physical activity on asthma in middle-aged adults, in one longitudinal analysis, and one multi-centre cross-sectional analysis. The Respiratory Health in Northern Europe (RHINE) is a population-based postal questionnaire cohort study. Physical activity, height and weight were self-reported in Bergen, Norway, at RHINE II (1999-2001) and all centres at RHINE III (2010-2012). A longitudinal analysis of Bergen data investigated the association of baseline physical activity with follow-up asthma, incident asthma and symptoms, using logistic and zero-inflated Poisson regression (n = 1782). A cross-sectional analysis of all RHINE III centres investigated the association of physical activity with concurrent asthma and symptoms (n = 13,542) using mixed-effects models. Body mass index (BMI) was categorised (<20, 20-24.99, 25-29.99, 30+ kg/m 2 ) and physical activity grouped by amount and frequency of lighter (no sweating/heavy breathing) and vigorous (sweating/heavy breathing) activity. In the Bergen longitudinal analysis, undertaking light activity 3+ times/week at baseline was associated with less follow-up asthma (odds ratio [OR] 0.44, 95% confidence interval [CI] 0.22, 0.89), whilst an effect from undertaking vigorous activity 3+ times/week was not detected (OR 1.22, 95% CI 0.44, 2.76). The associations were attenuated with BMI adjustment. In the all-centre cross-sectional analysis an interaction was found, with the association between physical activity and asthma varying across BMI categories. These findings suggest potential longer-term benefit from lighter physical activity, whilst improvement in asthma outcomes from increasing activity intensity was not evident. Additionally, it appears the benefit from physical activity may differ according to BMI.

  3. Annual longitudinal survey at up to five time points reveals reciprocal effects of bedtime delay and depression/anxiety in adolescents.

    PubMed

    Tochigi, Mamoru; Usami, Satoshi; Matamura, Misato; Kitagawa, Yuko; Fukushima, Masako; Yonehara, Hiromi; Togo, Fumiharu; Nishida, Atsushi; Sasaki, Tsukasa

    2016-01-01

    To investigate the longitudinal relationship between sleep habits and mental health in adolescents. Multipoint observation data of up to five years were employed from a prospective cohort study of sleep habits and mental health status conducted from 2009 to 2013 in a unified junior and senior high school (grades 7-12) in Tokyo, Japan. A total of 1078 students answered a self-report questionnaire, including items on usual bed and wake-up times on school days, and the Japanese version of the 12-item General Health Questionnaire (GHQ-12). Latent growth model (LGM) analysis, which requires three or more time point data, showed that longitudinal changes in bedtime and GHQ-12 score (or score for depression/anxiety) were significantly and moderately correlated (correlation coefficient = 0.510, p < 0.05). Another result of interest was that, using an autoregressive cross-lagged (ARCL) model, bedtime and the depression/anxiety score had reciprocal effects the following year: ie, bedtime significantly affects the following year's depression/anxiety, and vice versa. In addition, the analysis provided estimates of mutually predicted changes: one-hour bedtime delay may worsen the GHQ-12 score by 0.2 points, and one-point worsening of the score may delay bedtime by 2.2 minutes. By using up to five multiple time point data, the present study confirms the correlational and reciprocally longitudinal relationship between bedtime delay and mental health status in Japanese adolescents. The results indicate that preventing late bedtime may have a significant effect on improving mental health in adolescents. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Spontaneous myometrial contractility in cows suffering from endometritis-Influence of localisation, smooth muscle layer and cycle phase. An in vitro study.

    PubMed

    Hirsbrunner, Gaby; Kaufmann, Ch; Keller, Ch; Hüsler, J; Steiner, A

    2010-04-01

    Contractility of the healthy bovine myometrium depends on the reproductive state. Furthermore, contractility is influenced by localisation and the direction of smooth muscle strips. However, little is known about the contractile behaviour of the uterus when affected by endometritis. In our study, myometrial specimens from the larger horn (near the corpus and near the tip) in cows suffering from endometritis in estrus (n=8) or diestrus (n=8) were collected after slaughter. Two strips were prepared from each region corresponding to the circular and the longitudinal muscle layers, respectively. The spontaneous contractility of these strips was recorded in an organ bath. To analyse the results, the 2.5h recordings were divided into five periods of 30 min each. The variables area under curve (AUC) and maximal (A(max)) and minimal amplitude (A(min)) were calculated separately for each period, and the results were analysed using a non-parametric model regarding the influence of cycle phase (estrus vs. diestrus), region (corpus vs. tip) and muscle layer (circular vs. longitudinal). The values of both AUC and A(max) increased significantly over time. Muscle layer had a significant effect on AUC (corpus, tip) and A(max) (tip): the values of circular layers were increased compared to longitudinal layers. Dividing the data into subgroups allowed us to analyse them additionally according to muscle layer: In longitudinal layers, A(max) was increased at the corpus as compared with the tip. In this model, the factor cycle phase did not produce any significant difference in spontaneous myometrial activity. However, data of all variables showed non-significant higher values in estrus than in diestrus samples. Copyright 2009 Elsevier B.V. All rights reserved.

  5. Fractional Brownian motion and multivariate-t models for longitudinal biomedical data, with application to CD4 counts in HIV-positive patients.

    PubMed

    Stirrup, Oliver T; Babiker, Abdel G; Carpenter, James R; Copas, Andrew J

    2016-04-30

    Longitudinal data are widely analysed using linear mixed models, with 'random slopes' models particularly common. However, when modelling, for example, longitudinal pre-treatment CD4 cell counts in HIV-positive patients, the incorporation of non-stationary stochastic processes such as Brownian motion has been shown to lead to a more biologically plausible model and a substantial improvement in model fit. In this article, we propose two further extensions. Firstly, we propose the addition of a fractional Brownian motion component, and secondly, we generalise the model to follow a multivariate-t distribution. These extensions are biologically plausible, and each demonstrated substantially improved fit on application to example data from the Concerted Action on SeroConversion to AIDS and Death in Europe study. We also propose novel procedures for residual diagnostic plots that allow such models to be assessed. Cohorts of patients were simulated from the previously reported and newly developed models in order to evaluate differences in predictions made for the timing of treatment initiation under different clinical management strategies. A further simulation study was performed to demonstrate the substantial biases in parameter estimates of the mean slope of CD4 decline with time that can occur when random slopes models are applied in the presence of censoring because of treatment initiation, with the degree of bias found to depend strongly on the treatment initiation rule applied. Our findings indicate that researchers should consider more complex and flexible models for the analysis of longitudinal biomarker data, particularly when there are substantial missing data, and that the parameter estimates from random slopes models must be interpreted with caution. © 2015 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

  6. Micro-CT Based Experimental Liver Imaging Using a Nanoparticulate Contrast Agent: A Longitudinal Study in Mice

    PubMed Central

    Boll, Hanne; Nittka, Stefanie; Doyon, Fabian; Neumaier, Michael; Marx, Alexander; Kramer, Martin; Groden, Christoph; Brockmann, Marc A.

    2011-01-01

    Background Micro-CT imaging of liver disease in mice relies on high soft tissue contrast to detect small lesions like liver metastases. Purpose of this study was to characterize the localization and time course of contrast enhancement of a nanoparticular alkaline earth metal-based contrast agent (VISCOVER ExiTron nano) developed for small animal liver CT imaging. Methodology ExiTron nano 6000 and ExiTron nano 12000, formulated for liver/spleen imaging and angiography, respectively, were intravenously injected in C57BL/6J-mice. The distribution and time course of contrast enhancement were analysed by repeated micro-CT up to 6 months. Finally, mice developing liver metastases after intrasplenic injection of colon carcinoma cells underwent longitudinal micro-CT imaging after a single injection of ExiTron nano. Principal Findings After a single injection of ExiTron nano the contrast of liver and spleen peaked after 4–8 hours, lasted up to several months and was tolerated well by all mice. In addition, strong contrast enhancement of abdominal and mediastinal lymph nodes and the adrenal glands was observed. Within the first two hours after injection, particularly ExiTron nano 12000 provided pronounced contrast for imaging of vascular structures. ExiTron nano facilitated detection of liver metastases and provided sufficient contrast for longitudinal observation of tumor development over weeks. Conclusions The nanoparticulate contrast agents ExiTron nano 6000 and 12000 provide strong contrast of the liver, spleen, lymph nodes and adrenal glands up to weeks, hereby allowing longitudinal monitoring of pathological processes of these organs in small animals, with ExiTron nano 12000 being particularly optimized for angiography due to its very high initial vessel contrast. PMID:21984939

  7. Nuclear magnetic relaxation by the dipolar EMOR mechanism: Three-spin systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chang, Zhiwei; Halle, Bertil, E-mail: bertil.halle@bpc.lu.se

    2016-07-21

    In aqueous systems with immobilized macromolecules, including biological tissue, the longitudinal spin relaxation of water protons is primarily induced by exchange-mediated orientational randomization (EMOR) of intra- and intermolecular magnetic dipole-dipole couplings. Starting from the stochastic Liouville equation, we have developed a non-perturbative theory that can describe relaxation by the dipolar EMOR mechanism over the full range of exchange rates, dipole couplings, and Larmor frequencies. Here, we implement the general dipolar EMOR theory for a macromolecule-bound three-spin system, where one, two, or all three spins exchange with the bulk solution phase. In contrast to the previously studied two-spin system with amore » single dipole coupling, there are now three dipole couplings, so relaxation is affected by distinct correlations as well as by self-correlations. Moreover, relaxation can now couple the magnetizations with three-spin modes and, in the presence of a static dipole coupling, with two-spin modes. As a result of this complexity, three secondary dispersion steps with different physical origins can appear in the longitudinal relaxation dispersion profile, in addition to the primary dispersion step at the Larmor frequency matching the exchange rate. Furthermore, and in contrast to the two-spin system, longitudinal relaxation can be significantly affected by chemical shifts and by the odd-valued (“imaginary”) part of the spectral density function. We anticipate that the detailed studies of two-spin and three-spin systems that have now been completed will provide the foundation for developing an approximate multi-spin dipolar EMOR theory sufficiently accurate and computationally efficient to allow quantitative molecular-level interpretation of frequency-dependent water-proton longitudinal relaxation data from biophysical model systems and soft biological tissue.« less

  8. Longitudinal development of number line estimation and mathematics performance in primary school children.

    PubMed

    Friso-van den Bos, Ilona; Kroesbergen, Evelyn H; Van Luit, Johannes E H; Xenidou-Dervou, Iro; Jonkman, Lisa M; Van der Schoot, Menno; Van Lieshout, Ernest C D M

    2015-06-01

    Children's ability to relate number to a continuous quantity abstraction visualized as a number line is widely accepted to be predictive of mathematics achievement. However, a debate has emerged with respect to how children's placements are distributed on this number line across development. In the current study, different models were applied to children's longitudinal number placement data to get more insight into the development of number line representations in kindergarten and early primary school years. In addition, longitudinal developmental relations between number line placements and mathematical achievement, measured with a national test of mathematics, were investigated using cross-lagged panel modeling. A group of 442 children participated in a 3-year longitudinal study (ages 5-8 years) in which they completed a number-to-position task every 6 months. Individual number line placements were fitted to various models, of which a one-anchor power model provided the best fit for many of the placements at a younger age (5 or 6 years) and a two-anchor power model provided better fit for many of the children at an older age (7 or 8 years). The number of children who made linear placements also grew with age. Cross-lagged panel analyses indicated that the best fit was provided with a model in which number line acuity and mathematics performance were mutually predictive of each other rather than models in which one ability predicted the other in a non-reciprocal way. This indicates that number line acuity should not be seen as a predictor of math but that both skills influence each other during the developmental process. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  9. 77 FR 51788 - Notice of Submission for OMB Review; Institute of Education Sciences; Education Longitudinal...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-27

    ...; Education Longitudinal Study 2002 (ELS:2002) Third Follow-Up Postsecondary Transcripts (ELS:2002 PETS) and Financial Aid Feasibility Study (ELS:2002 FAFS) SUMMARY: The Education Longitudinal Study of 2002 (ELS:2002) is a nationally representative study of two high school grade cohorts (spring 2002 tenth-graders and...

  10. The Impact of Mixing Modes on Reliability in Longitudinal Studies

    ERIC Educational Resources Information Center

    Cernat, Alexandru

    2015-01-01

    Mixed-mode designs are increasingly important in surveys, and large longitudinal studies are progressively moving to or considering such a design. In this context, our knowledge regarding the impact of mixing modes on data quality indicators in longitudinal studies is sparse. This study tries to ameliorate this situation by taking advantage of a…

  11. Integrating Prospective Longitudinal Data: Modeling Personality and Health in the Terman Life Cycle and Hawaii Longitudinal Studies

    ERIC Educational Resources Information Center

    Kern, Margaret L.; Hampson, Sarah E.; Goldberg, Lewis R.; Friedman, Howard S.

    2014-01-01

    The present study used a collaborative framework to integrate 2 long-term prospective studies: the Terman Life Cycle Study and the Hawaii Personality and Health Longitudinal Study. Within a 5-factor personality-trait framework, teacher assessments of child personality were rationally and empirically aligned to establish similar factor structures…

  12. The Coordination and Activity Tracking in CHildren (CATCH) study: rationale and design.

    PubMed

    Cairney, John; Missiuna, Cheryl; Timmons, Brian W; Rodriguez, Christine; Veldhuizen, Scott; King-Dowling, Sara; Wellman, Sarah; Le, Tuyen

    2015-12-21

    Past studies have found that children with Developmental Coordination Disorder (DCD) engage in less physical activity than typically developing children. This "activity deficit" may result in children with DCD being less physically fit and more likely to be overweight or obese, potentially increasing later risk for poor cardiovascular health. Unfortunately, the majority of DCD research has been limited to cross-sectional designs, leading to questions about the complex relationship among motor ability, inactivity and health-related fitness. Of the few longitudinal studies on the topic, determining precedence amongst these factors is difficult because study cohorts typically focus on mid to late childhood. By this age, both decreased physical fitness and obesity are often established. The Coordination and Activity Tracking in CHildren (CATCH) study will examine the pathways connecting DCD, physical activity, physical fitness, and body composition from early to middle childhood. The CATCH study is a prospective cohort study. We aim to recruit a cohort of 600 children aged 4 to 5 years (300 probable DCD [pDCD] and 300 controls) and test them once a year for 4 years. At Phase 1 of baseline testing, we assess motor skills, cognitive ability (IQ), basic anthropometry, flexibility and lower body muscle strength, while parents complete an interview and questionnaires regarding family demographics, their child's physical activity, and behavioural characteristics. Children who move on to Phase 2 (longitudinal cohort) have their body fat percentage, foot structure, aerobic and anaerobic fitness assessed. An accelerometer to measure physical activity is then given to the child and interested family members. The family also receives an accelerometer logbook and 3-day food dairy. At years 2 to 4, children in the longitudinal cohort will have all baseline assessments repeated (excluding the IQ test), and complete an additional measure of perceived self-efficacy. Parents will complete an ADHD index twice within the follow-up period. To assess the association between DCD, fitness and adiposity, our primary analysis will involve longitudinal growth models with fixed effects. The CATCH study will provide a clearer understanding of pathways between DCD and health-related fitness necessary to determine the types of interventions children with DCD require.

