WorldWideScience

Sample records for high dropout rate

  1. Authoritative school climate and high school dropout rates.

    Science.gov (United States)

    Jia, Yuane; Konold, Timothy R; Cornell, Dewey

    2016-06-01

    This study tested the association between school-wide measures of an authoritative school climate and high school dropout rates in a statewide sample of 315 high schools. Regression models at the school level of analysis used teacher and student measures of disciplinary structure, student support, and academic expectations to predict overall high school dropout rates. Analyses controlled for school demographics of school enrollment size, percentage of low-income students, percentage of minority students, and urbanicity. Consistent with authoritative school climate theory, moderation analyses found that when students perceive their teachers as supportive, high academic expectations are associated with lower dropout rates. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  2. Authoritative School Climate and High School Dropout Rates

    Science.gov (United States)

    Jia, Yuane; Konold, Timothy R.; Cornell, Dewey

    2016-01-01

    This study tested the association between school-wide measures of an authoritative school climate and high school dropout rates in a statewide sample of 315 high schools. Regression models at the school level of analysis used teacher and student measures of disciplinary structure, student support, and academic expectations to predict overall high…

  3. New Approach to reduce High School Dropout Rates

    Directory of Open Access Journals (Sweden)

    Mauricio Cristhian Portillo-Torres

    2015-05-01

    Full Text Available From 2006 to 2014, the Ministry of Public Education of Costa Rica implemented four strategic actions to reduce high school dropout rates. The main purpose of these actions was to promote student participation and student identification with their school. Studies prepared by the Ministry of Education and the Comptroller of the Republic were revised to assess the impact of these actions. The result of these actions does not show an actual decrease in the number of students who leave high school. Therefore, a more holistic view is necessary to ensure the students’ stay. This review suggests using use the concept of student engagement and applying a three tier system-wide dropout preventive actions: universal, targeted and intensive.

  4. Dropout Prevention: A Study of Prevention Programs Used by High Schools to Increase Graduation Rate

    Science.gov (United States)

    Simmons, Christopher L.

    2013-01-01

    This mixed methods study focused on the relationship between dropout prevention programs and graduation rates in one school district in Florida during the 2010-2011 school year. The dropout prevention program data analyzed included high school principals' perceptions in regard to perceived effectiveness, fidelity of implementation, cost efficacy,…

  5. Factors influencing high dropout rates of girl child from education: A ...

    African Journals Online (AJOL)

    Progress in education of the girl child in sub-Saharan Africa in general and South Africa in particular has been impeded by the high rates of school dropout, which occurrence has implications for the attainment of the MDGs, particularly eradication of extreme poverty and hunger, improving the health of children and mothers, ...

  6. Trends in High School Dropout and Completion Rates in the United States: 2014. NCES 2018-117

    Science.gov (United States)

    McFarland, Joel; Cui, Jiashan; Stark, Patrick

    2018-01-01

    This report draws on an array of nationally representative surveys and administrative datasets to present statistics on high school dropout and completion rates. The report includes estimates of the percentage of students who drop out in a given 12-month period (event dropout rates), the percentage of young people in a specified age range who are…

  7. High School Dropout and Teen Childbearing

    Science.gov (United States)

    Marcotte, Dave E.

    2013-01-01

    Understanding the relationship between high school dropout and teen childbearing is complicated because both are affected by a variety of difficult to control factors. In this paper, I use panel data on aggregate dropout and fertility rates by age for all fifty states to develop insight by instrumenting for dropout using information on state…

  8. Trends in High School Dropout and Completion Rates in the United States: 1972-2012. Compendium Report. NCES 2015-015

    Science.gov (United States)

    Stark, Patrick; Noel, Amber M.

    2015-01-01

    This report builds upon a series of National Center for Education Statistics (NCES) reports on high school dropout and completion rates that began in 1988. It presents estimates of rates in 2012, provides data about trends in dropout and completion rates over the last four decades (1972-2012), and examines the characteristics of high school…

  9. When and Why Dropouts Leave High School

    Science.gov (United States)

    Stearns, Elizabeth; Glennie, Elizabeth J.

    2006-01-01

    Teens may leave school because of academic failure, disciplinary problems, or employment opportunities. In this article, the authors test whether the reasons dropouts leave school differ by grade level and age. We compare dropout rates and reasons across grade levels and ages for all high school students, ethnic groups, and gender groups. Across…

  10. An Empirical Assessment of Dropout Rate of Learners at Selected High Schools in King William’s Town, South Africa

    Directory of Open Access Journals (Sweden)

    Wendy Manona

    2015-12-01

    Full Text Available This study investigated and analysed factors responsible for high dropout rate of learners at selected high schools in King William’s Town District, Province of the Eastern Cape. The aim of the study is provide an understanding into inherent problems of early exit of learners in the education sector, which impede the long-term production of professionals with bright future. The main findings of this study revealed that multiple motives, associated with individual characteristics of dropouts and social problems emanating from their family background and influence of the community, prompted learners to dropout. Moreover, learner dropout is inter alia caused by social factors such as lack of resources, the effect of poverty, orphans at school, the distance between the school and the community, drug abuse, pregnancy and HIV and AIDS prevalence in schools, gangsterism and learning barriers. The results of this research suggest that the government should make resources available with regard to scholar transport, school nurses to provide education awareness programmes in relation to early pregnancies, HIV and AIDS infection to improve attendance rate. The Department of Social Development should provide information with regard to benefits available to orphaned learners. The government should ensure sustainable provision of the school nutrition programme to alleviate hunger and poverty. School management should effectively regulate the behaviour of learners to promote discipline in schools so that substance abuse is eliminated.

  11. Tenth Grade Dropout Rates by Native Language, Race/Ethnicity, and Socioeconomic Status

    OpenAIRE

    Rumberger, Russell W.

    2006-01-01

    One of the most important indicators of educational performance is the high school dropout rate. Reducing dropout rates and improving high school graduation rates are important goals for both educators and policymakers. Yet there is a great deal of controversy about how best to measure dropout and graduation rates. This issue of EL Facts provides estimates of dropout rates for language minority students, racial and ethnic groups, and socioeconomic groups.

  12. An Analysis of the Relationship between Implementation of School-Wide Positive Behavior Interventions and Supports and High School Dropout Rates

    Science.gov (United States)

    Freeman, Jennifer; Simonsen, Brandi; McCoach, D. Betsy; Sugai, George; Lombardi, Allison; Horner, Rob

    2015-01-01

    The purpose of this study was to explore the direct and indirect effects of SWPBIS on high school dropout rates. We used structural equation modeling methods to analyze the web of relationships among important high school level outcomes and SWPBIS in a large sample of high schools from 37 states. Results suggest that SWPBIS has statistically…

  13. San Diego's High School Dropout Crisis

    Science.gov (United States)

    Wilson, James C.

    2012-01-01

    This article highlights San Diego's dropout problem and how much it's costing the city and the state. Most San Diegans do not realize the enormous impact high school dropouts on their city. The California Dropout Research Project, located at the University of California at Santa Barbara, has estimated the lifetime cost of one class or cohort of…

  14. Patterns and Factors of High School Dropout Risks of Racial and Linguistic Groups

    Science.gov (United States)

    Kim, Sunha; Chang, Mido; Singh, Kusum; Allen, Katherine R.

    2015-01-01

    This study examined the dropout trajectories of racial and linguistic minority students and explored the effects of students' contextual factors on their high school dropout risks. Our motivation was to identify the dropout patterns of Black, Hispanic, and Hispanic English language learner (ELL) students, who have comparatively high dropout rates,…

  15. The Impact of the State-Wide and District Dropout Prevention Plans on the Dropout Rates, Graduation Rates, GED Completions, and Truancy Rates of High School Teens in Mississippi

    Science.gov (United States)

    Spencer, Amanda Jean Martin

    2011-01-01

    In 2006, as part of the compliance with the No Child Left Behind Act of 2001, Mississippi implemented a state-wide dropout prevention plan. The Mississippi Department of Education through the Office of Dropout Prevention supplied a skeletal format to serve as a guideline for all 152 individual school districts within the state. The school…

  16. Emotional Competence and Drop-Out Rates in Higher Education

    Science.gov (United States)

    Kingston, Emma

    2008-01-01

    Purpose: The purpose of this paper is to compare the emotional competence of first year undergraduates enrolled on a high or low drop-out rate (HDR and LDR, respectively) course, at a newly established university within the UK. Design/methodology/approach: A mixed methods approach using both quantitative and qualitative data collection methods was…

  17. An Examination of Dropout Rates for Hispanic or Latino Students Enrolled in Online K-12 Schools

    Science.gov (United States)

    Corry, Michael; Dardick, William; Stella, Julie

    2017-01-01

    As the number of online K-12 educational offerings continues to grow it is important to better understand key indicators of success for students enrolled in these classes. One of those indicators is student dropout rates. This is particularly important for Hispanic or Latino students who traditionally have high dropout rates. The purpose of this…

  18. Comparison of Urban and Rural Dropout Rates of Distance Students

    Science.gov (United States)

    de Hart, K. L.; Venter J. M. P.

    2013-01-01

    South Africa has one of the highest university dropout rates in the world. As a country, it also has a history of forced location and the withholding of resources, including quality education, from certain rural areas. This study investigates, the effect of urbanization (of the area in which a student resides) on the dropout rate of distance…

  19. A Comparative Study of Dropout Rates and Causes for Two Different Distance Education Courses

    Directory of Open Access Journals (Sweden)

    Christos Pierrakeas

    2004-08-01

    Full Text Available This paper reports the results of a survey conducted to examine the root causes leading to student dropout at a Greek distance education university. Data was gathered from two different courses – an undergraduate course leading to a Bachelors degree in Informatics (characterized by high dropout rates, and a postgraduate course leading to a Masters degree in education (characterized by low dropout rates. A comparative analysis of these two different courses revealed important similarities in dropout percentages and the reasons cited by students for dropping out. Our analysis also revealed important differences as well. This paper presents the results of a survey designed to investigate the relationship between dropout with intrinsic (student-related factors such as sickness, work/ school conflict etc., and extrinsic (institutional-related factors such as study methods and materials, educational approach, and tutor influence.

  20. Immunization Dropout Rates in Ihe, Awgu Local Government Area ...

    African Journals Online (AJOL)

    vaccine. Subjects and Methods: This is a cross sectional study where immunization dropout rate of ... especially with the addition of other vaccines such as yellow fever in endemic areas and tetanus toxoid (injections for the pregnant women.

  1. Addition by Subtraction: The Relation Between Dropout Rates and School-Level Academic Achievement.

    Science.gov (United States)

    Glennie, Elizabeth; Bonneau, Kara; Vandellen, Michelle; Dodge, Kenneth A

    2012-01-01

    Efforts to improve student achievement should increase graduation rates. However, work investigating the effects of student-level accountability has consistently demonstrated that increases in the standards for high school graduation are correlated with increases in dropout rates. The most favored explanation for this finding is that high-stakes testing policies that mandate grade repetition and high school exit exams may be the tipping point for students who are already struggling academically. These extra demands may, in fact, push students out of school. This article examines two hypotheses regarding the relation between school-level accountability and dropout rates. The first posits that improvements in school performance lead to improved success for everyone. If school-level accountability systems improve a school for all students, then the proportion of students performing at grade level increases, and the dropout rate decreases. The second hypothesis posits that schools facing pressure to improve their overall accountability score may pursue this increase at the cost of other student outcomes, including dropout rate. Our approach focuses on the dynamic relation between school-level academic achievement and dropout rates over time-that is, between one year's achievement and the subsequent year's dropout rate, and vice versa. This article employs longitudinal data of records on all students in North Carolina public schools over an 8-year period. Analyses employ fixed-effects models clustering schools and districts within years and controls each year for school size, percentage of students who were free/reduced-price lunch eligible, percentage of students who are ethnic minorities, and locale. This study finds partial evidence that improvements in school-level academic performance will lead to improvements (i.e., decreases) in school-level dropout rates. Schools with improved performance saw decreased dropout rates following these successes. However, we find

  2. Addition by Subtraction: The Relation Between Dropout Rates and School-Level Academic Achievement

    Science.gov (United States)

    GLENNIE, ELIZABETH; BONNEAU, KARA; VANDELLEN, MICHELLE; DODGE, KENNETH A.

    2013-01-01

    Background/Context Efforts to improve student achievement should increase graduation rates. However, work investigating the effects of student-level accountability has consistently demonstrated that increases in the standards for high school graduation are correlated with increases in dropout rates. The most favored explanation for this finding is that high-stakes testing policies that mandate grade repetition and high school exit exams may be the tipping point for students who are already struggling academically. These extra demands may, in fact, push students out of school. Purpose/Objective/Focus This article examines two hypotheses regarding the relation between school-level accountability and dropout rates. The first posits that improvements in school performance lead to improved success for everyone. If school-level accountability systems improve a school for all students, then the proportion of students performing at grade level increases, and the dropout rate decreases. The second hypothesis posits that schools facing pressure to improve their overall accountability score may pursue this increase at the cost of other student outcomes, including dropout rate. Research Design Our approach focuses on the dynamic relation between school-level academic achievement and dropout rates over time—that is, between one year’s achievement and the subsequent year’s dropout rate, and vice versa. This article employs longitudinal data of records on all students in North Carolina public schools over an 8-year period. Analyses employ fixed-effects models clustering schools and districts within years and controls each year for school size, percentage of students who were free/reduced-price lunch eligible, percentage of students who are ethnic minorities, and locale. Findings/Results This study finds partial evidence that improvements in school-level academic performance will lead to improvements (i.e., decreases) in school-level dropout rates. Schools with improved

  3. Predictors of dropout in concurrent treatment of posttraumatic stress disorder and alcohol dependence: Rate of improvement matters

    Science.gov (United States)

    Zandberg, Laurie J.; Rosenfield, David; Alpert, Elizabeth; McLean, Carmen P.; Foa, Edna B.

    2016-01-01

    Objective The present study examined predictors and moderators of dropout among 165 adults meeting DSM-IV criteria for posttraumatic stress disorder (PTSD) and alcohol dependence (AD). Participants were randomized to 24 weeks of naltrexone (NAL), NAL and prolonged exposure (PE), pill placebo, or pill placebo and PE. All participants received supportive AD counseling (the BRENDA manualized model). Method Logistic regression using the Fournier approach was conducted to investigate baseline predictors of dropout across the entire study sample. Rates of PTSD and AD symptom improvement were included to evaluate the impact of symptom change on dropout. Results Trauma type and rates of PTSD and AD improvement significantly predicted dropout, accounting for 76% of the variance in dropout. Accidents and “other” trauma were associated with the highest dropout, and physical assault was associated with the lowest dropout. For participants with low baseline PTSD severity, faster PTSD improvement predicted higher dropout. For those with high baseline severity, both very fast and very slow rates of PTSD improvement were associated with higher dropout. Faster rates of drinking improvement predicted higher dropout among participants who received PE. Conclusions The current study highlights the influence of symptom trajectory on dropout risk. Clinicians may improve retention in PTSD-AD treatments by monitoring symptom change at regular intervals, and eliciting patient feedback on these changes. PMID:26972745

  4. Predictors of dropout in concurrent treatment of posttraumatic stress disorder and alcohol dependence: Rate of improvement matters.

    Science.gov (United States)

    Zandberg, Laurie J; Rosenfield, David; Alpert, Elizabeth; McLean, Carmen P; Foa, Edna B

    2016-05-01

    The present study examined predictors and moderators of dropout among 165 adults meeting DSM-IV criteria for posttraumatic stress disorder (PTSD) and alcohol dependence (AD). Participants were randomized to 24 weeks of naltrexone (NAL), NAL and prolonged exposure (PE), pill placebo, or pill placebo and PE. All participants received supportive AD counseling (the BRENDA manualized model). Logistic regression using the Fournier approach was conducted to investigate baseline predictors of dropout across the entire study sample. Rates of PTSD and AD symptom improvement were included to evaluate the impact of symptom change on dropout. Trauma type and rates of PTSD and AD improvement significantly predicted dropout, accounting for 76% of the variance in dropout. Accidents and "other" trauma were associated with the highest dropout, and physical assault was associated with the lowest dropout. For participants with low baseline PTSD severity, faster PTSD improvement predicted higher dropout. For those with high baseline severity, both very fast and very slow rates of PTSD improvement were associated with higher dropout. Faster rates of drinking improvement predicted higher dropout among participants who received PE. The current study highlights the influence of symptom trajectory on dropout risk. Clinicians may improve retention in PTSD-AD treatments by monitoring symptom change at regular intervals, and eliciting patient feedback on these changes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Family Influences on Dropout Behavior in One California High School.

    Science.gov (United States)

    Rumberger, Russell W.; And Others

    1990-01-01

    Investigated how family processes influence high school student dropout behavior. Used a sample of 114 dropouts from 1 California high school, 48 of whom were matched to similarly profiled continuing students. Identified factors that explain students' dropout decisions: permissive parenting, negative parental reactions to grades, excessive…

  6. Adjustment of High School Dropouts in Closed Religious Communities

    Science.gov (United States)

    Itzhaki, Yael; Itzhaky, Haya; Yablon, Yaacov B.

    2018-01-01

    Background: While extensive research has been done on high-school dropouts' adjustment, there is little data on dropouts from closed religious communities. Objective: This study examines the contribution of personal and social resources to the adjustment of high school dropouts in Ultraorthodox Jewish communities in Israel. Method: Using a…

  7. Raising Their Voices: Engaging Students, Teachers, and Parents to Help End the High School Dropout Epidemic

    Science.gov (United States)

    Bridgeland, John M.; Balfanz, Robert; Moore, Laura A.; Friant, Rebecca S.

    2010-01-01

    High dropout rates continue to be a silent epidemic afflicting the nation's schools. Although some measurable progress is being made in some school districts and states to raise high school graduation rates, and federal, state, and local policies and practices are changing to meet the dropout challenge, the nation's progress is too slow and the…

  8. Pharmacogenetic analysis of opioid dependence treatment dose and dropout rate.

    Science.gov (United States)

    Crist, Richard C; Li, James; Doyle, Glenn A; Gilbert, Alex; Dechairo, Bryan M; Berrettini, Wade H

    2018-01-01

    Currently, no pharmacogenetic tests for selecting an opioid-dependence pharmacotherapy have been approved by the US Food and Drug Administration. Determine the effects of variants in 11 genes on dropout rate and dose in patients receiving methadone or buprenorphine/naloxone (ClinicalTrials.gov Identifier: NCT00315341). Variants in six pharmacokinetic genes (CYP1A2, CYP2B6, CYP2C19, CYP2C9, CYP2D6, CYP3A4) and five pharmacodynamic genes (HTR2A, OPRM1, ADRA2A, COMT, SLC6A4) were genotyped in samples from a 24-week, randomized, open-label trial of methadone and buprenorphine/naloxone for the treatment of opioid dependence (n = 764; 68.7% male). Genotypes were then used to determine the metabolism phenotype for each pharmacokinetic gene. Phenotypes or genotypes for each gene were analyzed for association with dropout rate and mean dose. Genotype for 5-HTTLPR in the SLC6A4 gene was nominally associated with dropout rate when the methadone and buprenorphine/naloxone groups were combined. When the most significant variants associated with dropout rate were analyzed using pairwise analyses, SLC6A4 (5-HTTLPR) and COMT (Val158Met; rs4860) had nominally significant associations with dropout rate in methadone patients. None of the genes analyzed in the study was associated with mean dose of methadone or buprenorphine/naloxone. This study suggests that functional polymorphisms related to synaptic dopamine or serotonin levels may predict dropout rates during methadone treatment. Patients with the S/S genotype at 5-HTTLPR in SLC6A4 or the Val/Val genotype at Val158Met in COMT may require additional treatment to improve their chances of completing addiction treatment. Replication in other methadone patient populations will be necessary to ensure the validity of these findings.

