WorldWideScience

Sample records for region-wide longitudinal survey

  1. Rethinking the longitudinal stream temperature paradigm: region-wide comparison of thermal infrared imagery reveals unexpected complexity of river temperatures

    Science.gov (United States)

    We used an extensive dataset of remotely sensed summertime river temperature to compare longitudinal profiles (temperature versus distance) for 54 rivers in the Pacific Northwest. We evaluated (1) how often profiles fit theoretical expectations of asymptotic downstream warming, a...

  2. Total Survey Error for Longitudinal Surveys

    NARCIS (Netherlands)

    Lynn, Peter; Lugtig, P.J.

    2016-01-01

    This article describes the application of the total survey error paradigm to longitudinal surveys. Several aspects of survey error, and of the interactions between different types of error, are distinct in the longitudinal survey context. Furthermore, error trade-off decisions in survey design and

  3. Self-competence in death work among health and social care workers: a region-wide survey in Hong Kong.

    Science.gov (United States)

    Cheung, Johnny T K; Au, Doreen W H; Chan, Wallace C H; Chan, Jenny H Y; Ng, Kenway; Woo, Jean

    2018-04-20

    According to the Quality of Death Index, Hong Kong is lagging behind many other Western and Asian countries in the category of palliative and healthcare. To ensure the provision of high-quality palliative care, it is important to explore the self-competence of health and social care workers in coping with death work including palliative care. This region-wide study aims to assess the level of self-competence with a validated Self-Competence in Death Work Scale (SC-DWS) and examine its correlates. The SC-DWS was administered to a cross-sectional convenience sample of health and social care workers across eight healthcare institutions between January and October 2016. Total scores for the 16-item SC-DWS and its Existential and Emotional subscales were calculated. We then examined sociodemographic variables (e.g., age, profession, place of employment) in relation to the total and subscale scores using multiple linear regression. Coding was conducted on responses to a final open-ended question asking about the personal views of the workers towards their self-competence in death work. We collected data from 885 health and social care workers. Mean score of the SC-DWS was 60.16 (range: 16 - 80), while its Existential and Emotional subscales scored 37.90 (range: 10 - 50) and 14.46 (range: 4 - 20) respectively. Four categories of personal view towards self-competence in death work including (1) personal resources; (2) existential challenges and coping; (3) emotional challenges and coping; and (4) personal recommendations on improving self-competence were identified. In multivariate analyses, workers aged 50 or above, divorced, working in Hospice A, Rehabilitation Hospital B (where a quality improvement initiative in end-of-life care was implemented) and Acute Hospital B (a Christian institution with strong caring culture) and with personal bereavement experience had significantly higher scores, whereas nurses scored significantly lower than less-educated personal care

  4. Variable selection and estimation for longitudinal survey data

    KAUST Repository

    Wang, Li; Wang, Suojin; Wang, Guannan

    2014-01-01

    There is wide interest in studying longitudinal surveys where sample subjects are observed successively over time. Longitudinal surveys have been used in many areas today, for example, in the health and social sciences, to explore relationships

  5. Variable selection and estimation for longitudinal survey data

    KAUST Repository

    Wang, Li

    2014-09-01

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

  6. Immigrants' language skills: the immigrant experience in a longitudinal survey

    OpenAIRE

    Barry CHISWICK; Yew LEE; Paul W. MILLER

    2003-01-01

    This paper is concerned with the determinants of English language proficiency among immigrants. It presents a model based on economic incentives, exposure, and efficiency in language acquisition, which it tests using the Longitudinal Survey of Immigrants to Australia. Probit and bivariate probit analyses are employed. The hypotheses are supported by the data. The bivariate probit analysis across waves indicates a "regression to the mean" in the unobserved components of English language profic...

  7. Dead or Alive? Dealing with Unknown Eligibility in Longitudinal Surveys

    Directory of Open Access Journals (Sweden)

    Watson Nicole

    2016-12-01

    Full Text Available Longitudinal surveys follow people over time and some of these people will die during the life of the panel. Through fieldwork effort, some deaths will be reported or known, but others will be unobserved due to sample members no longer being issued to field or having inconclusive fieldwork outcomes (such as a noncontact that is not followed by a contact at a later wave. The coverage of deaths identified among sample members has flow-on implications to nonresponse correction. Using the Household, Income and Labour Dynamics in Australia (HILDA Survey, four methods are used to examine the extent of missing death reports. The first method matches the sample to the national death register. The second method uses life-expectancy tables to extrapolate the expected number of deaths among the sample with unknown eligibility. The third method is similar but models deaths from data internal to the survey. The fourth method models deaths as part of the attrition process of a longitudinal survey. The last three methods are compared to the first method and the implications for the construction of balanced panel weights and subsequent population inference are explored.

  8. Longitudinal Surveys of Australian Youth (LSAY): 2006 Cohort Wave 4 (2009)--Questionnaire. Technical Report 56A

    Science.gov (United States)

    National Centre for Vocational Education Research (NCVER), 2010

    2010-01-01

    The Longitudinal Surveys of Australian Youth (LSAY) program studies the progress of several groups of young Australians as they move from school into post-secondary education and work. This technical paper contains the questionnaire for the LSAY 2006 cohort Wave 4 (2009) data set. [For the "Longitudinal Surveys of Australian Youth (LSAY):…

  9. 2012 School Libraries Count! National Longitudinal Survey of School Library Programs

    Science.gov (United States)

    American Association of School Librarians (NJ1), 2012

    2012-01-01

    AASL's School Libraries Count! annual longitudinal survey is an online survey that is open to all primary and secondary school library programs to participate. The 2012 survey was launched on January 24th and closed on March 20th. The survey was publicized through various professional organizations and events and through word of mouth. Data…

  10. Training, Innovation and Business Performance: An Analysis of the Business Longitudinal Survey.

    Science.gov (United States)

    Dockery, A. Michael

    This paper uses the Australian Bureau of Statistics' Business Longitudinal Survey to explore relationships between training, innovation, and firm performance for Australian businesses with less than 200 employees. The longitudinal nature of the data is used to test various hypotheses about the nature of the link between training, business changes,…

  11. Longitudinal Surveys of Australian Youth (LSAY) 1998 Cohort: Wave 12 (2009)--Questionnaire. Technical Report 58A

    Science.gov (United States)

    National Centre for Vocational Education Research (NCVER), 2010

    2010-01-01

    The Longitudinal Surveys of Australian Youth (LSAY) program studies the progress of several groups of young Australians as they move from school into post-secondary education and work. This technical paper contains the questionnaire for the LSAY 1998 cohort Wave 12 (2009) data set. [For the accompanying frequency tables, "Longitudinal Surveys…

  12. Advantages and disadvantages : longitudinal vs. repeated cross-section surveys

    Science.gov (United States)

    1996-06-20

    The benefits of a longitudinal analysis over a repeated cross-sectional study include increased statistical power and the capability to estimate a greater range of conditional probabilities. With the Puget Sound Transportation Panel (PSTP), and any s...

  13. Tropical cyclone cooling combats region-wide coral bleaching.

    Science.gov (United States)

    Carrigan, Adam D; Puotinen, Marji

    2014-05-01

    Coral bleaching has become more frequent and widespread as a result of rising sea surface temperature (SST). During a regional scale SST anomaly, reef exposure to thermal stress is patchy in part due to physical factors that reduce SST to provide thermal refuge. Tropical cyclones (TCs - hurricanes, typhoons) can induce temperature drops at spatial scales comparable to that of the SST anomaly itself. Such cyclone cooling can mitigate bleaching across broad areas when well-timed and appropriately located, yet the spatial and temporal prevalence of this phenomenon has not been quantified. Here, satellite SST and historical TC data are used to reconstruct cool wakes (n=46) across the Caribbean during two active TC seasons (2005 and 2010) where high thermal stress was widespread. Upon comparison of these datasets with thermal stress data from Coral Reef Watch and published accounts of bleaching, it is evident that TC cooling reduced thermal stress at a region-wide scale. The results show that during a mass bleaching event, TC cooling reduced thermal stress below critical levels to potentially mitigate bleaching at some reefs, and interrupted natural warming cycles to slow the build-up of thermal stress at others. Furthermore, reconstructed TC wave damage zones suggest that it was rare for more reef area to be damaged by waves than was cooled (only 12% of TCs). Extending the time series back to 1985 (n = 314), we estimate that for the recent period of enhanced TC activity (1995-2010), the annual probability that cooling and thermal stress co-occur is as high as 31% at some reefs. Quantifying such probabilities across the other tropical regions where both coral reefs and TCs exist is vital for improving our understanding of how reef exposure to rising SSTs may vary, and contributes to a basis for targeting reef conservation. © 2014 John Wiley & Sons Ltd.

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

    OpenAIRE

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

    2013-01-01

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

  15. Birth order and paediatric allergic disease: A nationwide longitudinal survey.

    Science.gov (United States)

    Kikkawa, T; Yorifuji, T; Fujii, Y; Yashiro, M; Okada, A; Ikeda, M; Doi, H; Tsukahara, H

    2018-05-01

    Environmental factors seem to be related to the incidence of allergic disease. Children with a later birth order are often exposed to environments, where pathogens and endotoxins can be found, and thus have a higher risk of developing infectious diseases. Therefore, birth order is regarded as an indicator that reflects post-natal environment. However, longitudinal studies are limited on this subject. This study sought to elucidate the relationships between birth order and allergic disease. From a nationwide longitudinal study that followed children born in 2001 (n = 47 015), we selected doctors' visits for 3 types of allergic disease-bronchial asthma, food allergy and atopic dermatitis-from infancy to 12 years of age and conducted binomial log-linear regression analysis to evaluate the associations between birth order and these diseases. We adjusted for the child and parental factors and estimated risk ratio (RR) and 95% confidence interval (CI) for each outcome. The associations between birth order and bronchial asthma were diverse; later birth order increased the risk in early childhood, but decreased the risks during school age. For example, the adjusted RR comparing third-born or higher and first-born children was 1.19 (95% CI, 1.05-1.35) between 30 and 42 months of age, but was 0.76 (95% CI, 0.65-0.89) between 10 and 11 years. Later birth order was generally protective for food allergy but increased the risk of atopic dermatitis. The influence of birth order depended on the type of allergic disease and the childhood period. Childhood is unique in terms of physical and immunological development, and the immune response to the post-natal environment in childhood appears to be heterogeneous. © 2018 John Wiley & Sons Ltd.

  16. Longitudinal Surveys of Australian Youth (LSAY): 1995 Cohort Derived Variables. Technical Report 69

    Science.gov (United States)

    National Centre for Vocational Education Research (NCVER), 2012

    2012-01-01

    This technical report details the derived variables developed for users of the Longitudinal Surveys of Australian Youth (LSAY) data. The derived variables fall into the categories education, employment and social, and help to simplify the complexity of the LSAY data by providing useful indicators for analysis. To help LSAY data users understand…

  17. Longitudinal Surveys of Australian Youth (LSAY): Derived Variables. Technical Report 64

    Science.gov (United States)

    National Centre for Vocational Education Research (NCVER), 2012

    2012-01-01

    This technical report describes the 24 derived variables developed for users of the Longitudinal Surveys of Australian Youth (LSAY) data. The variables fall into the categories education, employment and social, and help to simplify the complexity of the LSAY data by providing useful indicators for analysis. To help LSAY data users understand and…

  18. Longitudinal Surveys of Australian Youth (LSAY): 1995 Cohort: User Guide. Technical Report 49

    Science.gov (United States)

    National Centre for Vocational Education Research (NCVER), 2009

    2009-01-01

    The Longitudinal Surveys of Australian Youth (LSAY) is a research program that tracks young people as they move from school into further study, work and other destinations. It uses large, nationally representative samples of young people to collect information about education and training, work, and social development. It includes surveys…

  19. Longitudinal Surveys of Australian Youth (LSAY) 2006 Cohort: Wave 6 (2011)--Questionnaire. Technical Report 75A

    Science.gov (United States)

    National Centre for Vocational Education Research (NCVER), 2012

    2012-01-01

    The Longitudinal Surveys of Australian Youth (LSAY) program studies the progress of several groups of young Australians as they move from school into post-secondary education and work. This series of documents provides supporting information for the LSAY data set of the 2006 cohort at wave 6 (2011). The document presents the questionnaire for LSAY…

  20. Longitudinal Surveys of Australian Youth (LSAY) 2009 Cohort: Wave 1 (2009)--Frequency Tables. Technical Report 70

    Science.gov (United States)

    National Centre for Vocational Education Research (NCVER), 2012

    2012-01-01

    The Longitudinal Surveys of Australian Youth (LSAY) program studies the progress of several groups of young Australians as they move from school into post-secondary education and work. Since 2003, the LSAY program has been integrated with the Programme for International Student Assessment (PISA) conducted by the Organisation for Economic…

  1. Longitudinal Surveys of Australian Youth (LSAY): 2006 Cohort Wave 4 (2009)--Frequency Tables. Technical Report 56B

    Science.gov (United States)

    National Centre for Vocational Education Research (NCVER), 2010

    2010-01-01

    The Longitudinal Surveys of Australian Youth (LSAY) program studies the progress of several groups of young Australians as they move from school into post-secondary education and work. This technical paper contains the frequency tables for the LSAY 2006 cohort Wave 4 (2009) data set. [For the "Longitudinal Surveys of Australian Youth (LSAY):…

  2. SDQ and quasi-SDQ for children in the Danish Longitudinal Survey of Children (DALSC)

    DEFF Research Database (Denmark)

    Rosenstjerne Andersen, Angelo; Deding, Mette; Lausten, Mette

    Using data from the first three waves of the Danish Longitudinal Survey of Children (DLSC), this working paper develops measures of child well-being with the aim of allowing comparisons in time. These measures are inspired by the SDQ-index[1] (from the Strengths and Difficulties Questionnaire......), a relatively easy-to-use index enabling a grouping of children into three groups – normal, borderline, and abnormal – according to levels of psycho-social problems. The SDQ-questions were part of the third wave of the DLSC-survey in 2003 and will continue to be so in the future. The first two waves of the DLSC...

  3. Longitudinal Surveys of Australian Youth (LSAY) 1998 Cohort: Wave 12 (2009)--Frequency Tables. Technical Report 58B

    Science.gov (United States)

    National Centre for Vocational Education Research (NCVER), 2010

    2010-01-01

    The Longitudinal Surveys of Australian Youth (LSAY) program studies the progress of several groups of young Australians as they move from school into post-secondary education and work. This technical paper contains the frequency tables for the LSAY 1998 cohort Wave 12 (2009) data set. [For the accompanying questionnaire, "Longitudinal Surveys…

  4. Attitude changes toward nuclear power generation. Analysis of data from a longitudinal survey

    International Nuclear Information System (INIS)

    Matsuda, Toshihiro

    1998-01-01

    The Attitude changes toward nuclear power generation in response to incidents/accidents at the nuclear facilities were examined, using a longitudinal survey. A replicated survey was conducted in Kansai area following the incidents in 1995 and 1997, and a panel survey was conducted in 1997, using the same subjects as those in the survey conducted by C. Hayashi in 1993 about the attitude toward nuclear power generation. The results of the panel survey showed that an anxiety about a nuclear incident/accident tended to increase and that the number of those who decreased an anxiety about a nuclear incident/accident was relatively small, compared to an anxiety about other incidents/accidents. Using the quantification theory to analyze the group that showed changes in attitude toward nuclear power generation, it was suggested that the increase or decrease in the level of anxiety about a nuclear power incident/accident had an influence on the changes in attitude. However, the influence was not the most significant one compared to other factors. With the inclusion of the group that showed no change in attitude, the general population structure that the approval for nuclear power generation because of inevitable use of nuclear energy accounted for sixty percent remained with no significant change. (author)

  5. Internet and telephonic IVR mixed-mode survey for longitudinal studies: choice, retention, and data equivalency.

    Science.gov (United States)

    Verma, Santosh K; Courtney, Theodore K; Lombardi, David A; Chang, Wen-Ruey; Huang, Yueng-Hsiang; Brennan, Melanye J; Perry, Melissa J

    2014-01-01

    This study examined data equivalency and loss to follow-up rates from Internet and interactive voice response (IVR) system surveys in a prospective-cohort study. 475 limited-service restaurant workers participating in the 12-week study were given a choice to report their weekly slipping experience by either IVR or Internet. Demographic differences, loss to follow-up, self-reported rates of slipping, and selection of first and last choices were compared. Loss to follow-up rates were slightly higher for those choosing the IVR mode. Rates of slipping and selection of first and last choices were not significantly different between survey modes. Propensity to choose an Internet survey decreased with increasing age, and was the lowest among Spanish speakers (5%) and those with less than a high school education (14%). Studies relying solely on Internet-based data collection may lead to selective exclusion of certain populations. Findings suggest that Internet and IVR may be combined as survey modalities within longitudinal studies. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  6. [A longitudinal entomologic survey on the transmission of malaria in Ouagadougou (Burkina Faso)].

    Science.gov (United States)

    Rossi, P; Belli, A; Mancini, L; Sabatinelli, G

    1986-04-01

    A longitudinal entomological malaria survey was carried out in five zones of the town of Ouagadougou, Burkina Faso, and in three neighbouring villages. The main vector is Anopheles gambiae s.l. with An. funestus having a role in some localities during the dry season. Pyrethrum spray catches were carried out once or twice per month to determine variations in vector density. Inoculation rates were estimated from the number of blood-fed vectors per man and from the sporozoite rates. Larval sampling was routinely carried out all over the urban area in order to map the larval breeding sites. Widely different degrees of malaria transmission were documented in the urban area mainly related to the spatial and temporal distribution of An. gambiae larval breeding sites. Higher inoculation rates, depending both on higher vector densities and sporozoite rates, were documented in the villages.

  7. Self-rated health in Canadian immigrants: analysis of the Longitudinal Survey of Immigrants to Canada.

    Science.gov (United States)

    Setia, Maninder Singh; Lynch, John; Abrahamowicz, Michal; Tousignant, Pierre; Quesnel-Vallee, Amelie

    2011-03-01

    Using a multi-level random effects logistic model, we examine the contribution of source country, individual characteristics and post-migration experiences to the self-rated health (SRH) of 2468 male and 2614 female immigrants from the Longitudinal Survey of Immigrants to Canada (2001-2005). Sex/gender differences were found for all categories of health determinants. Source country characteristics explained away some ethnic differentials in health and had independent negative effects, particularly among women. Thus, women from countries lower on the development index appear at greater risk of poor SRH, and should be at the forefront of public health programmes aimed at new immigrants in Canada. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Longitudinal Surveys of Australian Youth (LSAY) 2009 Cohort: Wave 2 (2010)--Frequency Tables. Technical Report 71B

    Science.gov (United States)

    National Centre for Vocational Education Research (NCVER), 2012

    2012-01-01

    The Longitudinal Surveys of Australian Youth (LSAY) program studies the progress of several groups of young Australians as they move from school into post-secondary education and work. This technical paper contains the frequency tables for the LSAY 2009 cohort Wave 2 (2010) data set.

  9. Body Size at Birth, Physical Development and Cognitive Outcomes in Early Childhood: Evidence from the Longitudinal Survey of Australian Children

    Science.gov (United States)

    Ulker, Aydogan

    2016-01-01

    Using a rich sample created from the Longitudinal Survey of Australian Children, we investigate the extent to which the relationship between body size at birth and early childhood cognitive skills is mediated by physical development indicators. Consistent with existing evidence from other countries, we find a significant relationship between body…

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

    Science.gov (United States)

    National Centre for Vocational Education Research (NCVER), 2009

    2009-01-01

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

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

    Science.gov (United States)

    National Centre for Vocational Education Research (NCVER), 2009

    2009-01-01

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

  12. Longitudinal Surveys of Australian Youth (LSAY) 2006 Cohort: Wave 6 (2011)--Frequency Tables. Technical Report 75B

    Science.gov (United States)

    National Centre for Vocational Education Research (NCVER), 2012

    2012-01-01

    The Longitudinal Surveys of Australian Youth (LSAY) program studies the progress of several groups of young Australians as they move from school into post-secondary education and work. This series of documents provides supporting information for the LSAY data set of the 2006 cohort at wave 6 (2011). This document presents the frequency tables for…

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

    Science.gov (United States)

    National Centre for Vocational Education Research (NCVER), 2012

    2012-01-01

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

  14. Research on the Danish Longitudinal Survey of Children (DALSC) at the Danish National Centre for Social Research

    DEFF Research Database (Denmark)

    Ottosen, Mai Heide

    2011-01-01

    This article reviews research results obtained using the Danish Longitudinal Survey of Children born in 1995 (DALSC), which is placed at SFI, the Danish National Centre for Social Research. DALSC aims to gain insight into children’s growing-up conditions in contemporary society. DALSC consists of...

  15. Longitudinal prediction of sexually transmitted diseases among adolescents: results from a national survey.

    Science.gov (United States)

    Crosby, R; Leichliter, J S; Brackbill, R

    2000-05-01

    Although adolescent use of condoms has been increasing, incidence of sexually transmitted diseases (STDs) among young people remains high. To identify adolescent behavioral risk factors for acquiring STDs, this study assessed adolescent self-reports of acquired chlamydia, gonorrhea, syphilis, and trichomoniasis within 1 year after a baseline interview. We used data from the National Longitudinal Survey of Adolescent Health for this study. Data were collected in the homes of survey respondents, using audio-computer-assisted self-interview (audio-CASI) technology and interviews. Participants were enrolled in grades 7-11 from 134 U.S. schools. A cohort of 4593 sexually experienced adolescents was followed for 1 year. We conducted separate analyses for both genders. About 3.1% of the male adolescents and nearly 4.7% of the female adolescents reported having had at least one STD after the baseline interview. For both genders, self-reported STD infection before baseline interview was the best predictor of self-reported STD infection 1 year after baseline interview. Female adolescents were more likely to report diagnosis with an STD after baseline if they self-identified as a minority race (other than Asian) and perceived that their mother did not disapprove of their having sex. Female adolescents were less likely to report STDs if they perceived that adults care about them. No additional variables predicted STD diagnosis after baseline for male adolescents. We conclude that past history of STD infection is the most important indicator of subsequent STD infection among adolescents. Thus, this study suggests the benefit of specific clinical efforts designed to promote preventive behavior among adolescents newly diagnosed with an STD.

  16. Recruiting online: lessons from a longitudinal survey of contraception and pregnancy intentions of young Australian women.

    Science.gov (United States)

    Harris, Melissa L; Loxton, Deborah; Wigginton, Britta; Lucke, Jayne C

    2015-05-15

    Recruitment of young people for epidemiologic research remains challenging, with marked decreases in the effectiveness of face-to-face, mail, and telephone recruitment methods. We report on the implementation and feasibility of an innovative and flexible approach used to recruit participants for a longitudinal cohort study about contraceptive use and pregnancy (the Contraceptive Use, Pregnancy Intention, and Decisions (CUPID) Study). Australian women aged 18-23 years were recruited using a range of online, networking, and offline methods, including social media (primarily Facebook (Facebook Inc., Menlo Park, California; http://www.facebook.com)), face-to-face events, distribution of promotional material, and media releases. Over the course of the 1-year recruitment period (beginning in September 2012), a total of 3,795 eligible women were recruited to complete the online survey, at a cost of approximately A$11 per participant. This sample was found to be broadly representative of the Australian population of women aged 18-23 years in terms of demographic characteristics, with the exception of an overrepresentation of tertiary-educated women (88.7% compared with 72.6%). This study demonstrated that although current recruitment strategies are required to be innovative and flexible in order to engage young people in epidemiologic research, representative samples can be achieved online at reasonable cost. © The Author 2015. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. The deterioration of Canadian immigrants' oral health: analysis of the Longitudinal Survey of Immigrants to Canada.

    Science.gov (United States)

    Calvasina, Paola; Muntaner, Carles; Quiñonez, Carlos

    2015-10-01

    To examine the effect of immigration on the self-reported oral health of immigrants to Canada over a 4-year period. The study used Statistics Canada's Longitudinal Survey of Immigrants to Canada (LSIC 2001-2005). The target population comprised 3976 non-refugee immigrants to Canada. The dependent variable was self-reported dental problems. The independent variables were as follows: age, sex, ethnicity, income, education, perceived discrimination, history of social assistance, social support, and official language proficiency. A generalized estimation equation approach was used to assess the association between dependent and independent variables. After 2 years, the proportion of immigrants reporting dental problems more than tripled (32.6%) and remained approximately the same at 4 years after immigrating (33.3%). Over time, immigrants were more likely to report dental problems (OR = 2.77; 95% CI 2.55-3.02). An increase in self-reported dental problems over time was associated with sex, history of social assistance, total household income, and self-perceived discrimination. An increased likelihood of reporting dental problems occurred over time. Immigrants should arguably constitute an important focus of public policy and programmes aimed at improving their oral health and access to dental care in Canada. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. A longitudinal genetic survey identifies temporal shifts in the population structure of Dutch house sparrows

    Science.gov (United States)

    Cousseau, L; Husemann, M; Foppen, R; Vangestel, C; Lens, L

    2016-01-01

    Dutch house sparrow (Passer domesticus) densities dropped by nearly 50% since the early 1980s, and similar collapses in population sizes have been reported across Europe. Whether, and to what extent, such relatively recent demographic changes are accompanied by concomitant shifts in the genetic population structure of this species needs further investigation. Therefore, we here explore temporal shifts in genetic diversity, genetic structure and effective sizes of seven Dutch house sparrow populations. To allow the most powerful statistical inference, historical populations were resampled at identical locations and each individual bird was genotyped using nine polymorphic microsatellites. Although the demographic history was not reflected by a reduction in genetic diversity, levels of genetic differentiation increased over time, and the original, panmictic population (inferred from the museum samples) diverged into two distinct genetic clusters. Reductions in census size were supported by a substantial reduction in effective population size, although to a smaller extent. As most studies of contemporary house sparrow populations have been unable to identify genetic signatures of recent population declines, results of this study underpin the importance of longitudinal genetic surveys to unravel cryptic genetic patterns. PMID:27273323

  19. A structural equation model of turnover for a longitudinal survey among early career registered nurses.

    Science.gov (United States)

    Brewer, Carol S; Chao, Ying-Yu; Colder, Craig R; Kovner, Christine T; Chacko, Thomas P

    2015-11-01

    Key predictors of early career nurses' turnover are job satisfaction, organizational commitment, job search, intent to stay, and shock (back injuries) based on the literature review and our previous research. Existing research has often omitted one of these key predictors. The purpose of this study in a sample of early career nurses was to compare predictors of turnover to nurses' actual turnover at two time points in their careers. A multi-state longitudinal panel survey of early career nurses was used to compare a turnover model across two time periods. The sample has been surveyed five times. The sample was selected using a two-stage sample of registered nurses nested in 51 metropolitan areas and nine non-metropolitan, rural areas in 34 states and the District of Columbia. The associations between key predictors of turnover were tested using structural equation modeling and data from the earliest and latest panels in our study. We used predictors from the respondents who replied to the Wave-1 survey in 2006 and their turnover status from Wave 2 in 2007 (N=2386). We compared these results to the remaining respondents' predictors from Wave 4 in 2011 and their turnover status in Wave 5 in 2013 (N=1073). We tested and found no effect for missingness from Wave 1-5 and little evidence of attrition bias. Strong support was found for the relationships hypothesized among job satisfaction, organizational commitment, intent to stay, and turnover, with some support for shock and search in the Wave 1-2 sample. However, for Wave 4-5 sample (n=1073), none of the paths through search were significant, nor was the path from shock to turnover. Nurses in the second analysis who had matured longer in their career did not have a significant response to search or shock (back injuries), which may indicate how easily experienced registered nurses find new jobs and/or accommodation to jobs requiring significant physicality. Nurse turnover is a major concern for healthcare organizations

  20. Longitudinal Trends in Fall Accidents in Community Dwelling Korean Adults: The 2008?2013 Korean Community Health Survey

    OpenAIRE

    Hong, Ickpyo; Simpson, Annie N.; Logan, Sarah; Woo, Hee-Soon

    2016-01-01

    Objective To describe the longitudinal characteristics of unintentional fall accidents using a representative population-based sample of Korean adults. Methods We examined data from the Korean Community Health Survey from 2008 to 2013. Univariate analysis and multivariable logistic regression were used to identify the characteristics of fall accidents in adults. Results Between 2008 and 2013, the incidence rate of fall accidents requiring medical treatment increased from 1,248 to 3,423 per 10...

  1. Is poor mental health a risk factor for retirement? Findings from a longitudinal population survey.

    Science.gov (United States)

    Olesen, Sarah C; Butterworth, Peter; Rodgers, Bryan

    2012-05-01

    Poor mental health may influence people's decisions about, and ability to, keep working into later adulthood. The identification of factors that drive retirement provides valuable information for policymakers attempting to mitigate the effects of population ageing. This study examined whether mental health predicts subsequent retirement in a general population sample, and whether this association varied with the timing of retirement. Longitudinal data from 2,803 people aged 45-75 years were drawn from five waves of the Household Income and Labour Dynamics in Australia (HILDA) survey. Discrete-time survival analyses were used to estimate the association between mental health and retirement. Mental health was measured using the Mental Health Index (MHI-5). The relative influences of other health, social, financial, and work-related predictors of retirement were considered to determine the unique contribution of mental health to retirement behaviour. Poor mental health was associated with higher rates of retirement in men (hazard rate ratio, HRR 1.19, 95% CI 1.01-1.29), and workforce exit more generally in women (HRR 1.14, 95% CI 1.07-1.22). These associations varied with the timing of retirement and were driven by early retirees specifically. Physical functioning, income, social activity, job conditions (including job stress for women and job control for men), and aspects of job satisfaction also predicted subsequent retirement. Poor mental and physical health predict workforce departure in mid-to-late adulthood, particularly early retirement. Strategies to accommodate health conditions in the workplace may reduce rates of early retirement and encourage people to remain at work into later adulthood.

  2. Factor structure and longitudinal measurement invariance of the demand control support model: an evidence from the Swedish Longitudinal Occupational Survey of Health (SLOSH).

    Science.gov (United States)

    Chungkham, Holendro Singh; Ingre, Michael; Karasek, Robert; Westerlund, Hugo; Theorell, Töres

    2013-01-01

    To examine the factor structure and to evaluate the longitudinal measurement invariance of the demand-control-support questionnaire (DCSQ), using the Swedish Longitudinal Occupational Survey of Health (SLOSH). A confirmatory factor analysis (CFA) and multi-group confirmatory factor analysis (MGCFA) models within the framework of structural equation modeling (SEM) have been used to examine the factor structure and invariance across time. Four factors: psychological demand, skill discretion, decision authority and social support, were confirmed by CFA at baseline, with the best fit obtained by removing the item repetitive work of skill discretion. A measurement error correlation (0.42) between work fast and work intensively for psychological demands was also detected. Acceptable composite reliability measures were obtained except for skill discretion (0.68). The invariance of the same factor structure was established, but caution in comparing mean levels of factors over time is warranted as lack of intercept invariance was evident. However, partial intercept invariance was established for work intensively. Our findings indicate that skill discretion and decision authority represent two distinct constructs in the retained model. However removing the item repetitive work along with either work fast or work intensively would improve model fit. Care should also be taken while making comparisons in the constructs across time. Further research should investigate invariance across occupations or socio-economic classes.

  3. Factor structure and longitudinal measurement invariance of the demand control support model: an evidence from the Swedish Longitudinal Occupational Survey of Health (SLOSH.

    Directory of Open Access Journals (Sweden)

    Holendro Singh Chungkham

    Full Text Available OBJECTIVES: To examine the factor structure and to evaluate the longitudinal measurement invariance of the demand-control-support questionnaire (DCSQ, using the Swedish Longitudinal Occupational Survey of Health (SLOSH. METHODS: A confirmatory factor analysis (CFA and multi-group confirmatory factor analysis (MGCFA models within the framework of structural equation modeling (SEM have been used to examine the factor structure and invariance across time. RESULTS: Four factors: psychological demand, skill discretion, decision authority and social support, were confirmed by CFA at baseline, with the best fit obtained by removing the item repetitive work of skill discretion. A measurement error correlation (0.42 between work fast and work intensively for psychological demands was also detected. Acceptable composite reliability measures were obtained except for skill discretion (0.68. The invariance of the same factor structure was established, but caution in comparing mean levels of factors over time is warranted as lack of intercept invariance was evident. However, partial intercept invariance was established for work intensively. CONCLUSION: Our findings indicate that skill discretion and decision authority represent two distinct constructs in the retained model. However removing the item repetitive work along with either work fast or work intensively would improve model fit. Care should also be taken while making comparisons in the constructs across time. Further research should investigate invariance across occupations or socio-economic classes.

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Science.gov (United States)

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

    2015-05-04

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

  6. The effectiveness of a monetary incentive offer on survey response rates and response completeness in a longitudinal study.

    Science.gov (United States)

    Yu, Shengchao; Alper, Howard E; Nguyen, Angela-Maithy; Brackbill, Robert M; Turner, Lennon; Walker, Deborah J; Maslow, Carey B; Zweig, Kimberly C

    2017-04-26

    Achieving adequate response rates is an ongoing challenge for longitudinal studies. The World Trade Center Health Registry is a longitudinal health study that periodically surveys a cohort of ~71,000 people exposed to the 9/11 terrorist attacks in New York City. Since Wave 1, the Registry has conducted three follow-up surveys (Waves 2-4) every 3-4 years and utilized various strategies to increase survey participation. A promised monetary incentive was offered for the first time to survey non-respondents in the recent Wave 4 survey, conducted 13-14 years after 9/11. We evaluated the effectiveness of a monetary incentive in improving the response rate five months after survey launch, and assessed whether or not response completeness was compromised due to incentive use. The study compared the likelihood of returning a survey for those who received an incentive offer to those who did not, using logistic regression models. Among those who returned surveys, we also examined whether those receiving an incentive notification had higher rate of response completeness than those who did not, using negative binomial regression models and logistic regression models. We found that a $10 monetary incentive offer was effective in increasing Wave 4 response rates. Specifically, the $10 incentive offer was useful in encouraging initially reluctant participants to respond to the survey. The likelihood of returning a survey increased by 30% for those who received an incentive offer (AOR = 1.3, 95% CI: 1.1, 1.4), and the incentive increased the number of returned surveys by 18%. Moreover, our results did not reveal any significant differences on response completeness between those who received an incentive offer and those who did not. In the face of the growing challenge of maintaining a high response rate for the World Trade Center Health Registry follow-up surveys, this study showed the value of offering a monetary incentive as an additional refusal conversion strategy. Our

  7. Individual quality of life in patients undergoing radiotherapy. A longitudinal survey

    International Nuclear Information System (INIS)

    Wenskus, Julia Katharina

    2015-01-01

    The way that Quality of Life (QoL) is perceived has crucially changed over the last few decades. As a consequence of demographic change and ongoing technical progress, QoL gained in importance and became established as a major outcome parameter in clinical trials. Scientists in the field of QoL differentiate between three categories: health-related, global and individual QoL. For the assessment of individual QoL, Becker et al. (2014) and Merk (2011) developed and validated an easily applicable and economical questionnaire; the SEIQoL-Q. The purpose of our study was to modify the SEIQoL-Q based on Merk's approach (2011) and apply the revised version in a longitudinal survey of different patient populations in the Clinic for Radiotherapy of the University Hospital of Freiburg. Apart from that, other crucial factors, which might affect the evaluation of one's QoL, were gathered by use of a newly established questionnaire. 132 patients undergoing radiotherapy and having been diagnosed with breast cancer (BC), prostate cancer (PC), bone metastasis (BM) or a benign disease (B) were included in our study. The participants were interviewed at four definitive times in their treatment (1. before the radiotherapy had started, 2. after 50 % of the total radiation dose had been given, 3. at the end of the therapy, 4. during the aftercare). A total of 419 interviews were carried out. While the highest possible score was 100, the average individual QoL was 60.48 (BC: 56.55; PC: 64.13; BM: 59.27; B: 58.85). Significant differences of the individual QoL were revealed between the diagnosis groups (BC vs. PC, PC vs. B, PC vs. BM), the age (< 66 years: 55.39; = 66 years: 62.27) and the gender (women: 57.11; men: 62.88). Additionally, the expectations and the mood influenced the assessment of the individual QoL. Furthermore, it could be shown that there were correlations between the individual QoL and personality, depressive tendencies, ego strength, optimism, self-concept, faith and

  8. Professional Problems Experienced by Information Technology Teachers and Suggested Solutions: Longitudinal Survey

    Directory of Open Access Journals (Sweden)

    Hafize Keser

    2013-02-01

    Full Text Available The study aimed to determine the opinions of teacher candidates in the fourth year of Computer Education & Instructional Technologies department (CEIT on the Problems Experienced by Information Technology (IT Teachers and Suggested Solutions and it has been designed in case study routine taking place within qualitative research tradition and in a longitudinal survey model. The final year IT teacher candidates receiving education in Ankara University Educational Sciences Faculty CEIT department in academic years 2011-2012 and 2012-2013 have formed the study group of the research (N=123. The data obtained in the research by open-end questionnaire have been analysed and interpreted by inductive encoding technique, freuency analysis and descriptive content analysis. At the end of the study carried out, it has been determined that the IT teacher candidates have handled in two sub-dimensions the problems experienced by the IT teachers, these being, problems towards the courses the IT teachers attend and problems regarding the professional lives of IT teachers and suggested solutions in line with these. The leading problems towards the courses the IT teachers attend are that the courses are optional, the courses are grade-free, the course hours are few, the significance of IT not being comprehended very well by the executives, teachers, parents and students, inadequacy of physical means of IT classes and references of the course. And, the main problems regarding professional lives of IT course teachers are the duty, power and responsibility of IT teachers not made clear enough, difficulties in formative teacher practice, course hours which have to be completed by IT teachers not being able to be completed and problem of permanent staff, the courses that must be attended by IT teachers being taugth by teachers from other branches, lack of executives and experts trained from a field to supervise IT and formative teachers. And, the suggested leading

  9. Trends in advance care planning in cancer patients: Results from a national, longitudinal survey

    Science.gov (United States)

    Narang, Amol K.; Wright, Alexi A.; Nicholas, Lauren H.

    2015-01-01

    Importance Advance care planning (ACP) may prevent end-of-life (EOL) care that is non-beneficial and discordant with patient wishes. Despite long-standing recognition of the merits of ACP in oncology, it is unclear whether cancer patients’ participation in ACP has increased over time. Objective To characterize trends in durable power of attorney (DPOA) assignment, living will creation, and participation in discussions of EOL care preferences, and to explore associations between ACP subtypes and EOL treatment intensity, as reflected in EOL care decisions and terminal hospitalizations. Design Prospectively collected survey data from the Health and Retirement Study (HRS), including data from in-depth “exit” interviews conducted with next-of-kin surrogates following the death of an HRS participant. Trends in ACP subtypes were tested, and multivariable logistic regression models examined associations between ACP subtypes and measures of treatment intensity. Setting HRS, a nationally representative, biennial, longitudinal panel study of U.S. residents over age 50. Participants 1,985 next-of-kin surrogates of HRS participants with cancer who died between 2000 and 2012. Main Outcome and Measures Trends in the surrogate-reported frequency of DPOA assignment, living will creation, and participation in discussions of EOL care preferences, as well as associations between ACP subtypes and surrogate-reported EOL care decisions/terminal hospitalizations. Results From 2000-2012, there was an increase in DPOA assignment (52% to 74%, p=0.03), without change in use of living wills (49% to 40%, p=0.63) or EOL discussions (68% to 60%, p=0.62). Surrogates increasingly reported that patients received “all care possible” at EOL (7% to 58%, p=0.004), and rates of terminal hospitalizations were unchanged (29% to 27%, p=0.70). Both living wills and EOL discussions were associated with limiting/withholding treatment [living will: adjusted odds ratio (AOR)=2.51, 95% confidence

  10. Trends in Advance Care Planning in Patients With Cancer: Results From a National Longitudinal Survey.

    Science.gov (United States)

    Narang, Amol K; Wright, Alexi A; Nicholas, Lauren H

    2015-08-01

    Advance care planning (ACP) may prevent end-of-life (EOL) care that is nonbeneficial and discordant with patient wishes. Despite long-standing recognition of the merits of ACP in oncology, it is unclear whether participation in ACP by patients with cancer has increased over time. To characterize trends in durable power of attorney (DPOA) assignment, living will creation, and participation in discussions of EOL care preferences and to explore associations between ACP subtypes and EOL treatment intensity as reflected in EOL care decisions and terminal hospitalizations. We analyzed prospectively collected survey data from 1985 next-of-kin surrogates of Health and Retirement Study (HRS) participants with cancer who died between 2000 and 2012, including data from in-depth "exit" interviews conducted with the surrogates after the participant's death. The HRS is a nationally representative, biennial, longitudinal panel study of US residents older than 50 years. Trends in ACP subtypes were tested, and multivariable logistic regression models examined for associations between ACP subtypes and measures of treatment intensity. Trends in the surrogate-reported frequency of DPOA assignment, living will creation, and participation in discussions of EOL care preferences; associations between ACP subtypes and both surrogate-reported EOL care decisions and terminal hospitalizations. From 2000 to 2012, there was an increase in DPOA assignment (52% to 74%, P = .03), without significant change in use of living wills (49% to 40%, P = .63) or EOL discussions (68% to 60%, P = .62). Surrogate reports that patients received "all care possible" at EOL increased during the period (7% to 58%, P = .004), and rates of terminal hospitalizations were unchanged (29% to 27%, P = .70). Limiting or withholding treatment was associated with living wills (adjusted odds ratio [AOR], 2.51; 95% CI, 1.53-4.11; P EOL discussions (AOR, 1.93; 95% CI, 1.53-3.14; P = .002) but not with

  11. Finnish physicians' stress related to information systems keeps increasing: a longitudinal three-wave survey study.

    Science.gov (United States)

    Heponiemi, Tarja; Hyppönen, Hannele; Vehko, Tuulikki; Kujala, Sari; Aalto, Anna-Mari; Vänskä, Jukka; Elovainio, Marko

    2017-10-17

    Poorly functioning, time-consuming, and inadequate information systems are among the most important work-related psychosocial factors causing stress in physicians. The present study examined the trend in the perceived stress that was related to information systems (SRIS) among Finnish physicians during a nine-year follow-up. In addition, we examined the associations of gender, age, employment sector, specialization status, leadership position, on-call burden, and time pressure with SRIS change and levels. A longitudinal design with three survey data collection waves (2006, 2010 and 2015) based on a random sample of Finnish physicians in 2006 was used. The study sample included 1095 physicians (62.3% women, mean age 54.4 years) who provided data on SRIS in every wave. GLM repeated measures analyses were used to examine the associations between independent variables and the SRIS trend during the years 2006, 2010, and 2015. SRIS increased during the study period. The estimated marginal mean of SRIS in 2006 was 2.80 (95% CI = 2.68-2.92) and the mean increase was 0.46 (95% CI = 0.30-0.61) points from 2006 to 2010 and 0.25 (95% CI = 0.11-0.39) points from 2010 to 2015. Moreover, our results show that the increase was most pronounced in primary care, whereas in hospitals SRIS did not increase between 2010 and 2015. SRIS increased more among those in a leadership position. On-call duties and high time-pressures were associated with higher SRIS levels during all waves. Changing, difficult, and poorly functioning information systems (IS) are a prominent source of stress among Finnish physicians and this perceived stress continues to increase. Organizations should implement arrangements to ease stress stemming from IS especially for those with a high workload and on-call or leadership duties. To decrease IS-related stress, it would be important to study in more detail the main IS factors that contribute to SRIS. Earlier studies indicate that the usability and stability

  12. Wellbeing at work among kitchen workers during organic food conversion in Danish public kitchens: a longitudinal survey

    DEFF Research Database (Denmark)

    Sørensen, Nina Nørgaard; Løje, Hanne; Tetens, Inge

    2016-01-01

    among kitchen workers before and after participating in educational training programmes in organic food conversion. Method: This longitudinal study applied an online self-administered questionnaire among kitchen workers before and after the implementation of an organic food conversion programme with 1......-up (63% of those surveyed at baseline). No substantive differences between baseline and follow-up measurements of organic food conversion were detected on physical or psychological wellbeing at work. Kitchen workers reported a significant improvement in the perceived food quality, motivation to work...

  13. Longitudinal Weight Calibration with Estimated Control Totals for Cross Sectional Survey Data: Theory and Application

    Science.gov (United States)

    Qing, Siyu

    2014-01-01

    The National Science Foundation (NSF) Survey of Doctorate Recipients (SDR) collects information on a sample of individuals in the United States with PhD degrees. A significant portion of the sampled individuals appear in multiple survey years and can be linked across time. Survey weights in each year are created and adjusted for oversampling and…

  14. Longitudinal control behaviour: Analysis and modelling based on experimental surveys in Italy and the UK.

    Science.gov (United States)

    Pariota, Luigi; Bifulco, Gennaro Nicola; Galante, Francesco; Montella, Alfonso; Brackstone, Mark

    2016-04-01

    This paper analyses driving behaviour in car-following conditions, based on extensive individual vehicle data collected during experimental field surveys carried out in Italy and the UK. The aim is to contribute to identify simple evidence to be exploited in the ongoing process of driving assistance and automation which, in turn, would reduce rear-end crashes. In particular, identification of differences and similarities in observed car-following behaviours for different samples of drivers could justify common tuning, at a European or worldwide level, of a technological solution aimed at active safety, or, in the event of differences, could suggest the most critical aspects to be taken into account for localisation or customisation of driving assistance solutions. Without intending to be exhaustive, this paper moves one step in this direction. Indeed, driving behaviour and human errors are considered to be among the main crash contributory factors, and a promising approach for safety improvement is the progressive introduction of increasing levels of driving automation in next-generation vehicles, according to the active/preventive safety approach. However, the more advanced the system, the more complex will be the integration in the vehicle, and the interaction with the driver may sometimes become unproductive, or risky, should the driver be removed from the driving control loop. Thus, implementation of these systems will require the interaction of human driving logics with automation logics and then an enhanced ability in modelling drivers' behaviour. This will allow both higher active-safety levels and higher user acceptance to be achieved, thus ensuring that the driver is always in the control loop, even if his/her role is limited to supervising the automatic logic. Currently, the driving mode most targeted by driving assistance systems is longitudinal driving. This is required in various driving conditions, among which car-following assumes key importance

  15. Does Seeking e-Cigarette Information Lead to Vaping? Evidence from a National Longitudinal Survey of Youth and Young Adults.

    Science.gov (United States)

    Yang, Qinghua; Liu, Jiaying; Lochbuehler, Kirsten; Hornik, Robert

    2017-12-13

    Youth and young adults (YYAs) are vulnerable populations for e-cigarette use or vaping. This study examined the effect of YYAs' health information seeking behavior (HISB) around e-cigarette use and vaping on their subsequent vaping behavior. We conducted a nationally representative longitudinal phone survey of 13-25 year olds from June 2014 to September 2016, with 2,413 respondents who completed a baseline and follow-up survey six months later. The results from lagged logistic regressions and mediation analyses showed a) that information seeking predicted higher likelihood of vaping six months later even after controlling for baseline smoking and vaping status, intention to vape, and demographics, and b) that information seeking partially mediated the relationship between intention to vape and subsequent vaping behavior. Theoretical and regulatory implications are discussed.

  16. Digital Divide and Health Disparities in China: Data from a National Longitudinal Survey of CHARLS.

    Science.gov (United States)

    Hong, Y Alicia; Zhou, Zi; Fang, Ya

    2017-01-01

    The China Health and Retirement Longitudinal Study (CHARLS, 2013) data was used to investigate internet use and mobile phone ownership in older Chinese adults and examine digital divide and social economic status and mobile technology adoption and health outcomes associations. Results suggest a significant digital divide associated with not only individual characteristics, but also neighborhood resources. Future eHealth programs should consider the accessibility of mobile tools and develop culturally appropriate programs for different social groups.

  17. Choir of believers? Longitudinal evidence on public service motivation and survey participation

    DEFF Research Database (Denmark)

    Jacobsen, Christian Bøtcher; De Lorent Gad, Mette; Kjeldsen, Anne Mette

    The most widely used method to study individuals’ public service motivation is surveys. The validity and inferential power of such studies may, however, be harmed by survey participation bias, if highly public service motivated individuals are overrepresented among respondents. This paper examines...... the methodological critique of survey participation bias raised against the public service motivation literature and examines whether public service motivation increases the propensity to respond to surveys. By tracking more than 3,000 public service providers’ participation in a three-wave panel survey, our...... analysis shows that public service motivation does have a positive effect on survey participation. This suggests that future studies should pay attention to the characteristics of respondents/non-respondents and consider weighting the sample....

  18. Perioperative management of diabetes in elective patients: a region-wide audit.

    Science.gov (United States)

    Jackson, M J; Patvardhan, C; Wallace, F; Martin, A; Yusuff, H; Briggs, G; Malik, R A

    2016-04-01

    Ten percent of elective surgical patients have diabetes. These patients demonstrate excess perioperative morbidity and mortality. National guidance on the management of adults with diabetes undergoing surgery was published in 2011. We present a region-wide audit of adherence to this guidance across the North Western Deanery. Local teams prospectively collected data according to a locally approved protocol. Pregnant, paediatric and non-elective patients were excluded from this audit. Patient characteristics, type of surgery and aspects of perioperative management were collated and centrally analysed against audit criteria based upon national recommendations. 247 patients with diabetes were identified. HbA1c was recorded in 71% of patients preoperatively; 9% of patients with an abnormal HbA1c were not known by, or referred to, the diabetes team. 17% of patients were admitted the evening preceding surgery. The mean fasting time was 12:20(4) h. Variable rate i.v. insulin infusions (VRIII) were not used when indicated in 11%. Only 8% of patients received the recommended substrate fluid, along with the VRIII (5% glucose in 0.45% saline). Intra-operative capillary blood glucose (CBG) was measured hourly in 56% of patients. Intra-operative CBG was within the acceptable range (4-12 mmol.L(-1)) in 85% of patients. 73% of patients had a CBG measurement performed in recovery. The WHO checklist was used in 95% of patients. National perioperative guidelines were not adhered to in a substantial proportion of patients with diabetes undergoing elective surgery. This study represents a template for future trainee networks. © The Author 2016. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. Adult parenteral nutrition in the North of England: a region-wide audit.

    Science.gov (United States)

    Dyson, Jessica K; Thompson, Nick

    2017-01-10

    Parenteral nutrition (PN) is widely used to provide nutritional support to patients with inaccessible or inadequate length of gut or non-functioning gut. The objective was to compare practice in PN administration to results of the National Confidential Enquiry into Patient Outcome and Death (NCEPOD) report, 'A Mixed Bag', and to establish whether good practice was being followed within this part of the UK. Using the Northern Nutrition Network (NNN), we examined the care of adult patients receiving PN in all 10 secondary care hospitals in our region. All patients receiving PN were included with no exclusions. Data were collected on 192 patients (51% females, median age 65 years (range 18-96)). A data collection tool was designed based on the recommendations of the NCEPOD report. PN was used for a median of 7 days with a 30-day mortality rate of 8%. Metabolic complications occurred in 34%, of which only 13% were avoidable. The catheter sepsis rate was 1.5 per 1000 PN days. The audit suggests that nutrition team input improves patient assessment prior to starting PN and review once PN is established. Risk of refeeding syndrome was identified in 75%. Areas for improvement are documentation of treatment goal (39%), review of PN constitution (38%), ensuring patients are weighed regularly (56%) and documentation of line-tip position (52%). This region-wide prospective audit suggests improved practice within the UK compared to the NCEPOD audit with lower mortality and line sepsis rates. However, documentation remains suboptimal. This work strengthens the case for introducing nutrition teams in hospitals without this service. These findings are likely to be reproduced across the UK and in other healthcare settings. We provide a template for similar audits of clinical practice. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  20. Malaria prevalence pattern observed in the highland fringe of Butajira, Southern Ethiopia: a longitudinal study from parasitological and entomological survey.