  13. Comparing meta-analysis and ecological-longitudinal analysis in time-series studies. A case study of the effects of air pollution on mortality in three Spanish cities

    PubMed Central

    Saez, M; Figueiras, A; Ballester, F; Perez-Hoyos, S; Ocana, R; Tobias, A

    2001-01-01

    STUDY OBJECTIVE—The objective of this paper is to introduce a different approach, called the ecological-longitudinal, to carrying out pooled analysis in time series ecological studies. Because it gives a larger number of data points and, hence, increases the statistical power of the analysis, this approach, unlike conventional ones, allows the complementation of aspects such as accommodation of random effect models, of lags, of interaction between pollutants and between pollutants and meteorological variables, that are hardly implemented in conventional approaches.
DESIGN—The approach is illustrated by providing quantitative estimates of the short-term effects of air pollution on mortality in three Spanish cities, Barcelona, Valencia and Vigo, for the period 1992-1994. Because the dependent variable was a count, a Poisson generalised linear model was first specified. Several modelling issues are worth mentioning. Firstly, because the relations between mortality and explanatory variables were non-linear, cubic splines were used for covariate control, leading to a generalised additive model, GAM. Secondly, the effects of the predictors on the response were allowed to occur with some lag. Thirdly, the residual autocorrelation, because of imperfect control, was controlled for by means of an autoregressive Poisson GAM. Finally, the longitudinal design demanded the consideration of the existence of individual heterogeneity, requiring the consideration of mixed models.
MAIN RESULTS—The estimates of the relative risks obtained from the individual analyses varied across cities, particularly those associated with sulphur dioxide. The highest relative risks corresponded to black smoke in Valencia. These estimates were higher than those obtained from the ecological-longitudinal analysis. Relative risks estimated from this latter analysis were practically identical across cities, 1.00638 (95% confidence intervals 1.0002, 1.0011) for a black smoke increase of 10 µg/m3 and 1.00415 (95% CI 1.0001, 1.0007) for a increase of 10 µg/m3 of sulphur dioxide. Because the statistical power is higher than in the individual analysis more interactions were statistically significant, especially those among air pollutants and meteorological variables.
CONCLUSIONS—Air pollutant levels were related to mortality in the three cities of the study, Barcelona, Valencia and Vigo. These results were consistent with similar studies in other cities, with other multicentric studies and coherent with both, previous individual, for each city, and multicentric studies for all three cities.


Keywords: air pollution; mortality; longitudinal studies PMID:11351001

  14. Alterations of neocortico-limbic association fibers and correlation with diet in prediabetes diagnosed by impaired fasting glucose.

    PubMed

    Hou, Yi-Cheng; Yang, Shwu-Huey; Wu, Yu-Te; Lai, Chien-Han

    2016-06-01

    To assess the existence of alterations in the micro-integrity of the fasciculus in prediabetic subjects. The issue of micro-integrity in white matter tracts has not been adequately addressed in prediabetes. Sixty-four prediabetic subjects and 54 controls were enrolled. All participants completed 24-hour diet records and 3-day diet records and received diffusion tensor imaging at 3T. The data for white matter micro-integrity were analyzed and compared between prediabetic subjects and controls with age and gender as covariates. In addition, voxel-wise regression between white matter micro-integrity, diet, and preprandial glucose levels were used to explore the relationship between white matter micro-integrity and diet or serum glucose levels. We found that prediabetic subjects had significant reductions in the micro-integrity of bilateral anterior thalamic radiation, left inferior longitudinal fasciculus, and left superior longitudinal fasciculus (corrected P < 0.05). In addition, total carbohydrate intake amount and preprandial serum glucose levels were negatively correlated with the micro-integrity in the left inferior longitudinal fasciculus and left anterior thalamic radiation (r: -0.47, corrected P < 0.05). Restrictive alterations in the white matter micro-integrity of the anterior thalamic radiation and inferior and superior longitudinal fasciculi might represent the initial "hot spots" for white matter tract alterations, which might play a role in the development of prediabetes. J. Magn. Reson. Imaging 2016;43:1500-1506. © 2016 Wiley Periodicals, Inc.

  15. Stress predicts brain changes in children: a pilot longitudinal study on youth stress, posttraumatic stress disorder, and the hippocampus.

    PubMed

    Carrion, Victor G; Weems, Carl F; Reiss, Allan L

    2007-03-01

    Does stress damage the brain? Studies of adults with posttraumatic stress disorder have demonstrated smaller hippocampal volumes when compared with the volumes of adults with no posttraumatic stress disorder. Studies of children with posttraumatic stress disorder have not replicated the smaller hippocampal findings in adults, which suggests that smaller hippocampal volume may be caused by neurodevelopmental experiences with stress. Animal research has demonstrated that the glucocorticoids secreted during stress can be neurotoxic to the hippocampus, but this has not been empirically demonstrated in human samples. We hypothesized that cortisol volumes would predict hippocampal volume reduction in patients with posttraumatic symptoms. We report data from a pilot longitudinal study of children (n = 15) with history of maltreatment who underwent clinical evaluation for posttraumatic stress disorder, cortisol, and neuroimaging. Posttraumatic stress disorder symptoms and cortisol at baseline predicted hippocampal reduction over an ensuing 12- to 18-month interval. Results from this pilot study suggest that stress is associated with hippocampal reduction in children with posttraumatic stress disorder symptoms and provide preliminary human evidence that stress may indeed damage the hippocampus. Additional studies seem to be warranted.

  16. Numerical evaluation of longitudinal motions of Wigley hulls advancing in waves by using Bessho form translating-pulsating source Green'S function

    NASA Astrophysics Data System (ADS)

    Xiao, Wenbin; Dong, Wencai

    2016-06-01

    In the framework of 3D potential flow theory, Bessho form translating-pulsating source Green's function in frequency domain is chosen as the integral kernel in this study and hybrid source-and-dipole distribution model of the boundary element method is applied to directly solve the velocity potential for advancing ship in regular waves. Numerical characteristics of the Green function show that the contribution of local-flow components to velocity potential is concentrated at the nearby source point area and the wave component dominates the magnitude of velocity potential in the far field. Two kinds of mathematical models, with or without local-flow components taken into account, are adopted to numerically calculate the longitudinal motions of Wigley hulls, which demonstrates the applicability of translating-pulsating source Green's function method for various ship forms. In addition, the mesh analysis of discrete surface is carried out from the perspective of ship-form characteristics. The study shows that the longitudinal motion results by the simplified model are somewhat greater than the experimental data in the resonant zone, and the model can be used as an effective tool to predict ship seakeeping properties. However, translating-pulsating source Green function method is only appropriate for the qualitative analysis of motion response in waves if the ship geometrical shape fails to satisfy the slender-body assumption.

  17. Early risk and protective factors for problem gambling: A systematic review and meta-analysis of longitudinal studies.

    PubMed

    Dowling, N A; Merkouris, S S; Greenwood, C J; Oldenhof, E; Toumbourou, J W; Youssef, G J

    2017-02-01

    This systematic review aimed to identify early risk and protective factors (in childhood, adolescence or young adulthood) longitudinally associated with the subsequent development of gambling problems. A systematic search of peer-reviewed and grey literature from 1990 to 2015 identified 15 studies published in 23 articles. Meta-analyses quantified the effect size of 13 individual risk factors (alcohol use frequency, antisocial behaviours, depression, male gender, cannabis use, illicit drug use, impulsivity, number of gambling activities, problem gambling severity, sensation seeking, tobacco use, violence, undercontrolled temperament), one relationship risk factor (peer antisocial behaviours), one community risk factor (poor academic performance), one individual protective factor (socio-economic status) and two relationship protective factors (parent supervision, social problems). Effect sizes were on average small to medium and sensitivity analyses revealed that the results were generally robust to the quality of methodological approaches of the included articles. These findings highlight the need for global prevention efforts that reduce risk factors and screen young people with high-risk profiles. There is insufficient investigation of protective factors to adequately guide prevention initiatives. Future longitudinal research is required to identify additional risk and protective factors associated with problem gambling, particularly within the relationship, community, and societal levels of the socio-ecological model. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  18. Adverse Childhood Experiences and Alcohol Consumption in Midlife and Early Old-Age

    PubMed Central

    Leung, Jessica Pui Kei; Britton, Annie; Bell, Steven

    2016-01-01

    Aims To examine the individual and cumulative effects of adverse childhood experiences (ACEs) on alcohol consumption in midlife and early old-age, and the role of ACEs in 10-year drinking trajectories across midlife. Methods Data were from the Whitehall II study, a longitudinal British civil service-based cohort study (N = 7870, 69.5% male). Multinomial logistic regression was used to examine the individual and cumulative effects of ACEs on weekly alcohol consumption. Mixed-effect multilevel modelling was used to explore the relationship between ACEs and change in alcohol consumption longitudinally. Results Participants who were exposed to parental arguments/fights in childhood were 1.24 (95% CI 1.06, 1.45) times more likely to drink at hazardous levels in midlife (mean age 56 years) after controlling for covariates and other ACEs. For each additional exposure to an ACE, the risk of hazardous drinking versus moderate drinking was increased by 1.12 (95% CI 1.03, 1.21) after adjusting for sex, age, adult socio-economic status, ethnicity and marital status. No associations between ACEs and increased risk of hazardous drinking in early old-age (mean age 66 years) were found. In longitudinal analyses, ACEs did not significantly influence 10-year drinking trajectories across midlife. Conclusion The effect of exposure to parental arguments on hazardous drinking persists into midlife. PMID:26553290

  19. Sexist games=sexist gamers? A longitudinal study on the relationship between video game use and sexist attitudes.

    PubMed

    Breuer, Johannes; Kowert, Rachel; Festl, Ruth; Quandt, Thorsten

    2015-04-01

    From the oversexualized characters in fighting games, such as Dead or Alive or Ninja Gaiden, to the overuse of the damsel in distress trope in popular titles, such as the Super Mario series, the under- and misrepresentation of females in video games has been well documented in several content analyses. Cultivation theory suggests that long-term exposure to media content can affect perceptions of social realities in a way that they become more similar to the representations in the media and, in turn, impact one's beliefs and attitudes. Previous studies on video games and cultivation have often been cross-sectional or experimental, and the limited longitudinal work in this area has only considered time intervals of up to 1 month. Additionally, previous work in this area has focused on the effects of violent content and relied on self-selected or convenience samples composed mostly of adolescents or college students. Enlisting a 3 year longitudinal design, the present study assessed the relationship between video game use and sexist attitudes, using data from a representative sample of German players aged 14 and older (N=824). Controlling for age and education, it was found that sexist attitudes--measured with a brief scale assessing beliefs about gender roles in society--were not related to the amount of daily video game use or preference for specific genres for both female and male players. Implications for research on sexism in video games and cultivation effects of video games in general are discussed.

  20. The benefits of personal strengths in mental health of stressed students: A longitudinal investigation.

    PubMed

    Duan, Wenjie

    2016-11-01

    This study used a two-wave longitudinal research design to explore the role of individual strengths, including interpersonal strength, intellectual strength, and temperance strength, in affecting the mental health of stressed college students. A total of 404 stressed Chinese college students were screened to participate in this 12-month longitudinal study. At the beginning of the study (Time 1), students who had not experienced stressful events within the last 12 months were invited to assess their strengths, psychological well-being, and psychological symptoms. After 12 months (Time 2), 404 students who reported stressful experiences completed the scales again and were retained for the final analyses. Academics-related stressors were the most endorsed life events among college students, whose states of mental health showed downward trends from Time 1 to Time 2. Three strengths had weak to modest correlations to mental health at both Time 1 and Time 2. Although the additional variances of mental health explained by the three strengths were very modest, the mediational roles of the strengths were identified. The perceived stress completely mediated the relationship between the strengths and the psychological symptoms and partly mediated the relationship between the strengths and psychological well-being. Individual strengths may function as a defense against perceived stress and are protective factors of mental health. These strengths maintain mental health by enhancing the psychological well-being and reducing the psychological symptoms of individuals.

  1. Development of Tract-Specific White Matter Pathways During Early Reading Development in At-Risk Children and Typical Controls.

    PubMed

    Wang, Yingying; Mauer, Meaghan V; Raney, Talia; Peysakhovich, Barbara; Becker, Bryce L C; Sliva, Danielle D; Gaab, Nadine

    2017-04-01

    Developmental dyslexia is a neurodevelopmental disorder with a strong genetic basis. Previous studies observed white matter alterations in the left posterior brain regions in adults and school-age children with dyslexia. However, no study yet has examined the development of tract-specific white matter pathways from the pre-reading to the fluent reading stage in children at familial risk for dyslexia (FHD+) versus controls (FHD-). This study examined white matter integrity at pre-reading, beginning, and fluent reading stages cross-sectionally ( n = 78) and longitudinally (n = 45) using an automated fiber-tract quantification method. Our findings depict white matter alterations and atypical lateralization of the arcuate fasciculus at the pre-reading stage in FHD+ versus FHD- children. Moreover, we demonstrate faster white matter development in subsequent good versus poor readers and a positive association between white matter maturation and reading development using a longitudinal design. Additionally, the combination of white matter maturation, familial risk, and psychometric measures best predicted later reading abilities. Furthermore, within FHD+ children, subsequent good readers exhibited faster white matter development in the right superior longitudinal fasciculus compared with subsequent poor readers, suggesting a compensatory mechanism. Overall, our findings highlight the importance of white matter pathway maturation in the development of typical and atypical reading skills. Published by Oxford University Press 2016. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  2. Cross-lagged relationships between workplace demands, control, support, and sleep problems.

    PubMed

    Hanson, Linda L Magnusson; Åkerstedt, Torbjörn; Näswall, Katharina; Leineweber, Constanze; Theorell, Töres; Westerlund, Hugo

    2011-10-01

    Sleep problems are experienced by a large part of the population. Work characteristics are potential determinants, but limited longitudinal evidence is available to date, and reverse causation is a plausible alternative. This study examines longitudinal, bidirectional relationships between work characteristics and sleep problems. Prospective cohort/two-wave panel. Sweden. 3065 working men and women approximately representative of the Swedish workforce who responded to the 2006 and 2008 waves of the Swedish Longitudinal Occupational Survey of Health (SLOSH). N/A. Bidirectional relationships between, on the one hand, workplace demands, decision authority, and support, and, on the other hand, sleep disturbances (reflecting lack of sleep continuity) and awakening problems (reflecting feelings of being insufficiently restored), were investigated by structural equation modeling. All factors were modeled as latent variables and adjusted for gender, age, marital status, education, alcohol consumption, and job change. Concerning sleep disturbances, the best fitting models were the "forward" causal model for demands and the "reverse" causal model for support. Regarding awakening problems, reciprocal models fitted the data best. Cross-lagged analyses indicates a weak relationship between demands at Time 1 and sleep disturbances at Time 2, a "reverse" relationship from support T1 to sleep disturbances T2, and bidirectional associations between work characteristics and awakening problems. In contrast to an earlier study on demands, control, sleep quality, and fatigue, this study suggests reverse and reciprocal in addition to the commonly hypothesized causal relationships between work characteristics and sleep problems based on a 2-year time lag.

  3. 77 FR 2349 - Proposed Information Collection (Vocational Rehabilitation and Employment Longitudinal Study...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-17

    ... DEPARTMENT OF VETERANS AFFAIRS [OMB Control No. 2900-New (VR&E Longitudinal Study Survey... Rehabilitation and Employment (VR&E) Program. DATES: Written comments and recommendations on the proposed [[Page... . Please refer to ``OMB Control No. 2900--New (VR&E Longitudinal Study Survey)'' in any correspondence...

  4. Beyond Terman: Contemporary Longitudinal Studies of Giftedness and Talent.

    ERIC Educational Resources Information Center

    Subotnik, Rena F., Ed.; Arnold, Karen D., Ed.

    This volume presents 16 papers describing recent longitudinal studies of giftedness. Papers have the following titles and authors: (1) "Longitudinal Study of Giftedness and Talent" (Rena F. Subotnik and Karen D. Arnold); (2) "The Illinois Valedictorian Project: Early Adult Careers of Academically Talented Male High School Students" (Karen D.…

  5. Peer Victimization in Childhood and Internalizing Problems in Adolescence: A Prospective Longitudinal Study

    ERIC Educational Resources Information Center

    Zwierzynska, Karolina; Wolke, Dieter; Lereya, Tanya S.