  9. Reducing School Factors That Lead to Student Dropout at Sussex Central High School

    Science.gov (United States)

    Jerns, Pamela Renee

    2012-01-01

    The focus of this Executive Position Paper (EPP) is to address the dropout rate at Sussex Central High School (SCHS) in the Indian River School District (IRSD). Studies conducted for this EPP align with current research--student dropout is a result of culminating school-based factors that include poor attendance and lack of exposure to rigorous…

  10. Trends in High School Dropout and Completion Rates in the United States: 2013. Compendium Report. NCES 2016-117

    Science.gov (United States)

    McFarland, Joel; Stark, Patrick; Cui, Jiashan

    2016-01-01

    Dropping out of high school is related to a number of negative outcomes. For example, the median income of persons ages 18 through 67 who had not completed high school was roughly $26,000 in 2013. By comparison, the median income of persons ages 18 through 67 who completed their education with at least a high school credential (i.e., a regular…

  11. Immunization Dropout Rates in Ihe, Awgu Local Government Area ...

    African Journals Online (AJOL)

    Background: Immunization against childhood diseases is one of the most important ways of preventing childhood morbidity and mortality. Aims: The objective of this study is to review the dropout rates of immunization of children in a health center using a single dose of diphtheria‑pertussis‑tetanus (DPT1) and three doses of ...

  12. Factors influencing dropout rate of intermittent preventive treatment of malaria during pregnancy.

    Science.gov (United States)

    Doku, David Teye; Zankawah, Mumuni Mukaila; Adu-Gyamfi, Addae Boateng

    2016-10-10

    The burden of malaria in terms of morbidity and mortality is huge is Sub-Saharan Africa, particularly among pregnant women. Among the measures to curb down this burden include intermittent preventive treatment (IPT) and effective case management. These strategies were adopted by Ghana and implemented since 2003; however, there is still high dropout rate in IPT coverage. This study sought to investigate factors contributing to high dropout rate between IPT1 and IPT3 in the Tamale Metropolis, one of the health facilities with the highest IPT dropout rates in Ghana. Survey, in-depth interviews and short ethnographic techniques were conducted among pregnant women, antenatal care (ANC) health workers and heads of health facilities to investigate factors which account for dropout rate of intermittent treatment of malaria. Shortage of sulphadoxine pyrimethamine (SP), inadequate supply of portable water for administration of SP, unavailability of IPT during outreach services, lack of knowledge by ANC staff about the dropout rate in their area of jurisdiction and poor attitude of some health workers were identified as barriers to achieving high IPT3 coverage. Late ANC visit, provider and logistical barriers account for the women's missed opportunities to prevent malaria in pregnancy through IPT. Addressing the above barriers will contribute to saving lives and ensuring progress towards the goal of combating malaria as well as reducing maternal, neonatal and child mortalities.

  13. Public High School Four-Year On-Time Graduation Rates and Event Dropout Rates: School Years 2010-11 and 2011-12. First Look. NCES 2014-391

    Science.gov (United States)

    Stetser, Marie C.; Stillwell, Robert

    2014-01-01

    This National Center for Education Statistics (NCES) First Look report introduces new data for two separate measures of 4-year on-time graduation rates as well as event dropout rates for school year (SY) 2010-11 and SY 2011-12. Specifically this report provides the following: (1) Four-year adjusted cohort graduation rate (ACGR) data reported by…

  14. Aggressive Students and High School Dropout: An Event History Analysis

    Science.gov (United States)

    Orozco, Steven R.

    2016-01-01

    Aggressive students often struggle in multiple domains of their school functioning and are at increased risk for high school dropout. Research has identified a variety of warning flags which are strong predictors of high school dropout. While it is known that aggressive students exhibit many of these warning flags, there is little research which…

  15. Teacher professionalisation and dropout rates in adult education

    DEFF Research Database (Denmark)

    Wahlgren, Bjarne; Mariager-Anderson, Kristina

    2015-01-01

    in by the teachers, interviews with the teachers, and by the teachers’ written logbooks. The preliminary conclusion is that it is the general attitude in the teacher groups towards the importance of improving retention that is of significance for the documented effects on the drop-out rates.......This article reports findings from a research project titled New roles for the teacher - Increased completion through social responsibility. This research, designed as an intervention project, has an overall aim of reducing absence and drop-out rates in the Danish vocational and general adult...... educational system by developing and improving the teachers’ competences. This has been pursued in the research project through engaging teachers in training aimed at improving their socio-pedagogical competences. The effect of this training has been measured by electronic questionnaires filled...

  16. Does the Economic Crisis Have an Influence on the Higher Education Dropout Rate?

    Science.gov (United States)

    Leão Fernandes, Graça; Chagas Lopes, Margarida

    2016-01-01

    This research aims to identify the effects of the economic crisis on higher education (HE) dropout rates at Lisbon School of Economics and Management (ISEG)--Universidade de Lisboa, after having controlled for individual characteristics, family background, High School and HE trajectories. Our main hypothesis is that the economic crisis induces…

  17. Dropout and Federal Graduation Rates 2013-2014. Research Brief. Volume 1407

    Science.gov (United States)

    Froman, Terry

    2015-01-01

    The District conducts two kinds of dropout analyses every year in Miami-Dade County Public Schools. The "cross-sectional" analysis of student dropouts examines dropout rates among students enrolled in various grades at one point in time. A "longitudinal" analysis, also conducted annually, tracks a group of students in the same…

  18. Finishing high school: alternative pathways and dropout recovery.

    Science.gov (United States)

    Tyler, John H; Lofstrom, Magnus

    2009-01-01

    John Tyler and Magnus Lofstrom take a close look at the problems posed when students do not complete high school. The authors begin by discussing the ongoing, sometimes heated, debate over how prevalent the dropout problem is. They note that one important reason for discrepancies in reported dropout rates is whether holders of the General Educational Development (GED) credential are counted as high school graduates. The authors also consider the availability of appropriate student data. The overall national dropout rate appears to be between 22 and 25 percent, but the rate is higher among black and Hispanic students, and it has not changed much in recent decades. Tyler and Lofstrom conclude that schools are apparently doing about as well now as they were forty years ago in terms of graduating students. But the increasingly competitive pressures associated with a global economy make education ever more important in determining personal and national well-being. A student's decision to drop out of school, say the authors, is affected by a number of complex factors and is often the culmination of a long process of disengagement from school. That decision, not surprisingly, carries great cost to both the student and society. Individual costs include lower earnings, higher likelihood of unemployment, and greater likelihood of health problems. Because minority and low-income students are significantly more likely than well-to-do white students to drop out of school, the individual costs fall unevenly across groups. Societal costs include loss of tax revenue, higher spending on public assistance, and higher crime rates. Tyler and Lofstrom go on to survey research on programs designed to reduce the chances of students' dropping out. Although the research base on this question is not strong, they say, close mentoring and monitoring of students appear to be critical components of successful programs. Other dropout-prevention approaches associated with success are family

  19. High School Dropouts: Interactions between Social Context, Self-Perceptions, School Engagement, and Student Dropout

    Science.gov (United States)

    Fall, Anna-Maria; Roberts, Greg

    2012-01-01

    Research suggests that contextual, self-system, and school engagement variables influence dropping out from school. However, it is not clear how different types of contextual and self-system variables interact to affect students' engagement or contribute to decisions to dropout from high school. The self-system model of motivational development…

  20. On the Front Lines of Schools: Perspectives of Teachers and Principals on the High School Dropout Problem

    Science.gov (United States)

    Bridgeland, John M.; Dilulio, John J., Jr.; Balfanz, Robert

    2009-01-01

    Teachers and administrators in public high schools recognize there is a dropout problem, know they are confronted with daunting challenges in classrooms and in schools, and express strong support for reforms to address high dropout rates. Yet, less than one-third of teachers believe that schools should expect all students to meet high academic…

  1. Adolescent use of school-based health centers and high school dropout.

    Science.gov (United States)

    Kerns, Suzanne E U; Pullmann, Michael D; Walker, Sarah Cusworth; Lyon, Aaron R; Cosgrove, T J; Bruns, Eric J

    2011-07-01

    To determine the association between use of school-based health centers (SBHCs) and school dropout. Quasi-experimental longitudinal analysis of a retrospective student cohort, with SBHC use as the independent variable. We statistically controlled for dropout risk and used propensity score regression adjustment to control for several factors associated with SBHC use. Integrated database from an urban public school district (academic outcomes) and department of public health (SBHC use). District-enrolled students in their first semester of ninth grade in 2005 (N = 3334), followed up through their anticipated on-time graduation semester of 12th grade in 2009. Students were divided into 4 groups: never used (47%); low use (23%); moderate use (20%); and high users (10%). Time to nongraduation (described as dropout). Low to moderate SBHC use (0.125-2.5 visits per semester) was associated with a 33% reduction in dropout compared with non-SBHC users. The high-use group (>2.5 visits per semester) did not have dropout rates that differed from nonusers. For SBHC users who did drop out, dropout occurred approximately 1 semester later than nonusers. Exploratory analyses revealed that the association between SBHC use and prevention of dropout was greatest for higher-risk students. This study found an association between low to moderate SBHC use and reductions in dropout for high school students in an urban school district, especially for students at higher risk for dropout. This study supports the theory that benefits of SBHCs extend beyond managing physical and mental health needs to include academic outcomes.

  2. DECREASING SCHOOL DROPOUT RATE AS A FACTOR OF ECONOMIC GROWTH AND SOCIAL EMPOWERMENT. THEORETICAL INSIGHTS

    Directory of Open Access Journals (Sweden)

    Alina Badulescu

    2016-07-01

    Full Text Available Economic development and social empowerment in Romania are unconcievable in the absence of a modern education system, which needs both economic and financial investments and social, political, cultural measures to increase the inclusion of young people in school system. In this particular context, given that Romania faces a high degree rate of school dropout, and moreover there are few chances that Romania reach its goals, we try in this paper to look inside the real situation. Indeed, school dropout present serious negative consequences both on individual level and for the whole society. Recognising this fact, next step is to investigate and reveal the determining factors for this situation, and we are particularly interested in the economic and systemic factors. Consequently, we present in this paper first a brief literature review on the fenomenon of school dropping out, including reviewing main studies related to factors, effects, causes etc. In the second part, starting from several statistical data provided by INS, EUROSTAT and UNICEF studies, we propose some theoretical models and policy reccomendations in order to decrease the school dropout rate and especially the early school dropout rate.

  3. Student engagement and its relationship with early high school dropout.

    Science.gov (United States)

    Archambault, Isabelle; Janosz, Michel; Fallu, Jean-Sébastien; Pagani, Linda S

    2009-06-01

    Although the concept of school engagement figures prominently in most school dropout theories, there has been little empirical research conducted on its nature and course and, more importantly, the association with dropout. Information on the natural development of school engagement would greatly benefit those interested in preventing student alienation during adolescence. Using a longitudinal sample of 11,827 French-Canadian high school students, we tested behavioral, affective, cognitive indices of engagement both separately and as a global construct. We then assessed their contribution as prospective predictors of school dropout using factor analysis and structural equation modeling. Global engagement reliably predicted school dropout. Among its three specific dimensions, only behavioral engagement made a significant contribution in the prediction equation. Our findings confirm the robustness of the overall multidimensional construct of school engagement, which reflects both cognitive and psychosocial characteristics, and underscore the importance attributed to basic participation and compliance issues in reliably estimating risk of not completing basic schooling during adolescence.

  4. A meta-analysis of dropout rates in acceptance and commitment therapy.

    Science.gov (United States)

    Ong, Clarissa W; Lee, Eric B; Twohig, Michael P

    2018-05-01

    Many psychotherapies, including cognitive behavioral therapy and acceptance and commitment therapy (ACT), have been found to be effective interventions for a range of psychological and behavioral health concerns. Another aspect of treatment utility to consider is dropout, as interventions only work if clients are engaged in them. To date, no research has used meta-analytic methods to examine dropout in ACT. Thus, the objectives of the present meta-analysis were to (1) determine the aggregate dropout rate for ACT in randomized controlled trials, (2) compare dropout rates in ACT to those in other psychotherapies, and (3) identify potential moderators of dropout in ACT. Our literature search yielded 68 studies, representing 4,729 participants. The weighted mean dropout rates in ACT exclusive conditions and ACT inclusive conditions (i.e., those that included an ACT intervention) were 15.8% (95% CI: 11.9%, 20.1%) and 16.0% (95% CI: 12.5%, 19.8%), respectively. ACT dropout rates were not significantly different from those of established psychological treatments. In addition, dropout rates did not vary by client characteristics or study methodological quality. However, master's-level clinicians/therapists (weighted mean = 29.9%, CI: 17.6%, 43.8%) were associated with higher dropout than psychologists (weighted mean = 12.4%, 95% CI: 6.7%, 19.4%). More research on manipulable, process variables that influence dropout is needed. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. Locating the Dropout Crisis. Which High Schools Produce the Nation's Dropouts? Where Are They Located? Who Attends Them? Report 70

    Science.gov (United States)

    Balfanz, Robert; Legters, Nettie

    2004-01-01

    The purpose of this report was to locate the dropout crisis- to determine its scale and scope by identifying the number of high schools with severe dropout problems, detailing the states, cities, and locales where they are concentrated, and establishing who attends them. For this analysis of high schools across the country, two cut-points were…

  6. Drop-out rate and drop-out reasons among promising Norwegian track and field athletes: a 25 year study

    OpenAIRE

    Enoksen, Eystein

    2011-01-01

    © Eystein Enoksen, 2011 The aim of the present study was to identify the total drop-out rate and drop-out reasons for a group of promising track and field athletes. 202 males and 98 females, aged 16 ±2 years, took part in this study. Questionnaires were administrated in 1975, 1983, and 1989. In-depth interviews were conducted in 1989 and in 2000. A chi-square test was administrated to test the difference between males and females dropping out and to test the most significant reasons influe...

  7. Immunization dropout rate and data quality among children 12-23 months of age in Ghana.

    Science.gov (United States)

    Baguune, Benjamin; Ndago, Joyce Aputere; Adokiya, Martin Nyaaba

    2017-01-01

    Immunization against diseases is one of the most important public health interventions with cost effective means to preventing childhood morbidity, mortality and disability. However, a proportion of children particularly in Africa are not fully immunized with the recommended vaccines. Thus, many children are still susceptible to the Expanded Program on Immunization (EPI) targeted diseases. The objective of this study was to determine the immunization dropout rate and data quality among children aged 12-23 months in Techiman Municipality, Ghana. A cross-sectional cluster survey was conducted among 600 children. Data was collected using semi-structured questionnaire through face-to-face interviews. Before the main data collection, the tools were pre-tested in three different communities in the Municipality. The mothers/caregivers were interviewed, extracted information from the child immunization cards and observation employed to confirm the presence of Bacillus Calmette-Guerin (BCG) scar on each child. Routine immunization data was also extracted from immunization registers and annual reports in the Municipality. I mmunization coverage for each of the fifteen vaccines doses is above 90.0% while full childhood immunized status is 89.5%. Immunization dropout rate was 5.6% (using BCG and Measles as proxy vaccines). This is lower than the 10.0% cutoff point by World Health Organization. However, routine administrative data was characterized by some discrepancies (e.g. > 100.0% immunization coverage for each of the vaccines) and high dropout rate (BCG - Measles = 31.5%). Binary regression was performed to determine predictors of dropout rate. The following were statistically significant: married (OR = 0.31; 95% = CI 0.15-0.62; and p  = 0.001), Christianity (OR = 0.27; 95% CI = 0.13-0.91; and p  dropout. Childhood full immunized status (89.5%) and immunization coverages (>90%) are high while dropout rate is lower than the recommended cutoff point by WHO

  8. Working While Studying: The Impact of Term-Time Employment on Dropout Rates

    Science.gov (United States)

    Hovdhaugen, Elisabeth

    2015-01-01

    There are many possible reasons why students leave university prior to degree completion, and one of the more commonly cited is being employed while studying. This paper analyses the impact of employment status on dropout rates using survival analysis. It finds that employment status does have an impact on dropout rates; students who work full…

  9. Longitudinal Examination of Aggression and Study Skills from Middle to High School: Implications for Dropout Prevention

    Science.gov (United States)

    Orpinas, Pamela; Raczynski, Katherine; Hsieh, Hsien-Lin; Nahapetyan, Lusine; Horne, Arthur M.

    2018-01-01

    Background: High school completion provides health and economic benefits. The purpose of this study is to describe dropout rates based on longitudinal trajectories of aggression and study skills using teacher ratings. Methods: The sample consisted of 620 randomly selected sixth graders. Every year from Grade 6 to 12, a teacher completed a…

  10. High School Dropouts: Implications in the Economic Development of West Virginia. Research Paper 9909.

    Science.gov (United States)

    De Sousa, Semoa C. B.; Gebremedhin, Tesfa

    Despite increased government investments in education, West Virginia continues to have one of the nation's highest high school dropout rates and is among the states with the highest unemployment rates. Human capital theory provides the conceptual basis for evaluating the relationship between investment in education and economic development. An…

  11. The High School Dropout Problem: Perspectives of Teachers and Principals

    Science.gov (United States)

    Bridgeland, John M.; Dilulio, John J., Jr.; Balfanz, Robert

    2009-01-01

    To better understand the views of teachers and administrators on the high school dropout problem, focus groups and nationally representative surveys were conducted of high school teachers and principals. A focus group of superintendents and school board members was also included. To help interpret the results, the authors convened a colloquium…

  12. Building a Grad Nation: Progress and Challenge in Ending the High School Dropout Epidemic

    Science.gov (United States)

    Balfanz, Robert; Bridgeland, John M.; Moore, Laura A.; Fox, Joanna Hornig

    2010-01-01

    The central message of this report is that some states and school districts are raising their high school graduation rates with scalable solutions in the public schools, showing the nation they can end the high school dropout crisis. America made progress not only in suburbs and towns, but also in urban districts and in states across the South.…

  13. Dropout and Graduation Rates 2007-2008. Research Brief. Volume 0804

    Science.gov (United States)

    Research Services, Miami-Dade County Public Schools, 2009

    2009-01-01

    The District conducts a "cross-sectional" analysis of student dropouts annually; it examines dropout rates among students enrolled in various grades at one point in time. A "longitudinal" analysis, also conducted annually, tracks a group of students in the same grade or cohort over a period of several years. Each method…

  14. Dropout and Graduation Rates 2008-2009. Research Brief. Volume 0902

    Science.gov (United States)

    Research Services, Miami-Dade County Public Schools, 2010

    2010-01-01

    The District conducts a "cross-sectional" analysis of student dropouts annually; it examines dropout rates among students enrolled in various grades at one point in time. A "longitudinal" analysis, also conducted annually, tracks a group of students in the same grade or cohort over a period of several years. Each method…

  15. Dropout and Graduation Rates 2009-2010. Research Brief. Volume 1101

    Science.gov (United States)

    Research Services, Miami-Dade County Public Schools, 2011

    2011-01-01

    The District conducts a "cross-sectional" analysis of student dropouts annually; it examines dropout rates among students enrolled in various grades at one point in time. A "longitudinal" analysis, also conducted annually, tracks a group of students in the same grade or cohort over a period of several years. Each method…

  16. Dropout and Graduation Rates 2010-2011. Research Brief. Volume 1107

    Science.gov (United States)

    Research Services, Miami-Dade County Public Schools, 2012

    2012-01-01

    The District conducts a "cross-sectional" analysis of student dropouts annually; it examines dropout rates among students enrolled in various grades at one point in time. A "longitudinal" analysis, also conducted annually, tracks a group of students in the same grade or cohort over a period of several years. Each method…

  17. Determinants of High-School Dropout: A Longitudinal Study in a Deprived Area of Japan.

    Science.gov (United States)

    Tabuchi, Takahiro; Fujihara, Sho; Shinozaki, Tomohiro; Fukuhara, Hiroyuki

    2018-05-19

    Our objective in this study was to find determinants of high-school dropout in a deprived area of Japan using longitudinal data, including socio-demographic and junior high school-period information. We followed 695 students who graduated the junior high school located in a deprived area of Japan between 2002 and 2010 for 3 years after graduation (614 students: follow-up rate, 88.3%). Multivariable log-binomial regression models were used to calculate the prevalence ratios (PRs) for high-school dropout, using multiple imputation (MI) to account for non-response at follow-up. The MI model estimated that 18.7% of students dropped out of high school in approximately 3 years. In the covariates-adjusted model, three factors were significantly associated with high-school dropout: ≥10 days of tardy arrival in junior high school (PR 6.44; 95% confidence interval [CI], 1.69-24.6 for "10-29 days of tardy arrival" and PR 8.01; 95% CI, 2.05-31.3 for "≥30 days of tardy arrival" compared with "0 day of tardy arrival"), daily smoking (PR 2.01; 95% CI, 1.41-2.86) and severe problems, such as abuse and neglect (PR 1.66; 95% CI, 1.16-2.39). Among students with ≥30 days of tardy arrival in addition to daily smoking or experience of severe problems, ≥50% high-school dropout rates were observed. Three determinants of high-school dropout were found: smoking, tardy arrival, and experience of severe problems. These factors were correlated and should be treated as warning signs of complex behavioral and academic problems. Parents, educators, and policy makers should work together to implement effective strategies to prevent school dropout.