    Science.gov (United States)

    Tesfaye, Solomon; Belyhun, Yeshambel; Teklu, Takele; Mengesha, Tesfaye; Petros, Beyene

    2011-06-07

    In Ethiopia, information regarding highland malaria transmission is scarce, and no report has been presented from Butajira highland so far whether the appearance of malaria in the area was due to endemicity or due to highland malaria transmission. Thus this study aimed to determine the presence and magnitude of malaria transmission in Butajira. For parasitological survey, longitudinal study was conducted from October to December 2006. The entomological surveys were done from October to December 2006 and continued from April to May 2007. Both parasitological and entomological surveys were done using standard procedures. The parasitological result in all the survey months (October-December) showed an overall detection rate of 4.4% (48/1082) (CI 95%; 3.2-5.7%) malaria parasite. Among infected individuals, 32 (3.0%) of the infection was due to Plasmodium vivax and the rest 16 (1.5%) were due to Plasmodium falciparum. The highest prevalence 39(3.6%) of the parasite was observed in age groups of above 15 years old. Among the total tested, 25(2.3%) of males and 23(2.1%) of females had malaria infection. Among tested individuals, 38(5.3%) and 10 (2.7%) of infection was occurred in Misrak-Meskan (2100 m a.s.l) and Mirab-Meskan (2280 m a.s.l), respectively which was statistically significant (X2=3.72, P0.05). The entomological survey showed a collection of 602 larvae and 80 adult Anopheles. Anopheles christyi was the dominant species both in the first (45.3%) and in the second (35.4%) surveys; where as, Anopheles gambiae sensu lato comprised 4.7% and 14.6%, in the first and second surveys, respectively. Anopheles gambiae s.l comprises 55% of the adult collection, and both species were collected more from outdoors (57.5%). The number of An. christyi was higher in Mirab-Meskan (58. 3%) than Misrak-Meskan (41.7%) (Prisk of malaria and its control programme in the area must be given adequate attention to minimize potential epidemics. In addition, the current study should be

  1. Children of Immigrants Longitudinal Survey in Four European Countries (CILS4EU) [Dataset

    NARCIS (Netherlands)

    Kalter, F.; Heath, A.F.; Hewstone, M.; Jonsson, J.; Kalmijn, M.; Kogan, I.; Van Tubergen, F.; Kroneberg, C.; Andersson Rydell, L.; Brolin Låftman, S.

    2013-01-01

    The study currently consists of two waves of a panel survey of adolescents designed to study the complex causal mechanism of structural, social, and cultural integration of populations with experience. The data include surveys of students, parents, and teachers. It enables studying processes of

  2. A crisis resolution and home treatment team in Norway: a longitudinal survey study Part 2. Provision of professional services

    Directory of Open Access Journals (Sweden)

    Karlsson Bengt

    2012-09-01

    Full Text Available Abstract Background Crisis resolution and home treatment (CRHT is an emerging mode of delivering acute mental health care in the community. There is a paucity of knowledge regarding the workings of CRHT in the literature. This is the second paper in a series of three from the longitudinal survey of patients of a CRHT team in Norway, which was aimed at describing the characteristics of patients served, professional services provided, and clinical outcomes. This report focuses on the provision of professional services by the team. Methods The project was a descriptive, quantitative study based on the patient data from a longitudinal survey of one CRHT team in Norway. The participants of the survey, a total of 363 patients, constituted the complete registration of patients of this team in the period from February 2008 to July 2009. Results The average length of service by the team was about 15 days, and those with depression as the major symptom had the longest mean length of stay on the team. The team was engaged in providing a variety of services including individual treatments involving multiple professionals, group treatment meetings, and coordination activities involving external service sectors. While the type of professionals providing individual treatment was not associated with the severity level of clinical problems, those receiving various group treatment meetings had more serious level of clinical symptoms than those not receiving group treatment meetings. In addition coordination activities involving healthcare professionals and social services in the community were in line with the patients' clinical and social needs. The results of the study show that the team functioned effectively in addressing the general guidelines for the functioning of CRHT teams.

  3. Longitudinal Cut Method Revisited: A Survey on the Main Error Sources

    OpenAIRE

    Moriconi, Alessandro; Lalli, Francesco; Di Felice, Fabio; Esposito, Pier Giorgio; Piscopia, Rodolfo

    2000-01-01

    Some of the main error sources in wave pattern resistance determination were investigated. The experimental data obtained at the Italian Ship Model Basin (longitudinal wave cuts concerned with the steady motion of the Series 60 model and a hard-chine catamaran) were analyzed. It was found that, within the range of Froude numbers tested (0.225 ≤ Fr ≤ 0.345 for the Series 60 and 0.5 ≤ Fr ≤ 1 for the catamaran) two sources of uncertainty play a significant role: (i) the p...

  4. Willingness to Participate in Longitudinal Research Among People with Chronic Pain Who Take Medical Cannabis: A Cross-Sectional Survey.

    Science.gov (United States)

    Bachhuber, Marcus A; Arnsten, Julia H; Starrels, Joanna L; Cunningham, Chinazo O

    2018-01-01

    Background: Regulatory barriers limit clinical trials of medical cannabis in the United States. Longitudinal cohort studies may be one feasible alternative that could yield clinically relevant information. Willingness to participate in such studies is not known. Materials and Methods: In October 2016, we surveyed a convenience sample of patients with chronic pain from two New York registered organizations (responsible for growing, processing, distributing, and retailing medical cannabis products). After a vignette describing a longitudinal cohort study involving weekly patient-reported outcomes and quarterly assessments of physical functioning and urine and blood tests, we asked about respondents' willingness to participate. We examined willingness to participate, duration of participation, and frequency of data collections overall and by subgroups, using multivariable logistic regression models. Results: Of 405 respondents (estimated response rate: 30%), 54% were women and 81% were white non-Hispanic. Neuropathy was the most common pain condition (67%) followed by inflammatory bowel disease (19%). Of respondents, 94% (95% CI 92-97%) thought that the study should be done, 85% (95% CI 81-88%) would definitely or probably enroll if asked, 76% (95% CI 72-81%) would participate for ≥1 year, and 59% (95% CI 54-64%) would respond to questions at least daily. Older age was the only factor associated with lower willingness to participate, lower willingness to participate for ≥1 year, and lower willingness to respond to questions at least daily. Conclusions: Nearly all respondents were supportive of the proposed study and most reported that they would enroll if asked. Enhanced engagement with older individuals may be needed to promote equal enrollment. Recruitment for longitudinal cohort studies with frequent data collection appears feasible in this patient population.

  5. Food Habits, Lifestyle Factors and Mortality among Oldest Old Chinese: The Chinese Longitudinal Healthy Longevity Survey (CLHLS).

    Science.gov (United States)

    Shi, Zumin; Zhang, Tuohong; Byles, Julie; Martin, Sean; Avery, Jodie C; Taylor, Anne W

    2015-09-09

    There are few studies reporting the association between lifestyle and mortality among the oldest old in developing countries. We examined the association between food habits, lifestyle factors and all-cause mortality in the oldest old (≥80 years) using data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS). In 1998/99, 8959 participants aged 80 years and older took part in the baseline survey. Follow-up surveys were conducted every two to three years until 2011. Food habits were assessed using an in-person interview. Deaths were ascertained from family members during follow-up. Cox and Laplace regression were used to assess the association between food habits, lifestyle factors and mortality risk. There were 6626 deaths during 31,926 person-years of follow-up. Type of staple food (rice or wheat) was not associated with mortality. Daily fruit and vegetable intake was inversely associated with a higher mortality risk (hazard ratios (HRs): 0.85 (95% CI (confidence interval) 0.77-0.92), and 0.74 (0.66-0.83) for daily intake of fruit and vegetables, respectively). There was a positive association between intake of salt-preserved vegetables and mortality risk (consumers had about 10% increase of HR for mortality). Fruit and vegetable consumption were inversely, while intake of salt-preserved vegetables positively, associated with mortality risk among the oldest old. Undertaking physical activity is beneficial for the prevention of premature death.

  6. Food Habits, Lifestyle Factors and Mortality among Oldest Old Chinese: The Chinese Longitudinal Healthy Longevity Survey (CLHLS

    Directory of Open Access Journals (Sweden)

    Zumin Shi

    2015-09-01

    Full Text Available There are few studies reporting the association between lifestyle and mortality among the oldest old in developing countries. We examined the association between food habits, lifestyle factors and all-cause mortality in the oldest old (≥80 years using data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS. In 1998/99, 8959 participants aged 80 years and older took part in the baseline survey. Follow-up surveys were conducted every two to three years until 2011. Food habits were assessed using an in-person interview. Deaths were ascertained from family members during follow-up. Cox and Laplace regression were used to assess the association between food habits, lifestyle factors and mortality risk. There were 6626 deaths during 31,926 person-years of follow-up. Type of staple food (rice or wheat was not associated with mortality. Daily fruit and vegetable intake was inversely associated with a higher mortality risk (hazard ratios (HRs: 0.85 (95% CI (confidence interval 0.77–0.92, and 0.74 (0.66–0.83 for daily intake of fruit and vegetables, respectively. There was a positive association between intake of salt-preserved vegetables and mortality risk (consumers had about 10% increase of HR for mortality. Fruit and vegetable consumption were inversely, while intake of salt-preserved vegetables positively, associated with mortality risk among the oldest old. Undertaking physical activity is beneficial for the prevention of premature death.

  7. Sickness absence and psychosocial job quality: an analysis from a longitudinal survey of working Australians, 2005-2012.

    Science.gov (United States)

    Milner, Allison; Butterworth, Peter; Bentley, Rebecca; Kavanagh, Anne M; LaMontagne, Anthony D

    2015-05-15

    Sickness absence is associated with adverse health, organizational, and societal outcomes. Using data from a longitudinal cohort study of working Australians (the Household, Income and Labour Dynamics in Australia (HILDA) Survey), we examined the relationship between changes in individuals' overall psychosocial job quality and variation in sickness absence. The outcome variables were paid sickness absence (yes/no) and number of days of paid sickness absence in the past year (2005-2012). The main exposure variable was psychosocial job quality, measured using a psychosocial job quality index (levels of job control, demands and complexity, insecurity, and perceptions of unfair pay). Analysis was conducted using longitudinal fixed-effects logistic regression models and negative binomial regression models. There was a dose-response relationship between the number of psychosocial job stressors reported by an individual and the odds of paid sickness absence (1 adversity: odds ratio (OR) = 1.26, 95% confidence interval (CI): 1.09, 1.45 (P = 0.002); 2 adversities: OR = 1.28, 95% CI: 1.09, 1.51 (P = 0.002); ≥3 adversities: OR = 1.58, 95% CI: 1.29, 1.94 (P job quality. These results suggest that workplace interventions aiming to improve the quality of work could help reduce sickness absence. © The Author 2015. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  8. A Longitudinal Analysis of the Criminal Careers of Intimate Partner Violence Offender Subtypes: Results From a Prospective Survey of Males.

    Science.gov (United States)

    Theobald, Delphine; Farrington, David P; Coid, Jeremy W; Piquero, Alex R

    2016-12-01

    Using data from the Cambridge Study in Delinquent Development, a prospective longitudinal survey of more than 400 males in the United Kingdom followed from age 8 years to age 48 years, we investigated the role of Cluster B personality traits and the association with violent offending groups based on a typology theory of male intimate partner violence (IPV) perpetrators: those who committed family-only violence and the generally violent offender. We also considered whether offending/violent groups could be predicted using risk factors measured in childhood, adolescence, and adulthood. Our findings suggest that those men who are violent both within and outside the home (the generally violent men) are distinguished from those who are involved in IPV within the home only. The differences appear to be more in degree than in kind. We discuss these findings in relation to the idea of specific interventions and policy.

  9. Relation between social network and psychological distress among middle-aged adults in Japan: Evidence from a national longitudinal survey.

    Science.gov (United States)

    Fu, Rong; Noguchi, Harkuo; Tachikawa, Hirokazu; Aiba, Miyuki; Nakamine, Shin; Kawamura, Akira; Takahashi, Hideto; Tamiya, Nanako

    2017-02-01

    It is widely documented that psychological distress is negatively associated with social networks involvement. However, despite the theoretical postulations that social networks are crucial for alleviating psychological distress, no study has yet empirically confirmed the causality of this relationship. Thus, we used the random-effects generalized least squares method to investigate the effect of one- and two-year lagged values for involvement in social networks on psychological distress. Nine years of longitudinal data were extracted from a nationally representative survey in Japan ("The Longitudinal Survey of Middle-aged and Older Persons"). We utilized the Kessler 6 (K6) score to measure psychological distress among 15,242 respondents aged 50-59 years in the baseline year (2005), and stratified participants into three layers of social networks: inner (well-established friendship ties and participating in hobby activates), intermediary (neighborly ties), and outer (involvement in community activities). We found highly significant and negative associations between all three layers and K6 scores, with the strongest association being for the inner layer. We further observed that one-year lagged involvement in the inner and intermediary layers led to significantly lower K6 scores. However, the protective influences of social networks generally diminished over time. In addition, the protective influences of social network involvement on psychological distress were stronger for women than for men. Furthermore, involvement in social networks was especially important for improving mental health among people with psychological distress. These findings would be important for policymaking to prevent mental health deterioration among middle-aged adults in Japan. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Longitudinal Survey of Carotenoids in Human Milk from Urban Cohorts in China, Mexico, and the USA.

    Directory of Open Access Journals (Sweden)

    Tristan E Lipkie

    Full Text Available Emerging evidence indicates that carotenoids may have particular roles in infant nutrition and development, yet data on the profile and bioavailability of carotenoids from human milk remain sparse. Milk was longitudinally collected at 2, 4, 13, and 26 weeks postpartum from twenty mothers each in China, Mexico, and the USA in the Global Exploration of Human Milk Study (n = 60 donors, n = 240 samples. Maternal and neonatal plasma was analyzed for carotenoids from the USA cohort at 4 weeks postpartum. Carotenoids were analyzed by HPLC and total lipids by Creamatocrit. Across all countries and lactation stages, the top four carotenoids were lutein (median 114.4 nmol/L, β-carotene (49.4 nmol/L, β-cryptoxanthin (33.8 nmol/L, and lycopene (33.7 nmol/L. Non-provitamin A carotenoids (nmol/L and total lipids (g/L decreased (p0.05 with lactation stage. Total carotenoid content and lutein content were greatest from China, yet lycopene was lowest from China (p0.3. This enhanced understanding of neonatal exposure to carotenoids during development may help guide dietary recommendations and design of human milk mimetics.

  11. Longitudinal Survey of Carotenoids in Human Milk from Urban Cohorts in China, Mexico, and the USA.

    Science.gov (United States)

    Lipkie, Tristan E; Morrow, Ardythe L; Jouni, Zeina E; McMahon, Robert J; Ferruzzi, Mario G

    2015-01-01

    Emerging evidence indicates that carotenoids may have particular roles in infant nutrition and development, yet data on the profile and bioavailability of carotenoids from human milk remain sparse. Milk was longitudinally collected at 2, 4, 13, and 26 weeks postpartum from twenty mothers each in China, Mexico, and the USA in the Global Exploration of Human Milk Study (n = 60 donors, n = 240 samples). Maternal and neonatal plasma was analyzed for carotenoids from the USA cohort at 4 weeks postpartum. Carotenoids were analyzed by HPLC and total lipids by Creamatocrit. Across all countries and lactation stages, the top four carotenoids were lutein (median 114.4 nmol/L), β-carotene (49.4 nmol/L), β-cryptoxanthin (33.8 nmol/L), and lycopene (33.7 nmol/L). Non-provitamin A carotenoids (nmol/L) and total lipids (g/L) decreased (p0.05) with lactation stage. Total carotenoid content and lutein content were greatest from China, yet lycopene was lowest from China (pLutein, β-cryptoxanthin, and β-carotene, and lycopene concentrations in milk were significantly correlated to maternal plasma and neonatal plasma concentrations (pmilk and neonatal plasma (p>0.3). This enhanced understanding of neonatal exposure to carotenoids during development may help guide dietary recommendations and design of human milk mimetics.

  12. A National Longitudinal Survey of Medical Students' Intentions to Practice Among the Underserved.

    Science.gov (United States)

    O'Connell, Thomas F; Ham, Sandra A; Hart, Theodore G; Curlin, Farr A; Yoon, John D

    2018-01-01

    To explore students' intentions to practice in medically underserved areas. In January 2011, 960 third-year medical students from 24 MD-granting U.S. medical schools were invited to participate in a survey on their intention to practice in a medically underserved area. A follow-up survey was sent to participants in September 2011. Covariates included student demographics, medical school characteristics, environmental exposures, work experiences, sense of calling, and religious characteristics. Adjusted response rates were 564/919 (61.4%, first survey) and 474/564 (84.0%, follow-up survey). Among fourth-year medical students, an estimated 34.3% had an intention to practice among the underserved. In multivariate logistic regression modeling, predictors for intentions to practice among the underserved included growing up in an underserved setting (odds ratio [OR] range: 2.96-4.81), very strong sense of calling (OR range: 1.86-3.89), and high medical school social mission score (in fourth year: OR = 2.34 [95% confidence interval (CI), 1.31-4.21]). International experience was associated with favorable change of mind in the fourth year (OR = 2.86 [95% CI, 1.13-7.24]). High intrinsic religiosity was associated with intentions to practice primary care in underserved settings (in fourth year: OR = 2.29 [95% CI = 1.13-4.64]). Growing up in medically underserved settings, work experience in religiously affiliated organizations, very strong sense of calling, and high medical school social mission score were associated with intentions to practice in underserved areas. Lack of formative educational experiences may dissuade students from considering underserved practice.

  13. Malaria prevalence pattern observed in the highland fringe of Butajira, Southern Ethiopia: A longitudinal study from parasitological and entomological survey

    Directory of Open Access Journals (Sweden)

    Mengesha Tesfaye

    2011-06-01

    Full Text Available Abstract Background In Ethiopia, information regarding highland malaria transmission is scarce, and no report has been presented from Butajira highland so far whether the appearance of malaria in the area was due to endemicity or due to highland malaria transmission. Thus this study aimed to determine the presence and magnitude of malaria transmission in Butajira. Methods For parasitological survey, longitudinal study was conducted from October to December 2006. The entomological surveys were done from October to December 2006 and continued from April to May 2007. Both parasitological and entomological surveys were done using standard procedures. Results The parasitological result in all the survey months (October-December showed an overall detection rate of 4.4% (48/1082 (CI 95%; 3.2-5.7% malaria parasite. Among infected individuals, 32 (3.0% of the infection was due to Plasmodium vivax and the rest 16 (1.5% were due to Plasmodium falciparum. The highest prevalence 39(3.6% of the parasite was observed in age groups of above 15 years old. Among the total tested, 25(2.3% of males and 23(2.1% of females had malaria infection. Among tested individuals, 38(5.3% and 10 (2.7% of infection was occurred in Misrak-Meskan (2100 m a.s.l and Mirab-Meskan (2280 m a.s.l, respectively which was statistically significant (X2 = 3.72, P Plasmodium species declined from October to December, the trend was non-significant (X2 for trend = 0.49, P > 0.05. The entomological survey showed a collection of 602 larvae and 80 adult Anopheles. Anopheles christyi was the dominant species both in the first (45.3% and in the second (35.4% surveys; where as, Anopheles gambiae sensu lato comprised 4.7% and 14.6%, in the first and second surveys, respectively. Anopheles gambiae s.l comprises 55% of the adult collection, and both species were collected more from outdoors (57.5%. The number of An. christyi was higher in Mirab-Meskan (58. 3% than Misrak-Meskan (41.7% (P Conclusion

  14. Assessing the Impact of Research: A Case Study of the LSAY Research Innovation and Expansion Fund. Longitudinal Surveys of Australian Youth. Occasional Paper

    Science.gov (United States)

    Hargreaves, Jo

    2012-01-01

    The purpose of this project is to apply the framework developed by the National Centre for Vocational Education Research (NCVER) for measuring research impact to assess the outcomes of the research and activities funded under the Longitudinal Surveys of Australian Youth (LSAY) Research Innovation and Expansion Fund (RIEF). LSAY provides a rich…

  15. Short-Term and Long-Term Effects of Early Parental Employment on Children of the National Longitudinal Survey of Youth.

    Science.gov (United States)

    Harvey, Elizabeth

    1999-01-01

    Examined effects of early parental employment on children, using data from National Longitudinal Survey of Youth. Found that more work hours were associated with slightly lower cognitive development through age 9 and lower academic achievement before age 7, but not with behavior problems, compliance, or self-esteem. Early parental employment was…

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

    Science.gov (United States)

    National Centre for Vocational Education Research (NCVER), 2009

    2009-01-01

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

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

    Science.gov (United States)

    National Centre for Vocational Education Research (NCVER), 2009

    2009-01-01

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

  18. [Longitudinal survey and analysis among Chengdu residents on cognition and acceptance of implant dentures].

    Science.gov (United States)

    Zuo, Yanping; Wang, Yongyue; Wang, Luming; Du, Bing

    2014-08-01

    This study aims to survey the cognition and acceptance of implant dentures among Chengdu residents in 2005 and 2013 and to comparatively analyze the differences and influencing factors. A questionnaire was designed for this study. Its main content included basic demographics of respondents (gender, age, cultural level, and income level), cognition level of implant dentures (concept and main characteristics of implant dentures), main concern of respondents regarding implant dentures and medical institutions, and acceptance level of the price of implant dentures, among others. The sampling survey was carried out among Chengdu residents in 2005 and 2013 using the designed questionnaire. The results were then statistically analyzed. Up to 908 valid questionnaires in 2005 and 905 valid questionnaires in 2013 were obtained. The level of cognition of implant dentures was higher in 2013 than in 2005, and the correlation between cognition and cultural level and that between cognition and income level were both positive. However, the correlation between cognition and age was negative. The success rate for implant dentures and medical treatment technology of medical institutions were the factors that the respondents were mainly concerned with. The main methods for disseminating information on implant dentures were the internet, television, newspapers, magazines, and introduction by friends. With the development of the society's economy and the improvement of culture and income level of Chengdu residents, the cognition and acceptance level of implant dentures have gradualy increased. Meanwhile, health education and medical technology still need to be strengthened.

  19. Adolescent Internet Use, Social Integration, and Depressive Symptoms: Analysis from a Longitudinal Cohort Survey.

    Science.gov (United States)

    Strong, Carol; Lee, Chih-Ting; Chao, Lo-Hsin; Lin, Chung-Ying; Tsai, Meng-Che

    2018-05-01

    To examine the association between adolescent leisure-time Internet use and social integration in the school context and how this association affects later depressive symptoms among adolescents in Taiwan, using a large nationwide cohort study and the latent growth model (LGM) method. Data of 3795 students followed from the year 2001 to 2006 in the Taiwan Education Panel Survey were analyzed. Leisure-time Internet use was defined by the hours per week spent on (1) online chatting and (2) online games. School social integration and depressive symptoms were self-reported. We first used an unconditional LGM to estimate the baseline (intercept) and growth (slope) of Internet use. Next, another LGM conditioned with school social integration and depression was conducted. Approximately 10% of the participants reported engaging in online chatting and/or gaming for more than 20 hours per week. Internet use for online chatting showed an increase over time. School social integration was associated with the baseline amount (coefficient = -0.62, p < 0.001) but not the growth of leisure-time Internet use. The trend of Internet use was positively related to depressive symptoms (coefficient = 0.31, p < 0.05) at Wave 4. School social integration was initially associated with decreased leisure-time Internet use among adolescents. The growth of Internet use with time was not explainable by school social integration but had adverse impacts on depression. Reinforcing adolescents' bonding to school may prevent initial leisure-time Internet use. When advising on adolescent Internet use, health care providers should consider their patients' social networks and mental well-being.

  20. Longitudinal Trends in Fall Accidents in Community Dwelling Korean Adults: The 2008-2013 Korean Community Health Survey.

    Science.gov (United States)

    Hong, Ickpyo; Simpson, Annie N; Logan, Sarah; Woo, Hee-Soon

    2016-08-01

    To describe the longitudinal characteristics of unintentional fall accidents using a representative population-based sample of Korean adults. We examined data from the Korean Community Health Survey from 2008 to 2013. Univariate analysis and multivariable logistic regression were used to identify the characteristics of fall accidents in adults. Between 2008 and 2013, the incidence rate of fall accidents requiring medical treatment increased from 1,248 to 3,423 per 100,000 people (pfall accidents decreased from 38.12% to 23.16% (pfall accidents than males (pfall accidents was slippery floors (33.7% in 2011 and 36.3% in 2013). Between 2008 and 2010, variables associated with higher fall accident risk included specific months (August and September), old age, female gender, current drinker, current smoker, diabetes, osteoarthritis, osteoporosis, and depression. A high level of education and living with a partner were negatively associated with fall accident risk. In 2013, people experiencing more than 1 fall accident felt more fear of falling than those having no fall accidents (odds ratio [OR] for 1 fall, 2.12; 95% confidence interval [CI], 2.04-2.12; OR for more than 2 falls, 2.97; 95% CI, 2.83-3.10). The occurrence of fall accidents has consistently increased in Korea from 2008 to 2013. Future intervention studies are needed to reduce the increasing incidence rates of fall accidents in community dwelling adults.

  1. Longitudinal Trends in Fall Accidents in Community Dwelling Korean Adults: The 2008–2013 Korean Community Health Survey

    Science.gov (United States)

    Logan, Sarah

    2016-01-01

    Objective To describe the longitudinal characteristics of unintentional fall accidents using a representative population-based sample of Korean adults. Methods We examined data from the Korean Community Health Survey from 2008 to 2013. Univariate analysis and multivariable logistic regression were used to identify the characteristics of fall accidents in adults. Results Between 2008 and 2013, the incidence rate of fall accidents requiring medical treatment increased from 1,248 to 3,423 per 100,000 people (pfall accidents decreased from 38.12% to 23.16% (pfall accidents than males (pfall accidents was slippery floors (33.7% in 2011 and 36.3% in 2013). Between 2008 and 2010, variables associated with higher fall accident risk included specific months (August and September), old age, female gender, current drinker, current smoker, diabetes, osteoarthritis, osteoporosis, and depression. A high level of education and living with a partner were negatively associated with fall accident risk. In 2013, people experiencing more than 1 fall accident felt more fear of falling than those having no fall accidents (odds ratio [OR] for 1 fall, 2.12; 95% confidence interval [CI], 2.04–2.12; OR for more than 2 falls, 2.97; 95% CI, 2.83–3.10). Conclusion The occurrence of fall accidents has consistently increased in Korea from 2008 to 2013. Future intervention studies are needed to reduce the increasing incidence rates of fall accidents in community dwelling adults. PMID:27606272

  2. Association of childhood and teen school performance and obesity in young adulthood in the US National Longitudinal Survey of Youth.

    Science.gov (United States)

    Sobol-Goldberg, Shira; Rabinowitz, Jonathan

    2016-08-01

    The literature suggests an association between poor school performance and obesity. However, little is known about academic achievement and behavior as possible risk factors for future obesity. The analysis was based on data from 3172 participants aged 6 to 25years from the US National Longitudinal Survey conducted 1986 to 2010. Academic achievement, behavior problems and body mass index (BMI) were assessed at childhood (6-9) and teenhood (10-14). Height and weight were self-reported at pre-young adulthood (15-18) and young adulthood (19-25). Based on logistic regression stratified by sex and race/ethnicity, academic and behavioral deficiencies during childhood and teenhood were risk factors for young adult obesity with some sex and ethnic/racial differences. The highest prevalence rates of obesity by race/ethnicity and sex are as follows: black/Hispanic females, those in the lowest quartile of teen reading and math (32.8%); black/Hispanic males, those in lowest quartile of teen reading (26.1%); white males, those in the highest quartile of behavioral problems (21.9%); and white females, those in the lowest quartile teen math (23.2%). Poor school performance in childhood and teenhood is associated with an increased risk of adult obesity. Prospective studies should further examine the association of school performance and adult obesity and whether programs directed at improving school performance may have secondary gains in preventing obesity. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Does obesity contribute to non-fatal occupational injury? Evidence from the National Longitudinal Survey of Youth.

    Science.gov (United States)

    Lin, Tin-chi; Verma, Santosh K; Courtney, Theodore K

    2013-05-01

    The relationship between obesity and occupational injuries remains unclear in the literature due to limitations in study design and sample composition. To better assess the contribution of obesity to occupational injury, we used data from a nationally representative cohort, the National Longitudinal Survey of Youth 1979 (NLSY79) in 1988-2000. We hypothesized that obesity contributes to workplace injury and tested the hypothesis using logistic regression with generalized estimating equations (GEE) and random-effects logistic regression. To ensure temporal precedence of obesity, we used the obesity level in each previous wave and examined its association with injury outcome in each wave from 1988-2000. Obesity was measured as body mass index (BMI) based on self-reported height and weight. The GEE analysis showed that obesity was associated with 25% higher odds of workplace injury [odds ratio (OR) 1.25, 95% confidence interval (95% CI) 1.12-1.39; Pobese workers were associated with 29% higher odds of sustaining injuries than those of normal weight (OR 1.29, 95% CI 1.15-1.45; PObesity may predispose workers to work-related injury; further research is needed to elucidate the mechanisms.

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

    OpenAIRE

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

    2014-01-01

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

  5. The impact of smokefree legislation in Scotland: results from the Scottish ITC Scotland/UK longitudinal surveys

    Science.gov (United States)

    Hassan, Louise M.; Higbee, Cheryl; Boudreau, Christian; Fong, Geoffrey T.; Borland, Ron; Cummings, K. Michael; Yan, Mi; Thompson, Mary E.; Hastings, Gerard

    2009-01-01

    Background: To evaluate how Scotland's smokefree law impacted self-reported secondhand smoke (SHS) exposure in hospitality venues, workplaces and in people's homes. In addition, we examine changes in support for the law, pub and restaurant patronage, smoking cessation indicators and whether any observed changes varied by socioeconomic status. Methods: A quasi-experimental longitudinal telephone survey of nationally representative samples of smokers and non-smokers interviewed before the Scottish law (February to March 2006) and 1 year later after the law (March 2007) in Scotland (n = 705 smokers and n = 417 non-smokers) and the rest of the UK (n = 1027 smokers and n = 447 non-smokers) where smoking in public places was not regulated at the time. Results: Dramatic declines in the observance of smoking in pubs, restaurants and workplaces were found in Scotland relative to the rest of the UK. The change in the percent of smokers reporting a smokefree home and number of cigarettes smoked inside the home in the evening was comparable in Scotland and the rest of the UK. Support for smokefree policies increased to a greater extent in Scotland than in the rest of the UK. Self-reported frequency of going to pubs and restaurants was generally comparable between Scotland and the rest of the UK; however, non-smokers in Scotland were more likely to frequent pubs more often. No differences in smoking cessation indicators were observed between countries. Conclusion: The Scottish smokefree law has been successful in decreasing secondhand smoke exposure while causing none of the hypothesized negative outcomes. PMID:19151105

  6. Factors associated with unmet dental care needs in Canadian immigrants: an analysis of the longitudinal survey of immigrants to Canada.

    Science.gov (United States)

    Calvasina, Paola; Muntaner, Carles; Quiñonez, Carlos

    2014-12-03

    Immigrants are often considered to have poorer oral health than native born-populations. One possible explanation for immigrants' poor oral health is lack of access to dental care. There is very little information on Canadian immigrants' access to dental care, and unmet dental care needs. This study examines predictors of unmet dental care needs among a sample of adult immigrants to Canada over a three-point-five-year post-migration period. A secondary data analysis was conducted on the Longitudinal Survey of Immigrants to Canada (LSIC). Sampling and bootstrap weights were applied to make the data nationally representative. Simple descriptive analyses were conducted to describe the demographic characteristics of the sample. Bivariate and multiple logistic regression analyses were applied to identify factors associated with immigrants' unmet dental care needs over a three-point-five-year period. Approximately 32% of immigrants reported unmet dental care needs. Immigrants lacking dental insurance (OR = 2.63; 95% CI: 2.05-3.37), and those with an average household income of $20,000 to $40,000 per year (OR = 1.62; 95% CI: 1.01-2.61), and lower than $20,000 (OR = 2.25; 95% CI: 1.31-3.86), were more likely to report unmet dental care needs than those earning more than $60,000 per year. In addition, South Asian (OR = 1.85; CI: 1.25-2.73) and Chinese (OR = 2.17; CI: 1.47-3.21) immigrants had significantly higher odds of reporting unmet dental care needs than Europeans. Lack of dental insurance, low income and ethnicity predicted unmet dental care needs over a three-point-five-year period in a sample of immigrants to Canada.

  7. Wellbeing at work among kitchen workers during organic food conversion in Danish public kitchens: a longitudinal survey.

    Science.gov (United States)

    Sørensen, Nina N; Løje, Hanne; Tetens, Inge; Wu, Jason H Y; Neal, Bruce; Lassen, Anne D

    2016-04-01

    In 2011, the Danish Ministry of Food, Agriculture and Fisheries launched the Danish Organic Action Plan 2020 intending to double the organic agricultural area in Denmark. This study aims to measure experienced physical and psychological wellbeing at work along with beliefs and attitudes among kitchen workers before and after participating in educational training programmes in organic food conversion. This longitudinal study applied an online self-administered questionnaire among kitchen workers before and after the implementation of an organic food conversion programme with 1-year follow-up. The study targeted all staff members in the participating public kitchens taking part in the organic food conversion process funded by the Danish Organic Action Plan 2020. Of the 448 eligible kitchen workers, 235 completed the questionnaire at baseline (52%) and 149 at follow-up (63% of those surveyed at baseline). No substantive differences between baseline and follow-up measurements of organic food conversion were detected on physical or psychological wellbeing at work. Kitchen workers reported a significant improvement in the perceived food quality, motivation to work and application of nutritional guidelines. Reported organic food percentages for the kitchens also increased significantly (Pfood products to producing more food from base was indicated. Within 1 year, a significant increase in motivation to work among kitchen staff was observed with no substantive changes in physical or psychological wellbeing at work identified. The results support the Danish Organic Action Plan 2020 and initiatives of similar kind. © The Author 2015. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

  8. Socio-geographic mobility and health status: a longitudinal analysis using the National Population Health Survey of Canada.

    Science.gov (United States)

    Curtis, Sarah; Setia, Maninder S; Quesnel-Vallee, Amelie

    2009-12-01

    The paper reviews arguments that associations between small area socio-economic conditions and individual health are likely to vary according to the type of health condition considered. We comment on the importance of longitudinal research to examine how far area conditions predict later health outcomes, and also how far area variations in health may result from selective migration processes predicted by health status. Using data for 1996 and 2002, from the National Population Health Survey of Canada, linked to small area data on social and on material deprivation in the area of residence for 6950 survey respondents at the two time points, we report on analyses to address these questions. The area measures of material and social deprivation were previously developed by Pampalon and colleagues at the Institut National de Santé Publique de Québec and related to the dissemination area matching the informant's postal code. The health outcomes considered were restriction of activity due to chronic conditions and psychological distress. Our findings suggest that individuals living in materially deprived areas in 2002 were more likely to be affected by health conditions resulting in restriction of activity. Prevalence of psychological distress was higher in areas with greater social deprivation in 2002. Most of these area differences were attenuated when adjustment was made for individual socio-demographic characteristics. Measures recorded in 1996 of individual characteristics and measures of deprivation for area of residence were used to predict change in health outcomes by 2002. Several individual factors (sex, age group, income, household composition) in 1996 were predictive of later health outcomes. After controlling for these individual characteristics the only significant association between health change and area deprivation was with development of restricted activity, which was more common among people who, in 1996, had lived in areas that ranked moderately

  9. From community-based pilot testing to region-wide systems change: lessons from a local quality improvement collaborative.

    Science.gov (United States)

    Keyser, Donna J; Pincus, Harold Alan

    2010-01-01

    A community-based collaborative conducted a 2-year pilot study to inform efforts for improving maternal and child health care practice and policy in Allegheny County, Pennsylvania. (1) To test whether three small-scale versions of an evidence-based, systems improvement approach would be workable in local community settings and (2) to identify specific policy/infrastructure reforms for sustaining improvements. A mixed methods approach was used, including quantitative performance measurement supplemented with qualitative data about factors related to outcomes of interest, as well as key stakeholder interviews and a literature review/Internet search. Quantitative performance results varied; qualitative data revealed critical factors for the success and failure of the practices tested. Policy/infrastructure recommendations were developed to address specific practice barriers. This information was important for designing a region-wide quality improvement initiative focused on maternal depression. The processes and outcomes provide valuable insights for other communities interested in conducting similar quality improvement initiatives.

  10. Temporal variation of residential pesticide use and comparison of two survey platforms: a longitudinal study among households with young children in Northern California.

    Science.gov (United States)

    Wu, Xiangmei May; Bennett, Deborah H; Ritz, Beate; Tancredi, Daniel J; Hertz-Picciotto, Irva

    2013-08-20

    consistently applied in the bathroom and kitchen. Outdoor sprays were consistently more often applied by male household members, while indoor sprays were not. The two survey approaches obtained fairly similar results on the prevalence of using pesticides, but found discrepancies in use frequencies. In addition, the number of products purchased was positively correlated with application frequency for outdoor sprays (R = 0.51, p = 0.0005) but not for indoor sprays. In this population, repeated surveys are necessary either to obtain a reliable estimate of the average household use of pesticides or to project potential temporal changes of pesticide use. Web surveys could collect comparable data to traditional telephone surveys for some information. However, researchers need to consider the internet acceptability among the target population and balance lower participant burden against the need for sufficiently accurate time-varying measurement, to improve subject retention in longitudinal surveys.

  11. Individual quality of life in patients undergoing radiotherapy. A longitudinal survey; Individuelle Lebensqualitaet von Strahlentherapie-Patienten. Eine Laengsschnittuntersuchung

    Energy Technology Data Exchange (ETDEWEB)

    Wenskus, Julia Katharina

    2015-07-01

    The way that Quality of Life (QoL) is perceived has crucially changed over the last few decades. As a consequence of demographic change and ongoing technical progress, QoL gained in importance and became established as a major outcome parameter in clinical trials. Scientists in the field of QoL differentiate between three categories: health-related, global and individual QoL. For the assessment of individual QoL, Becker et al. (2014) and Merk (2011) developed and validated an easily applicable and economical questionnaire; the SEIQoL-Q. The purpose of our study was to modify the SEIQoL-Q based on Merk's approach (2011) and apply the revised version in a longitudinal survey of different patient populations in the Clinic for Radiotherapy of the University Hospital of Freiburg. Apart from that, other crucial factors, which might affect the evaluation of one's QoL, were gathered by use of a newly established questionnaire. 132 patients undergoing radiotherapy and having been diagnosed with breast cancer (BC), prostate cancer (PC), bone metastasis (BM) or a benign disease (B) were included in our study. The participants were interviewed at four definitive times in their treatment (1. before the radiotherapy had started, 2. after 50 % of the total radiation dose had been given, 3. at the end of the therapy, 4. during the aftercare). A total of 419 interviews were carried out. While the highest possible score was 100, the average individual QoL was 60.48 (BC: 56.55; PC: 64.13; BM: 59.27; B: 58.85). Significant differences of the individual QoL were revealed between the diagnosis groups (BC vs. PC, PC vs. B, PC vs. BM), the age (< 66 years: 55.39; = 66 years: 62.27) and the gender (women: 57.11; men: 62.88). Additionally, the expectations and the mood influenced the assessment of the individual QoL. Furthermore, it could be shown that there were correlations between the individual QoL and personality, depressive tendencies, ego strength, optimism, self

  12. Physical after-effects of colposcopy and related procedures, and their inter-relationship with psychological distress: a longitudinal survey.

    Science.gov (United States)

    O'Connor, M; O'Brien, K; Waller, J; Gallagher, P; D'Arcy, T; Flannelly, G; Martin, C M; McRae, J; Prendiville, W; Ruttle, C; White, C; Pilkington, L; O'Leary, J J; Sharp, L

    2017-08-01

    To estimate prevalence of post-colposcopy physical after-effects and investigate associations between these and subsequent psychological distress. Longitudinal survey. Two hospital-based colposcopy clinics. Women with abnormal cytology who underwent colposcopy (±related procedures). Questionnaires were mailed to women 4, 8 and 12 months post-colposcopy. Details of physical after-effects (pain, bleeding and discharge) experienced post-colposcopy were collected at 4 months. Colposcopy-specific distress was measured using the Process Outcome-Specific Measure at all time-points. Linear mixed-effects regression was used to identify associations between physical after-effects and distress over 12 months, adjusting for socio-demographic and clinical variables. Prevalence of post-colposcopy physical after-effects. Associations between the presence of any physical after-effects, awareness of after-effects, and number of after-effects and distress. Five-hundred and eighty-four women were recruited (response rate = 73, 59 and 52% at 4, 8 and 12 months, respectively). Eighty-two percent of women reported one or more physical after-effect(s). Multiple physical after-effects were common (two after-effects = 25%; three after-effects = 25%). Psychological distress scores declined significantly over time. In adjusted analyses, women who experienced all three physical after-effects had on average a 4.58 (95% CI: 1.10-8.05) higher distress scored than those who experienced no after-effects. Women who were unaware of the possibility of experiencing after-effects scored significantly higher for distress during follow-up. The prevalence of physical after-effects of colposcopy and related procedures is high. The novel findings of inter-relationships between awareness of the possibility of after-effects and experiencing multiple after-effects, and post-colposcopy distress may be relevant to the development of interventions to alleviate post-colposcopy distress. Experiencing multiple

  13. Web-Face-to-Face Mixed-Mode Design in a Longitudinal Survey: Effects on Participation Rates, Sample Composition, and Costs

    Directory of Open Access Journals (Sweden)

    Bianchi Annamaria

    2017-06-01

    Full Text Available Sequential mixed-mode designs are increasingly considered as an alternative to interviewer-administered data collection, allowing researchers to take advantage of the benefits of each mode. We assess the effects of the introduction of a sequential web-face-to-face mixed-mode design over three waves of a longitudinal survey in which members were previously interviewed face-to-face. Findings are reported from a large-scale randomised experiment carried out on the UK Household Longitudinal Study. No differences are found between the mixed-mode design and face-to-face design in terms of cumulative response rates and only minimal differences in terms of sample composition. On the other hand, potential cost savings are evident.

  14. Relationship between Mobile Phone Addiction and the Incidence of Poor and Short Sleep among Korean Adolescents: a Longitudinal Study of the Korean Children & Youth Panel Survey

    OpenAIRE

    Lee, Joo Eun; Jang, Sung-In; Ju, Yeong Jun; Kim, Woorim; Lee, Hyo Jung; Park, Eun-Cheol

    2017-01-01

    Three of ten teenagers in Korea are addicted to mobile phones. The aim of this study was to examine the relationship between mobile phone addiction and the incidence of poor sleep quality and short sleep duration in adolescents. We used longitudinal data from the Korean Children & Youth Panel Survey conducted by the National Youth Policy Institute in Korea (2011?2013). A total of 1,125 students at baseline were included in this study after excluding those who already had poor sleep quality or...

  15. Drug use among complete responders, partial responders and non-responders in a longitudinal survey of nonagenarians

    DEFF Research Database (Denmark)

    Wastesson, Jonas W; Rasmussen, Lotte; Oksuzyan, Anna

    2017-01-01

    PURPOSE: In observational studies, non-response can limit representativity and introduce bias. We aimed to investigate the longitudinal changes in the number of used drugs among complete responders, partial responders, and non-responders in a whole birth cohort of Danish nonagenarians participati...

  16. The Longitudinal Relation between Childhood Autistic Traits and Psychosexual Problems in Early Adolescence: The Tracking Adolescents' Individual Lives Survey Study

    Science.gov (United States)

    Dekker, Linda P.; Hartman, Catharina A.; van der Vegt, Esther J. M.; Verhulst, Frank C.; van Oort, Floor V. A.; Greaves-Lord, Kirstin

    2015-01-01

    Individuals with autistic traits are considered to be prone to develop psychosexual problems due to their limited social skills and insight. This study investigated the longitudinal relation between autistic traits in childhood (T1; age 10-12 years) and parent-reported psychosexual problems in early adolescence (T2; age 12-15 years). In a general…

  17. The longitudinal relation between childhood autistic traits and psychosexual problems in early adolescence : The Tracking Adolescents' Individual Lives Survey study

    NARCIS (Netherlands)

    Dekker, Linda P.; Hartman, Catharina A.; van der Vegt, Esther J. M.; Verhulst, Frank C.; van Oort, Floor V. A.; Greaves-Lord, Kirstin

    Individuals with autistic traits are considered to be prone to develop psychosexual problems due to their limited social skills and insight. This study investigated the longitudinal relation between autistic traits in childhood (T1; age 10-12 years) and parent-reported psychosexual problems in early

  18. Implications of Attrition in a Longitudinal Web-Based Survey: An Examination of College Students Participating in a Tobacco Use Study.

    Science.gov (United States)

    McDonald, Bennett; Haardoerfer, Regine; Windle, Michael; Goodman, Michael; Berg, Carla

    2017-10-16

    Web-based survey research has several benefits, including low cost and burden, as well as high use of the Internet, particularly among young adults. In the context of longitudinal studies, attrition raises concerns regarding the validity of data, given the potential associations with individual and institutional characteristics, or the focal area of study (eg, cigarette use). The objective of this study was to compare baseline characteristics of nonresponders versus responders in a sample of young adult college students in a Web-based longitudinal study regarding tobacco use. We conducted a secondary data analysis of 3189 college students from seven Georgia colleges and universities in a 2-year longitudinal study. We examined baseline tobacco use, as well as individual- and institutional-level factors, as predictors of attrition between wave 1 (October and November 2014) and wave 2 (February and March 2015) using multilevel modeling. Results: A total 13.14% (419/3189) participants were lost to follow-up at wave 2. Predictors of nonresponse were similar in the models examining individual-level factors and institutional-level factors only and included being black versus white (odds ratio [OR] 1.74, CI 1.23-2.46); being male versus female (OR 1.41, CI 1.10-1.79); seeking a bachelor's degree versus advanced degree (OR 1.41, CI 1.09-1.83); not residing on campus (OR 0.62, CI 0.46-0.84); past 30-day tobacco use (OR 1.41, CI 1.10-1.78); attending a nonprivate college (OR 0.48, CI 0.33-0.71); and attending a college with ≤10,000 students (OR 0.56, CI 0.43-0.73). Future longitudinal studies should assess predictors of attrition to examine how survey topic and other individual and institutional factors might influence the response to allow for correction of selection bias. ©Bennett McDonald, Regine Haardoerfer, Michael Windle, Michael Goodman, Carla Berg. Originally published in JMIR Public Health and Surveillance (http://publichealth.jmir.org), 16.10.2017.

  19. The Precision of Category Versus Continuous Economic Data: Evidence from the Longitudinal Research on Officer Careers Survey

    Science.gov (United States)

    1992-08-01

    Hill, D. H. (1985). An investigation of the extent and consequences of measurement error in labor-economic survey data. Journal of Labor Economics , 4...from the Seattle-Denver experiment. Journal of Labor Economics , 4, 380- 407. Griliches, G. & Intriligator, M. (Eds.). (1986). Handbook of econometrics...W., & Sider, H. (1983). Accuracy of response in labor market surveys: Evidence and implication. Journal of Labor Economics , A, 331-344. 13 APPENDIX A

  20. Relationship between Mobile Phone Addiction and the Incidence of Poor and Short Sleep among Korean Adolescents: a Longitudinal Study of the Korean Children & Youth Panel Survey.

    Science.gov (United States)

    Lee, Joo Eun; Jang, Sung In; Ju, Yeong Jun; Kim, Woorim; Lee, Hyo Jung; Park, Eun Cheol

    2017-07-01

    Three of ten teenagers in Korea are addicted to mobile phones. The aim of this study was to examine the relationship between mobile phone addiction and the incidence of poor sleep quality and short sleep duration in adolescents. We used longitudinal data from the Korean Children & Youth Panel Survey conducted by the National Youth Policy Institute in Korea (2011-2013). A total of 1,125 students at baseline were included in this study after excluding those who already had poor sleep quality or short sleep duration in the previous year. A generalized estimating equation was used to analyze the data. High mobile phone addiction (mobile phone addiction score > 20) increased the risk of poor sleep quality but not short sleep duration. We suggest that consistent monitoring and effective intervention programs are required to prevent mobile phone addiction and improve adolescents' sleep quality. © 2017 The Korean Academy of Medical Sciences.

  1. Contrasts Between Young Males Dying by Suicide, Those Dying From Other Causes and Those Still Living: Observations From the National Longitudinal Survey of Adolescent to Adult Health.

    Science.gov (United States)

    Feigelman, William; Joiner, Thomas; Rosen, Zohn; Silva, Caroline; Mueller, Anna S

    2016-07-02

    Utilizing Add Health longitudinal data, we compared 21 male suicide casualties to 10,101 living respondents identifying suicide correlates. 21 suicide decedents completed surveys in 1994/1995 (Wave 1) and 11 completed at Wave 3; responses were compared with Chi-square and oneway ANOVA tests. Suicide decedents were prone to higher delinquency and fighting at Wave 1, but not at Wave 3. At Wave 1 suicide decedents remained undistinguished from living respondents in depression, self-esteem, and drug uses. Yet, after Wave 3, the 11 respondents dying by suicide showed significantly higher depression, drug use and lower self-esteem. Delinquency trends can readily understood, but more complex causes are needed to account for unexpected changes in self-esteem, depression and drug uses.

  2. Relationship between Mobile Phone Addiction and the Incidence of Poor and Short Sleep among Korean Adolescents: a Longitudinal Study of the Korean Children & Youth Panel Survey

    Science.gov (United States)

    2017-01-01

    Three of ten teenagers in Korea are addicted to mobile phones. The aim of this study was to examine the relationship between mobile phone addiction and the incidence of poor sleep quality and short sleep duration in adolescents. We used longitudinal data from the Korean Children & Youth Panel Survey conducted by the National Youth Policy Institute in Korea (2011–2013). A total of 1,125 students at baseline were included in this study after excluding those who already had poor sleep quality or short sleep duration in the previous year. A generalized estimating equation was used to analyze the data. High mobile phone addiction (mobile phone addiction score > 20) increased the risk of poor sleep quality but not short sleep duration. We suggest that consistent monitoring and effective intervention programs are required to prevent mobile phone addiction and improve adolescents' sleep quality. PMID:28581275

  3. Trends and Correlates of Consenting to Provide Social Security Numbers: Longitudinal Findings from the General Social Survey (1993-2010)

    Science.gov (United States)

    Kim, Jibum; Shin, Hee-Choon; Rosen, Zohn; Kang, Jeong-han; Dykema, Jennifer; Muennig, Peter

    2015-01-01

    Privacy and confidentiality are often of great concern to respondents answering sensitive questions posed by interviewers. Using the 1993-2010 General Social Survey, we examined trends in the provision of social security numbers (SSNs) and correlates of those responses. Results indicate that the rate of SSN provision has declined over the past…

  4. Longitudinal survey of public opinion toward nuclear power generation. The result of a survey conducted one year after the Mihama Unit 3 accident

    International Nuclear Information System (INIS)

    Kitada, Atsuko

    2006-01-01

    As part of an ongoing public opinion survey, regarding nuclear power generation, which started in 1993, a survey was carried out in the Kansai area in 2005, one year and two months after the accident at Unit 3 of the Mihama Nuclear Power Plant. It was found that people's memory about the accident decreased drastically. All questionnaire items that indicated a negative change two months after the accident returned to pre-accident levels. It was confirmed that the accident had only a temporary influence on public opinions. Moreover, the study also revealed a decrease in the public distrust of unclear power. It seems that people's evaluation of and attitude toward nuclear power generation have become slightly more positive since 2002. (author)

  5. A survey of the administration of drugs to young infants. The Alspac Survey Team. Avon Longitudinal Study of Pregnancy and Childhood.