    2013-01-01

    Traumatic childhood experiences have been found to predict later internalizing problems. This prospective longitudinal study investigated whether repeated and intentional harm doing by peers (peer victimization) in childhood predicts internalizing symptoms in early adolescence. 3,692 children from the Avon Longitudinal Study of Parents and…

  6. Transtheoretical Model Constructs for Physical Activity Behavior are Invariant across Time among Ethnically Diverse Adults in Hawaii

    PubMed Central

    Nigg, Claudio R; Motl, Robert W; Horwath, Caroline; Dishman, Rod K

    2012-01-01

    Objectives Physical activity (PA) research applying the Transtheoretical Model (TTM) to examine group differences and/or change over time requires preliminary evidence of factorial validity and invariance. The current study examined the factorial validity and longitudinal invariance of TTM constructs recently revised for PA. Method Participants from an ethnically diverse sample in Hawaii (N=700) completed questionnaires capturing each TTM construct. Results Factorial validity was confirmed for each construct using confirmatory factor analysis with full-information maximum likelihood. Longitudinal invariance was evidenced across a shorter (3-month) and longer (6-month) time period via nested model comparisons. Conclusions The questionnaires for each validated TTM construct are provided, and can now be generalized across similar subgroups and time points. Further validation of the provided measures is suggested in additional populations and across extended time points. PMID:22778669

  7. Emotional Awareness: A Transdiagnostic Risk Factor for Internalizing Symptoms in Children and Adolescents?

    PubMed Central

    Kranzler, Amy; Young, Jami F.; Hankin, Benjamin L.; Abela, John R. Z.; Elias, Maurice J.; Selby, Edward A.

    2015-01-01

    The current study used longitudinal data to examine the role of emotional awareness as a transdiagnostic risk factor for internalizing symptoms. Participants were 204 youth, ages 7 to 16, who completed assessments every three months for a year. Results from hierarchical mixed effects modeling indicated that low emotional awareness predicted both depressive and anxiety symptoms for up to one year follow-up. In addition, emotional awareness predicted which youth went on to experience subsequent increases in depressive and anxiety symptoms over the course of the year. Emotional awareness also mediated both the cross-sectional and the longitudinal associations between anxiety and depressive symptoms. These findings suggest that emotional awareness may constitute a transdiagnostic risk factor for the development and/or maintenance of symptoms of depression and anxiety, which has important implications for youth treatment and prevention programs. PMID:25658297

  8. Changing Attitudes Toward Euthanasia and Suicide for Terminally Ill Persons, 1977 to 2016: An Age-Period-Cohort Analysis.

    PubMed

    Attell, Brandon K

    2017-01-01

    Several longitudinal studies show that over time the American public has become more approving of euthanasia and suicide for terminally ill persons. Yet, these previous findings are limited because they derive from biased estimates of disaggregated hierarchical data. Using insights from life course sociological theory and cross-classified logistic regression models, I better account for this liberalization process by disentangling the age, period, and cohort effects that contribute to longitudinal changes in these attitudes. The results of the analysis point toward a continued liberalization of both attitudes over time, although the magnitude of change was greater for suicide compared with euthanasia. More fluctuation in the probability of supporting both measures was exhibited for the age and period effects over the cohort effects. In addition, age-based differences in supporting both measures were found between men and women and various religious affiliations.

  9. A longitudinal examination of coach and peer motivational climates in youth sport: implications for moral attitudes, well-being, and behavioral investment.

    PubMed

    Ntoumanis, Nikos; Taylor, Ian M; Thøgersen-Ntoumani, Cecilie

    2012-01-01

    Embedded in achievement goal theory (Ames, 1992; Meece, Anderman, & Anderman, 2006), this study examined how perceptions of coach and peer motivational climate in youth sport predicted moral attitudes, emotional well-being, and indices of behavioral investment in a sample of British adolescents competing in regional leagues. We adopted a longitudinal perspective, taking measures at the middle and the end of a sport season, as well as at the beginning of the following season. Multilevel modeling analyses showed that perceptions of task-involving peer and coach climates were predictive of more adaptive outcomes than were perceptions of ego-involving peer and coach climates. Predictive effects differed as a function of time and outcome variable under investigation. The results indicate the importance of considering peer influence in addition to coach influence when examining motivational climate in youth sport.

  10. Nonlinear Structured Growth Mixture Models in Mplus and OpenMx

    PubMed Central

    Grimm, Kevin J.; Ram, Nilam; Estabrook, Ryne

    2014-01-01

    Growth mixture models (GMMs; Muthén & Muthén, 2000; Muthén & Shedden, 1999) are a combination of latent curve models (LCMs) and finite mixture models to examine the existence of latent classes that follow distinct developmental patterns. GMMs are often fit with linear, latent basis, multiphase, or polynomial change models because of their common use, flexibility in modeling many types of change patterns, the availability of statistical programs to fit such models, and the ease of programming. In this paper, we present additional ways of modeling nonlinear change patterns with GMMs. Specifically, we show how LCMs that follow specific nonlinear functions can be extended to examine the presence of multiple latent classes using the Mplus and OpenMx computer programs. These models are fit to longitudinal reading data from the Early Childhood Longitudinal Study-Kindergarten Cohort to illustrate their use. PMID:25419006

  11. RHIC Au beam in Run 2014

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhang, S. Y.

    Au beam at the RHIC ramp in run 2014 is reviewed together with the run 2011 and run 2012. Observed bunch length and longitudinal emittance are compared with the IBS simulations. The IBS growth rate of the longitudinal emittance in run 2014 is similar to run 2011, and both are larger than run 2012. This is explained by the large transverse emittance at high intensity observed in run 2012, but not in run 2014. The big improvement of the AGS ramping in run 2014 might be related to this change. The importance of the injector intensity improvement in run 2014more » is emphasized, which gives rise to the initial luminosity improvement of 50% in run 2014, compared with the previous Au-Au run 2011. In addition, a modified IBS model, which is calibrated using the RHIC Au runs from 9.8 GeV/n to 100 GeV/n, is presented and used in the study.« less

  12. Abnormal skeletal growth patterns in adolescent idiopathic scoliosis--a longitudinal study until skeletal maturity.

    PubMed

    Yim, Annie P Y; Yeung, Hiu-Yan; Hung, Vivian W Y; Lee, Kwong-Man; Lam, Tsz-Ping; Ng, Bobby K W; Qiu, Yong; Cheng, Jack C Y

    2012-08-15

    A cross-sectional and prospective longitudinal study on the anthropometric parameters and growth pattern of girls with adolescent idiopathic scoliosis (AIS). To investigate the growth pattern of girls with AIS with different severities, using cross-sectional and prospective longitudinal data set in comparison with age-matched healthy controls. AIS occurs in children during their pubertal growth spurt. Although there is no clear consensus on the difference in body height between girls with AIS and healthy controls, it is generally thought that the development and curve progression in girls with AIS is closely associated with their growth rate. There is no concrete prospective longitudinal study to document clearly the growth pattern and growth rate of subjects with AIS . A total of 611 girls with AIS and 296 healthy age-matched controls were included in the study and among them, 194 girls with AIS and 116 healthy controls were followed up until skeletal maturity. The girls with AIS were grouped into moderate (AIS20) and severe curve (AIS40) groups on the basis of maximum curve magnitude at skeletal maturity. Clinical data and detailed anthropometric parameters were recorded. In the cross-sectional analysis, the groups of subjects were compared within different age groups (from the age of 12-16 yr). In the longitudinal study, linear mixed modeling with respect to age or years since menarche was employed to formulate the growth trajectory of different anthropometric parameters. In the cross-sectional analysis, the girls with AIS were generally taller, with longer arm span and lower body mass index than the healthy controls. The girls with AIS40 were found to be significantly shorter in height (P = 0.006) and arm span (P = 0.025) at the age of 12 years but caught up and overtook the control group at the age of 14 to 16 years. In the longitudinal study, the average growth rate of arm span in girls with AIS40 was significantly higher than that in girls with AIS20 (> 30%) (P = 0.004) and controls (> 70%) (P = 0.0004). The age of menarche of girls with AIS40 was significantly delayed by 5.9 months and 3.8 months when compared with the control group and girls with AIS20, respectively (P < 0.05). The growth patterns of girls with AIS with confirmed curve severities were significantly different from healthy age-matched controls. Girls with severe AIS had delayed menarche with faster skeletal growth rate during the age of 12 to 16 years. Monitoring the rate of change of arm span of girls with AIS could be an important additional clinical parameter in helping predict curve severity in girls with AIS.

  13. Determinants of father involvement with young children: Evidence from the Early Childhood Longitudinal Study-Birth Cohort.

    PubMed

    Planalp, Elizabeth M; Braungart-Rieker, Julia M

    2016-02-01

    The current study used data from the Early Childhood Longitudinal Study-Birth Cohort (ECLS-B; Snow et al., 2007) to explore determinants of resident father involvement. Families (N = 2,900) were measured at 3 time points (9 months, 2 years, and 4 years of age). Father, mother, and child factors were examined in relation to father caregiving and play. Latent change score models indicated that fathers engaged in more caregiving and play behaviors and increased at a faster rate when they more strongly identified with their role as a father. Fathers engaged in more caregiving when mothers reported higher depressive symptoms and increased in play more slowly when marital conflict was higher. In addition, a Mother Depressive Symptoms × Marital Conflict interaction emerged indicating that fathers differed in their levels of caregiving depending on mothers' report of depressive symptoms, but only when marital conflict was low. Fathers also increased in caregiving at a faster rate with girls than boys. A comprehensive framework for examining resident father involvement is presented. (c) 2016 APA, all rights reserved).

  14. Study on axial strength of a channel-shaped pultruded GFRP member

    NASA Astrophysics Data System (ADS)

    Matsumoto, Yukihiro; Satake, Chito; Nisida, Kenji

    2017-10-01

    Fiber reinforced polymers (FRP) are widely used in vehicle and aerospace applications because of their lightweight and high-strength characteristics. Additionally, FRPs are increasingly applied to building structures. However, the elastic modulus of glass fiber reinforced polymers (GFRPs) is lower than that of steel. Hence, the evaluating the buckling strength of GFRP members for design purpose is necessary. The buckling strength is determined by Euler buckling mode as well as local buckling. In this study investigated the compressive strength of GFRP members subjected to axial compression through experiments and theoretical calculations. The adopted GFRP member was a channel-shaped GFRP, which was molded via pultrusion, at various lengths. Although, the mechanical properties as longitudinal elastic modulus and fiber volume fraction and strength of GFRP members subjected, to axial can be easily evaluated, evaluating transverse elastic modulus and shear modulus in typical material tests is difficult in standard section. Therefore the composite law was used in this study. As a result, we confirmed that the axial strength of a GFRP member could be calculated by a theoretical evaluation method utilizing longitudinal elastic modulus and fiber volume fraction.

  15. The mediational role of parenting on the longitudinal relation between child personality and externalizing behavior.

    PubMed

    Prinzie, Peter; van der Sluis, Cathy M; de Haan, Amaranta D; Deković, Maja

    2010-08-01

    Building on prior cross-sectional work, this longitudinal study evaluated the proposition that maternal and paternal overreactive and authoritative parenting mediates the effect of child personality characteristics on externalizing behavior. Data from the Flemish Study on Parenting, Personality, and Problem Behavior were used in a moderated mediation analysis (N=434). Teachers rated children's Big Five characteristics, fathers and mothers rated their parenting, and 3 years later, children rated their externalizing behavior. Mediational analysis revealed both direct and indirect effects. Higher levels of Extraversion and lower levels of Benevolence were related directly to higher levels of child externalizing behavior. Higher levels of paternal authoritative parenting and lower levels of maternal overreactivity were related to lower scores on externalizing behavior. In addition, the relation between Benevolence, Emotional Stability, and externalizing behavior was partially mediated by parental overreactivity. Conscientiousness had an indirect effect on externalizing behavior through paternal authoritative parenting. Relations were not moderated by child gender. This study is of theoretical interest because the results demonstrate that parenting is a mediating mechanism that accounts for associations between personality and externalizing behavior.

  16. Impact of xerostomia on dysphagia after chemotherapy-intensity-modulated radiotherapy for oropharyngeal cancer: Prospective longitudinal study.

    PubMed

    Vainshtein, Jeffrey M; Samuels, Stuart; Tao, Yebin; Lyden, Teresa; Haxer, Marc; Spector, Matthew; Schipper, Matthew; Eisbruch, Avraham

    2016-04-01

    The purpose of this study was to assess how xerostomia affects dysphagia. Prospective longitudinal studies of 93 patients with oropharyngeal cancer treated with definitive chemotherapy-intensity-modulated radiotherapy (IMRT). Observer-rated dysphagia (ORD), patient-reported dysphagia (PRD), and patient-reported xerostomia (PRX) assessment of the swallowing mechanics by videofluoroscopy (videofluoroscopy score), and salivary flow rates, were prospectively assessed from pretherapy through 2 years. ORD grades ≥2 were rare and therefore not modeled. Of patients with no/mild videofluoroscopy abnormalities, a substantial proportion had PRD that peaked 3 months posttherapy and subsequently improved. Through 2 years, highly significant correlations were observed between PRX and PRD scores for all patients, including those with no/mild videofluoroscopy abnormalities. Both PRX and videofluoroscopy scores were highly significantly associated with PRD. On multivariate analysis, PRX score was a stronger predictor of PRD than the videofluoroscopy score. Xerostomia contributes significantly to PRD. Efforts to further decrease xerostomia, in addition to sparing parotid glands, may translate into improvements in PRD. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1605-E1612, 2016. © 2015 Wiley Periodicals, Inc.

  17. Subterahertz Longitudinal Phonon Modes Propagating in a Lipid Bilayer Immersed in an Aqueous Medium

    NASA Astrophysics Data System (ADS)

    Zakhvataev, V. E.

    2018-04-01

    The properties of subterahertz longitudinal acoustic phonon modes in the hydrophobic region of a lipid bilayer immersed in a compressible viscous aqueous medium are investigated theoretically. An approximate expression is obtained for the Mandelstam-Brillouin components of the dynamic structure factor of a bilayer. The analysis is based on a generalized hydrodynamic model of the "two-dimensional lipid bilayer + three-dimensional fluid medium" system, as well as on known sharp estimates for the frequencies and lifetimes of long-wavelength longitudinal acoustic phonons in a free hydrated lipid bilayer and in water, obtained from inelastic X-ray scattering experiments and molecular dynamics simulations. It is shown that, for characteristic values of the parameters of the membrane system, subterahertz longitudinal phonon-like excitations in the hydrophobic part of the bilayer are underdamped. In this case, the contribution of the viscous flow of the aqueous medium to the damping of a longitudinal membrane mode is small compared with the contribution of the lipid bilayer. Quantitative estimates of the damping ratio agree well with the experimental results for the vibration mode of the enzyme lysozyme in aqueous solution [1]. It is also shown that a coupling between longitudinal phonon modes of the bilayer and relaxation processes in its fluid environment gives rise to an additional peak in the scattering spectrum, which corresponds to a non-propagating mode.

  18. A Model of Manual Control with Perspective Scene Viewing

    NASA Technical Reports Server (NTRS)

    Sweet, Barbara Townsend

    2013-01-01

    A model of manual control during perspective scene viewing is presented, which combines the Crossover Model with a simpli ed model of perspective-scene viewing and visual- cue selection. The model is developed for a particular example task: an idealized constant- altitude task in which the operator controls longitudinal position in the presence of both longitudinal and pitch disturbances. An experiment is performed to develop and vali- date the model. The model corresponds closely with the experimental measurements, and identi ed model parameters are highly consistent with the visual cues available in the perspective scene. The modeling results indicate that operators used one visual cue for position control, and another visual cue for velocity control (lead generation). Additionally, operators responded more quickly to rotation (pitch) than translation (longitudinal).