  18. Did the 18 Drinking Age Promote High School Dropout? Implications for Current Policy.

    Science.gov (United States)

    Plunk, Andrew D; Agrawal, Arpana; Tate, William F; Cavazos-Rehg, Patricia; Bierut, Laura J; Grucza, Richard A

    2015-09-01

    Disagreement exists over whether permissive minimum legal drinking age (MLDA) laws affected underage adolescents (e.g., those age 17 years with the MLDA of 18). We used MLDA changes during the 1970s and 1980s as a natural experiment to investigate how underage exposure to permissive MLDA affected high school dropout. MLDA exposure was added to two data sets: (a) the 5% public use microdata samples of the 1990 and 2000 censuses (n = 3,671,075), and (b) a combined data set based on the 1991-1992 National Longitudinal Alcohol Epidemiological Survey (NLAES) and the 2001-2002 National Epidemiological Survey on Alcohol and Related Conditions (NESARC; n = 16,331). We used logistic regression to model different thresholds of MLDA on high school dropout. We also estimated models conditioned on demographic variables and familial risk of developing alcohol problems. Only the MLDA of 18 predicted high school dropout. Exposure was associated with 4% and 13% higher odds of high school dropout for the census and NLAES/NESARC samples, respectively. We noted greater impact on women (5%-18%), Blacks (5%-19%), and Hispanics (6%). Self-report of parental alcohol problems was associated with 40% higher odds, which equals a 4.14-point increase in dropout rate for that population. The MLDA of 18 likely had a large impact on high school dropout rates, suggesting that the presence of legal-aged peers in a high school setting increased access to alcohol for younger students. Our results also suggest that policy can promote less dangerous drinking behavior even when familial risk of alcohol use disorders is high.

  19. Effect of the Transcendental Meditation Program on Graduation, College Acceptance and Dropout Rates for Students Attending an Urban Public High School

    Science.gov (United States)

    Colbert, Robert D.

    2013-01-01

    High school graduation rates nationally have declined in recent years, despite public and private efforts. The purpose of the current study was to determine whether practice of the Quiet Time/Transcendental Meditation® program at a medium-size urban school results in higher school graduation rates compared to students who do not receive training…

  20. A District View: Dropouts and the Differentiated Diploma

    Science.gov (United States)

    Holden, E. Todd

    2012-01-01

    More students are deciding to dropout of school prior to graduation. As a result the dropout rate has become a hot topic in education across the United States. The average high school dropout salary is approximately 50% less than the salary of a high school graduate. The social factors are another reason the dropout rate needs to be a high…

  1. Higher dropout rate in non-native patients than in native patients in rehabilitation in The Netherlands

    NARCIS (Netherlands)

    Sloots, Maurits; Scheppers, Emmanuel F.; van de Weg, Frans B.; Bartels, Edien A.; Geertzen, Jan H.; Dekker, Joost; Dekker, Jaap

    Dropout from a rehabilitation programme often occurs in patients with chronic nonspecific low back pain of non-native origin. However, the exact dropout rate is not known. The objective of this study was to determine the difference in dropout rate between native and non-native patients with chronic

  2. High school dropouts: interactions between social context, self-perceptions, school engagement, and student dropout.

    Science.gov (United States)

    Fall, Anna-Mária; Roberts, Greg

    2012-08-01

    Research suggests that contextual, self-system, and school engagement variables influence dropping out from school. However, it is not clear how different types of contextual and self-system variables interact to affect students' engagement or contribute to decisions to dropout from high school. The self-system model of motivational development represents a promising theory for understanding this complex phenomenon. The self-system model acknowledges the interactive and iterative roles of social context, self-perceptions, school engagement, and academic achievement as antecedents to the decision to dropout of school. We analyzed data from the Education Longitudinal Study of 2002-2004 in the context of the self-system model, finding that perception of social context (teacher support and parent support) predicts students' self-perceptions (perception of control and identification with school), which in turn predict students' academic and behavioral engagement, and academic achievement. Further, students' academic and behavioral engagement and achievement in 10th grade were associated with decreased likelihood of dropping out of school in 12th grade. Published by Elsevier Ltd.

  3. Marijuana Use and High School Dropout: The Influence of Unobservables

    OpenAIRE

    Daniel F. McCaffrey; Rosalie Liccardo Pacula; Bing Han; Phyllis Ellickson

    2008-01-01

    In this study we reconsider the relationship between heavy and persistent marijuana use and high school dropout status using a unique prospective panel study of over 4500 7th grade students from South Dakota who are followed up through high school. Propensity score weighting is used to adjust for baseline differences that are found to exist before marijuana initiation occurs (7th grade). Weighted logistic regression incorporating these propensity score weights is then used to examine the exte...

  4. The effects of the bologna process on college enrollment and drop-out rates

    OpenAIRE

    Horstschräer, Julia; Sprietsma, Maresa

    2010-01-01

    This paper estimates the short-term effects of the introduction of the Bachelor degree in the framework of the Bologna Process on college enrollment and drop-out rates. We use variation in the timing of the Bachelor implementation at the department level to identify the effect of the reform based on longitudinal administrative student data from Germany. We find no significant effects on college enrollment or drop-out rates for most subjects.

  5. Revisiting the Link Between Depression Symptoms and High School Dropout: Timing of Exposure Matters.

    Science.gov (United States)

    Dupéré, Véronique; Dion, Eric; Nault-Brière, Frédéric; Archambault, Isabelle; Leventhal, Tama; Lesage, Alain

    2018-02-01

    Recent reviews concluded that past depression symptoms are not independently associated with high school dropout, a conclusion that could induce schools with high dropout rates and limited resources to consider depression screening, prevention, and treatment as low-priority. Even if past symptoms are not associated with dropout, however, it is possible that recent symptoms are. The goal of this study was to examine this hypothesis. In 12 disadvantaged high schools in Montreal (Canada), all students at least 14 years of age were first screened between 2012 and 2015 (N screened  = 6,773). Students who dropped out of school afterward (according to school records) were then invited for interviews about their mental health in the past year. Also interviewed were matched controls with similar risk profiles but who remained in school, along with average not at-risk schoolmates (N interviewed  = 545). Interviews were conducted by trained graduate students. Almost one dropout out of four had clinically significant depressive symptoms in the 3 months before leaving school. Adolescents with recent symptoms had an odd of dropping out more than twice as high as their peers without such symptoms (adjusted odds ratio = 2.17; 95% confidence interval = 1.14-4.12). In line with previous findings, adolescents who had recovered from earlier symptoms were not particularly at risk. These findings suggest that to improve disadvantaged youths' educational outcomes, investments in comprehensive mental health services are needed in schools struggling with high dropout rates, the very places where adolescents with unmet mental health needs tend to concentrate. Copyright © 2017 The Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  6. Continuous Dropout.

    Science.gov (United States)

    Shen, Xu; Tian, Xinmei; Liu, Tongliang; Xu, Fang; Tao, Dacheng

    2017-10-03

    Dropout has been proven to be an effective algorithm for training robust deep networks because of its ability to prevent overfitting by avoiding the co-adaptation of feature detectors. Current explanations of dropout include bagging, naive Bayes, regularization, and sex in evolution. According to the activation patterns of neurons in the human brain, when faced with different situations, the firing rates of neurons are random and continuous, not binary as current dropout does. Inspired by this phenomenon, we extend the traditional binary dropout to continuous dropout. On the one hand, continuous dropout is considerably closer to the activation characteristics of neurons in the human brain than traditional binary dropout. On the other hand, we demonstrate that continuous dropout has the property of avoiding the co-adaptation of feature detectors, which suggests that we can extract more independent feature detectors for model averaging in the test stage. We introduce the proposed continuous dropout to a feedforward neural network and comprehensively compare it with binary dropout, adaptive dropout, and DropConnect on Modified National Institute of Standards and Technology, Canadian Institute for Advanced Research-10, Street View House Numbers, NORB, and ImageNet large scale visual recognition competition-12. Thorough experiments demonstrate that our method performs better in preventing the co-adaptation of feature detectors and improves test performance.

  7. Systematic review and meta-analysis of dropout rates in individual psychotherapy for generalized anxiety disorder.

    Science.gov (United States)

    Gersh, Elon; Hallford, David J; Rice, Simon M; Kazantzis, Nikolaos; Gersh, Hannah; Gersh, Benji; McCarty, Carolyn A

    2017-12-01

    Despite being a relatively prevalent and debilitating disorder, Generalized Anxiety Disorder (GAD) is the second least studied anxiety disorder and among the most difficult to treat. Dropout from psychotherapy is concerning as it is associated with poorer outcomes, leads to service inefficiencies and can disproportionately affect disadvantaged populations. No study to date has calculated a weighted mean dropout rate for GAD and explored associated correlates. A systematic review was conducted using PsycINFO, Medline and Embase databases, identifying studies investigating individual psychotherapies for adults with GAD. Forty-five studies, involving 2224 participants, were identified for meta-analysis. The weighted mean dropout rate was 16.99% (95% confidence interval 14.42%-19.91%). The Q-statistic indicated significant heterogeneity among studies. Moderator analysis and meta-regressions indicated no statistically significant effect of client age, sex, symptom severity, comorbidity, treatment type, study type (randomized trial or not), study quality, number of sessions or therapist experience. In research investigating psychotherapy for GAD, approximately one in six clients can be expected to drop out of treatment. Dropout rate was not significantly moderated by the client, therapist or treatment variables investigated. Future research should specify the definition of dropout, reasons for dropout and associated correlates to assist the field's progression. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Dose-rate effects of low-dropout voltage regulator at various biases

    International Nuclear Information System (INIS)

    Wang Yiyuan; Zheng Yuzhan; Gao Bo; Chen Rui; Fei Wuxiong; Lu Wu; Ren Diyuan

    2010-01-01

    A low-dropout voltage regulator, LM2941, was irradiated by 60 Co γ-rays at various dose rates and biases for investigating the total dose and dose rate effects. The radiation responses show that the key electrical parameters, including its output and dropout voltage, and the maximum output current, are sensitive to total dose and dose rates, and are significantly degraded at low dose rate and zero bias. The integrated circuits damage change with the dose rates and biases, and the dose-rate effects are relative to its electric field. (authors)

  9. Longitudinal Examination of Aggression and Study Skills From Middle to High School: Implications for Dropout Prevention.

    Science.gov (United States)

    Orpinas, Pamela; Raczynski, Katherine; Hsieh, Hsien-Lin; Nahapetyan, Lusine; Horne, Arthur M

    2018-03-01

    High school completion provides health and economic benefits. The purpose of this study is to describe dropout rates based on longitudinal trajectories of aggression and study skills using teacher ratings. The sample consisted of 620 randomly selected sixth graders. Every year from Grade 6 to 12, a teacher completed a nationally normed behavioral rating scale. We used latent class mixture modeling to identify the trajectories. Participants followed 3 trajectories of aggression (Low, Medium Desisting, and High Desisting) and 5 trajectories of study skills (Low, Average-Low, Decreasing, Increasing, and High). Over three-quarters of the sample were in stable trajectories of study skills over time. Most students in the High Desisting Aggression group were in the Low Study Skills group, and all students in the High Study Skills group were in the Low Aggression group. The overall dropout rate was 17%, but varied dramatically across combined aggression and study skills groups, ranging from 2% to 50%. The results highlight the importance of early prevention that combines academic enhancement and behavioral management for reducing school dropout. © 2018, American School Health Association.

  10. Building a Grad Nation: Progress and Challenge in Ending the High School Dropout Epidemic. Annual Update 2015

    Science.gov (United States)

    DePaoli, Jennifer L.; Fox, Joanna Hornig; Ingram, Erin S.; Maushard, Mary; Bridgeland, John M.; Balfanz, Robert

    2015-01-01

    In 2013, the national high school graduation rate hit a record high of 81.4 percent, and for the third year in a row, the nation remained on pace to meet the 90 percent goal by the Class of 2020. This sixth annual update on America's high school dropout challenge shows that these gains have been made possible by raising graduation rates for…

  11. Building a Grad Nation: Progress and Challenge in Ending the High School Dropout Epidemic. Annual Update 2014

    Science.gov (United States)

    Balfanz, Robert; Bridgeland, John M.; Fox, Joanna Hornig; DePaoli, Jennifer L.; Ingram, Erin S.; Maushard, Mary

    2014-01-01

    This fifth annual update on America's high school dropout crisis shows that, for the first time in history, the nation has crossed the 80 percent high school graduation rate threshold and remains on pace, for the second year in a row, to meet the goal of a 90 percent high school graduation rate by the Class of 2020. This report highlights key…

  12. Latent profile analysis of sixth graders based on teacher ratings: Association with school dropout.

    Science.gov (United States)

    Orpinas, Pamela; Raczynski, Katherine; Peters, Jaclyn Wetherington; Colman, Laura; Bandalos, Deborah

    2015-12-01

    The goal of this study was to identify meaningful groups of sixth graders with common characteristics based on teacher ratings of assets and maladaptive behaviors, describe dropout rates for each group, and examine the validity of these groups using students' self-reports. The sample consisted of racially diverse students (n = 675) attending sixth grade in public schools in Northeast Georgia. The majority of the sample was randomly selected; a smaller group was identified by teachers as high risk for aggression. Based on teacher ratings of externalizing behaviors, internalizing problems, academic skills, leadership, and social assets, latent profile analysis yielded 7 classes that can be displayed along a continuum: Well-Adapted, Average, Average-Social Skills Deficit, Internalizing, Externalizing, Disruptive Behavior with School Problems, and Severe Problems. Dropout rate was lowest for the Well-adapted class (4%) and highest for the Severe Problems class (58%). However, students in the Average-Social Skills Deficit class did not follow the continuum, with a large proportion of students who abandoned high school (29%). The proportion of students identified by teachers as high in aggression consistently increased across the continuum from none in the Well-Adapted class to 84% in the Severe Problems class. Students' self-reports were generally consistent with the latent profile classes. Students in the Well-Adapted class reported low aggression, drug use, and delinquency, and high life satisfaction; self-reports went in the opposite direction for the Disruptive Behaviors with School Problems class. Results highlight the importance of early interventions to improve academic performance, reduce externalizing behaviors, and enhance social assets. (c) 2015 APA, all rights reserved).

  13. Dropout Rates and Response Times of an Occupation Search Tree in a Web Survey

    Directory of Open Access Journals (Sweden)

    Tijdens Kea

    2014-03-01

    Full Text Available Occupation is key in socioeconomic research. As in other survey modes, most web surveys use an open-ended question for occupation, though the absence of interviewers elicits unidentifiable or aggregated responses. Unlike other modes, web surveys can use a search tree with an occupation database. They are hardly ever used, but this may change due to technical advancements. This article evaluates a three-step search tree with 1,700 occupational titles, used in the 2010 multilingual WageIndicator web survey for UK, Belgium and Netherlands (22,990 observations. Dropout rates are high; in Step 1 due to unemployed respondents judging the question not to be adequate, and in Step 3 due to search tree item length. Median response times are substantial due to search tree item length, dropout in the next step and invalid occupations ticked. Overall the validity of the occupation data is rather good, 1.7-7.5% of the respondents completing the search tree have ticked an invalid occupation.

  14. The influence of different curriculum designs on students' dropout rate: a case study.

    Science.gov (United States)

    Vergel, John; Quintero, Gustavo A; Isaza-Restrepo, Andrés; Ortiz-Fonseca, Martha; Latorre-Santos, Catalina; Pardo-Oviedo, Juan Mauricio

    2018-12-01

    The relationship between students' withdrawal and educational variables has generated a considerable number of publications. As the explosion of information in sciences and integration theories led to creating different curriculum designs, it has been assumed that differences among designs explain academic success and, therefore, students' retention. However, little attention has been given to examine explicitly how diverse designs influence dropout rates in practice, which questions if decisions to reform curricula are sufficiently informed. This article describes our curriculum reform, which exposes our former and current curriculum designs as having had dissimilar dropout percentages. Furthermore, we aimed to explore the influence of different curriculum designs on students' dropout rates. The conclusion is that dropout variations may be explained not only because of the curriculum design itself, but also because of the power relationship changes between teachers and students that brought out the design change. Consequently, more research is needed to fully understand the political implications of different curriculum designs and their influence on dropout rates.

  15. The influence of different curriculum designs on students’ dropout rate: a case study

    Science.gov (United States)

    Vergel, John; Quintero, Gustavo A.; Isaza-Restrepo, Andrés; Ortiz-Fonseca, Martha; Latorre-Santos, Catalina; Pardo-Oviedo, Juan Mauricio

    2018-01-01

    ABSTRACT The relationship between students’ withdrawal and educational variables has generated a considerable number of publications. As the explosion of information in sciences and integration theories led to creating different curriculum designs, it has been assumed that differences among designs explain academic success and, therefore, students’ retention. However, little attention has been given to examine explicitly how diverse designs influence dropout rates in practice, which questions if decisions to reform curricula are sufficiently informed. This article describes our curriculum reform, which exposes our former and current curriculum designs as having had dissimilar dropout percentages. Furthermore, we aimed to explore the influence of different curriculum designs on students’ dropout rates. The conclusion is that dropout variations may be explained not only because of the curriculum design itself, but also because of the power relationship changes between teachers and students that brought out the design change. Consequently, more research is needed to fully understand the political implications of different curriculum designs and their influence on dropout rates. PMID:29392996

  16. High School Dropout in Proximal Context: The Triggering Role of Stressful Life Events.

    Science.gov (United States)

    Dupéré, Véronique; Dion, Eric; Leventhal, Tama; Archambault, Isabelle; Crosnoe, Robert; Janosz, Michel

    2018-03-01

    Adolescents who drop out of high school experience enduring negative consequences across many domains. Yet, the circumstances triggering their departure are poorly understood. This study examined the precipitating role of recent psychosocial stressors by comparing three groups of Canadian high school students (52% boys; M age  = 16.3 years; N = 545): recent dropouts, matched at-risk students who remain in school, and average students. Results indicate that in comparison with the two other groups, dropouts were over three times more likely to have experienced recent acute stressors rated as severe by independent coders. These stressors occurred across a variety of domains. Considering the circumstances in which youth decide to drop out has implications for future research and for policy and practice. © 2017 The Authors. Child Development © 2017 Society for Research in Child Development, Inc.

  17. A Systematic Review and Meta-Analysis Estimating the Expected Dropout Rates in Randomized Controlled Trials on Yoga Interventions.

    Science.gov (United States)

    Cramer, Holger; Haller, Heidemarie; Dobos, Gustav; Lauche, Romy

    2016-01-01

    A reasonable estimation of expected dropout rates is vital for adequate sample size calculations in randomized controlled trials (RCTs). Underestimating expected dropouts rates increases the risk of false negative results while overestimating rates results in overly large sample sizes, raising both ethical and economic issues. To estimate expected dropout rates in RCTs on yoga interventions, MEDLINE/PubMed, Scopus, IndMED, and the Cochrane Library were searched through February 2014; a total of 168 RCTs were meta-analyzed. Overall dropout rate was 11.42% (95% confidence interval [CI] = 10.11%, 12.73%) in the yoga groups; rates were comparable in usual care and psychological control groups and were slightly higher in exercise control groups (rate = 14.53%; 95% CI = 11.56%, 17.50%; odds ratio = 0.82; 95% CI = 0.68, 0.98; p = 0.03). For RCTs with durations above 12 weeks, dropout rates in yoga groups increased to 15.23% (95% CI = 11.79%, 18.68%). The upper border of 95% CIs for dropout rates commonly was below 20% regardless of study origin, health condition, gender, age groups, and intervention characteristics; however, it exceeded 40% for studies on HIV patients or heterogeneous age groups. In conclusion, dropout rates can be expected to be less than 15 to 20% for most RCTs on yoga interventions. Yet dropout rates beyond 40% are possible depending on the participants' sociodemographic and health condition.