    Science.gov (United States)

    Hawkins, N; Golding, J

    1995-01-01

    Medication which is given to young infants during the first months of life, an important period of development, may have effects on development which would not be observed in adults receiving the same drugs. The aim of this study was to estimate the numbers of children receiving various types of medication, including both prescription and non-prescription drugs, during the first 6 months of life. Self-completion questionnaires were posted to mothers participating in the Avon Longitudinal Study of Pregnancy & Childhood (ALSPAC) when their children were 6 months of age. These questionnaires included enquiries about the administration of drugs to the study children. The study was based in the three Bristol-based health districts of Avon in the United Kingdom. The study population comprised of 6973 children born in the 12 month period between the 1st July 1991 and the 30th June 1992. The majority of mothers, 96%, reported that their children had received medication, excluding vaccines, during the first 6 months of life. 35% had been given drugs from four or more different classes. Paracetamol had been given to 84% of the children, antibiotics to 30%. In view of potential effects of drug exposure on long term development, it is important that drugs which are administered to children are carefully assessed to ensure that they are not harmful. PMID:8527273

  6. Longitudinal clinical and serological survey of abdominal angiostrongyliasis in Guaporé, southern Brazil, from 1995 to 1999

    Directory of Open Access Journals (Sweden)

    Graeff-Teixeira Carlos

    2005-01-01

    Full Text Available Abdominal angiostrongyliasis is a zoonotic infection caused by Angiostrongylus costaricensis, a nematode with an intra-vascular location in the mesentery. Our objective was to address several aspects of the natural history of this parasitosis, in a longitudinal clinical and seroepidemiological study. A total of 179 individuals living in a rural area with active transmission in southern Brazil were followed for five years (1995-1999 resulting in yearly prevalence of 28.2%, 4.2%, 10%, 20.2% and 2.8% and incidences of 0%, 5.9%, 8% and 1.5%, respectively. Both men and woman were affected with higher frequencies at age 30-49 years. In 32 individuals serum samples were collected at all time points and IgG antibody reactivity detected by ELISA was variable and usually persisting not longer than one year. Some individual antibody patterns were suggestive of re-infection. There was no association with occurrence of abdominal pain or of other enteroparasites and there was no individual with a confirmed (histopathologic diagnosis. Mollusks were found with infective third-stage larvae in some houses with an overall prevalence of 16% and a low parasitic burden. In conclusion, abdominal angiostrongyliasis in southern Brazil may be a frequent infection with low morbidity and a gradually decreasing serological reactivity.

  7. HIV Futures 8: Protocol for a Repeated Cross-sectional and Longitudinal Survey of People Living with HIV in Australia

    OpenAIRE

    Power, Jennifer; Brown, Graham; Lyons, Anthony; Thorpe, Rachel; Dowsett, Gary W.; Lucke, Jayne

    2017-01-01

    Introduction More than 27,000 Australians currently live with HIV. Most of these people have access to quality clinical care and antiretroviral treatment (ART) and can expect good general health. However, HIV-related stigma is a problem and many people living with HIV experience poorer than average mental health. Issues of aging are also of increasing concern. This paper describes the methods and sample for the HIV Futures 8 study, a national survey of people living with HIV in Australia that...

  8. Patterns of cognitive dissonance-reducing beliefs among smokers: a longitudinal analysis from the International Tobacco Control (ITC) Four Country Survey.

    Science.gov (United States)

    Fotuhi, Omid; Fong, Geoffrey T; Zanna, Mark P; Borland, Ron; Yong, Hua-Hie; Cummings, K Michael

    2013-01-01

    The purpose of this paper is to assess whether smokers adjust their beliefs in a pattern that is consistent with Cognitive Dissonance Theory. This is accomplished by examining the longitudinal pattern of belief change among smokers as their smoking behaviours change. A telephone survey was conducted of nationally representative samples of adult smokers from Canada, the USA, the UK and Australia from the International Tobacco Control Four Country Survey. Smokers were followed across three waves (October 2002 to December 2004), during which they were asked to report on their smoking-related beliefs and their quitting behaviour. Smokers with no history of quitting across the three waves exhibited the highest levels of rationalisations for smoking. When smokers quit smoking, they reported having fewer rationalisations for smoking compared with when they had previously been smoking. However, among those who attempted to quit but then relapsed, there was once again a renewed tendency to rationalise their smoking. This rebound in the use of rationalisations was higher for functional beliefs than for risk-minimising beliefs, as predicted by social psychological theory. Smokers are motivated to rationalise their behaviour through the endorsement of more positive beliefs about smoking, and these beliefs change systematically with changes in smoking status. More work is needed to determine if this cognitive dissonance-reducing function has an inhibiting effect on any subsequent intentions to quit.

  9. External Quality Control for Dried Blood Spot Based C-reactive Protein Assay: Experience from the Indonesia Family Life Survey and the Longitudinal Aging Study in India

    Science.gov (United States)

    Hu, Peifeng; Herningtyas, Elizabeth H.; Kale, Varsha; Crimmins, Eileen M.; Risbud, Arun R.; McCreath, Heather; Lee, Jinkook; Strauss, John; O’Brien, Jennifer C.; Bloom, David E.; Seeman, Teresa E.

    2015-01-01

    Measurement of C-reactive protein, a marker of inflammation, in dried blood spots has been increasingly incorporated in community-based social surveys internationally. Although the dried blood spot based CRP assay protocol has been validated in the United States, it remains unclear whether laboratories in other less developed countries can generate C-reactive protein results of similar quality. We therefore conducted external quality monitoring for dried blood spot based C-reactive protein measurement for the Indonesia Family Life Survey and the Longitudinal Aging Study in India. Our results show that dried blood spot based C-reactive protein results in these two countries have excellent and consistent correlations with serum-based values and dried blood spot based results from the reference laboratory in the United States. Even though the results from duplicate samples may have fluctuations in absolute values over time, the relative order of C-reactive protein levels remains similar and the estimates are reasonably precise for population-based studies that investigate the association between socioeconomic factors and health. PMID:25879265

  10. Patterns of cognitive dissonance-reducing beliefs among smokers: a longitudinal analysis from the International Tobacco Control (ITC) Four Country Survey

    Science.gov (United States)

    Fotuhi, Omid; Fong, Geoffrey T; Zanna, Mark P; Borland, Ron; Yong, Hua-Hie; Cummings, K Michael

    2013-01-01

    Objective The purpose of this paper is to assess whether smokers adjust their beliefs in a pattern that is consistent with Cognitive Dissonance Theory. This is accomplished by examining the longitudinal pattern of belief change among smokers as their smoking behaviours change. Methods A telephone survey was conducted of nationally representative samples of adult smokers from Canada, the USA, the UK and Australia from the International Tobacco Control Four Country Survey. Smokers were followed across three waves (October 2002 to December 2004), during which they were asked to report on their smoking-related beliefs and their quitting behaviour. Findings Smokers with no history of quitting across the three waves exhibited the highest levels of rationalisations for smoking. When smokers quit smoking, they reported having fewer rationalisations for smoking compared with when they had previously been smoking. However, among those who attempted to quit but then relapsed, there was once again a renewed tendency to rationalise their smoking. This rebound in the use of rationalisations was higher for functional beliefs than for risk-minimising beliefs, as predicted by social psychological theory. Conclusions Smokers are motivated to rationalise their behaviour through the endorsement of more positive beliefs about smoking, and these beliefs change systematically with changes in smoking status. More work is needed to determine if this cognitive dissonance-reducing function has an inhibiting effect on any subsequent intentions to quit. PMID:22218426

  11. Gender shift in realisation of preferred type of gp practice: longitudinal survey over the last 25 years

    Science.gov (United States)

    Maiorova, Tanja; Stevens, Fred; van der Velden, Lud; Scherpbier, Albert; van der Zee, Jouke

    2007-01-01

    Background An increasing number of newly trained Dutch GPs prefer to work in a group practice and as a non-principal rather than in a single-handed practice. In view of the greater number of female doctors, changing practice preferences, and discussions on future workforce problems, the question is whether male and female GPs were able to realise their initial preferences in the past and will be able to do so in the future. Methods We have conducted longitudinal cohort study of all GPs in the Netherlands seeking a practice between 1980 and 2004. The Netherlands Institute of Health Services Research (NIVEL) in Utrecht collected the data used in this study by means of a postal questionnaire. The overall mean response rate was 94%. Results Over the past 20 years, an increasing proportion of GPs, both male and female, were able to achieve their preference for working in a group practice and/or in a non-principal position. Relatively more women than men have settled in group practices, and more men than women in single-handed practices; however, the practice preference of men and women is beginning to converge. Dropout was highest among the GPs without any specific practice preference. Conclusion The overwhelming preference of male and female GPs for working in group practices is apparently being met by the number of positions (principal or non-principal) available in group practices. The preference of male and female GPs regarding the type of practice and job conditions is expected to converge further in the near future. PMID:17629907

  12. Postoperative Paralysis From Thoracic Ossification of Posterior Longitudinal Ligament Surgery Risk Factor of Neurologic Injury: Nationwide Multiinstitution Survey.

    Science.gov (United States)

    Ito, Zenya; Matsuyama, Yukihiro; Ando, Muneharu; Kawabata, Shigenori; Kanchiku, Tsukasa; Kida, Kazunobu; Fujiwara, Yasushi; Yamada, Kei; Yamamoto, Naoya; Kobayashi, Sho; Saito, Takanori; Wada, Kanichiro; Tadokoro, Nobuaki; Takahashi, Masato; Satomi, Kazuhiko; Shinomiya, Kenichi; Tani, Toshikazu

    2016-10-01

    Retrospective case-control study. The purpose of this study was to examine the factors of postoperative paralysis in patients who have undergone thoracic ossification of posterior longitudinal ligament (OPLL) surgery. A higher percentage of thoracic OPLL patients experience postoperative aggravation of paralysis than cervical OPLL patients, including patients that presented great difficulties in treatment. However, there were a few reports to prevent paralysis thoracic OPLL. The 156 patients who had received thoracic OPLL surgery were selected as the subjects of this study. The items for review were the duration of disease; the preoperative muscle strength (Muscle Manual Testing); OPLL levels (T1/2-4/5: high, T5/6-8/9: middle, and T9/10-11/12: low); the spinal canal occupancy ratio; the ratio of yellow ligament ossification as a complication; the ratio of transcranial-motor evoked potential (Tc-MEP) derivation; the preoperative/postoperative kyphotic angles in the thoracic vertebrae; the correction angle of kyphosis; the duration of surgery; and the amount of bleeding. The subjects were divided into two groups based on the absence or presence of postoperative paralysis to determine the factors of postoperative paralysis. Twenty-three patients (14.7%) exhibited postoperative paralysis. Multivariate analysis identified factors associated with postoperative paralysis: the duration of disease (odds ratio, OR = 3.3); the correction angle of kyphosis (OR = 2.4); and the ratio of Tc-MEP derivation (OR = 2.2). The risk factors of postoperative paralysis are a short duration of disease and a small correction angle of kyphosis. In addition, ratios of Tc-MEP derivation below 50% may anticipate paralysis. 4.

  13. Gender shift in realisation of preferred type of gp practice: longitudinal survey over the last 25 years

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    Scherpbier Albert

    2007-07-01

    Full Text Available Abstract Background An increasing number of newly trained Dutch GPs prefer to work in a group practice and as a non-principal rather than in a single-handed practice. In view of the greater number of female doctors, changing practice preferences, and discussions on future workforce problems, the question is whether male and female GPs were able to realise their initial preferences in the past and will be able to do so in the future. Methods We have conducted longitudinal cohort study of all GPs in the Netherlands seeking a practice between 1980 and 2004. The Netherlands Institute of Health Services Research (NIVEL in Utrecht collected the data used in this study by means of a postal questionnaire. The overall mean response rate was 94%. Results Over the past 20 years, an increasing proportion of GPs, both male and female, were able to achieve their preference for working in a group practice and/or in a non-principal position. Relatively more women than men have settled in group practices, and more men than women in single-handed practices; however, the practice preference of men and women is beginning to converge. Dropout was highest among the GPs without any specific practice preference. Conclusion The overwhelming preference of male and female GPs for working in group practices is apparently being met by the number of positions (principal or non-principal available in group practices. The preference of male and female GPs regarding the type of practice and job conditions is expected to converge further in the near future.

  14. Investigating Canadian parents' HPV vaccine knowledge, attitudes and behaviour: a study protocol for a longitudinal national online survey.

    Science.gov (United States)

    Shapiro, Gilla K; Perez, Samara; Naz, Anila; Tatar, Ovidiu; Guichon, Juliet R; Amsel, Rhonda; Zimet, Gregory D; Rosberger, Zeev

    2017-10-11

    Human papillomavirus (HPV), a sexually transmitted infection, can cause anogenital warts and a number of cancers. To prevent morbidity and mortality, three vaccines have been licensed and are recommended by Canada's National Advisory Committee on Immunisation (for girls since 2007 and boys since 2012). Nevertheless, HPV vaccine coverage in Canada remains suboptimal in many regions. This study will be the first to concurrently examine the correlates of HPV vaccine decision-making in parents of school-aged girls and boys and evaluate changes in parental knowledge, attitudes and behaviours over time. Using a national, online survey utilising theoretically driven constructs and validated measures, this study will identify HPV vaccine coverage rates and correlates of vaccine decision-making in Canada at two time points (August-September 2016 and June-July 2017). 4606 participants will be recruited to participate in an online survey through a market research and polling firm using email invitations. Data cleaning methods will identify inattentive or unmotivated participants. The study received research ethics board approval from the Research Review Office, Integrated Health and Social Services University Network for West-Central Montreal (CODIM-FLP-16-219). The study will adopt a multimodal approach to disseminate the study's findings to researchers, clinicians, cancer and immunisation organisations and the public in Canada and internationally. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  15. Aging Baby Boomers and the Rising Cost of Chronic Back Pain: Secular Trend Analysis of Longitudinal Medical Expenditures Panel Survey Data for Years 2000 to 2007

    Science.gov (United States)

    Smith, Monica; Davis, Matthew A.; Stano, Miron; Whedon, James M.

    2013-01-01

    Objectives The purposes of this study were to analyze data from the longitudinal Medical Expenditures Panel Survey (MEPS) to evaluate the impact of an aging population on secular trends in back pain and chronicity and to provide estimates of treatment costs for patients who used only ambulatory services. Methods Using the MEPS 2-year longitudinal data for years 2000 to 2007, we analyzed data from all adult respondents. Of the total number of MEPS respondent records analyzed (N = 71 838), we identified 12 104 respondents with back pain and further categorized 3842 as chronic cases and 8262 as nonchronic cases. Results Secular trends from the MEPS data indicate that the prevalence of back pain has increased by 29%, whereas chronic back pain increased by 64%. The average age among all adults with back pain increased from 45.9 to 48.2 years; the average age among adults with chronic back pain increased from 48.5 to 52.2 years. Inflation-adjusted (to 2010 dollars) biennial expenditures on ambulatory services for chronic back pain increased by 129% over the same period, from $15.6 billion in 2000 to 2001 to $35.7 billion in 2006 to 2007. Conclusion The prevalence of back pain, especially chronic back pain, is increasing. To the extent that the growth in chronic back pain is caused, in part, by an aging population, the growth will likely continue or accelerate. With relatively high cost per adult with chronic back pain, total expenditures associated with back pain will correspondingly accelerate under existing treatment patterns. This carries implications for prioritizing health policy, clinical practice, and research efforts to improve care outcomes, costs, and cost-effectiveness and for health workforce planning. PMID:23380209

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

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    Steenbeek, Romy

    2012-08-31

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

  17. [Staff Satisfaction within Duty Hour Models: Longitudinal Survey on Suitability and Legal Conformity at a Surgical Maximum Care Department].

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    Langelotz, C; Koplin, G; Pascher, A; Lohmann, R; Köhler, A; Pratschke, J; Haase, O

    2017-12-01

    Background Between the conflicting requirements of clinic organisation, the European Working Time Directive, patient safety, an increasing lack of junior staff, and competitiveness, the development of ideal duty hour models is vital to ensure maximum quality of care within the legal requirements. To achieve this, it is useful to evaluate the actual effects of duty hour models on staff satisfaction. Materials and Methods After the traditional 24-hour duty shift was given up in a surgical maximum care centre in 2007, an 18-hour duty shift was implemented, followed by a 12-hour shift in 2008, to improve handovers and reduce loss of information. The effects on work organisation, quality of life and salary were analysed in an anonymous survey in 2008. The staff survey was repeated in 2014. Results With a response rate of 95% of questionnaires in 2008 and a 93% response rate in 2014, the 12-hour duty model received negative ratings due to its high duty frequency and subsequent social strain. Also the physical strain and chronic tiredness were rated as most severe in the 12-hour rota. The 18-hour duty shift was the model of choice amongst staff. The 24-hour duty model was rated as the best compromise between the requirements of work organisation and staff satisfaction, and therefore this duty model was adapted accordingly in 2015. Conclusion The essential basis of a surgical department is a duty hour model suited to the requirements of work organisation, the Working Time Directive and the needs of the surgical staff. A 12-hour duty model can be ideal for work organisation, but only if augmented with an adequate number of staff members, the implementation of this model is possible without the frequency of 12-hour shifts being too high associated with strain on surgical staff and a perceived deterioration of quality of life. A staff survey should be performed on a regular basis to assess the actual effects of duty hour models and enable further optimisation. The much

  18. Observational longitudinal study of symptom burden and time for recovery from community-acquired pneumonia reported by older adults surveyed nationwide using the CAP Burden of Illness Questionnaire

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    Wyrwich KW

    2015-07-01

    Full Text Available Kathleen W Wyrwich,1 Holly Yu,2 Reiko Sato,2 John H Powers31Evidera, Inc., Bethesda, MD, USA; 2Pfizer Inc., Collegeville, PA, USA; 3George Washington University School of Medicine and Health Sciences, Washington, DC, USABackground: Millions of older adults who develop community-acquired pneumonia (CAP each year survive, but there is a large knowledge gap on the burden of CAP and the recovery process in survivors from the patient perspective.Methods: The newly developed CAP Burden of Illness Questionnaire was administered through a Web survey to a nationwide sample of US adults aged ≥50 years who were recently diagnosed with CAP. Survey respondents with unresolved symptoms or other CAP-related health problems completed a second survey 30 days later; a third survey was completed another 30 days later by respondents with unresolved symptoms or problems. Nationally representative results describing the average time to recovery of symptoms and other CAP-related problems were achieved using post-stratification weights.Results: Five hundred participants completed the initial survey. The time to resolution for the CAP symptoms of weakness, shortness of breath, and tiredness exceeded 3 weeks on average. There was an average of 13 days of absenteeism, and 3 weeks (mean =21 days before achieving full work/activity productivity after CAP. For participants with health conditions that worsened from pneumonia, chronic emphysema and chronic obstructive pulmonary disease took the longest to return to baseline (mean =60 and 52.4 days, respectively.Conclusion: The results from this study demonstrate that older adults surviving a CAP episode experience a significant multi-symptom illness with long recovery periods to achieve pre-CAP health and productivity. These findings highlight the need for further research on effective clinician–patient communication, the need for patient-centered outcomes in clinical trials for CAP therapeutics, adequate home care during

  19. Trends in injury morbidity in China, 1993-2013: A longitudinal analysis of population-based survey data.

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    Ning, Peishan; Cai, Min; Cheng, Peixia; Zhang, Yaoguang; Schwebel, David C; Yang, Yang; Zhang, Wei; Cheng, Xunjie; Gao, Yuyan; Ling, Xu; Hu, Guoqing

    2018-04-01

    Understanding long-term trends in injury morbidity is critical to prevention and intervention planning. The aim of this study was to assess long-term trends in injury morbidity rates in China from 1993 to 2013. Using data from the National Health Service Survey (NHSS), which is conducted every five years, crude and age-standardized prevalence during the previous two weeks and hospitalization rates in the last 12 months with 95% confidence intervals (CI) were calculated. The Rao-Scott Chi-square test examined injury morbidity differences across the five survey years by location (urban/rural), sex, age group, and household income. Percent changes in morbidity rate were approximated using logistic regressions. Sampling weights were applied to all analyses. In 2013, crude two-week injury prevalence in China was 0.46% (95% CI: 0.40%, 0.52%) and 12-month crude hospitalization rate was 0.70% (95% CI: 0.63%, 0.77%). Age-standardized injury prevalence increased 31.4% (95% CI: 7.6%, 60.6%) between 1993 and 2013 (29.4%, 95% CI: 6.7%, 56.9% from 1993-2003; 1.6%, 95% CI: -14.8%, 21.0% from 2003-2013), and age-standardized hospitalization rates rose 107.2% (95% CI: 75.1%, 145.2%) from 1993 to 2013 (-9.5%, 95% CI: -24.6%, 8.6% from 1993-2003 and 129.0%, 95% CI: 93.9%, 170.4% from 2003-2013). Subgroup analyses showed similar trends over time. The leading cause of injury was dislocation, sprain or strain for prevalence, and fractures for hospitalization. In conclusion, injury morbidity increased substantially from 1993 to 2013 in China. Inconsistent changes in two-week prevalence and 12-month hospitalization rate merit attention from researchers and policy-makers. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Do Veterans With Posttraumatic Stress Disorder Receive First-Line Pharmacotherapy? Results From the Longitudinal Veterans Health Survey

    Science.gov (United States)

    Greenbaum, Mark A.; Rosen, Craig S.

    2012-01-01

    Objective: Guidelines addressing the treatment of veterans with posttraumatic stress disorder (PTSD) strongly recommend a therapeutic trial of selective serotonin reuptake inhibitors (SSRIs) or serotonin-norepinephrine reuptake inhibitors (SNRIs). This study examined veteran characteristics associated with receiving such first-line pharmacotherapy, as well as how being a veteran of the recent conflicts in Afghanistan and Iraq impact receipt of pharmacotherapy for PTSD. Method: This was a national study of 482 Veterans Affairs (VA) outpatients between the ages of 18 and 69 years who had been newly diagnosed with PTSD (DSM-IV criteria: 309.81) during a VA outpatient visit between May 31, 2006, and December 7, 2007. Participants completed a mailed survey between August 11, 2006, and April 6, 2008. Veterans from the Afghanistan and Iraq conflicts and female veterans were intentionally oversampled. Logistic regression models were developed to predict 2 dependent variables: odds of initiating an SSRI/SNRI and, among veterans who initiated an SSRI/SNRI, odds of receiving an adequate therapeutic trial. Each dependent variable was regressed on a variety of sociodemographic and survey characteristics. Results: Of the 377 veterans prescribed a psychotropic medication, 73% (n = 276) received an SSRI/SNRI, of whom 61% (n = 168) received a therapeutic trial. Afghanistan and Iraq veterans were less likely to receive a therapeutic trial (odds ratio [OR] = 0.45; 95% CI, 0.27–0.75; P < .01), with presence of a comorbid depression diagnosis in the year after the index episode moderating this relationship, which further decreased the odds of completing a therapeutic trial (OR = 0.29; 95% CI, 0.09–0.95; P < .05). Conclusions: Reduced levels of receipt of first-line pharmacotherapy among recent veteran returnees parallel previous findings of less mental health treatment utilization in this population and warrant investigation. PMID:22943028

  1. Comparison of generalized estimating equations and quadratic inference functions using data from the National Longitudinal Survey of Children and Youth (NLSCY database

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    Browne Dillon

    2008-05-01

    Full Text Available Abstract Background The generalized estimating equations (GEE technique is often used in longitudinal data modeling, where investigators are interested in population-averaged effects of covariates on responses of interest. GEE involves specifying a model relating covariates to outcomes and a plausible correlation structure between responses at different time periods. While GEE parameter estimates are consistent irrespective of the true underlying correlation structure, the method has some limitations that include challenges with model selection due to lack of absolute goodness-of-fit tests to aid comparisons among several plausible models. The quadratic inference functions (QIF method extends the capabilities of GEE, while also addressing some GEE limitations. Methods We conducted a comparative study between GEE and QIF via an illustrative example, using data from the "National Longitudinal Survey of Children and Youth (NLSCY" database. The NLSCY dataset consists of long-term, population based survey data collected since 1994, and is designed to evaluate the determinants of developmental outcomes in Canadian children. We modeled the relationship between hyperactivity-inattention and gender, age, family functioning, maternal depression symptoms, household income adequacy, maternal immigration status and maternal educational level using GEE and QIF. Basis for comparison include: (1 ease of model selection; (2 sensitivity of results to different working correlation matrices; and (3 efficiency of parameter estimates. Results The sample included 795, 858 respondents (50.3% male; 12% immigrant; 6% from dysfunctional families. QIF analysis reveals that gender (male (odds ratio [OR] = 1.73; 95% confidence interval [CI] = 1.10 to 2.71, family dysfunctional (OR = 2.84, 95% CI of 1.58 to 5.11, and maternal depression (OR = 2.49, 95% CI of 1.60 to 2.60 are significantly associated with higher odds of hyperactivity-inattention. The results remained robust

  2. Within-person analysis of welfare transitions in a longitudinal panel survey reveals change in mental health service use.

    Science.gov (United States)

    Pymont, C; Schofield, T P; Butterworth, P

    2017-12-01

    While international research shows that receipt of welfare benefits is associated with poor mental health, less is known about the relationship between welfare receipt and mental health service use. We investigate whether within-person change in welfare recipient status is associated with change in mental health service use. Analysis of two waves of data from an Australian national household survey. Random- and fixed-effect models considered the effect of change in welfare receipt status, and assessed whether change in mental health service use differed by type of welfare benefit or the direction of welfare transition. Individuals were more likely to report greater mental health service use at times of welfare receipt. These associations were attenuated, but remained significant, after adjusting for mental health. Increased health service use was not tied to specific types of welfare benefits. The increase in mental health service use associated with a transition onto welfare benefits was much greater than the decline in service use associated with the transition off benefits. Within individuals, welfare receipt is associated with greater mental health service use. While this does reflect poorer mental health at the time of welfare receipt, other factors seem to facilitate health service use. © The Author 2016. Published by Oxford University Press on behalf of Faculty of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  3. Incidence of self-reported brain injury and the relationship with substance abuse: findings from a longitudinal community survey

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    Butterworth Peter

    2010-03-01

    Full Text Available Abstract Background Traumatic or serious brain injury (BI has persistent and well documented adverse outcomes, yet 'mild' or 'moderate' BI, which often does not result in hospital treatment, accounts for half the total days of disability attributed to BI. There are currently few data available from community samples on the incidence and correlates of these injuries. Therefore, the study aimed to assess the 1 incidence of self-reported mild (not requiring hospital admission and moderate (admitted to hospital brain injury (BI, 2 causes of injury 3 physical health scores and 4 relationship between BI and problematic alcohol or marijuana use. Methods An Australian community sequential-cohort study (cohorts aged 20-24, 40-44 and 60-64 years at wave one used a survey methodology to assess BI and substance use at baseline and four years later. Results Of the 7485 wave one participants, 89.7% were re-interviewed at wave two. There were 56 mild (230.8/100000 person-years and 44 moderate BI (180.5/100000 person-years reported between waves one and two. Males and those in the 20-24 year cohort had increased risk of BI. Sports injury was the most frequent cause of BI (40/100 with traffic accidents being a greater proportion of moderate (27% than mild (7% BI. Neither alcohol nor marijuana problems at wave one were predictors of BI. BI was not a predictor of developing substance use problems by wave two. Conclusions BI were prevalent in this community sample, though the incidence declined with age. Factors associated with BI in community samples differ from those reported in clinical samples (e.g. typically traumatic brain injury with traffic accidents the predominate cause. Further, detailed evaluation of the health consequences of these injuries is warranted.

  4. Access to health-care in Canadian immigrants: a longitudinal study of the National Population Health Survey.

    Science.gov (United States)

    Setia, Maninder Singh; Quesnel-Vallee, Amelie; Abrahamowicz, Michal; Tousignant, Pierre; Lynch, John

    2011-01-01

    Immigrants often lose their health advantage as they start adapting to the ways of the new society. Having access to care when it is needed is one way that individuals can maintain their health. We assessed the healthcare access in Canadian immigrants and the socioeconomic factors associated with access over a 12-year period. We compared two measures of healthcare access (having a regular doctor and reporting an unmet healthcare need in the past 12 months) among immigrants and Canadian-born men and women, aged more than 18 years. We applied a logistic random effects model to evaluate these outcomes separately, in 3081 males and 4187 females from the National Population Health Survey (1994-2006). Adjusting for all covariates, immigrant men and women (white and non-white) had similar odds of having a regular doctor than the Canadian-born individuals (white immigrants: males OR: 1.32, 95% C.I.: 0.89-1.94, females OR: 1.14, 95% C.I.: 0.78-1.66; non-white immigrants: males OR: 1.28, 95% C.I.: 0.73-2.23, females OR: 1.23, 95% C.I.: 0.64-2.36). Interestingly, non-white immigrant women had significantly fewer unmet health needs (OR: 0.32, 95% C.I.: 0.17-0.59). Among immigrants, time since immigration was associated with having access to a regular doctor (OR per year: 1.02, 95% C.I.: 1.00-1.04). Visible minority female immigrants were least likely to report an unmet healthcare need. In general, there is little evidence that immigrants have worse access to health-care than the Canadian-born population. © 2010 Blackwell Publishing Ltd.

  5. Tax, price and cigarette brand preferences: a longitudinal study of adult smokers from the ITC Mexico Survey.

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    Sáenz de Miera Juárez, Belén; Thrasher, James F; Reynales Shigematsu, Luz Myriam; Hernández Ávila, Mauricio; Chaloupka, Frank J

    2014-03-01

    Recent tax increases in Mexico differed in structure and provided an opportunity to better understand tobacco industry pricing strategies, as well as smokers' responses to any resulting price changes. To assess if taxes were passed onto consumers of different cigarette brands, the extent of brand switching and predictors of preference for cheaper national brands. Using data from three waves of the Mexican administration of the International Tobacco Control Survey, we analysed self-reported brand and price paid at last cigarette purchase. Generalised estimating equations were used to determine predictors of price and preference for national brands. The average price of premium/international brands increased each year from 2008 to 2011; however, the price for discount/national brands increased only from 2010 to 2011. The percentage of smokers who smoked national brands remained stable between 2008 and 2010 but dropped in 2011. Factors related to smoking national brands as opposed to international brands included being male and having relatively older age, lower education, lower income and higher consumption. Tobacco industry pricing strategies in the wake of ad valorem taxes implemented in Mexico prior to 2011 had the impact of segmenting the market into discount national brands and premium international brands. The specific tax increase implemented in 2011 reduced the price gap between these two segments by raising the price of the national brands relative to the international brands. Evidence for trading up was found after the 2011 tax increase. These results provide further evidence for the relevance of tax policy as a tobacco control strategy; in particular, they illustrate the importance of how specific rather than ad valorem taxes can reduce the potential for downward brand switching in the face of decreasing cigarette affordability.

  6. Are Immigrants More Physically Active Than Native-Born Australians and Does it Changes Over Time? Evidence From a Nationally Representative Longitudinal Survey.

    Science.gov (United States)

    Joshi, Suresh; Jatrana, Santosh; Paradies, Yin

    2017-02-01

    We investigated the differences and over time changes in recommended physical activity among foreign-born (FB) from English speaking countries (ESC) and non-English speaking countries (NESC) relative to native-born (NB) Australians, and whether the association between nativity and duration of residence (DoR) and physical activity is mediated by English language proficiency, socioeconomic status and social engagement/membership. This study applies multilevel group-meancentered mixed (hybrid) logistic regression models to 12 waves of longitudinal data (12,634 individuals) from the Household, Income and Labor Dynamics in Australia survey with engagement in physical activities for more than 3 times a week as the outcome variable. Immigrants from ESC had higher odds of physical activity, while immigrants from NESC had significantly lower odds of physical activity than NB Australians, after adjusting for covariates. There was no evidence that these differences changed by DoR among immigrants from NESC, whereas ESC immigrants had higher odds of physical activity when their DoR was more than 20 years. We also found a mediating role of English language proficiency on immigrants physical activities. Appropriate health promotion interventions should be implemented to foster physical activities among NESC immigrants, considering English language proficiency as an important factor in designing interventions.

  7. Does more education cause lower BMI, or do lower-BMI individuals become more educated? Evidence from the National Longitudinal Survey of Youth 1979.

    Science.gov (United States)

    Benson, Rebecca; von Hippel, Paul T; Lynch, Jamie L

    2017-03-21

    More educated adults have lower average body mass index (BMI). This may be due to selection, if adolescents with lower BMI attain higher levels of education, or it may be due to causation, if higher educational attainment reduces BMI gain in adulthood. We test for selection and causation in the National Longitudinal Survey of Youth 1979, which has followed a representative US cohort from age 14-22 in 1979 through age 47-55 in 2012. Using ordinal logistic regression, we test the selection hypothesis that overweight and obese adolescents were less likely to earn high school diplomas and bachelor's degrees. Then, controlling for selection with individual fixed effects, we estimate the causal effect of degree completion on BMI and obesity status. Among 18-year-old women, but not among men, being overweight or obese predicts lower odds of attaining higher levels of education. At age 47-48, higher education is associated with lower BMI, but 70-90% of the association is due to selection. Net of selection, a bachelor's degree predicts less than a 1 kg reduction in body weight, and a high school credential does not reduce BMI. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. The Impact of Leisure and Social Activities on Activities of Daily Living of Middle-Aged Adults: Evidence from a National Longitudinal Survey in Japan.

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    Takafumi Monma

    Full Text Available This study investigated the effects of leisure and social activities on the ability of middle-aged adults to maintain activities of daily living (ADL, and whether performing these activities alone or with others contributed to the ability to perform ADL. The study used nationally representative longitudinal data of 22,770 adults in Japan, aged 50-59 years, who did not have limitations in performing ADL at the beginning of the 5-year survey period. The study considered six activity categories: two leisure activities ("hobbies or cultural activities" and "exercise or sports" and four social activities ("community events," "support for children," "support for elderly individuals," and "other social activities". Multiple logistic regression analysis was used to examine the relation between participation in these categories at baseline and difficulties in ADL at the 5-year follow-up. The association between the extent of social interaction during these activities ("by oneself," "with others," or "both" and difficulties in ADL was also investigated. The analysis yielded significant negative correlations between "exercise or sports" and difficulties in ADL for both men and women, and between "hobbies or cultural activities" and difficulties in ADL for women. However, these significant relationships occurred only when activities were conducted "with others." The present findings might help prevent deterioration in middle-aged adults' performance of ADL in Japan.

  9. Assessing the Contribution of Unstable Employment to Mortality in Posttransition Russia: Prospective Individual-Level Analyses From the Russian Longitudinal Monitoring Survey

    Science.gov (United States)

    Bobak, Martin

    2009-01-01

    Objectives. We used the Russia Longitudinal Monitoring Survey (RLMS) to investigate associations between employment, socioeconomic position, and mortality. Methods. Data were from working-age respondents in 8 rounds (1994–2003) of the RLMS. We measured associations between education, occupation, unemployment, and insecure employment and mortality with Cox proportional hazards analyses. Results. Of 4465 men and 4158 women who were currently employed, 251 men and 34 women died. A third of employed respondents experienced wage arrears, and 10% experienced compulsory leave and payment in consumer goods. Insecure employment, more common among the less-educated and manual workers, fluctuated with macroeconomic measures. Mortality was significantly associated with payment in consumer goods among men (hazard ratio [HR] = 1.46; 95% confidence interval [CI] = 1.03, 2.07), compulsory unpaid leave among women (HR = 3.79; 95% CI = 1.82, 7.88), and male unemployment (HR = 1.88; 95% CI = 1.38, 2.55). Associations with death within 1 year of entry were generally somewhat stronger than the association with mortality over the whole study period. Conclusions. Unemployment and job insecurity predicted mortality, suggesting that they contributed to Russia's high mortality during the transition from communism. PMID:19696378

  10. Longitudinal Associations of Leisure-Time Physical Activity and Cancer Mortality in the Third National Health and Nutrition Examination Survey (1986–2006

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    Niyati Parekh

    2012-01-01

    Full Text Available Longitudinal associations between leisure-time physical activity (LTPA and overall cancer mortality were evaluated within the Third National Health and Nutrition Examination Survey (NHANES III; 1988–2006; n=15,535. Mortality status was ascertained using the National Death Index. Self-reported LTPA was divided into inactive, regular low-to-moderate and vigorous activity. A frequency-weighted metabolic equivalents (METS/week variable was also computed. Hazard ratios (HRs and 95% confidence intervals (CI were calculated for overall cancer mortality in the whole sample, by body mass index categories and insulin resistance (IR status. Nonsignificant protective associations were observed for regular low-to-moderate and vigorous activity, and for the highest quartile of METS/week (HRs range: 0.66–0.95. Individuals without IR engaging in regular vigorous activity had a 48% decreased risk of cancer mortality (HR: 0.52; 95% CI: 0.28–0.98 in multivariate analyses. Conversely, nonsignificant positive associations were observed in people with IR. In conclusion, regular vigorous activity may reduce risk of cancer mortality among persons with normal insulin-glucose metabolism in this national sample.

  11. Do Predictors of Career Success Differ between Swedish Women and Men? Data from the Swedish Longitudinal Occupational Survey of Health (SLOSH).

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    Nyberg, Anna; Magnusson Hanson, Linda L; Leineweber, Constanze; Johansson, Gunn

    2015-01-01

    The aim of this prospective study was to explore predictors of objective career success among Swedish women and men, focussing on gender differences. Data were drawn from the 2008 and 2010 waves of the Swedish Longitudinal Occupational Survey of Health (SLOSH) with a total of 3670 female and 2773 male participants. Odds ratios and 95% confidence intervals for job promotion and an above-average salary increase between 2008 and 2010 were obtained through binary logistic regression analyses. Individual and organisational factors measured in 2008 were used as predictors in analyses stratified by sex. Mutual adjustment was performed for these variables, as well as for labour market sector and staff category at baseline. In both sexes, younger age predicted both job promotion and an above-average salary increase. Job promotion was also in both sexes predicted by being part of decision-making processes, having conflicts with superiors, and being eager to advance. Furthermore, promotion was predicted by, among men, being educated to post-graduate level and having an open coping strategy and, among women, working >60 hours/week. An above-average salary increase was predicted in both sexes by having a university education. Postgraduate education, having children living at home, and being very motivated to advance predicted an above-average salary increase among women, as did working 51-60 hours/week and being part of decision-making processes in men. Gender differences were seen in several predictors. In conclusion, the results support previous findings of gender differences in predictors of career success. A high level of education, motivation to advance, and procedural justice appear to be more important predictors of career success among women, while open coping was a more important predictor among men.

  12. Women's Longitudinal Patterns of Smoking during the Pre-Conception, Pregnancy and Postnatal Period: Evidence from the UK Infant Feeding Survey.

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    Kate E Fitzpatrick

    Full Text Available An understanding of women's longitudinal patterns of smoking during the pre-conception, pregnancy and postnatal period and the factors associated with these patterns could help better inform smoking cessation services and interventions.Latent class analysis (LCA was used to empirically identify women's smoking patterns in a sample of 10,768 mothers from the 2010 UK Infant Feeding Survey. Multinomial logistic regression was used to identify characteristics associated with these patterns.LCA identified five distinct smoking patterns during the pre-conception, pregnancy and postnatal period: "non-smokers" (74.1% of women; "pregnancy-inspired quitters" (10.2%; "persistent smokers" (10.1%; "temporary quitters" (4.4%; and postnatal quitters (1.1%. Smoking patterns varied markedly according to socio-demographic variables and parity. After adjusting for these variables, mothers who lived during pregnancy with a partner who smoked were more likely to be temporary quitters (aOR 2.64, 95% CI 1.74-3.99 or persistent smokers (aOR 3.32, 95% CI 2.34-4.72 than pregnancy-inspired quitters. Mothers who lived during pregnancy with someone else other than a partner who smoked were more likely to be persistent smokers (aOR 2.34, 95% CI 1.38-3.97 or postnatal quitters (aOR 2.97, 95% CI 1.07-8.24 than pregnancy-inspired quitters. Mothers given information on how their partner could stop smoking if they lived during pregnancy with a smoking partner were less likely to be persistent smokers (aOR 0.42, 95% CI 0.27-0.65 than pregnancy-inspired quitters.Health professionals should ask about smoking at every opportunity, and refer women who self-report as current smokers to an evidence based smoking cessation service.

  13. How Possibly Do Leisure and Social Activities Impact Mental Health of Middle-Aged Adults in Japan?: An Evidence from a National Longitudinal Survey.

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    Fumi Takeda

    Full Text Available This study aimed to investigate longitudinal relations between leisure and social activities and mental health status, considering the presence or absence of other persons in the activity as an additional variable, among middle-aged adults in Japan. This study used nationally representative data in Japan with a five-year follow-up period.This study focused on 16,642 middle-aged adults, age 50-59 at baseline, from a population-based, six-year panel survey conducted by the Japanese Ministry of Health, Labour and Welfare. To investigate the relations between two leisure activities ('hobbies or cultural activities' and 'exercise or sports' and four social activities ('community events', 'support for children', 'support for elderly individuals' and 'other social activities' at baseline and mental health status at follow-up, multiple logistic regression analysis was used. We also used multiple logistic regression analysis to investigate the association between ways of participating in these activities ('by oneself', 'with others', or 'both' (both 'by oneself' and 'with others' at baseline and mental health status at follow-up.Involvement in both leisure activity categories, but not in social activities, was significantly and positively related to mental health status in both men and women. Furthermore, in men, both 'hobbies or cultural activities' and 'exercise or sports' were significantly related to mental health status only when conducted 'with others'. In women, the effects of 'hobbies or cultural activities' on mental health status were no differences regardless of the ways of participating, while the result of 'exercise or sports' was same as that in men.Leisure activities appear to benefit mental health status among this age group, whereas specific social activities do not. Moreover, participation in leisure activities would be effective especially if others are present. These findings should be useful for preventing the deterioration of mental

  14. The Impact of Leisure and Social Activities on Activities of Daily Living of Middle-Aged Adults: Evidence from a National Longitudinal Survey in Japan

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    Monma, Takafumi; Takeda, Fumi; Noguchi, Haruko; Takahashi, Hideto; Tamiya, Nanako

    2016-01-01

    This study investigated the effects of leisure and social activities on the ability of middle-aged adults to maintain activities of daily living (ADL), and whether performing these activities alone or with others contributed to the ability to perform ADL. The study used nationally representative longitudinal data of 22,770 adults in Japan, aged 50–59 years, who did not have limitations in performing ADL at the beginning of the 5-year survey period. The study considered six activity categories: two leisure activities (“hobbies or cultural activities” and “exercise or sports”) and four social activities (“community events,” “support for children,” “support for elderly individuals,” and “other social activities”). Multiple logistic regression analysis was used to examine the relation between participation in these categories at baseline and difficulties in ADL at the 5-year follow-up. The association between the extent of social interaction during these activities (“by oneself,” “with others,” or “both”) and difficulties in ADL was also investigated. The analysis yielded significant negative correlations between “exercise or sports” and difficulties in ADL for both men and women, and between “hobbies or cultural activities” and difficulties in ADL for women. However, these significant relationships occurred only when activities were conducted “with others.” The present findings might help prevent deterioration in middle-aged adults’ performance of ADL in Japan. PMID:27788163

  15. How Possibly Do Leisure and Social Activities Impact Mental Health of Middle-Aged Adults in Japan?: An Evidence from a National Longitudinal Survey.

    Science.gov (United States)

    Takeda, Fumi; Noguchi, Haruko; Monma, Takafumi; Tamiya, Nanako

    2015-01-01

    This study aimed to investigate longitudinal relations between leisure and social activities and mental health status, considering the presence or absence of other persons in the activity as an additional variable, among middle-aged adults in Japan. This study used nationally representative data in Japan with a five-year follow-up period. This study focused on 16,642 middle-aged adults, age 50-59 at baseline, from a population-based, six-year panel survey conducted by the Japanese Ministry of Health, Labour and Welfare. To investigate the relations between two leisure activities ('hobbies or cultural activities' and 'exercise or sports') and four social activities ('community events', 'support for children', 'support for elderly individuals' and 'other social activities') at baseline and mental health status at follow-up, multiple logistic regression analysis was used. We also used multiple logistic regression analysis to investigate the association between ways of participating in these activities ('by oneself', 'with others', or 'both' (both 'by oneself' and 'with others')) at baseline and mental health status at follow-up. Involvement in both leisure activity categories, but not in social activities, was significantly and positively related to mental health status in both men and women. Furthermore, in men, both 'hobbies or cultural activities' and 'exercise or sports' were significantly related to mental health status only when conducted 'with others'. In women, the effects of 'hobbies or cultural activities' on mental health status were no differences regardless of the ways of participating, while the result of 'exercise or sports' was same as that in men. Leisure activities appear to benefit mental health status among this age group, whereas specific social activities do not. Moreover, participation in leisure activities would be effective especially if others are present. These findings should be useful for preventing the deterioration of mental health

  16. Do Predictors of Career Success Differ between Swedish Women and Men? Data from the Swedish Longitudinal Occupational Survey of Health (SLOSH.

    Directory of Open Access Journals (Sweden)

    Anna Nyberg

    Full Text Available The aim of this prospective study was to explore predictors of objective career success among Swedish women and men, focussing on gender differences. Data were drawn from the 2008 and 2010 waves of the Swedish Longitudinal Occupational Survey of Health (SLOSH with a total of 3670 female and 2773 male participants. Odds ratios and 95% confidence intervals for job promotion and an above-average salary increase between 2008 and 2010 were obtained through binary logistic regression analyses. Individual and organisational factors measured in 2008 were used as predictors in analyses stratified by sex. Mutual adjustment was performed for these variables, as well as for labour market sector and staff category at baseline. In both sexes, younger age predicted both job promotion and an above-average salary increase. Job promotion was also in both sexes predicted by being part of decision-making processes, having conflicts with superiors, and being eager to advance. Furthermore, promotion was predicted by, among men, being educated to post-graduate level and having an open coping strategy and, among women, working >60 hours/week. An above-average salary increase was predicted in both sexes by having a university education. Postgraduate education, having children living at home, and being very motivated to advance predicted an above-average salary increase among women, as did working 51-60 hours/week and being part of decision-making processes in men. Gender differences were seen in several predictors. In conclusion, the results support previous findings of gender differences in predictors of career success. A high level of education, motivation to advance, and procedural justice appear to be more important predictors of career success among women, while open coping was a more important predictor among men.

  17. Different outcomes for different health measures in immigrants: evidence from a longitudinal analysis of the National Population Health Survey (1994-2006).

    Science.gov (United States)

    Setia, Maninder Singh; Quesnel-Vallee, Amelie; Abrahamowicz, Michal; Tousignant, Pierre; Lynch, John

    2012-02-01

    The response of immigrants to new societies is dynamic. There may be an initial period of happiness followed by peaks of stressful periods. These reactions along with socio-economic changes are likely to influence their health, which may start converging towards the average health of the host population. We used a longitudinal analysis to assess the differences in health outcomes (mental health and self-rated health), separately in men and women, in Canadian born and immigrants over a 12-year period (and the associated socio-economic factors). We used random effects logistic regression models for evaluation of these health outcomes in 3,081 men and 4,187 women from the National Population Health Survey (1994/95 to 2006/07). After adjusting for all the covariates, non-white immigrants were less likely to have severe psychological distress compared with the Canadian born individuals [odds ratio (OR) Men: 0.49, 95% confidence intervals (CI) 0.24-1.00, Women-OR: 0.54; 95% CI: 0.32-0.92]. Immigrant women (white and non-white) were more likely to rate their health as poor through this 12-year period than the Canadian born women (White-OR: 1.64, 95% CI: 1.17-2.64; Non-white-OR: 1.82, 95% CI: 1.01-3.28). Immigrants in the lowest income adequacy category reported higher psychological distress and poorer health than those in the highest income categories. We did not find any significant differences in the mental health and self-rated health of Canadian men and white male immigrants throughout this 12-year period. Though, non-white immigrant women were less likely to have severe psychological distress through this 12 year period, they were the ones most likely to rate their health as poor.

  18. The "Medicine in Australia: Balancing Employment and Life (MABEL" longitudinal survey - Protocol and baseline data for a prospective cohort study of Australian doctors' workforce participation

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    Witt Julia

    2010-02-01

    Full Text Available Abstract Background While there is considerable research on medical workforce supply trends, there is little research examining the determinants of labour supply decisions for the medical workforce. The "Medicine in Australia: Balancing Employment and Life (MABEL" study investigates workforce participation patterns and their determinants using a longitudinal survey of Australian doctors. It aims to generate evidence to support developing effective policy responses to workforce issues such as shortages and maldistribution. This paper describes the study protocol and baseline cohort, including an analysis of response rates and response bias. Methods/Design MABEL is a prospective cohort study. All Australian doctors undertaking clinical work in 2008 (n = 54,750 were invited to participate, and annual waves of data collections will be undertaken until at least 2011. Data are collected by paper or optional online version of a questionnaire, with content tailored to four sub-groups of clinicians: general practitioners, specialists, specialists in training, and hospital non-specialists. In the baseline wave, data were collected on: job satisfaction, attitudes to work and intentions to quit or change hours worked; a discrete choice experiment examining preferences and trade-offs for different types of jobs; work setting; workload; finances; geographic location; demographics; and family circumstances. Discussion The baseline cohort includes 10,498 Australian doctors, representing an overall response rate of 19.36%. This includes 3,906 general practitioners, 4,596 specialists, 1,072 specialists in training, and 924 hospital non-specialists. Respondents were more likely to be younger, female, and to come from non-metropolitan areas, the latter partly reflecting the effect of a financial incentive on response for doctors in remote and rural areas. Specialists and specialists in training were more likely to respond, whilst hospital non-specialists were less

  19. Swiss community pharmacies' on the Web and pharmacists' experiences with E-commerce: longitudinal study and Internet-based questionnaire survey.

    Science.gov (United States)

    Zehnder, Simon; Bruppacher, Rudolf; Ruppanner, Hans; Hersberger, Kurt E

    2004-03-03

    There are multiple ways in which community pharmacies can present themselves on the Internet, e.g., as a platform for drug information or as an advertising platform for their services. To estimate the number of Swiss community pharmacies on the Internet over the period of 32 months (2000-2003), to describe their current e-commerce services, and to explore the experiences and plans these pharmacies have with regard to their Internet presence. A longitudinal study was performed to determine the number of Swiss German pharmacies on the Internet by conducting Internet searches in 2000, 2001, and 2003. In April 2002, a cross-sectional Internet-based survey was administered to explore the pharmacies' experiences and plans regarding their Web sites. As of April 2003, 373 (44%) of 852 community pharmacies from the German speaking part of Switzerland were on the Internet. One hundred eighty four listed an e-mail address and were asked to complete a questionnaire. Of the 107 pharmacies answering the survey questions (58% response rate): 46% had been on the Internet for 1 to 2 years; 33% of the Web sites are part of a pharmacy group's Web portal; 31% of the pharmacies plan to expand their Internet appearance in the future; 74% provide e-commerce services, with 81% of those pharmacies filling five or less orders per month; and 12% plan on expanding their e-commerce services in the future. The number of community pharmacies offering Internet services steadily increased over 32 months. Given the importance of the Internet as a tool for information, communication, and advertising for pharmacy products and services, it can be expected that the increase will continue. Pharmacy-group portals are important promoters of pharmacies on the Internet. For many community pharmacies, Internet portals that provide an Internet presence for the pharmacies and provide regularly-updated content (e.g., health news, tips, drug information) seem to be the most effective solutions. Even though 40

  20. Swiss Community Pharmacies' on the Web and Pharmacists' Experiences with E-commerce: Longitudinal study and Internet-based questionnaire survey

    Science.gov (United States)

    Bruppacher, Rudolf; Ruppanner, Hans; Hersberger, Kurt E

    2004-01-01

    Background There are multiple ways in which community pharmacies can present themselves on the Internet, e.g., as a platform for drug information or as an advertising platform for their services. Objective To estimate the number of Swiss community pharmacies on the Internet over the period of 32 months (2000-2003), to describe their current e-commerce services, and to explore the experiences and plans these pharmacies have with regard to their Internet presence. Methods A longitudinal study was performed to determine the number of Swiss German pharmacies on the Internet by conducting Internet searches in 2000, 2001, and 2003. In April 2002, a cross-sectional Internet-based survey was administered to explore the pharmacies' experiences and plans regarding their Web sites. Results As of April 2003, 373 (44%) of 852 community pharmacies from the German speaking part of Switzerland were on the Internet. One hundred eighty four listed an e-mail address and were asked to complete a questionnaire. Of the 107 pharmacies answering the survey questions (58% response rate): 46% had been on the Internet for 1 to 2 years; 33% of the Web sites are part of a pharmacy group's Web portal; 31% of the pharmacies plan to expand their Internet appearance in the future; 74% provide e-commerce services, with 81% of those pharmacies filling five or less orders per month; and 12% plan on expanding their e-commerce services in the future. Conclusions The number of community pharmacies offering Internet services steadily increased over 32 months. Given the importance of the Internet as a tool for information, communication, and advertising for pharmacy products and services, it can be expected that the increase will continue. Pharmacy-group portals are important promoters of pharmacies on the Internet. For many community pharmacies, Internet portals that provide an Internet presence for the pharmacies and provide regularly-updated content (e.g., health news, tips, drug information) seem to

  1. The Epidemiology of Chronic Pain in Canadian Men and Women between 1994 and 2007: Results from the Longitudinal Component of the National Population Health Survey

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    Michelle L Reitsma

    2012-01-01

    Full Text Available BACKGROUND: The epidemiology of chronic pain is poorly understood due to a paucity of longitudinal studies limiting the ability to develop prevention strategies for a condition resistant to many current therapies.