  19. Associations Among Pubertal Development, Empathic Ability, and Neural Responses While Witnessing Peer Rejection in Adolescence

    PubMed Central

    Masten, Carrie L.; Eisenberger, Naomi I.; Pfeifer, Jennifer H.; Colich, Natalie L.; Dapretto, Mirella

    2012-01-01

    Links among concurrent and longitudinal changes in pubertal development and empathic ability from age 10 to 13 and neural responses while witnessing peer rejection at age 13 were examined in 16 participants. More advanced pubertal development at age 13, and greater longitudinal increases in pubertal development, related to increased activity in regions underlying cognitive aspects of empathy. Likewise, at age 13 greater perspective taking related to activity in cognitive empathy-related regions; however, affective components of empathy (empathic concern and personal distress) were additionally associated with activity in affective pain-related regions. Longitudinal increases in empathic ability related to cognitive and affective empathy-related circuitry. Findings provide preliminary evidence that physical and cognitive-emotional development relate to adolescents’ neural responses when witnessing peer rejection. PMID:23379360

  20. Studying the Longitudinal Study. I. Introduction: Do Impromptu Essays Show Changes in Critical Thinking over the Span of College? Cautions and Insights from a Pilot Case Study.

    ERIC Educational Resources Information Center

    Clark, Francelia

    The problematic results of longitudinal studies on college writing indicate the need for multidimensional studies to be able to explore perceptible changes in students' writing. Accordingly a small pilot case study, to explore the promise and the limitations of doing a longitudinal multidimensional study, investigated whether impromptu essays…

  1. What You Don't Know Can Hurt You: Missing Data and Partial Credit Model Estimates

    PubMed Central

    Thomas, Sarah L.; Schmidt, Karen M.; Erbacher, Monica K.; Bergeman, Cindy S.

    2017-01-01

    The authors investigated the effect of Missing Completely at Random (MCAR) item responses on partial credit model (PCM) parameter estimates in a longitudinal study of Positive Affect. Participants were 307 adults from the older cohort of the Notre Dame Study of Health and Well-Being (Bergeman and Deboeck, 2014) who completed questionnaires including Positive Affect items for 56 days. Additional missing responses were introduced to the data, randomly replacing 20%, 50%, and 70% of the responses on each item and each day with missing values, in addition to the existing missing data. Results indicated that item locations and person trait level measures diverged from the original estimates as the level of degradation from induced missing data increased. In addition, standard errors of these estimates increased with the level of degradation. Thus, MCAR data does damage the quality and precision of PCM estimates. PMID:26784376

  2. Longitudinal Changes in Access to Health Care by Immigrant Status among Older Adults: The Importance of Health Insurance as a Mediator

    ERIC Educational Resources Information Center

    Choi, Sunha

    2011-01-01

    Purpose: This longitudinal study examined the role of health insurance in access to health care among older immigrants. Design and Methods: Using data from the Second Longitudinal Study of Aging, the longitudinal trajectories of having a usual source of care were compared between 3 groups (all 70+ years): (a) late-life immigrants with less than 15…

  3. Stress Process of Illicit Drug Use among U.S. Immigrants' Adolescent Children: A Longitudinal Study

    ERIC Educational Resources Information Center

    Choo, Hyekyung

    2012-01-01

    This study examined a full path model of stress process for predicting illicit drug use among Asian and Latino immigrants' adolescent children. Using 2-year longitudinal data (National Longitudinal Study of Adolescent Health) from a sample of adolescents with Asian or Latino immigrant parents (N = 2,353), the study explored structural…

  4. SALGOT - Stroke Arm Longitudinal study at the University of Gothenburg, prospective cohort study protocol

    PubMed Central

    2011-01-01

    Background Recovery patterns of upper extremity motor function have been described in several longitudinal studies, but most of these studies have had selected samples, short follow up times or insufficient outcomes on motor function. The general understanding is that improvements in upper extremity occur mainly during the first month after the stroke incident and little if any, significant recovery can be gained after 3-6 months. The purpose of this study is to describe the recovery of upper extremity function longitudinally in a non-selected sample initially admitted to a stroke unit with first ever stroke, living in Gothenburg urban area. Methods/Design A sample of 120 participants with a first-ever stroke and impaired upper extremity function will be consecutively included from an acute stroke unit and followed longitudinally for one year. Assessments are performed at eight occasions: at day 3 and 10, week 3, 4 and 6, month 3, 6 and 12 after onset of stroke. The primary clinical outcome measures are Action Research Arm Test and Fugl-Meyer Assessment for Upper Extremity. As additional measures, two new computer based objective methods with kinematic analysis of arm movements are used. The ABILHAND questionnaire of manual ability, Stroke Impact Scale, grip strength, spasticity, pain, passive range of motion and cognitive function will be assessed as well. At one year follow up, two patient reported outcomes, Impact on Participation and Autonomy and EuroQol Quality of Life Scale, will be added to cover the status of participation and aspects of health related quality of life. Discussion This study comprises a non-selected population with first ever stroke and impaired arm function. Measurements are performed both using traditional clinical assessments as well as computer based measurement systems providing objective kinematic data. The ICF classification of functioning, disability and health is used as framework for the selection of assessment measures. The study design with several repeated measurements on motor function will give us more confident information about the recovery patterns after stroke. This knowledge is essential both for optimizing rehabilitation planning as well as providing important information to the patient about the recovery perspectives. Trial registration ClinicalTrials.gov: NCT01115348 PMID:21612620

  5. Investigation of 2‐stage meta‐analysis methods for joint longitudinal and time‐to‐event data through simulation and real data application

    PubMed Central

    Tudur Smith, Catrin; Gueyffier, François; Kolamunnage‐Dona, Ruwanthi

    2017-01-01

    Background Joint modelling of longitudinal and time‐to‐event data is often preferred over separate longitudinal or time‐to‐event analyses as it can account for study dropout, error in longitudinally measured covariates, and correlation between longitudinal and time‐to‐event outcomes. The joint modelling literature focuses mainly on the analysis of single studies with no methods currently available for the meta‐analysis of joint model estimates from multiple studies. Methods We propose a 2‐stage method for meta‐analysis of joint model estimates. These methods are applied to the INDANA dataset to combine joint model estimates of systolic blood pressure with time to death, time to myocardial infarction, and time to stroke. Results are compared to meta‐analyses of separate longitudinal or time‐to‐event models. A simulation study is conducted to contrast separate versus joint analyses over a range of scenarios. Results Using the real dataset, similar results were obtained by using the separate and joint analyses. However, the simulation study indicated a benefit of use of joint rather than separate methods in a meta‐analytic setting where association exists between the longitudinal and time‐to‐event outcomes. Conclusions Where evidence of association between longitudinal and time‐to‐event outcomes exists, results from joint models over standalone analyses should be pooled in 2‐stage meta‐analyses. PMID:29250814

  6. Convenience food in the diet of children and adolescents: consumption and composition.

    PubMed

    Alexy, Ute; Sichert-Hellert, Wolfgang; Rode, Tabea; Kersting, Mathilde

    2008-02-01

    Despite an increasing trend towards the use of convenience food, there is to date little debate on it in the nutritional sciences. In the present study, we present and evaluate data on consumption frequencies and composition of savoury convenience food in German families using data from the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) Study. The DONALD Study is an ongoing, longitudinal (open cohort) study (started 1985), collecting detailed data on diet, development, and metabolism in infants, children and adolescents. Dietary intake was measured by yearly repeated 3 d weighed dietary records (n 1558) in 554 subjects (278 boys; 276 girls), 3-18 years old, between 2003 and 2006. A total of 1345 (86%) 3 d dietary records mentioned consumption of at least one convenience food. Convenience food consumption (percentage of total food intake, g/d) increased with age from approximately 3% in the 3-8 year olds to 7% in 14-18-year-old boys and 5% in 14-18-year-old girls (P < 0.0001) but remained constant during the study period. Convenience foods contributed more to total fat (g/d) (P < 0.001) and less to total carbohydrate (P < 0.0001) than to total energy (kJ/d) intake. The 700 convenience-food products recorded by our sample had on average fourteen ingredients; 4% were flavourings and 16% were food additives. In conclusion, convenience foods were widely consumed by our sample of German children and adolescents and their consumption increased with age. The composition of convenience food was characterised by a high fat content and a high number of flavourings and food additives.

  7. Cohort Profile: The Social Environment and Biomarkers of Aging Study (SEBAS) in Taiwan

    PubMed Central

    Cornman, Jennifer C; Glei, Dana A; Goldman, Noreen; Chang, Ming-Cheng; Lin, Hui-Sheng; Chuang, Yi-Li; Hurng, Baai-Shyun; Lin, Yu-Hsuan; Lin, Shu-Hui; Liu, I-Wen; Liu, Hsia-Yuan; Weinstein, Maxine

    2016-01-01

    The Social Environment and Biomarkers of Aging Study (SEBAS) is a nationally representative longitudinal survey of Taiwanese middle-aged and older adults. It adds the collection of biomarkers and performance assessments to the Taiwan Longitudinal Study of Aging (TLSA), a nationally representative study of adults aged 60 and over, including the institutionalized population. The TLSA began in 1989, with follow-ups approximately every 3 years; younger refresher cohorts were added in 1996 and 2003. The first wave of SEBAS, based on a sub-sample of respondents from the 1999 TLSA, was conducted in 2000. A total of 1023 respondents completed both a face-to-face home interview and, several weeks later, a hospital-based physical examination. In addition to a 12-h (7 pm–7 am) urine specimen collected the night before and a fasting blood specimen collected during the examination, trained staff measured blood pressure, height, weight and waist and hip circumferences. A second wave of SEBAS was conducted in 2006 using a similar protocol to SEBAS 2000, but with the addition of performance assessments conducted by the interviewers at the end of the home interview. Both waves of SEBAS also included measures of health status (physical, emotional, cognitive), health behaviours, social relationships and exposure to stressors. The SEBAS data, which are publicly available at [http://www.icpsr.umich.edu/icpsrweb/NACDA/studies/3792/version/5], allow researchers to explore the relationships among life challenges, the social environment and health and to examine the antecedents, correlates and consequences of change in biological measures and health. PMID:25205853

  8. Trajectories of Attention Deficit Hyperactivity Disorder and Oppositional Defiant Disorder Symptoms as Precursors of Borderline Personality Disorder Symptoms in Adolescent Girls

    PubMed Central

    Stepp, Stephanie D.; Burke, Jeffrey D.; Hipwell, Alison E.; Loeber, Rolf

    2011-01-01

    Little empirical evidence exists regarding the developmental links between childhood psychopathology and borderline personality disorder (BPD) in adolescence. The current study addresses this gap by examining symptoms of attention deficit hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD) as potential precursors. ADHD and BPD share clinical features of impulsivity, poor self-regulation, and executive dysfunction, while ODD and BPD share features of anger and interpersonal turmoil. The study is based on annual, longitudinal data from the two oldest cohorts in the Pittsburgh Girls Study (N = 1233). We used piecewise latent growth curve models of ADHD and ODD scores from age 8–10 and 10–13 years to examine the prospective associations between dual trajectories of ADHD and ODD symptom severity and later BPD symptoms at age 14 in girls. To examine the specificity of these associations, we also included conduct disorder (CD) and depression symptom severity at age 14 as additional outcomes. We found that higher levels of ADHD and ODD scores at age 8 uniquely predicted BPD symptoms at age 14. Additionally, the rate of growth in ADHD scores from age 10–13 and the rate of growth in ODD scores from 8–10 uniquely predicted higher BPD symptoms at age 14. This study adds to the literature on the early development of BPD by providing the first longitudinal study to examine ADHD and ODD symptom trajectories as specific childhood precursors of BPD symptoms in adolescent girls. PMID:21671009

  9. Are obsessive-compulsive personality traits associated with a poor outcome in anorexia nervosa? A systematic review of randomized controlled trials and naturalistic outcome studies.

    PubMed

    Crane, Anna M; Roberts, Marion E; Treasure, Janet

    2007-11-01

    Obsessive-compulsive personality disorder (OCPD) traits are commonly associated with anorexia nervosa (AN). The aim of this review was to systematically search the literature to examine whether OCPD traits have an impact on the outcome of AN. A systematic electronic search of the literature (using Medline, PsycINFO, and the Cochrane Central Register of Controlled Trials) was undertaken to identify relevant publications (randomized controlled trials (RCT's) and naturalistic studies), until February 2006. Eleven prospective longitudinal studies and 12 RCT's met criteria for inclusion. A meta-analysis was not feasible as the studies were too heterogeneous. Just over half of published longitudinal studies found that OCPD traits were associated with a negative outcome in AN. Additionally, results from three RCTs suggested that these traits may moderate outcome. OCPD traits were reduced after treatment in five RCTs. There is tentative support to suggest that individuals with AN and concomitant OCPD traits have a poorer prognosis, and that these traits moderate outcome. A reduction in these traits may mediate this change. An individualized case formulation with treatment tailored to OCPD traits may improve the outcome of AN. (c) 2007 by Wiley Periodicals, Inc.

  10. Review of Non-Respiratory, Non-Cancer Physical Health Conditions from Exposure to the World Trade Center Disaster

    PubMed Central

    Gargano, Lisa M.; Mantilla, Kimberly; Fairclough, Monique; Yu, Shengchao; Brackbill, Robert M.

    2018-01-01

    After the World Trade Center attacks on 11 September 2001 (9/11), multiple cohorts were developed to monitor the health outcomes of exposure. Respiratory and cancer effects have been covered at length. This current study sought to review the literature on other physical conditions associated with 9/11-exposure. Researchers searched seven databases for literature published in English from 2002 to October 2017, coded, and included articles for health condition outcome, population, 9/11-exposures, and comorbidity. Of the 322 titles and abstracts screened, 30 studies met inclusion criteria, and of these, 28 were from three cohorts: the World Trade Center Health Registry, Fire Department of New York, and World Trade Center Health Consortium. Most studies focused on rescue and recovery workers. While many of the findings were consistent across different populations and supported by objective measures, some of the less studied conditions need additional research to substantiate current findings. In the 16 years after 9/11, longitudinal cohorts have been essential in investigating the health consequences of 9/11-exposure. Longitudinal studies will be vital in furthering our understanding of these emerging conditions, as well as treatment effectiveness. PMID:29401643

  11. 77 FR 20885 - Agency Information Collection (Vocational Rehabilitation and Employment Longitudinal Study Survey...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-06

    ... DEPARTMENT OF VETERANS AFFAIRS [OMB Control No. 2900-New (VR&E Longitudinal Study Survey)] Agency... Building, Room 10235, Washington, DC 20503 (202) 395-7316. Please refer to ``OMB Control No. 2900-New (VR&E....gov . Please refer to ``OMB Control No. 2900-New (VR&E Longitudinal Study Survey)''. SUPPLEMENTARY...

  12. The Timing of Maternal Depressive Symptoms and Child Cognitive Development: A Longitudinal Study

    ERIC Educational Resources Information Center

    Evans, Jonathan; Melotti, Roberto; Heron, Jon; Ramchandani, Paul; Wiles, Nicola; Murray, Lynne; Stein, Alan

    2012-01-01

    Background: Maternal depression is known to be associated with impairments in child cognitive development, although the effect of timing of exposure to maternal depression is unclear. Methods: Data collected for the Avon Longitudinal Study of Parents and Children, a longitudinal study beginning in pregnancy, included self-report measures of…

  13. National Prevalence Rates of Bully Victimization among Students with Disabilities in the United States

    ERIC Educational Resources Information Center

    Blake, Jamilia J.; Lund, Emily M.; Zhou, Qiong; Kwok, Oi-man; Benz, Michael R.