  18. A Systematic Review and Meta-Analysis Estimating the Expected Dropout Rates in Randomized Controlled Trials on Yoga Interventions

    Directory of Open Access Journals (Sweden)

    Holger Cramer

    2016-01-01

    Full Text Available A reasonable estimation of expected dropout rates is vital for adequate sample size calculations in randomized controlled trials (RCTs. Underestimating expected dropouts rates increases the risk of false negative results while overestimating rates results in overly large sample sizes, raising both ethical and economic issues. To estimate expected dropout rates in RCTs on yoga interventions, MEDLINE/PubMed, Scopus, IndMED, and the Cochrane Library were searched through February 2014; a total of 168 RCTs were meta-analyzed. Overall dropout rate was 11.42% (95% confidence interval [CI] = 10.11%, 12.73% in the yoga groups; rates were comparable in usual care and psychological control groups and were slightly higher in exercise control groups (rate = 14.53%; 95% CI = 11.56%, 17.50%; odds ratio = 0.82; 95% CI = 0.68, 0.98; p=0.03. For RCTs with durations above 12 weeks, dropout rates in yoga groups increased to 15.23% (95% CI = 11.79%, 18.68%. The upper border of 95% CIs for dropout rates commonly was below 20% regardless of study origin, health condition, gender, age groups, and intervention characteristics; however, it exceeded 40% for studies on HIV patients or heterogeneous age groups. In conclusion, dropout rates can be expected to be less than 15 to 20% for most RCTs on yoga interventions. Yet dropout rates beyond 40% are possible depending on the participants’ sociodemographic and health condition.

  19. Dropout rates and factors associated with dropout from treatment among elderly patients attending the outpatient services of a tertiary care hospital.

    Science.gov (United States)

    Grover, Sandeep; Dua, Devakshi; Chakrabarti, Subho; Avasthi, Ajit

    2018-01-01

    This study aimed to evaluate the "dropout" rates from treatment and associated factors among elderly patients attending a tertiary care psychiatry outpatient facility. Data of 1422 patients aged ≥60 years, attending the walk-in clinic were evaluated. Out of 1422 patients, 406 (28.55%) belonged to the "dropout" group. In the "dropout" group, the age of patients was significantly higher than the followed-up group, and a higher proportion of patients were >70 years old. Significantly lower proportion of patients with diagnosis of depressive disorders belonged to the "dropout" group and significantly higher proportion of patients with "other" diagnoses belonged to the dropped out group. In patients with depressive disorders, a higher proportion of the patients in the "dropout" group were Hindu by religion (68.7% vs. 58.7%; χ 2 = 4.26; P = 0.03). In patients with bipolar disorder, patients in the "dropout" group had significantly higher income (Rs. 13,323 [standard deviation [SD] = 16,769] vs. 5681 [SD = 9422]; t -test value: 2-25; P = 0.028) and lesser proportion of patients were of the male gender (63.15 vs. 86.95%; Mann-Whitney U value = 257.5; P = 0.039). In the group of other diagnoses, a higher proportion of patients in the "dropout" group were currently single (32.3% vs. 18.7%; χ 2 = 4.12; P = 0.042), from rural locality (63.1% vs. 46.72%; χ 2 = 4.33; P = 0.037) and were not prescribed medications (40% vs. 22.4%; χ 2 = 6.05; P = 0.04). Dropout from treatment among elderly patients is associated with higher age, not being prescribed medications, and diagnosis other than the affective disorders, psychotic disorders, and the cognitive disorders.

  20. Alaskan Native High School Dropouts: A Report Prepared for Project ANNA.

    Science.gov (United States)

    Jacobson, Desa

    Presented is a summary of the Alaskan Native high school dropouts. The data collected on 180 Native Alaskan high school dropouts was taken from the regional dormitories at Nome, Kodiak, Bethel and Boarding Home programs in Anchorage, Tok, Fairbanks, Dillingham, and Ketchikan. Students who terminated for academic reasons, failed to attend school,…

  1. How Many Central City High Schools Have A Severe Dropout Problem, Where Are They Located, and Who Attends Them? Initial Estimates Using the Common Core of Data

    OpenAIRE

    Balfanz, Robert; Legters, Nettie

    2001-01-01

    The analysis presented in this paper strongly suggests that about half of the high schools in the nation’s 35 largest cities have severe dropout rates. It further shows that high schools with weak promoting power and by implication high dropout rates are found in almost all of the largest cities but they are particularly concentrated in Midwestern and Northern industrial cities and Texas.

  2. Do School Budgets Matter? The Effect of Budget Referenda on Student Dropout Rates

    Science.gov (United States)

    Lee, Kyung-Gon; Polachek, Solomon W.

    2018-01-01

    This paper analyzes how changes in school expenditures affect dropout rates based on data from 466 school districts in New York during the 2003/04 to the 2007/08 school years. Past traditional regression approaches show mixed results in part because school expenditures are likely endogenous, so that one cannot disentangle cause and effect. The…

  3. Dropout and Functional Illiteracy Rates in Central Appalachia. Appalachian Data Bank Report #1.

    Science.gov (United States)

    Crew, B. Keith; And Others

    Computerized analysis of 1980 Census data documented educational deficiencies in 85 Central Appalachian counties of Kentucky, Tennessee, Virginia, and West Virginia. Dropout rates among youth ages 16-19 were found to be higher in Central Appalachian counties than in non-Central Appalachian counties, the poorest counties had the highest dropout…

  4. The Effects of the Introduction of Bachelor Degrees on College Enrollment and Dropout Rates

    Science.gov (United States)

    Horstschräer, Julia; Sprietsma, Maresa

    2015-01-01

    We estimate the short-term effects of the introduction of the Bachelor degree system in Germany, a change in degree regulations such that students need less time to earn a first degree, on college enrollment and dropout rates. We use variation in the timing of the reform at the university department level to identify the effects of the reform…

  5. Development of a Program to Reduce Dropout Rates of Pregnant and Parenting Teens.

    Science.gov (United States)

    Pollack, Andrew M.

    1987-01-01

    Describes a program to reduce the dropout rate for pregnant and parenting teens at York Vocational-Technical School (Pennsylvania) for the second semester of 1985-86. One successful feature was a "caring class" providing information about pregnancy, childcare, nutrition, and other subjects. The program retained most of its enrollees. Includes 1…

  6. Freshman Year Dropouts: Interactions between Student and School Characteristics and Student Dropout Status

    Science.gov (United States)

    Zvoch, Keith

    2006-01-01

    Data from a large school district in the southwestern United States were analyzed to investigate relations between student and school characteristics and high school freshman dropout patterns. Application of a multilevel logistic regression model to student dropout data revealed evidence of school-to-school differences in student dropout rates and…

  7. Student Dropout from the Perspectives of Junior High Counselors in Northeast Mississippi

    Science.gov (United States)

    Bennett, Kelly Ann

    2013-01-01

    I investigated fifteen junior high counselors' understandings about student dropout, particularly about identification of and interventions for students at risk for dropping out of school. As an educator, I desired to research the phenomenon of student dropout to understand how to better reach these types of students. Research is available…

  8. Stressors and Turning Points in High School and Dropout: A Stress Process, Life Course Framework

    Science.gov (United States)

    Dupéré, Véronique; Leventhal, Tama; Dion, Eric; Crosnoe, Robert; Archambault, Isabelle; Janosz, Michel

    2015-01-01

    High school dropout is commonly seen as the result of a long-term process of failure and disengagement. As useful as it is, this view has obscured the heterogeneity of pathways leading to dropout. Research suggests, for instance, that some students leave school not as a result of protracted difficulties but in response to situations that emerge…

  9. Is the Glass Half Empty or Half Full? Enrollment, Graduation, and Dropout Rates in Latin America

    OpenAIRE

    Marina Bassi; Matias Busso; Juan Sebastián Muñoz

    2014-01-01

    We use 292 household surveys from 18 Latin American countries to document patterns in secondary school graduation rates over the period 1990-2010. We find that enrollment and graduation rates increased during that period while dropout rates decreased. We provide two types of explanations for these patterns. Countries implemented changes on the supply side to increase access, by increasing the resources allocated to education and designing policies to help students staying in school. Despite t...

  10. Evaluation of a Public Awareness Campaign to Prevent High School Dropout.

    Science.gov (United States)

    Babinski, Leslie M; Corra, Ashley J; Gifford, Elizabeth J

    2016-08-01

    Many advocacy organizations devote time and resources to increasing community awareness and educating the public in an effort to gain support for their issue. One such effort, the Dropout Prevention Campaign by America's Promise Alliance, aimed to increase the visibility of the high school dropout problem and mobilize the community to take action. The objective of this paper is to evaluate the framing of the Dropout Prevention Campaign in television news media. To evaluate this campaign, television news coverage about high school dropout in 12 U.S. communities (N = 982) was examined. A content analysis of news transcripts was conducted and coded to determine the definition of the problem, the reasons for dropout and the possible solutions. Findings indicated that the high school dropout problem was most often framed (30 % of news segments) in terms of the economic and societal implications for the community. Individual student factors as well as broader societal influences were frequently discussed as possible reasons for dropout. The most commonly mentioned solutions were school-based interventions. News segments that mentioned America's Promise Alliance were more likely to frame the issue as a crisis and to use statistics to illustrate that point. Solutions that were more likely to appear in America's Promise segments promoted community and cross-sector involvement, consistent with the messages promoted by the Dropout Prevention Campaign. The findings suggest that a media content analysis can be an effective framework for analyzing a prevention campaign.

  11. Switching Schools: Reconsidering the Relationship Between School Mobility and High School Dropout

    Science.gov (United States)

    Gasper, Joseph; DeLuca, Stefanie; Estacion, Angela

    2014-01-01

    Youth who switch schools are more likely to demonstrate a wide array of negative behavioral and educational outcomes, including dropping out of high school. However, whether switching schools actually puts youth at risk for dropout is uncertain, since youth who switch schools are similar to dropouts in their levels of prior school achievement and engagement, which suggests that switching schools may be part of the same long-term developmental process of disengagement that leads to dropping out. Using data from the National Longitudinal Survey of Youth 1997, this study uses propensity score matching to pair youth who switched high schools with similar youth who stayed in the same school. We find that while over half the association between switching schools and dropout is explained by observed characteristics prior to 9th grade, switching schools is still associated with dropout. Moreover, the relationship between switching schools and dropout varies depending on a youth's propensity for switching schools. PMID:25554706

  12. Drop-out and admission cancel rate among the students in a selected medical college.

    Science.gov (United States)

    Wahed, F; Latif, S A; Mahamud, M M; Nessa, A; Hossain, M A; Sultana, S Z; Hossain, M B

    2011-04-01

    A record based descriptive type of study was carried out among the under-graduate students of Mymensingh Medical College from the session 1966-67 to 2006-07. The academic years were divided into four decades and admission was followed into three categories such as retained, cancellation and drop-out. Total number of the students was 5892. Among them 3848(65.30%) were male and 2044(34.69%) were female. Out of 5892 students drop-out was 282(4.78%) and admission cancel was 304(5.15%). It was also found that drop-out in male was 232(6.02%) and in female was 50(2.44%) and admission cancel in male was 266(5.87%) and in female was 78(3.81%). The difference was found statistically significant (pcancel rate is decreasing from the very beginning to till now. It was also observed that all drop-out and admission cancellation were in first & second year students. There was no continuation of their class roll numbers in third year registration.

  13. A Bayesian encourages dropout

    OpenAIRE

    Maeda, Shin-ichi

    2014-01-01

    Dropout is one of the key techniques to prevent the learning from overfitting. It is explained that dropout works as a kind of modified L2 regularization. Here, we shed light on the dropout from Bayesian standpoint. Bayesian interpretation enables us to optimize the dropout rate, which is beneficial for learning of weight parameters and prediction after learning. The experiment result also encourages the optimization of the dropout.

  14. Impact of Dupoto-e-Maa education project on dropout rate and academic performance

    Directory of Open Access Journals (Sweden)

    James B. Ouda

    2016-09-01

    Conclusion: The study recommended that there is need to increase the number of non-governmental organisations modelled around the Dupoto-e-Maa education project so as to reduce dropout rate and improve pupil academic performance. The findings could also inform government policy in terms of recruitment and placement of teachers in schools in arid and semi-arid lands. Project funding could be increased to improve visibility and sustainability of project activities.

  15. The Causes of Dropout in Rural Primary Schools in Malawi

    OpenAIRE

    谷口, 京子

    2017-01-01

    High dropout rates is a critical issue in most of developing countries. Malawi follows this trend of student nonpersistence; in 2013, the primary school dropout rate was approximately 12.2%.This study aims to find the causes of dropout in rural Malawian primary schools. There are two features: data were collected through survival analysis, which has been used to study dropout in developed countries; a multilevel logistic regression was used to classify individual, family, teacher and school f...

  16. RESEARCH ANALYSIS ON MOOC COURSE DROPOUT AND RETENTION RATES

    Directory of Open Access Journals (Sweden)

    Marcela Gerogina GOMEZ-ZERMENO

    2016-04-01

    Full Text Available This research’s objective was to identify the terminal efficiency of the Massive Online Open Course “Educational Innovation with Open Resources” offered by a Mexican private university. A quantitative methodology was used, combining descriptive statistics and probabilistic models to analyze the levels of retention, completion, and desertion, as well as the characteristics of the students who completed the course. The results show a 14% of student retention and an 11.7% of student completion, relative to the total number of participants, who had some common characteristics: having a graduate (master or doctorate, being experienced in online education, committed to the course and self-taught. The participants who abandoned the course expressed the following reasons: problems with the course’s structure, limitations in the use of information and communication technologies or limited English proficiency, family reasons or low time disposition. It is recommended to take actions that will increase the knowledge in order to explain the MOOCs’ desertion rates and to strengthen their structures to improve the retention and completion rates.

  17. Cigarette Smoking Trajectories From Sixth to Twelfth Grade: Associated Substance Use and High School Dropout.

    Science.gov (United States)

    Orpinas, Pamela; Lacy, Beth; Nahapetyan, Lusine; Dube, Shanta R; Song, Xiao

    2016-02-01

    The purpose of this longitudinal study was to identify distinct trajectories of cigarette smoking from sixth to twelfth grade and to characterize these trajectories by use of other drugs and high school dropout. The diverse sample for this analysis consisted of a cohort of 611 students from Northeast Georgia who participated in the Healthy Teens Longitudinal Study (2003-2009). Students completed seven yearly assessments from sixth through twelfth grade. We used semi-parametric, group-based modeling to identify groups of students whose smoking behavior followed a similar progression over time. Current smoking (past 30 day) increased from 6.9% among sixth graders to 28.8% among twelfth graders. Four developmental trajectories of cigarette smoking were identified: Abstainers/Sporadic Users (71.5% of the sample), Late Starters (11.3%), Experimenters (9.0%), and Continuous Users (8.2%). The Abstainer/Sporadic User trajectory was composed of two distinct groups: those who never reported any tobacco use (True Abstainers) and those who reported sporadic, low-level use (Sporadic Users). The True Abstainers reported significantly less use of alcohol and other drugs and lower dropout rates than students in all other trajectories, and Sporadic Users had worse outcomes than True Abstainers. Experimenters and Continuous Users reported the highest drug use. Over one-third of Late Starters (35.8%) and almost half of Continuous Users (44.4%) dropped out of high school. Cigarette smoking was associated with behavioral and academic problems. Results support early and continuous interventions to reduce use of tobacco and other drugs and prevent high school dropout. © The Author 2015. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  18. Dropout rates in medical students at one school before and after the installation of admission tests in Austria.

    Science.gov (United States)

    Reibnegger, Gilbert; Caluba, Hans-Christian; Ithaler, Daniel; Manhal, Simone; Neges, Heide Maria; Smolle, Josef

    2011-08-01

    Admission to medical studies in Austria since academic year 2005-2006 has been regulated by admission tests. At the Medical University of Graz, an admission test focusing on secondary-school-level knowledge in natural sciences has been used for this purpose. The impact of this important change on dropout rates of female versus male students and older versus younger students is reported. All 2,860 students admitted to the human medicine diploma program at the Medical University of Graz from academic years 2002-2003 to 2008-2009 were included. Nonparametric and semiparametric survival analysis techniques were employed to compare cumulative probability of dropout between demographic groups. Cumulative probability of dropout was significantly reduced in students selected by active admission procedure versus those admitted openly (P students was only 0.145 (95% CI, 0.106-0.198). Among openly admitted students, but not for selected ones, the cumulative probabilities for dropout were higher for females (P students (P dropout hazard is highest during the second year of study. The introduction of admission testing significantly decreased the cumulative probability for dropout. In openly admitted students a significantly higher risk for dropout was found in female students and in older students, whereas no such effects can be detected after admission testing. Future research should focus on the sex dependence, with the aim of improving success rates among female applicants on the admission tests.

  19. A Review of Recruitment, Adherence and Drop-Out Rates in Omega-3 Polyunsaturated Fatty Acid Supplementation Trials in Children and Adolescents

    NARCIS (Netherlands)

    Van der Wurff, Inge; Meyer, Barbara; De Groot, Renate

    2017-01-01

    Introduction: The influence of n-3 long-chain polyunsaturated fatty acids (n-3 LCPUFA) supplementation on health outcomes has been studied extensively with randomized controlled trials (RCT). In many research fields, difficulties with recruitment, adherence and high drop-out rates have been

  20. Reasons for Dropout for Vocational High School Students

    Science.gov (United States)

    Tas, Ali; Selvitopu, Abdullah; Bora, Veysel; Demirkaya, Yusuf

    2013-01-01

    This study aimed to determine the reasons for dropout for persons who have not completed vocational education programme and left school without a diploma. By using snowball sampling method, 19 persons, willing to participate in the study, were reached. Data were obtained by semi structured interview forms. In data analysis process, inductive…

  1. Building a Grad Nation: Progress and Challenge in Ending the High School Dropout Epidemic. Annual Update, 2013

    Science.gov (United States)

    Balfanz, Robert; Bridgeland, John M.; Bruce, Mary; Fox, Joanna Hornig

    2013-01-01

    This fourth annual update on America's high school dropout crisis shows that for the first time the nation is on track to meet the goal of a 90 percent high school graduation rate by the Class of 2020--if the pace of improvement from 2006 to 2010 is sustained over the next 10 years. The greatest gains have occurred for the students of color and…

  2. Relationship of dropout and psychopathology in a high school sample in Mexico.

    Science.gov (United States)

    Chalita, Pablo J; Palacios, Lino; Cortes, Jose F; Landeros-Weisenberger, Angeli; Panza, Kaitlyn E; Bloch, Michael H

    2012-01-01

    School dropout has significant consequences for both individuals and societies. Only 21% of adults in Mexico achieve the equivalent of a high school education. We examined the relationship between school dropout and self-reported psychiatric symptoms in a middle school in a suburb of Mexico City. We used binomial logistic regression to examine the odds ratio (OR) of school dropout associated with students' self-reported psychopathology. Two-hundred thirty-seven students participated in the study. Psychosis [OR = 8.0 (95% confidence interval, CI: 1.7-37.2)], depression [OR = 4.7 (95% CI: 2.2-9.7)], tic disorders [OR = 3.7 (95% CI: 1.4-9.5)], ADHD [OR = 3.2 (95% CI: 1.5-6.4)], and social phobia [OR = 2.6 (95% CI: 1.2-5.8)] were associated with increased risk of school dropout after controlling for age and gender as covariates. Our study suggested that students' self-reported psychopathology is associated with increased school dropout in Mexico. ADHD and depression may be particularly useful childhood psychiatric disorders to target with public health interventions because they explain the greatest amount of the variance in school dropout of child psychiatric disorders.