  2. The Tokyo Oldest Old Survey on Total Health (TOOTH: A longitudinal cohort study of multidimensional components of health and well-being

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    Gondo Yasuyuki

    2010-06-01

    Full Text Available Abstract Background With the rapid worldwide increase in the oldest old population, considerable concern has arisen about the social and economic burden of diseases and disability in this age group. Understanding of multidimensional structure of health and its life-course trajectory is an essential prerequisite for effective health care delivery. Therefore, we organized an interdisciplinary research team consisting of geriatricians, dentists, psychologists, sociologists, and epidemiologists to conduct a longitudinal observational study. Methods/Design For the Tokyo Oldest Old Survey on Total Health (TOOTH study, a random sample of inhabitants of the city of Tokyo, aged 85 years or older, was drawn from the basic city registry. The baseline comprehensive assessment consists of an in-home interview, a self-administered questionnaire, and a medical/dental examination. To perform a wide variety of biomedical measurements, including carotid ultrasonography and a detailed dental examination, participants were invited to our study center at Keio University Hospital. For those who were not able to visit the study center, we provided the option of a home-based examination, in which participants were simultaneously visited by a geriatrician and a dentist. Of 2875 eligible individuals, a total of 1152 people were recruited, of which 542 completed both the in-home interview and the medical/dental examination, with 442 completed the in-home interview only, and another 168 completed self or proxy-administered data collection only. Carotid ultrasonography was completed in 458 subjects, which was 99.6% of the clinic visitors (n = 460. Masticatory assessment using a colour-changeable chewing gum was completed in 421 subjects, a 91.5% of the clinic visitors. Discussion Our results demonstrated the feasibility of a new comprehensive study that incorporated non-invasive measurements of subclinical diseases and a detailed dental examination aiming at community

  3. Serological investigation to identify risk factors for post-flood infectious diseases: a longitudinal survey among people displaced by Typhoon Morakot in Taiwan.

    Science.gov (United States)

    Lin, Chun-Yu; Chen, Tun-Chieh; Dai, Chia-Yen; Yu, Ming-Lung; Lu, Po-Liang; Yen, Jeng-Hsien; Chen, Yen-Hsu

    2015-05-14

    After Typhoon Morakot struck Taiwan in 2009, thousands of Taiwanese citizens were displaced to shelters for several weeks. Others were placed in urban communities where they had family members. This study aimed to investigate serological status in both groups and identify risk factors associated with seroconversion of infectious diseases. A longitudinal survey. All experimental and clinical investigations were performed in a tertiary teaching hospital. A total of 288 displaced persons (96 males and 192 females) were recruited and complete follow-up data through two rounds of sampling were collected. The average age was 58.42 years (range 31-87 years). First, serum specimens were collected between December 2009 and January 2010, 4-5 months after the typhoon. The second round of specimen collection was carried out after 6 months. The primary outcome measured was serological status of vaccine-preventable droplet-borne infectious diseases (ie, measles, mumps, rubella) and water-borne diseases (ie, amoebiasis and leptospirosis). The secondary outcome was identification of risk factors for seroconversion using univariate and multivariate analyses. Complete data were available for all 288 displaced persons (114 from the shelter group; 174 from the community group). Seroconversion of Entamoeba histolytica was observed in 128 (44.4%) participants, with a significantly higher rate in the shelter group than in the community group (56.1% vs 36.8%; p=0.001). There were 10 cases of rubella seroconversion. After adjusting for medical history, hypertension and hyperlipidaemia, shelter stay was associated with higher risk for seroconversion (OR=2.055, 95% CI 1.251 to 3.374; p=0.004). Amoebiasis was more evident in the shelter group, although the manifestations were mild. Our results suggested that (1) a clean water supply is essential postdisaster, especially in crowded shelters, and (2) vaccination programmes should be extended to populations at higher risk for post

  4. Paid and unpaid working hours among Swedish men and women in relation to depressive symptom trajectories: results from four waves of the Swedish Longitudinal Occupational Survey of Health.

    Science.gov (United States)

    Peristera, Paraskevi; Westerlund, Hugo; Magnusson Hanson, Linda L

    2018-06-07

    Long working hours and unpaid work are possible risk factors for depressive symptoms. However, little is known about how working hours influence the course of depressive symptoms. This study examined the influence of paid, unpaid working hours and total working hours on depressive symptoms trajectories. The study was based on data from four waves of the Swedish Longitudinal Occupational Survey of Health (SLOSH 2008-2014). We applied group-based trajectory modelling in order to identify trajectories of depressive symptoms and studied paid and unpaid working hours and total working hours as risk factors. Six trajectory groups were identified with symptoms: 'very low stable', 'low stable', 'doubtful increasing', 'high decreasing', 'mild decreasing' and 'high stable'. More time spent on unpaid work was associated with the 'low stable' (OR 1.16, 95% CI 1.04 to 1.30) and the 'high stable (OR 1.40, 95% CI 1.18 to 1.65) symptom trajectories compared with being in the 'very low stable' symptom group. In addition, more total working hours was associated with a higher probability of having 'high decreasing' (OR 1.30, 95% CI 1.14 to 1.48) and 'high stable' (OR 1.22, 95% CI 1.01 to 1.47) symptoms, when adjusting for sex, age, civil status and socioeconomic status. The results, however, differed somewhat for men and women. More unpaid working hours was more clearly associated with higher symptom trajectories among women. More total working hours was associated with 'high stable' symptoms among women only. This study supported heterogeneous individual patterns of depressive symptoms over time among the Swedish working population. The results also indicate that a higher burden of unpaid work and longer total working hours, which indicate a double burden from paid and unpaid work, may be associated with higher depressive symptom trajectories, especially among women. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights

  5. The Transition to Full-Time Work of Young People Who Do Not Go to University. Longitudinal Surveys of Australian Youth. Research Report 49

    Science.gov (United States)

    Marks, Gary N.

    2006-01-01

    This report focuses on the transition to full-time employment of young people who do not go to university. The majority of Australia's school leavers do not enroll in university, and it is important to better understand the pathways that they follow. The report uses a substantial longitudinal dataset to map the dynamics of the youth labour market,…

  6. Internato Longitudinal

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    Marcelo Marcos Piva Demarzo

    Full Text Available O internato médico tem gerado recorrente debate frente às transformações curriculares em andamento no País. A despeito das discussões, um modelo de internato consonante com essas mudanças ainda não foi consistentemente delineado. Neste ensaio, trazemos uma proposta de matriz estruturante para o internato médico. Propomos que o internato médico seja realizado durante os seis anos do curso, de forma longitudinal, tendo como eixo estruturante a clínica da Atenção Básica (AB. Esse modelo de "internato longitudinal" prevê a introdução progressiva na prática clínica, iniciando-se pela AB nos dois primeiros anos, acrescentando-se progressivamente os ambulatórios de especialidades, os estágios hospitalares e demais atividades práticas, alcançando-se, dessa forma, o rol de diversidade e complexidade previsto para o egresso da escola médica.

  7. How does social capital matter to the health status of older adults? Evidence from the China Health and Retirement Longitudinal Survey.

    Science.gov (United States)

    Liu, Gordon G; Xue, Xindong; Yu, Chenxi; Wang, Yafeng

    2016-09-01

    This paper uses longitudinal data from China to examine the causal relationship between structural social capital and health among Chinese older adults. We employ various econometric strategies to control for the potential endogeneity of social capital and account for the possible contextual confounding effects by including community-level social capital. We use three indicators to measure individuals' general, physical, and mental health. Results indicate that social capital has a significant and positive effect on general and physical health. Based on our primary IV findings, a one standard-deviation increase in social capital leads to a 4.9 standard-deviation decrease in the probability of having bad health and a 2.2 standard-deviation decrease in physical activity limitations. Our results are robust to a series of sensitivity checks. Further analysis suggests heterogeneous effects by age but not by gender or area of residence. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. A Longitudinal Examination of The Impact of Founding Owner Operator Characteristics on Nascent Venture Performance: Evidence from the Kauffman Firm Survey

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    Augustine Y. Dzathor

    2013-07-01

    Full Text Available This study attempts to revive and clarify the debate on ‘the entrepreneurial man’. We longitudinally examined the effects of seven founding-owner-operator characteristics (prior industry experience, level of formal education, age, gender, ethnicity and time committed to business operations on nascent venture performance. Our results indicate that owner work experience, level of education and hours worked in the business have significant effect on nascent venture performance, while inadequate owner reputation and luck of ethnic social capital may negatively affect nascent venture performance. Our findings also suggest that characteristic of the ‘entrepreneurial man’ are dynamic and leans towards a temporal contingency model. Different entrepreneur characteristics seem to assume prominence in firm performance at different times in a nascent venture’s life trajectory.

  9. Alumni Perspectives Survey, 2010. Survey Report

    Science.gov (United States)

    Sheikh, Sabeen

    2010-01-01

    During the months of April and September of 2009, the Graduate Management Admission Council[R] (GMAC[R]) conducted the Alumni Perspectives Survey, a longitudinal study of prior respondents to the Global Management Education Graduate Survey of management students nearing graduation. A total of 3,708 alumni responded to the April 2009 survey,…

  10. Longitudinal relationship between traumatic brain injury and the risk of incident optic neuropathy: A 10-year follow-up nationally representative Taiwan survey.

    Science.gov (United States)

    Chen, Ying-Jen; Liang, Chang-Min; Tai, Ming-Cheng; Chang, Yun-Hsiang; Lin, Tzu-Yu; Chung, Chi-Hsiang; Lin, Fu-Huang; Tsao, Chang-Huei; Chien, Wu-Chien

    2017-10-17

    Accumulating evidences had shown that traumatic brain injury was associated with visual impairment or vision loss. However, there were a limited number of empirical studies regarding the longitudinal relationship between traumatic brain injury and incident optic neuropathy. We studied a cohort from the Taiwanese National Health Insurance data comprising 553918 participants with traumatic brain injury and optic neuropathy-free in the case group and 1107836 individuals without traumatic brain injury in the control group from 1st January 2000. After the index date until the end of 2010, Cox proportional hazards analysis was used to compare the risk of incident optic neuropathy. During the follow-up period, case group was more likely to develop incident optic neuropathy (0.24%) than the control group (0.11%). Multivariate Cox regression analysis demonstrated that the case group had a 3-fold increased risk of optic neuropathy (HR = 3.017, 95% CI = 2.767-3.289, p optic neuropathy. Our study provided evidence of the increased risk of incident optic neuropathy after traumatic brain injury during a 10-year follow-up period. Patients with traumatic brain injury required periodic and thorough eye examinations for incident optic neuropathy to prevent potentially irreversible vision loss.

  11. Association of daytime napping with prediabetes and diabetes in a Chinese population: Results from the baseline survey of the China Health and Retirement Longitudinal Study.

    Science.gov (United States)

    Yin, Xin; Liu, Qi; Wei, Jiate; Meng, Xin; Jia, Chongqi

    2018-04-01

    Only a few studies have investigated the effects of daytime napping on diabetes, and these studies have reported conflicting results. The aim of the present study was to examine whether daytime napping is associated with a higher risk of prediabetes and diabetes. The present cross-sectional study of napping duration in relation to prediabetes and diabetes was conducted in 12 277 participants. Data from the first wave (2011) of the China Health and Retirement Longitudinal Study were used. Daytime napping was divided into four groups: no napping (reference) and napping for 1-30, 31-90, and >90 min. Multinomial logistic regression was used to obtain odds ratios (ORs) and 95% confidence intervals (CIs). Individuals who reported taking daily afternoon naps accounted for 53.39% of all participants. Nappers had a higher prevalence of prediabetes and diabetes than non-nappers. Compared with the reference group, the weighted fully adjusted ORs (95% CI) were 1.36 (1.10-1.68) and 1.61 (1.22-2.13) for napping >90 min in prediabetic and diabetic patients, respectively. Long daytime napping duration was positively associated with prediabetes and diabetes. Further physiological and cohort studies are needed to confirm these results and elucidate potential mechanisms. © 2017 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and John Wiley & Sons Australia, Ltd.

  12. Longitudinal survey of Staphylococcus aureus in cystic fibrosis patients using a multiple-locus variable-number of tandem-repeats analysis method

    OpenAIRE

    Vergnaud Gilles; Moissenet Didier; Corvol Harriet; Fauroux Brigitte; Corbineau Gaëlle; Hormigos Katia; Vu-Thien Hoang; Pourcel Christine

    2010-01-01

    Abstract Background Staphylococcus aureus infection in patients with cystic fibrosis (CF) is frequent and may be due to colonization by a few pathogenic lineages. Systematic genotyping of all isolates, methicillin-susceptible S. aureus (MSSA) as well as methicillin-resistant S. aureus (MRSA) is necessary to identify such lineages and follow their evolution in patients. Multiple-locus variable-number tandem repeat analysis (MLVA/VNTR) was used to survey S. aureus clinical isolates in a French ...

  13. Eight-year incidence of psychiatric disorders and service use from adolescence to early adulthood: longitudinal follow-up of the Mexican Adolescent Mental Health Survey.

    Science.gov (United States)

    Benjet, Corina; Borges, Guilherme; Méndez, Enrique; Albor, Yesica; Casanova, Leticia; Orozco, Ricardo; Curiel, Teresa; Fleiz, Clara; Medina-Mora, María Elena

    2016-02-01

    Half of mental disorders have their first onset before adulthood when the presence of a disorder may be particularly disruptive to developmental milestones. Retrospective prevalence estimates have been shown to underestimate the burden of mental illness and scarce data are available on the incidence of disorders throughout the adolescent period, especially in developing countries. Thus, the objective was to determine the incidence of mental disorders in an 8-year period from adolescence to young adulthood, onset of service use and their predictors in a Mexican cohort. 1071 respondents from a representative two-wave panel sample participated in the Mexican Adolescent Mental Health Survey in 2005 and in the follow-up survey in 2013. Disorders were evaluated with the World Mental Health Composite International Diagnostic Interview. 37.9% experienced the onset of a psychiatric disorder and 28.4% sought services for the first time. Substance use disorders had the greatest incidence, followed by mood and behavior disorders, anxiety disorders and lastly eating disorders. Sex, age, school dropout, childhood adversities and prior mental disorders predicted the onset of new disorders. Being female, having more educated parents and most classes of disorder predicted first time service use. These findings contribute to a paradigm shift in conceptions of mental disorder similar to how we think of common physical afflictions as near universal experiences across the life course, but less frequent at any given moment. Adolescents are particularly vulnerable. Therefore, public health policy should focus on early universal promotion of positive mental health and structural determinants of mental health.

  14. NEFSC 2002 Surfclam and Ocean Quahog Survey (DE0206, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The 2002 region-wide survey for Atlantic surfclam (Spisula solidissima) and Ocean Quahog (Arctica islandica) was conducted in continental shelf waters, from Delmarva...

  15. The effect of Avoidant Personality Disorder on the persistence of Generalized Social Anxiety Disorder in the general population: results from a longitudinal, nationally representative mental health survey.

    Science.gov (United States)

    Cox, Brian J; Turnbull, Danielle L; Robinson, Jennifer A; Grant, Bridget F; Stein, Murray B

    2011-03-01

    The primary objective of this study was to prospectively examine the role of Avoidant Personality Disorder (AvPD) as a determinant in the outcome of Generalized Social Anxiety Disorder (GSAD) using Wave 2 of the National Epidemiologic Survey of Alcohol and Related Conditions 3 years later. This study analyzed data from Waves 1 and 2 of the NESARC (n = 34,653). GSAD was operationalized based on the DSM-IV definitions of this SAD subtype. Logistic regression analyses indicated that AvPD significantly predicted the persistence of GSAD, even after adjusting for a number of important sociodemographic variables and other psychiatric comorbidity. AvPD did not significantly predict outcome in non-generalized SAD. AvPD can influence the course of GSAD in adulthood. Specific personality dimensions may underlie and explain the similarities between AvPD and GSAD. Self-criticism could be a shared feature of both AvPD and GSAD and could represent an important psychological marker of poor prognosis in comorbid GSAD and AvPD. © 2011 Wiley-Liss, Inc.

  16. Does the Regulatory Environment for E-Cigarettes Influence the Effectiveness of E-Cigarettes for Smoking Cessation?: Longitudinal Findings From the ITC Four Country Survey.

    Science.gov (United States)

    Yong, Hua-Hie; Hitchman, Sara C; Cummings, K Michael; Borland, Ron; Gravely, Shannon M L; McNeill, Ann; Fong, Geoffrey T

    2017-11-01

    To date, no studies have explored how different regulatory environments may influence the effectiveness of electronic cigarettes (ECs) as a smoking cessation aid. This study compares the real-world effectiveness of adult smokers using ECs for quitting compared with quitting unassisted or quitting with nicotine replacement therapy (NRT) and/or prescription medications in two countries with restrictive policies towards ECs (ie, Canada and Australia) versus two countries with less restrictive policies (ie, United States and United Kingdom). Data were drawn from the International Tobacco Control Four Country surveys, from the United States and Canada (2 waves, n = 318 and 380, respectively), the United Kingdom (3 waves, n = 439) and Australia (4 waves, n = 662), collected 2010-2014. Smokers at baseline wave who reported making a quit attempt at follow-up were included. The primary outcome was self-reported abstinence for at least 30 days regardless of smoking status at follow-up assessment. Data across waves were combined and analyzed using generalized estimating equations. Compared to unassisted quitting (ie, no medications or ECs), smokers who used ECs for quitting from countries with less restrictive EC policy environments were more likely (OR = 1.95, 95%CI = 1.19-3.20, p cessation are likely highly dependent on the regulatory environment. What this study adds: This is the first study to examine the impact of regulatory environment for ECs on their real-world effectiveness for smoking cessation. This study shows that in a less restrictive EC regulatory environment, use of ECs during a quit attempt facilitates, but in a more restrictive environment, it inhibits, short-term sustained abstinence. The findings underscore the need for careful consideration on how best to regulate this emerging product so that EC benefits for smoking cessation are maximized and its risks to public health are minimized. © The Author 2017. Published by Oxford University Press on behalf of

  17. When does poor subjective financial position hurt the elderly? Testing the interaction with educational attainment using a national representative longitudinal survey.

    Science.gov (United States)

    Pu, Christy; Huang, Nicole; Tang, Gao-Jun; Chou, Yiing-Jenq

    2011-03-17

    Several studies have demonstrated that perceived financial status has a significant impact on health status among the elderly. However, little is known about whether such a subjective perception interacts with objective socioeconomic status (SES) measures such as education that affect the individual's health. This research used data from the Survey of Health and Living Status of the Middle Age and Elderly in Taiwan (SHLS) conducted by the Bureau of Health Promotion, Department of Health in Taiwan. Waves 1996, 1999 and 2003 were used. The sample consisted of 2,387 elderly persons. The interactive effects of self-rated satisfaction with financial position and educational attainment were estimated. Self-rated health (SRH), depressive symptom (measured by CES-D) and mortality were used to measure health outcomes. Significant interaction effect was found for depressive symptoms. Among those who were dissatisfied with their financial position, those who were illiterate had an odds ratio (OR) of 8.3 (95% CI 4.9 to 14.0) for having depressive symptoms compared with those who were very satisfied with their financial position. The corresponding OR for those with college or above was only 2.7 (95% CI 1.0 to 7.3). No significant interaction effect was found for SRH and mortality. Although poor financial satisfaction was found to be related to poorer health, the strongest association for this effect was observed among those with low educational attainment, and this is especially true for depressive symptoms. Subjective financial status among the elderly should be explored in conjunction with traditional measures of SES.

  18. Longitudinal survey of two serotine bat (Eptesicus serotinus maternity colonies exposed to EBLV-1 (European Bat Lyssavirus type 1: Assessment of survival and serological status variations using capture-recapture models.

    Directory of Open Access Journals (Sweden)

    Emmanuelle Robardet

    2017-11-01

    Full Text Available This study describes two longitudinal serological surveys of European Bat Lyssavirus type 1 (EBLV-1 antibodies in serotine bat (Eptesicus serotinus maternity colonies located in the North-East of France. This species is currently considered as the main EBLV-1 reservoir. Multievent capture-recapture models were used to determine the factors influencing bat rabies transmission as this method accounts for imperfect detection and uncertainty in disease states. Considering the period of study, analyses revealed that survival and recapture probabilities were not affected by the serological status of individuals, confirming the capacity of bats to be exposed to lyssaviruses without dying. Five bats have been found with EBLV-1 RNA in the saliva at the start of the study, suggesting they were caught during virus excretion period. Among these bats, one was interestingly recaptured one year later and harbored a seropositive status. Along the survey, some others bats have been observed to both seroconvert (i.e. move from a negative to a positive serological status and serorevert (i.e. move from a positive to a negative serological status. Peak of seroprevalence reached 34% and 70% in site A and B respectively. On one of the 2 sites, global decrease of seroprevalence was observed all along the study period nuanced by oscillation intervals of approximately 2-3 years supporting the oscillation infection dynamics hypothesized during a previous EBLV-1 study in a Myotis myotis colony. Seroprevalence were affected by significantly higher seroprevalence in summer than in spring. The maximum time observed between successive positive serological statuses of a bat demonstrated the potential persistence of neutralizing antibodies for at least 4 years. At last, EBLV-1 serological status transitions have been shown driven by age category with higher seroreversion frequencies in adults than in juvenile. Juveniles and female adults seemed indeed acting as distinct drivers

  19. Longitudinal survey of two serotine bat (Eptesicus serotinus) maternity colonies exposed to EBLV-1 (European Bat Lyssavirus type 1): Assessment of survival and serological status variations using capture-recapture models.

    Science.gov (United States)

    Robardet, Emmanuelle; Borel, Christophe; Moinet, Marie; Jouan, Dorothée; Wasniewski, Marine; Barrat, Jacques; Boué, Franck; Montchâtre-Leroy, Elodie; Servat, Alexandre; Gimenez, Olivier; Cliquet, Florence; Picard-Meyer, Evelyne

    2017-11-01

    This study describes two longitudinal serological surveys of European Bat Lyssavirus type 1 (EBLV-1) antibodies in serotine bat (Eptesicus serotinus) maternity colonies located in the North-East of France. This species is currently considered as the main EBLV-1 reservoir. Multievent capture-recapture models were used to determine the factors influencing bat rabies transmission as this method accounts for imperfect detection and uncertainty in disease states. Considering the period of study, analyses revealed that survival and recapture probabilities were not affected by the serological status of individuals, confirming the capacity of bats to be exposed to lyssaviruses without dying. Five bats have been found with EBLV-1 RNA in the saliva at the start of the study, suggesting they were caught during virus excretion period. Among these bats, one was interestingly recaptured one year later and harbored a seropositive status. Along the survey, some others bats have been observed to both seroconvert (i.e. move from a negative to a positive serological status) and serorevert (i.e. move from a positive to a negative serological status). Peak of seroprevalence reached 34% and 70% in site A and B respectively. On one of the 2 sites, global decrease of seroprevalence was observed all along the study period nuanced by oscillation intervals of approximately 2-3 years supporting the oscillation infection dynamics hypothesized during a previous EBLV-1 study in a Myotis myotis colony. Seroprevalence were affected by significantly higher seroprevalence in summer than in spring. The maximum time observed between successive positive serological statuses of a bat demonstrated the potential persistence of neutralizing antibodies for at least 4 years. At last, EBLV-1 serological status transitions have been shown driven by age category with higher seroreversion frequencies in adults than in juvenile. Juveniles and female adults seemed indeed acting as distinct drivers of the rabies

  20. Applied longitudinal analysis

    CERN Document Server

    Fitzmaurice, Garrett M; Ware, James H

    2012-01-01

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

  1. Associations of sleep duration and prediabetes prevalence in a middle-aged and elderly Chinese population with regard to age and hypertension: The China Health and Retirement Longitudinal Study baseline survey.

    Science.gov (United States)

    Yan, Mingming; Fu, Zhen; Qin, Tingting; Wu, Nanjin; Lv, Yalan; Wei, Qinyun; Jiang, Hongwei; Yin, Ping

    2018-03-24

    The aim of the present study was to examine the age-specific associations between self-reported sleep duration and prevalent prediabetes in middle-aged and elderly Chinese with or without hypertension. In all, 2985 Chinese adults aged ≥45 years from the China Health and Retirement Longitudinal Study (CHARLS) baseline survey were selected for analysis. Sleep duration was assessed by structured questionnaires and then categorized into three groups (≤6, 6-8, and >8 h). The prevalence of prediabetes was defined using fasting plasma glucose (100-125 mg/dL) and/or HbA1c (5.7%-6.4%) in conjunction with no previous diabetes diagnosis and no antidiabetic medication. Relationships between self-reported sleep duration and prevalent prediabetes were examined according to age (45-60 years, middle-aged; ≥60 years, elderly) and hypertension groups using Poisson regression models to estimate prevalence ratios (PRs) and 95% confidence intervals (CI). Compared with the reference group of 6-8 h sleep/night, short sleep (≤6 h/night) was associated with an increased risk of prediabetes in the whole sample (PR 1.09, 95% CI 1.01-1.17) after adjusting for confounders. This association was more pronounced in elderly participants without hypertension (PR 1.27, 95% CI 1.07-1.51). This study suggests that participants with a short sleep period are at a moderately increased risk of prediabetes, particularly in elderly subjects without hypertension. Aging and hypertension may be important in the relationship between short sleep and impaired glucose metabolism. © 2018 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and John Wiley & Sons Australia, Ltd.

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

    Science.gov (United States)

    Seo, Dong-Chul; Li, Kaigang

    2012-01-01

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

  3. Restoration of longitudinal images.

    Science.gov (United States)

    Hu, Y; Frieden, B R

    1988-01-15

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

  4. Application of multidimensional IRT models to longitudinal data

    NARCIS (Netherlands)

    te Marvelde, J.M.; Glas, Cornelis A.W.; Van Landeghem, Georges; Van Damme, Jan

    2006-01-01

    The application of multidimensional item response theory (IRT) models to longitudinal educational surveys where students are repeatedly measured is discussed and exemplified. A marginal maximum likelihood (MML) method to estimate the parameters of a multidimensional generalized partial credit model

  5. On Longitudinal Spectral Coherence

    DEFF Research Database (Denmark)

    Kristensen, Leif

    1979-01-01

    It is demonstrated that the longitudinal spectral coherence differs significantly from the transversal spectral coherence in its dependence on displacement and frequency. An expression for the longitudinal coherence is derived and it is shown how the scale of turbulence, the displacement between ...... observation sites and the turbulence intensity influence the results. The limitations of the theory are discussed....

  6. Longitudinal categorical data analysis

    CERN Document Server

    Sutradhar, Brajendra C

    2014-01-01

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

  7. Longitudinal beam dynamics

    International Nuclear Information System (INIS)

    Tecker, F

    2014-01-01

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

  8. LIA longitudinal coupling impedance

    International Nuclear Information System (INIS)

    Faltens, A.

    1980-01-01

    The beam generated fields enter into the problems of waveform generation and longitudinal stability. In the former, provision must be made for the longitudinally defocusing forces due to the space charge and the beam loading effects on the accelerating voltage due to the current of a presumably known bunch. In the latter, the concern is for the growth of unintentional perturbations to unacceptably large values through the interaction of the charge and current fluctuations with the rest of the beam and the surrounding structures. These beam generated electric fields may be related to the beam current through a coupling impedance

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

    Science.gov (United States)

    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…

  10. Longitudinal Analysis of Academic Burnout in Korean Middle School Students.

    Science.gov (United States)

    Kim, Boyoung; Lee, Minyoung; Kim, Keunhwa; Choi, Hyunju; Lee, Sang Min

    2015-10-01

    The purpose of the study was to investigate the longitudinal relationships between the initial values and slopes of three dimensions of burnout syndrome (i.e. emotional exhaustion, cynicism and academic inefficacy). The study utilized four-wave longitudinal data from a total of 367 (81.6% response rate) middle school students in South Korea. Comprising a 6-month interval survey, the first survey was conducted in June 2010, the second in December 2010, the third in June 2011 and the fourth in December 2011. All participants were 13-year-olds at the first and second surveys, and 14-year-olds at the third and fourth surveys. The Maslach Burnout Inventory-Student Survey was used for each survey to assess the level of academic burnout. The longitudinal data were analysed using latent growth modelling. The results of the study indicated that high initial values (intercept) for emotional exhaustion were associated with a higher rate of increase (slope) in cynicism and academic inefficacy. On the other hand, high initial values for cynicism and academic inefficacy were associated with a lower rate of increase in the other dimensions. This longitudinal study should promote understanding of burned-out students and contribute to the literature by informing the design of prevention programmes for academic burnout. Copyright © 2014 John Wiley & Sons, Ltd.

  11. Longitudinal joint specifications and performance.

    Science.gov (United States)

    2012-08-01

    Deterioration of longitudinal joints is widely recognized as one of the major factors contributing to failure of asphalt pavements. Finding : ways to improve the durability of longitudinal joints will lead to improved service lives and lower life cyc...

  12. The Millennium Cohort Study: Answering Long-Term Health Concerns of US Military Service Members by Integrating Longitudinal Survey Data with Military Health System Records. Part 2. Pre-Deployment

    Science.gov (United States)

    2013-01-01

    8217, Psychological Medicine, vol. 38, no. 4, pp. 511-522. Jacobson IG, Ryan MAK, Hooper TI, Smith TC, Amoroso PJ, Boyko EJ, Gackstetter GD, Wells TS...Instruments Embedded within the Survey Construct Inventory Physical, mental, and functional health Short-Form 36 Psychological assessment...including symptoms of Patient Health Questionnaire depression, anxiety, panic syndrome, binge-eating, bulimia (PHQ) nervosa, and alcohol abuse Post

  13. Surveying Future Surveys

    Science.gov (United States)

    Carlstrom, John E.

    2016-06-01

    The now standard model of cosmology has been tested and refined by the analysis of increasingly sensitive, large astronomical surveys, especially with statistically significant millimeter-wave surveys of the cosmic microwave background and optical surveys of the distribution of galaxies. This talk will offer a glimpse of the future, which promises an acceleration of this trend with cosmological information coming from new surveys across the electromagnetic spectrum as well as particles and even gravitational waves.

  14. Transverse and Longitudinal proximity effect

    Science.gov (United States)

    Jalan, Pryianka; Chand, Hum; Srianand, Raghunathan

    2018-04-01

    With close pairs (˜1.5arcmin) of quasars (QSOs), absorption in the spectra of a background quasar in the vicinity of a foreground quasar can be used to study the environment of the latter quasar at kpc-Mpc scales. For this we used a sample of 205 quasar pairs from the Sloan Digital Sky-Survey Data Release 12 (SDSS DR12) in the redshift range of 2.5 to 3.5 by studying their H I Ly-α absorption. We study the environment of QSOs both in the longitudinal as well as in the transverse direction by carrying out a statistical comparison of the Ly-α absorption lines in the quasar vicinity to that of the absorption lines caused by the inter-galactic medium (IGM). This comparison was done with IGM, matched in absorption redshift and signal-to-noise ratio (SNR) to that of the proximity region. In contrast to the measurements along the line-of-sight, the regions transverse to the quasars exhibit enhanced H I Ly-α absorption. This discrepancy can either be interpreted as due to an anisotropic emission from the quasars or as a consequence of their finite lifetime.

  15. A Pluralistic, Longitudinal Method

    DEFF Research Database (Denmark)

    Evers, Winie; Marroun, Sana; Young, Louise

    2017-01-01

    There is recognition in business markets of the need for connected relationships to enable the survival and growth of firms. Finding new ways to collaborate enables firms to better seek opportunities and challenges and enhance network capability. However the traditional methods used to research...... and analysis. Longitudinal research considers a Danish advertising and communication firm looking for new ideas by involving their network in order to help them to compete in their environment of rapid globalization and emergence of new technologies. A five stage research design considered how network...

  16. A longitudinal study

    OpenAIRE

    Kristen, Astrid

    2010-01-01

    Does playing violent video games increase aggressive behavior over time or is it aggressive children who increasingly seek out (and play) these violent video games? To study such long-term effects a longitudinal design is necessary. Within a field study in a large German city (Kinder, Computer, Hobby, Lernen – KUHL, Freie Universtität Berlin) about 115 elementary school boys attending in the beginning (t1) classrooms of the third and fourth grade and twelve months later (t2) classrooms of the...

  17. A Longitudinal Study Assessing the Microsoft Office Skills Course

    Science.gov (United States)

    Carpenter, Donald A.; McGinnis, Denise; Slauson, Gayla Jo; Snyder, Johnny

    2013-01-01

    This paper explains a four-year longitudinal study of the assessment process for a Microsoft Office skills course. It examines whether there is an increase in students' knowledge based on responses to pre- and post-surveys that asked students to evaluate how well they can do particular tasks. Classical classroom teaching methods were used in the…

  18. Thought Suppression and Meaning in Life: A Longitudinal Investigation

    Science.gov (United States)

    Krause, Neal

    2007-01-01

    The purpose of this study is to see if older adults who experience problems with thought suppression tend to encounter greater difficulty deriving a sense of meaning in life. Data from a longitudinal nationwide survey of older people (N = 988) indicate that greater difficulty with thought suppression is associated with a decline in meaning over…

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

    Science.gov (United States)

    Russo, Silvia; Roccato, Michele; Vieno, Alessio

    2013-01-01

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

  20. Keeping secrets from parents: Longitudinal associations of secrecy in adolescence

    NARCIS (Netherlands)

    Frijns, T.; Finkenauer, C.; Vermulst, A.A.; Engels, R.C.M.E.

    2005-01-01

    A 2-wave survey study among 1173 10-14-year-olds tested the longitudinal contribution of secrecy from parents to psychosocial and behavioral problems in adolescence. Additionally, it investigated a hypothesized contribution of secrecy from parents to adolescent development by examining its relation

  1. Potential Reciprocal Relationship between Motivation and Achievement: A Longitudinal Study

    Science.gov (United States)

    Liu, Yuan; Hou, Shumeng

    2018-01-01

    Among the non-cognitive factors that influence academic achievement, intrinsic motivation has been found to be a potential reciprocal factor. The present study aims to determine the causal relationship between other types of motivation and academic achievement. For this purpose, a large-scale data survey, the National Education Longitudinal Study…

  2. Predictors of Adolescent Breakfast Consumption: Longitudinal Findings from Project EAT

    Science.gov (United States)

    Bruening, Meg; Larson, Nicole; Story, Mary; Neumark-Sztainer, Dianne; Hannan, Peter

    2011-01-01

    Objective: To identify predictors of breakfast consumption among adolescents. Methods: Five-year longitudinal study Project EAT (Eating Among Teens). Baseline surveys were completed in Minneapolis-St. Paul schools and by mail at follow-up by youth (n = 800) transitioning from middle to high school. Linear regression models examined associations…

  3. Bunched beam longitudinal stability

    International Nuclear Information System (INIS)

    Baartman, R.

    1991-05-01

    Instabilities driven by narrow-band impedances can be stabilized by Landau damping arising from the synchrotron frequency spread due to the nonlinearity of the rf wave-form. We calculate stability diagrams for various phase space distributions. We find that distributions without tails are unstable in the 'negative mass' regime (inductive impedance below transition or capacitive impedance above transition). We also find that longitudinal instability thresholds of the (usually neglected) higher order radial modes are lower than expected. For example, the next to lowest dipole mode has a lower threshold than the lowest sextupole mode even though the latter has the larger growth rate in the absence of Landau damping. (Author) 5 refs., 5 figs

  4. LEIR longitudinal studies

    CERN Document Server

    Albright, S; Hancock, S

    2017-01-01

    Towards the end of 2015 and during 2016 there were exten-sive studies of longitudinal beam dynamics in LEIR aimedat improving extracted intensities. As the driving source oflosses early in the ramp was shown to be transverse spacecharge tune spread a significant improvement came fromflattening the beam profile to increase the bunching factorby offsetting the RF frequency from the beam revolution fre-quency. Further benefits were provided by modulating theRF frequency during capture, leading to emittance blow-upand improved reproducibility. The use of two RF cavitiesduring operation was studied to try and further increase thecaptured emittance, however after careful alignment of theRF it was found that a hard limit in the bunch heigh of approx-imately 7 MeV exists. Due to the acceptance limit there wasno operational benefit to using both cavities simultaneously

  5. Fundamentals - longitudinal motion

    International Nuclear Information System (INIS)

    Weng, W.T.

    1989-01-01

    There are many ways to accelerate charged particles to high energy for physics research. Each has served its purpose but eventually has encountered fundamental limitations of one kind or another. Looking at the famous Livingston curve, the initial birth and final level-off of all types of accelerators is seen. In fact, in the mid-80s we personally witnessed the creation of a new type of collider - the Stanford Linear Collider. Also witnessed, was the resurgence of study into novel methods of acceleration. This paper will cover acceleration and longitudinal motion in a synchrotron. A synchrotron is a circular accelerator with the following three characteristics: (1) Magnetic guiding (dipole) and confinement (quadrupole) components are placed in a small neighborhood around the equilibrium orbit. (2) Particles are kept in resonance with the radio-frequency electric field indefinitely to achieve acceleration to higher energies. (3) Magnetic fields are varied adiabatically with the energy of the particle. D. Edwards described the transverse oscillations of particles in a synchrotron. Here the author talks about the longitudinal oscillations of particles. The phase stability principle was invented by V. Veksler and E. McMillan independently in 1945. The phase stability and strong focusing principle, invented by Courant and Livingston in 1952, enabled the steady energy gain of accelerators and storage rings witnessed during the past 30 years. This paper is a unified overview of the related rf subjects in an accelerator and a close coupling between accelerator physics and engineering practices, which is essential for the major progress in areas such as high intensity synchrotrons, a multistage accelerator complex, and anti-proton production and cooling, made possible in the past 20 years

  6. Loading Conditions and Longitudinal Strength

    DEFF Research Database (Denmark)

    Sørensen, Herman

    1995-01-01

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

  7. Longitudinal Research with Latent Variables

    CERN Document Server

    van Montfort, Kees; Satorra, Albert

    2010-01-01

    This book combines longitudinal research and latent variable research, i.e. it explains how longitudinal studies with objectives formulated in terms of latent variables should be carried out, with an emphasis on detailing how the methods are applied. Because longitudinal research with latent variables currently utilizes different approaches with different histories, different types of research questions, and different computer programs to perform the analysis, the book is divided into nine chapters. Starting from some background information about the specific approach, short history and the ma

  8. Longitudinal emission tomography of thyroid and heart

    International Nuclear Information System (INIS)

    Giessen, J.W. van.

    1986-01-01

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

  9. Summary of longitudinal instabilities workshop

    Energy Technology Data Exchange (ETDEWEB)

    Chasman, R.

    1976-01-01

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

  10. Longitudinal dynamics in storage rings

    International Nuclear Information System (INIS)

    Colton, E.P.

    1986-01-01

    The single-particle equations of motion are derived for charged particles in a storage ring. Longitudinal space charge is included in the potential assuming an infinitely conducting circular beam pipe with a distributed inductance. The framework uses Hamilton's equations with the canonical variables phi and W. The Twiss parameters for longitudinal motion are also defined for the small amplitude synchrotron oscillations. The space-charge Hamiltonian is calculated for both parabolic bunches and ''matched'' bunches. A brief analysis including second-harmonic rf contributions is also given. The final sections supply calculations of dynamical quantities and particle simulations with the space-charge effects neglected

  11. Longitudinal single-bunch instabilities

    International Nuclear Information System (INIS)

    Migliorati, M.; Palumbo, L.; Rome Univ. La Sapienza, Rome

    2001-02-01

    After introducing the concepts of longitudinal wakefield and coupling impedance, it is reviewed the theory of longitudinal single-bunch collective effects in storage rings. From the Fokker-Planck equation it is first derived the stationary solution describing the natural single-bunch regime, and then treat the problem of microwave instability, showing the different approaches used for estimating the threshold current. The lecture is ended with the semi-empirical laws that allow everyone to obtain the single-bunch behaviour above threshold, and with a description of the simulation codes that are now reliable tools for investigating all these effects

  12. Passive longitudinal phase space linearizer

    Directory of Open Access Journals (Sweden)

    P. Craievich

    2010-03-01

    Full Text Available We report on the possibility to passively linearize the bunch compression process in electron linacs for the next generation x-ray free electron lasers. This can be done by using the monopole wakefields in a dielectric-lined waveguide. The optimum longitudinal voltage loss over the length of the bunch is calculated in order to compensate both the second-order rf time curvature and the second-order momentum compaction terms. Thus, the longitudinal phase space after the compression process is linearized up to a fourth-order term introduced by the convolution between the bunch and the monopole wake function.

  13. Longitudinal feedback system for PEP

    International Nuclear Information System (INIS)

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

    1979-02-01

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

  14. Longitudinal bulk acoustic mass sensor

    DEFF Research Database (Denmark)

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

    2009-01-01

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

  15. Correspondence analysis of longitudinal data

    NARCIS (Netherlands)

    Van der Heijden, P.G.M.|info:eu-repo/dai/nl/073087998

    2005-01-01

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

  16. Longitudinal heritability of childhood aggression

    NARCIS (Netherlands)

    Porsch, R.M.P.; Middeldorp, C.M.; Cherny, S.S.; Krapohl, E.; van Beijsterveldt, C.E.M.; Loukola, A.; Korhonen, T.; Pulkkinen, L.; Corley, R.P.; Rhee, S.; Kaprio, J.; Rose, R.; Hewitt, J.K.; Sham, P.; Plomin, R.; Boomsma, D.I.; Bartels, M.

    2016-01-01

    The genetic and environmental contributions to the variation and longitudinal stability in childhood aggressive behavior were assessed in two large twin cohorts, the Netherlands Twin Register (NTR), and the Twins Early Development Study (TEDS; United Kingdom). In NTR, maternal ratings on aggression

  17. Developing a longitudinal cancer nursing education program in Honduras.

    Science.gov (United States)

    Sheldon, Lisa Kennedy; Wise, Barbara; Carlson, Julie R; Dowds, Cynthia; Sarchet, Vanessa; Sanchez, Jose Angel

    2013-12-01

    The present paper is a longitudinal study which aims to develop and deliver cancer nursing education conferences in Honduras using volunteer nurse educators. This program intends to (1) perform site assessments of work environments and resources for cancer care in Honduras, (2) develop cancer nursing education programs, (3) survey conference participants continuing education needs, (4) deliver cancer nursing education conferences, and (5) share data with local and global partners for future cancer programs. The study draws on a longitudinal program development with site assessments, data collection, and educational conferences at two time points. Assessments and surveys were used for conference development and delivery by volunteer nurse educators. Site assessments and conferences were delivered twice. Data were collected regarding assessments and surveys to inform program development. Survey data revealed that 65 % had internet access. Participants desired more information about handling of chemotherapy, symptom management, and palliative care. Volunteer nurse educators perform site assessments and develop educational programming for cancer nurses. Local and global partners should explore internet-based programs between site visits to create sustainable education programs.

  18. A typology of longitudinal integrated clerkships.

    Science.gov (United States)

    Worley, Paul; Couper, Ian; Strasser, Roger; Graves, Lisa; Cummings, Beth-Ann; Woodman, Richard; Stagg, Pamela; Hirsh, David

    2016-09-01

    Longitudinal integrated clerkships (LICs) represent a model of the structural redesign of clinical education that is growing in the USA, Canada, Australia and South Africa. By contrast with time-limited traditional block rotations, medical students in LICs provide comprehensive care of patients and populations in continuing learning relationships over time and across disciplines and venues. The evidence base for LICs reveals transformational professional and workforce outcomes derived from a number of small institution-specific studies. This study is the first from an international collaborative formed to study the processes and outcomes of LICs across multiple institutions in different countries. It aims to establish a baseline reference typology to inform further research in this field. Data on all LIC and LIC-like programmes known to the members of the international Consortium of Longitudinal Integrated Clerkships were collected using a survey tool developed through a Delphi process and subsequently analysed. Data were collected from 54 programmes, 44 medical schools, seven countries and over 15 000 student-years of LIC-like curricula. Wide variation in programme length, student numbers, health care settings and principal supervision was found. Three distinct typological programme clusters were identified and named according to programme length and discipline coverage: Comprehensive LICs; Blended LICs, and LIC-like Amalgamative Clerkships. Two major approaches emerged in terms of the sizes of communities and types of clinical supervision. These referred to programmes based in smaller communities with mainly family physicians or general practitioners as clinical supervisors, and those in more urban settings in which subspecialists were more prevalent. Three distinct LIC clusters are classified. These provide a foundational reference point for future studies on the processes and outcomes of LICs. The study also exemplifies a collaborative approach to medical

  19. Single bunch fast longitudinal instability

    International Nuclear Information System (INIS)

    Wang, J.M.; Pellegrini, C.

    1979-01-01

    Single bunch longitudinal instability producing an increase of the bunch area have been observed in proton synchrotron and storage rings. Signals at microwave frequencies are observed during the bunch blow-up and because of this the effect has been called the microwave instability. A similar increase in bunch area is observed also in electron storage rings, where it is usually referred to as the bunch lengthening effect. This paper is an attempt to obtain a more general theory of this effect. Here we describe the model used and the method of calculation, together with some general results. More detailed results will be given in another paper. The main result is the derivation of a condition for the existence of a fast longitudinal bunch blow-up. This condition is a generalized threshold formula, showing explicitly the dependence on the bunch energy spread and length. This condition is qualitatively in agreement with Boussard's suggestion

  20. Single bunch fast longitudinal instability

    International Nuclear Information System (INIS)

    Wang, J.M.; Pellegrini, C.

    1979-01-01

    Single bunch longitudinal instability producing an increase of the bunch areas has been observed in proton synchrotron and storage rings. Singals at microwave frequencies are observed during the bunch blow-up and because of this the effect has been called the microwave instability. A similar increase in bunch area is observed also in electron storage rings, where it is usually referred to as the bunch lengthening effect. This paper is an attempt to obtain a more general theory of this effect. Here we describe the model used and the method of calculation, together with some general results. The main result of this paper is the derivation of a condition for the existence of a fast longitudinal bunch blow-up. This condition is a generalized threshold formula, showing explicitly the dependence on the bunch energy spread and length

  1. Longitudinal Research in Social Science: Some Theoretical Challenges

    Directory of Open Access Journals (Sweden)

    Thomas K. Burch

    2001-12-01

    Full Text Available Every advance carries with it potential problems, and longitudinal analysis is no exception. This paper focuses on the problems related to the massive amounts of data generated by longitudinal surveys. It is argued that a proliferation of data may be to the good but it will not necessarily lead to better scientific knowledge. Most demographers think the logical positivist way that theory arises out of empirical generalisations, but massive empirical investigations have only led to disappointing theoretical outcomes in demography. This paper discusses one way out of this impasse - to adopt a different view of theory, a model-based view of science. Theoretical models based on empirical generalisation should become the main representational device in science.

  2. "Suntelligence" Survey

    Science.gov (United States)

    ... to the American Academy of Dermatology's "Suntelligence" sun-smart survey. Please answer the following questions to measure ... be able to view a ranking of major cities suntelligence based on residents' responses to this survey. ...

  3. Parameterized Linear Longitudinal Airship Model

    Science.gov (United States)

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

    2010-01-01

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

  4. Bayesian Nonparametric Longitudinal Data Analysis.

    Science.gov (United States)

    Quintana, Fernando A; Johnson, Wesley O; Waetjen, Elaine; Gold, Ellen

    2016-01-01

    Practical Bayesian nonparametric methods have been developed across a wide variety of contexts. Here, we develop a novel statistical model that generalizes standard mixed models for longitudinal data that include flexible mean functions as well as combined compound symmetry (CS) and autoregressive (AR) covariance structures. AR structure is often specified through the use of a Gaussian process (GP) with covariance functions that allow longitudinal data to be more correlated if they are observed closer in time than if they are observed farther apart. We allow for AR structure by considering a broader class of models that incorporates a Dirichlet Process Mixture (DPM) over the covariance parameters of the GP. We are able to take advantage of modern Bayesian statistical methods in making full predictive inferences and about characteristics of longitudinal profiles and their differences across covariate combinations. We also take advantage of the generality of our model, which provides for estimation of a variety of covariance structures. We observe that models that fail to incorporate CS or AR structure can result in very poor estimation of a covariance or correlation matrix. In our illustration using hormone data observed on women through the menopausal transition, biology dictates the use of a generalized family of sigmoid functions as a model for time trends across subpopulation categories.

  5. A study of the HEB longitudinal dynamics

    International Nuclear Information System (INIS)

    Larson, D.J.

    1993-12-01

    A study of the High Energy Booster (HEB) longitudinal dynamics is presented. Full derivations of ramp dependent longitudinal variables are given. The formulas assume that the input magnetic field and beam longitudinal emittance are known as a function of time, and that either the rf voltage or the rf bucket area are known as a function of time. Once these three inputs are specified, the formulas can be used to calculate values for all other longitudinal dynamics variables. The formulas have been incorporated into a single computer code named ELVIRA: Evaluation of Longitudinal Variables in Relativistic Accelerators. The ELVIRA code is documented here in detail. The ELVIRA code is used under two initial longitudinal emittance assumptions to plot ramp functions for the longitudinal dynamics design of the HEB as of May 5, 1992

  6. Effects of Maternal Parenting and Mother-Child Relationship Quality on Short-Term Longitudinal Change in Self-Regulation in Early Adolescence

    Science.gov (United States)

    Moilanen, Kristin L.; Rambo-Hernandez, Karen E.

    2017-01-01

    The purpose of the present study was to explore the degree to which short-term longitudinal change in adolescent self-regulation was attributable to maternal parenting and mother-child relationship quality. A total of 821 mother-adolescent dyads provided data in the 1992 and 1994 waves of the Children of the National Longitudinal Survey of…

  7. Longitudinal charge nurse leadership development and evaluation.

    Science.gov (United States)

    Krugman, Mary; Heggem, Laura; Kinney, Lisa Judd; Frueh, Margaret

    2013-09-01

    The study's aim was to examine longitudinal outcomes of a leadership program for permanent and relief charge nurse from 1996 to 2012 using action research and Kouzes and Posner's The Leadership Challenge conceptual frameworks. Charge nurses hold significant oversight of patient safety, quality, and team functioning. This study contributes knowledge regarding charge nurse leadership and organization outcomes associated with these essential roles over time. Data were collected over 6 time periods using Kouzes and Posner's The Leadership Practices Inventory (LPI) and internally developed action research tools. Surveys were aligned with leadership and work environment changes to examine outcomes. Charge nurse leadership LPI mean ratings improved. Relief charge nurses reached similar LPI outcomes by 2012, with no statistical differences in mean or domain scores. Action research methods facilitated executive decision making during change processes. Demographics shifted with younger charge nurses with less practice experience serving as charge nurses in the most recent years. Charge nurse leadership reported significant gains despite institutional changes and uneven delivery of educational interventions.