    2012-01-01

    This study examined the prevalence rates of bully victimization and risk for repeated victimization among students with disabilities using the Special Education Elementary Longitudinal Study and the National Longitudinal Transition Study-2 longitudinal datasets. Results revealed that a prevalence rate ranging from 24.5% in elementary school to…

  14. Fears in Czech Adolescents: A Longitudinal Study

    ERIC Educational Resources Information Center

    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…

  15. Reducing Bias Due to Systematic Attrition in Longitudinal Studies: The Benefits of Multiple Imputation

    ERIC Educational Resources Information Center

    Asendorpf, Jens B.; van de Schoot, Rens; Denissen, Jaap J. A.; Hutteman, Roos

    2014-01-01

    Most longitudinal studies are plagued by drop-out related to variables at earlier assessments (systematic attrition). Although systematic attrition is often analysed in longitudinal studies, surprisingly few researchers attempt to reduce biases due to systematic attrition, even though this is possible and nowadays technically easy. This is…

  16. Nonlinear Gompertz Curve Models of Achievement Gaps in Mathematics and Reading

    ERIC Educational Resources Information Center

    Cameron, Claire E.; Grimm, Kevin J.; Steele, Joel S.; Castro-Schilo, Laura; Grissmer, David W.

    2015-01-01

    This study examined achievement trajectories in mathematics and reading from school entry through the end of middle school with linear and nonlinear growth curves in 2 large longitudinal data sets (National Longitudinal Study of Youth--Children and Young Adults and Early Childhood Longitudinal Study--Kindergarten Cohort [ECLS-K]). The S-shaped…

  17. Paternal Alcoholism, Family Functioning, and Infant Mental Health

    ERIC Educational Resources Information Center

    Fitzgerald, Hiram E.; Eiden, Rina Das

    2007-01-01

    The authors share results from two longitudinal studies exploring the impact of father's alcohol use on child development. The Michigan Longitudinal Study (MLS) has followed a sample of alcoholic families with 3-5 year old children for 20 years. The Buffalo Longitudinal Study (BLS) has followed a sample of alcoholic and nonalcoholic families…

  18. The PANDAS subgroup of tic disorders and childhood-onset obsessive-compulsive disorder.

    PubMed

    Martino, Davide; Defazio, Giovanni; Giovannoni, Gavin

    2009-12-01

    Diagnosis and treatment of the PANDAS (pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections) variant of Gilles de la Tourette syndrome (GTS) and childhood-onset obsessive-compulsive disorder (OCD) are still controversial issues. Most cross-sectional studies confirm a significant association between GTS and the development of an immune response against group A beta-hemolytic streptococcus (GABHS). Moreover, longitudinal retrospective studies suggest that a recent exposure to GABHS might be a risk factor for the onset of tics and obsessive-compulsive symptoms. However, further evidence from longitudinal prospective research is needed to verify whether a temporal association between GABHS infections and symptom exacerbations is a useful and reliable criterion for the diagnosis of PANDAS. In addition, preliminary results suggest that the PANDAS spectrum might be enlarged to include attention deficit/hyperactivity disorder. Although a number of immunological biomarkers have been proposed as markers of the PANDAS variant, at present, none of these has been conclusively proved useful to diagnose and monitor disease course in children with a suspicion of PANDAS. Finally, despite their empirical use in community settings, we still lack conclusive, evidence-based data regarding the usefulness of antibiotic and immunomodulatory treatments in children with PANDAS. Given the relevance of this topic for general pediatric health, additional research efforts to solve all the pending issues and the hottest points of debate are warranted.

  19. A Longitudinal Examination of the Relation Between Internalizing Problem Behaviors and Early Adolescent Cigarette Smoking.

    PubMed

    Aloise-Young, Patricia A; Zaleski, Adam C; Swaim, Randall C

    2017-01-01

    The purpose of the present study was to investigate the longitudinal relation between internalizing problem behaviors (measured with the anxious/depressed and somatic complaints subscales of the Achenbach Teacher's Report Form) and self-reported cigarette smoking behavior and intentions during early adolescence. In addition, a possible mediating role of perceived harm was investigated. Sixth graders and their teachers were surveyed in the sixth grade and students were surveyed again in the seventh grade. Smoking behavior and intentions were assessed with five items including lifetime use, 30-day use, tobacco user status (nonsmoker to heavy smoker), and two intentions/behavioral expectations items. In addition to perceived harm from smoking, reasons for smoking and reasons for not smoking were included on the survey. As hypothesized, teacher reports of sixth-grade internalizing problem behaviors were negatively related to seventh-grade smoking behavior and intentions. Moreover, perceived harm from smoking was negatively related to smoking and intentions. The hypothesized mediating role of perceived harm in the internalizing to smoking relationship was not supported. Potential differences in the relation between internalizing and smoking across adolescence are discussed. Specifically, the results of the present study and an examination of prior literature suggest that in early adolescence internalizing problems are negatively related to cigarette smoking, whereas in middle and late adolescence the opposite is true.

  20. Outdoor temperature, precipitation, and wind speed affect physical activity levels in children: a longitudinal cohort study

    PubMed Central

    Edwards, Nicholas M.; Myer, Gregory D.; Kalkwarf, Heidi J.; Woo, Jessica G.; Khoury, Philip R.; Hewett, Timothy E.; Daniels, Stephen R.

    2015-01-01

    Objective Evaluate effects of local weather conditions on physical activity in early childhood. Methods Longitudinal prospective cohort study of 372 children, 3 years old at enrollment, drawn from a major US metropolitan community. Accelerometer-measured (RT3) physical activity was collected every 4 months over 5 years and matched with daily weather measures: day length, heating/cooling degrees (degrees mean temperature < 65°F or ≥ 65°F, respectively), wind, and precipitation. Mixed regression analyses, adjusted for repeated measures, were used to test the relationship between weather and physical activity. Results Precipitation and wind speed were negatively associated with total physical activity and moderate-vigorous physical activity (P<0.0001). Heating and cooling degrees were negatively associated with total physical activity and moderate-vigorous physical activity and positively associated with inactivity (all P<0.0001), independent of age, sex, race, BMI, day length, wind, and precipitation. For every 10 additional heating degrees there was a five-minute daily reduction in moderate-vigorous physical activity. For every additional 10 cooling degrees there was a 17-minute reduction in moderate-vigorous physical activity. Conclusions Inclement weather (higher/lower temperature, greater wind speed, more rain/snow) is associated with less physical activity in young children. These deleterious effects should be considered when planning physical activity research, interventions, and policies. PMID:25423667

  1. Cloud-Based Service Information System for Evaluating Quality of Life after Breast Cancer Surgery.

    PubMed

    Kao, Hao-Yun; Wu, Wen-Hsiung; Liang, Tyng-Yeu; Lee, King-The; Hou, Ming-Feng; Shi, Hon-Yi

    2015-01-01

    Although recent studies have improved understanding of quality of life (QOL) outcomes of breast conserving surgery, few have used longitudinal data for more than two time points, and few have examined predictors of QOL over two years. Additionally, the longitudinal data analyses in such studies rarely apply the appropriate statistical methodology to control for censoring and inter-correlations arising from repeated measures obtained from the same patient pool. This study evaluated an internet-based system for measuring longitudinal changes in QOL and developed a cloud-based system for managing patients after breast conserving surgery. This prospective study analyzed 657 breast cancer patients treated at three tertiary academic hospitals. Related hospital personnel such as surgeons and other healthcare professionals were also interviewed to determine the requirements for an effective cloud-based system for surveying QOL in breast cancer patients. All patients completed the SF-36, Quality of Life Questionnaire (QLQ-C30) and its supplementary breast cancer measure (QLQ-BR23) at baseline, 6 months, 1 year, and 2 years postoperatively. The 95% confidence intervals for differences in responsiveness estimates were derived by bootstrap estimation. Scores derived by these instruments were interpreted by generalized estimating equation before and after surgery. All breast cancer surgery patients had significantly improved QLQ-C30 and QLQ-BR23 subscale scores throughout the 2-year follow-up period (p<0.05). During the study period, QOL generally had a negative association with advanced age, high Charlson comorbidity index score, tumor stage III or IV, previous chemotherapy, and long post-operative LOS. Conversely, QOL was positively associated with previous radiotherapy and hormone therapy. Additionally, patients with high scores for preoperative QOL tended to have high scores for QLQ-C30, QLQ-BR23 and SF-36 subscales. Based on the results of usability testing, the five constructs were rated on a Likert scale from 1-7 as follows: system usefulness (5.6±1.8), ease of use (5.6±1.5), information quality (5.4±1.4), interface quality (5.5±1.4), and overall satisfaction (5.5±1.6). The current trend in clinical medicine is applying therapies and interventions that improve QOL. Therefore, a potentially vast amount of internet-based QOL data is available for use in defining patient populations that may benefit from therapeutic intervention. Additionally, before undergoing breast conserving surgery, patients should be advised that their postoperative QOL depends not only on the success of the surgery, but also on their preoperative functional status.

  2. Cloud-Based Service Information System for Evaluating Quality of Life after Breast Cancer Surgery

    PubMed Central

    Kao, Hao-Yun; Wu, Wen-Hsiung; Liang, Tyng-Yeu; Lee, King-The; Hou, Ming-Feng; Shi, Hon-Yi

    2015-01-01

    Objective Although recent studies have improved understanding of quality of life (QOL) outcomes of breast conserving surgery, few have used longitudinal data for more than two time points, and few have examined predictors of QOL over two years. Additionally, the longitudinal data analyses in such studies rarely apply the appropriate statistical methodology to control for censoring and inter-correlations arising from repeated measures obtained from the same patient pool. This study evaluated an internet-based system for measuring longitudinal changes in QOL and developed a cloud-based system for managing patients after breast conserving surgery. Methods This prospective study analyzed 657 breast cancer patients treated at three tertiary academic hospitals. Related hospital personnel such as surgeons and other healthcare professionals were also interviewed to determine the requirements for an effective cloud-based system for surveying QOL in breast cancer patients. All patients completed the SF-36, Quality of Life Questionnaire (QLQ-C30) and its supplementary breast cancer measure (QLQ-BR23) at baseline, 6 months, 1 year, and 2 years postoperatively. The 95% confidence intervals for differences in responsiveness estimates were derived by bootstrap estimation. Scores derived by these instruments were interpreted by generalized estimating equation before and after surgery. Results All breast cancer surgery patients had significantly improved QLQ-C30 and QLQ-BR23 subscale scores throughout the 2-year follow-up period (p<0.05). During the study period, QOL generally had a negative association with advanced age, high Charlson comorbidity index score, tumor stage III or IV, previous chemotherapy, and long post-operative LOS. Conversely, QOL was positively associated with previous radiotherapy and hormone therapy. Additionally, patients with high scores for preoperative QOL tended to have high scores for QLQ-C30, QLQ-BR23 and SF-36 subscales. Based on the results of usability testing, the five constructs were rated on a Likert scale from 1–7 as follows: system usefulness (5.6±1.8), ease of use (5.6±1.5), information quality (5.4±1.4), interface quality (5.5±1.4), and overall satisfaction (5.5±1.6). Conclusions The current trend in clinical medicine is applying therapies and interventions that improve QOL. Therefore, a potentially vast amount of internet-based QOL data is available for use in defining patient populations that may benefit from therapeutic intervention. Additionally, before undergoing breast conserving surgery, patients should be advised that their postoperative QOL depends not only on the success of the surgery, but also on their preoperative functional status. PMID:26422018

  3. Can favorable psychosocial work conditions and high work dedication protect against the occurrence of work-related musculoskeletal disorders?

    PubMed

    Joling, Catelijne I; Blatter, Birgitte M; Ybema, Jan Fekke; Bongers, Paulien M

    2008-10-01

    This study investigated whether work dedication and job resources are longitudinally related to work-related musculoskeletal disorders and whether job resources buffer the impact of job demands on these disorders? Data were used from a longitudinal three-phase study (2004, 2005, 2006) on health at work among a sample of Dutch workers. The first survey was sent in 2004 by e-mail to 3100 members of an existing panel. For the analyses, 1522 participants were included with full longitudinal data. The analyses were performed using an autoregressive model with generalized estimating equations. The job-resource quality of communication was found to predict the risk of work-related musculoskeletal disorders over time. This effect was not mediated by work dedication. A high quality of communication was also found to buffer the negative effects of a high physical workload on the risk of work-related musculoskeletal disorders. Furthermore, a low level of social support by colleagues was found to buffer the negative effect of a medium physical workload on work-related musculoskeletal disorders. This study shows that job resources are not only important for promoting work dedication, but may also moderate the negative impact of high job demands on the risk of work-related musculoskeletal disorders. With respect to social support, the question is raised of whether this can also work negatively. The results of this study imply that, besides avoiding or reducing risks to health in the workplace and lowering job demands, strengthening job resources may additionally buffer harmful effects of job demands on musculoskeletal health.

  4. An Inviscid Computational Study of Three '07 Mars Lander Aeroshell Configurations Over a Mach Number Range of 2.3 to 4.5

    NASA Technical Reports Server (NTRS)

    Prabhu, Ramadas K.; Sutton, Kenneth (Technical Monitor)

    2001-01-01

    This report documents the results of a study conducted to compute the inviscid longitudinal aerodynamic characteristics of three aeroshell configurations of the proposed '07 Mars lander. This was done in support of the activity to design a smart lander for the proposed '07 Mars mission. In addition to the three configurations with tabs designated as the shelf, the canted, and the Ames, the baseline configuration (without tab) was also studied. The unstructured grid inviscid CFD software FELISA was used, and the longitudinal aerodynamic characteristics of the four configurations were computed for Mach number of 2.3, 2.7, 3.5, and 4.5, and for an angle of attack range of -4 to 20 degrees. Wind tunnel tests had been conducted on scale models of these four configurations in the Unitary Plan Wind Tunnel, NASA Langley Research Center. Present computational results are compared with the data from these tests. Some differences are noticed between the two results, particularly at the lower Mach numbers. These differences are attributed to the pressures acting on the aft body. Most of the present computations were done on the forebody only. Additional computations were done on the full body (forebody and afterbody) for the baseline and the Shelf configurations. Results of some computations done (to simulate flight conditions) with the Mars gas option and with an effective gamma are also included.

  5. Predicting Continuance—Findings from a Longitudinal Study of Older Adults Using an eHealth Newsletter

    PubMed Central

    Forquer, Heather A.; Christensen, John L.; Tan, Andy S.L.