  3. Reducing the drop-out rate of a technical oriented course by introducing Problem Based Learning – a first concept

    Directory of Open Access Journals (Sweden)

    Christian Kaufmann

    2011-04-01

    Full Text Available At the University of Applied Sciences (UAS Technikum Wien one of the most difficult courses in the Bachelor degree program of Computer Science is “Database Systems and Database Design”. Together with “Advanced Computer Programming”, this course accounts for the high drop-out rate in the degree program. For this reason, this course was chosen for a redesign, in line with the research project QUADRO (Measures to increase quality of teaching and to reduce drop-out rates promoted by the City of Vienna – MA 27 (EU strategy and promote economic development. As the authors have already gained experience in Problem Based Learning (PBL, they saw an opportunity to improve students’ database knowledge by changing the teaching method to Problem Based Learning (PBL. The proposed paper first explains the current situation, identifies its drawbacks and difficulties. In a second step, it describes the new method, shows the students’ feedback after the first semester and the resulting changes in the concept.

  4. Factors predicting dropout in student nursing assistants

    DEFF Research Database (Denmark)

    Svensson, Annemarie Lyng; Strøyer, Jesper; Ebbehøj, Niels Erik

    2008-01-01

    BACKGROUND: The dropout rate among student nursing assistants (NAs) in Danish health and social care education is high at >20%. AIMS: To explore if recent low back pain (LBP) history is a predictor of dropout among NA students, taking into account conventional risk factors for LBP, general health...

  5. Effective Dropout Prevention Strategies Developed by the High/Scope Educational Research Foundation.

    Science.gov (United States)

    Stellar, Arthur

    2002-01-01

    Introduces a collection of papers that address the High/Scope Foundation's approach to risk reduction and dropout prevention. Examines High/Scope's history and describes various High/Scope efforts (e.g., the Michigan School Readiness Program Evaluation, preschool and elementary curriculum development and training, movement and music curriculum…

  6. The Effects of Runaway-Homeless Episodes on High School Dropout

    Science.gov (United States)

    Aratani, Yumiko; Cooper, Janice L.

    2015-01-01

    This article uses data from the National Longitudinal Survey of Youth 1997 to examine the relationship between running away from home between the ages of 12 and 14 and dropping from high school among youth. Propensity score matching was conducted in estimating the effect of running away on high school dropout while controlling for confounding…

  7. Building a Grad Nation: Progress and Challenge in Ending the High School Dropout Epidemic. Annual Update, 2010-2011

    Science.gov (United States)

    Balfanz, Robert; Bridgeland, John M.; Fox, Joanna Hornig; Moore, Laura A.

    2011-01-01

    America continues to make progress in meeting its high school dropout challenge. Leaders in education, government, nonprofits and business have awakened to the individual, social and economic costs of the dropout crisis and are working together to solve it. This year, all states, districts, and schools are required by law to calculate high school…

  8. Reducing routine vaccination dropout rates: evaluating two interventions in three Kenyan districts, 2014.

    Science.gov (United States)

    Haji, Adam; Lowther, S; Ngan'ga, Z; Gura, Z; Tabu, C; Sandhu, H; Arvelo, Wences

    2016-02-16

    Globally, vaccine preventable diseases are responsible for nearly 20% of deaths annually among children education [Odds Ratio (OR) 1.8, 95% Confidence Interval (CI) 1.1-3.2], and residing >5 km from health facility (OR 1.6, CI 1.0-2.7) were associated with higher odds of dropping out. Those who received text messages were less likely to drop out compared to controls (OR 0.2, CI 0.04-0.8). There was no statistical difference between those who received stickers and controls (OR 0.9, CI 0.5-1.6). Text message reminders can reduce vaccination dropout rates in Kenya. We recommend the extended implementation of text message reminders in routine vaccination services.

  9. Reducing routine vaccination dropout rates: evaluating two interventions in three Kenyan districts, 2014

    Directory of Open Access Journals (Sweden)

    Adam Haji

    2016-02-01

    Full Text Available Abstract Background Globally, vaccine preventable diseases are responsible for nearly 20 % of deaths annually among children 5 km from health facility (OR 1.6, CI 1.0–2.7 were associated with higher odds of dropping out. Those who received text messages were less likely to drop out compared to controls (OR 0.2, CI 0.04–0.8. There was no statistical difference between those who received stickers and controls (OR 0.9, CI 0.5–1.6. Conclusion Text message reminders can reduce vaccination dropout rates in Kenya. We recommend the extended implementation of text message reminders in routine vaccination services.

  10. Examining the relationship between relative age, competition level, and dropout rates in male youth ice-hockey players.

    Science.gov (United States)

    Lemez, S; Baker, J; Horton, S; Wattie, N; Weir, P

    2014-12-01

    The relative age effect suggests that athletes born in the first two quartiles of a given selection year experience a selection advantage and therefore a greater opportunity for success. We describe two studies examining the relationship between relative age, competition level, and dropout rates of Ontario Minor Hockey Association male ice-hockey players from ages 10 to 15 years (n = 14 325). In Study 1, dropout was highest among players born in quartiles three and four [χ(2) (3) = 16.32, P < 0.05; w = 0.06], while Study 2 found dropped out players to have less movement between competition levels compared to retained players. This study confirms a relationship between relative age and dropout from ice-hockey and adds further depth to our understanding of this persistent phenomenon. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. High School Success: An Effective Intervention for Achievement and Dropout Prevention

    Science.gov (United States)

    Lowder, Christopher Michael

    2012-01-01

    The purpose of this mixed-design study was to use quantitative and qualitative research to explore the effects of High School Success (a course for at-risk ninth graders) and its effectiveness on student achievement, attendance, and dropout prevention. The research questions address whether there is a significant difference between at-risk ninth…

  12. High School Exit Exams and Dropout in an Era of Increased Accountability

    Science.gov (United States)

    Hemelt, Steven W.; Marcotte, Dave E.

    2013-01-01

    A key form of student-level accountability is the requirement for students to pass high school exit exams (HSEEs) in order to receive a diploma. In this paper, we examine the impact of HSEEs on dropout during a period when these exams became more common and rigorous. Further, we study whether offering alternate pathways to graduation for students…

  13. Dropout Prevention in Middle and High Schools: From Research to Practice

    Science.gov (United States)

    Wilkins, Julia; Bost, Loujeania Williams

    2016-01-01

    Based on work with state and local education agencies in dropout prevention for students with disabilities, successful research-based interventions are described along with details of how these interventions have been implemented in middle and high schools across the country. The interventions that have helped students with disabilities graduate…

  14. Relationships between Parenting Practices, Social Engagement, Academic Competency, and High School Dropout

    Science.gov (United States)

    Bedrossian, Alfred

    2017-01-01

    The purpose of this study was to investigate the relationships between parenting practices, social engagement, academic competency, and high school dropout. The study revealed students whose parents practiced Reactive Communication along with students that exhibited Truancy and Disciplinary Issues were more likely to drop out. Conversely, students…

  15. A Multidimensional Model of School Dropout from an 8-Year Longitudinal Study in a General High School Population

    Science.gov (United States)

    Fortin, Laurier; Marcotte, Diane; Diallo, Thierno; Potvin, Pierre; Royer, Egide

    2013-01-01

    This study tests an empirical multidimensional model of school dropout, using data collected in the first year of an 8-year longitudinal study, with first year high school students aged 12-13 years. Structural equation modeling analyses show that five personal, family, and school latent factors together contribute to school dropout identified at…

  16. The Effect of an Academic Dismissal Policy on Dropout, Graduation Rates and Student Satisfaction. Evidence from the Netherlands

    Science.gov (United States)

    Sneyers, Eline; De Witte, Kristof

    2017-01-01

    This paper examines the effect of the introduction of an academic dismissal (AD) policy (i.e. an intervention, which can lead to compulsory student withdrawal) on student dropout, student graduation rates and satisfaction with the study program. Using a difference-in-differences type of estimator, we compare programs that introduced an AD policy…

  17. The Link between Learning and Earning: A Comprehensive Service Delivery Model Designed To Improve the Quality of Life of High School Dropouts and "At-Risk" Youth.

    Science.gov (United States)

    Jackson, Cheryl D.

    Many youth face the following educational and economic barriers to success: (1) increased high school dropout rates; (2) adolescent pregnancy; (3) chronic unemployment; (4) poverty; (5) drug abuse; (6) suicide; and (7) crime and delinquency. The Atlantic Community College (New Jersey) Youth Corps Program, a successful conservation and service…

  18. Simulation of a Rapid Dropout Event for Highly Relativistic Electrons with the RBE Model

    Science.gov (United States)

    Kang, S-B.; Fok, M.-C.; Glocer, A.; Min, K.-W.; Choi, C.-R.; Choi, E.; Hwang, J.

    2016-01-01

    A flux dropout is a sudden and sizable decrease in the energetic electron population of the outer radiation belt on the time scale of a few hours. We simulated a flux dropout of highly relativistic 2.5 MeV electrons using the Radiation Belt Environment model, incorporating the pitch angle diffusion coefficients caused by electromagnetic ion cyclotron (EMIC) waves for the geomagnetic storm events of 23-26 October 2002. This simulation showed a remarkable decrease in the 2.5 MeV electron flux during main phase of the storm, compared to those without EMIC waves. This decrease was independent of magnetopause shadowing or drift loss to the magnetopause. We suggest that the flux decrease was likely to be primarily due to pitch angle scattering to the loss cone by EMIC waves. Furthermore, the 2.5 MeV electron flux calculated with EMIC waves correspond very well with that observed from Solar Anomalous and Magnetospheric Particle EXplorer spacecraft. EMIC wave scattering is therefore likely one of the key mechanisms to understand flux dropouts. We modeled EMIC wave intensities by the Kp index. However, the calculated dropout is a several hours earlier than the observed one. We propose that Kp is not the best parameter to predict EMIC waves.

  19. Factors that Contribute to Student Graduation and Dropout Rates: An In-Depth Study of a Rural Appalachian School District

    Science.gov (United States)

    Lyttle-Burns, Ann

    2011-01-01

    There has been a wealth of research conducted on the national epidemic of high school dropouts spanning several decades. It is estimated that the class of 2009 cost the nation $335 billion in lost wages, taxes and productivity over their lifetimes (Alliance for Excellent Education, 2009). The citizenry of the country suffers not only because of…

  20. Dropout in vocational education

    DEFF Research Database (Denmark)

    Jørgensen, Christian Helms

    For the last ten years drop out of vocational education has increased strongly in Denmark. Only half of the students, who take up a vocational programme on upper secondary level, complete it. Like in other European countries the low completion rates has caused considerable alarm on the political...... level (Lamb and Markussen 2011). Continuing high dropout rates will make it very hard for the government to reach its target for educational completion, and the government has launched a series of measures to increase retention including the obligation for all colleges to make plans for retention...... and monitor the progress in achieving the goals. The questions addressed in this paper are why and how dropout in VET takes place. The objective is to provide more detailed and qualified knowledge of the complex processes of dropping out....

  1. Can use of healthcare services among 15-16-year-olds predict an increased level of high school dropout? A longitudinal community study.

    Science.gov (United States)

    Homlong, Lisbeth; Rosvold, Elin O; Haavet, Ole R

    2013-09-19

    To study associations between healthcare seeking in 15-16-year-olds and high school dropout 5 years later. Longitudinal community study. Data from a comprehensive youth health survey conducted in 2000-2004, linked to data from national registries up to 2010. 13 964 10th grade secondary school students in six Norwegian counties. Logistic regression was used to compute ORs for high school dropout. The total proportion of students not completing high school 5 years after registering was 29% (girls 24%, boys 34%). Frequent attenders to school health services and youth health clinics at age 15-16 years had a higher dropout rate (37/48% and 45/71%), compared with those with no or moderate use. Adolescents referred to mental health services were also more likely to drop out (47/62%). Boys with moderate use of a general practitioner (GP) had a lower dropout rate (30%). A multiple logistic regression analysis, in which we adjusted for selected health indicators and sociodemographic background variables, revealed that seeking help from the youth health clinic and consulting mental health services, were associated with increased level of high school dropout 5 years later. Frequent attenders (≥4 contacts) had the highest odds of dropping out. Yet, boys who saw a GP and girls attending the school health services regularly over the previous year were less likely than their peers to drop out from high school. Adolescents who seek help at certain healthcare services can be at risk of dropping out of high school later. Health workers should pay particular attention to frequent attenders and offer follow-up when needed. However, boys who attended a GP regularly were more likely to continue to high school graduation, which may indicate a protective effect of having a regular and stable relationship with a GP.

  2. Drop-out rate among patients treated with omalizumab for severe asthma: Literature review and real-life experience.

    Science.gov (United States)

    Caminati, M; Senna, G; Stefanizzi, G; Bellamoli, R; Longhi, S; Chieco-Bianchi, F; Guarnieri, G; Tognella, S; Olivieri, M; Micheletto, C; Festi, G; Bertocco, E; Mazza, M; Rossi, A; Vianello, A

    2016-08-25

    In patients with asthma, particularly severe asthma, poor adherence to inhaled drugs negatively affects the achievement of disease control. A better adherence rate is expected in the case of injected drugs, such as omalizumab, as they are administered only in a hospital setting. However, adherence to omalizumab has never been systematically investigated. The aim of this study was to review the omalizumab drop-out rate in randomized controlled trials (RCTs) and real-life studies. A comparative analysis was performed between published data and the Italian North East Omalizumab Network (NEONet) database. In RCTs the drop-out rate ranged from 7.1 to 19.4 %. Although the reasons for withdrawal were only occasionally reported, patient decision and adverse events were the most frequently reported causes. In real-life studies the drop-out rate ranged from 0 to 45.5 %. In most cases lack of efficacy was responsible for treatment discontinuation. According to NEONet data, 32 % of treated patients dropped out, with an increasing number of drop outs observed over time. Patient decision and lack of efficacy accounted for most treatment withdrawals. Treatment adherence is particularly crucial in patients with severe asthma considering the clinical impact of the disease and the cost of non-adherence. The risk of treatment discontinuation has to be carefully considered both in the experimental and real-life settings. Increased knowledge regarding the main reasons for patient withdrawal is important to improve adherence in clinical practice.

  3. Leaving School and Its Outcomes on Health-related Fitness Among Drop-out Algerian High School Students

    Directory of Open Access Journals (Sweden)

    Mohammed Zerf

    2018-04-01

    Full Text Available Purpose. Schools are ideal venues for the implementation of healthy behaviors allied to the levels of physical activities as the physical and mental health correlate to psychosocial well-being of scholars. Whereas, this advantage is not reliable with dropout students. Support through psychological studies via time structure unconnected to self-efficacy relative to self-physical activity motivation among this social class, especially with the economic crisis as challenges imposed for Algerian society, concerning the high unemployment rates in line with high school dropouts. Method. This controlled study tested 104 high-school Male adolescent students aged around 17 years for academic years 2015–2016 and those under 18 years for academic years 2016–2017. Built on the ALPHA-Fitness test battery accompanied by questionnaire relevant to their physical and social time for both years. Results. Based on the design, the tests practised and the statistical processes applied within the search limitation, the results support, on one hand, the benefits of school venue as an ideal implementation of health and levels of physical activities and well-being among our scholars, and on the other, we confirmed the leaving school as a negative time trend via dropout students, poorly correlate with times physically and socially inactive. This study inspected that inactive lifestyle relate to body image disorders and disturbances concomitant to energy-expending relative to missing recreational time and sporting endeavours. Conclusions. Leaving school in the Algerian communities is a stress-related biological pathway that links physical disorders and depression virtual to social time structure proceeded to manage the relevant tasks, goals and objectives. Indicated in similar as best when individuals are clear about what it is they are expected to achieve.

  4. Dropout Rates in Randomized Clinical Trials of Antipsychotics: A Meta-analysis Comparing First- and Second-Generation Drugs and an Examination of the Role of Trial Design Features

    OpenAIRE

    Rabinowitz, Jonathan; Levine, Stephen Z.; Barkai, Orna; Davidov, Ori

    2008-01-01

    Dropout is often used as an outcome measure in clinical trials of antipsychotic medication. Previous research is inconclusive regarding (a) differences in dropout rates between first- and second-generation antipsychotic medications and (b) how trial design features reduce dropout. Meta-analysis of randomized controlled trials (RCTs) of antipsychotic medication was conducted to compare dropout rates for first- and second-generation antipsychotic drugs and to examine how a broad range of design...

  5. Biased Dropout and Crossmap Dropout: Learning towards effective Dropout regularization in convolutional neural network.

    Science.gov (United States)

    Poernomo, Alvin; Kang, Dae-Ki

    2018-08-01

    Training a deep neural network with a large number of parameters often leads to overfitting problem. Recently, Dropout has been introduced as a simple, yet effective regularization approach to combat overfitting in such models. Although Dropout has shown remarkable results on many deep neural network cases, its actual effect on CNN has not been thoroughly explored. Moreover, training a Dropout model will significantly increase the training time as it takes longer time to converge than a non-Dropout model with the same architecture. To deal with these issues, we address Biased Dropout and Crossmap Dropout, two novel approaches of Dropout extension based on the behavior of hidden units in CNN model. Biased Dropout divides the hidden units in a certain layer into two groups based on their magnitude and applies different Dropout rate to each group appropriately. Hidden units with higher activation value, which give more contributions to the network final performance, will be retained by a lower Dropout rate, while units with lower activation value will be exposed to a higher Dropout rate to compensate the previous part. The second approach is Crossmap Dropout, which is an extension of the regular Dropout in convolution layer. Each feature map in a convolution layer has a strong correlation between each other, particularly in every identical pixel location in each feature map. Crossmap Dropout tries to maintain this important correlation yet at the same time break the correlation between each adjacent pixel with respect to all feature maps by applying the same Dropout mask to all feature maps, so that all pixels or units in equivalent positions in each feature map will be either dropped or active during training. Our experiment with various benchmark datasets shows that our approaches provide better generalization than the regular Dropout. Moreover, our Biased Dropout takes faster time to converge during training phase, suggesting that assigning noise appropriately in

  6. Student Dropout Rates in Catalan Universities: Profile and Motives for Disengagement

    Science.gov (United States)

    Gairín, Joaquín; Triado, Xavier M.; Feixas, Mònica; Figuera, Pilar; Aparicio-Chueca, Pilar; Torrado, Mercedes

    2014-01-01

    Data from over 21,600 students who left Catalan higher education institutions during the academic years 2000-2001 and 2001-2002 have been analysed in order to describe the academic and personal profiles of university dropouts. Additionally, a telephone survey and face-to-face interviews with a pilot group of leavers were conducted to gather…

  7. Dropout Rates, Student Momentum, and Course Walls: A New Tool for Distance Education Designers

    Science.gov (United States)

    Christensen, Steven S.; Spackman, Jonathan S.

    2017-01-01

    This paper explores a new tool for instructional designers. By calculating and graphing the Student Momentum Indicator (M) for 196 university-level online courses and by employing the constant comparative method within the grounded theory framework, eight distinct graph shapes emerged as meaningful categories of dropout behavior. Several of the…

  8. Diabetes's 'health shock' to schooling and earnings: increased dropout rates and lower wages and employment in young adults.

    Science.gov (United States)

    Fletcher, Jason M; Richards, Michael R

    2012-01-01

    Despite a growing diabetes crisis, the nonmedical implications for young adults have gone virtually unexplored. We investigated the effects of diabetes on two key outcomes for this age group-schooling and earnings-and found that it delivers an increasingly common "health shock" to both. We identified effects in several measures of educational attainment, including a high school dropout rate that was six percentage points higher than among young adults without the disease. We also found lower employment and wages: A person with diabetes can conservatively expect to lose more than $160,000 over his or her working life, compared to a peer without the disease. For young adults with diabetes, having a parent with diabetes also leads to poorer outcomes than if one more parents do not have the disease-for example, reducing the likelihood of attending college by four to six percentage points, even after the child's health status is controlled for. These results highlight the urgency of attacking this growing health problem, as well as the need for measures such as in-school screening for whether diabetes's impact on individual learning and performance begins before the classic manifestations of clinical diabetes appear.

  9. Appropriateness of Dropout Layers and Allocation of Their 0.5 Rates across Convolutional Neural Networks for CIFAR-10, EEACL26, and NORB Datasets

    OpenAIRE

    Romanuke Vadim V.