  8. A longitudinal analysis of nursing home outcomes.

    Science.gov (United States)

    Porell, F; Caro, F G; Silva, A; Monane, M

    1998-10-01

    To investigate resident and facility attributes associated with long-term care health outcomes in nursing homes. Quarterly Management Minutes Questionnaire (MMQ) survey data for Medicaid case-mix reimbursement of nursing homes in Massachusetts from 1991 to 1994, for specification of outcomes and resident attributes. Facility attributes are specified from cost report data. Multivariate logistic and "state-dependence" regression models are estimated for survival, ADL functional status, incontinence status, and mental status outcomes from longitudinal residence histories of Medicaid residents spanning 3 to 36 months in length. Outcomes are specified to be a function of resident demographic and diagnostic attributes and facility-level operating and nurse staffing attributes. The estimated parameters for resident demographic and diagnostic attributes showed a great deal of construct validity with respect to clinical expectations regarding risk factors for adverse outcomes. Few facility attributes were associated with outcomes generally, and none was significantly associated with all four outcomes. The absence of uniform associations between facility attributes and the various long-term care health outcomes studied suggests that strong facility performance on one health outcome may coexist with much weaker performance on other outcomes. This has implications for the aggregation of individual facility performance measures on multiple outcomes and the development of overall outcome performance measures.

  9. Longitudinal changes in academic motivation in Japan: Self-determination theory and East Asian cultures

    OpenAIRE

    Nishimura, Takuma; Sakurai, Shigeo

    2017-01-01

    This study examined changes in the academic motivation of Japanese junior high school students through a two-year longitudinal survey, based on self-determination theory. Japanese students (N = 410; 215 boys and 195 girls aged 12–13 years at the time of the first survey) completed the Japanese short-version of the Self-Regulation Questionnaire once each year during three consecutive grades (seventh, eighth, and ninth). The results of a latent curve model indicated that intrinsic and identifie...

  10. Psychological predictors of eco-driving: A longitudinal study

    OpenAIRE

    Lauper Elisabeth; Moser Stephanie; Fischer Maja; Matthies Ellen; Kaufmann-Hayoz Ruth

    2015-01-01

    Eco-driving has well-known positive effects on fuel economy and greenhouse-gas emissions. Moreover, eco-driving reduces road-traffic noise, which is a serious threat to the health and well-being of many people. We investigated the psychological predictors of the adoption of eco-driving from the perspective of road-traffic noise abatement. The data came from 890 car drivers who participated in a longitudinal survey over four months. Specifically, we tested the effects of the intention to preve...

  11. Longitudinal tune control in synchrotrons

    International Nuclear Information System (INIS)

    Colton, E.P.

    1984-01-01

    Dual rf systems that use fundamental and higher-harmonic cavities can be used to control the longitudinal tune in synchrotrons. The equations of motion and the Hamiltonian are defined for particle motion using dual rf systems. An example is considered using a second-harmonic system - it is shown, that as phi/sub s/ is increased, a substantial gain in bucket area over a single rf system can be realized by proper relative phasing of the first- and second-harmonic voltages

  12. A Longitudinal Study of Changes in Marketing Practices at Private Christian Colleges

    Science.gov (United States)

    Vander Schee, Brian A.

    2009-01-01

    This article presents the results of a longitudinal study investigating current marketing practices at selected church-related, private, four-year compared to those in place in 1997. The role that institutional selectivity plays in the use of marketing activities was also investigated. The researcher surveyed the admissions directors or enrollment…

  13. Are We There Yet?: A Longitudinal Look at E-Books through Students' Eyes

    Science.gov (United States)

    Hobbs, Kendall; Klare, Diane

    2016-01-01

    Starting in summer 2011, two librarians at Wesleyan University annually interviewed and directed usability studies with undergraduate students to determine how students interact with academic e-books. In 2014, the librarians used a campuswide quantitative survey to supplement these longitudinal qualitative findings. While students are increasingly…

  14. A Longitudinal Analysis of Students' Motives for Communicating with Their Instructors

    Science.gov (United States)

    Myers, Scott A.

    2017-01-01

    This study utilized the longitudinal survey research design using students' motives to communicate with their instructors as a test case. Participants were 282 undergraduate students enrolled in introductory communication courses at a large Mid-Atlantic university who completed the Student Communication Motives scale at three points (Time 1:…

  15. Linking people management and extra-role behaviour : Results of a longitudinal study

    NARCIS (Netherlands)

    Knies, Eva; Leisink, Peter

    2014-01-01

    This article examines the validity of the assumption that employees' perceptions of those people management activities of their supervisor that impact on employees' abilities, motivation and opportunities to perform influence employee extra-role behaviour. The results of a longitudinal survey with

  16. Relationships between Substance Use and Depressive Symptoms: A Longitudinal Study of Australian Adolescents

    Science.gov (United States)

    Scholes-Balog, Kirsty E.; Hemphill, Sheryl A.; Patton, George C.; Toumbourou, John W.

    2015-01-01

    This study examined longitudinal relationships between depressive symptoms and use of alcohol, cigarettes, and illicit substances among adolescents, addressing methodological limitations and potential confounding in the extant literature. The sample comprised adolescents who were surveyed in Grades 6 (n = 916), 9 (n = 804), and 11 (n = 791).…

  17. Head Start FACES: Longitudinal Findings on Program Performance. Third Progress Report.

    Science.gov (United States)

    Zill, Nicholas; Resnick, Gary; Kim, Kwang; McKey, Ruth Hubbell; Clark, Cheryl; Pai-Samant, Shefali; Connell, David; Vaden-Kiernan, Michael; O'Brien, Robert; D'Elio, Mary Ann

    The Head Start Family and Child Experiences Survey (FACES) is an ongoing, national, longitudinal study of the cognitive, social, emotional, and physical development of Head Start children; the characteristics, well-being, and accomplishments of families; the observed quality of Head Start classrooms; and the characteristics and opinions of Head…

  18. Conditions for Ubiquitous Computing: What Can Be Learned from a Longitudinal Study

    Science.gov (United States)

    Lei, Jing

    2010-01-01

    Based on survey data and interview data collected over four academic years, this longitudinal study examined how a ubiquitous computing project evolved along with the changes in teachers, students, the human infrastructure, and technology infrastructure in the school. This study also investigated what conditions were necessary for successful…

  19. 78 FR 44553 - Agency Information Collection Activities; Comment Request; Early Childhood Longitudinal Study...

    Science.gov (United States)

    2013-07-24

    ...) of the U.S. Department of Education (ED), is a survey that focuses on children's early school... child assessments. Like its sister study, the Early Childhood Longitudinal Study, Kindergarten Class of..., early learning, and school progress, drawing together information from multiple sources to provide rich...

  20. Social Capital, Self-Esteem, and Use of Online Social Network Sites: A Longitudinal Analysis

    Science.gov (United States)

    Steinfield, Charles; Ellison, Nicole B.; Lampe, Cliff

    2008-01-01

    A longitudinal analysis of panel data from users of a popular online social network site, Facebook, investigated the relationship between intensity of Facebook use, measures of psychological well-being, and bridging social capital. Two surveys conducted a year apart at a large U.S. university, complemented with in-depth interviews with 18 Facebook…

  1. A longitudinal evaluation of persons with disabilities: does a longitudinal definition help define who receives necessary care?

    Science.gov (United States)

    Chan, Leighton; Ciol, Marcia A; Shumway-Cook, Anne; Yorkston, Kathryn M; Dudgeon, Brian J; Asch, Steven M; Hoffman, Jeanne M

    2008-06-01

    To assess, using a longitudinal definition, the impact of disability on a broad range of objective health care quality indicators. Longitudinal cohort study following up with patients over several years. The first 2 interviews, 1 year apart, were used to determine each patient's disability status in activities of daily living (ADLs). Assessment of the health care indicators commenced after the second interview and continued throughout the survey period (an additional 1-3y). National survey. Participants (N=29,074) of the Medicare Current Beneficiary Survey (1992-2001) with no, increasing, decreasing, and stable ADL disability. Not applicable. The incidence of 5 avoidable outcomes, receipt of 3 preventive care measures, and adherence to 32 diagnostically based indicators assessing the quality of treatment for acute myocardial infarction [AMI], angina, breast cancer, cerebrovascular accident, transient ischemic attack, cholelithiasis, chronic obstructive pulmonary disease [COPD], congestive heart failure, depression, gastrointestinal bleeding, diabetes, and hypertension. For most indicators, less than 75% of eligible patients received necessary care, regardless of disability status. For 5 indicators, less than 50% of patients received appropriate treatment. In a logistic regression analysis that controlled for patient age, sex, race, and income, disability status was a significant factor in 7 quality measures (AMI, breast cancer, COPD, diabetes, angina, pneumonia, annual visits). Using a longitudinal definition of disability and objective health quality indicators, we found that disability status can be an important factor in determining receipt of quality health care in a broad range of diagnostic categories. However, the impact of disability status varies depending on the indicator measured. In this cohort of patients, the changing nature of a person's disability seems to have less impact than whether they ever have had any functional deficits.

  2. Exploring Longitudinal Risk-return Relationships

    DEFF Research Database (Denmark)

    Andersen, Torben J.; Bettis, Richard A.

    2015-01-01

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

  3. Survey research.

    Science.gov (United States)

    Alderman, Amy K; Salem, Barbara

    2010-10-01

    Survey research is a unique methodology that can provide insight into individuals' perspectives and experiences and can be collected on a large population-based sample. Specifically, in plastic surgery, survey research can provide patients and providers with accurate and reproducible information to assist with medical decision-making. When using survey methods in research, researchers should develop a conceptual model that explains the relationships of the independent and dependent variables. The items of the survey are of primary importance. Collected data are only useful if they accurately measure the concepts of interest. In addition, administration of the survey must follow basic principles to ensure an adequate response rate and representation of the intended target sample. In this article, the authors review some general concepts important for successful survey research and discuss the many advantages this methodology has for obtaining limitless amounts of valuable information.

  4. Longitudinal study of fingerprint recognition.

    Science.gov (United States)

    Yoon, Soweon; Jain, Anil K

    2015-07-14

    Human identification by fingerprints is based on the fundamental premise that ridge patterns from distinct fingers are different (uniqueness) and a fingerprint pattern does not change over time (persistence). Although the uniqueness of fingerprints has been investigated by developing statistical models to estimate the probability of error in comparing two random samples of fingerprints, the persistence of fingerprints has remained a general belief based on only a few case studies. In this study, fingerprint match (similarity) scores are analyzed by multilevel statistical models with covariates such as time interval between two fingerprints in comparison, subject's age, and fingerprint image quality. Longitudinal fingerprint records of 15,597 subjects are sampled from an operational fingerprint database such that each individual has at least five 10-print records over a minimum time span of 5 y. In regard to the persistence of fingerprints, the longitudinal analysis on a single (right index) finger demonstrates that (i) genuine match scores tend to significantly decrease when time interval between two fingerprints in comparison increases, whereas the change in impostor match scores is negligible; and (ii) fingerprint recognition accuracy at operational settings, nevertheless, tends to be stable as the time interval increases up to 12 y, the maximum time span in the dataset. However, the uncertainty of temporal stability of fingerprint recognition accuracy becomes substantially large if either of the two fingerprints being compared is of poor quality. The conclusions drawn from 10-finger fusion analysis coincide with the conclusions from single-finger analysis.

  5. Longitudinal Space Charge in the SPS

    CERN Document Server

    Lasheen, Alexandre

    2016-01-01

    Longitudinal instabilities due to the SPS beam coupling impedance are a major issue for future projects and it is essential to have an accurate SPS impedance model to study them. The longitudinal space charge effect can be modelled by a pure reactive impedance and should also be included in simulations as it may have an impact at low energy. In this Note, the effect of the longitudinal space charge in the SPS is evaluated by taking into account the variation of the transverse beam size and vacuum chamber geometry along the ring. Scaling laws are used to investigate what are the most important parameters for the evaluation of the longitudinal space charge impedance.

  6. The Longitudinal Association between Competitive Video Game Play and Aggression among Adolescents and Young Adults

    Science.gov (United States)

    Adachi, Paul J. C.; Willoughby, Teena

    2016-01-01

    The longitudinal association between competitive video game play and aggression among young adults and adolescents was examined. Young adults (N = 1,132; M[subscript 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[subscript…

  7. Surveys & Programs

    Science.gov (United States)

    Employment and Payroll Survey of Business Owners Work from Home Our statistics highlight trends in household statistics from multiple surveys. Data Tools & Apps Main American FactFinder Census Business Builder My residential construction. Business Dynamics Statistics (BDS) Provides measures of openings and closings, job

  8. Engineering surveying

    CERN Document Server

    Schofield, W

    2001-01-01

    The aim of Engineering Surveying has always been to impart and develop a clear understanding of the basic topics of the subject. The author has fully revised the book to make it the most up-to-date and relevant textbook available on the subject.The book also contains the latest information on trigonometric levelling, total stations and one-person measuring systems. A new chapter on satellites ensures a firm grasp of this vitally important topic.The text covers engineering surveying modules for civil engineering students on degree courses and forms a reference for the engineering surveying module in land surveying courses. It will also prove to be a valuable reference for practitioners.* Simple clear introduction to surveying for engineers* Explains key techniques and methods* Details reading systems and satellite position fixing

  9. Introduction to Longitudinal Beam Dynamics

    International Nuclear Information System (INIS)

    Holzer, B J

    2014-01-01

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

  10. Introduction to Longitudinal Beam Dynamics

    CERN Document Server

    Holzer, B J

    2014-01-01

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

  11. Introduction to Longitudinal Beam Dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Holzer, B J [European Organization for Nuclear Research, Geneva (Switzerland)

    2014-07-01

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

  12. Longitudinal association between marital disruption and child BMI and obesity.

    Science.gov (United States)

    Arkes, Jeremy

    2012-08-01

    This research examines whether family disruptions (i.e., divorces and separation) contribute to children's weight problems. The sample consists of 7,299 observations for 2,333 children, aged 5-14, over the 1986-2006 period, from a US representative sample from the Child and Young Adult Survey accompanying the National Longitudinal Survey of Youth (NLSY). The study uses individual-fixed-effects models in a longitudinal framework to compare children's BMI and weight problems before and after a disruption. Furthermore, besides doing a before-after comparison for children, the study also estimates the effects at various periods relative to the disruption in order to examine whether children are affected before the disruption and whether any effects change as time passes from the disruption, as some effects may be temporary or slow to develop. Despite having a larger sample than the previous studies, the results provide no evidence that, on average, children's BMI and BMI percentile scores (measured with continuous outcomes) are affected before the disruption, after the disruption, and as time passes from the disruption, relative to a baseline period a few years before the disruption. However, children experiencing a family disruption do have an increased risk of obesity (having a BMI percentile score of 95 or higher) in the two years leading up to the disruption as well as after the disruption, and as time passes from the disruption.

  13. Postural changes in dental hygienists. Four-year longitudinal study.

    Science.gov (United States)

    Barry, R M; Woodall, W R; Mahan, J M

    1992-01-01

    Numerous surveys identify the occurrence of musculoskeletal complaints as a concern in dentistry. However, no longitudinal data exist to indicate whether postural changes occur as a result of practicing dental hygiene. The purpose of this preliminary, four-year longitudinal study was to investigate whether any postural changes developed during the hygienists' clinical education and/or during subsequent dental hygiene practice after one and/or two years. It was anticipated that the awkward positions and intense physical demands placed on hygienists might initiate musculoskeletal problems, but that no postural changes would occur over this short period of time. Nine of 10 dental hygienists in the graduating class of 1987 were surveyed for existing musculoskeletal complaints, and the subjects were photographed for a measurement of postural change. Responses from participants indicated an increase in musculoskeletal-related complaints in each of the six areas investigated. The photographic findings indicated that one of the nine hygienists showed an increase in forward head posture, a postural change.

  14. College Women's Female Friendships: A Longitudinal View

    Science.gov (United States)

    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…

  15. What is learned from longitudinal studies of advertising and youth drinking and smoking? A critical assessment.

    Science.gov (United States)

    Nelson, Jon P

    2010-03-01

    This paper assesses the methodology employed in longitudinal studies of advertising and youth drinking and smoking behaviors. These studies often are given a causal interpretation in the psychology and public health literatures. Four issues are examined from the perspective of econometrics. First, specification and validation of empirical models. Second, empirical issues associated with measures of advertising receptivity and exposure. Third, potential endogeneity of receptivity and exposure variables. Fourth, sample selection bias in baseline and follow-up surveys. Longitudinal studies reviewed include 20 studies of youth drinking and 26 studies of youth smoking. Substantial shortcomings are found in the studies, which preclude a causal interpretation.

  16. What is Learned from Longitudinal Studies of Advertising and Youth Drinking and Smoking? A Critical Assessment

    Directory of Open Access Journals (Sweden)

    Jon P. Nelson

    2010-03-01

    Full Text Available This paper assesses the methodology employed in longitudinal studies of advertising and youth drinking and smoking behaviors. These studies often are given a causal interpretation in the psychology and public health literatures. Four issues are examined from the perspective of econometrics. First, specification and validation of empirical models. Second, empirical issues associated with measures of advertising receptivity and exposure. Third, potential endogeneity of receptivity and exposure variables. Fourth, sample selection bias in baseline and follow-up surveys. Longitudinal studies reviewed include 20 studies of youth drinking and 26 studies of youth smoking. Substantial shortcomings are found in the studies, which preclude a causal interpretation.

  17. Survey Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Cleaned and QCd data for the Fishing Effort Survey. Questions on fishing and other out are asked on weather and outdoor activity, including fishing trips. Used for...

  18. Surveying Humaness

    DEFF Research Database (Denmark)

    Markussen, Randi; Gad, Christopher

    carried out in a Danish county in order to improve treatment of people who have suffered from long-term illnesses. The surveys concern not only feed back on how people experience their present and past interaction with the social services and health care system; they also ask people to indicate the state......Christopher Gad. Ph.d. Dept. of Information and Media Studies Randi Markussen. Associate Professor, Dept. of Information and Media Studies. rmark@imv.au.dk   Abstract:   Surveying humanness -politics of care improvement   For various reasons we both were subjected to a specific survey procedure...... and development of a large collection of biological and psychological symptoms and psycho-social problems. However, the surveys say nothing about how the information will be of use to the people who answer the procedure or how this scientific intervention will be put to use more specifically within the public...

  19. Longitudinal research and data collection in primary care.

    NARCIS (Netherlands)

    Weel, C. van

    2005-01-01

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

  20. Engineering surveying

    CERN Document Server

    Schofield, W

    2007-01-01

    Engineering surveying involves determining the position of natural and man-made features on or beneath the Earth's surface and utilizing these features in the planning, design and construction of works. It is a critical part of any engineering project. Without an accurate understanding of the size, shape and nature of the site the project risks expensive and time-consuming errors or even catastrophic failure.Engineering Surveying 6th edition covers all the basic principles and practice of this complex subject and the authors bring expertise and clarity. Previous editions of this classic text have given readers a clear understanding of fundamentals such as vertical control, distance, angles and position right through to the most modern technologies, and this fully updated edition continues that tradition.This sixth edition includes:* An introduction to geodesy to facilitate greater understanding of satellite systems* A fully updated chapter on GPS, GLONASS and GALILEO for satellite positioning in surveying* Al...

  1. Does perceived discrimination affect health? Longitudinal relationships between work discrimination and women's physical and emotional health.

    Science.gov (United States)

    Pavalko, Eliza K; Mossakowski, Krysia N; Hamilton, Vanessa J

    2003-03-01

    This study uses longitudinal data to examine the causal relationships between perceived work discrimination and women's physical and emotional health. Using data on 1,778 employed women in the National Longitudinal Survey of Mature Women, we investigate the structural and individual characteristics that predict later perceptions of discrimination and the effects of those perceptions on subsequent health. We find that perceptions of discrimination are influenced by job attitudes, prior experiences of discrimination, and work contexts, but prior health is not related to later perceptions. However, perceptions of discrimination do impact subsequent health, and these effects remain significant after controlling for prior emotional health, physical health limitations, discrimination, and job characteristics. Overall, the results provide even stronger support for the health impact of workplace discrimination and suggest a need for further longitudinal analyses of causes and consequences of perceived discrimination.

  2. The Health Assessment Longitudinal File imperative: foundation for improving the health of the force.

    Science.gov (United States)

    Kemper, Judith A; Donahue, Donald A; Harris, Judith S

    2003-08-01

    A smaller active duty force and an increased operational tempo have made the Reserve components (RC) essential elements in the accomplishment of the mission of the U.S. Army. One critical factor in meeting mission is maintaining the optimal health of each soldier. Baseline health data about the RC is currently not being collected, even though increasing numbers of reserve soldiers are being activated. The Annual Health Certification and Survey is being developed as a way to meet the RCs' statutory requirement for annual certification of health while at the same time generating and tracking baseline data on each reservist in a longitudinal health file, the Health Assessment Longitudinal File. This article discusses the Annual Health Certification Questionnaire/Health Assessment Longitudinal File, which will greatly enhance the Army's ability to accurately certify the health status of the RC and track health in relation to training, mission activities, and deployment.

  3. When Does Money Make Money More Important? Survey and Experimental Evidence

    OpenAIRE

    Sanford E. DeVoe; Jeffrey Pfeffer; Byron Y. Lee

    2013-01-01

    The authors investigate how the amount and source of income affects the importance placed on money. Using a longitudinal analysis of the British Household Panel Survey and evidence from two laboratory experiments, they found that larger amounts of money received for labor were associated with individuals placing greater importance on money; but this effect did not hold for money not related to work. The longitudinal survey analysis demonstrated these differential effects of the source of inco...

  4. Surveying Education

    DEFF Research Database (Denmark)

    Enemark, Stig

    2009-01-01

    In relation to surveying education there is one big question to be asked: Is the role of the surveyors changing? In a global perspective the answer will be "Yes". There is a big swing that could be entitled "From Measurement to Management". This does not imply that measurement is no longer....... In surveying education there are a range of other challenges to be faced. These relate to the focus on learning to learn; the need for flexible curriculum to deal with constant change; the move towards introducing virtual academy; the demand for creating a quality culture; and the perspective of lifelong...... on an efficient interaction between education, research, and professional practice....

  5. An alternative longitudinal polarization scheme for tristan

    International Nuclear Information System (INIS)

    Chao, A.W.; Yokoya, Kaoru.

    1981-07-01

    For electron storage rings general conditions are derived to get a high level longitudinal polarization and a possible design of the experimental insertion for TRISTAN e-p collider is presented. (author)

  6. Longitudinal beam dynamics at transition crossing

    Energy Technology Data Exchange (ETDEWEB)

    Bogacz, S.A.

    1991-11-01

    A brief outline of the longitudinal single particle dynamics at transition is presented in terms of phase-space mappings. Simple quantitative prediction about the phase-space dilution is made. More realistic simulation (ESME) of the transition crossing is carried out (including various collective and single particle effects contributing to the longitudinal emittance blow up). The simulation takes into account the longitudinal space-charge force (bunch length oscillation), the transverse space-charge (the Umstaetter effect) and finally the dispersion of the momentum compaction factor (the Johnsen effect). As a result of this simulation one can separate relative strengths of the above mechanisms and study their individual effects on the longitudinal phase-space evolution, especially filamentation of the bunch and formation of a galaxy-like'' pattern. 7 refs., 2 figs.

  7. Energy dissipation by a longitudinal Raman process

    International Nuclear Information System (INIS)

    Fano, U.; Inokuti, Mitio

    1994-01-01

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

  8. Multilevel Cross-Dependent Binary Longitudinal Data

    KAUST Repository

    Serban, Nicoleta; Staicu, Ana-Maria; Carroll, Raymond J.

    2013-01-01

    processes describing the within- and between-variability, and describing the cross-dependence of the repeated longitudinal measurements. We estimate the model components without employing mixed-effects modeling but assuming an approximation to the logistic

  9. Longitudinal and transverse wake potentials in SLAC

    International Nuclear Information System (INIS)

    Bane, K.; Wilson, P.

    1980-01-01

    In a machine with short bunches of high peak currents, such as the SLAC collider, one needs to know the longitudinal wake potential, for the higher mode losses, and the transverse wake potential, since, for bunches passing slightly off axis, the induced transverse forces will tend to cause beam break up. The longitudinal and transverse wakes of the SLAC structure presented here, were calculated by computer using the modal method, and including an analytic extension for higher modes. (Auth.)

  10. Longitudinal Risk Factors for Cyberbullying in Adolescence

    OpenAIRE

    Sticca, Fabio; Ruggieri, Sabrina; Alsaker, Françoise; Perren, Sonja

    2013-01-01

    Cyberbullying has emerged as a new form of antisocial behaviour in the context of online communication over the last decade. The present study investigates potential longitudinal risk factors for cyberbullying. A total of 835 Swiss seventh graders participated in a short-term longitudinal study (two assessments 6 months apart). Students reported on the frequency of cyberbullying, traditional bullying, rule-breaking behaviour, cybervictimisation, traditional victimisation, and frequency of onl...

  11. Nonlinear longitudinal dynamics studies at the ALS

    International Nuclear Information System (INIS)

    Byrd, J.M.; Cheng, W.-H.; De Santis, S.; Li, D.; Stupakov, G.; Zimmermann, F.

    1999-01-01

    We present a summary of results for a variety of studies of nonlinear longitudinal dynamics in the Advanced Light Source, an electron storage ring. These include observation of decoherence at injection, decay of an injected beam, forced synchrotron oscillations and diffusion from one bunch to the next. All of the measurements were made using a dual-scan streak camera which allowed the real-time observation of the longitudinal distribution of the electron beam

  12. Environmental surveys

    International Nuclear Information System (INIS)

    Costa-Ribeiro, C.

    1977-01-01

    An environmental survey conducted in high natural radioactivity areas and methods used to evaluated radiation doses received by the population are presented. It is shown doses absorved due to ingestion of radioactively contaminated food and water. Exposure to external gamma radiation fields or inhalation of abnormal quantities of natural airborne radioactivity are discussed [pt

  13. Survey < > Creation

    DEFF Research Database (Denmark)

    2017-01-01

    The project, Survey Creation suggests that point cloud models from 3D scans of an existing space can be the source for explorative drawings. By probing into the procedure of 3D laser scanning, it became possible to make use of the available point clouds to both access geometric representation......) and the creation drawing (of the anticipated)....

  14. Longitudinal associations between parenting style and adolescent disordered eating behaviors.

    Science.gov (United States)

    Zubatsky, Max; Berge, Jerica; Neumark-Sztainer, Dianne

    2015-06-01

    The main purpose of this study was to identify the longitudinal association between specific parenting styles (authoritarian, authoritative, permissive, and neglectful) and adolescent disordered eating behaviors. The current study uses longitudinal data from a 5-year study to examine the associations between parenting style and disordered eating behaviors among adolescents. Data from adolescents (n = 2516) participating in Project EAT (Eating Among Teens), a population-based study from 31 Minnesota schools, were used in the analysis. Time 1 data were collected using in-class assessments of adolescents from Minneapolis/St. Paul schools, and Time 2 data were collected using mailed surveys 5 years later. General Linear Models were used to predict adolescent-reported disordered eating behaviors at Time 2 from adolescent-reported parenting style at Time 1. Adolescent boys and girls who had authoritarian mothers at Time 1 had a higher probability of extreme weight control behaviors 5 years later compared to adolescents with authoritative, permissive, or neglectful mothers. Adolescent girls with authoritarian mothers at Time 1 had a higher probability of engaging in binge-eating behaviors at Time 2 compared to adolescent girls with authoritative or permissive mothers. There were no significant associations between paternal parenting style and adolescent disordered eating behaviors. Although authoritarian parenting style served as a possible risk factor for disordered eating behaviors in adolescents, the findings were not conclusive. Future studies should investigate further the association between parenting style and weight control behaviors in adolescents.

  15. Readership survey

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

    The article reviews the last readership survey, which helped to check readers' reactions and the level and style of the journal. The majority of readers (32 per cent), not surprisingly, work in high energy physics. In fact, if the estimate of the world high energy physics population as some 5000 people is correct, CERN Courier reaches every one of them. The next large category of readers is the teaching profession (21 percent), with industrialists (12 per cent) in third place

  16. Overview of national attitudes toward nuclear energy: a longitudinal analysis

    International Nuclear Information System (INIS)

    Rankin, W.L.

    1982-01-01

    The purpose of this paper is to present a longitudinal overview of public attitudes toward nuclear power development in the United States. Over ten years of attitudinal data are now available for analysis of the stability of such attitudes over time. These data are useful to many people, including policy makers in government, nuclear industry decision makers, and public action groups that support and oppose nuclear power. This information is also useful in checking the claims of those who purport to be speaking for the public. The level of public acceptance for nuclear power in the near term and into the next century can only be estimated at this time. But this estimate can be based on nearly a decade of survey research

  17. Development of materialism in adolescence: The longitudinal role of life satisfaction among Chinese youths

    OpenAIRE

    Ku, L.

    2014-01-01

    The present research tests the longitudinal role of life satisfaction on materialism among Chinese adolescents, and provides empirical evidence to support the theorisation that materialism develops as compensation for dissatisfaction with life. Study 1 establishes that the negative relationship between life satisfaction and materialism is present and similar among the younger (N = 516; M = 12.94 years) and the older adolescents (N = 531; M = 16.57 years). A two-wave survey (Study 2) finds no ...

  18. The Relationship Between Marijuana Use and Intimate Partner Violence in a Nationally Representative, Longitudinal Sample

    OpenAIRE

    Reingle, Jennifer M.; Staras, Stephanie A. S.; Jennings, Wesley G.; Branchini, Jennifer; Maldonado-Molina, Mildred M.

    2011-01-01

    Intimate partner violence is a significant public health problem, as these behaviors have been associated with a number of negative health outcomes including illicit drug use, physical injury, chronic pain, sexually transmitted diseases, depression, and posttraumatic stress disorder. The current study examined the association between marijuana use and intimate partner violence using a longitudinal survey of adolescents and young adults ages 15 to 26 years. Data were obtained from 9,421 adoles...

  19. Recovery from social phobia in the community and its predictors : data from a longitudinal epidemiological study

    OpenAIRE

    Vriends, N.; Becker, E. S.; Meyer, A. H.; Williams, S. L.; Lutz, R.; Margraf, J.

    2007-01-01

    The present longitudinal study aimed to determine rate of natural recovery from DSM-IV social phobia in the community and to examine predictors of recovery. Data were derived from the Dresden Predictor Study of a representative sample of 1396 young German women. The participants completed a diagnostic interview and self-report questionnaires at two survey points approximately 1.5 years apart. Of the 91 women with social phobia at baseline 64% were at least partially recovered and 36% showed f...

  20. A Longitudinal Examination of the Role of Stereotype Threat and Racial Climate on College Outcomes for Minorities at Elite Institutions

    Science.gov (United States)

    Fischer, Mary J.

    2010-01-01

    This paper employs hierarchical linear models to explore the long-term effects of stereotype threat on college outcomes for students in the National Longitudinal Survey of Freshmen. Performance burden was negatively related to both grades and social satisfaction with college. Social satisfaction with college was also significantly impacted by…

  1. The Role of Personal Best (PB) and Dichotomous Achievement Goals in Students' Academic Motivation and Engagement: A Longitudinal Investigation

    Science.gov (United States)

    Martin, Andrew J.; Elliot, Andrew J.

    2016-01-01

    This study assessed the role of prior personal best goals in predicting subsequent academic motivation and engagement. A total of 1160 high school students participated in a longitudinal survey study exploring the extent to which personal best and mastery and performance (dichotomous) achievement goals predict students' academic motivation and…

  2. Concurrent and Longitudinal Effects of Ethnic Identity and Experiences of Discrimination on Psychosocial Adjustment of Navajo Adolescents

    Science.gov (United States)

    Galliher, Renee V.; Jones, Matthew D.; Dahl, Angie

    2011-01-01

    In this study, we examined concurrent and longitudinal relations among Navajo adolescents' ethnic identity, experiences of discrimination, and psychosocial outcomes (i.e., self-esteem, substance use, and social functioning). At Time 1, 137 Navajo adolescents (67 male, 70 female), primarily in Grades 9 and 10, completed a written survey assessing…

  3. Longitudinal fluctuations and decorrelation of anisotropic flow

    Energy Technology Data Exchange (ETDEWEB)

    Pang, Long-Gang [Frankfurt Institute for Advanced Studies, Ruth-Moufang-Strasse 1, 60438 Frankfurt am Main (Germany); Petersen, Hannah [Frankfurt Institute for Advanced Studies, Ruth-Moufang-Strasse 1, 60438 Frankfurt am Main (Germany); Institute for Theoretical Physics, Goethe University, Max-von-Laue-Strasse 1, 60438 Frankfurt am Main (Germany); GSI Helmholtzzentrum für Schwerionenforschung, Planckstr. 1, 64291 Darmstadt (Germany); Qin, Guang-You [Key Laboratory of Quark & Lepton Physics (MOE) and Institute of Particle Physics, Central China Normal University, Wuhan 430079 (China); Roy, Victor [Institute for Theoretical Physics, Goethe University, Max-von-Laue-Strasse 1, 60438 Frankfurt am Main (Germany); Wang, Xin-Nian [Key Laboratory of Quark & Lepton Physics (MOE) and Institute of Particle Physics, Central China Normal University, Wuhan 430079 (China); Nuclear Science Division MS70R0319, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

    2016-12-15

    We investigate the decorrelation of 2nd and 3rd order anisotropic flow for charged particles in two different pseudo rapidity (η) windows by varying the pseudo rapidity gap, in an event-by-event (3+1)D ideal hydrodynamic model, with fluctuating initial conditions from A Multi-Phase Transport (AMPT) model. We visualize the parton distribution at initial state for Pb+Pb collisions at LHC and Au+Au collisions at RHIC, and demonstrate the longitudinal fluctuations originating from the asymmetry between forward and backward going participants, the fluctuations of the string length and the fluctuations due to finite number of partons at different beam energies. The decorrelation of anisotropic flow of final hadrons with large η gaps is found to originate from the spatial decorrelation along the longitudinal direction in the AMPT initial conditions through hydrodynamic evolution. The agreement between our results and recent CMS data in most centralities suggests that the string-like mechanism of initial parton production in AMPT model captures the initial longitudinal fluctuation that is responsible for the measured decorrelation of anisotropic flow in Pb+Pb collisions at LHC. Our predictions for Au+Au collisions at the highest RHIC energy show stronger longitudinal decorrelation than at LHC, indicating larger longitudinal fluctuations at lower beam energies.

  4. Study of CSR longitudinal bunch compression cavity

    International Nuclear Information System (INIS)

    Yin Dayu; Li Peng; Liu Yong; Xie Qingchun

    2009-01-01

    The scheme of longitudinal bunch compression cavity for the Cooling Storage Ring (CSR)is an important issue. Plasma physics experiments require high density heavy ion beam and short pulsed bunch,which can be produced by non-adiabatic compression of bunch implemented by a fast compression with 90 degree rotation in the longitudinal phase space. The phase space rotation in fast compression is initiated by a fast jump of the RF-voltage amplitude. For this purpose, the CSR longitudinal bunch compression cavity, loaded with FINEMET-FT-1M is studied and simulated with MAFIA code. In this paper, the CSR longitudinal bunch compression cavity is simulated and the initial bunch length of 238 U 72+ with 250 MeV/u will be compressed from 200 ns to 50 ns.The construction and RF properties of the CSR longitudinal bunch compression cavity are simulated and calculated also with MAFIA code. The operation frequency of the cavity is 1.15 MHz with peak voltage of 80 kV, and the cavity can be used to compress heavy ions in the CSR. (authors)

  5. Longitudinal Electroproduction of Charged Pions from

    International Nuclear Information System (INIS)

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

    2001-01-01

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

  6. Longitudinal magnetoresistance and magnototermopower in Bi nanowires

    International Nuclear Information System (INIS)

    Para, G.

    2011-01-01

    Full text: The galvanomagnetic effect of single crystals Bi nanowires have been studied in longitudinal magnetic fields up to 14 T. The influence of diameters, temperature and deformation extension on the longitudinal magnetoresistance and magnetotermopower (H||I, H||ΔT) of bismuth nanowires is studied. Elastic deformation measurements were conducted at maximum relative elongation 2 %. For the first time have been investigated the magnetotermopower of Bi nanowires with d=45 nm. Essentially non monotonic dependence H max on temperature in longitudinal thermopower in wires with d=45-60 nm is found out. Such difference in behavior of maximum on R(H) and on α(H) in wires with d<100nm says that the behavior of resistance is caused by other mechanism, then thermopower. (author)

  7. Large Scale Survey Data in Career Development Research

    Science.gov (United States)

    Diemer, Matthew A.

    2008-01-01

    Large scale survey datasets have been underutilized but offer numerous advantages for career development scholars, as they contain numerous career development constructs with large and diverse samples that are followed longitudinally. Constructs such as work salience, vocational expectations, educational expectations, work satisfaction, and…

  8. Multiple Surveys of Students and Survey Fatigue

    Science.gov (United States)

    Porter, Stephen R.; Whitcomb, Michael E.; Weitzer, William H.

    2004-01-01

    This chapter reviews the literature on survey fatigue and summarizes a research project that indicates that administering multiple surveys in one academic year can significantly suppress response rates in later surveys. (Contains 4 tables.)

  9. Longitudinal Mediation Modeling of Unhealthy Behaviors as Mediators between Workplace Demands/Support and Depressive Symptoms.

    Science.gov (United States)

    Magnusson Hanson, Linda L; Peristera, Paraskevi; Chungkham, Holendro Singh; Westerlund, Hugo

    2016-01-01

    Lifestyle has been regarded as a key pathway through which adverse psychosocial working characteristics can give rise to long-term health problems. The purpose of this study was to estimate the indirect/mediated effect of health behaviors in the longitudinal work characteristics-depression relationship. The analyses were based on the Swedish Longitudinal Occupational Survey of Health, including 3706 working participants with repeat survey measures on four occasions (2008, 2010, 2012 and 2014). Psychosocial work characteristics including demands and social support were analyzed in relation to depressive symptoms. Autoregressive longitudinal mediation models using structural equation modeling were used to estimate the intermediate effects of unhealthy behaviors including current smoking, excessive alcohol consumption, unhealthy diet and physical inactivity. Both workplace demands and social support were related to later depressive symptoms. In bivariate models we found no significant paths from workplace demands to health behaviors, but two out of three significant time-specific paths from workplace support to excessive drinking and from excessive drinking to depressive symptoms. Social support was also associated with subsequent unhealthy diet, and one path from unhealthy diet to depressive symptoms was found. However, despite indications of certain longitudinal relationships between psychosocial working conditions and health behaviors as well as between health behaviors and depressive symptoms, no significant intermediate effects were found (p>0.05). We conclude that changes in unhealthy behaviors over a period of two years are unlikely to act as strong intermediaries in the longitudinal relationship between job demands and depressive symptoms and between social support and depressive symptoms.

  10. Longitudinal Mediation Modeling of Unhealthy Behaviors as Mediators between Workplace Demands/Support and Depressive Symptoms

    Science.gov (United States)

    Magnusson Hanson, Linda L.; Peristera, Paraskevi; Chungkham, Holendro Singh; Westerlund, Hugo

    2016-01-01

    Lifestyle has been regarded as a key pathway through which adverse psychosocial working characteristics can give rise to long-term health problems. The purpose of this study was to estimate the indirect/mediated effect of health behaviors in the longitudinal work characteristics-depression relationship. The analyses were based on the Swedish Longitudinal Occupational Survey of Health, including 3706 working participants with repeat survey measures on four occasions (2008, 2010, 2012 and 2014). Psychosocial work characteristics including demands and social support were analyzed in relation to depressive symptoms. Autoregressive longitudinal mediation models using structural equation modeling were used to estimate the intermediate effects of unhealthy behaviors including current smoking, excessive alcohol consumption, unhealthy diet and physical inactivity. Both workplace demands and social support were related to later depressive symptoms. In bivariate models we found no significant paths from workplace demands to health behaviors, but two out of three significant time-specific paths from workplace support to excessive drinking and from excessive drinking to depressive symptoms. Social support was also associated with subsequent unhealthy diet, and one path from unhealthy diet to depressive symptoms was found. However, despite indications of certain longitudinal relationships between psychosocial working conditions and health behaviors as well as between health behaviors and depressive symptoms, no significant intermediate effects were found (p>0.05). We conclude that changes in unhealthy behaviors over a period of two years are unlikely to act as strong intermediaries in the longitudinal relationship between job demands and depressive symptoms and between social support and depressive symptoms. PMID:28036376

  11. Magnetic field of longitudinal gradient bend

    Science.gov (United States)

    Aiba, Masamitsu; Böge, Michael; Ehrlichman, Michael; Streun, Andreas

    2018-06-01

    The longitudinal gradient bend is an effective method for reducing the natural emittance in light sources. It is, however, not a common element. We have analyzed its magnetic field and derived a set of formulae. Based on the derivation, we discuss how to model the longitudinal gradient bend in accelerator codes that are used for designing electron storage rings. Strengths of multipole components can also be evaluated from the formulae, and we investigate the impact of higher order multipole components in a very low emittance lattice.

  12. Simulations of longitudinally pumped dye laser amplifier

    International Nuclear Information System (INIS)

    Takehisa, Kiwamu; Takemori, Satoshi

    1995-01-01

    Simulations of a copper laser pumped dye laser amplifier and new designs of the longitudinally pumped dye laser amplifier are presented. The simulations take the consideration of the amplified spontaneous emission (ASE). The new designs utilize a center-hole reflector instead of a dichroic mirror. The simulation results indicate that the poor spatial overlap between the pump beam and the dye beam in the transverse pumping not only reduces the laser output power, but also generates ASE strongly. The results also indicate that the longitudinal pumping is as efficient as the transverse pumping. (author)

  13. Longitudinal tibial epiphyseal bracket in Nievergelt syndrome

    International Nuclear Information System (INIS)

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

    1989-01-01

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

  14. Longitudinal tibial epiphyseal bracket in Nievergelt syndrome

    Energy Technology Data Exchange (ETDEWEB)

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

    1989-04-01

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

  15. Longitudinal and bulk viscosities of expanded rubidium

    International Nuclear Information System (INIS)

    Zaheri, Ali Hossein Mohammad; Srivastava, Sunita; Tankeshwar, K

    2003-01-01

    First three non-vanishing sum rules for the bulk and longitudinal stress auto-correlation functions have been evaluated for liquid Rb at six thermodynamic states along the liquid-vapour coexistence curve. The Mori memory function formalism and the frequency sum rules have been used to calculate bulk and longitudinal viscosities. The results thus obtained for the ratio of bulk viscosity to shear viscosity have been compared with experimental and other theoretical predictions wherever available. The values of the bulk viscosity have been found to be more than the corresponding values of the shear viscosity for all six thermodynamic states investigated here

  16. Reader survey

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1993-10-15

    Many, thanks to the hundreds of people who took the time to reply to the CERN Courier readership survey questionnaire published in our May issue. Bringing out a monthly journal is a lonely business. Issue after issue goes out, and the only response is when there's an occasional factual error. Send out a readership survey and a faint echo comes back. Most striking was the sheer enthusiasm of the replies. Despite the current erosion of support in the US (see page 2), subatomic physics has significant world-wide box-office appeal. Most important was to find out who our readers are. 61% of the replies came from Europe, 21% from the USA, 14% from elsewhere, (including the former Soviet Union), and 4% from inside CERN. Not surprisingly, the main audience (37%) is in the high energy physics sector. Then comes teaching (31%), followed closely by accelerators operations and design (12%) and industry (11%). Apart from detailed breakdowns of readership and feedback on the journal's content and style, the replies revealed several major features. Firstly, the CERN Courier is widely read and appreciated. There are a lot of people outside the immediate research field who want to keep broadly up to date with the latest developments in high energy physics and related fields, without getting too involved in details. It was gratifying to receive replies from far-flung places (Nepal, Indonesia,....), and learn how much distant readers appreciate getting such regular information. 'It helps us feel part of the world scene,' was a typical such reply, from Australia. Despite jet airplanes, fax and electronic mail, our planet is still big.

  17. Reader survey

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    Many, thanks to the hundreds of people who took the time to reply to the CERN Courier readership survey questionnaire published in our May issue. Bringing out a monthly journal is a lonely business. Issue after issue goes out, and the only response is when there's an occasional factual error. Send out a readership survey and a faint echo comes back. Most striking was the sheer enthusiasm of the replies. Despite the current erosion of support in the US (see page 2), subatomic physics has significant world-wide box-office appeal. Most important was to find out who our readers are. 61% of the replies came from Europe, 21% from the USA, 14% from elsewhere, (including the former Soviet Union), and 4% from inside CERN. Not surprisingly, the main audience (37%) is in the high energy physics sector. Then comes teaching (31%), followed closely by accelerators operations and design (12%) and industry (11%). Apart from detailed breakdowns of readership and feedback on the journal's content and style, the replies revealed several major features. Firstly, the CERN Courier is widely read and appreciated. There are a lot of people outside the immediate research field who want to keep broadly up to date with the latest developments in high energy physics and related fields, without getting too involved in details. It was gratifying to receive replies from far-flung places (Nepal, Indonesia,....), and learn how much distant readers appreciate getting such regular information. 'It helps us feel part of the world scene,' was a typical such reply, from Australia. Despite jet airplanes, fax and electronic mail, our planet is still big

  18. Benefits and Burdens of Participation in a Longitudinal Clinical Trial

    Science.gov (United States)

    Lazovski, Jaime; Losso, Marcelo; Krohmal, Benjamin; Emanuel, Ezekiel J.; Grady, Christine; Wendler, David

    2010-01-01

    systematic data on the impact that longitudinal clinical trials have on patient participants are needed to ensure that all the risks and potential benefits of participating in clinical research are properly evaluated and disclosed. Recognizing the lack of systematic data on this topic, we surveyed 582 individuals from Argentina, Brazil, and Thailand who were participating in the ESPRIT study, a Phase III randomized trial of interleukin-2 in HIV disease. Respondents were asked about the benefits and burdens of participating in ESPRIT using a self-administered survey. We found that 91% of respondents in the IL-2 treatment arm and 79% in the no IL-2 control arm reported medical benefits from their participation. In addition, 68% in the IL-2 treatment arm and 60% of the no IL-2 controls reported non-medical benefits. Thirteen percent of the IL-2 respondents and 5% of the non-IL2 respondents reported problems with their jobs due to study participation. Given that respondents, including those in the control arm, reported medical and non-medical benefits and burdens from their research participation, investigators and review committees should be aware of and respond to the potential for research participants to experience benefits and burdens that are unrelated to the intervention being tested. PMID:19754238

  19. Collaborative Knowledge-Building: A Longitudinal Study

    Science.gov (United States)

    Li, Qing

    2009-01-01

    The focus of this paper is on knowledge-building in a technology-supported learning environment in higher education through a longitudinal study of a graduate course from 2003 to 2007. The primary question is: how do learning conditions designed into a graduate course contribute to collaborative knowledge building? In particular, two major…

  20. Are Sibling Relationships Protective? A Longitudinal Study

    Science.gov (United States)

    Gass, Krista; Jenkins, Jennifer; Dunn, Judy

    2007-01-01

    Background: Although the protective effects of familial and parental support have been studied extensively in the child psychopathology literature, few studies have explored the protective quality of positive sibling relationships. Methods: A two-wave longitudinal design was used to examine the protective effect of positive sibling relationships…

  1. Advection models of longitudinal dispersion in rivers

    NARCIS (Netherlands)

    Kranenburg, C.

    1996-01-01

    A derivation is presented of a general cross-section averaged model of longitudinal dispersion, which is based on the notion of the advection of tracer particles. Particle displacement length and particle travel time are conceived as stochastic variables, and a joint probability density function is

  2. The Czech longitudinal study of optimal development

    Czech Academy of Sciences Publication Activity Database

    Kebza, V.; Šolcová, Iva; Kodl, M.; Kernová, V.

    2012-01-01

    Roč. 47, Suppl. 1 (2012), s. 266-266 ISSN 0020-7594. [International Congress of Psychology /30./. 22.07.2012-27.07.2012, Cape Town] R&D Projects: GA ČR GAP407/10/2410 Institutional support: RVO:68081740 Keywords : optimal development * Prague longitudinal study Subject RIV: AN - Psychology

  3. Longitudinal myelitis associated with yellow fever vaccination.

    Science.gov (United States)

    Chaves, M; Riccio, P; Patrucco, L; Rojas, J I; Cristiano, E

    2009-07-01

    Severe adverse reaction to yellow fever (YF) vaccine includes the yellow fever vaccine-associated neurotropic disease. This terminology includes postvaccinal encephalitis, acute disseminated encephalomyelitis, and Guillain-Barré syndrome. The objective of this communication is to report a patient who received a YF vaccine in Argentina and subsequently developed longitudinal myelitis with a symptom that had previously gone unreported in the literature. A 56-year-old man began with progressive paraparesia, urinary retention, and constipation 48 h previous to admission. The patient received YF vaccine 45 days prior to the onset of the symptoms. There was no history of other immunization or relevant condition. MR of the spine showed longitudinal intramedullary hyperintense signal (D5-12) without gadolinium enhancement. A high concentration of YFV-specific IgM vaccine antibody was found in the cerebrospinal fluid (CSF). Serological tests for other flavivirus were negative. A diagnosis of longitudinal myelitis without encephalitis associated with YF vaccine was performed and symptoms improved 5 days later. This is the first report dealing with longitudinal myelitis as a serious adverse event associated with YF vaccination in which confirmation of the presence of antibodies in CSF was found. To date, it is also the first report with serological confirmation in Argentina and in South America. We consider that the present investigation will raise awareness in the region in the reporting of adverse events related to YF vaccine and improve our knowledge of adverse reactions to the vaccine.

  4. Longitudinal Predictors of High School Completion

    Science.gov (United States)

    Barry, Melissa; Reschly, Amy L.

    2012-01-01

    This longitudinal study examined predictors of dropout assessed in elementary school. Student demographic data, achievement, attendance, and ratings of behavior from the Behavior Assessment System for Children were used to predict dropout and completion. Two models, which varied on student sex and race, predicted dropout at rates ranging from 75%…

  5. The Merits of Using Longitudinal Mediation

    Science.gov (United States)

    Jose, Paul E.

    2016-01-01

    Many of the mediation analyses reported in the literature are based on concurrent or single-occasion data sets. The 2 overarching themes of the present article are: Results of concurrent mediations are inherently ambiguous, and researchers would be wise to conduct mediations on longitudinal data sets instead. An example included here demonstrates…

  6. Statistical Power in Longitudinal Network Studies

    NARCIS (Netherlands)

    Stadtfeld, Christoph; Snijders, Tom A. B.; Steglich, Christian; van Duijn, Marijtje

    2018-01-01

    Longitudinal social network studies may easily suffer from a lack of statistical power. This is the case in particular for studies that simultaneously investigate change of network ties and change of nodal attributes. Such selection and influence studies have become increasingly popular due to the

  7. Development of longitudinally excited CO2 laser

    Science.gov (United States)

    Masroon, N. S.; Tanaka, M.; Tei, M.; Uno, K.; Tsuyama, M.; Nakano, H.

    2018-05-01

    Simple, compact, and affordable discharged-pumped CO2 laser controlled by a fast high voltage solid state switch has been developed. In this study, longitudinal excitation scheme has been adapted for simple configuration. In the longitudinal excitation scheme, the discharge is produced along the direction of the laser axis, and the electrodes are well separated with a small discharge cross-section. Triggered spark gap switch is usually used to switch out the high voltage because of simple and low cost. However, the triggered spark gap operates in the arc mode and suffer from recovery problem causing a short life time and low efficiency for high repetition rate operation. As a result, there is now considerable interest in replacing triggered spark gap switch with solid state switches. Solid state switches have significant advantages compared to triggered spark gap switch which include longer service lifetime, low cost and stable high trigger pulse. We have developed simple and low cost fast high voltage solid state switch that consists of series connected-MOSFETs. It has been installed to the longitudinally excited CO2 laser to realize the gap switch less operation. Characteristics of laser oscillation by varying the discharge length, charging voltage, capacitance and gas pressure have been evaluated. Longer discharge length produce high power of laser oscillation. Optimum charging voltage and gas pressure were existed for longitudinally excited CO2 laser.