    2014-01-01

    While eHealth technologies are promisingly efficient and widespread, theoretical frameworks capable of predicting long-term use, termed continuance, are lacking. Attempts to extend prominent information technology (IT) theories to the area of eHealth have been limited by small sample sizes, cross-sectional designs, self-reported as opposed to actual use measures, and a focus on technology adoption rather than continuance. To address these gaps in the literature, the present analysis includes empirical evidence of actual use of an eHealth technology over the course of one year. This large (n=4,570) longitudinal study focuses on older adults, a population with many health needs, and among whom eHealth use may be particularly important. With three measurement points over the course of a year, this study examined the effects of utilitarian and hedonic beliefs on the continued use of an eHealth newsletter using constructs from IT adoption and continuance theories. Additional analyses compared the relative strength of intentions compared to earlier use in predicting later use. Usage intention was strongly predicted by both hedonic beliefs and utilitarian beliefs. In addition, utilitarian beliefs had both direct effects on intention, as well as indirect effects, mediated by hedonic beliefs. While intention predicted subsequent use, earlier use was a significantly stronger predictor of use than intention. These findings make a theoretical contribution to an emerging literature by shedding light on the complex interplay of reasoned action and automaticity in the context of eHealth continuance. PMID:24446900

  6. Predicting continuance-findings from a longitudinal study of older adults using an eHealth newsletter.

    PubMed

    Forquer, Heather A; Christensen, John L; Tan, Andy S L

    2014-01-01

    While eHealth technologies are promisingly efficient and widespread, theoretical frameworks capable of predicting long-term use, termed continuance, are lacking. Attempts to extend prominent information technology (IT) theories to the area of eHealth have been limited by small sample sizes, cross-sectional designs, self-reported as opposed to actual use measures, and a focus on technology adoption rather than continuance. To address these gaps in the literature, this analysis includes empirical evidence of actual use of an eHealth technology over the course of one year. This large (n = 4,570) longitudinal study focuses on older adults, a population with many health needs and among whom eHealth use may be particularly important. With three measurement points over the course of a year, this study examined the effects of utilitarian and hedonic beliefs on the continued use of an eHealth newsletter using constructs from IT adoption and continuance theories. Additional analyses compared the relative strength of intentions compared to earlier use in predicting later use. Usage intention was strongly predicted by both hedonic beliefs and utilitarian beliefs. In addition, utilitarian beliefs had both direct effects on intention and indirect effects, mediated by hedonic beliefs. While intention predicted subsequent use, earlier use was a significantly stronger predictor of use than intention. These findings make a theoretical contribution to an emerging literature by shedding light on the complex interplay of reasoned action and automaticity in the context of eHealth continuance.

  7. Cohort Profile: The ‘Children of the 90s’—the index offspring of the Avon Longitudinal Study of Parents and Children

    PubMed Central

    Boyd, Andy; Golding, Jean; Macleod, John; Lawlor, Debbie A; Fraser, Abigail; Henderson, John; Molloy, Lynn; Ness, Andy; Ring, Susan; Davey Smith, George

    2013-01-01

    The Avon Longitudinal Study of Parents and Children (ALSPAC) is a transgenerational prospective observational study investigating influences on health and development across the life course. It considers multiple genetic, epigenetic, biological, psychological, social and other environmental exposures in relation to a similarly diverse range of health, social and developmental outcomes. Recruitment sought to enrol pregnant women in the Bristol area of the UK during 1990–92; this was extended to include additional children eligible using the original enrolment definition up to the age of 18 years. The children from 14 541 pregnancies were recruited in 1990–92, increasing to 15 247 pregnancies by the age of 18 years. This cohort profile describes the index children of these pregnancies. Follow-up includes 59 questionnaires (4 weeks–18 years of age) and 9 clinical assessment visits (7–17 years of age). The resource comprises a wide range of phenotypic and environmental measures in addition to biological samples, genetic (DNA on 11 343 children, genome-wide data on 8365 children, complete genome sequencing on 2000 children) and epigenetic (methylation sampling on 1000 children) information and linkage to health and administrative records. Data access is described in this article and is currently set up as a supported access resource. To date, over 700 peer-reviewed articles have been published using ALSPAC data. PMID:22507743

  8. Longitudinal multigroup invariance analysis of the satisfaction with food-related life scale in university students.

    PubMed

    Schnettler, Berta; Miranda, Horacio; Miranda-Zapata, Edgardo; Salinas-Oñate, Natalia; Grunert, Klaus G; Lobos, Germán; Sepúlveda, José; Orellana, Ligia; Hueche, Clementina; Bonilla, Héctor

    2017-06-01

    This study examined longitudinal measurement invariance in the Satisfaction with Food-related Life (SWFL) scale using follow-up data from university students. We examined this measure of the SWFL in different groups of students, separated by various characteristics. Through non-probabilistic longitudinal sampling, 114 university students (65.8% female, mean age: 22.5) completed the SWFL questionnaire three times, over intervals of approximately one year. Confirmatory factor analysis was used to examine longitudinal measurement invariance. Two types of analysis were conducted: first, a longitudinal invariance by time, and second, a multigroup longitudinal invariance by sex, age, socio-economic status and place of residence during the study period. Results showed that the 3-item version of the SWFL exhibited strong longitudinal invariance (equal factor loadings and equal indicator intercepts). Longitudinal multigroup invariance analysis also showed that the 3-item version of the SWFL displays strong invariance by socio-economic status and place of residence during the study period over time. Nevertheless, it was only possible to demonstrate equivalence of the longitudinal factor structure among students of both sexes, and among those older and younger than 22 years. Generally, these findings suggest that the SWFL scale has satisfactory psychometric properties for longitudinal measurement invariance in university students with similar characteristics as the students that participated in this research. It is also possible to suggest that satisfaction with food-related life is associated with sex and age. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Stabilized single-longitudinal-mode erbium fibre laser employing silicon-micro-ring resonator and saturable absorber

    NASA Astrophysics Data System (ADS)

    Hsu, Yung; Yeh, Chien-Hung; Chow, Chi-Wai; Chang, Yuan-Chia; Cheng, Hao-Yun

    2018-07-01

    In the paper, a wavelength-tunable erbium-doped fiber (EDF) ring laser with stable single-longitudinal-mode (SLM) oscillation is proposed and investigated. Here, a silicon-micro-ring-resonator can be applied in a laser cavity for tuning wavelength in the C-band range. To complete the SLM oscillation, an unpumped EDF-based saturable absorber is used to act as ultra-narrowband filter for suppressing other oscillation modes. Additionally, the output stabilities of power and wavelength in the proposed EDF ring laser are also executed and discussed.

  10. Stability and change in adult personality over 6 years: findings from the Victoria Longitudinal Study.

    PubMed

    Small, Brent J; Hertzog, Christopher; Hultsch, David F; Dixon, Roger A

    2003-05-01

    Data from the Victoria Longitudinal Study were used to examine the 6-year longitudinal stability of personality in older adults. Personality was measured with the NEO Personality Inventory. The longitudinal sample consisted of 223 adults initially ranging from 55 to 85 years of age. Longitudinal confirmatory factor analyses were used to examine the stability of individual differences in change over time, and the stability of the longitudinal factor structure. The results indicated both substantial stability at the level of individual differences in change, as well as significant individual differences in change that were related to age and gender. Finally, the factor structure of personality was invariant over time but did not approximate simple structure for the five dimensions of personality. Our study of 6-year personality development provided both (a). a confirmation of early significant stability findings and (b). unique evidence for significant individual differences in late adulthood.

  11. Why Missing Data Matter in the Longitudinal Study of Adolescent Development: Using the 4-H Study to Understand the Uses of Different Missing Data Methods

    ERIC Educational Resources Information Center

    Jelicic, Helena; Phelps, Erin; Lerner, Richard M.

    2010-01-01

    The study of adolescent development rests on methodologically appropriate collection and interpretation of longitudinal data. While all longitudinal studies of adolescent development involve missing data, the methods to treat missingness that have been recommended most often focus on missing data from cross-sectional studies. The problems of…

  12. Comparisons of IQ in Children With and Without Cochlear Implants: Longitudinal Findings and Associations With Language.

    PubMed

    Cejas, Ivette; Mitchell, Christine M; Hoffman, Michael; Quittner, Alexandra L

    2018-04-05

    To make longitudinal comparisons of intelligence quotient (IQ) in children with cochlear implants (CIs) and typical hearing peers from early in development to the school-age period. Children with additional comorbidities and CIs were also evaluated. To estimate the impact of socioeconomic status and oral language on school-age cognitive performance. This longitudinal study evaluated nonverbal IQ in a multicenter, national sample of 147 children with CIs and 75 typically hearing peers. IQ was evaluated at baseline, prior to cochlear implantation, using the Bayley Scales of Infant and Toddler Development and the Leiter International Performance Scale. School-age IQ was assessed using the Wechsler Intelligence Scales for Children. For the current study, only the Perceptual Reasoning and Processing Speed indices were administered. Oral language was evaluated using the Comprehensive Assessment of Spoken Language. Children in the CI group scored within the normal range of intelligence at both time points. However, children with additional comorbidities scored significantly worse on the Processing Speed, but not the Perceptual Reasoning Index. Maternal education and language were significantly related to school-age IQ in both groups. Importantly, language was the strongest predictor of intellectual functioning in both children with CIs and normal hearing. These results suggest that children using cochlear implants perform similarly to hearing peers on measures of intelligence, but those with severe comorbidities are at-risk for cognitive deficits. Despite the strong link between socioeconomic status and intelligence, this association was no longer significant once spoken language performance was accounted for. These results reveal the important contributions that early intervention programs, which emphasize language and parent training, contribute to cognitive functioning in school-age children with CIs. For families from economically disadvantaged backgrounds, who are at-risk for suboptimal outcomes, these early intervention programs are critical to improve overall functioning.

  13. Temporal associations of popularity and alcohol use among middle school students.

    PubMed

    Tucker, Joan S; Miles, Jeremy N V; D'Amico, Elizabeth J; Zhou, Annie J; Green, Harold D; Shih, Regina A

    2013-01-01

    The goal of this study is to better understand the longitudinal cross-lagged associations between popularity, assessed through self-rating and peer nominations, and alcohol use among middle school students. The analytical sample comprises 1,835 sixth- to eighth-grade students who were initially recruited from three California middle schools and surveyed in the fall and spring semesters of 2 academic years. Students reported on their background characteristics, past-month alcohol use, and perceived popularity. Additionally, students provided school-based friendship nominations, which were used to calculate peer-nominated popularity. A cross-lagged regression approach within a structural equation modeling framework was used to examine the longitudinal relationship between popularity (self-rated and peer-nominated) and alcohol use. There was a statistically significant (p = .024) association between peer-nominated popularity and the probability of alcohol consumption at the subsequent survey, but not vice versa. Our results suggest that in a scenario where 8% of students are past-month drinkers, each increase of five friendship nominations is associated with a 30% greater risk of being a current drinker at the next wave. We found no evidence of longitudinal associations between past-month alcohol consumption and self-rated popularity. Popularity is a risk factor for drinking during the middle school years, with peer-nominated popularity being more predictive of use than self-perceptions of popularity. To inform alcohol prevention efforts for middle school students, additional research is needed to better understand why adolescents with a larger number of school-based friendship ties are more inclined to drink. Copyright © 2013 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  14. Parenting Style and Family Meals: Cross-Sectional and 5-year Longitudinal Associations

    PubMed Central

    Berge, Jerica M.; Wall, Melanie; Neumark-Sztainer, Dianne; Larson, Nicole; Story, Mary

    2010-01-01

    Background Research on family meals in the last decade has shown a positive association between family meal frequency and adolescent healthy dietary intake. However, less is known about factors within the home environment, such as parenting style, which may be associated with family meal patterns. Objective The purpose of this study is to test cross-sectional and five-year longitudinal associations between parenting styles (authoritative, authoritarian, permissive, neglectful) and the frequency of family meals among adolescents. Study Design Data were from Project EAT (Eating Among Teens), a population-based study comprised of youth from diverse ethnic/racial and socioeconomic backgrounds. Two cohorts of adolescents (middle school, high school) completed in-class surveys in 1999 (Time 1) and mailed surveys in 2004 (Time 2). Multiple linear regression models were used to predict mean frequency of family meals at Time 1 and Time 2 from adolescent report of parenting style (both mother and father) at Time 1. Cross-sectional analyses included both adolescent cohorts (n = 4,746) and longitudinal analyses included only the younger cohort (n = 806) because family meal frequency was not assessed in the older cohort at Time 2. Results Cross-sectional results for adolescent girls indicated a positive association between maternal and paternal authoritative parenting style and frequency of family meals. For adolescent boys, maternal authoritative parenting style was associated with more frequent family meals. Longitudinal results indicated that authoritative parenting style predicted higher frequency of family meals five years later, but only between opposite sex parent/adolescent dyads. Conclusions Future research should identify additional factors within the home environment that are associated with family meal frequency in order to develop effective interventions that result in increased family meals for youth. Also, future research should investigate the mealtime behaviors of authoritative parents and identify specific behaviors that dietitians and other health care providers could share with parents of adolescents to help them increase family meal frequency. PMID:20630160

  15. Longitudinal study of self-regulation, positive parenting, and adjustment problems among physically abused children.

    PubMed

    Kim-Spoon, Jungmeen; Haskett, Mary E; Longo, Gregory S; Nice, Rachel

    2012-02-01

    Research using normative and high-risk samples indicates a significant link between problems with self-regulation and child maladjustment. Nevertheless, little is known about the processes that may modify the link between self-regulation and maladjustment. This longitudinal study examined the joint contributions of child self-regulation and positive parenting behaviors to the development of externalizing and internalizing symptomatology spanning from preschool to 1st grade. Data were collected on a total of 95 physically abused children (58% boys); our longitudinal analyses involved 43 children at Time 1 (preschool), 63 children at Time 2 (kindergarten), and 54 children at Time 3 (1st grade). Children's self-regulation was measured by parent report, and their externalizing and internalizing symptomatology was evaluated by teachers. Parents completed self-report measures of positive parenting. Our structural equation modeling analyses revealed positive parenting as a protective factor that attenuated the concurrent association between low self-regulation and externalizing symptomatology among physically abused children. Our findings regarding longitudinal changes in children's externalizing symptomatology supported the differential susceptibility hypothesis: Physically abused children who were at greater risk due to low levels of self-regulation were more susceptible to the beneficial effects of positive parenting, compared to those with high levels of self-regulation. Findings suggest that although physical abuse presents formidable challenges that interfere with the development of adaptive self-regulation, positive parenting behaviors may ameliorate the detrimental effects of maladaptive self-regulation on the development of externalizing symptomatology. In addition, the positive and negative effects of caregiving behaviors were more prominent among physically abused children at great risk due to low self-regulation. Findings from the present study highlight the importance of attending to positive parenting behaviors and child self-regulation when working with physically abused children who are exhibiting externalizing symptomatology. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Longitudinal study of self-regulation, positive parenting, and adjustment problems among physically abused children

    PubMed Central

    Kim, Jungmeen; Haskett, Mary E.; Longo, Gregory S.; Nice, Rachel

    2012-01-01

    Objective Research using normative and high-risk samples indicates a significant link between problems with self-regulation and child maladjustment. Nevertheless, little is known about the processes that may modify the link between self-regulation and maladjustment. This longitudinal study examined the joint contributions of child self-regulation and positive parenting behaviors to the development of externalizing and internalizing symptomatology spanning from preschool to 1st grade. Methods Data were collected on a total of 95 physically abused children (58% boys); our longitudinal analyses involved 43 children at Time 1 (preschool), 63 children at Time 2 (kindergarten), and 54 children at Time 3 (1st grade). Children's self-regulation was measured by parent report, and their externalizing and internalizing symptomatology was evaluated by teachers. Parents completed self-report measures of positive parenting. Results Our structural equation modeling analyses revealed positive parenting as a protective factor that attenuated the concurrent association between low self-regulation and externalizing symptomatology among physically abused children. Our findings regarding longitudinal changes in children's externalizing symptomatology supported the differential susceptibility hypothesis: Physically abused children who were at greater risk due to low levels of self-regulation were more susceptible to the beneficial effects of positive parenting, compared to those with high levels of self-regulation. Conclusions Findings suggest that although physical abuse presents formidable challenges that interfere with the development of adaptive self-regulation, positive parenting behaviors may ameliorate the detrimental effects of maladaptive self-regulation on the development of externalizing symptomatology. In addition, the positive and negative effects of caregiving behaviors were more prominent among physically abused children at great risk due to low self-regulation. Practice Implications Findings from the present study highlight the importance of attending to positive parenting behaviors and child self-regulation when working with physically abused children who are exhibiting externalizing symptomatology. PMID:22398303

  17. Longitudinal construct validity of the minimum data set health status index.

    PubMed

    Jones, Aaron; Feeny, David; Costa, Andrew P

    2018-05-24

    The Minimum Data Set Health Status Index (MDS-HSI) is a generic, preference-based health-related quality of life (HRQOL) measure derived by mapping items from the Resident Assessment Instrument - Minimum Data Set (RAI-MDS) assessment onto the Health Utilities Index Mark 2 classification system. While the validity of the MDS-HSI has been examined in cross-sectional settings, the longitudinal validity has not been explored. The objective of this study was to investigate the longitudinal construct validity of the MDS-HSI in a home care population. This study utilized a retrospective cohort of home care patients in the Hamilton-Niagara-Haldimand-Brant health region of Ontario, Canada with at least two RAI-MDS Home Care assessments between January 2010 and December 2014. Convergent validity was assessed by calculating Spearman rank correlations between the change in MDS-HSI and changes in six validated indices of health domains that can be calculated from the RAI-MDS assessment. Known-groups validity was investigated by fitting multivariable linear regression models to estimate the mean change in MDS-HSI associated with clinically important changes in the six health domain indices and 15 disease symptoms from the RAI-MDS Home Care assessment, controlling for age and sex. The cohort contained 25,182 patients with two RAI-MDS Home Care assessments. Spearman correlations between the MDS-HSI change and changes in the health domain indices were all statistically significant and in the hypothesized small to moderate range [0.1 < ρ < 0.5]. Clinically important changes in all of the health domain indices and 13 of the 15 disease symptoms were significantly associated with clinically important changes in the MDS-HSI. The findings of this study support the longitudinal construct validity of the MDS-HSI in home care populations. In addition to evaluating changes in HRQOL among home care patients in clinical research, economic evaluation, and health technology assessment, the MDS-HSI may be used in system-level applications using routinely collected population-level data.