    2017-01-01

    A technique of DropOut for preventing overfitting of convolutional neural networks for image classification is considered in the paper. The goal is to find a rule of rationally allocating DropOut layers of 0.5 rate to maximise performance. To achieve the goal, two common network architectures are used having either 4 or 5 convolutional layers. Benchmarking is fulfilled with CIFAR-10, EEACL26, and NORB datasets. Initially, series of all admissible versions for allocation of DropOut layers are ...

  10. Factors predicting dropout in student nursing assistants.

    Science.gov (United States)

    Svensson, Annemarie Lyng; Strøyer, Jesper; Ebbehøj, Niels Erik; Mortensen, Ole Steen

    2008-12-01

    The dropout rate among student nursing assistants (NAs) in Danish health and social care education is high at >20%. To explore if recent low back pain (LBP) history is a predictor of dropout among NA students, taking into account conventional risk factors for LBP, general health and physical fitness. Prospective study with 14-month follow-up (the duration of the education) in two schools of health and social care in the Region of Copenhagen, Denmark. Participants completed a comprehensive questionnaire, and their physical fitness (balance, back extension endurance, back flexion endurance and sagittal flexibility) was assessed at baseline. Dropout was defined as failure to complete NA education. A total of 790 subjects, 87% of those invited, completed the questionnaire; 612 subjects also completed the physical tests and were included in the present study and 500 (83%) were women. Recent LBP was not an independent predictor of school dropout. However, only among women who had LBP were other factors (a history of previous exposure to heavy physical workload, a low mental health score and failure to pass the back extension endurance test) associated with risk of dropout, OR (95% CI)=2.5 (1.2-5.3). Among men, only low height was significantly associated with dropout risk. A recent LBP history was not an independent single predictor of dropout from NA education but was a risk factor in combination with other factors.

  11. School motivation and high school dropout: the mediating role of educational expectation.

    Science.gov (United States)

    Fan, Weihua; Wolters, Christopher A

    2014-03-01

    A good deal of evidence indicates that students' motivational beliefs and attitudes play a critical role in their academic success. Research studies on how motivational factors may help determine whether students remain in high school or drop out, however, are relatively few. More specifically, there is a lack of research examining the dynamics of whether students' motivational beliefs from earlier in high school might be used to predict their status as a dropout in their final year. The aim of the present study was to examine the mediating role of students' educational expectations in linking students' school motivation to their dropout status by utilizing a nationally representative dataset. The present study used data from the Educational Longitudinal Study of 2002 (ELS: 2002). The final sample consisted of 16,194 students, with approximately 54% White, 13% Black, 16% Hispanic, and 10% Asian students, and the rest were Native American, Hawaiian, multiracial, or of other races. Structural equation modelling was employed to conduct the mediational analysis. The results of the present study demonstrated that the relationships between student ability beliefs in math and English and student behaviour of dropping out were fully mediated by students' educational expectations. The results also revealed that student intrinsic value in math and English had significant indirect relations with student behaviour of leaving school through students' educational expectations. The results of this study suggest that explanations for student dropout status that rely solely on students' social background and school behaviours without considering their motivation are incomplete. The study expands the extant research by showing possible pathways that motivate students to persist in high school. These pathways are specifically rooted in students' ability beliefs and intrinsic interest in learning through their relationships with students' expectations for their education. © 2012 The

  12. The Dropout Learning Algorithm

    Science.gov (United States)

    Baldi, Pierre; Sadowski, Peter

    2014-01-01

    Dropout is a recently introduced algorithm for training neural network by randomly dropping units during training to prevent their co-adaptation. A mathematical analysis of some of the static and dynamic properties of dropout is provided using Bernoulli gating variables, general enough to accommodate dropout on units or connections, and with variable rates. The framework allows a complete analysis of the ensemble averaging properties of dropout in linear networks, which is useful to understand the non-linear case. The ensemble averaging properties of dropout in non-linear logistic networks result from three fundamental equations: (1) the approximation of the expectations of logistic functions by normalized geometric means, for which bounds and estimates are derived; (2) the algebraic equality between normalized geometric means of logistic functions with the logistic of the means, which mathematically characterizes logistic functions; and (3) the linearity of the means with respect to sums, as well as products of independent variables. The results are also extended to other classes of transfer functions, including rectified linear functions. Approximation errors tend to cancel each other and do not accumulate. Dropout can also be connected to stochastic neurons and used to predict firing rates, and to backpropagation by viewing the backward propagation as ensemble averaging in a dropout linear network. Moreover, the convergence properties of dropout can be understood in terms of stochastic gradient descent. Finally, for the regularization properties of dropout, the expectation of the dropout gradient is the gradient of the corresponding approximation ensemble, regularized by an adaptive weight decay term with a propensity for self-consistent variance minimization and sparse representations. PMID:24771879

  13. Mining Educational Data Using Classification to Decrease Dropout Rate of Students

    OpenAIRE

    Pal, Saurabh

    2012-01-01

    In the last two decades, number of Higher Education Institutions (HEI) grows rapidly in India. Since most of the institutions are opened in private mode therefore, a cut throat competition rises among these institutions while attracting the student to got admission. This is the reason for institutions to focus on the strength of students not on the quality of education. This paper presents a data mining application to generate predictive models for engineering student's dropout management. Gi...

  14. School Dropouts or Pushouts? Overcoming Barriers for the Right to Education. CREATE Pathways to Access. Research Monograph No. 40

    Science.gov (United States)

    Reddy, Anugula N.; Sinha, Shantha

    2010-01-01

    Persistently high dropout rates are one of the biggest challenges to fulfilling the right to education in India. This paper attempts to assess the magnitude of the problem of dropout. The paper critically reviews the evidence on some of the commonly cited reasons for dropout, including poverty, limited to access to credit, child labour, and…

  15. Supervisors' perspective on medical thesis projects and dropout rates: survey among thesis supervisors at a large German university hospital.

    Science.gov (United States)

    Can, Elif; Richter, Felicitas; Valchanova, Ralitsa; Dewey, Marc

    2016-10-14

    To identify underlying causes for failure of medical thesis projects and the constantly high drop-out rate in Germany from the supervisors' perspective and to compare the results with the students' perspective. Cross-sectional survey. Online questionnaire for survey of medical thesis supervisors among the staff of Charité-Universitätsmedizin Berlin, Germany. Published, earlier longitudinal survey among students for comparison. 1069 thesis supervisors participated. Data are presented using descriptive statistics, and the χ 2 test served to compare the results among supervisors with the earlier data from the longitudinal survey of doctoral students. Not applicable. This survey is an observational study. Of 3653 potential participants, 1069 (29.3%) supervising 3744 doctoral candidates participated in the study. Supervisors considered themselves to be highly motivated and to offer adequate supervision. On the other hand, 87% stated that they did not feel well prepared for thesis supervision. Supervisors gave lack of timeliness of doctoral students and personal differences (p=0.024 and p=0.001) as the main reasons for terminating thesis projects. Doctoral students predominantly mentioned methodological problems and difficult subjects as critical issues (p=0.001 and pthesis supervisors and medical students feel ill prepared for their roles in the process of a medical dissertation. Contradictory reasons for terminating medical thesis projects based on supervisors' and students' self-assessment suggest a lack of communication and true scientific collaboration between supervisors and doctoral students as the major underlying issue that requires resolution. 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/.

  16. How Did Successful High Schools Improve Their Graduation Rates?

    Science.gov (United States)

    Robertson, Janna Siegel; Smith, Robert W.; Rinka, Jason

    2016-01-01

    The researchers surveyed 23 North Carolina high schools that had markedly improved their graduation rates over the past five years. The administrators reported on the dropout prevention practices and programs to which they attributed their improved graduation rates. The majority of schools reported policy changes, especially with suspension. The…

  17. High school dropouts: Interactions between social context, self-perceptions, school engagement, and student dropout☆

    Science.gov (United States)

    Fall, Anna-Mária; Roberts, Greg

    2012-01-01

    Research suggests that contextual, self-system, and school engagement variables influence dropping out from school. However, it is not clear how different types of contextual and self-system variables interact to affect students’ engagement or contribute to decisions to dropout from high school. The self-system model of motivational development represents a promising theory for understanding this complex phenomenon. The self-system model acknowledges the interactive and iterative roles of social context, self-perceptions, school engagement, and academic achievement as antecedents to the decision to dropout of school. We analyzed data from the Education Longitudinal Study of 2002–2004 in the context of the self-system model, finding that perception of social context (teacher support and parent support) predicts students’ self-perceptions (perception of control and identification with school), which in turn predict students’ academic and behavioral engagement, and academic achievement. Further, students’ academic and behavioral engagement and achievement in 10th grade were associated with decreased likelihood of dropping out of school in 12th grade. PMID:22153483

  18. Appropriateness of Dropout Layers and Allocation of Their 0.5 Rates across Convolutional Neural Networks for CIFAR-10, EEACL26, and NORB Datasets

    Directory of Open Access Journals (Sweden)

    Romanuke Vadim V.

    2017-12-01

    Full Text Available A technique of DropOut for preventing overfitting of convolutional neural networks for image classification is considered in the paper. The goal is to find a rule of rationally allocating DropOut layers of 0.5 rate to maximise performance. To achieve the goal, two common network architectures are used having either 4 or 5 convolutional layers. Benchmarking is fulfilled with CIFAR-10, EEACL26, and NORB datasets. Initially, series of all admissible versions for allocation of DropOut layers are generated. After the performance against the series is evaluated, normalized and averaged, the compromising rule is found. It consists in non-compactly inserting a few DropOut layers before the last convolutional layer. It is likely that the scheme with two or more DropOut layers fits networks of many convolutional layers for image classification problems with a plenty of features. Such a scheme shall also fit simple datasets prone to overfitting. In fact, the rule “prefers” a fewer number of DropOut layers. The exemplary gain of the rule application is roughly between 10 % and 50 %.

  19. Predicting dropout in outpatient dialectical behavior therapy with patients with borderline personality disorder receiving psychiatric disability.

    Science.gov (United States)

    Landes, Sara J; Chalker, Samantha A; Comtois, Katherine Anne

    2016-01-01

    Rates of treatment dropout in outpatient Dialectical Behavior Therapy (DBT) in the community can be as high as 24 % to 58 %, making dropout a great concern. The primary purpose of this article was to examine predictors of dropout from DBT in a community mental health setting. Participants were 56 consumers with borderline personality disorder (BPD) who were psychiatrically disabled participating in a larger feasibility trial of Dialectical Behavior Therapy- Accepting the Challenges of Exiting the System. The following variables were examined to see whether they predicted dropout in DBT: age, education level, baseline level of distress, baseline level of non-acceptance of emotional responses, and skills module in which a consumer started DBT skills group. These variables were chosen based on known predictors of dropout in consumers with BPD and in DBT, as well as an interest in what naturally occurring variables might impact dropout. The dropout rate in this sample was 51.8 %. Results of the logistic regression show that younger age, higher levels of baseline distress, and a higher level of baseline non-acceptance of emotional responses were significantly associated with dropout. The DBT skills module in which an individual started group did not predict dropout. The implications of these findings are that knowledge of consumer age and pretreatment levels of distress and non-acceptance of emotional responses can impact providers' choice of commitment and treatment strategies to reduce dropout. Future research should examine these strategies, as well as the impact of predictor variables on outcome and reasons for dropout.

  20. Performance of nonlinear mixed effects models in the presence of informative dropout.

    Science.gov (United States)

    Björnsson, Marcus A; Friberg, Lena E; Simonsson, Ulrika S H

    2015-01-01

    Informative dropout can lead to bias in statistical analyses if not handled appropriately. The objective of this simulation study was to investigate the performance of nonlinear mixed effects models with regard to bias and precision, with and without handling informative dropout. An efficacy variable and dropout depending on that efficacy variable were simulated and model parameters were reestimated, with or without including a dropout model. The Laplace and FOCE-I estimation methods in NONMEM 7, and the stochastic simulations and estimations (SSE) functionality in PsN, were used in the analysis. For the base scenario, bias was low, less than 5% for all fixed effects parameters, when a dropout model was used in the estimations. When a dropout model was not included, bias increased up to 8% for the Laplace method and up to 21% if the FOCE-I estimation method was applied. The bias increased with decreasing number of observations per subject, increasing placebo effect and increasing dropout rate, but was relatively unaffected by the number of subjects in the study. This study illustrates that ignoring informative dropout can lead to biased parameters in nonlinear mixed effects modeling, but even in cases with few observations or high dropout rate, the bias is relatively low and only translates into small effects on predictions of the underlying effect variable. A dropout model is, however, crucial in the presence of informative dropout in order to make realistic simulations of trial outcomes.

  1. Linking the Timing of Career and Technical Education Coursetaking with High School Dropout and College-Going Behavior

    Science.gov (United States)

    Gottfried, Michael A.; Plasman, Jay Stratte

    2018-01-01

    While prior studies have examined the efficacy of career and technical education (CTE) courses on high school students' outcomes, there is little knowledge on timing of these courses and a potential link to student outcomes. We asked if the timing of these courses predicted differences in the likelihood of dropout and on-time high school…

  2. Predicting Dropout Using Student- and School-Level Factors: An Ecological Perspective

    Science.gov (United States)

    Wood, Laura; Kiperman, Sarah; Esch, Rachel C.; Leroux, Audrey J.; Truscott, Stephen D.

    2017-01-01

    High school dropout has been associated with negative outcomes, including increased rates of unemployment, incarceration, and mortality. Dropout rates vary significantly depending on individual and environmental factors. The purpose of our study was to use an ecological perspective to concurrently explore student- and school-level predictors…

  3. Prediction of Student Dropout in E-Learning Program Through the Use of Machine Learning Method

    OpenAIRE

    Mingjie Tan; Peiji Shao

    2015-01-01

    The high rate of dropout is a serious problem in E-learning program. Thus it has received extensive concern from the education administrators and researchers. Predicting the potential dropout students is a workable solution to prevent dropout. Based on the analysis of related literature, this study selected student’s personal characteristic and academic performance as input attributions. Prediction models were developed using Artificial Neural Network (ANN), Decision Tree (DT) and Bayesian Ne...

  4. Problems and Strategies Regarding Reducing America's Migrant Student Dropout Rate. Congressional Testimony Delivered in Response to a Request from the National Commission on Migrant Education.

    Science.gov (United States)

    Helge, Doris

    Studies conducted by the National Rural Development Institute (NRDI) indicate that migrant students have a higher school dropout rate than non-migrant students. In addition, rural migrant students experience higher levels of family dysfunction and abuse, teen pregnancy, emotional difficulties such as depression or low self-esteem, poverty,…

  5. Selected determinants may account for dropout risks among medical students.

    Science.gov (United States)

    Mørcke, Anne Mette; O'Neill, Lotte; Kjeldsen, Inge Trads; Eika, Berit

    2012-09-01

    The dropout level from the Danish medical schools is high, but we have only little insight into this problem. The purpose of this study was to qualify the ongoing discussions concerning dropout. In this retrospective cohort study, relevant variables were extracted from the established database of Aarhus University for the 639 students initiating medicine studies between 1 January 1999 and 31 December 2000. A multivariate pre-admission and post-admission model was examined. Of the 639 medical students, 20% dropped out. Most students dropped out during their first year. The type of admission exam was a strong predictor of dropout in the pre-admission model, whereas previous higher education protected against dropout. Obtaining leave was a very strong predictor of dropout in the post-admission model, whereas high grades protected against dropout. The dropout rate has been decreasing during the past decade. Young people considering studying medicine could be advised to choose natural science subjects in high school, and a number of research questions concerning preparedness for medical school are worth pursuing. Leave or very low grades during the first and second study years might serve as red flags to supervisors. Study research was funded by Aarhus University. Not relevant, register-based research with no biological human material cannot be notified to the Danish Committee System. The Danish Data Protection Agency allows schools to conduct anonymized, non-sensitive, educational analyses without notification.

  6. Primary Education and Dropout in Nepal

    Science.gov (United States)

    Devkota, Shree Prasad; Bagale, Shiba

    2015-01-01

    This article tries to highlight the dropout rate of primary education of Nepal. The main essence of the article is to explore the situation of dropout of primary education. There are several programs and policies to reduce the dropout, out of the school children and so on but still there are several issues that are left behind. Educational budget…

  7. Early Onset of Distress Disorders and High-School Dropout: Prospective Evidence From a National Cohort of Australian Adolescents.

    Science.gov (United States)

    Butterworth, Peter; Leach, Liana S

    2018-06-01

    Prior research examining whether depression and anxiety lead to high-school dropout has been limited by a reliance on retrospective reports, the assessment of mental health at a single point in time (often remote from the time of high-school exit), and the omission of important measures of the social and familial environment. The present study addressed these limitations by analyzing 8 waves of longitudinal data from a cohort of Australian adolescents (n = 1,057) in the Household, Income and Labor Dynamics in Australia (HILDA) Survey (2001-2008). Respondents were followed from the age of 15 years through completion of or exit from high school. Discrete-time survival analysis was used to assess whether the early experience of a distress disorder (indicated by scores dropout, after controlling for household and parental socioeconomic characteristics and for tobacco smoking and alcohol consumption. Adolescents with a prior distress disorder had twice the odds of high-school dropout compared with those without (odds ratio = 1.99, 95% confidence interval: 1.24, 3.17). This association was somewhat attenuated but remained significant in models including tobacco and alcohol consumption (odds ratio = 1.74, 95% confidence interval: 1.74; 1.09, 2.78). These results suggest that improving the mental health of high-school students may promote better educational outcomes.

  8. Predicting Dropout from Intensive Outpatient Cognitive Behavioural Therapy for Binge Eating Disorder Using Pre-treatment Characteristics: A Naturalistic Study.

    Science.gov (United States)

    Vroling, Maartje S; Wiersma, Femke E; Lammers, Mirjam W; Noorthoorn, Eric O

    2016-11-01

    Dropout rates in binge eating disorder (BED) treatment are high (17-30%), and predictors of dropout are unknown. Participants were 376 patients following an intensive outpatient cognitive behavioural therapy programme for BED, 82 of whom (21.8%) dropped out of treatment. An exploratory logistic regression was performed using eating disorder variables, general psychopathology, personality and demographics to identify predictors of dropout. Binge eating pathology, preoccupations with eating, shape and weight, social adjustment, agreeableness, and social embedding appeared to be significant predictors of dropout. Also, education showed an association to dropout. This is one of the first studies investigating pre-treatment predictors for dropout in BED treatment. The total explained variance of the prediction model was low, yet the model correctly classified 80.6% of cases, which is comparable to other dropout studies in eating disorders. Copyright © 2016 John Wiley & Sons, Ltd and Eating Disorders Association. Copyright © 2016 John Wiley & Sons, Ltd and Eating Disorders Association.

  9. An ultra-low power output capacitor-less low-dropout regulator with slew-rate-enhanced circuit

    Science.gov (United States)

    Cheng, Xin; Zhang, Yu; Xie, Guangjun; Yang, Yizhong; Zhang, Zhang

    2018-03-01

    An ultra-low power output-capacitorless low-dropout (LDO) regulator with a slew-rate-enhanced (SRE) circuit is introduced. The increased slew rate is achieved by sensing the transient output voltage of the LDO and then charging (or discharging) the gate capacitor quickly. In addition, a buffer with ultra-low output impedance is presented to improve line and load regulations. This design is fabricated by SMIC 0.18 μm CMOS technology. Experimental results show that, the proposed LDO regulator only consumes an ultra-low quiescent current of 1.2 μA. The output current range is from 10 μA to 200 mA and the corresponding variation of output voltage is less than 40 mV. Moreover, the measured line regulation and load regulation are 15.38 mV/V and 0.4 mV/mA respectively. Project supported by the National Natural Science Foundation of China (Nos. 61401137, 61404043, 61674049).