  8. Longitudinal bulk a coustic mass sensor

    DEFF Research Database (Denmark)

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

    2009-01-01

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

  9. Heat production: Longitudinal versus torsional phacoemulsification.

    Science.gov (United States)

    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.

  10. Burnout development among dentists : a longitudinal study

    NARCIS (Netherlands)

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

    2008-01-01

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

  11. Boosted Multivariate Trees for Longitudinal Data

    Science.gov (United States)

    Pande, Amol; Li, Liang; Rajeswaran, Jeevanantham; Ehrlinger, John; Kogalur, Udaya B.; Blackstone, Eugene H.; Ishwaran, Hemant

    2017-01-01

    Machine learning methods provide a powerful approach for analyzing longitudinal data in which repeated measurements are observed for a subject over time. We boost multivariate trees to fit a novel flexible semi-nonparametric marginal model for longitudinal data. In this model, features are assumed to be nonparametric, while feature-time interactions are modeled semi-nonparametrically utilizing P-splines with estimated smoothing parameter. In order to avoid overfitting, we describe a relatively simple in sample cross-validation method which can be used to estimate the optimal boosting iteration and which has the surprising added benefit of stabilizing certain parameter estimates. Our new multivariate tree boosting method is shown to be highly flexible, robust to covariance misspecification and unbalanced designs, and resistant to overfitting in high dimensions. Feature selection can be used to identify important features and feature-time interactions. An application to longitudinal data of forced 1-second lung expiratory volume (FEV1) for lung transplant patients identifies an important feature-time interaction and illustrates the ease with which our method can find complex relationships in longitudinal data. PMID:29249866

  12. Teaching Technology Longitudinally to Virtual Children

    Science.gov (United States)

    Matthews, Lynley

    2010-01-01

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

  13. Residents’ perceptions of an integrated longitudinal curriculum: a qualitative study

    Directory of Open Access Journals (Sweden)

    Rebecca Lubitz

    2015-12-01

    Conclusions: This study suggests that an integrated longitudinalized family medicine block training model has the potential to support the principles of a longitudinal integrated competency-based curriculum to effectively prepare residents for family medicine practice.

  14. Literature survey

    International Nuclear Information System (INIS)

    Drury, J.S.; Michelson, D.; Ensminger, J.T.

    1982-01-01

    Literature was searched for methods of removing uranium from drinking water. No relevant papers were found, but approximately 1000 publications were identified in a less specific search for methods of removing uranium from water. Most of the latter publications dealt with the recovery of uranium from ores, industrial and analytical chemistry solutions, or seawater. The conditions under which these studies were performed were usually quite different from those normally occurring in municipal water treatment practice, but some potentially interesting systems of recovery were identified. A few papers addressed the problem of removing uranium from natural fresh waters and established the effectiveness of using adsorbents or coprecipitants, such as aluminum hydroxide, ferric hydroxide, activated carbon, and ion exchangers, under certain conditions. Also, many US manufacturers and users of water treatment equipment and products were contacted regarding recommended methods of removing uranium from potable water. Based on the results of these surveys, it is recommended that untreated, partially treated, and finished water samples from municipal water treatment facilities be analyzed to determine their extent of removal of uranium by presently used procedures. In addition, laboratory studies are suggested to determine what changes, if any, are needed to maximize the effectiveness of treatments that are already in use in existing water treatment plants

  15. 46 CFR 154.176 - Longitudinal contiguous hull structure.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Longitudinal contiguous hull structure. 154.176 Section... Equipment Hull Structure § 154.176 Longitudinal contiguous hull structure. (a) The longitudinal contiguous hull structure of a vessel having cargo containment systems without secondary barriers must meet the...

  16. Ring RF and longitudinal dynamics in the SNS

    International Nuclear Information System (INIS)

    Blaskiewicz, M.; Brennan, J.M.; Brodowski, J.; Delong, J.; Meth, M.; Onillon, E.; Zaltsman, A.

    2000-01-01

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

  17. Existence of longitudinal waves in pre-stressed anisotropic elastic ...

    Indian Academy of Sciences (India)

    waves is truly longitudinal. Longitudinal wave in an anisotropic elastic medium is defined as the wave motion in which the particle motion (i.e., the. Keywords. General anisotropy; elastic stiffness; pre-stress; group velocity; ray direction; longitudinal waves; polarization. J. Earth Syst. Sci. 118, No. 6, December 2009, pp. 677– ...

  18. Longitudinal Emergency Medical Technician Attributes and Demographic Study (LEADS) Design and Methodology.

    Science.gov (United States)

    Levine, Roger

    2016-12-01

    The objective of this study is to describe the Longitudinal Emergency Medical Technician (EMT) Attributes and Demographic Study (LEADS) design, instrument development, pilot testing, sampling procedures, and data collection methodology. Response rates are provided, along with results of follow-up surveys of non-responders (NRs) and a special survey of Emergency Medical Services (EMS) professionals who were not nationally certified. Annual surveys from 1999 to 2008 were mailed out to a random, stratified sample of nationally registered EMT-Basics and Paramedics. Survey weights were developed to reflect each respondent's probability of selection. A special survey of NRs was mailed out to individuals who did not respond to the annual survey to estimate the probable extent and direction of response bias. Individuals who indicated they were no longer in the profession were mailed a special exit survey to determine their reasons for leaving EMS. Given the large number of comparisons between NR and regular (annual) survey respondents, it is not surprising that some statistically significant differences were found. In general, there were few differences. However, NRs tended to report higher annual EMS incomes, were younger, healthier, more physically fit, and were more likely to report that they were not practicing EMS. Comparisons of the nationally certified EMS professionals with EMS professionals who were not nationally certified indicated that nationally certified EMS providers were younger, had less EMS experiences, earned less, were more likely to be female and work for private EMS services, and less likely to work for fire-based services. These differences may reflect state and local policy and practice, since many states and local agencies do not require maintenance of national certification as a requirement to practice. When these differences were controlled for statistically, there were few systematic differences between non-nationally certified and nationally

  19. Evaluation of longitudinal loading of tank trains during motion in longitudinal changes of gradient

    Directory of Open Access Journals (Sweden)

    S.V. Myamlin

    2013-06-01

    Full Text Available Purpose. To research the tank train longitudinal loading during motion by track sections with changes of gradient. The trains of different length that consist of bogie tank wagons should be examined. Influence of cargo type on longitudinal loading of train during motion in concave section of track should be evaluated. Methodology. The level of the largest longitudinal forces was estimated by mathematical simulation. It was assumed that change of gradient is formed by two grades with baffle platforms, length 50 meters, so that the algebraic difference of limiting grades vary from 10‰ to 40‰, pitch 10‰. The initial speeds were 40, 60, 80, 100, 120 km/h. For evaluation of the longitudinal loading the regulating braking and motion "by coasting" was considered. For evaluation of buffing loads the entry to the concave gradient change of expanded train is considered, and in order to determine the quasi-static forces the compressed train is considered. Findings. As a result of calculations the dependencies of maximal longitudinal forces in the trains on the cargo type, the algebraic difference of the grades, the number of tank wagons, the initial speed, motion modes, and initial gaps condition in the train were obtained. Originality. The longitudinal loading of freight cars of different length formed by the similar bogie tank wagons with one locomotive was obtained. The locomotive is placed in the train head during motion in concave track sections with various algebraic difference of the grades "on coasting" and during the regulating braking mode. The obtained results can be used for parameters standardization of profile elevation of the track. Practical value. The obtained results show that during operation of tank trains on track sections of complex breakage the most dangerous is regulating braking of preliminary compressed trains during entering on concave parts of track. Level of the greatest buffing and quasi-static longitudinal forces is

  20. Longitudinal Control for Mengshi Autonomous Vehicle via Cloud Model

    Science.gov (United States)

    Gao, H. B.; Zhang, X. Y.; Li, D. Y.; Liu, Y. C.

    2018-03-01

    Dynamic robustness and stability control is a requirement for self-driving of autonomous vehicle. Longitudinal control method of autonomous is a key technique which has drawn the attention of industry and academe. In this paper, we present a longitudinal control algorithm based on cloud model for Mengshi autonomous vehicle to ensure the dynamic stability and tracking performance of Mengshi autonomous vehicle. An experiments is applied to test the implementation of the longitudinal control algorithm. Empirical results show that if the longitudinal control algorithm based Gauss cloud model are applied to calculate the acceleration, and the vehicles drive at different speeds, a stable longitudinal control effect is achieved.

  1. Longitudinal momentum distributions in transverse coordinate space

    International Nuclear Information System (INIS)

    Kumar, Narinder; Mondal, Chandan

    2016-01-01

    In the present work, we study the longitudinal momentum distributions in the transverse coordinate space in a light-front quark-diquark model inspired by soft-wall AdS/QCD. We take the phenomenological light-front quark-diquark model proposed by Gutsche et. al. In this model, the light-front wave functions (LFWFs) for the proton are constructed from the two particle wave functions obtained in soft-wall AdS/QCD

  2. Space Charge Mitigation With Longitudinally Hollow Bunches

    CERN Multimedia

    Oeftiger, Adrian; Rumolo, Giovanni

    2016-01-01

    Hollow longitudinal phase space distributions have a flat profile and hence reduce the impact of transverse space charge. Dipolar parametric excitation with the phase loop feedback systems provides such hollow distributions under reproducible conditions. We present a procedure to create hollow bunches during the acceleration ramp of CERN’s PS Booster machine with minimal changes to the operational cycle. The improvements during the injection plateau of the downstream Proton Synchrotron are assessed in comparison to standard parabolic bunches.

  3. Longitudinal profile of channels cut by springs

    OpenAIRE

    Devauchelle , O.; PETROFF , A. P.; LOBKOVSKY , A. E.; Rothman , D. H.

    2011-01-01

    International audience; We propose a simple theory for the longitudinal profile of channels incised by groundwater flow. The aquifer surrounding the stream is represented in two dimensions through Darcy's law and the Dupuit approximation. The model is based on the assumption that, everywhere in the stream, the shear stress exerted on the sediment by the flow is close to the minimal intensity required to displace a sand grain. Because of the coupling of the stream discharge with the water tabl...

  4. Longitudinal Schottky noise of intense beam

    International Nuclear Information System (INIS)

    Pestrikov, D.V.

    1990-01-01

    Some phenomena, which can be observed in the longitudinal Schottky spectra in storage ring with electron cooling as well as some technical details, which can be useful for the models of fitting are reviewed. Results shows that both the spectra and the power of the Schottky noise of the coasting beam are very sensitive to collective behaviour of the beam. This can be used for fitting of Schottky noise measurements and recalculation of beam parameters, parameters of cooling device. 9 refs.; 4 figs

  5. Marginal longitudinal semiparametric regression via penalized splines

    KAUST Repository

    Al Kadiri, M.

    2010-08-01

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

  6. Marginal longitudinal semiparametric regression via penalized splines

    KAUST Repository

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

    2010-01-01

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

  7. Longitudinal ultrasonic waves dispersion in bars

    International Nuclear Information System (INIS)

    Suarez Antola, R.

    2001-01-01

    The exhibition intends to review some aspects of the propagation of the longitudinal ultrasonic pulses shortly in bars of traverse section uniform.Aspects they are part of the denominated geometric dispersion of the pulses.This phenomenon It can present like an additional complication in the ultrasonic essay of low frequency of thin pieces in structures and machines but takes place former ex professed in some applications of the wave guides been accustomed to in the prosecution of signs

  8. RADON reconstruction in longitudinal phase space

    International Nuclear Information System (INIS)

    Mane, V.; Peggs, S.; Wei, J.

    1997-01-01

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

  9. Substance use and motivation: a longitudinal perspective.

    Science.gov (United States)

    Korcha, Rachael A; Polcin, Douglas L; Bond, Jason C; Lapp, William M; Galloway, Gantt

    2011-01-01

    Motivation to change substance use behavior is an important component of the recovery process that has usually been studied at entry into treatment. Less studied, but equally important, is the measurement of motivation over time and the role motivation plays in subsequent substance use. The present study sought to examine longitudinal motivation toward sobriety among residents of sober living houses. Sober living residents (n = 167) were followed at 6-month intervals over an 18-month period and assessed for motivation and substance use outcomes at each study interview. Motivation was measured using the costs and benefits subscales of the Alcohol and Drug Consequences Questionnaire (ADCQ) and substance use outcomes included the Addiction Severity Index (ASI) alcohol scale, ASI drug scale, and peak density of substance use (number of days of most use in a month). Participants reported higher benefits than costs of sobriety or cutting down substance use at every study time point. Using lagged generalized estimating equation models, the ADCQ costs predicted increased severity for alcohol, drugs, and peak density, whereas the benefits subscale predicted decreased drug and peak density. Longitudinal measurement of motivation can be a useful clinical tool to understand later substance use problems. Given the mixed findings from prior studies on the effects of baseline motivation, a shift toward examining longitudinal measures of motivation at proximal and temporal intervals is indicated.

  10. Multilevel Cross-Dependent Binary Longitudinal Data

    KAUST Repository

    Serban, Nicoleta

    2013-10-16

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

  11. Operation of PEP longitudinal feedback system

    International Nuclear Information System (INIS)

    Allen, M.A.; Karvonen, L.G.; McConnell, R.A.; Schwarz, H.

    1981-03-01

    In order to suppress longitudinal coupled-bunch oscillations which might limit the capabilities of PEP, the 18 GeV e + e - storage ring at SLAC, a longitudinal feedback system is utilized. A frequency domain feedback system was chosen with the frequency spectrum of the stored beam being sampled close to a symmetry point in the ring where the feedback cavity itself is also located. The symmetry point chosen is symmetry point 5 which lies half-way between interaction regions 4 and 6. The system has been installed in PEP and is now operational. However, at stored currents up to the maximum stored in PEP to date at 14.5 GeV (approximately 40 mA in 6 bunches), the ring has been stable to all modes of longitudinal coupled-bunch oscillations both barycentric and the other fundamental modes. By deliberately detuning the main accelerating cavities, small multibunch oscillations can be introduced which, in turn, can be damped by the feedback system. Under optimized beam conditions the feedback system could be adjusted to positive feedback and excite oscillations with relatively small power to the feedback cavity. This will be described along with other details of the system

  12. Nucleon Spin Structure: Longitudinal and Transverse

    International Nuclear Information System (INIS)

    Chen, Jian-Ping

    2011-01-01

    Inclusive Deep-Inelastic Scattering (DIS) experiments have provided us with the most extensive information on the unpolarized and longitudinal polarized parton (quark and gluon) distributions in the nucleon. It has becoming clear that transverse spin and transverse momentum dependent distributions (TMDs) study are crucial for a more complete understanding of the nucleon structure and the dynamics of the strong interaction. The transverse spin structure and the TMDs are the subject of increasingly intense theoretical and experimental study recently. With a high luminosity electron beam facility, JLab has played a major role in the worldwide effort to study both the longitudinal and transverse spin structure. Highlights of recent results will be presented. With 12-GeV energy upgrade, JLab will provide the most precise measurements in the valence quark region to close a chapter in longitudinal spin study. JLab will also perform a multi-dimensional mapping of the transverse spin structure and TMDs in the valence quark region through Semi-Inclusive DIS (SIDIS) experiments, providing a 3-d partonic picture of the nucleon in momentum space and extracting the u and d quark tensor charges of the nucleon. The precision mapping of TMDs will also allow a detailed study of the quark orbital motion and its dynamics.

  13. Longitudinal analysis of mouse SDOCT volumes

    Science.gov (United States)

    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.

  14. [Longitudinal and specific analyses of physical performance in handball].

    Science.gov (United States)

    Schwesig, R; Fieseler, G; Jungermann, P; Noack, F; Irlenbusch, L; Leuchte, S; Fischer, D

    2012-09-01

    Sports-specific, biomechanical measuring stations and measuring-station trainings have become common practice in many forms of sports and are an essential element of the complex assessment of physical performance. In handball, however, there is still considerable research potential in this respect as well as in the systematic generation and acquisition of the requirements profile and progress of strain. The prime objective of the longitudinal study was to determine the potential performance and development of handball players (3 rd league) in general and in terms of handball sport in particular. Another objective was to establish correlations between tests and indicators of performance in competitions. 13 handball players (age: 26.5 ± 3.6 years) were tested three times (before and after the pre-season preparation phase and at the end of the first half of the season) on two test days each. The examination was composed of sprint test (ST, day 1), handball-specific complex test (HBKT, day 1) and assessment of treadmill diagnostics (LD, day 2). The surveyed parameters were lactate and heart rate (LD/HBKT) as well as time (ST, HBKT) and the number of errors (HBKT). The cardiac (Hfmax = 201 min-1) and metabolic strain (lactate = 17.8 mmol/L) in the HBKT were very high. In the preparatory phase, the average magnitudes of effect registered were at d = 0.31 (ST parameter), d = 0.68 (HBKT parameter) and d = 0.98 (LD parameter). The most significant improvements throughout the entire period of time were registered in the parameters v2 (LD; η2 = 0.371), total goal-throwing time (HBKT; η2 = 0.250), total penalty time (HBKT; η2 = 0.236) and total round 2 (HBKT; η2 = 0.227). In HBKT and LD, the performance level was stabilised by the end of the first half of the season. In terms of speed, however, there was a decline in performance abilities. The competition performance has its highest degree of correlation with cardial (defense: r = -0.656) and metabolic (offensive: r = -0

  15. Self-Efficacy as a Longitudinal Predictor of Perceived Cognitive Impairment in Individuals with Multiple Sclerosis

    Science.gov (United States)

    Hughes, Abbey J.; Beier, Meghan; Hartoonian, Narineh; Turner, Aaron P.; Amtmann, Dagmar; Ehde, Dawn M.

    2015-01-01

    Objective Self-efficacy plays an important role in symptom management and may be predictive of perceived cognitive impairment (PCI) for individuals with multiple sclerosis (MS). The primary aim of this study was to determine if self-efficacy longitudinally predicts two types of PCI in MS: general cognitive functioning and executive functioning. The secondary aim was to assess whether self-efficacy mediates the relationships between depression, fatigue, and PCI. Design Longitudinal analysis of self-report survey data collected over three years. Hierarchical regression analyses examined the relationship between self-efficacy and PCI, adjusting for depression and fatigue. Additional analyses tested self-efficacy as a mediator between depression, fatigue, and PCI. Setting Community-dwelling individuals with MS. Participants 233 individuals (age range 22-83 years) were recruited from a larger longitudinal survey study of 562 individuals with MS. Interventions Not applicable. Main Outcome Measures Primary outcome measures were the Applied Cognition General Concerns (ACGC) and Executive Function (ACEF) domains of the Quality of Life in Neurological Disorders (NeuroQoL) measures. Results Self-efficacy was significantly correlated with PCI at baseline (r = .40 to .53) and three years later (r = .36 to .44). In multivariate regression analyses, self-efficacy was a significant longitudinal predictor of PCI, both for general cognitive functioning (β = .20, p Self-efficacy partially mediated the relationships between depression, fatigue, and PCI. Conclusions Self-efficacy may influence how individuals with MS will perceive their cognitive functioning over time. Interventions that target self-efficacy, particularly early in the disease course, may lead to improvements in PCI, as well as improvements in fatigue and depression. PMID:25597915

  16. Measuring REU Success Through Longitudinal Tracking

    Science.gov (United States)

    Snow, M. A.; Wood, E. L.

    2015-12-01

    The Research Experience for Undergraduates (REU) site in solar and space physics in Boulder, Colorado is entering its 10th year. We use a variety of means to evaluate the performance of our program. Each year, we give the students a summative survey, and then we contact them three years later for a followup survey. We have achieved a high response rate in the followup survey, and the results are very encouraging. Students report that the REU program was helpful in determining their career goals, and the majority have gone on to graduate school or technical jobs. In this presentation, we will summarize the results of the survey data.

  17. A review of longitudinal community and hospital placements in medical education: BEME Guide No. 26.

    Science.gov (United States)

    Thistlethwaite, J E; Bartle, Emma; Chong, Amy Ai Ling; Dick, Marie-Louise; King, David; Mahoney, Sarah; Papinczak, Tracey; Tucker, George

    2013-08-01

    Traditionally, clinical learning for medical students consists of short-term and opportunistic encounters with primarily acute-care patients, supervised by an array of clinician preceptors. In response to educational concerns, some medical schools have developed longitudinal placements rather than short-term rotations. Many of these longitudinal placements are also integrated across the core clinical disciplines, are commonly termed longitudinal integrated clerkships (LICs) and often situated in rural locations. This review aimed to explore, analyse and synthesise evidence relating to the effectiveness of longitudinal placements, for medical students in particular to determine which aspects are most critical to successful outcomes. Extensive search of the literature resulted in 1679 papers and abstracts being considered, with 53 papers ultimately being included for review. The review group coded these 53 papers according to standard BEME review guidelines. Specific information extracted included: data relating to effectiveness, the location of the study, number of students involved, format, length and description of placement, the learning outcomes, research design, the impact level for evaluation and the main evaluation methods and findings. We applied a realist approach to consider what works well for whom and under what circumstances. The early LICs were all community-based immersion programs, situated in general practice and predominantly in rural settings. More recent LIC innovations were situated in tertiary-level specialist ambulatory care in urban settings. Not all placements were integrated across medical disciplines but were longitudinal in relation to location, patient base and/or supervision. Twenty-four papers focussed on one of four programs from different viewpoints. Most evaluations were student opinion (survey, interview, focus group) and/or student assessment results. Placements varied from one half day per week for six months through to full time

  18. Longitudinal study of perinatal maternal stress, depressive symptoms and anxiety.

    Science.gov (United States)

    Liou, Shwu-Ru; Wang, Panchalli; Cheng, Ching-Yu

    2014-06-01

    to understand the trends in, and relationships between, maternal stress, depressive symptoms and anxiety in pregnancy and post partum. a prospective longitudinal survey study was undertaken to explore maternal psychological distress throughout the perinatal period. The participants were recruited after 24 completed weeks of gestation, and were followed-up monthly until one month post partum (four surveys in total). participants were recruited from a single hospital in southern Taiwan, and asked to complete questionnaires in the hospital waiting area. inclusion criteria were: age ≥18 years, able to read and write Chinese, ≥24 weeks of gestation, singleton pregnancy and no pregnancy complications (including a diagnosis of antenatal depression or anxiety disorder). In total, 197 women completed all four surveys (response rate 74.62%). stress was measured with the 10-item Perceived Stress Scale, depressive symptoms were measured with the Center for Epidemiologic Studies' Depression scale, and anxiety was measured with the Zung Self-reported Anxiety Scale. Participants were followed-up at four time points: T1 (25-29 gestational weeks), T2 (30-34 gestational weeks), T3 (>34 gestational weeks) and T4 (4-6 weeks post partum). Appointments for data collection were made in accordance with the participants' antenatal and postnatal check-ups. The three types of maternal distress had different courses of change throughout the perinatal period, as levels of depressive symptoms remained unchanged, anxiety levels increased as gestation advanced but declined after birth, and stress decreased gradually during pregnancy but returned to the T1 level after birth. There was a low to high degree of correlation in maternal stress, depressive symptoms and anxiety in pregnancy and post partum. around one-quarter of the study participants had depressive symptoms during pregnancy and post partum. Stress and anxiety showed opposing courses during the perinatal period. Regardless of the

  19. Lesotho - Enterprise Survey

    Data.gov (United States)

    Millennium Challenge Corporation — The 2011 MCA-Lesotho baseline enterprise survey is a national survey of enterprises. The main objective of the survey was to assess the current status of businesses...

  20. 2015 Community Survey Data

    Data.gov (United States)

    Town of Chapel Hill, North Carolina — These are the answers to the 2015 Community Survey.A comprehensive summary of the survey results can be found here.The survey asked town members to address their...

  1. Findings from the Harvard Medical School Cambridge Integrated Clerkship, a Year-Long Longitudinal Psychiatry Experience.

    Science.gov (United States)

    Cheng, Elisa; Hirsh, David; Gaufberg, Elizabeth; Griswold, Todd; Wesley Boyd, J

    2018-06-01

    The Harvard Medical School Cambridge Integrated Clerkship is a longitudinal integrated clerkship that has provided an alternative clinical model for medical education in psychiatry since its inception in 2004. This study was undertaken in an effort to better understand the student experience of the Cambridge Integrated Clerkship and how it may have impacted students' perceptions of and interest in psychiatry, as well as performance. Qualitative surveys were sent via e-mail to the first 11 student cohorts who had completed the Cambridge Integrated Clerkship (from 2004 to 2014) and for whom we had e-mail addresses (N = 100), and the free-text responses were coded thematically. All available standardized scoring data and residency match data for Cambridge Integrated Clerkship graduates were obtained. From 2006 to 2014, 12 out of 73 Cambridge Integrated Clerkship students who entered the match chose a psychiatry residency (16.4%), four times more than students in traditional clerkships at Harvard Medical School (3.8% of 1355 students) or the national average (4.1% of 146,066 US applicants). Thirty of the 100 surveyed Cambridge Integrated Clerkship graduates (30%) responded to the qualitative survey with free-text remarks on a number of themes. Cambridge Integrated Clerkship students compared positively to their classmates in terms of standardized test performance. Their fourfold higher match rate into psychiatry compared to other students raises intriguing questions as to what role a longitudinal clerkship might have played in developing interest in psychiatry as a career.

  2. Rationales, design and recruitment for the Elfe longitudinal study

    Directory of Open Access Journals (Sweden)

    Salines Georges

    2009-09-01

    Full Text Available Abstract Background Many factors act simultaneously in childhood to influence health status, life chances and well being, including pre-birth influences, the environmental pollutants of early life, health status but also the social influences of family and school. A cohort study is needed to disentangle these influences and explore attribution. Methods Elfe will be a nationally representative cohort of 20 000 children followed from birth to adulthood using a multidisciplinary approach. The cohort will be based on the INSEE Permanent Demographic Panel (EDP established using census data and civil records. The sample size has been defined in order to match the representativeness criteria and to obtain some prevalence estimation, but also to address the research area of low exposure/rare effects. The cohort will be based on repeated surveys by face to face or phone interview (at birth and each year as well as medical interview (at 2 years and examination (at 6 years. Furthermore, biological samples will be taken at birth to evaluate the foetal exposition to toxic substances, environmental sensors will be placed in the child's homes. Pilot studies have been initiated in 2007 (500 children with an overall acceptance rate of 55% and are currently under progress, the 2-year survey being carried out in October this year. Discussion The longitudinal study will provide a unique source of data to analyse the development of children in their environment, to study the various factors interacting throughout the life course up to adulthood and to determine the impact of childhood experience on the individual's physical, psychological, social and professional development.

  3. Prepaid monetary incentives-Predictors of taking the money and completing the survey: Results from the International Tobacco Control (ITC) Four Country Survey.

    Science.gov (United States)

    Mutti, Seema; Kennedy, Ryan David; Thompson, Mary E; Fong, Geoffrey T

    2014-05-01

    Prepaid monetary incentives are used to address declining response rates in random-digit-dial surveys. There is concern among researchers that some respondents will accept the prepayment but not complete the survey. There is little research to understand check cashing and survey completing behaviors among respondents who receive pre-payment. Data from the International Tobacco Control Four Country Study-a longitudinal survey of smokers in Canada, the US, the UK, and Australia, were used to examine the impact of prepayment (in the form of checks, approximately $10USD) on sample profile. Approximately 14% of respondents cashed their check, but did not complete the survey, while about 14% did not cash their checks, but completed the survey. Younger adults (Canada, US), those of minority status (US), and those who had been in the survey for only two waves or less (Canada, US) were more likely to cash their checks and not complete the survey.

  4. Mild traumatic brain injury and fatigue: a prospective longitudinal study.

    Science.gov (United States)

    Norrie, Joan; Heitger, Marcus; Leathem, Janet; Anderson, Tim; Jones, Richard; Flett, Ross

    2010-01-01

    To examine fatigue prevalence, severity, predictors and co-variates over 6 months post-mild traumatic brain injury (MTBI). Longitudinal prospective study including 263 adults with MTBI. Participants completed the Fatigue Severity Scale (FSS), Rivermead Post-concussion Symptoms Questionnaire (RPSQ), Hospital Anxiety and Depression Scale (HADS) and the Short Form 36 Health Survey-Version 2 (SF-36v2). Complete data were available for 159 participants. Key measures; prevalence--RPSQ Item 6: severity--FSS. The effect of time on fatigue prevalence and severity was examined using ANOVA. Multiple regression analysis identified statistically significant covariates. Post-MTBI fatigue prevalence was 68%, 38% and 34% at 1 week, 3 and 6 months, respectively. There was a strong effect for time over the first 3 months and moderate-to-high correlations between fatigue prevalence and severity. Early fatigue strongly predicted later fatigue; depression, but not anxiety was a predictor. Fatigue was seen as laziness by family or friends in 30% of cases. Post-MTBI fatigue is a persistent post-concussion symptom, exacerbated by depression but not anxiety. It diminishes in the first 3 months and then becomes relatively stable, suggesting the optimum intervention placement is at 3 months or more post-MTBI.

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

    Science.gov (United States)

    Pedersen, Willy

    2014-01-01

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

  6. Factors controlling floc settling velocity along a longitudinal estuarine transect

    Science.gov (United States)

    Manning, A.J.; Schoellhamer, D.H.

    2013-01-01

    A 147 km longitudinal transect of flocculated cohesive sediment properties in San Francisco Bay (SFB) was conducted on June 17th, 2008. Our aim was to determine the factors that control floc settling velocity along the longitudinal axis of the estuary. The INSSEV-LF video system was used to measure floc diameters and settling velocities at 30 stations at a distance of 0.7 m above the estuary bed. Floc sizes (D) ranged from 22 μm to 639 μm and settling velocities (Ws) ranged between 0.04 mm·s− 1 and 15.8 mm·s− 1 during the longitudinal transect. Nearbed turbulent shear stresses throughout the transect duration were within the 0.2–0.5 Pa range which typically stimulates flocculation growth. The individual D–Ws–floc density plots suggest the suspended sediments encountered throughout SFB were composed of both muddy cohesive sediment and mixed sediments flocs. Mass-weighted population mean settling velocity (Wsmass) ranged from 0.5 mm·s− 1 to 10 mm·s− 1. The macrofloc and microfloc (demarcation at 160 μm) sub-populations demonstrated parameterised settling velocities which spanned nearly double the range of the sample mean settling velocities (Wsmean). The macroflocs tended to dominate the suspended mass (up to 77% of the ambient suspended solid concentration; SSC) from San Pablo Bay to Carquinez Strait (the vicinity of the turbidity maximum zone). Microfloc mass was particularly significant (typically 60–100% of the SSC) in the northern section of South Bay and most of Central Bay. The transect took eleven hours to complete and was not fully synoptic. During slack tide, larger and faster settling flocs deposited, accounting for most of the longitudinal variability. The best single predictor of settling velocity was water velocity 39 min prior to sampling, not suspended-sediment concentration or salinity. Resuspension and settling lags are likely responsible for the lagged response of settling velocity to water velocity. The distribution of

  7. Longitudinal Associations Between Formal Volunteering and Cognitive Functioning.

    Science.gov (United States)

    Proulx, Christine M; Curl, Angela L; Ermer, Ashley E

    2018-03-02

    The present study examines the association between formal volunteering and cognitive functioning over time. We also examine the moderating roles of race, sex, education, and time. Using 11,100 participants aged 51 years and older and nine waves of data from the Health and Retirement Survey, we simultaneously modeled the longitudinal associations between engaging in formal volunteering and changes in cognitive functioning using multilevel models. Formal volunteering was associated with higher levels of cognitive functioning over time, especially with aspects of cognitive functioning related to working memory and processing. This association was stronger for women than it was for men, and for those with below average levels of education. The positive association between formal volunteering and cognitive functioning weakened over time when cognitive functioning was conceptualized as memory, but strengthened over time when conceptualized as working memory and processing. Volunteering is a productive activity that is beneficial not just to society, but to volunteers' levels of cognitive functioning in older age. For women and those with lower levels of education, formal volunteering appears particularly beneficial to working memory and processing. © 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. A longitudinal study of language learners’ images about Russia

    Directory of Open Access Journals (Sweden)

    Nikitina Larisa

    2016-05-01

    Full Text Available Several studies in the field of applied linguistics have explored images held by language learners about a target language country. However, for the most part, these studies focused on learners of modern European languages, such as German, Spanish and French and they were conducted in Western educational contexts. Besides, none of the previous investigations attempted to conduct a systematic classification of the language learners’ images. The present longitudinal study addressed these gaps in the research literature. It explored images about Russia held by Malaysian learners of the Russian language in a large university in East Malaysia. This article reports the findings of three questionnaire surveys conducted in 2004, 2007 and 2010. It was found that the images about Russia held by the participants were diverse and clustered around eight countryrelated aspects. Content of some categories of images was stable and changed little over time. Other categories were more fluid and more prone to change. The paper concludes with a discussion of pedagogical implications that can be derived from the findings.

  9. Whole grain intake: The Baltimore Longitudinal Study of Aging.

    Science.gov (United States)

    Maras, Janice E; Newby, P K; Bakun, Peter J; Ferrucci, Luigi; Tucker, Katherine L

    2009-02-01

    Our objective was to identify major dietary sources of whole grains and to describe the construction of a database of whole grain content of foods. Dietary information was collected with 7-d food records from men and women in the Baltimore Longitudinal Study of Aging, mean age 62.1 +/- 16.0 years, who participated in the dietary assessment portion of the study (n = 1516), and estimates of whole grain intake were obtained from a newly developed database. The Pyramid Servings database and 1994-1996 Continuing Survey of Food Intakes by Individuals (CSFII) recipe ingredients database were then used to calculate both servings and gram weights of whole grain intakes. Mean intakes of whole grains, refined grains, and total grains, as well as frequency of intake for major whole grain food groups and whole grain content for each group, were calculated. Top contributors of whole grains were ready-to-eat breakfast cereals (made with whole grain as well as bran), hot breakfast cereals (made with whole grain), multi-grain bread, and whole wheat bread. While more research is needed to better understand the benefits of whole grains, the development of research tools, including databases to accurately assess whole grain intake, is a critical step in completing such research.

  10. Longitudinal study on osteoarthritis and bone metabolism

    Directory of Open Access Journals (Sweden)

    L. Postiglione

    2011-09-01

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

  11. Longitudinal Patterns of Electronic Teen Dating Violence Among Middle School Students.

    Science.gov (United States)

    Cutbush, Stacey; Williams, Jason; Miller, Shari; Gibbs, Deborah; Clinton-Sherrod, Monique

    2018-03-01

    We investigated rates and developmental trends of electronic teen dating violence (TDV) perpetration and victimization overall and by gender. Data were collected from a single cohort of seventh-grade students from four schools using paper-and-pencil surveys administered at 6-month intervals ( N = 795). Data were analyzed with descriptive statistics and longitudinal growth models to estimate change over time in TDV. Overall, 32% of youth reported electronic TDV perpetration, and 51% reported electronic TDV victimization. Victimization was more prevalent for boys (42%) than for girls (31%) at baseline only ( t = 2.55, p prevention interventions.

  12. Resonant longitudinal Zitterbewegung in zigzag graphene nanoribbons

    KAUST Repository

    Ghosh, S.; Schwingenschlö gl, Udo; Manchon, Aurelien

    2015-01-01

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

  13. Longitudinal wave ultrasonic inspection of austenitic weldments

    International Nuclear Information System (INIS)

    Gray, B.S.; Hudgell, R.J.; Seed, H.

    1980-01-01

    Successful volumetric inspection of LMFBR primary circuits, and also much of the secondary circuit, is dependent on the availability of satisfactory examination procedures for austenitic welds. Application of conventional ultrasonic techniques is hampered by the anisotropic, textured structure of the weld metal and this paper describes development work on the use of longitudinal wave techniques. In addition to confirming the dominant effects of the weld structure on ultrasound propagation some results are given of studies utilising deliberately induced defects in Manual Metal Arc Welds in 50 mm plate together with preliminary work on the inspection of narrow austenitic welds fabricated by automatic processes. (author)

  14. Resonant longitudinal Zitterbewegung in zigzag graphene nanoribbons

    KAUST Repository

    Ghosh, S.

    2015-01-08

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

  15. Regional vulnerability of longitudinal cortical association connectivity

    Directory of Open Access Journals (Sweden)

    Rafael Ceschin

    2015-01-01

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

  16. Longitudinal emittance measurement at the ATS

    International Nuclear Information System (INIS)

    Cottingame, W.B.; Cortez, J.H.; Higgins, W.W.; Sander, O.R.; Sandoval, D.P.

    1986-01-01

    With increasing brightness, beam diagnostic techniques requiring interception of the beam become impractical. For H - particle beams, solutions for this problem based on the phenomenon of photodissociation are now being investigated at the Los Alamos National Laboratory accelerator test stand (ATS). A laser can be used to selectively neutralize portions of the beam than can be characterized after the charged particles have been swept away. We have used this technique for measuring longitudinal emittance at the output of the ATS radio-frequency quadrupole

  17. Longitudinal Diagnostics for Short Electron Beam Bunches

    Energy Technology Data Exchange (ETDEWEB)

    Loos, H.; /SLAC

    2010-06-11

    Single-pass free electron lasers require high peak currents from ultra-short electron bunches to reach saturation and an accurate measurement of bunch length and longitudinal bunch profile is necessary to control the bunch compression process from low to high beam energy. The various state-of-the-art diagnostics methods from ps to fs time scales using coherent radiation detection, RF deflection, and other techniques are presented. The use of linear accelerators as drivers for free electron lasers (FEL) and the advent of single-pass (SASE) FELs has driven the development of a wide range of diagnostic techniques for measuring the length and longitudinal distribution of short and ultra-short electron bunches. For SASE FELs the radiation power and the length of the undulator needed to achieve saturation depend strongly on the charge density of the electron beam. In the case of X-ray FELs, this requires the accelerator to produce ultra-high brightness beams with micron size transverse normalized emittances and peak currents of several kA through several stages of magnetic bunch compression. Different longitudinal diagnostics are employed to measure the peak current and bunch profile along these stages. The measurement techniques can be distinguished into different classes. Coherent methods detect the light emitted from the beam by some coherent radiation process (spectroscopic measurement), or directly measure the Coulomb field traveling with the beam (electro-optic). Phase space manipulation techniques map the time coordinate onto a transverse dimension and then use conventional transverse beam diagnostics (transverse deflector, rf zero-phasing). Further methods measure the profile or duration of an incoherent light pulse emitted by the bunch at wavelengths much shorted than the bunch length (streak camera, fluctuation technique) or modulate the electron beam at an optical wavelength and then generate a narrow bandwidth radiation pulse with the longitudinal profile of

  18. Inclusive charge longitudinal response in finite nuclei

    International Nuclear Information System (INIS)

    Alberico, W.M.; Molinari, A.; Czerski, P.; Czerski, P.; Ericson, M.

    1986-03-01

    The experimental dynamic and static longitudinal structure factors of 12 C, 40 Ca and 56 Fe are investigated with a semiclassical RPA theory. The parameters entering into the nuclear mean field (including the nucleon effective mass) and in the isoscalar and isovector particle-hole forces are set by best fitting procedures. Quite reasonable values of these quantities allow a satisfactory account of the experimental data over a wide range of momentum transfers in all the three nuclei. However, to achieve this result, the proton root mean square radius has to be increased over the conventional value of about 13% in 12 C and 22% in 40 Ca and 56 Fe

  19. Longitudinal vortices in a transitioning boundary layer

    International Nuclear Information System (INIS)

    Anders, J.B.; Backwelder, R.F.

    1980-01-01

    Naturally occurring spanwise variations of the streamwise velocity component, characteristic of longitudinal vortices embedded in a transitioning boundary layer were explored using hot-wire anemometers. A vibrating ribbon introduced stable or unstable Tollmien-Schlichting waves into the laminar boundary layer. These damped or growing disturbances always developed a strong three-dimensional pattern even though no spanwise perturbations were artificially induced. Changing the radius of the leading edge and other modifications to the flat plate, wind tunnel and boundary layer did not alter the spanwise wavelength of the vortices. (orig.)

  20. Prevalence and correlates of unhealthy weight control behaviors: findings from the national longitudinal study of adolescent health

    OpenAIRE

    Stephen, Eric M; Rose, Jennifer S; Kenney, Lindsay; Rosselli-Navarra, Francine; Weissman, Ruth Striegel

    2014-01-01

    Background A recent study examined the prevalence, clinical correlates, age trends, and stability of unhealthy weight control behaviors (UWCB; purging and diet pill use) in a nationally representative sample of Norwegian boys and girls. The purpose of this study was to provide similar, comparative analyses for a nationally representative sample of American youth. Methods Data were extracted from the restricted use data files of survey Waves I, II, and III of the National Longitudinal Study of...

  1. Digital Divides and Socio-Demographic Factors: A Longitudinal Quantitative Study of Internet Users in U.S. from 2000 to 2010

    Science.gov (United States)

    Zhang, Peter H.

    2013-01-01

    This research attempted to reveal the existence of digital divides, their relationships to users' socio-demographics, and the Internet adoption and usage patterns. It was a longitudinal investigation targeted to the adults eighteen years or older in the household setting from the nation-wide surveys conducted in the United States between 2000…

  2. Online conversation and corporate reputation: A two-wave longitudinal study on the effects of social media exposure to a highly interactive company.

    NARCIS (Netherlands)

    Dijkmans, C.; Kerkhof, P.; Buyukcan-Tetik, A.; Beukeboom, C.J.

    2015-01-01

    In this paper, we investigate whether and to what extent exposure to a company's social media activities over time is beneficial for corporate reputation, and whether conversational human voice mediates this relation. In a two-wave longitudinal survey among 1969 respondents, we assessed consumers'

  3. A Longitudinal Examination of the Bidirectional Associations among Perceived Parenting Behaviors, Adolescent Disclosure and Problem Behavior across the High School Years

    Science.gov (United States)

    Willoughby, Teena; Hamza, Chloe A.

    2011-01-01

    This longitudinal study investigated the importance of parental monitoring to the deterrence of adolescent problem behavior by examining bidirectional associations among perceived parental monitoring, adolescent disclosure and problem behaviors across the high school years. Adolescents (N = 2,941; 50.3% female) were surveyed each year from grades…

  4. Digital Game Violence and Direct Aggression in Adolescence: A Longitudinal Study of the Roles of Sex, Age, and Parent-Child Communication

    Science.gov (United States)

    Wallenius, Marjut; Punamaki, Raija-Leena

    2008-01-01

    This study investigated the roles of sex, age, and parent-child communication in moderating the association between digital game violence and direct aggression in a two-year longitudinal study. Finnish 12- and 15-year-old adolescents (N = 316) participated in the follow-up survey. As hypothesized, digital game violence was linked to direct…

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

    Science.gov (United States)

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

    2014-01-01

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

  6. Does the Universal Health Insurance Program Affect Urban-Rural Differences in Health Service Utilization among the Elderly? Evidence from a Longitudinal Study in Taiwan

    Science.gov (United States)

    Liao, Pei-An; Chang, Hung-Hao; Yang, Fang-An

    2012-01-01

    Purpose: To assess the impact of the introduction of Taiwan's National Health Insurance (NHI) on urban-rural inequality in health service utilization among the elderly. Methods: A longitudinal data set of 1,504 individuals aged 65 and older was constructed from the Survey of Health and Living Status of the Elderly. A difference-in-differences…

  7. Longitudinal dynamics of laser-cooled fast ion beams

    DEFF Research Database (Denmark)

    Weidemüller, M.; Eike, B.; Eisenbarth, U.

    1999-01-01

    We present recent results of our experiments on laser cooling of fast stored ion beams at the Heidelberg Test Storage Ring. The longitudinal motion of the ions is directly cooled by the light pressure force, whereas efficient transverse cooling is obtained indirectly by longitudinal-transverse co......We present recent results of our experiments on laser cooling of fast stored ion beams at the Heidelberg Test Storage Ring. The longitudinal motion of the ions is directly cooled by the light pressure force, whereas efficient transverse cooling is obtained indirectly by longitudinal....... When applying laser cooling in square-well buckets over long time intervals, hard Coulomb collisions suddenly disappear and the longitudinal temperature drops by about a factor of three. The observed longitudinal behaviour of the beam shows strong resemblance with the transition to an Coulomb...

  8. Longitudinal Muscle Dysfunction in Achalasia Esophagus and Its Relevance

    OpenAIRE

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

    2013-01-01

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

  9. Longitudinal data analysis a handbook of modern statistical methods

    CERN Document Server

    Fitzmaurice, Garrett; Verbeke, Geert; Molenberghs, Geert

    2008-01-01

    Although many books currently available describe statistical models and methods for analyzing longitudinal data, they do not highlight connections between various research threads in the statistical literature. Responding to this void, Longitudinal Data Analysis provides a clear, comprehensive, and unified overview of state-of-the-art theory and applications. It also focuses on the assorted challenges that arise in analyzing longitudinal data. After discussing historical aspects, leading researchers explore four broad themes: parametric modeling, nonparametric and semiparametric methods, joint

  10. Longitudinal Phase Space Tomography with Space Charge

    CERN Document Server

    Hancock, S; Lindroos, M

    2000-01-01

    Tomography is now a very broad topic with a wealth of algorithms for the reconstruction of both qualitative and quantitative images. In an extension in the domain of particle accelerators, one of the simplest algorithms has been modified to take into account the non-linearity of large-amplitude synchrotron motion. This permits the accurate reconstruction of longitudinal phase space density from one-dimensional bunch profile data. The method is a hybrid one which incorporates particle tracking. Hitherto, a very simple tracking algorithm has been employed because only a brief span of measured profile data is required to build a snapshot of phase space. This is one of the strengths of the method, as tracking for relatively few turns relaxes the precision to which input machine parameters need to be known. The recent addition of longitudinal space charge considerations as an optional refinement of the code is described. Simplicity suggested an approach based on the derivative of bunch shape with the properties of...

  11. Tomographic Measurements of Longitudinal Phase Space Density

    CERN Document Server

    Hancock, S; McIntosh, E; Metcalf, M

    1999-01-01

    Tomography : the reconstruction of a two-dimensional image from a series of its one-dimensional projections is now a very broad topic with a wealth of algorithms for the reconstruction of both qualitative and quantitative images. One of the simplest algorithms has been modified to take into account the non-linearity of large-amplitude synchrotron motion in a particle accelerator. This permits the accurate reconstruction of longitudinal phase space density from one-dimensional bunch profile data. The algorithm was developed in Mathematica TM in order to exploit the extensive built-in functions and graphics. Subsequently, it has been recoded in Fortran 90 with the aim of reducing the execution time by at least a factor of one hundred. The choice of Fortran 90 was governed by the desire ultimately to exploit parallel architectures, but sequential compilation and execution have already largely yielded the required gain in speed. The use of the method to produce longitudinal phase space plots, animated sequences o...

  12. A longitudinal study of urea cycle disorders.

    Science.gov (United States)

    Batshaw, Mark L; Tuchman, Mendel; Summar, Marshall; Seminara, Jennifer

    2014-01-01

    The Urea Cycle Disorders Consortium (UCDC) is a member of the NIH funded Rare Diseases Clinical Research Network and is performing a longitudinal study of 8 urea cycle disorders (UCDs) with initial enrollment beginning in 2006. The consortium consists of 14 sites in the U.S., Canada and Europe. This report summarizes data mining studies of 614 patients with UCDs enrolled in the UCDC's longitudinal study protocol. The most common disorder is ornithine transcarbamylase deficiency, accounting for more than half of the participants. We calculated the overall prevalence of urea cycle disorders to be 1/35,000, with 2/3rds presenting initial symptoms after the newborn period. We found the mortality rate to be 24% in neonatal onset cases and 11% in late onset cases. The most common precipitant of clinical hyperammonemic episodes in the post-neonatal period was intercurrent infections. Elevations in both blood ammonia and glutamine appeared to be biomarkers for neurocognitive outcome. In terms of chronic treatment, low protein diet appeared to result in normal weight but decreased linear growth while N-scavenger therapy with phenylbutyrate resulted in low levels of branched chain amino acids. Finally, we found an unexpectedly high risk for hepatic dysfunction in patients with ornithine transcarbamylase deficiency. This natural history study illustrates how a collaborative study of a rare genetic disorder can result in an improved understanding of morbidity and disease outcome. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Parental mediation and cyberbullying - a longitudinal study.

    Science.gov (United States)

    Chng, Grace S; Liau, Albert; Khoo, Angeline; Li, Dongdong

    2014-01-01

    Parents use active and restrictive mediation strategies to guide and regulate children's online participation and the online risks they encounter. However, changes in parental mediation do occur over time and the effectiveness of these strategies on cyberbullying demands for further empirical investigation. The current study addresses these issues with a sample of 1084 students (49% girls) in a longitudinal, three-wave design. Gender differences were tested via multi-group analyses. Longitudinal growth models showed that parental use of both active and restrictive mediation decreased over time. For both types of mediation, the mean rate of change had a significant effect on boys' engagement in cyberbullying, but not for girls. Initial levels of restrictive mediation, but not active mediation, were found to be significantly predictive of cyberbullying in both genders. Girls had higher initial levels of both parental mediation types in comparison to boys. The results reveal that the effectiveness of active and restrictive mediation in relation to students' cyberbullying differs and informs us on gender differences. The implications of these results for parental education in online mediation are discussed.

  14. Longitudinal density monitor for the LHC

    Science.gov (United States)

    Jeff, A.; Andersen, M.; Boccardi, A.; Bozyigit, S.; Bravin, E.; Lefevre, T.; Rabiller, A.; Roncarolo, F.; Welsch, C. P.; Fisher, A. S.

    2012-03-01

    The longitudinal density monitor (LDM) is primarily intended for the measurement of the particle population in nominally empty rf buckets. These so-called satellite or ghost bunches can cause problems for machine protection as well as influencing the luminosity calibration of the LHC. The high dynamic range of the system allows measurement of ghost bunches with as little as 0.01% of the main bunch population at the same time as characterization of the main bunches. The LDM is a single-photon counting system using visible synchrotron light. The photon detector is a silicon avalanche photodiode operated in Geiger mode, which allows the longitudinal distribution of the LHC beams to be measured with a resolution of 90 ps. Results from the LDM are presented, including a proposed method for constructing a 3-dimensional beam density map by scanning the LDM sensor in the transverse plane. In addition, we present a scheme to improve the sensitivity of the system by using an optical switching technique.

  15. Longitudinal density monitor for the LHC

    Directory of Open Access Journals (Sweden)

    A. Jeff

    2012-03-01

    Full Text Available The longitudinal density monitor (LDM is primarily intended for the measurement of the particle population in nominally empty rf buckets. These so-called satellite or ghost bunches can cause problems for machine protection as well as influencing the luminosity calibration of the LHC. The high dynamic range of the system allows measurement of ghost bunches with as little as 0.01% of the main bunch population at the same time as characterization of the main bunches. The LDM is a single-photon counting system using visible synchrotron light. The photon detector is a silicon avalanche photodiode operated in Geiger mode, which allows the longitudinal distribution of the LHC beams to be measured with a resolution of 90 ps. Results from the LDM are presented, including a proposed method for constructing a 3-dimensional beam density map by scanning the LDM sensor in the transverse plane. In addition, we present a scheme to improve the sensitivity of the system by using an optical switching technique.

  16. Splinting of Longitudinal Fracture: An Innovative Approach

    Directory of Open Access Journals (Sweden)

    Rashmi Bansal

    2016-01-01

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

  17. Using Electronic Surveys: Advice from Survey Professionals.

    Directory of Open Access Journals (Sweden)

    David M. Shannon

    2002-01-01

    Full Text Available The study reports the perceptions and recommendations of sixty-two experienced survey..researchers from the American Educational Research Association regarding the use of..electronic surveys. The most positive aspects cited for the use of electronic surveys were..reduction of costs (i.e., postage, phone charges, the use of electronic mail for pre-notification or..follow-up purposes, and the compatibility of data with existing software programs. These..professionals expressed limitations in using electronic surveys pertaining to the limited..sampling frame as well as issues of confidentiality, privacy, and the credibility of the sample...They advised that electronic surveys designed with the varied technological background and..capabilities of the respondent in mind, follow sound principles of survey construction, and be..administered to pre-notified, targeted populations with published email addresses.