  18. Reading Fluency from Grade 2-6: A Longitudinal Examination

    ERIC Educational Resources Information Center

    Lipka, Orly

    2017-01-01

    The goal of this study was to examine oral word reading fluency from a developmental perspective in a longitudinal study of students from second grade to sixth grade. The sample consisted of native English speaking students that took part in a large longitudinal study. Participants were assessed on cognitive and literacy measures such as working…

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

    ERIC Educational Resources Information Center

    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…

  20. 77 FR 22068 - Proposed Information Collection (Post-9/11 GI Bill Education Longitudinal Study Survey) Activity...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-12

    ... DEPARTMENT OF VETERANS AFFAIRS [OMB Control No. 2900-New (Post-9/11 GI Bill Longitudinal Study Survey)] Proposed Information Collection (Post-9/11 GI Bill Education Longitudinal Study Survey) Activity... information needed to determine the long-term outcomes of Veterans participating in VBA's Post-9/11GI Bill...

  1. Longitudinal tear of the medial meniscus posterior horn in the anterior cruciate ligament-deficient knee significantly influences anterior stability.

    PubMed

    Ahn, Jin Hwan; Bae, Tae Soo; Kang, Ki-Ser; Kang, Soo Yong; Lee, Sang Hak

    2011-10-01

    Longitudinal tears of the medial meniscus posterior horn (MMPH) are commonly associated with a chronic anterior cruciate ligament (ACL) deficiency. Many studies have demonstrated the importance of the medial meniscus in terms of limiting the amount of anterior-posterior tibial translation in response to anterior tibial loads in ACL-deficient knees. An MMPH tear in an ACL-deficient knee increases the anterior-posterior tibial translation and rotatory instability. In addition, MMPH repair will restore the tibial translation to the level before the tear. Controlled laboratory study. Ten human cadaveric knees were tested sequentially using a custom testing system under 5 conditions: intact, ACL deficient, ACL deficient with an MMPH peripheral longitudinal tear, ACL deficient with an MMPH repair, and ACL deficient with a total medial meniscectomy. The knee kinematics were measured at 0°, 15°, 30°, 60°, and 90° of flexion in response to a 134-N anterior and 200-N axial compressive tibial load. The rotatory kinematics were also measured at 15° and 30° of flexion in a combined rotatory load of 5 N·m of internal tibial torque and 10 N·m of valgus torque. Medial meniscus posterior horn longitudinal tears in ACL-deficient knees resulted in a significant increase in anterior-posterior tibial translation at all flexion angles except 90° (P < .05). An MMPH repair in an ACL-deficient knee showed a significant decrease in anterior-posterior tibial translation at all flexion angles except 60° compared with the ACL-deficient/MMPH tear state (P < .05). The total anterior-posterior translation of the ACL-deficient/MMPH repaired knee was not significantly increased compared with the ACL (only)-deficient knee but was increased compared with the ACL-intact knee (P > .05). A total medial meniscectomy in an ACL-deficient knee did not increase the anterior-posterior tibial translation significantly compared with MMPH tears in ACL-deficient knees at all flexion angles (P > .05). In a combined rotatory load, tibial rotation after MMPH tears or a total medial meniscectomy in an ACL-deficient knee were not affected significantly at all flexion angles. This study shows that an MMPH longitudinal tear in an ACL-deficient knee alters the knee kinematics, particularly the anterior-posterior tibial translation. MMPH repair significantly improved anterior-posterior tibial translation in ACL-deficient knees. These findings may help improve the treatment of patients with ACL and MMPH longitudinal tear by suggesting that the medial meniscal repairs should be performed for greater longevity when combined with an ACL reconstruction.

  2. Investigation of 2-stage meta-analysis methods for joint longitudinal and time-to-event data through simulation and real data application.

    PubMed

    Sudell, Maria; Tudur Smith, Catrin; Gueyffier, François; Kolamunnage-Dona, Ruwanthi

    2018-04-15

    Joint modelling of longitudinal and time-to-event data is often preferred over separate longitudinal or time-to-event analyses as it can account for study dropout, error in longitudinally measured covariates, and correlation between longitudinal and time-to-event outcomes. The joint modelling literature focuses mainly on the analysis of single studies with no methods currently available for the meta-analysis of joint model estimates from multiple studies. We propose a 2-stage method for meta-analysis of joint model estimates. These methods are applied to the INDANA dataset to combine joint model estimates of systolic blood pressure with time to death, time to myocardial infarction, and time to stroke. Results are compared to meta-analyses of separate longitudinal or time-to-event models. A simulation study is conducted to contrast separate versus joint analyses over a range of scenarios. Using the real dataset, similar results were obtained by using the separate and joint analyses. However, the simulation study indicated a benefit of use of joint rather than separate methods in a meta-analytic setting where association exists between the longitudinal and time-to-event outcomes. Where evidence of association between longitudinal and time-to-event outcomes exists, results from joint models over standalone analyses should be pooled in 2-stage meta-analyses. © 2017 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

  3. Strategies for Longitudinal Analysis of the Career Paths of Beginning Teachers: Results from the First through Fourth Waves of the 2007-08 Beginning Teacher Longitudinal Study. Research and Development Report. NCES 2013-336

    ERIC Educational Resources Information Center

    Gray, Lucinda; Brauen, Marsha

    2013-01-01

    To learn more about the early career patterns of beginning teachers, the National Center for Education Statistics (NCES) of the Institute of Education Sciences within the U.S. Department of Education undertook the Beginning Teacher Longitudinal Study (BTLS). The ultimate purpose of this report is to develop a strategy for the longitudinal analysis…

  4. Longitudinal axons are guided by Slit/Robo signals from the floor plate.

    PubMed

    Mastick, Grant S; Farmer, W Todd; Altick, Amy L; Nural, Hikmet Feyza; Dugan, James P; Kidd, Thomas; Charron, Frederic

    2010-01-01

    Longitudinal axons grow long distances along precise pathways to connect major CNS regions. However, during embryonic development, it remains largely undefined how the first longitudinal axons choose specific positions and grow along them. Here, we review recent evidence identifying a critical role for Slit/Robo signals to guide pioneer longitudinal axons in the embryonic brain stem. These studies indicate that Slit/Robo signals from the floor plate have dual functions: to repel longitudinal axons away from the ventral midline, and also to maintain straight longitudinal growth. These dual functions likely cooperate with other guidance cues to establish the major longitudinal tracts in the brain.

  5. High temperature integrated ultrasonic shear and longitudinal wave probes

    NASA Astrophysics Data System (ADS)

    Ono, Y.; Jen, C.-K.; Kobayashi, M.

    2007-02-01

    Integrated ultrasonic shear wave probes have been designed and developed using a mode conversion theory for nondestructive testing and characterization at elevated temperatures. The probes consisted of metallic substrates and high temperature piezoelectric thick (>40μm) films through a paint-on method. Shear waves are generated due to mode conversion from longitudinal to shear waves because of reflection inside the substrate having a specific shape. A novel design scheme is proposed to reduce the machining time of substrates and thick film fabrication difficulty. A probe simultaneously generating and receiving both longitudinal and shear waves is also developed and demonstrated. In addition, a shear wave probe using a clad buffer rod consisting of an aluminum core and stainless steel cladding has been developed. All the probes were tested and successfully operated at 150°C.

  6. Using a Large Scale Computational Model to Study the Effect of Longitudinal and Radial Electrical Coupling in the Cochlea

    NASA Astrophysics Data System (ADS)

    Mistrík, Pavel; Ashmore, Jonathan

    2009-02-01

    We describe a large scale computational model of electrical current flow in the cochlea which is constructed by a flexible Modified Nodal Analysis algorithm to incorporate electrical components representing hair cells and the intercellular radial and longitudinal current flow. The model is used as a laboratory to study the effects of changing longitudinal gap junctional coupling, and shows the way in which cochlear microphonic spreads and tuning is affected. The process for incorporating mechanical longitudinal coupling and feedback is described. We find a difference in tuning and attenuation depending on whether longitudinal or radial couplings are altered.

  7. College Women's Female Friendships: A Longitudinal View

    ERIC Educational Resources Information Center

    Aleman, Ana M. Martinez

    2010-01-01

    This article presents a longitudinal qualitative study of the cognitive value of female friendships formed in college and seeks to appraise the meaning of the phenomenon for the participants. To grasp the temporal effects of the longitudinal data in this study, the author examines and assesses the relevant developmental literature, particularly…

  8. Serious fighting-related injuries produce a significant reduction in intelligence.

    PubMed

    Schwartz, Joseph A; Beaver, Kevin M

    2013-10-01

    Fighting-related injuries are common among adolescents within the United States, but how such injuries relate to subsequent cognitive functioning remains unclear. In particular, the long-term effect of fighting-related injuries suffered during important developmental periods, such as adolescence, on subsequent cognitive functioning has been overlooked by previous studies. The purpose of this study is to examine the association between sustaining serious fighting-related injuries and changes in verbal intelligence (IQ) over a 5- to 6-year time period. Longitudinal multivariate statistical models were used to analyze data from the National Longitudinal Study of Adolescent Health collected between 1994 and 2002 and analyzed in 2013. Even a single fighting-related injury resulted in a significant reduction in IQ over time even after controlling for age, race, sex, and changes in socioeconomic status (SES) over the study period. Additionally, females experienced a significantly greater reduction in IQ from each fighting-related injury than males. Fighting-related injuries have a significant impact on subsequent cognitive functioning and intelligence. The implications for future policies and research are discussed in more detail. Copyright © 2013 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  9. The reciprocal dynamic model of career decision ambiguity tolerance with career indecision: A longitudinal three-wave investigation.

    PubMed

    Xu, Hui; Tracey, Terence J G

    2017-10-01

    The current study investigated the dynamic interplay of career decision ambiguity tolerance and career indecision over 3 assessment times in a sample of college students (n = 583). While the previous research has repeatedly shown an association of career decision ambiguity tolerance with career indecision, the direction of this association has not been adequately assessed with longitudinal investigation. It was hypothesized in this study that there is a reciprocal pattern of career decision ambiguity tolerance leading to subsequent career indecision and career indecision leading to subsequent career decision ambiguity tolerance. Using a cross-lagged panel design, this study found support for the reciprocal pattern that aversion to ambiguity led to increased negative affect and choice anxiety in career decision making, while negative affect and choice anxiety led to increased aversion to ambiguity. Additionally, this study revealed that aversion led to decreased readiness for career decision making and readiness for career decision making led to increased interests in new information. The key findings were discussed with respect to the theoretical and clinical implications for career counseling along with limitations and suggestions for future research. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  10. Attachment styles of nursing students: a cross-sectional and a longitudinal study.

    PubMed

    Kaya, Nurten

    2010-10-01

    This research included two consecutive studies, the first of which aimed to examine university nursing students' attachment styles and to study a set of variables that affect their attachment styles, while the second study aimed to identify the effect of nursing education on nursing students' attachment styles. This research was conducted as a cross-sectional survey with nursing students from a school of nursing in Turkey. The research also included a longitudinal follow-up of first year students, to evaluate the effect of nursing education on attachment styles. Data were collected by using a "Personal Information Form" and "Relationship Scales Questionnaire". Nursing students' personal characteristics of age, longest place of residence, and economic status; family characteristics of number of siblings and families' longest place of residence; and romantic characteristics of any current romantic relationships and the number of past romantic relationships were found to be the factors that were influential in attachment styles. In addition, the nursing students had a statistically significant decrease in their insecure attachment style mean scores at the end of nursing education. Assessing attachment styles may be a potentially useful way to understand and counsel nursing students. Copyright © 2010 Elsevier Ltd. All rights reserved.

  11. Solidarity and ambivalence: comparing two perspectives on intergenerational relations using longitudinal panel data.

    PubMed

    Hogerbrugge, Martijn J A; Komter, Aafke E

    2012-05-01

    Research on family relations has extensively used the intergenerational solidarity model proposed by Bengtson and colleagues. Recently, the relevance of this model for explaining changes in family relations has been questioned, and the concept of intergenerational ambivalence has been proposed as a relevant addition to the model, supposedly acting as a catalyst, and thus serving as an explanation for changes in family relations. This study tests both the viability of the intergenerational solidarity model and the hypothesized effect of ambivalence employing longitudinal data. We use data from 2 waves of the Netherlands' Kinship Panel Study on parent-adult child relationships to estimate latent variable structural equation models. Affection, association, and support between family members are core, mutually reinforcing dimensions of solidarity. The hypothesis that ambivalence is a catalyst for change in family relations was not confirmed. Adding conflict separately revealed that it only affects the core solidarity dimensions but is itself, like normative and structural solidarity, not influenced by them. The relevance of the concept of intergenerational ambivalence for studying changes in family relations can be questioned. The viability of the intergenerational solidarity model is, however, confirmed. The concept of intergenerational ambivalence might be further explored in qualitative studies on family change.

  12. A mechanical property and stress corrosion evaluation of VIM-ESR-VAR work strengthened and direct double aged Inconel 718 bar material

    NASA Technical Reports Server (NTRS)

    Montano, J. W.

    1986-01-01

    Presented are the mechanical properties and the stress corrosion resistance of triple melted vacuum induction melted (VIM), electro-slag remelted (ESR), and vacuum arc remelted (VAR), solution treated, work strengthened and direct double aged Inconel 718 alloy bars 4.00 in. (10.16) and 5.75 in. (14.60 cm) diameter. Tensile, charpy v-notched impact, and compact tension specimens were tested at ambient temperature in both the longitudinal and transverse directions. Longitudinal tensile and yield strengths in excess of 220 ksi (1516.85 MPa) and 200 ksi (1378.00 MPa) respectively, were realized at ambient temperature. Additional charpy impact and compact tension tests were performed at -100 F (-73 C). Longitudinal charpy impact strength equalled or exceeded 12.0 ft-lbs (16.3 Joules) at ambient and at -100 F(-73 C) while longitudinal compact (LC) tension fracture toughness strength remained above 79 ksi (86.80 MPa) at ambient and at -100 F(-73 C) temperatures. No failures occurred in the longitudinal or transverse tensile specimens stressed to 75 and 100 percent of their respective yield strengths and exposed to a salt fog environment for 180 days. Tensile tests performed after the stress corrosion test indicated no mechanical property degradation.