  10. Predictors of dropout from community clinic child CBT for anxiety disorders.

    Science.gov (United States)

    Wergeland, Gro Janne H; Fjermestad, Krister W; Marin, Carla E; Haugland, Bente Storm-Mowatt; Silverman, Wendy K; Öst, Lars-Göran; Havik, Odd E; Heiervang, Einar R

    2015-04-01

    The aim was to investigate predictors of treatment dropout among 182 children (aged 8-15 years) participating in an effectiveness trial of manual-based 10-session individual and group cognitive behavior therapy (CBT) for anxiety disorders in community clinics. The dropout rate was 14.4%, with no significant difference between the two treatment conditions. We examined predictors for overall dropout (n=26), early (≤session 4, n=15), and late dropout (≥session 5, n=11). Overall dropout was predicted by low child and parent rated treatment credibility, and high parent self-rated internalizing symptoms. Low child rated treatment credibility predicted both early and late dropout. High parent self-rated internalizing symptoms predicted early dropout, whereas low parent rated treatment credibility predicted late dropout. These results highlight the importance of addressing treatment credibility, and to offer support for parents with internalizing symptoms, to help children and families remain in treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Risk Factors for School Dropout in a Sample of Juvenile Offenders

    Science.gov (United States)

    Fernández-Suárez, Asunción; Herrero, Juan; Pérez, Beatriz; Juarros-Basterretxea, Joel; Rodríguez-Díaz, Francisco J.

    2016-01-01

    Backgrounds: The high rates of school dropout worldwide and their relevance highlight the need for a close study of its causes and consequences. Literature has suggested that school dropout might be explained by multiple causes at different levels (individual, family, school, and neighborhood). The aim of the current study is to examine the relation between individual (defiant attitude, irresponsibility, alcohol abuse, and illegal drugs use), family (educational figure absent and parental monitoring), school factors (truancy and school conflict) and school dropout. Method: Judicial files of all juvenile offenders (218 males and 46 females) with a judicial penal measure in Asturias (Spain) in the year 2012 were examined. Multivariate logistic regression analyses were performed to estimate the relationships between school dropout and individual, family and school variables. Results: As for the individual characteristics, results showed that school dropouts were more irresponsible than non-dropouts. Also they had higher rates of illegal drug use and alcohol abuse. Moreover, lack of parental monitoring emerged as a key predictive factor of school dropout, beyond the type of family structure in terms of the presence of both or only one educational figure. Finally, school factors did not show a significant relationship to school dropout. Conclusions: These findings indicate that school dropout is a multidimensional process. School and family policies that emphasize the role of parental monitoring and prevent alcohol and substance abuse are recommended. PMID:28082934

  12. Risk Factors for School Dropout in a Sample of Juvenile Offenders.

    Science.gov (United States)

    Fernández-Suárez, Asunción; Herrero, Juan; Pérez, Beatriz; Juarros-Basterretxea, Joel; Rodríguez-Díaz, Francisco J

    2016-01-01

    Backgrounds: The high rates of school dropout worldwide and their relevance highlight the need for a close study of its causes and consequences. Literature has suggested that school dropout might be explained by multiple causes at different levels (individual, family, school, and neighborhood). The aim of the current study is to examine the relation between individual (defiant attitude, irresponsibility, alcohol abuse, and illegal drugs use), family (educational figure absent and parental monitoring), school factors (truancy and school conflict) and school dropout. Method: Judicial files of all juvenile offenders (218 males and 46 females) with a judicial penal measure in Asturias (Spain) in the year 2012 were examined. Multivariate logistic regression analyses were performed to estimate the relationships between school dropout and individual, family and school variables. Results: As for the individual characteristics, results showed that school dropouts were more irresponsible than non-dropouts. Also they had higher rates of illegal drug use and alcohol abuse. Moreover, lack of parental monitoring emerged as a key predictive factor of school dropout, beyond the type of family structure in terms of the presence of both or only one educational figure. Finally, school factors did not show a significant relationship to school dropout. Conclusions : These findings indicate that school dropout is a multidimensional process. School and family policies that emphasize the role of parental monitoring and prevent alcohol and substance abuse are recommended.

  13. Early dropout predictive factors in obesity treatment.

    Science.gov (United States)

    Michelini, Ilaria; Falchi, Anna Giulia; Muggia, Chiara; Grecchi, Ilaria; Montagna, Elisabetta; De Silvestri, Annalisa; Tinelli, Carmine

    2014-02-01

    Diet attrition and failure of long term treatment are very frequent in obese patients. This study aimed to identify pre-treatment variables determining dropout and to customise the characteristics of those most likely to abandon the program before treatment, thus making it possible to modify the therapy to increase compliance. A total of 146 outpatients were consecutively enrolled; 73 patients followed a prescriptive diet while 73 followed a novel brief group Cognitive Behavioural Treatment (CBT) in addition to prescriptive diet. The two interventions lasted for six months. Anthropometric, demographic, psychological parameters and feeding behaviour were assessed, the last two with the Italian instrument VCAO Ansisa; than, a semi-structured interview was performed on motivation to lose weight. To identify the baseline dropout risk factors among these parameters, univariate and multivariate logistic models were used. Comparison of the results in the two different treatments showed a higher attrition rate in CBT group, despite no statistically significant difference between the two treatment arms (P = 0.127). Dropout patients did not differ significantly from those who did not dropout with regards to sex, age, Body Mass Index (BMI), history of cycling, education, work and marriage. Regardless of weight loss, the most important factor that determines the dropout appears to be a high level of stress revealed by General Health Questionnaire-28 items (GHQ-28) score within VCAO test. The identification of hindering factors during the assessment is fundamental to reduce the dropout risk. For subjects at risk, it would be useful to dedicate a stress management program before beginning a dietary restriction.

  14. Can a Public Scholarship Program Successfully Reduce School Drop-Outs in a Time of Economic Crisis? Evidence from Indonesia

    Science.gov (United States)

    Cameron, Lisa

    2009-01-01

    This paper evaluates the role played by Indonesia's Social Safety Net Scholarships Program in reducing school drop-out rates during the Asian financial crisis. The expectation was that many families would find it difficult to keep their children in school and drop-out rates would be high. The scholarships are found to have been effective in…

  15. The Relationships between a Freshman Transition Academy, Student WESTEST Scores, and Student Dropout Rates

    Science.gov (United States)

    Jones, Roy G.

    2013-01-01

    High school administrators in the United States find students dropping out of school problematic. The federal government created the No Child Left Behind (NCLB) mandate to provide a system of accountability to public schools and school systems, while stressing the importance of teaching research-based lessons. According to the mandate, schools and…

  16. Factors associated with dropout in a group weight-loss programme: a longitudinal investigation.

    Science.gov (United States)

    Yackobovitch-Gavan, M; Steinberg, D M; Endevelt, R; Benyamini, Y

    2015-02-01

    Attrition is a major limitation of most weight management intervention programmes. The present study aimed to conduct an extensive investigation of personal, sociodemographic and treatment-related factors associated with attrition at different stages of a 10-week group weight-loss programme. The present study is part of a longitudinal, clinical intervention study comparing three conditions in a 10-week group programme: Control, Behavioural Intentions and Implementation Intentions. The study included 587 participants with a mean (SD) age of 46 (11) years (range 18-78 years) and a mean (SD) body mass index (BMI) of 31.9 (5.5) kg m(-2), with 90% being female. To characterise dropout in each week separately, as well as overall dropout (dropout until week 9, the median time of dropout), we tested several logistic regression models, including multiple imputations to cope with missing data. The results of the different dropout models consistently showed that a smaller reduction in BMI in the first 2 weeks of the programme was the strongest predictor of dropout. Dropout in the tenth and last week differed from the earlier weeks both in the relatively high dropout rate (56% of total dropout) and in that, in contrast to earlier weeks, the week 10 model included the reduction in BMI during the last 2 weeks before dropout but did not include the reduction in BMI at the initiation of the intervention. Weight-loss in the beginning of the programme is a crucial independent determinant of dropout in each week except the last one. This finding is important because it suggests a simple assessment for a major dropout risk factor in adult weight-loss intervention programmes. © 2014 The British Dietetic Association Ltd.

  17. School quality, economic status and school dropout rates among Mexican teenagers

    Directory of Open Access Journals (Sweden)

    Eunice Danitza Vargas Valle

    2016-01-01

    Full Text Available The aim of this article is to analyze the relationship between dropping out of school and the perceived quality of the last school that Mexican teenagers attended, and examine the interaction between this educational factor and the economic status of this population. Based on the 2010 National Youth Survey, the researchers used the life table to describe this relationship, and Cox regression models to analyze it, including individual, family-related and educational co-variables. The results show that the risk of dropping out of school is indirectly linked to school quality and, to a greater degree, to economic status; and that the gap between students dropping out based on school quality is slightly wider among adolescents of low academic status than among those of high status.

  18. Integrated, exposure-based treatment for PTSD and comorbid substance use disorders: Predictors of treatment dropout.

    Science.gov (United States)

    Szafranski, Derek D; Snead, Alexandra; Allan, Nicholas P; Gros, Daniel F; Killeen, Therese; Flanagan, Julianne; Pericot-Valverde, Irene; Back, Sudie E

    2017-10-01

    High rates of comorbid posttraumatic stress disorder (PTSD) and substance use disorders (SUD) have been noted in veteran populations. Fortunately, there are a number of evidence-based psychotherapies designed to address comorbid PTSD and SUD. However, treatments targeting PTSD and SUD simultaneously often report high dropout rates. To date, only one study has examined predictors of dropout from PTSD/SUD treatment. To address this gap in the literature, this study aimed to 1) examine when in the course of treatment dropout occurred, and 2) identify predictors of dropout from a concurrent treatment for PTSD and SUD. Participants were 51 male and female veterans diagnosed with current PTSD and SUD. All participants completed at least one session of a cognitive-behavioral treatment (COPE) designed to simultaneously address PTSD and SUD symptoms. Of the 51 participants, 22 (43.1%) dropped out of treatment prior to completing the full 12 session COPE protocol. Results indicated that the majority of dropout (55%) occurred after session 6, with the largest amount of dropout occurring between sessions 9 and 10. Results also indicated a marginally significant relationship between greater baseline PTSD symptom severity and premature dropout. These findings highlight inconsistencies related to timing and predictors of dropout, as well as the dearth of information noted about treatment dropout within PTSD and SUD literature. Suggestions for procedural changes, such as implementing continual symptom assessments during treatment and increasing dialog between provider and patient about dropout were made with the hopes of increasing consistency of findings and eventually reducing treatment dropout. Published by Elsevier Ltd.

  19. Meta-analysis of dropout from cognitive behavioral therapy: Magnitude, timing, and moderators.

    Science.gov (United States)

    Fernandez, Ephrem; Salem, Dara; Swift, Joshua K; Ramtahal, Nirvana

    2015-12-01

    In this era of insistence on evidence-based treatments, cognitive behavioral therapy (CBT) has emerged as a highly preferred choice for a spectrum of psychological disorders. Yet, it is by no means immune to some of the vagaries of client participation. Special concerns arise when clients drop out from treatment. The aim of this study was to answer questions about the rate and timing of dropout from CBT, with specific reference to pretreatment versus during treatment phases. Also explored were several moderators of dropout. A meta-analysis was performed on dropout data from 115 primary empirical studies involving 20,995 participants receiving CBT for a range of mental health disorders. Average weighted dropout rate was 15.9% at pretreatment, and 26.2% during treatment. Dropout was significantly associated with (a) diagnosis, with depression having the highest attrition rate; (b) format of treatment delivery, with e-therapy having the highest rates; (c) treatment setting, with fewer inpatient than outpatient dropouts; and (d) number of sessions, with treatment starters showing significantly reduced dropout as number of sessions increased. Dropout was not significantly associated with client type (adults or adolescents), therapist licensure status, study design (randomized control trial [RCT] vs. non-RCT), or publication recency. Findings are interpreted with reference to other reviews. Possible clinical applications include careful choice and supplementing of treatment setting/delivery according to the diagnosis, and use of preparatory strategies. Suggestions for future research include standardization of operational definitions of dropout, specification of timing of dropout, and exploration of additional moderator variables. (c) 2015 APA, all rights reserved).

  20. No-shows, drop-outs and completers in psychotherapeutic treatment

    DEFF Research Database (Denmark)

    Fenger, Morten Munthe; Mortensen, Erik Lykke; Poulsen, Stig Bernt

    2011-01-01

    A primary challenge in mental health services is a high rate of non-attendance (i.e. no-show and drop-out) for patients referred to treatment for psychiatric disorders.......A primary challenge in mental health services is a high rate of non-attendance (i.e. no-show and drop-out) for patients referred to treatment for psychiatric disorders....

  1. Predicting dropout from intensive outpatient cognitive behavioural therapy for binge eating disorder using pre-treatment characteristics: A naturalistic study

    NARCIS (Netherlands)

    Vroling, M.S.; Wiersma, F.E.; Lammers, M.W.; Noorthoorn, E.O.

    2016-01-01

    Background: Dropout rates in binge eating disorder (BED) treatment are high (17-30%), and predictors of dropout are unknown. Method: Participants were 376 patients following an intensive outpatient cognitive behavioural therapy programme for BED, 82 of whom (21.8%) dropped out of treatment. An

  2. High population increase rates.

    Science.gov (United States)

    1991-09-01

    In addition to its economic and ethnic difficulties, the USSR faces several pressing demographic problems, including high population increase rates in several of its constituent republics. It has now become clear that although the country's rigid centralized planning succeeded in covering the basic needs of people, it did not lead to welfare growth. Since the 1970s, the Soviet economy has remained sluggish, which as led to increase in the death and birth rates. Furthermore, the ideology that held that demography could be entirely controlled by the country's political and economic system is contradicted by current Soviet reality, which shows that religion and ethnicity also play a significant role in demographic dynamics. Currently, Soviet republics fall under 2 categories--areas with high or low natural population increase rates. Republics with low rates consist of Christian populations (Armenia, Moldavia, Georgia, Byelorussia, Russia, Lithuania, Estonia, Latvia, Ukraine), while republics with high rates are Muslim (Tadzhikistan, Uzbekistan, Turkmenistan, Kirgizia, Azerbaijan Kazakhstan). The later group has natural increase rates as high as 3.3%. Although the USSR as a whole is not considered a developing country, the later group of republics fit the description of the UNFPA's priority list. Another serious demographic issue facing the USSR is its extremely high rate of abortion. This is especially true in the republics of low birth rates, where up to 60% of all pregnancies are terminated by induced abortions. Up to 1/5 of the USSR's annual health care budget is spent on clinical abortions -- money which could be better spent on the production of contraceptives. Along with the recent political and economic changes, the USSR is now eager to deal with its demographic problems.

  3. Dropout in looking time studies: The role of infants' temperament and cognitive developmental status.

    Science.gov (United States)

    Klein-Radukic, Sarah; Zmyj, Norbert

    2015-11-01

    Dropout of infants in looking time studies sometimes occurs at high rates, raising concerns that the representativeness of the final sample might be reduced in comparison to the originally obtained sample. The current study investigated which infant characteristics play a role in dropout. Infants were presented with a preferential looking task at 6 and 9 months of age. At 9 months of age, an additional habituation task and a subsequent novelty preference task were conducted. In addition, temperament was assessed via the Infant Behavior Questionnaire - Revised (IBQ-R, Gartstein & Rothbart, 2003), and cognitive developmental status was assessed via the Cognitive Scale of the Bayley Scale of Infant and Toddler Development (BSID-III, Bayley, 2006). Dropout was positively related to the IBQ-R temperament scales Distress to Limitations and Approach, and negatively related to the scales Falling Reactivity and Cuddliness. The representativeness of the final sample regarding situation-specific temperament dimensions is affected by dropout. Dropout was not related to cognitive developmental status as measured via the BSID-III, habituation speed and novelty preference. Dropout at 6 months of age was associated with dropout at 9 months of age. We concluded that in looking time studies, the representativeness of the final sample regarding performance-relevant temperament dimensions or cognitive developmental status is not affected by dropout. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Factors associated with dropout from treatment for eating disorders: a comprehensive literature review

    Directory of Open Access Journals (Sweden)

    Tomba Elena

    2009-10-01

    Full Text Available Abstract Background Dropout (DO is common in the treatment of eating disorders (EDs, but the reasons for this phenomenon remain unclear. This study is an extensive review of the literature regarding DO predictors in EDs. Methods All papers in PubMed, PsycINFO and Cochrane Library (1980-2009 were considered. Methodological issues and detailed results were analysed for each paper. After selection according to inclusion criteria, 26 studies were reviewed. Results The dropout rates ranged from 20.2% to 51% (inpatient and from 29% to 73% (outpatient. Predictors of dropout were inconsistent due to methodological flaws and limited sample sizes. There is no evidence that baseline ED clinical severity, psychiatric comorbidity or treatment issues affect dropout. The most consistent predictor is the binge-purging subtype of anorexia nervosa. Good evidence exists that two psychological traits (high maturity fear and impulsivity and two personality dimensions (low self-directedness, low cooperativeness are related to dropout. Conclusion Implications for clinical practice and areas for further research are discussed. Particularly, these results highlight the need for a shared definition of dropout in the treatment of eating disorders for both inpatient and outpatient settings. Moreover, the assessment of personality dimensions (impulse control, self-efficacy, maturity fear and others as liability factors for dropout seems an important issue for creating specific strategies to reduce the dropout phenomenon in eating disorders.

  5. Student Perspectives of the Graduation Coach's Ethic of Care on the Dropout Epidemic in a Middle Georgia Alternative High School of Choice

    Science.gov (United States)

    Burger, Kimberly R.

    2009-01-01

    The purpose of this qualitative case study was to examine the influence of the graduation coach's ethic of care on potential dropouts (at risk high school seniors) in a Georgia alternative high school. Based on Maslow's hierarchy of needs, the objective of this research was to identify if the graduation coach's ethic of care had an influence on…

  6. Patterns of Change in Collaboration Are Associated with Baseline Characteristics and Predict Outcome and Dropout Rates in Treatment of Multi-Problem Families. A Validation Study

    Directory of Open Access Journals (Sweden)

    Egon Bachler

    2017-07-01

    Full Text Available Objective: The present study validates the Multi-Problem Family (MPF-Collaboration Scale, which measures the progress of goal directed collaboration of patients in the treatment of families with MPF and its relation to drop-out rates and treatment outcome.Method: Naturalistic study of symptom and competence-related changes in children of ages 4–18 and their caregivers.Setting: Integrative, structural outreach family therapy.Measures: The data of five different groups of goal directed collaboration (deteriorating collaboration, stable low collaboration, stable medium collaboration, stable high collaboration, improving collaboration were analyzed in their relation to treatment expectation, individual therapeutic goals (ITG, family adversity index, severity of problems and global assessment of a caregiver’s functioning, child, and relational aspects.Results: From N = 810 families, 20% displayed stable high collaboration (n = 162 and 21% had a pattern of improving collaboration. The families with stable high or improving collaboration rates achieved significantly more progress throughout therapy in terms of treatment outcome expectancy (d = 0.96; r = 0.43, reaching ITG (d = 1.17; r = 0.50, family adversities (d = 0.55; r = 0.26, and severity of psychiatric symptoms (d = 0.31; r = 0.15. Furthermore, families with stable high or improving collaboration maintained longer treatments and had a bigger chance of finishing the therapy as planned. The odds of having a stable low or deteriorating collaboration throughout treatment were significantly higher for subjects who started treatment with low treatment expectation or high family-related adversities.Conclusion: The positive outcomes of homebased interventions for multi-problem families are closely related to “stable high” and an “improving” collaboration as measured with the MPF-Collaboration Scale. Patients who fall into these groups have a high treatment outcome expectancy and reduce

  7. The High Cost of Low Graduation Rates in North Carolina. School Choice Issues in the State

    Science.gov (United States)

    Gottlob, Brian J.

    2007-01-01

    North Carolina has a dropout crisis--only two thirds of North Carolina high school students graduate. One reason this crisis has not received the attention it deserves is because the state was reporting badly inflated graduation rates (supposedly as high as 97 percent) until it finally adopted a more realistic reporting method earlier this year.…

  8. High School Substance Use as a Predictor of College Attendance, Completion, and Dropout: A National Multi-cohort Longitudinal Study.

    Science.gov (United States)

    Patrick, Megan E; Schulenberg, John E; O'Malley, Patrick M

    2016-05-01

    National data from Monitoring the Future were used to examine patterns and predictors of college attendance. Samples of American 12 th -grade students from 1977-2003 were followed for seven years (modal ages 18-25; N =10,020). College attendance and graduation patterns varied considerably over historical time and based on family background. Substance use during high school predicted a greater likelihood of never attending (for cigarettes, illegal drugs), of graduating from a 2-year rather than a 4-year school (for cigarettes), and of dropping out versus graduating from a 4-year school (for cigarettes, marijuana, and other illegal drugs). High school binge drinking predicted lower college dropout, but only in models also controlling for cigarette, marijuana, and other illicit drug use. This study provides a needed overview of adolescent predictors of patterns of college attendance among American young adults over the past three decades.