  18. Pediatrics Residents' Confidence and Performance Following a Longitudinal Quality Improvement Curriculum.

    Science.gov (United States)

    Courtlandt, Cheryl; Noonan, Laura; Koricke, Maureen Walsh; Zeskind, Philip Sanford; Mabus, Sarah; Feld, Leonard

    2016-02-01

    Quality improvement (QI) training is an integral part of residents' education. Understanding the educational value of a QI curriculum facilitates understanding of its impact. The purpose of this study was to evaluate the effects of a longitudinal QI curriculum on pediatrics residents' confidence and competence in the acquisition and application of QI knowledge and skills. Three successive cohorts of pediatrics residents (N = 36) participated in a longitudinal curriculum designed to increase resident confidence in QI knowledge and skills. Key components were a succession of progressive experiential projects, QI coaching, and resident team membership culminating in leadership of the project. Residents completed precurricular and postcurricular surveys and demonstrated QI competence by performance on the pediatric QI assessment scenario. Residents participating in the Center for Advancing Pediatric Excellence QI curriculum showed significant increases in pre-post measures of confidence in QI knowledge and skills. Coaching and team leadership were ranked by resident participants as having the most educational value among curriculum components. A pediatric QI assessment scenario, which correlated with resident-perceived confidence in acquisition of QI skills but not QI knowledge, is a tool available to test pediatrics residents' QI knowledge. A 3-year longitudinal, multimodal, experiential QI curriculum increased pediatrics residents' confidence in QI knowledge and skills, was feasible with faculty support, and was well-accepted by residents.

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

    Science.gov (United States)

    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.

  20. The concurrent and longitudinal effects of child disability types and health on family experiences.

    Science.gov (United States)

    Wei, Xin; Yu, Jennifer W

    2012-01-01

    This study examines the concurrent and longitudinal effects of children's disability types and health on family experiences, namely, parent divorce, mother's unemployment, and receipt of social welfare. The parent and school staff survey data for 1999 and 2004 from the Special Education Elementary Longitudinal Study were analyzed, when the ages of children with disabilities ranged from 6 to 17. Weighted logistic regressions using Taylor Series Linearization were used to model the concurrent associations and longitudinal association between children's disability types and health and family experiences. Models were adjusted to account for other children in the family with disabilities, sociodemographic characteristics, and other family experiences variables. Family experiences varied significantly by disability type in 1999. Compared with families of children with learning disabilities, parents of children with emotional disturbances were 81% more likely to get divorced, and 2.5 times more likely to receive welfare from 1999 to 2004. Mothers of children with a secondary disability were 81% more likely to be unemployed than those of children without a secondary disability. These findings indicate that specific disability types in children have an influence on family experience, and that some of those influences may persist over time. Families of children with emotional disturbances appear to be particularly at risk for negative family experiences. Clinicians, educators, and policymakers should be aware of the complex needs of families of children with disabilities when considering the types of services and supports provided to both children with disabilities and their families.

  1. Posterior longitudinal ligament status in cervical spine bilateral facet dislocations

    International Nuclear Information System (INIS)

    Carrino, John A.; Manton, Geoffrey L.; Morrison, William B.; Flanders, Adam E.; Vaccaro, Alex R.; Schweitzer, Mark E.

    2006-01-01

    It is generally accepted that cervical spine bilateral facet dislocation results in complete disruption of the posterior longitudinal ligament. The goal of this study was to evaluate the integrity of numerous spine-stabilizing structures by MRI, and to determine if any associations between injury patterns exist with respect to the posterior longitudinal ligament status. Retrospective case series. A retrospective review was performed of 30 cervical spine injury subjects with bilateral facet dislocation. Assessment of 1.5T MRI images was carried out for: intervertebral disc disruption, facet fracture, and ligamentous disruption. Statistical analyses were performed to evaluate for associations between various injury patterns and posterior longitudinal ligament status. The frequency of MRI abnormalities was: anterior longitudinal ligament disruption (26.7%), disc herniation or disruption (90%), posterior longitudinal ligament disruption (40%), facet fracture (63.3%) and disruption of the posterior column ligament complex (97%). There were no significant associations between injury to the posterior longitudinal ligament and other structures. Compared to surgical reports, MRI was accurate for determining the status for 24 of 26 ligaments (three of three anterior longitudinal ligament, seven of nine posterior longitudinal ligament, and 14 of 14 posterior column ligament complex) but generated false negatives in two instances (in both MRI showed an intact posterior longitudinal ligament that was torn at surgery). (orig.)

  2. Theory of superconducting magnet suspension: main results survey

    International Nuclear Information System (INIS)

    Voevodskii, K.E.; Kochetkov, V.M.

    1981-01-01

    A survey is given of theoretical achievements on electro-dynamic suspension of high speed ground vehicles with superconducting magnets. The problems discussed, are calculation of lift and drag forces acting on a superconducting magnet, the latter moving above a guideway structure which may be of two different types (either conducting sheet or a series of discrete loops); influence of irregularities of the guideway structure; vertical and longitudinal stability of suspension. (author)

  3. A longitudinal comparison of the growth factors of Slovenian fast growing enterprises

    Directory of Open Access Journals (Sweden)

    Viljem Pšeničny

    2009-11-01

    Full Text Available The article presents the main features of Slovenia’s fastest growing companies and compares them with “gazelles” in the EU. The longitudinal survey presented connects with three other studies applying the same research method, namely studies employing the same questionnaire on growth factors that affect growing companies through to the criteria by which they were selected as growing businesses for the survey. The author notes that the growth factors which have an impact on Slovenian businesses and gazelles in the EU mostly do not show any significant differences, and that these differences also did not change significantly over a 15-year period. This hypothesis is verified by both statistical methods and the data mining method called machine learning from examples.

  4. A Health 'Kuznets' Curve'? Cross-Sectional and Longitudinal Evidence on Concentration Indices'.

    Science.gov (United States)

    Costa-Font, Joan; Hernandez-Quevedo, Cristina; Sato, Azusa

    2018-01-01

    The distribution of income related health inequalities appears to exhibit changing patterns when both developing countries and developed countries are examined. This paper tests for the existence of a health Kuznets' curve; that is, an inverse U-shape pattern between economic developments (as measured by GDP per capita) and income-related health inequalities (as measured by concentration indices). We draw upon both cross sectional (the World Health Survey) and a long longitudinal (the European Community Household Panel survey) dataset. Our results suggest evidence of a health Kuznets' curve on per capita income. We find a polynomial association where inequalities decline when GDP per capita reaches a magnitude ranging between $26,000 and $38,700. That is, income-related health inequalities rise with GDP per capita, but tail off once a threshold level of economic development has been attained.

  5. Longitudinal muscle dysfunction in achalasia esophagus and its relevance.

    Science.gov (United States)

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

    2013-04-01

    Muscularis propria of the esophagus is organized into circular and longitudinal muscle layers. Goal of this review is to summarize the role of longitudinal muscle in physiology and pathophysiology of esophageal sensory and motor function. Simultaneous manometry and ultrasound imaging that measure circular and longitudinal muscle contraction respectively reveal that during peristalsis 2 layers of the esophagus contract in perfect synchrony. On the other hand, during transient relaxation of the lower esophageal sphincter (LES), longitudinal muscle contracts independently of circular muscle. Recent studies provide novel insights, i.e., longitudinal muscle contraction of the esophagus induces LES relaxation and possibly descending relaxation of the esophagus. In achalasia esophagus and other motility disorders there is discoordination between the 2 muscle layers. Longitudinal muscle contraction patterns are different in the recently described three types of achalasia identified by high-resolution manometry. Robust contraction of the longitudinal muscle in type II achalasia causes pan-esophageal pressurization and is the mechanism of whatever little esophageal emptying that take place in the absence of peristalsis and impaired LES relaxation. It may be that preserved longitudinal muscle contraction is also the reason for superior outcome to medical/surgical therapy in type II achalasia esophagus. Prolonged contractions of longitudinal muscles of the esophagus is a possible mechanism of heartburn and "angina like" pain seen in esophageal motility disorders and possibly achalasia esophagus. Novel techniques to record longitudinal muscle contraction are on the horizon. Neuro-pharmacologic control of circular and longitudinal muscles is different, which provides an important opportunity for the development of novel pharmacological therapies to treat sensory and motor disorders of the esophagus.

  6. Longitudinal study of prognostic factors in established periodontitis patients.

    Science.gov (United States)

    Machtei, E E; Dunford, R; Hausmann, E; Grossi, S G; Powell, J; Cummins, D; Zambon, J J; Genco, R J

    1997-02-01

    Numerous indicators for disease progression have been described in the last decade. The purpose of this study was to examine, longitudinally, a large battery of clinical, microbiological, and immunological indicators, to try to determine whether the presence of one or a combination of these parameters at baseline, would correlate positively with increased attachment and or bone loss (true prognostic factors). Following initial screening, 79 patients with established periodontitis were monitored longitudinally for one year. Whole mouth clinical measurements, plaque gingival and calculus indices, together with pocket depth and attachment level measurements, were repeated every three months. Full mouth radiographic survey, performed at baseline and 12 months, served to determine changes in crestal bone height using an image enhancement technique. Subgingival plaque samples were taken at baseline and every 3 months. Immunofluorescence assays were performed for the a battery of target microorganisms. Serum and GCF samples for IgG subclasses analysis were obtained at each visit and assayed using ELISA techniques. Likewise blood, samples were also drawn at each visit for a quantitative analysis of serum cotinine level. The overall mean attachment loss (AL) and bone loss (BL) were almost identical (0.159 mm and 0.164 mm, respectively). Individual patients variation was large (-0.733 to +1.004 mm). An overall 6.89% of sites were active; individual patients' means ranged from 0-28.9%. Mean pocket depth (PD) showed minimal change over the study period (-0.033 mm) thus suggesting that most if not all the AL was accompained by concomitant gingival recession. Smokers exhibited greater AL and radiographic BL compared to non-smokers. Likewise, patients' cotinine level showed direct correlation with outcomes of progressive periodontal breakdown. Past severity of periodontal involvement, as reflected in the patients baseline PD, AL and crestal bone height, showed good correlation

  7. The environmental survey manual

    International Nuclear Information System (INIS)

    1987-08-01

    The purpose of this manual is to provide guidance to the Survey and Sampling and Analysis teams that conduct the one-time Environmental Survey of the major US Department of Energy (DOE) operating facilities. This manual includes a discussion of DOE's policy on environmental issues, a review of statutory guidance as it applies to the Survey, the procedures and protocols to be used by the Survey teams, criteria for the use of the Survey teams in evaluating existing environmental data for the Survey effort, generic technical checklists used in every Survey, health and safety guidelines for the personnel conducting the Survey, including the identification of potential hazards, prescribed protective equipment, and emergency procedures, the required formats for the Survey reports, guidance on identifying environmental problems that need immediate attention by the Operations Office responsible for the particular facility, and procedures and protocols for the conduct of sampling and analysis

  8. Sleep need in adolescents: a longitudinal approach.

    Science.gov (United States)

    Strauch, I; Meier, B

    1988-08-01

    A sample of 190 male and female "high school" students completed a sleep questionnaire for the first time when they were 10 to 14 years old. The survey was repeated five times at 2 year intervals. Ninety-three subjects answered the questionnaire each time. Subjective sleep need was assessed by the indicated wish for more sleep. The wish for more sleep was very pronounced, varying between 54.3% and 74.5% across the years. Individual consistency, however, was low since only 14.5% of the adolescents indicated the wish for more sleep in each survey, emphasizing the state dependency of this variable. Within each total sample, subjects with the wish for more sleep (MSL) and with sufficient sleep (SSL) were compared. Subjective sleep need was consistently validated by a syndrome of morning-tiredness. In the last two surveys, there was reduced time in bed (TIB) on weekdays in MSL subjects and longer TIB during vacation in surveys 2 through 5. Furthermore, MSL subjects more often showed irregular sleep habits. The previous sleep history of the MSL subjects in the last survey indicated that concomitants of the wish for more sleep were already experienced earlier in adolescence. The desired sleep duration of these subjects was 1.7 h longer than their current sleep on weekdays, an amount they had not obtained on weekdays since early adolescence. It is concluded that a substantial proportion of the adolescents seem to have had difficulties adapting to the general sleep time reduction occurring in adolescence.

  9. Longitudinal collective echoes in coasting particle beams

    Directory of Open Access Journals (Sweden)

    Ahmed Al-Khateeb

    2003-01-01

    Full Text Available Longitudinal ballistic and collective beam echoes with diffusion effects are investigated theoretically. In the presence of the space-charge impedance, the collective echo amplitude is obtained as a closed form expression. In contrast to the ballistic case, the collective echo amplitude consists of one maximum at time t_{echo}. The echo amplitude grows up and damps down with a rate proportional to the Landau damping rate of space-charge waves. The effect of weak diffusion is found to modify the ballistic and the collective echo amplitudes in the same manner. This effect of diffusion was confirmed using a “noiseless,” grid-based simulation code. As a first application the amount of numerical diffusion in our simulation code was determined using the echo effect.

  10. Granger Causality Testing with Intensive Longitudinal Data.

    Science.gov (United States)

    Molenaar, Peter C M

    2018-06-01

    The availability of intensive longitudinal data obtained by means of ambulatory assessment opens up new prospects for prevention research in that it allows the derivation of subject-specific dynamic networks of interacting variables by means of vector autoregressive (VAR) modeling. The dynamic networks thus obtained can be subjected to Granger causality testing in order to identify causal relations among the observed time-dependent variables. VARs have two equivalent representations: standard and structural. Results obtained with Granger causality testing depend upon which representation is chosen, yet no criteria exist on which this important choice can be based. A new equivalent representation is introduced called hybrid VARs with which the best representation can be chosen in a data-driven way. Partial directed coherence, a frequency-domain statistic for Granger causality testing, is shown to perform optimally when based on hybrid VARs. An application to real data is provided.

  11. Longitudinal wake field corrections in circular machines

    International Nuclear Information System (INIS)

    Symon, K.R.

    1996-01-01

    In computations of longitudinal particle motions in accelerators and storage rings, the fields produced by the interactions of the beam with the cavity in which it circulates are usually calculated by multiplying Fourier components of the beam current by the appropriate impedances. This procedure neglects the slow variation with time of the Fourier coefficients and of the beam revolution frequency. When there are cavity elements with decay times that are comparable with or larger than the time during which changes in the beam parameters occur, these changes can not be neglected. Corrections for this effect have been worked out in terms of the response functions of elements in the ring. The result is expressed as a correction to the impedance which depends on the way in which the beam parameters are changing. A method is presented for correcting a numerical simulation by keeping track of the steady state and transient terms in the response of a cavity

  12. Longitudinal magnetic bistability of electroplated wires

    International Nuclear Information System (INIS)

    Kurlyandskaya, G.V.; Garcia-Miquel, H.; Vazquez, M.; Svalov, A.V.; Vas'kovskiy, V.O.

    2002-01-01

    Fe 20 Ni 74 Co 6 and Fe 20 Ni 64 Co 16 1 μm thick magnetic tubes electroplated onto Cu 98 Be 2 conductive wire have been investigated in as-deposited state, after heat treatment under longitudinal magnetic field for 1 h at 330 deg. C, and after rf-sputtering deposition of the additional 2 μm Fe 19 Ni 81 layer. Heat treatments and an additional layer deposition modify the shape of hysteresis loops. Magnetically bistable behaviour, observed after the field annealing at a temperature of 330 deg. C, is studied as a function of the length of the samples. This is the first report by our knowledge on the bistable behaviour of the electroplated wires. The bistability of these wires is promising for applications such as tagging or pulse generator applications

  13. A Longitudinal Study of Prisoners on Remand

    DEFF Research Database (Denmark)

    Andersen, Henrik Steen; Sestoft, Dorte; Lillebæk, Tommy

    2000-01-01

    Objective: To compare two levels of stress (solitary confinement (SC) and non-SC) among remand prisoners as to incidence of psychiatric disorders in relation to prevalent disorders. Method: Longitudinal repeated assessments were carried out from the start and during the remand phase of imprisonment....... Both interview-based and self-reported measures were applied to 133 remand prisoners in SC and 95 remand prisoners in non-SC randomly selected in a parallel study design. Results: Incidence of psychiatric disorders developed in the prison was significantly higher in SC prisoners (28%) than in non......-SC prisoners (15%). Most disorders were adjustment disorders, with depressive disorders coming next. Incident psychotic disorders were rare. The difference regarding incidence was primarily explained by level of stress (i.e. prison form) rather than confounding factors. Quantitative measures of psychopathology...

  14. Beam measurements of the SPS longitudinal impedance

    CERN Document Server

    Lasheen, A

    2017-01-01

    Longitudinal instabilities are one of the main limitationsin the CERN SPS to reach the beam parameters requiredfor the High Luminosity LHC project. In preparation tothe SPS upgrade, possible remedies are studied by perform-ing macroparticle simulations using the machine impedancemodel obtained from electromagnetic simulations and mea-surements. To benchmark the impedance model, the resultsof simulations are compared with various beam measure-ments. In this study, the reactive part of the impedance wasprobed by measuring the quadrupole frequency shift withintensity, obtained from bunch length oscillations at mis-matched injection into the SPS. This method was appliedover many last years to follow up the evolution of the SPSimpedance, injecting bunches with the same bunch length.A novel approach, giving significantly more information,consists in varying the injected bunch length. The compari-son of these measurements with macroparticle simulationsallowed to test the existing model and identify some missingSPS i...

  15. Linear mixed models for longitudinal data

    CERN Document Server

    Molenberghs, Geert

    2000-01-01

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

  16. Parenting Style and Family Meals: Cross-Sectional and 5-year Longitudinal Associations

    Science.gov (United States)

    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

  17. Parenting style and family meals: cross-sectional and 5-year longitudinal associations.

    Science.gov (United States)

    Berge, Jerica M; Wall, Melanie; Neumark-Sztainer, Dianne; Larson, Nicole; Story, Mary

    2010-07-01

    Research on family meals in the past 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, that may be associated with family meal patterns. The purpose of this study is to test cross-sectional and 5-year longitudinal associations between parenting styles (authoritative, authoritarian, permissive, and neglectful) and the frequency of family meals among adolescents. Data were from Project Eating Among Teens, a population-based study comprised of youth from diverse ethnic/racial and socioeconomic backgrounds. Two cohorts of adolescents (middle school and 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. 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 5 years later, but only between opposite sex parent/adolescent dyads. Future research should identify additional factors within the home environment that are associated with family meal frequency 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 dietetics

  18. Longitudinal expansion of field line dipolarization

    Science.gov (United States)

    Saka, O.; Hayashi, K.

    2017-11-01

    We examine the substorm expansions that started at 1155 UT 10 August 1994 in the midnight sector focusing on the longitudinal (eastward) expansion of field line dipolarization in the auroral zone. Eastward expansion of the dipolarization region was observed in all of the H, D, and Z components. The dipolarization that started at 1155 UT (0027 MLT) from 260° of geomagnetic longitude (CMO) expanded to 351°(PBQ) in about 48 min. The expansion velocity was 0.03-0.04°/s, or 1.9 km/s at 62°N of geomagnetic latitude. The dipolarization region expanding to the east was accompanied by a bipolar event at the leading edge of the expansion in latitudes equatorward of the westward electrojet (WEJ). In the midnight sector at the onset meridian, the Magnetospheric Plasma Analyzer (MAP) on board geosynchronous satellite L9 measured electrons and ions between 10 eV and 40 keV. We conclude from the satellite observations that this dipolarization was characterized by the evolution of temperature anisotropies, an increase of the electron and ion temperatures, and a rapid change in the symmetry axis of the temperature tensor. The field line dipolarization and its longitudinal expansion were interpreted in terms of the slow MHD mode triggered by the current disruption. We propose a new magnetosphere-ionosphere coupling (MI-coupling) mechanism based on the scenario that transmitted westward electric fields from the magnetosphere in association with expanding dipolarization produced electrostatic potential (negative) in the ionosphere through differences in the mobility of collisional ions and collisionless electrons. The field-aligned currents that emerged from the negative potential region are arranged in a concentric pattern around the negative potential region, upward toward the center and downward on the peripheral.

  19. Longitudinal prediction of divorce in Russia: the role of individual and couple drinking patterns.

    Science.gov (United States)

    Keenan, Katherine; Kenward, Michael G; Grundy, Emily; Leon, David A

    2013-01-01

    The aim of the study was to explore associations between dimensions of alcohol use in married couples and subsequent divorce in Russia using longitudinal data. Follow-up data on 7157 married couples were extracted from 14 consecutive annual rounds (1994-2010) of the Russian Longitudinal Monitoring Survey, a national population-based panel study. Discrete-time hazard models were fitted to estimate the probability of divorce among married couples by drinking patterns reported in the previous survey wave. In adjusted models, increased odds of divorce were associated with greater frequency of husband and wife drinking (test for trend P = 0.005, and P = 0.05, respectively), wife's binge drinking (P = 0.05) and husband's heavy vodka drinking (P = 0.005). Couples in whom the wife drank more frequently than the husband were more likely to divorce (OR 2.86, 95% CI 1.52-5.36), compared with other combinations of drinking. The association between drinking and divorce was stronger in regions outside Moscow or St. Petersburg. This study adds to the sparse literature on the topic and suggests that in Russia heavy and frequent drinking of both husbands and wives put couples at greater risk of future divorce, with some variation by region and aspect of alcohol use.

  20. Social phobia, depression and eating disorders during middle adolescence: longitudinal associations and treatment seeking.

    Science.gov (United States)

    Ranta, Klaus; Väänänen, Juha; Fröjd, Sari; Isomaa, Rasmus; Kaltiala-Heino, Riittakerttu; Marttunen, Mauri

    2017-11-01

    Longitudinal associations between social phobia (SP), depression and eating disorders (EDs), and the impact of antecedent SP and depression on subsequent treatment seeking for EDs have rarely been explored in prospective adolescent population studies. We aimed to examine these associations in a large-scale follow-up study among middle adolescents. We surveyed 3278 Finnish adolescents with a mean age of 15 years for these disorders. Two years later, 2070 were reached and again surveyed for psychopathology and treatment seeking. Longitudinal associations between the self-reported disorders and treatment-seeking patterns for self-acknowledged ED symptoms were examined in multivariate analyses, controlling for SP/depression comorbidity and relevant socioeconomic covariates. Self-reported anorexia nervosa (AN) at age 15 years predicted self-reported depression at age 17 years. Furthermore, self-reported SP at age 15 years predicted not seeking treatment for bulimia nervosa (BN) symptoms, while self-reported depression at age 15 years predicted not seeking treatment for AN symptoms during the follow-up period. Adolescents with AN should be monitored for subsequent depression. Barriers caused by SP to help seeking for BN, and by depression for AN, should be acknowledged by healthcare professionals who encounter socially anxious and depressive adolescents, especially when they present with eating problems.

  1. Closing the gap: Longitudinal changes in employment for Australians with multiple sclerosis.

    Science.gov (United States)

    Van Dijk, Pieter A; Kirk-Brown, Andrea K; Taylor, Bruce; van der Mei, Ingrid

    2017-09-01

    Previous studies have documented far lower employment participation rates for people with multiple sclerosis (PwMS) compared to the general population. In a large national sample of PwMS, we examined employment status, longitudinal changes in employment and the provision of modifications to work role/environment from 2010 to 2013. Employment data were collected through the Australian MS Longitudinal Study from 2010 to 2013, with 1260 people responding to all four surveys. Employment rates were compared with the Australian general population. The survey included questions on the provision of modifications to employees' work role and work environment. Employment (full- and part-time) increased from 48.8% in 2010 to 57.8% in 2013, mainly due to increases in male full-time employment. The employment gap between PwMS and the general population fell from 14.3% in 2010 to 3.5% in 2013. Male employment rates, however, remain significantly lower than the general population. The majority of PwMS who required adjustments to either their work role or environment received them. The gap in employment between PwMS and the general population has substantially reduced from 2010 to 2013, with organisations responding positively to requests for work role/environment adjustments.

  2. Association of Longitudinal Changes of Physical Activity on Smoking Cessation Among Young Daily Smokers.

    Science.gov (United States)

    Loprinzi, Paul D; Walker, Jerome F

    2016-01-01

    To our knowledge, no longitudinal epidemiological study among daily smokers has examined the effects of physical activity change/ trajectory on smoking cessation. The purpose of this study was to examine the longitudinal effects of changes in physical activity on smoking cessation among a national sample of young (16-24 y) daily smokers. Data from the 2003-2005 National Youth Smoking Cessation Survey were used (N = 1178). Using hierarchical agglomerative cluster analysis, 5 distinct self-reported physical activity trajectories over 3 time periods (baseline, 12-month, and 24-month follow-up) were observed, including stable low physical activity, decreasing physical activity, curvilinear physical activity, stable high physical activity, and increasing physical activity. Nicotine dependence (Heaviness of Smoking Index) and demographic parameters were assessed via survey. With stable low physical activity (16.2% quit smoking) serving as the referent group, those in the stable high physical activity (24.8% quit smoking) group had 1.8 greater odds of not smoking at the 24-month follow-up period (odds ratio = 1.81; 95% confidence interval, 1.12-2.91) after adjusting for nicotine dependence, age, gender, race-ethnicity, and education. Maintenance of regular physical activity among young daily smokers may help to facilitate smoking cessation.

  3. From student to graduate: longitudinal changes in the qualities of nurses.

    Science.gov (United States)

    Cowin, Leanne S; Johnson, Maree

    2015-12-01

    To examine the development of perceived qualities of nursing from student to graduate nurse over time. Researchers continue to explore student nurse and new graduate nurse attrition, particularly in the light of a looming crisis in nursing recruitment and retention. Qualities of nurses represent the job fit of nursing from student to graduate years. A prospective longitudinal design with a convenience sample was used for this study. Data were collected annually from 2009-2012 through the completion of a short on-line survey. The sample size of undergraduate nurses in year 1 was 676, with 527 in year 2, 339 in year 3 and 190 in year 4. Only 136 participants completed the survey each year forming the complete data set for analysis. Most qualities of nursing differed significantly across time with the qualities of Caring, Empathetic, Knowledge and Respectful demonstrating strong changes. Most declines in scores occurred on graduation. Caring, the central tenet of nursing increased during the student years and declined slightly on graduation. This unique longitudinal study of Australian nurses suggests that the clinical experience and theoretical grounding provided in our University programs, has resulted in an increasing cumulative effect in the third year supporting most qualities of nurses/nursing understood in year 1, that is, the career fit to perceptions, has been achieved. The decline in the 1(st) year of graduation, where the concept of workplace misfit is occurring, is where further nurse graduate support is urgently required. © 2015 John Wiley & Sons Ltd.

  4. Distinct longitudinal patterns of absenteeism and their antecedents in full-time Australian employees.

    Science.gov (United States)

    Magee, Christopher A; Caputi, Peter; Lee, Jeong Kyu

    2016-01-01

    This paper investigated distinct longitudinal trajectories of absenteeism over time, and underlying demographic, work, and health antecedents. Data from the Household, Income, and Labor Dynamics in Australia Survey were used; this is a panel study of a representative sample of Australian households. This paper focused on 2,481 full-time employees across a 5-year period. Information on annual sick leave and relevant sociodemographic, work, and health-related factors was collected through interviews and self-completed surveys. Growth mixture modeling indicated 4 distinct longitudinal patterns of absenteeism over time. The moderate absenteeism trajectory (34.8%) of the sample had 4-5 days of sick leave per year and was used as the reference group. The low absenteeism trajectory (33.5%) had 1-2 days of absenteeism per year, while the no absenteeism trajectory (23.6%) had very low rates of absenteeism (absenteeism (>11 days per year). Compared with the moderate absenteeism trajectory, the high absenteeism trajectory was characterized by poor health; the no absenteeism and low absenteeism trajectories had better health but may also reflect processes relating to presenteeism. These results provide important insights into the nature of absenteeism in Australian employees, and suggest that different patterns of absenteeism over time could reflect a range of demographic, work, and health related factors. (c) 2016 APA, all rights reserved).

  5. Antisocial Behavior and Depressive Symptoms: Longitudinal and Concurrent Relations

    Science.gov (United States)

    Vieno, Alessio; Kiesner, Jeff; Pastore, Massimiliano; Santinello, Massimo

    2008-01-01

    The relations between antisocial behavior and depressive symptoms were examined both longitudinally and concurrently in a sample of Italian early-adolescents. Structural equation modelling was applied to 10-month longitudinal data from a sample of 107 youths (54 girls; mean age at baseline = M = 12.5). Early adolescents completed a questionnaire…

  6. Future Orientation, Impulsivity, and Problem Behaviors: A Longitudinal Moderation Model

    Science.gov (United States)

    Chen, Pan; Vazsonyi, Alexander T.

    2011-01-01

    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;…

  7. Physics and technology of tunable pulsed single longitudinal mode ...

    Indian Academy of Sciences (India)

    precious materials. In particular, single-longitudinal mode dye lasers are useful ... to the longitudinal mode spacing of 10 GHz. Grating of 3300 .... the band of wavelength covering 3 pm and SLM operation was shown in the band of 0.5 pm.

  8. 14 CFR 23.173 - Static longitudinal stability.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Static longitudinal stability. 23.173... Stability § 23.173 Static longitudinal stability. Under the conditions specified in § 23.175 and with the airplane trimmed as indicated, the characteristics of the elevator control forces and the friction within...

  9. A Longitudinal Study of Adolescent Adjustment Following Family Transitions

    Science.gov (United States)

    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…

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

    Science.gov (United States)

    Vanderstaay, Steven L.

    2006-01-01

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

  11. Longitudinal and transverse polarizations in the deep inelastic reactions

    International Nuclear Information System (INIS)

    Bressan, A.

    1996-07-01

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

  12. Simulation of the longitudinal instabilities of the asymmetric bunches

    International Nuclear Information System (INIS)

    Dai Jianping; Zhao Zhentang

    2002-01-01

    The computational model of the code used to simulate the longitudinal instabilities of the asymmetric bunches was introduced. The growth rates of the longitudinal instabilities of the symmetric bunches got by this code were compared with those got by the code ZAP, and they were almost the same. As an example, the simulation results of the BEPC-II were presented

  13. Aerial radiation surveys

    International Nuclear Information System (INIS)

    Jobst, J.

    1980-01-01

    A recent aerial radiation survey of the surroundings of the Vitro mill in Salt Lake City shows that uranium mill tailings have been removed to many locations outside their original boundary. To date, 52 remote sites have been discovered within a 100 square kilometer aerial survey perimeter surrounding the mill; 9 of these were discovered with the recent aerial survey map. Five additional sites, also discovered by aerial survey, contained uranium ore, milling equipment, or radioactive slag. Because of the success of this survey, plans are being made to extend the aerial survey program to other parts of the Salt Lake valley where diversions of Vitro tailings are also known to exist

  14. Social support and health-related quality of life in women with breast cancer: a longitudinal study.

    Science.gov (United States)

    Leung, Janni; Pachana, Nancy A; McLaughlin, Deirdre

    2014-09-01

    A breast cancer diagnosis is a distressing event that impacts on physical and psychological functioning. This study examined the longitudinal relationships among a diagnosis of breast cancer, social support, and health-related quality of life (HRQOL). Participants were 412 women from the 1946-1951 birth cohort of the Australian Longitudinal Study on Women's Health who self-reported a new diagnosis of breast cancer between 1998 and 2007. The three surveys of longitudinal data analyzed included data 3 years before diagnosis, at diagnosis (baseline), and 3 years after diagnosis (follow-up). Social support was measured using the 19-item Medical Outcomes Study Social Support Survey; HRQOL was measured using the Medical Outcomes Study 36-item Short-Form Health Survey. Compared with pre-diagnosis HRQOL, women newly diagnosed with breast cancer reported significantly poorer HRQOL in subscales related to pain, physical functioning, and health and vitality. At 3-year follow-up, HRQOL had improved in most domains to levels consistent with pre-diagnosis. Levels of social support remained stable across time. The structural equation model showed that social support was positively predictive of better physical and mental HRQOL at 3-year follow-up. Longitudinal analyses indicate that social support appears to be an important predictor of HRQOL in women diagnosed with breast cancer. In particular, positive emotional and informational support that may normally be provided by a partner is important in maintaining HRQOL. Identification of those lacking social support, especially patients without partners, will enable them to be guided to appropriate support networks and programs. Copyright © 2014 John Wiley & Sons, Ltd.

  15. Requirements for longitudinal HOM damping in superconducting recirculating linacs

    International Nuclear Information System (INIS)

    Bisognano, J.J.; Fripp, M.L.

    1989-01-01

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

  16. Longitudinal Control for Mengshi Autonomous Vehicle via Gauss Cloud Model

    Directory of Open Access Journals (Sweden)

    Hongbo Gao

    2017-12-01

    Full Text Available Dynamic robustness and stability control is a requirement for self-driving of autonomous vehicle. Longitudinal control technique of autonomous vehicle is basic theory and one key complex technique which must have the reliability and precision of vehicle controller. The longitudinal control technique is one of the foundations of the safety and stability of autonomous vehicle control. In our paper, we present a longitudinal control algorithm based on cloud model for Mengshi autonomous vehicle to ensure the dynamic stability and tracking performance of Mengshi autonomous vehicle. The longitudinal control algorithm mainly uses cloud model generator to control the acceleration of the autonomous vehicle to achieve the goal that controls the speed of Mengshi autonomous vehicle. The proposed longitudinal control algorithm based on cloud model is verified by real experiments on Highway driving scene. The experiments results of the acceleration and speed show that the algorithm is validity and stability.

  17. Sequential Progressions in a Theory of Mind Scale: Longitudinal Perspectives

    Science.gov (United States)

    Wellman, Henry M.; Fuxi, Fang; Peterson, Candida C.

    2011-01-01

    Consecutive re-testings of 92 U.S. preschoolers (n = 30), Chinese preschoolers (n = 31), and deaf children (n = 31) examined whether the sequences of development apparent in cross-sectional results with a theory-of-mind scale also appeared in longitudinal assessment. Longitudinal data confirmed that theory-of-mind progressions apparent in cross-sectional scaling data also characterized longitudinal sequences of understanding for individual children. The match between cross-sectional and longitudinal sequences appeared for children who exhibit different progressions across cultures (U.S. vs. China) and for children with substantial delays (deaf children of hearing parents). Moreover, greater scale distances reflected larger longitudinal age differences. PMID:21428982

  18. Authentication Architecture for Region-Wide e-Health System with Smartcards and a PKI

    Science.gov (United States)

    Zúquete, André; Gomes, Helder; Cunha, João Paulo Silva

    This paper describes the design and implementation of an e-Health authentication architecture using smartcards and a PKI. This architecture was developed to authenticate e-Health Professionals accessing the RTS (Rede Telemática da Saúde), a regional platform for sharing clinical data among a set of affiliated health institutions. The architecture had to accommodate specific RTS requirements, namely the security of Professionals' credentials, the mobility of Professionals, and the scalability to accommodate new health institutions. The adopted solution uses short-lived certificates and cross-certification agreements between RTS and e-Health institutions for authenticating Professionals accessing the RTS. These certificates carry as well the Professional's role at their home institution for role-based authorization. Trust agreements between e-Health institutions and RTS are necessary in order to make the certificates recognized by the RTS. As a proof of concept, a prototype was implemented with Windows technology. The presented authentication architecture is intended to be applied to other medical telematic systems.

  19. Evaluating a biomass resource: The TVA region-wide biomass resource assessment model

    International Nuclear Information System (INIS)

    Downing, M.; Graham, R.L.

    1993-01-01

    Wood is an alterative fuel for electric power generation at coal-fired plants in the Tennessee Valley Authority (TVA) region. Short rotation wood energy crops (SRWC) could provide a source of this woody biomass. However, the economic and supply structures of SRWC markets have not been established. Establishing the likely price and supply of SRWC biomass in a region is a complex task because biomass is not an established commodity as are oil, natural gas and coal. In this study we project the cost and supply of short-rotation woody biomass for the TVA region -- a 276 county area that includes all of Tennessee and portions of 10 contiguous states in the southeastern United States. Projected prices and quantities of SRWC are assumed to be a function of the amount and quality of crop and pasture land available in a region. expected SRWC yields and production costs on differing soils and land types, and the profit that could be obtained from current conventional crop production on these same lands. Results include the supply curve of SRWC biomass that is projected to be available from the entire region, the amount and location of crop and pasture land that would be used, and the conventional agricultural crops that would be displaced as a function of SRWC production. Finally, we show the results of sensitivity analysis on the projected cost and supply of SRWC biomass. In particular, we examine the separate impacts of varying SRWC production yields

  20. Area burned in alpine treeline ecotones reflects region-wide trends

    Science.gov (United States)

    C. Alina Cansler; Donald McKenzie; Charles B. Halpern

    2016-01-01

    The direct effects of climate change on alpine treeline ecotones – the transition zones between subalpine forest and non-forested alpine vegetation – have been studied extensively, but climate-induced changes in disturbance regimes have received less attention. To determine if recent increases in area burned extend to these higher-elevation landscapes, we analysed...

  1. A Lightweight Modeling System for Region-Wide Monitoring of Hydrologic Threats

    Science.gov (United States)

    Luna, D.; Hernandez, F.; Wang, R.; Liang, Y.; Teng, W. L.; Liang, X.

    2016-12-01

    Transportation infrastructure is subject to multiple hydrology-related threats, including floods, bridge scouring, landslides, and icing. While modern land-surface models could potentially assist in forecast and response operations, applying these models is challenging, because of the extensiveness of the infrastructure that the government transportation agencies are responsible for. Constructing detailed models for every point of interest and running them in real time would require significant efforts from a team of modeling professionals and considerable computational resources. To address this challenge, we introduce the Hydrologic Disaster Forecast and Response (HDFR) system, a lightweight software framework (under development) that streamlines the process of acquiring real-time and forecast data, inputting it into hydrologic models, and translating the results into concrete actionable information for field-team deployment. HDFR integrates a series of data, modeling, and severity modules behind a unified GIS graphical user interface. The latter interface allows non-expert users to easily execute complex workflows, ranging from forcing information acquisition to severity level computations at specific locations. The HDFR allows the performance of these monitoring tasks without the need of a supercomputer-grade infrastructure. Currently, the HDFR uses a regression algorithm as a proxy for physically-based models, to estimate return periods of variables of interest for watersheds of concern, based on key forcing and state variables (e.g., precipitation, soil moisture). This method only requires the execution of land-surface simulations during an offline training phase; however, the HDFR also features a hierarchical multi-scale modeling strategy for improved forecast precision. This approach minimizes the number of models runs to those for selected areas and resolutions, depending on observed conditions. Several prototype versions of the HDFR built on GRASS GIS have been deployed for the Pennsylvania Department of Transportation (PennDOT). They have already shown to be able to considerably increase the accuracy in the identification of scour-critical bridges after severe storms, while significantly reducing the workload on PennDOT's engineering teams.

  2. Evaluating a biomass resource: The TVA region-wide biomass resource assessment model

    Energy Technology Data Exchange (ETDEWEB)

    Downing, M.; Graham, R.L. [Oak Ridge National Lab., TN (United States)

    1993-12-31

    The economic and supply structures of short rotation woody crop (SRWC) markets have not been established. Establishing the likely price and supply of SRWC biomass in a region is a complex task because biomass is not an established commodity as are oil, natural gas and coal. In this study we project the cost and supply of short-rotation woody biomass for the TVA region -- a 276 county area that includes all of Tennessee and portions of 10 contiguous states in the southeastern United States. Projected prices and quantities of SRWC are assumed to be a function of the amount and quality of crop and pasture land available in a region, expected SRWC yields and production costs on differing soils and land types, and the profit that could be obtained from current conventional crop production on these same lands. Results include the supply curve of SRWC biomass that is projected to be available from the entire region, the amount and location of crop and pasture land that would be used, and the conventional agricultural crops that would be displaced as a function of SRWC production. Finally, we show the results of sensitivity analysis on the projected cost and supply of SRWC biomass. In particular, we examine the separate impacts of varying SRWC production yields.

  3. Cohort profile: the Motorik-Modul Longitudinal Study: physical fitness and physical activity as determinants of health development in German children and adolescents.

    Science.gov (United States)

    Wagner, Matthias O; Bös, Klaus; Jekauc, Darko; Karger, Claudia; Mewes, Nadine; Oberger, Jennifer; Reimers, Anne K; Schlenker, Lars; Worth, Annette; Woll, Alexander

    2014-10-01

    The Motorik-Modul (MoMo) Longitudinal Study aims to contribute to long-term improvement in the health of German children and adolescents by focusing on: (i) the development of physical fitness and physical activity (including period effects); (ii) the individual and physical/social environmental determinants of the development of physical fitness and physical activity; and (iii) the impact of physical fitness and physical activity on the development of physical and mental health. The MoMo Longitudinal Study began with a nationwide representative sample of 4529 children and adolescents who ranged in age from 4-17 years at the study baseline (2003-2006). The first survey wave of the MoMo Longitudinal Study was conducted between 2009 and 2012, with two subsequent survey waves to be conducted between 2014 and 2016 and 2018 and 2020, respectively. The MoMo Longitudinal Study includes a physical fitness test profile, a physical activity questionnaire, and subjective and objective measures of health from the German Health Interview and Examination Survey (KiGGS). Data access is provided on request (alexander.woll@kit.edu). For further information, including a complete list of publications please visit www.motorik-modul.de. Published by Oxford University Press on behalf of the International Epidemiological Association © The Author 2013; all rights reserved.

  4. Successful Youth Transitions. Longitudinal Surveys of Australian Youth. Briefing Paper 25

    Science.gov (United States)

    Liu, Shu-Hui; Nguyen, Nhi

    2011-01-01

    Youth transitions refer to young people's journeys from school to post-school study and on to employment. This is a time when young people experience rapid biological, psychological and physical changes, as well as changing social and economic situations, as they begin to take on the responsibilities of adulthood. In this paper, the authors first…

  5. Young People in an Economic Downturn. Longitudinal Surveys of Australian Youth. Briefing Paper 23

    Science.gov (United States)

    Anlezark, Alison

    2011-01-01

    Following the collapse of the US investment bank Lehmann Brothers in September 2008, the world economy began a downward spiral, with many countries falling into recession. Australia experienced significant stock market losses and unemployment rates began to climb. This briefing paper considers how young people fared in previous downturns and…

  6. Social Capital and Young People. Longitudinal Surveys of Australian Youth. Briefing Paper 26

    Science.gov (United States)

    Semo, Ronnie

    2011-01-01

    Social capital refers to the attributes and qualities of family, social and community networks that facilitate cooperation between individuals and communities. The quality of these networks and the extent to which individuals are engaged with them are believed to have an impact on the educational and social development of children and young…

  7. Who Takes a Gap Year and Why? Longitudinal Surveys of Australian Youth. Briefing Paper 28

    Science.gov (United States)

    Lumsden, Marilyn; Stanwick, John

    2012-01-01

    Taking a gap year--a break between high school and university--is becoming increasingly popular with Australian students. In terms of length and purpose, the traditional notion of a gap year being a year off between school and university has expanded considerably over time. For the purposes of the analysis reported in this paper, a person who…

  8. Adverse childhood experiences and mental health in young adults: a longitudinal survey

    Directory of Open Access Journals (Sweden)

    Aseltine Robert H

    2007-03-01

    Full Text Available Abstract Background Adverse childhood experiences (ACEs have been consistently linked to psychiatric difficulties in children and adults. However, the long-term effects of ACEs on mental health during the early adult years have been understudied. In addition, many studies are methodologically limited by use of non-representative samples, and few studies have investigated gender and racial differences. The current study relates self-reported lifetime exposure to a range of ACEs in a community sample of high school seniors to three mental health outcomes–depressive symptoms, drug abuse, and antisocial behavior–two years later during the transition to adulthood. Methods The study has a two-wave, prospective design. A systematic probability sample of high school seniors (N = 1093 was taken from communities of diverse socioeconomic status. They were interviewed in person in 1998 and over the telephone two years later. Gender and racial differences in ACE prevalence were tested with chi-square tests. Each mental health outcome was regressed on one ACE, controlling for gender, race/ethnicity, and SES to obtain partially standardized regression coefficients. Results Most ACEs were strongly associated with all three outcomes. The cumulative effect of ACEs was significant and of similar magnitude for all three outcomes. Except for sex abuse/assault, significant gender differences in the effects of single ACEs on depression and drug use were not observed. However, boys who experienced ACEs were more likely to engage in antisocial behavior early in young adulthood than girls who experienced similar ACEs. Where racial/ethnic differences existed, the adverse mental health impact of ACEs on Whites was consistently greater than on Blacks and Hispanics. Conclusion Our sample of young adults from urban, socio-economically disadvantaged communities reported high rates of adverse childhood experiences. The public health impact of childhood adversity is evident in the very strong association between childhood adversity and depressive symptoms, antisocial behavior, and drug use during the early transition to adulthood. These findings, coupled with evidence that the impact of major childhood adversities persists well into adulthood, indicate the critical need for prevention and intervention strategies targeting early adverse experiences and their mental health consequences.

  9. Attrition from Military and Civilian Jobs: Insights from the National Longitudinal Surveys

    Science.gov (United States)

    1984-07-01

    Smith. Modern Labor Economics (Glenvi^v, IL: Scott Foresman, 1982). Fredland, J. E. and R. D. Little. oc oeconomic Char eteriatic3 of the All... Labor Economics (Greenwich, CTt JAI Press, 1977). Parsons, D. 0. "Quit Rates Over Time: A Search and Information Approach," American Economic Review 63

  10. Factors Influencing Youth Unemployment in Australia: 1980-1994. Longitudinal Surveys of Australian Youth. Research Report.

    Science.gov (United States)

    Marks, Gary N.; Fleming, Nicole

    A study examined unemployment among Australian young people between 1980-94, using data obtained from the four Youth in Transition cohorts born in 1961, 1965, 1970, and 1975. It investigated factors that influenced becoming unemployed and leaving unemployment. Findings indicated that low school achievement in literacy and numeracy was consistently…

  11. Employer Learning and the Signaling Value of Education. National Longitudinal Surveys Discussion Paper.

    Science.gov (United States)

    Altonji, Joseph G.; Pierret, Charles R.

    A statistical analysis was performed to test the hypothesis that, if profit-maximizing firms have limited information about the general productivity of new workers, they may choose to use easily observable characteristics such as years of education to discriminate statistically among workers. Information about employer learning was obtained by…

  12. Reputation Enhancement and School Delinquency: A Prospective Study Using the National Educational Longitudinal Survey [NELS:88

    Science.gov (United States)

    Smith-Adcock, Sondra; Lee, Sang Min; Kerpelman, Jennifer; Majuta, Aaron; Young, Choi Bo

    2013-01-01

    High school delinquency, adolescent behaviors ranging from repeated school misconduct to being arrested, is a critical concern in the United States. Though widely believed that reputation is related to adolescent behavior, few studies have addressed the relationship between adolescent reputation and delinquency. Using the National Educational…

  13. The growing commercial value of the male body: a longitudinal survey of advertising in women's magazines.

    Science.gov (United States)

    Pope, H G; Olivardia, R; Borowiecki, J J; Cohane, G H

    2001-01-01

    With the advances of feminism, men have gradually relinquished their once-exclusive 'masculine' roles as fighters and breadwinners. In response to this change, the male body may have gained in relative importance as one of the few surviving marks of masculinity. We hypothesized that these trends might be quantified by using a commercial measure such as advertising. We examined the proportion of exposed male and female bodies portrayed in advertisements between 1958 and 1998 in two leading American women's magazines. In both magazines, the proportion of undressed women in the advertisements has changed little over the last 40 years, whereas the proportion of undressed men has increased dramatically, especially since the early 1980s. Trends in commercial advertising offer tentative support for the hypothesis that the male body is increasing in importance as a mark of masculinity--at least as judged from the actions of advertisers seeking to influence women's attitudes. Copyright 2001 S. Karger AG, Basel.

  14. SURVEY, BUFFALO COUNTY, NE

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Survey data includes spatial datasets and data tables necessary to digitally represent data collected in the survey phase of the study. (Source: FEMA Guidelines and...

  15. Patient survey (HCAHPS) - National

    Data.gov (United States)

    U.S. Department of Health & Human Services — The national average for the HCAHPS survey categories. HCAHPS is a national, standardized survey of hospital patients about their experiences during a recent...

  16. Survey, OCONEE COUNTY, SC

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Survey data includes spatial datasets and data tables necessary to digitally represent data collected in the survey phase of the study. (Source: FEMA Guidelines and...

  17. SURVEY, DOUGLAS COUNTY, MN

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Survey data includes spatial datasets and data tables necessary to digitally represent data collected in the survey phase of the study. (Source: FEMA Guidelines and...

  18. GDOT employee survey.

    Science.gov (United States)

    2017-07-04

    The research team worked in collaboration with GDOT to conduct the 2016 GDOT Employee Survey. This research study aimed to increase the response rate and the usefulness of the feedback from the GDOT employee survey to support organizational decisions...

  19. SURVEY, KENAI PENINSULSA, AK

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Survey data includes spatial datasets and data tables necessary to digitally represent data collected in the survey phase of the study. (Source: FEMA Guidelines and...

  20. SURVEY, BROADWATER COUNTY, MT

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Survey data includes spatial datasets and data tables necessary to digitally represent data collected in the survey phase of the study. (Source: FEMA Guidelines and...

  1. SURVEY, OSCEOLA COUNTY, FLORIDA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Survey data includes spatial datasets and data tables necessary to digitally represent data collected in the survey phase of the study. (Source: FEMA Guidelines and...

  2. SURVEY, POTTAWATTAMIE COUNTY, IA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Survey data includes spatial datasets and data tables necessary to digitally represent data collected in the survey phase of the study. (Source: FEMA Guidelines and...

  3. Large Pelagics Intercept Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Large Pelagics Intercept Survey (LPIS) is a dockside survey of private and charterboat captains who have just completed fishing trips directed at large pelagic...

  4. MAX and Survey Linkages

    Data.gov (United States)

    U.S. Department of Health & Human Services — CMS is interested in linking MAX files with survey data, including four surveys conducted by the National Center for Health Statistics (NCHS) - the National Health...

  5. SURVEY, LAKE COUNTY, MT

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Survey data includes spatial datasets and data tables necessary to digitally represent data collected in the survey phase of the study. (Source: FEMA Guidelines and...

  6. NGS Survey Control Map

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NGS Survey Control Map provides a map of the US which allows you to find and display geodetic survey control points stored in the database of the National...

  7. SURVEY, Lowndes County, MS

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Survey data includes spatial datasets and data tables necessary to digitally represent data collected in the survey phase of the study. (Source: FEMA Guidelines and...

  8. SURVEY, REFUGIO COUNTY, TEXAS

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Survey data includes spatial datasets and data tables necessary to digitally represent data collected in the survey phase of the study. (Source: FEMA Guidelines and...

  9. SURVEY, FAIRFIELD COUNTY, CT

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Survey data includes spatial datasets and data tables necessary to digitally represent data collected in the survey phase of the study. (Source: FEMA Guidelines and...

  10. Designing an Effective Survey

    National Research Council Canada - National Science Library

    Kasunic, Mark

    2005-01-01

    ... of them. However, to protect the validity of conclusions drawn from a survey, certain procedures must be followed throughout the process of designing, developing, and distributing the survey questionnaire...

  11. Sea Scallop Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The standardized NEFSC Sea Scallop Survey began in 1980 and has covered an area from Cape Hatteras to Georges Bank. The survey aims to determine the distribution and...

  12. SURVEY, MISSOULA COUNTY, MT

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Survey data includes spatial datasets and data tables necessary to digitally represent data collected in the survey phase of the study. (Source: FEMA Guidelines and...