  13. Heat production: Longitudinal versus torsional phacoemulsification.

    PubMed

    Han, Young Keun; Miller, Kevin M

    2009-10-01

    To compare the heat production of longitudinal versus torsional phacoemulsification under strict laboratory test conditions. Department of Ophthalmology, David Geffen School of Medicine at UCLA, and Jules Stein Eye Institute, Los Angeles, California, USA. Two Infiniti phacoemulsification handpieces were inserted into silicone test chambers filled with a balanced salt solution and imaged serially using a thermal camera. Incision compression was simulated by suspending 25.3 g weights from the silicone chambers. To simulate occlusion of the phacoemulsification tip, the aspiration line was clamped. Peak temperatures were measured 0, 10, 30, 60, and 120 seconds after the commencement of continuous ultrasound power. The 2 handpieces, operating exclusively in longitudinal or torsional modes, were compared 3 ways: (1) using the same power displayed on the instrument console, (2) using identical stroke lengths, and (3) using the same applied energy, a product of stroke length and frequency. For all 3 comparisons, torsional phacoemulsification resulted in lower temperatures at each time point. At the same displayed power setting, the scenario most familiar to cataract surgeons, longitudinal phacoemulsification elevated temperatures up to 41.5 degrees C more than torsional phacoemulsification. Torsional phacoemulsification generated less heat than longitudinal phacoemulsification in all 3 comparison tests. Lower operating temperatures indicate lower heat generation within the same volume of fluid, and this may provide additional thermal protection during cataract surgery.

  14. Right ventricular dysfunction affects survival after surgical left ventricular restoration.

    PubMed

    Couperus, Lotte E; Delgado, Victoria; Palmen, Meindert; van Vessem, Marieke E; Braun, Jerry; Fiocco, Marta; Tops, Laurens F; Verwey, Harriëtte F; Klautz, Robert J M; Schalij, Martin J; Beeres, Saskia L M A

    2017-04-01

    Several clinical and left ventricular parameters have been associated with prognosis after surgical left ventricular restoration in patients with ischemic heart failure. The aim of this study was to determine the prognostic value of right ventricular function. A total of 139 patients with ischemic heart failure (62 ± 10 years; 79% were male; left ventricular ejection fraction 27% ± 7%) underwent surgical left ventricular restoration. Biventricular function was assessed with echocardiography before surgery. The independent association between all-cause mortality and right ventricular fractional area change, tricuspid annular plane systolic excursion, and right ventricular longitudinal peak systolic strain was assessed. The additive effect of multiple impaired right ventricular parameters on mortality also was assessed. Baseline right ventricular fractional area change was 42% ± 9%, tricuspid annular plane systolic excursion was 18 ± 3 mm, and right ventricular longitudinal peak systolic strain was -24% ± 7%. Within 30 days after surgery, 15 patients died. Right ventricular fractional area change (hazard ratio, 0.93; 95% confidence interval, 0.88-0.98; P < .01), tricuspid annular plane systolic excursion (hazard ratio, 0.80; 95% confidence interval, 0.66-0.96; P = .02), and right ventricular longitudinal peak systolic strain (hazard ratio, 1.15; 95% confidence interval, 1.05-1.26; P < .01) were independently associated with 30-day mortality, after adjusting for left ventricular ejection fraction and aortic crossclamping time. Right ventricular function was impaired in 21%, 20%, and 27% of patients on the basis of right ventricular fractional area change, tricuspid annular plane systolic excursion, and right ventricular longitudinal peak systolic strain, respectively. Any echocardiographic parameter of right ventricular dysfunction was present in 39% of patients. The coexistence of several impaired right ventricular parameters per patient was independently associated with increased 30-day mortality (hazard ratio, 2.83; 95% confidence interval, 1.64-4.87, P < .01 per additional impaired parameter). Baseline right ventricular systolic dysfunction is independently associated with increased mortality in patients with ischemic heart failure undergoing surgical left ventricular restoration. Copyright © 2016 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

  15. Protecting the underscreened women in developed countries: the value of HPV test.

    PubMed

    Ibáñez, Raquel; Autonell, Josefina; Sardà, Montserrat; Crespo, Nayade; Pique, Pilar; Pascual, Amparo; Martí, Clara; Fibla, Montserrat; Gutiérrez, Cristina; Lloveras, Belén; Moreno-Crespi, Judit; Torrent, Anna; Baixeras, Núria; Alejo, María; Bosch, Francesc Xavier; de Sanjosé, Silvia

    2014-08-08

    Poor attendance to cervical cancer (CC) screening is a major risk factor for CC. Efforts to capture underscreened women are considerable and once women agree to participate, the provision of longitudinal validity of the screening test is of paramount relevance. We evaluate the addition of high risk HPV test (HPV) to cervical cytology as a primary screening test among underscreened women in the longitudinal prediction of intraepithelial lesions grade 2 or worse (CIN2+). Women were included in the study if they were older than 39 years and with no evidence of cervical cytology in the previous five years within the Public Primary Health Care System in Catalonia (Spain). 1,832 underscreened women from eight public primary health areas were identified during 2007-2008 and followed-up for over three years to estimate longitudinal detection of CIN2+. Accuracy of each screening test and the combination of both to detect CIN2+ was estimated. The risk of developing CIN2+ lesions according to histology data by cytology and HPV test results at baseline was estimated using the Kaplan-Meier method. At baseline, 6.7% of participants were HPV positive, 2.2% had an abnormal cytology and 1.3% had both tests positive. At the end of follow-up, 18 out of 767 (2.3%) underscreened women had a CIN2+, two of which were invasive CC. The three-year longitudinal sensitivity and specificity estimates to detect CIN2+ were 90.5% and 93.0% for HPV test and 38.2% and 97.8% for cytology. The negative predictive value was >99.0% for each test. No additional gains in validity parameters of HPV test were observed when adding cytology as co-test. The referral to colposcopy was higher for HPV but generated 53% higher detection of CIN2+ compared to cytology. Underscreened women had high burden of cervical disease. Primary HPV screening followed by cytology triage could be the optimal strategy to identify CIN2+ leading to longer and safe screen intervals.

  16. The tracheal system in post-embryonic development of holometabolous insects: a case study using the mealworm beetle.

    PubMed

    Raś, Marcin; Iwan, Dariusz; Kamiński, Marcin Jan

    2018-06-01

    The tracheal (respiratory) system is regarded as one of the key elements which enabled insects to conquer terrestrial habitats and, as a result, achieve extreme species diversity. Despite this fact, anatomical data concerning this biological system is relatively scarce, especially in an ontogenetic context. The purpose of this study is to provide novel and reliable information on the post-embryonic development of the tracheal system of holometabolous insects using micro-computed tomography methods. Data concerning the structure of the respiratory system acquired from different developmental stages (larvae, pupae and adults) of a single insect species (Tenebrio molitor) are co-analysed in detail. Anatomy of the tracheal system is presented. Sample sizes used (29 individuals) enabled statistical analysis of the results obtained. The following aspects have been investigated (among others): the spiracle arrangement, the number of tracheal ramifications originating from particular spiracles, the diameter of longitudinal trunks, tracheal system volumes, tracheae diameter distribution and fractal dimension analysis. Based on the data acquired, the modularity of the tracheal system is postulated. Using anatomical and functional factors, the following respiratory module types have been distinguished: cephalo-prothoracic, metathoracic and abdominal. These modules can be unambiguously identified in all of the studied developmental stages. A cephalo-prothoracic module aerates organs located in the head capsule, prothorax and additionally prolegs. It is characterised by relatively thick longitudinal trunks and originates in the first thoracic spiracle pair. Thoracic modules support the flight muscles, wings, elytra, meso- and metalegs. The unique feature of this module is the presence of additional longitudinal connections between the neighbouring spiracles. These modules are concentrated around the second prothoracic and the first abdominal spiracle pairs. An abdominal module is characterised by relatively thin ventral longitudinal trunks. Its main role is to support systems located in the abdomen; however, its long visceral tracheae aerate organs situated medially from the flight muscles. Analysis of changes of the tracheal system volume enabled the calculation of growth scaling among body tissues and the volume of the tracheal system. The data presented show that the development of the body volume and tracheal system is not linear in holometabola due to the occurrence of the pupal stage causing a decrease in body volume in the imago and at the same time influencing high growth rates of the tracheal system during metamorphosis, exceeding that ones observed for hemimetabola. © 2018 Anatomical Society.

  17. Lack of association between depression and C-reactive protein level in the baseline of Longitudinal Study of Adult Health (ELSA-Brasil).

    PubMed

    de Menezes, Sara Teles; de Figueiredo, Roberta Carvalho; Goulart, Alessandra Carvalho; Nunes, Maria Angélica; M Benseñor, Isabela; Viana, Maria Carmen; Barreto, Sandhi Maria

    2017-01-15

    Depression has been linked to increased levels of inflammatory markers in clinical studies, but results from general population samples are inconsistent. We aimed to investigate whether depression was associated with serum CRP levels in a cross-sectional analysis of a large cohort from a middle-income country. We analyzed baseline data from 14,821 participants (35-74 years) of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). Current depression (last 7 days) was assessed by the Clinical Interview Schedule-Revised (CIS-R). Because individuals on antidepressants could be negative on CIS-R due to their therapeutic effect, the explanatory variable had three categories: (1) negative on CIS-R and not using antidepressant (reference); (2) negative on CIS-R but using antidepressant; (3) positive on CIS-R with/without antidepressant use. Associations with CRP were investigated by general linear model (GLM). After adjustments for confounders, neither current depression, nor antidepressant use was statistically associated with elevated CRP levels. Additionally, analyzes stratified by gender, type and severity of depression did not change the results. The reference group in our analysis might include participants with a lifetime history of depression. Additionally, the exclusion of questions on weight fluctuation and appetite from the CIS-R applied in ELSA-Brasil may have slightly underestimated the prevalence of depression, as well as limited our ability to assess the presence of somatic symptoms. This study found no association between current depression, use of antidepressants, and serum CRP levels. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. A preliminary study of longitudinal neuroadaptation associated with recovery from addiction.

    PubMed

    Forster, Sarah E; Finn, Peter R; Brown, Joshua W

    2016-11-01

    Few studies have explored longitudinal change in event-related brain responses during early recovery from addiction. Moreover, existing findings yield evidence of both increased and decreased signaling within reward and control centers over time. The current study explored reward- and control-related signals in a risky decision-making task and specifically investigated parametric modulations of the BOLD signal, rather than signal magnitude alone. It was hypothesized that risk-related signals during decision-making and outcome evaluation would reflect recovery and that change in specific signals would correspond with improved treatment outcomes. Twenty-one substance dependent individuals were recruited upon enrollment in community-based substance use treatment programs, wherein they received treatment-as-usual. Participants completed functional neuroimaging assessments at baseline and 3-month follow-up while performing the Balloon Analogue Risk Task (BART). Risk- and reward-sensitive signals were identified using parametric modulators. Substance use was tracked throughout the 3-month study interval using the timeline follow-back procedure. Longitudinal contrasts of parametric modulators suggested improved formation of risk-informed outcome expectations at follow-up. Specifically, a greater response to high risk (low-likelihood) positive feedback was identified in caudal anterior cingulate cortex (ACC) and a greater response to low risk (low-likelihood) negative feedback was identified in caudal ACC and inferior frontal gyrus. In addition, attenuation of a ventromedial prefrontal cortex (vmPFC) "reward-seeking" signal (i.e., increasing response with greater reward) during risky decisions at follow-up was associated with less substance use during the study interval. Changes in risk- and reward-related signaling in ACC/vmPFC appear to reflect recovery and may support sobriety. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  19. Understanding the relationship transitions and associated end of life clinical needs of young adults with life-limiting illnesses: A triangulated longitudinal qualitative study

    PubMed Central

    Johnston, Bridget; Jindal-Snape, Divya; Pringle, Jan; Gold, Libby; Grant, Jayne; Dempsey, Raymond; Scott, Ros; Carragher, Pat

    2016-01-01

    Background: Care of young adults with life-limiting illnesses can often be complex due to the fact that they are growing and developing within the continuing presence of their illness. There is little research conducted nationally and internationally, which has examined the life issues of young adults or taken a longitudinal approach to understand such issues over a period of time. Aim: To gain clear understanding of one particular and pertinent life issue—relationship transition—occurring in the context of being a young adult with a life-limiting illness and the clinical needs arising from this. Design: This was a triangulated, longitudinal, qualitative study involving young adults with life-limiting illnesses and their significant others, namely, family members and healthcare professionals. Semi-structured interviews were conducted with participants and analysed using thematic analysis. Clinical case note reviews were also carried out. Setting/participants: A total of 12 young adults (aged between 17 and 23 years) from 2 hospices and 22 nominated significant others participated in a total of 58 interviews. Results: Thematic analysis revealed 4 main themes and 11 subthemes. The main themes were ‘Dependence dichotomy’, ‘In it together’, ‘Biographical uncertainty’, and ‘Conserving integrity’. These themes helped to establish the nature of relationship transitions that the young adult participants from the study experienced and additionally allowed insight into their possible needs at their end of life. Conclusion: This study has identified the nature of relationship transitions pertinent to young adults and has highlighted associated end of life clinical needs. This study can influence further research into the transitions and end of life needs of this particular patient group receiving palliative care, while informing the lacking evidence base which exists internationally. PMID:27781097

  20. Genetic Variants from Lipid-Related Pathways and Risk for Incident Myocardial Infarction

    PubMed Central

    Song, Ci; Pedersen, Nancy L.; Reynolds, Chandra A.; Sabater-Lleal, Maria; Kanoni, Stavroula; Willenborg, Christina; Syvänen, Ann-Christine; Watkins, Hugh; Hamsten, Anders; Prince, Jonathan A.; Ingelsson, Erik

    2013-01-01

    Background Circulating lipids levels, as well as several familial lipid metabolism disorders, are strongly associated with initiation and progression of atherosclerosis and incidence of myocardial infarction (MI). Objectives We hypothesized that genetic variants associated with circulating lipid levels would also be associated with MI incidence, and have tested this in three independent samples. Setting and Subjects Using age- and sex-adjusted additive genetic models, we analyzed 554 single nucleotide polymorphisms (SNPs) in 41 candidate gene regions proposed to be involved in lipid-related pathways potentially predisposing to incidence of MI in 2,602 participants of the Swedish Twin Register (STR; 57% women). All associations with nominal P<0.01 were further investigated in the Uppsala Longitudinal Study of Adult Men (ULSAM; N = 1,142). Results In the present study, we report associations of lipid-related SNPs with incident MI in two community-based longitudinal studies with in silico replication in a meta-analysis of genome-wide association studies. Overall, there were 9 SNPs in STR with nominal P-value <0.01 that were successfully genotyped in ULSAM. rs4149313 located in ABCA1 was associated with MI incidence in both longitudinal study samples with nominal significance (hazard ratio, 1.36 and 1.40; P-value, 0.004 and 0.015 in STR and ULSAM, respectively). In silico replication supported the association of rs4149313 with coronary artery disease in an independent meta-analysis including 173,975 individuals of European descent from the CARDIoGRAMplusC4D consortium (odds ratio, 1.03; P-value, 0.048). Conclusions rs4149313 is one of the few amino acid changing variants in ABCA1 known to associate with reduced cholesterol efflux. Our results are suggestive of a weak association between this variant and the development of atherosclerosis and MI. PMID:23555974

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