  13. SURVEY, Northumberland County, VA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — The field survey data for this coastal study includes a field report that exhibits photos and transect information collected in the field survey phase of the study....

  14. SURVEY, BARNSTABLE COUNTY, MA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Survey data includes spatial datasets and data tables necessary to digitally represent data collected in the survey phase of the study. (Source: FEMA Guidelines and...

  15. SURVEY, CASCADE COUNTY, MT

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Survey data includes spatial datasets and data tables necessary to digitally represent data collected in the survey phase of the study. (Source: FEMA Guidelines and...

  16. SURVEY, NATCHITOCHES PARISH, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Survey data includes spatial datasets and data tables necessary to digitally represent data collected in the survey phase of the study. (Source: FEMA Guidelines and...

  17. SURVEY, HOLMES COUNTY, MS

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Survey data includes spatial datasets and data tables necessary to digitally represent data collected in the survey phase of the study. (Source: FEMA Guidelines and...

  18. Iowa Intensive Archaeological Survey

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — This shape file contains intensive level archaeological survey areas for the state of Iowa. All intensive Phase I surveys that are submitted to the State Historic...

  19. SURVEY, MONO COUNTY, CALIFORNIA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Survey data includes spatial datasets and data tables necessary to digitally represent data collected in the survey phase of the study. (Source: FEMA Guidelines and...

  20. AIC identifies optimal representation of longitudinal dietary variables.

    Science.gov (United States)

    VanBuren, John; Cavanaugh, Joseph; Marshall, Teresa; Warren, John; Levy, Steven M

    2017-09-01

    The Akaike Information Criterion (AIC) is a well-known tool for variable selection in multivariable modeling as well as a tool to help identify the optimal representation of explanatory variables. However, it has been discussed infrequently in the dental literature. The purpose of this paper is to demonstrate the use of AIC in determining the optimal representation of dietary variables in a longitudinal dental study. The Iowa Fluoride Study enrolled children at birth and dental examinations were conducted at ages 5, 9, 13, and 17. Decayed or filled surfaces (DFS) trend clusters were created based on age 13 DFS counts and age 13-17 DFS increments. Dietary intake data (water, milk, 100 percent-juice, and sugar sweetened beverages) were collected semiannually using a food frequency questionnaire. Multinomial logistic regression models were fit to predict DFS cluster membership (n=344). Multiple approaches could be used to represent the dietary data including averaging across all collected surveys or over different shorter time periods to capture age-specific trends or using the individual time points of dietary data. AIC helped identify the optimal representation. Averaging data for all four dietary variables for the whole period from age 9.0 to 17.0 provided a better representation in the multivariable full model (AIC=745.0) compared to other methods assessed in full models (AICs=750.6 for age 9 and 9-13 increment dietary measurements and AIC=762.3 for age 9, 13, and 17 individual measurements). The results illustrate that AIC can help researchers identify the optimal way to summarize information for inclusion in a statistical model. The method presented here can be used by researchers performing statistical modeling in dental research. This method provides an alternative approach for assessing the propriety of variable representation to significance-based procedures, which could potentially lead to improved research in the dental community. © 2017 American

  1. A competency-based longitudinal core curriculum in medical neuroscience.

    Science.gov (United States)

    Merlin, Lisa R; Horak, Holli A; Milligan, Tracey A; Kraakevik, Jeff A; Ali, Imran I

    2014-07-29

    Current medical educational theory encourages the development of competency-based curricula. The Accreditation Council for Graduate Medical Education's 6 core competencies for resident education (medical knowledge, patient care, professionalism, interpersonal and communication skills, practice-based learning, and systems-based practice) have been embraced by medical schools as the building blocks necessary for becoming a competent licensed physician. Many medical schools are therefore changing their educational approach to an integrated model in which students demonstrate incremental acquisition and mastery of all competencies as they progress through medical school. Challenges to medical schools include integration of preclinical and clinical studies as well as development of learning objectives and assessment measures for each competency. The Undergraduate Education Subcommittee (UES) of the American Academy of Neurology (AAN) assembled a group of neuroscience educators to outline a longitudinal competency-based curriculum in medical neuroscience encompassing both preclinical and clinical coursework. In development of this curriculum, the committee reviewed United States Medical Licensing Examination content outlines, Liaison Committee on Medical Education requirements, prior AAN-mandated core curricula for basic neuroscience and clinical neurology, and survey responses from educators in US medical schools. The newly recommended curriculum provides an outline of learning objectives for each of the 6 competencies, listing each learning objective in active terms. Documentation of experiences is emphasized, and assessment measures are suggested to demonstrate adequate achievement in each competency. These guidelines, widely vetted and approved by the UES membership, aspire to be both useful as a stand-alone curriculum and also provide a framework for neuroscience educators who wish to develop a more detailed focus in certain areas of study. © 2014 American Academy

  2. Primer on Health Surveys

    OpenAIRE

    David L Nordstrom; David L Nordstrom

    2012-01-01

    The aim of this paper is to introduce novice researchers to surveys as a method of data collection. It starts with the definition of a survey, its major purposes and types as well as changes in the goals surveys have helped to achieve over time. Advantages and disadvantages of surveys over population censuses and medical examinations are discussed. Approaches to questionnaire construction are introduced along with properties that questionnaires are evaluated for. Modes of administration, sam...

  3. Surveying ethnic minorities

    NARCIS (Netherlands)

    Joost Kappelhof

    2015-01-01

    Obtaining accurate survey data on ethnic minorities is not easy. Ethnic minorities are usually underrepresented in surveys, and it is moreover not certain that those who do take part in surveys are representative of the group the researcher is interested in. For example, is it only people with

  4. GIS Readiness Survey 2014

    DEFF Research Database (Denmark)

    Schrøder, Lise; Hvingel, Line Træholt; Hansen, Henning Sten

    2014-01-01

    The GIS Readiness Survey 2014 is a follow-up to the corresponding survey that was carried out among public institutions in Denmark in 2009. The present survey thus provides an updated image of status and challenges in relation to the use of spatial information, the construction of the com- mon...

  5. Conducting online surveys

    NARCIS (Netherlands)

    Selm, M. van; Jankowski, N.W.

    2006-01-01

    The World Wide Web (WWW) is increasingly being used as a tool and platform for survey research. Two types of electronic or online surveys available for data collection are the email and Web based survey, and they constitute the focus of this paper. We address a multitude of issues researchers should

  6. A Subaru galaxy redshift survey: WFMOS survey

    International Nuclear Information System (INIS)

    Takada, M

    2008-01-01

    A planned galaxy redshift survey with the Subaru 8.2m telescope, the WFMOS survey, offers a unique opportunity for probing detailed properties of large-scale structure formation in the expanding universe by measuring clustering strength of galaxy distribution as a function of distance scale and redshift. In particular, the precise measurement of the galaxy power spectrum, combined with the cosmic microwave background experiments, allows us to obtain stringent constraints on or even determine absolute mass scales of the Big-Bang relic neutrinos as the neutrinos imprint characteristic scale- and redshift-dependent modifications onto the galaxy power spectrum shape. Here we describe the basic concept of how the galaxy clustering measurement can be used to explore the neutrino masses, with particular emphasis on advantages of the WFMOS survey over the existing low-redshift surveys such as SDSS

  7. Evaluating the longitudinal risk of social vigilance on atherosclerosis: study protocol for the North Texas Heart Study.

    Science.gov (United States)

    Ruiz, John M; Taylor, Daniel J; Uchino, Bert N; Smith, Timothy W; Allison, Matthew; Ahn, Chul; Johnson, Jillian J; Smyth, Joshua M

    2017-08-14

    Psychosocial factors are increasingly recognised as important determinants of cardiovascular disease risk. The North Texas Heart Study aims to understand the mechanisms responsible for this association with a focus on social vigilance (ie, scanning the environment for social threats). There is also growing interest in supplementing traditional methods (eg, survey assessment of psychosocial risk paired with cross-sectional and longitudinal health outcomes) with daily or repeated momentary assessment of psychosocial factors. However, there are relatively few longitudinal studies directly comparing these approaches with hard endpoints. The North Texas Heart Study proposes a longitudinal measurement burst design to examine psychosocial determinants of subclinical atherosclerosis. A sample of 300 healthy community participants, stratified by age and gender, will complete survey measures, as well as 2 days of ecological momentary assessment at baseline and at a 2-year follow-up. A range of psychosocial and behavioural factors, objective biomarkers, as well as carotid intima-media thickness (cIMT) will be assessed at both time points. Unadjusted and adjusted models will evaluate cross-sectional associations and determinants of change in the cIMT. The Institutional Review Board at the study coordinating institute (University of North Texas) has approved this study. Positive, negative or inconclusive primary and ancillary findings will be disseminated in scientific journals and conferences. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  8. Incorporation of integrative medicine education into undergraduate medical education: a longitudinal study

    Institute of Scientific and Technical Information of China (English)

    Saswati Mahapatra; Anjali Bhagra; Bisrat Fekadu; Zhuo Li; Brent A.Bauer; Dietlind L.Wahner-Roedler

    2017-01-01

    OBJECTIVE:Integrative medicine (IM) combines complementary medical approaches into conventional medicine and considers the whole person.We implemented a longitudinal IM short-course curriculum into our medical school education.This study aimed to evaluate the feasibility and effectiveness of the curriculum via knowledge and attitude surveys regarding IM among students.METHODS:A mandatory short IM curriculum across all years of medical school was created and taught by IM professionals and physician faculty members with expertise in integrative therapies.Graduating classes of 2015 and 2016 completed the same survey in their first and third years of medical school.Paired data analysis was done,and only students who completed surveys at both time points were included in final analyses.RESULTS:Of 52 students in each class,17 (33%) in the class of 2015 and 22 (42%) in the class of 2016 completed both surveys.After the IM curriculum,students' knowledge of and comfort with several IM therapies—biofeedback,mindfulness,and the use of St.John's wort—improved significantly.Students' personal health practices also improved,including better sleep,exercise,and stress management for the class of 2015.Students graduating in 2016 reported decreased alcohol use in their third year compared with their first year.CONCLUSION:It is feasible to incorporate IM education into undergraduate medical education,and this is associated with improvement in students' knowledge of IM and personal health practices.

  9. Cross-Sectional Analysis of Longitudinal Mediation Processes.

    Science.gov (United States)

    O'Laughlin, Kristine D; Martin, Monica J; Ferrer, Emilio

    2018-01-01

    Statistical mediation analysis can help to identify and explain the mechanisms behind psychological processes. Examining a set of variables for mediation effects is a ubiquitous process in the social sciences literature; however, despite evidence suggesting that cross-sectional data can misrepresent the mediation of longitudinal processes, cross-sectional analyses continue to be used in this manner. Alternative longitudinal mediation models, including those rooted in a structural equation modeling framework (cross-lagged panel, latent growth curve, and latent difference score models) are currently available and may provide a better representation of mediation processes for longitudinal data. The purpose of this paper is twofold: first, we provide a comparison of cross-sectional and longitudinal mediation models; second, we advocate using models to evaluate mediation effects that capture the temporal sequence of the process under study. Two separate empirical examples are presented to illustrate differences in the conclusions drawn from cross-sectional and longitudinal mediation analyses. Findings from these examples yielded substantial differences in interpretations between the cross-sectional and longitudinal mediation models considered here. Based on these observations, researchers should use caution when attempting to use cross-sectional data in place of longitudinal data for mediation analyses.

  10. Environmental Survey preliminary report

    Energy Technology Data Exchange (ETDEWEB)

    1988-04-01

    This report presents the preliminary findings from the first phase of the Environmental Survey of the United States Department of Energy (DOE) Sandia National Laboratories conducted August 17 through September 4, 1987. The objective of the Survey is to identify environmental problems and areas of environmental risk associated with Sandia National Laboratories-Albuquerque (SNLA). The Survey covers all environmental media and all areas of environmental regulation. It is being performed in accordance with the DOE Environmental Survey Manual. This phase of the Survey involves the review of existing site environmental data, observations of the operations carried on at SNLA, and interviews with site personnel. 85 refs., 49 figs., 48 tabs.

  11. Primer on Health Surveys

    Directory of Open Access Journals (Sweden)

    David L Nordstrom

    2012-06-01

    Full Text Available The aim of this paper is to introduce novice researchers to surveys as a method of data collection. It starts with the definition of a survey, its major purposes and types as well as changes in the goals surveys have helped to achieve over time. Advantages and disadvantages of surveys over population censuses and medical examinations are discussed. Approaches to questionnaire construction are introduced along with properties that questionnaires are evaluated for. Modes of administration, sample size issues, and data analysis approaches are also introduced. The primer is illustrated with examples of surveys conducted in different countries with various public health purposes.

  12. Pilot study protocol to inform a future longitudinal study of ageing using linked administrative data: Healthy AGeing in Scotland (HAGIS).

    Science.gov (United States)

    Douglas, Elaine; Rutherford, Alasdair; Bell, David

    2018-01-10

    Population ageing is a welcome testament to improvements in the social, economic and health circumstances over the life course. However, these successes necessitate that we understand more about the pathways of ageing to plan and cost our health and social care services, to support our ageing population to live healthier for longer and to make adequate provisions for retirement. Longitudinal studies of ageing facilitate such understanding in many countries around the world. Scotland presently does not have a longitudinal study of ageing, despite dramatic increases to its ageing population and its poor health record. Healthy AGeing in Scotland (HAGIS) constitutes the launch of Scotland's first comprehensive longitudinal study of ageing. A sample of 1000 people aged 50+ years will be invited to take part in a household social survey. The innovative sampling procedure used administrative data to identify eligible households. Anonymised survey responses will be linked to administrative data. Ethics approval was obtained from the host institution for the study design and from the Public Benefits and Privacy Panel for administrative data linkage. Anonymised survey data will be deposited with the UK Data Service. A subset of survey data, harmonised with other global ageing studies, will be available via the Gateway to Global Aging platform. These data will enable powerful cross-country comparisons across the social, economic and health domains that will be relevant for national and international research.Research publications from the HAGIS team will be disseminated through journal articles and national and international conferences. The findings will support current and future research and policy debate on ageing populations. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  13. Developing the online survey.

    Science.gov (United States)

    Gordon, Jeffry S; McNew, Ryan

    2008-12-01

    Institutions of higher education are now using Internet-based technology tools to conduct surveys for data collection. Research shows that the type and quality of responses one receives with online surveys are comparable with what one receives in paper-based surveys. Data collection can take place on Web-based surveys, e-mail-based surveys, and personal digital assistants/Smartphone devices. Web surveys can be subscription templates, software packages installed on one's own server, or created from scratch using Web programming development tools. All of these approaches have their advantages and disadvantages. The survey owner must make informed decisions as to the right technology to implement. The correct choice can save hours of work in sorting, organizing, and analyzing data.

  14. The Role of Microsimulation in Longitudinal Data Analysis

    Directory of Open Access Journals (Sweden)

    Douglas A. Wolf

    2001-12-01

    microsimulation also has the potential to contribute to longitudinal data analysis in several ways, including extending the range of outputs generated by a model, addressing several defective-data problems, and serving as a vehicle for missing-data imputation. This paper discusses microsimulation procedures suitable for several commonly-used statistical models applied to longitudinal data. It also addresses the unique role that can be played by microsimulation in longitudinal data analysis, and the problem of accounting for the several sources of variability associated with microsimulation procedures.

  15. A single hole tracer test to determine longitudinal dispersion

    International Nuclear Information System (INIS)

    Noy, D.J.; Holmes, D.C.

    1986-03-01

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

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

    Directory of Open Access Journals (Sweden)

    Mengling Liu

    2012-01-01

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

  17. Longitudinal Electron Bunch Diagnostics Using Coherent Transition Radiation

    CERN Document Server

    Mihalcea, Daniel; Happek, Uwe; Regis-Guy Piot, Philippe

    2005-01-01

    The longitudinal charge distribution of electron bunches in the Fermilab A0 photo-injector was determined by using the coherent transition radiation produced by electrons passing through a thin metallic foil. The auto-correlation of the transition radiation signal was measured with a Michelson type interferometer. The response function of the interferometer was determined from measured and simulated power spectra for low electron bunch charge and maximum longitudinal compression. Kramers-Kroning technique was used to determine longitudinal charge distribution. Measurements were performed for electron bunch lengths in the range from 0.3 to 2 ps (rms).

  18. Signal processing for longitudinal parameters of the Tevatron beam

    International Nuclear Information System (INIS)

    Pordes, S.; Crisp, J.; Fellenz, B.; Flora, R.; Para, A.; Tollestrup, A.V.

    2005-01-01

    We describe the system known as the Tevatron SBD [1] which is used to provide information on the longitudinal parameters of coalesced beam bunches in the Tevatron. The system has been upgraded over the past year with a new digitizer and improved software. The quantities provided for each proton and antiproton bunch include the intensity, the longitudinal bunch profile, the timing of the bunch with respect to the low-level RF, the momentum spread and the longitudinal emittance. The system is capable of 2 Hz operation and is run at 1 Hz

  19. The Fundamentals of Longitudinal Research: An Overview

    Directory of Open Access Journals (Sweden)

    Rajulton, Fernando

    2001-01-01

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

  20. Regression analysis of sparse asynchronous longitudinal data.

    Science.gov (United States)

    Cao, Hongyuan; Zeng, Donglin; Fine, Jason P

    2015-09-01

    We consider estimation of regression models for sparse asynchronous longitudinal observations, where time-dependent responses and covariates are observed intermittently within subjects. Unlike with synchronous data, where the response and covariates are observed at the same time point, with asynchronous data, the observation times are mismatched. Simple kernel-weighted estimating equations are proposed for generalized linear models with either time invariant or time-dependent coefficients under smoothness assumptions for the covariate processes which are similar to those for synchronous data. For models with either time invariant or time-dependent coefficients, the estimators are consistent and asymptotically normal but converge at slower rates than those achieved with synchronous data. Simulation studies evidence that the methods perform well with realistic sample sizes and may be superior to a naive application of methods for synchronous data based on an ad hoc last value carried forward approach. The practical utility of the methods is illustrated on data from a study on human immunodeficiency virus.

  1. Analysis of critically refracted longitudinal waves

    Energy Technology Data Exchange (ETDEWEB)

    Pei, Ning, E-mail: npei@iastate.edu; Bond, Leonard J., E-mail: npei@iastate.edu [Center for Nondestructive Evaluation, Iowa State University, Ames, IA 50011 (United States)

    2015-03-31

    Fabrication processes, such as, welding, forging, and rolling can induce residual stresses in metals that will impact product performance and phenomena such as cracking and corrosion. To better manage residual stress tools are needed to map their distribution. The critically refracted ultrasonic longitudinal (LCR) wave is one such approach that has been used for residual stress characterization. It has been shown to be sensitive to stress and less sensitive to the effects of the texture of the material. Although the LCR wave is increasingly widely applied, the factors that influence the formation of the LCR beam are seldom discussed. This paper reports a numerical model used to investigate the transducers' parameters that can contribute to the directionality of the LCR wave and hence enable performance optimization when used for industrial applications. An orthogonal test method is used to study the transducer parameters which influence the LCR wave beams. This method provides a design tool that can be used to study and optimize multiple parameter experiments and it can identify which parameter or parameters are of most significance. The simulation of the sound field in a 2-D 'water-steel' model is obtained using a Spatial Fourier Analysis method. The effects of incident angle, standoff, the aperture and the center frequency of the transducer were studied. Results show that the aperture of the transducer, the center frequency and the incident angle are the most important factors in controlling the directivity of the resulting LCR wave fields.

  2. Longitudinal morphometric MRI study of Alzheimer's disease

    International Nuclear Information System (INIS)

    Ogomori, Koji; Takano, Koichi; Kuwabara, Yasuo; Nakano, Seigo; Nawata, Hideyuki; Yano, Rika; Nishimura, Ryoji; Takita, Masashi

    2009-01-01

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

  3. Longitudinal growth changes in subjects with deepbite.

    Science.gov (United States)

    Baccetti, Tiziano; Franchi, Lorenzo; McNamara, James A

    2011-08-01

    This study was a cephalometric evaluation of the growth changes in untreated subjects with deepbite at 4 time points during their developmental ages (from the early mixed dentition to the permanent dentition, and from the prepubertal phase to young adulthood). A sample of 29 subjects with deepbite (overbite >4.5 mm) was followed longitudinally from about 9 through about 18 years of age. Dentofacial changes at 4 times, defined by the cervical vertebral maturation method, were analyzed on lateral cephalograms. Nonparametric statistical analysis was used for comparisons. Overbite improved on average by 1.3 mm between the first and last measurements; it worsened significantly during the prepubertal period, but it improved significantly at the pubertal growth spurt. From the prepubertal ages through young adulthood, overbite improved in 83% of the subjects and self-corrected in 62% of the subjects. Improvements in overbite were related to the initial amount of maxillary incisor proclination. The significant improvement in overbite during the adolescent growth spurt depended on the amount of vertical growth of the mandibular ramus and the eruption of the mandibular molars. Subjects with deepbite showed worsened occlusal conditions during the prepubertal and mixed dentition phases, but had significant improvements thereafter. Improvements in overbite cannot be predicted on the basis of skeletal vertical relationships. These results provide useful indications for appropriate orthodontic treatment timing for an increased overbite. Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  4. The association between modifiable well-being risks and productivity: a longitudinal study in pooled employer sample.

    Science.gov (United States)

    Shi, Yuyan; Sears, Lindsay E; Coberley, Carter R; Pope, James E

    2013-04-01

    To examine the longitudinal relationship between modifiable well-being risks and productivity. A total of 19,121 employees from five employers participated in baseline and follow-up well-being assessment surveys. Multivariate regressions assessed whether changes in absenteeism, presenteeism, and job performance were associated with changes in 19 modifiable well-being risks. Over time, a 5% reduction in total count of well-being risks was significantly associated with 0.74% decrease in absenteeism, 2.38% decrease in presenteeism, and 0.24% increase in performance. High blood pressure, recurring pain, unhealthy diet, inadequate exercise, poor emotional health, poor supervisor relationship, not utilizing strengths doing job, and organization unsupportive of well-being had greater independent contributions in explaining productivity impairment. The often-ignored well-being risks such as work-related and financial health risks provided incremental explanation of longitudinal productivity variations beyond traditional measures of health-related risks.

  5. Transformation of QSPA plasma streams in longitudinal magnetic field

    International Nuclear Information System (INIS)

    Makhlaj, V.A.; Bandura, A.N.; Chebotarev, V.V.; Kulik, N.V.; Wuerz, H.

    2002-01-01

    The main aim of this work is analysis of efficiency of QSPA powerful plasma streams transportation in longitudinal magnetic field in dependence on operational mode of accelerator and plasma stream parameters

  6. Prediction of the development of reading comprehension: a longitudinal study

    NARCIS (Netherlands)

    Verhoeven, L.T.W.; Leeuwe, J.F.J. van

    2008-01-01

    Specific effects of word decoding, vocabulary and listening comprehension abilities on the development of reading comprehension were longitudinally examined for a representative sample of 2143 Dutch children throughout the elementary school period. An attempt was made to test two theoretical

  7. Horizontal-Longitudinal Correlations of Acoustic Field in Deep Water

    International Nuclear Information System (INIS)

    Li Jun; Li Zheng-Lin; Ren Yun; Li Wen; Zhang Ren-He

    2015-01-01

    The horizontal-longitudinal correlations of the acoustic field in deep water are investigated based on the experimental data obtained in the South China Sea. It is shown that the horizontal-longitudinal correlation coefficients in the convergence zone are high, and the correlation length is consistent with the convergence zone width, which depends on the receiver depth and range. The horizontal-longitudinal correlation coefficients in the convergence zone also have a division structure for the deeper receiver. The signals from the second part of the convergence zone are still correlated with the reference signal in the first part. The horizontal-longitudinal correlation coefficients in the shadow zone are lower than that in the convergence zone, and the correlation length in the shadow zone is also much shorter than that in the convergence zone. The numerical simulation results by using the normal modes theory are qualitatively consistent with the experimental results. (paper)

  8. Dynamics of a longitudinal current during a magnetic storm

    International Nuclear Information System (INIS)

    Dolginov, S.Sh.; Zhuzgov, L.N.; Kosacheva, V.P.; Strunnikova, L.N.; Tyurmina, L.O.; Sharova, V.A.; Shkol'nikova, S.I.

    1984-01-01

    Results, investigating a spatial distribution and the structure of longitudinal currents during a magnetic storm at 18-19.09.81, are presented. It is shown that during the main phase of the storm the large-scale current system expands to the equator, and current density increases. Inside the current layer and to the pole of it there appears intensive small scale longitudinal l currents. During magnetic storm restopation phase the current system segregates into several pairs of opposite directed currents. During further decreasing of geomagnetic activity the large-scale current system is restored+ and its center is shifted to the pole, longitudinal current density being decreased. The invariant width of longitudinal currents is decreased, while the magnitude, Dsub(st), being increased, that is connected to the displacement of an auroral oval to the equator

  9. A New Kicker for the TLS Longitudinal Feedback System

    CERN Document Server

    Lau, Wai-Keung; Dehler, Micha; Hsu, Kuo-Tung; Hsu, San-Yuang; Jung Chou Ping; Wei Chen, Cheng; Yang Chen Huan; Yang Tze Te

    2005-01-01

    A new longitudinal kicker that is modified from the Swiss Light Source (SLS) design to fit into the TLS storage ring. It will be served as the actuator in the longitudinal multi-bunch feedback control loop. Beam coupling impedance has been calculated by Gdfidl with a PC cluster. Previous to the installation of this new kicker, bench measurement has been performed in the laboratory to characterize this new kicker. The experimental setups for bandwidth and coaxial wire measurement of longitudinal coupling impedance and their corresponding test results will be reported. As a cross check, bead-pull measurement has also been done to verify the beam coupling measurement by coaxial wire method at the kicker center frequency. Longitudinal field profile of the accelerating mode along the beam path has also been mapped. High order cavity modes of the kicker have also been observed and their effects on the beam are evaluated.

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

    International Nuclear Information System (INIS)

    Boroun, G.R.

    2010-01-01

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

  11. Generalized latent variable modeling multilevel, longitudinal, and structural equation models

    CERN Document Server

    Skrondal, Anders; Rabe-Hesketh, Sophia

    2004-01-01

    This book unifies and extends latent variable models, including multilevel or generalized linear mixed models, longitudinal or panel models, item response or factor models, latent class or finite mixture models, and structural equation models.

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

    Science.gov (United States)

    Raffa, Jesse D; Dubin, Joel A

    2015-09-01

    Multiple longitudinal responses are often collected as a means to capture relevant features of the true outcome of interest, which is often hidden and not directly measurable. We outline an approach which models these multivariate longitudinal responses as generated from a hidden disease process. We propose a class of models which uses a hidden Markov model with separate but correlated random effects between multiple longitudinal responses. This approach was motivated by a smoking cessation clinical trial, where a bivariate longitudinal response involving both a continuous and a binomial response was collected for each participant to monitor smoking behavior. A Bayesian method using Markov chain Monte Carlo is used. Comparison of separate univariate response models to the bivariate response models was undertaken. Our methods are demonstrated on the smoking cessation clinical trial dataset, and properties of our approach are examined through extensive simulation studies. © 2015, The International Biometric Society.

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

    Directory of Open Access Journals (Sweden)

    Chantel D. Mayo

    2017-01-01

    Conclusion: 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.

  14. Acquisition patterns of financial products : A longitudinal investigation

    NARCIS (Netherlands)

    Paas, Leonard J.; Bijmolt, Tammo H. A.; Vermunt, Jeroen K.

    Acquisition pattern analysis investigates orders in which households acquire products. Extant empirical studies employ cross-sectional data, providing limited insight into acquisition orders and no insight into timing of product acquisitions. We use an extensive longitudinal database for studying

  15. Generalized empirical likelihood methods for analyzing longitudinal data

    KAUST Repository

    Wang, S.; Qian, L.; Carroll, R. J.

    2010-01-01

    Efficient estimation of parameters is a major objective in analyzing longitudinal data. We propose two generalized empirical likelihood based methods that take into consideration within-subject correlations. A nonparametric version of the Wilks

  16. Latitudinal and longitudinal variation in aerosol characteristics from ...

    Indian Academy of Sciences (India)

    The physical and chemical properties of aerosols are strong ... Keywords. Aerosol optical characteristics; latitudinal and longitudinal variations; Bay of Bengal; Arabian Sea; pre- ...... of global sources of atmospheric soil dust identified with the ...

  17. Age and Educational Inequalities in Smoking Cessation Due to Three Population-Level Tobacco Control Interventions: Findings from the International Tobacco Control (ITC) Netherlands Survey

    Science.gov (United States)

    Nagelhout, Gera E.; Crone, Matty R.; van den Putte, Bas; Willemsen, Marc C.; Fong, Geoffrey T.; de Vries, Hein

    2013-01-01

    This study aimed to examine age and educational inequalities in smoking cessation due to the implementation of a tobacco tax increase, smoke-free legislation and a cessation campaign. Longitudinal data from 962 smokers aged 15 years and older were used from three survey waves of the International Tobacco Control (ITC) Netherlands Survey. The 2008…

  18. The relative size of measurement error and attrition error in a panel survey. Comparing them with a new multi-trait multi-method model

    NARCIS (Netherlands)

    Lugtig, Peter

    2017-01-01

    This paper proposes a method to simultaneously estimate both measurement and nonresponse errors for attitudinal and behavioural questions in a longitudinal survey. The method uses a Multi-Trait Multi-Method (MTMM) approach, which is commonly used to estimate the reliability and validity of survey

  19. Web survey methodology

    CERN Document Server

    Callegaro, Mario; Vehovar, Asja

    2015-01-01

    Web Survey Methodology guides the reader through the past fifteen years of research in web survey methodology. It both provides practical guidance on the latest techniques for collecting valid and reliable data and offers a comprehensive overview of research issues. Core topics from preparation to questionnaire design, recruitment testing to analysis and survey software are all covered in a systematic and insightful way. The reader will be exposed to key concepts and key findings in the literature, covering measurement, non-response, adjustments, paradata, and cost issues. The book also discusses the hottest research topics in survey research today, such as internet panels, virtual interviewing, mobile surveys and the integration with passive measurements, e-social sciences, mixed modes and business intelligence. The book is intended for students, practitioners, and researchers in fields such as survey and market research, psychological research, official statistics and customer satisfaction research.

  20. Dynamics of heavy ion beams during longitudinal compression

    International Nuclear Information System (INIS)

    Ho, D.D.M.; Bangerter, R.O.; Lee, E.P.; Brandon, S.; Mark, J.W.K.

    1987-01-01

    Heavy ion beams with initially uniform line charge density can be compressed longitudinally by an order of magnitude in such a way that the compressed beam has uniform line charge density and velocity-tilt profiles. There are no envelope mismatch oscillations during compression. Although the transverse temperature varies along the beam and also varies with time, no substantial longitudinal and transverse emittance growth has been observed. Scaling laws for beam radius and transport system parameters are given

  1. Simultaneous maximum a posteriori longitudinal PET image reconstruction

    Science.gov (United States)

    Ellis, Sam; Reader, Andrew J.

    2017-09-01

    Positron emission tomography (PET) is frequently used to monitor functional changes that occur over extended time scales, for example in longitudinal oncology PET protocols that include routine clinical follow-up scans to assess the efficacy of a course of treatment. In these contexts PET datasets are currently reconstructed into images using single-dataset reconstruction methods. Inspired by recently proposed joint PET-MR reconstruction methods, we propose to reconstruct longitudinal datasets simultaneously by using a joint penalty term in order to exploit the high degree of similarity between longitudinal images. We achieved this by penalising voxel-wise differences between pairs of longitudinal PET images in a one-step-late maximum a posteriori (MAP) fashion, resulting in the MAP simultaneous longitudinal reconstruction (SLR) method. The proposed method reduced reconstruction errors and visually improved images relative to standard maximum likelihood expectation-maximisation (ML-EM) in simulated 2D longitudinal brain tumour scans. In reconstructions of split real 3D data with inserted simulated tumours, noise across images reconstructed with MAP-SLR was reduced to levels equivalent to doubling the number of detected counts when using ML-EM. Furthermore, quantification of tumour activities was largely preserved over a variety of longitudinal tumour changes, including changes in size and activity, with larger changes inducing larger biases relative to standard ML-EM reconstructions. Similar improvements were observed for a range of counts levels, demonstrating the robustness of the method when used with a single penalty strength. The results suggest that longitudinal regularisation is a simple but effective method of improving reconstructed PET images without using resolution degrading priors.

  2. Longitudinal permittivity of a toroidal plasma near rational surfaces

    International Nuclear Information System (INIS)

    Nekrasov, F.M.

    1990-01-01

    A quite simple analytical formula for longitudinal permittivity, suitable for numerical processing on a computer, is determined. On the basis of a Fourier representation a poloidal angle a compact expression for the imaginary part of longitudinal permittivity near rational surfaces (m+nq=0) at an arbitrary relation between the bounce frequency and excited wave frequency is determined. A strongly magnetized collisionless plasma in the weak toroidality approximation is considered

  3. Longitudinal research and data collection in primary care.

    Science.gov (United States)

    van Weel, Chris

    2005-01-01

    This article reviews examples of and experience with longitudinal research in family medicine. The objective is to use this empirical information to formulate recommendations for improving longitudinal research. The article discusses 3 longitudinal studies from the Nijmegen academic family practice research network: 1 on the prognosis of depression and 1 each on the prognosis of and outcomes of care for type 2 diabetes mellitus. The Nijmegen network has recorded all episodes of morbidity encountered in Dutch family medicine since 1971 in a stable practice population. This network's experience is evaluated to identify lessons that may help other practice-based research networks (PBRNs) in pursuing longitudinal research. In terms of external conditions (conditions related to the general setting), the stability of a population and a high level of continuity of care substantially enhance the ability to perform longitudinal research. In terms of internal conditions (conditions related to the PBRN), motivation of family physicians and their staff to conduct ongoing data collection, and their ownership of the data are key for success. Other critical internal conditions include standardization of data; collection of data by clinician-friendly means; training of family physicians and their staff in data collection, as well as meetings for discussion of this task; provision of feedback to practices on the research findings; use of standard procedures to promote adherence to data collection; availability of facilities for regular measurement of patients' health status or chart review; and use of mechanisms for tracking patients who leave the practice area. Insight from existing experience suggests that longitudinal research can be enhanced in PBRNs. The best way forward is to build longitudinal data collection by drawing on lessons from successful studies. Primary care research policy should advocate for a role of longitudinal research and stimulate its development in PBRNs

  4. Causal mediation analysis for longitudinal data with exogenous exposure

    OpenAIRE

    Bind, M.-A. C.; Vanderweele, T. J.; Coull, B. A.; Schwartz, J. D.

    2015-01-01

    Mediation analysis is a valuable approach to examine pathways in epidemiological research. Prospective cohort studies are often conducted to study biological mechanisms and often collect longitudinal measurements on each participant. Mediation formulae for longitudinal data have been developed. Here, we formalize the natural direct and indirect effects using a causal framework with potential outcomes that allows for an interaction between the exposure and the mediator. To allow different type...

  5. Statistical methods for longitudinal data with agricultural applications

    DEFF Research Database (Denmark)

    Anantharama Ankinakatte, Smitha

    The PhD study focuses on modeling two kings of longitudinal data arising in agricultural applications: continuous time series data and discrete longitudinal data. Firstly, two statistical methods, neural networks and generalized additive models, are applied to predict masistis using multivariate...... algorithm. This was found to compare favourably with the algorithm implemented in the well-known Beagle software. Finally, an R package to apply APFA models developed as part of the PhD project is described...

  6. Transverse and longitudinal angular momenta of light

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-08-26

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

  7. Magnetic characterisation of longitudinal thin film media

    International Nuclear Information System (INIS)

    Dova, P.

    1998-09-01

    Magnetic characterisation techniques, as applied to longitudinal thin film media, have been investigated. These included the study of the differentials of the remanence curves, the delta-M plot and the examination of the critical volumes. Several thin film structures, which are currently used or are being considered for future media applications, have been examined using these techniques. Most of the films were Co-alloys with the exception of a set of Barium ferrite films. Both monolayer and multilayer structures were studied. It was found that the study of activation volumes provides a better insight into the reversal mechanisms of magnetic media, especially in the case of complex structures such as multilayer films and films with bicrystal microstructure. Furthermore, an evaluation study of different methods of determining critical volumes showed that the method using time dependence measurements and the micromagnetic approach is the most appropriate. The magnetic characteristics of the thin film media under investigation were correlated with their microstructure and, where possible, with their noise performance. Magnetic force microscopy was also used for acquiring quasi-domain images in the ac-demagnetised state. It was found that in all Co-alloy films the dominant intergranular coupling is magnetising in nature, the level of which is governed by the Cr content in the magnetic layer. In the case of laminated media it was found that when non-magnetic spacers are used, the nature of the interlayer coupling depends on the spacer thickness. In double layer structures with no spacer, the top layer replicates the crystallographic texture of the bottom layer, and the overall film properties are a combination of the two layers. In bicrystal films the coupling is determined by the Cr segregation in the grain boundaries. Furthermore, the presence of stacking faults in bicrystal films deteriorates their thermal stability, but can be prevented by improving the epitaxial

  8. Longitudinal Association of Dementia and Depression.

    Science.gov (United States)

    Snowden, Mark B; Atkins, David C; Steinman, Lesley E; Bell, Janice F; Bryant, Lucinda L; Copeland, Catherine; Fitzpatrick, Annette L

    2015-09-01

    Depression is an important precursor to dementia, but less is known about the role dementia plays in altering the course of depression. We examined whether depression prevalence, incidence, and severity are higher in those with dementia versus those with mild cognitive impairment (MCI), or normal cognition. Prospective cohort study using the longitudinal Uniform Data Set of the National Alzheimer's Coordinating Center (2005-2013). 34 Alzheimer Disease research centers. 27,776 subjects with dementia, MCI, or normal cognition. Depression status was determined by a clinical diagnosis of depression within the prior 2 years and by a Geriatric Depression Scale-Short Form score >5. Rates of depression were significantly higher in subjects with MCI and dementia compared with those with normal cognition at index visit. Controlling for demographics and common chronic conditions, logistic regression analysis revealed elevated depression in those with MCI (OR: 2.40 [95% CI: 2.25, 2.56]) or dementia (OR: 2.64 [95% CI: 2.43, 2.86]) relative to those with normal cognition. In the subjects without depression at the index visit (N = 18,842), those with MCI and dementia had higher probabilities of depression diagnosis 2 years post index visit than those with normal cognition: MCI = 21.7%, dementia = 24.7%, normal cognition = 10.5%. MCI and dementia were associated with significantly higher rates of depression in concurrent as well as prospective analyses. These findings suggest that efforts to effectively engage and treat older adults with dementia will need also to address co-occurring depression. Copyright © 2015 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.

  9. Longitudinal and bulk viscosities of Lennard-Jones fluids

    Science.gov (United States)

    Tankeshwar, K.; Pathak, K. N.; Ranganathan, S.

    1996-12-01

    Expressions for the longitudinal and bulk viscosities have been derived using Green Kubo formulae involving the time integral of the longitudinal and bulk stress autocorrelation functions. The time evolution of stress autocorrelation functions are determined using the Mori formalism and a memory function which is obtained from the Mori equation of motion. The memory function is of hyperbolic secant form and involves two parameters which are related to the microscopic sum rules of the respective autocorrelation function. We have derived expressions for the zeroth-, second-and fourth- order sum rules of the longitudinal and bulk stress autocorrelation functions. These involve static correlation functions up to four particles. The final expressions for these have been put in a form suitable for numerical calculations using low- order decoupling approximations. The numerical results have been obtained for the sum rules of longitudinal and bulk stress autocorrelation functions. These have been used to calculate the longitudinal and bulk viscosities and time evolution of the longitudinal stress autocorrelation function of the Lennard-Jones fluids over wide ranges of densities and temperatures. We have compared our results with the available computer simulation data and found reasonable agreement.

  10. Longitudinal beam compression for heavy-ion inertial fusion

    International Nuclear Information System (INIS)

    Ho, D.D.M.; Brandon, S.T.

    1991-01-01

    A scheme is described for compressing a heavy-ion beam longitudinally in such a way that the compressed pulse has uniform line-charge density and longitudinal momentum. Attaining these conditions will be important in the final focusing of a beam on a small fuel capsule in an inertial confinement fusion reactor. The longitudinal dynamics can be approximately described by a one-dimensional (1-D) fluid model for charged particles. Recognizing the similarity between the 1-D charged particle equations of motion and the 1-D equations for ideal-gas flow permits us to calculate the evolution of the line-charge density and velocity profile using self-similar solutions and the method of characteristics, developed for unsteady supersonic gas dynamics, for different regions along the beam. Simple physical arguments show that although the longitudinal and transverse temperatures vary along the beam following the adiabatic laws, no substantial longitudinal and transverse emittance growth is to be expected. Particle-in-cell simulations confirm all the physical arguments. The compressed beam has negligible longitudinal momentum spread and can therefore avoid chromatic aberrations in final focus. (author) 24 refs., 5 figs., 1 tab

  11. Longitudinal changes in white matter microstructure after heavy cannabis use

    Directory of Open Access Journals (Sweden)

    Mary P. Becker

    2015-12-01

    Full Text Available Diffusion tensor imaging (DTI studies of cannabis users report alterations in brain white matter microstructure, primarily based on cross-sectional research, and etiology of the alterations remains unclear. We report findings from longitudinal voxelwise analyses of DTI data collected at baseline and at a 2-year follow-up on 23 young adult (18–20 years old at baseline regular cannabis users and 23 age-, sex-, and IQ-matched non-using controls with limited substance use histories. Onset of cannabis use was prior to age 17. Cannabis users displayed reduced longitudinal growth in fractional anisotropy in the central and parietal regions of the right and left superior longitudinal fasciculus, in white matter adjacent to the left superior frontal gyrus, in the left corticospinal tract, and in the right anterior thalamic radiation lateral to the genu of the corpus callosum, along with less longitudinal reduction of radial diffusion in the right central/posterior superior longitudinal fasciculus, corticospinal tract, and posterior cingulum. Greater amounts of cannabis use were correlated with reduced longitudinal growth in FA as was relatively impaired performance on a measure of verbal learning. These findings suggest that continued heavy cannabis use during adolescence and young adulthood alters ongoing development of white matter microstructure, contributing to functional impairment.

  12. Longitudinal drop-out and weighting against its bias

    Directory of Open Access Journals (Sweden)

    Steffen C. E. Schmidt

    2017-12-01

    Full Text Available Abstract Background The bias caused by drop-out is an important factor in large population-based epidemiological studies. Many studies account for it by weighting their longitudinal data, but to date there is no detailed final approach for how to conduct these weights. Methods In this study we describe the observed longitudinal bias and a three-step longitudinal weighting approach used for the longitudinal data in the MoMo baseline (N = 4528, 4–17 years and wave 1 study with 2807 (62% participants between 2003 and 2012. Results The most meaningful drop-out predictors were socioeconomic status of the household, socioeconomic characteristics of the mother and daily TV usage. Weighting reduced the bias between the longitudinal participants and the baseline sample, and also increased variance by 5% to 35% with a final weighting efficiency of 41.67%. Conclusions We conclude that a weighting procedure is important to reduce longitudinal bias in health-oriented epidemiological studies and suggest identifying the most influencing variables in the first step, then use logistic regression modeling to calculate the inverse of the probability of participation in the second step, and finally trim and standardize the weights in the third step.

  13. Modelling, simulation and applications of longitudinal train dynamics

    Science.gov (United States)

    Cole, Colin; Spiryagin, Maksym; Wu, Qing; Sun, Yan Quan

    2017-10-01

    Significant developments in longitudinal train simulation and an overview of the approaches to train models and modelling vehicle force inputs are firstly presented. The most important modelling task, that of the wagon connection, consisting of energy absorption devices such as draft gears and buffers, draw gear stiffness, coupler slack and structural stiffness is then presented. Detailed attention is given to the modelling approaches for friction wedge damped and polymer draft gears. A significant issue in longitudinal train dynamics is the modelling and calculation of the input forces - the co-dimensional problem. The need to push traction performances higher has led to research and improvement in the accuracy of traction modelling which is discussed. A co-simulation method that combines longitudinal train simulation, locomotive traction control and locomotive vehicle dynamics is presented. The modelling of other forces, braking propulsion resistance, curve drag and grade forces are also discussed. As extensions to conventional longitudinal train dynamics, lateral forces and coupler impacts are examined in regards to interaction with wagon lateral and vertical dynamics. Various applications of longitudinal train dynamics are then presented. As an alternative to the tradition single wagon mass approach to longitudinal train dynamics, an example incorporating fully detailed wagon dynamics is presented for a crash analysis problem. Further applications of starting traction, air braking, distributed power, energy analysis and tippler operation are also presented.

  14. The transition from longitudinal to perpendicular recording

    International Nuclear Information System (INIS)

    Richter, H J

    2007-01-01

    After more than 30 years of research, hard disk drives using perpendicular recording are finally commercially available. This review is a follow-up of a review written in 1999 and addresses the basic physics of perpendicular recording with special emphasis on the read and the write process and the magnetic aspects of the recording media. The paper also surveys various technical difficulties which prevented an earlier implementation of perpendicular recording. The paper closes with a short overview of alternative technologies that allow even higher storage densities. (topical review)

  15. Aerial radiation survey

    International Nuclear Information System (INIS)

    Pradeep Kumar, K.S.

    1998-01-01

    Aerial gamma spectrometry surveys are the most effective, comprehensive and preferred tool to delimit the large area surface contamination in a radiological emergency either due to a nuclear accident or following a nuclear strike. The airborne survey apart from providing rapid and economical evaluation of ground contamination over large areas due to larger ground clearance and higher speed, is the only technique to overcome difficulties posed by ground surveys of inaccessible region. The aerial survey technique can also be used for searching of lost radioactive sources, tracking of radioactive plume and generation of background data on the Emergency Planning Zone (EPZ) of nuclear installations

  16. Survey of photovoltaic systems

    Energy Technology Data Exchange (ETDEWEB)

    1979-08-01

    In developing this survey of photovoltaic systems, the University of Alabama in Huntsville assembled a task team to perform an extensive telephone survey of all known photovoltaic manufacturers. Three US companies accounted for 77% of the total domestic sales in 1978. They are Solarex Corporation, Solar Power Croporation, and ARCO Solar, Inc. This survey of solar photovoltaic (P/V) manufacturers and suppliers consists of three parts: a catalog of suppliers arranged alphabetically, data sheets on specific products, and typical operating, installation, or maintenance instructions and procedures. This report does not recommend or endorse any company product or information presented within as the results of this survey.

  17. Management Satisfaction Survey

    Data.gov (United States)

    Office of Personnel Management — The Chief Human Capital Officers' Managers' Satisfaction Survey asks managers to rate their perception of workforce planning, interaction with and levels of support...

  18. Resilience Mediates the Longitudinal Relationships Between Social Support and Mental Health Outcomes in Multiple Sclerosis.

    Science.gov (United States)

    Koelmel, Emily; Hughes, Abbey J; Alschuler, Kevin N; Ehde, Dawn M

    2017-06-01

    To investigate the longitudinal relationships between social support and subsequent mental health outcomes in individuals with multiple sclerosis (MS), and to examine resilience as a mediator between social support and subsequent mental health outcomes in this population. Observational, longitudinal cohort study. Participants were assessed at 4 time points over 12 months in the context of a previously reported randomized controlled trial. Telephone-based measures administered to community-based participants. Individuals (N=163) with MS and 1 or more of the following symptoms: depression, fatigue, and pain. Not applicable. Mental health outcomes included (1) depressive symptomatology, assessed using the Patient Health Questionnaire-9; (2) anxious symptomatology, assessed using the short form of the Emotional Distress-Anxiety Scale from the Patient-Reported Outcomes Measurement Information System; and (3) general mental health status, assessed using the Mental Component Summary score from the Short Form-8 Health Survey. Resilience was assessed using the Connor-Davidson Resilience Scale. At any given time, social support from significant others, family members, and friends was significantly associated with subsequent mental health outcomes for all 3 measures assessed (all P values social support significantly mediated the relationships between social support and subsequent mental health outcomes. After controlling for resilience, most of the direct relationships between social support and mental health outcomes were no longer significant. There are significant longitudinal relationships between social support, resilience, and mental health outcomes for people with MS. Given the mediating role of resilience in supporting better mental health outcomes, future clinical research and practice may benefit from an emphasis on resilience-focused psychological interventions. Copyright © 2016 American Congress of Rehabilitation Medicine. All rights reserved.

  19. Longitudinal Andhra Pradesh Eye Disease Study: rationale, study design and research methodology.

    Science.gov (United States)

    Khanna, Rohit C; Murthy, Gudlavalleti Vs; Marmamula, Srinivas; Mettla, Asha Latha; Giridhar, Pyda; Banerjee, Seema; Shekhar, Konegari; Chakrabarti, Subhabrata; Gilbert, Clare; Rao, Gullapalli N

    2016-03-01

    The rationale, objectives, study design and procedures for the longitudinal Andhra Pradesh Eye Disease Study are described. A longitudinal cohort study was carried out. Participants include surviving cohort from the rural component of Andhra Pradesh Eye Disease Study. During 1996-2000, Andhra Pradesh Eye Disease Survey was conducted in three rural (n = 7771) and one urban (n = 2522) areas (now called Andhra Pradesh Eye Disease Study 1). In 2009-2010, a feasibility exercise (Andhra Pradesh Eye Disease Study 2) for a longitudinal study (Andhra Pradesh Eye Disease Study 3) was undertaken in the rural clusters only, as urban clusters no longer existed. In Andhra Pradesh Eye Disease Study 3, a detailed interview will be carried out to collect data on sociodemographic factors, ocular and systemic history, risk factors, visual function, knowledge of eye diseases and barriers to accessing services. All participants will also undergo a comprehensive eye examination including photography of lens, optic disc and retina, Optic Coherence Tomography of the posterior segment, anthropometry, blood pressure and frailty measures. Measures include estimates of the incidence of visual impairment and age-related eye disease (lens opacities, glaucoma and age-related macular degeneration) and the progression of eye disease (lens opacities and myopia) and associated risk factors. Of the 7771 respondents examined in rural areas in Andhra Pradesh Eye Disease Study 1, 5447 (70.1%) participants were traced in Andhra Pradesh Eye Disease Study 2. These participants will be re-examined. Andhra Pradesh Eye Disease Study 3 will provide data on the incidence and progression of visual impairment and major eye diseases and their associated risk factors in India. The study will provide further evidence to aid planning eye care services. © 2015 Royal Australian and New Zealand College of Ophthalmologists.

  20. Investigating strengths and deficits to increase work engagement: A longitudinal study in the mining industry

    Directory of Open Access Journals (Sweden)

    Pule Mphahlele

    2018-02-01

    Full Text Available Orientation: The motivational process of the Job Demands-Resources (JD-R model indicates that job resources are the main predictors of work engagement. Previous research has found that the two job resources perceived organisational support (POS for strengths use and POS for deficit correction are also positively related to work engagement. However, the causal relationships between these variables have not been investigated longitudinally. Research purpose: To determine if POS for strengths use and POS for deficit correction are significant predictors of work engagement over time. Motivation for the study: In the literature, empirical evidence on the longitudinal relationships between work engagement and specific job resources, namely POS for strengths use and POS for deficit correction, is limited. Research design, approach and method: A longitudinal design was employed in this study. The first wave elicited a total of 376 responses, while the second wave had a total sample size of 79. A web-based survey was used to measure the constructs and to gather data at both points in time. Structural equation modelling was used to investigate the hypotheses. Main findings: The results indicated that both POS for strengths use and POS for deficit correction are positively related to work engagement in the short term. However, only POS for deficit correction significantly predicted work engagement over time. Practical and managerial implications: The results provide valuable insights to organisations by providing knowledge regarding which approach influences work engagement levels of their employees in the short and long term. Contribution or value-add: The study contributes to the limited research on what job resources predict work engagement over time.