  9. The Effect of Significant International Sports Events on Qualified Detoxification Treatment Outcome - Do Drop-Out Rates Change during UEFA European Championship?

    Directory of Open Access Journals (Sweden)

    Yvonne Sofin

    Full Text Available No previous studies have evaluated the influence of significant international sports events on qualified detoxification treatment outcome. This prospective study examines the impact of the 2012 UEFA European Football Championship on inpatient treatment outcome of alcohol dependent patients. Hospital admission and premature drop-out rates of consecutively admitted alcohol dependent patients were determined before, during and immediately after the UEFA Championship in the year 2012. The admission rate of male patients increased significantly after the European Football Championship had ended whereas for female patients, no change in admission rate was found. Daily average discharge rate was calculated. No statistically relevant differences between the treatment days before, during and after the UEFA Championship was found for the discharges. During the tournament, exclusively male patients dropped out. Our results are consistent with an interpretation of an association between European Football Championship and detoxification treatment outcome. Further research to replicate and extend our findings is necessary.

  10. NEW HIGH- z FERMI BL LACS WITH THE PHOTOMETRIC DROPOUT TECHNIQUE

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, A.; Ajello, M.; Hartmann, D. H.; Paliya, V. S. [Department of Physics and Astronomy, Clemson University, SC 29634-0978 (United States); Rau, A.; Greiner, J.; Bolmer, J.; Schady, P. [Max-Planck-Institut für extraterrestrische Physik, Giessenbachstraße 1, D-85748 Garching (Germany); Domínguez, A., E-mail: akaur@g.clemson.edu [Grupo de Altas Energías, Universidad Complutense, E-28040 Madrid (Spain)

    2017-01-01

    Determining redshifts for BL Lacertae (BL Lac) objects using the traditional spectroscopic method is challenging due to the absence of strong emission lines in their optical spectra. We employ the photometric dropout technique to determine redshifts for this class of blazars using the combined 13 broadband filters from Swift -UVOT and the multi-channel imager GROND at the MPG 2.2 m telescope at ESO's La Silla Observatory. The wavelength range covered by these 13 filters extends from far-ultraviolet to the near-infrared. We report results on 40 new Fermi- detected BL Lacs with the photometric redshift determinations for five sources, with 3FGL J1918.2–4110 being the most distant in our sample at z  = 2.16. Reliable upper limits are provided for 20 sources in this sample. Using the highest energy photons for these Fermi -LAT sources, we evaluate the consistency with the gamma-ray horizon due to the extragalactic background light.

  11. University Drop-Out: An Italian Experience

    Science.gov (United States)

    Belloc, Filippo; Maruotti, Antonello; Petrella, Lea

    2010-01-01

    University students' drop-out is a crucial issue for the universities' efficiency evaluation and funding. In this paper, we analyze the drop-out rate of the Economics and Business faculty of Sapienza University of Rome. We use administrative data on 9,725 undergraduates students enrolled in three-years bachelor programs from 2001 to 2007 and…

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

    Science.gov (United States)

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

    2016-04-28

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

  13. Re-Engaging School Dropouts with Emotional and Behavioral Disorders

    Science.gov (United States)

    Wilkins, Julia; Bost, Loujeania Williams

    2015-01-01

    Students with emotional and behavioral disorders have the highest dropout rates of any student group--about 40%. The outcomes for students who drop out of school are dire but are particularly bleak for students with poor academic, interpersonal, and decision-making skills. Helping students earn a high school diploma and gain the skills needed to…

  14. The 9th Grade Shock and the High School Dropout Crisis

    Science.gov (United States)

    Pharris-Ciurej, Nikolas; Hirschman, Charles; Willhoft, Joseph

    2011-01-01

    Retrospective questions on educational attainment in national surveys and censuses tend to over-estimate high school graduation rates by 15 to 20 percentage points relative to administrative records. Administrative data on educational enrollment are, however, only available at the aggregate level (state, school district, and school levels) and the recording of inter-school transfers are generally incomplete. With access to linked individual-level administrative records from a very large “West Coast metropolitan school district” we track patterns of high school attrition and on-time high school graduation of individual students. Even with adjustments for the omission of out-of-district transfers (estimates of omission are presented), the results of this study show that failure in high school, as indexed by retention and attrition, are almost as common as on-time high school graduation. In addition to the usual risk factors of disadvantaged background, we find that the “9th grade shock”—an unpredicted decline in academic performance upon entering high school—is a key mechanism behind the continuing crisis of high school attrition. PMID:23017804

  15. Dropout Phenomena at Universities

    DEFF Research Database (Denmark)

    Larsen, Michael Søgaard; Kornbeck, Kasper Pihl; Kristensen, Rune

    Dropout from university studies comprises a number of complex phenomena with serious complex consequences and profound political attention. Further analysis of the field is, therefore, warranted. Such an analysis is offered here as a systematic review which gives answers based on the best possible...... such dropout phenomena occur at universities? What can be done by the universities to prevent or reduce such dropout phenomena?...

  16. Dropout during a driving simulator study: A survival analysis.

    Science.gov (United States)

    Matas, Nicole A; Nettelbeck, Ted; Burns, Nicholas R

    2015-12-01

    Simulator sickness is the occurrence of motion-sickness like symptoms that can occur during use of simulators and virtual reality technologies. This study investigated individual factors that contributed to simulator sickness and dropout while using a desktop driving simulator. Eighty-eight older adult drivers (mean age 72.82±5.42years) attempted a practice drive and two test drives. Participants also completed a battery of cognitive and visual assessments, provided information on their health and driving habits, and reported their experience of simulator sickness symptoms throughout the study. Fifty-two participants dropped out before completing the driving tasks. A time-dependent Cox Proportional Hazards model showed that female gender (HR=2.02), prior motion sickness history (HR=2.22), and Mini-SSQ score (HR=1.55) were associated with dropout. There were no differences between dropouts and completers on any of the cognitive abilities tests. Older adults are a high-risk group for simulator sickness. Within this group, female gender and prior motion sickness history are related to simulator dropout. Higher reported experience of symptoms of simulator sickness increased rates of dropout. The results highlight the importance of screening and monitoring of participants in driving simulation studies. Older adults, females, and those with a prior history of motion sickness may be especially at risk. Copyright © 2015 Elsevier Ltd and National Safety Council. All rights reserved.

  17. Individual, social, and family factors associated with high school dropout among low-SES youth: Differential effects as a function of immigrant status.

    Science.gov (United States)

    Archambault, Isabelle; Janosz, Michel; Dupéré, Véronique; Brault, Marie-Christine; Andrew, Marie Mc

    2017-09-01

    In most Western countries, the individual, social, and family characteristics associated with students' dropout in the general population are well documented. Yet, there is a lack of large-scale studies to establish whether these characteristics have the same influence for students with an immigrant background. The first aim of this study was to assess the differences between first-, second-, and third-generation-plus students in terms of the individual, social, and family factors associated with school dropout. Next, we examined the differential associations between these individual, social, and family factors and high school dropout as a function of students' immigration status. Participants were 2291 students (54.7% with an immigrant background) from ten low-SES schools in Montreal (Quebec, Canada). Individual, social, and family predictors were self-reported by students in secondary one (mean age = 12.34 years), while school dropout status was obtained five or 6 years after students were expected to graduate. Results of logistic regressions with multiple group latent class models showed that first- and second-generation students faced more economic adversity than third-generation-plus students and that they differed from each other and with their native peers in terms of individual, social, and family risk factors. Moreover, 40% of the risk factors considered in this study were differentially associated with first-, second-, and third-generation-plus students' failure to graduate from high school. These results provide insights on immigrant and non-immigrant inner cities' students experiences related to school dropout. The implications of these findings are discussed. © 2017 The British Psychological Society.

  18. Prediction of Student Dropout in E-Learning Program Through the Use of Machine Learning Method

    Directory of Open Access Journals (Sweden)

    Mingjie Tan

    2015-02-01

    Full Text Available The high rate of dropout is a serious problem in E-learning program. Thus it has received extensive concern from the education administrators and researchers. Predicting the potential dropout students is a workable solution to prevent dropout. Based on the analysis of related literature, this study selected student’s personal characteristic and academic performance as input attributions. Prediction models were developed using Artificial Neural Network (ANN, Decision Tree (DT and Bayesian Networks (BNs. A large sample of 62375 students was utilized in the procedures of model training and testing. The results of each model were presented in confusion matrix, and analyzed by calculating the rates of accuracy, precision, recall, and F-measure. The results suggested all of the three machine learning methods were effective in student dropout prediction, and DT presented a better performance. Finally, some suggestions were made for considerable future research.

  19. The Effects Multiple Intervention and Prevention Programs Have on the Graduation and Dropout Rates of Two Major Urban School Districts in Texas

    Science.gov (United States)

    Briones, Ernestina M.; Jones, Don; Challoo, Linda

    2015-01-01

    In the United States, seven thousand students drop out of school every day (Alliance for Excellence Education, 2010); that is more than one million per year (Balfanz & Bridgeland, 2014). Administrators, former educators and private entities have taken an interest in the dropout epidemic and have developed numerous dropout prevention and…

  20. Baseline Motivation Type as a Predictor of Dropout in a Healthy Eating Text Messaging Program.

    Science.gov (United States)

    Coa, Kisha; Patrick, Heather

    2016-09-29

    Growing evidence suggests that text messaging programs are effective in facilitating health behavior change. However, high dropout rates limit the potential effectiveness of these programs. This paper describes patterns of early dropout in the HealthyYou text (HYTxt) program, with a focus on the impact of baseline motivation quality on dropout, as characterized by Self-Determination Theory (SDT). This analysis included 193 users of HYTxt, a diet and physical activity text messaging intervention developed by the US National Cancer Institute. Descriptive statistics were computed, and logistic regression models were run to examine the association between baseline motivation type and early program dropout. Overall, 43.0% (83/193) of users dropped out of the program; of these, 65.1% (54/83; 28.0% of all users) did so within the first 2 weeks. Users with higher autonomous motivation had significantly lower odds of dropping out within the first 2 weeks. A one unit increase in autonomous motivation was associated with lower odds (odds ratio 0.44, 95% CI 0.24-0.81) of early dropout, which persisted after adjusting for level of controlled motivation. Applying SDT-based strategies to enhance autonomous motivation might reduce early dropout rates, which can improve program exposure and effectiveness.

  1. A Consensual Qualitative Research Study of the Transformation from High School Dropout to Second Chance Alumni

    Science.gov (United States)

    Smith, Jayne E.

    2013-01-01

    This study focused on understanding the perceived process of change, outcomes and influencing factors experienced by high school graduates of Urban Corps of San Diego County (UCO) from a bioecological theory of human development standpoint. UCO is a second chance high school diploma-job training program that offers students free mental health…

  2. High School Dropout in Proximal Context: The Triggering Role of Stressful Life Events

    Science.gov (United States)

    Dupéré, Véronique; Dion, Eric; Leventhal, Tama; Archambault, Isabelle; Crosnoe, Robert; Janosz, Michel

    2018-01-01

    Adolescents who drop out of high school experience enduring negative consequences across many domains. Yet, the circumstances triggering their departure are poorly understood. This study examined the precipitating role of recent psychosocial stressors by comparing three groups of Canadian high school students (52% boys; M[subscript…

  3. Potential risk factors associated with risk for drop-out and relapse during and following withdrawal of opioid prescription medication.

    Science.gov (United States)

    Heiwe, Susanne; Lönnquist, Ingeborg; Källmén, Håkan

    2011-10-01

    Withdrawal of opioid medication in patients with chronic pain has a drop-out and relapse problem. To evaluate if depressive symptoms, anxiety and pain intensity are potential risk factors for drop-out or relapse during the withdrawal process. Further, to assess internal consistency of scales for assessment of these potential risk factors. Twenty-nine patients were included. After 2 years 28 of these were followed-up. Those with depressive symptoms at baseline had a significant risk for drop-out from the withdrawal program (odds ratio 1.37) and relapse into use of opioids at follow-up (odds ratio 1.44). Drop-outs rated depressive symptoms significantly higher before detoxification. Those who relapsed rated significantly higher for pain intensity, depressive symptoms and abstinence prior to withdrawal. All scales had high reliability. To avoid drop-out and relapse clinical practice need to screen for depressive symptoms, pain intensity, and abstinence. This article presents significant reliability of scales useful within dependency centers. They can be used to identify these risk factors for drop-out and relapse, respectively, when initiating the withdrawal process. Taking these risk factors into consideration could improve the outcome of the withdrawal process by preventing drop-out and relapse. Copyright © 2011 European Federation of International Association for the Study of Pain Chapters. Published by Elsevier Ltd. All rights reserved.

  4. School Motivation and High School Dropout: The Mediating Role of Educational Expectation

    Science.gov (United States)

    Fan, Weihua; Wolters, Christopher A.

    2014-01-01

    Background: A good deal of evidence indicates that students' motivational beliefs and attitudes play a critical role in their academic success. Research studies on how motivational factors may help determine whether students remain in high school or drop out, however, are relatively few. More specifically, there is a lack of research…

  5. Identifying Characteristics of High School Dropouts: Data Mining with A Decision Tree Model

    Science.gov (United States)

    Veitch, William Robert.

    2004-01-01

    The notion that all students should finish high school has grown throughout the last century and continues to be an important goal for all educational levels in this new century. Non-completion has been related to all sorts of social, financial, and psychological issues. Many studies have attempted to put together a process that will identify…

  6. Ability, Parental Valuation of Education and the High School Dropout Decision

    DEFF Research Database (Denmark)

    Foley, Kelly; Gallipoli, Giovanni; Green, David

    of the factor model set out in Carneiro, Hansen, and Heckman (2003). Specically, we consider the impact of cognitive and non-cognitive ability and the value that parents place on education. Our results support three main conclusions. First, cognitive ability at age 15 has a substantial impact on dropping out....... Second, parental valuation of education has an impact of approximately the same size as cognitive ability e ects for medium and low ability teenagers. A low ability teenager has a probability of dropping out of approximately .03 if his parents place a high value on education but .36 if their education......We use a large, rich Canadian micro-level dataset to examine the channels through which family socio-economic status and unobservable characteristics a ect children's decisions to drop out of high school. First, we document the strength of observable socio-economic factors: our data suggest...

  7. IRD dropout study

    Science.gov (United States)

    Yalowitz, Jeffrey S.; Schroer, Michael A.; Dickson, John E., Jr.

    1992-01-01

    This final report describes work performed by SRS Technologies for the NASA Marshall Space Flight Center under Contract NAS8-39077, entitled 'Integrated Receiver-Decoder Dropout Study'. The purpose of the study was to determine causes of signal fading effects on ultra-high-frequency (UHF) range safety transmissions to the Space Shuttle during flyout. Of particular interest were deep fades observed at the External Tank (ET) Integrated Receiver-Decoder (IRD) during the flyout interval between solid rocket booster separation and ET separation. Analytical and simulation methods were employed in this study to assess observations captured in flight telemetry data records. Conclusions based on the study are presented in this report, and recommendations are given for future experimental validation of the results.

  8. Rethinking Dropout in Online Higher Education: The Case of the Universitat Oberta de Catalunya

    Directory of Open Access Journals (Sweden)

    Josep Grau-Valldosera

    2014-02-01

    Full Text Available In recent years, several studies have been carried out into the reasons why students drop out of online higher education, following the rise in the relative weight of this form of education. However, more effort has gone into analyzing the causes of this phenomenon than into trying to characterize students who drop out, that is defining what a dropout student is. But obtaining a proper definition of dropout is just as important as describing its causes. It also appears that the definition of dropout is very sensitive to context. As one of the main findings of this article, we reach a pure empirical definition, at a programme level, of students who drop out of an online higher education context with non-mandatory enrollment. This definition is based on the probability of students not continuing a specific academic programme following several consecutive semesters of “theoretical break”, and is highly adaptable to institutions offering distance education with no permanence requirements, that is ones offering the possibility of taking breaks. Our findings show that there are differences regarding the number of consecutive semesters that define dropout depending on whether the programme requires previous experience or not. Additionally, we observe significant differences in the dropout rate between specific programmes, as well as a higher level of dropout in the first semesters. Analyzing the reasons behind these facts should help higher education institutions to make more sound and efficient decisions.

  9. Student Drop-Out Trends at Sultan Qaboos University and Kuwait University: 2000-2011

    Science.gov (United States)

    Al Ghanboosi, Salim Saleem; Alqahtani, Abdulmuhsen Ayedh

    2013-01-01

    The current study aims to explore the drop-out trends at Sultan Qaboos. University and Kuwait University. Archival data of the period 2000-2011 were used to achieve this goal. Main findings showed that (a) male drop-out rates are higher than female drop-out rates; (b) drop- out rates at scientific colleges are higher; (c) drop-out rates of…

  10. Factors associated with pretreatment and treatment dropouts: comparisons between Aboriginal and non-Aboriginal clients admitted to medical withdrawal management

    Science.gov (United States)

    2013-01-01

    Background Addiction treatment faces high pretreatment and treatment dropout rates, especially among Aboriginals. In this study we examined characteristic differences between Aboriginal and non-Aboriginal clients accessing an inpatient medical withdrawal management program, and identified risk factors associated with the probabilities of pretreatment and treatment dropouts, respectively. Methods 2231 unique clients (Aboriginal = 451; 20%) referred to Vancouver Detox over a two-year period were assessed. For both Aboriginal and non-Aboriginal groups, multivariate logistic regression analyses were conducted with pretreatment dropout and treatment dropout as dependent variables, respectively. Results Aboriginal clients had higher pretreatment and treatment dropout rates compared to non-Aboriginal clients (41.0% vs. 32.7% and 25.9% vs. 20.0%, respectively). For Aboriginal people, no fixed address (NFA) was the only predictor of pretreatment dropout. For treatment dropout, significant predictors were: being female, having HCV infection, and being discharged on welfare check issue days or weekends. For non-Aboriginal clients, being male, NFA, alcohol as a preferred substance, and being on methadone maintenance treatment (MMT) at referral were associated with pretreatment dropout. Significant risk factors for treatment dropout were: being younger, having a preferred substance other than alcohol, having opiates as a preferred substance, and being discharged on weekends. Conclusions Our results highlight the importance of social factors for the Aboriginal population compared to substance-specific factors for the non-Aboriginal population. These findings should help clinicians and decision-makers to recognize the importance of social supports especially housing and initiate appropriate services to improve treatment intake and subsequent retention, physical and mental health outcomes and the cost-effectiveness of treatment. PMID:24325629

  11. School Location, School Section and Students' Gender as Predictors to Secondary School Dropout Rate in Rivers State, Nigeria

    Science.gov (United States)

    Christian, Mathew

    2015-01-01

    This study was undertaken to underscore the extent the variables of school location, students' gender and school section can predict the rate of drop out of secondary school students. Ex post facto design was adopted and all data on students' enrollment, retention and completion were collected from available schools' records for two cohorts of…

  12. Predictors of school dropout among adolescents in Puerto Rico.

    Science.gov (United States)

    Calderón, José M; Robles, Rafaela R; Reyes, Juan C; Matos, Tomás D; Negrón, Juan L; Cruz, Miguel A

    2009-12-01

    This research aims to understand the circumstances associated with school dropout in a cohort of Puerto Rican adolescents. The study collected data from adolescents and their parents. Information related to school dropout among adolescents was obtained from the second year follow-up data from the longitudinal study funded by NIDA "Risky Families Embedded in Risky Environments" (Grant No. R01 DA 15301). Data was collected employing a self-administered and a face-to-face interview protocol. Prediction of school dropout was assessed throughout adolescent characteristics, family background, school experiences and behaviors. During the second follow-up, two years after the baseline assessment, approximately 6.2% of the adolescents reported dropping out from school. Logistic regression analysis indicates that older adolescents (OR = 6.6, 1.37-31.67), whose mother used drugs during pregnancy (OR = 4.9, 1.31-17.91), who reported high rates of absenteeism (OR = 4.8, 1.63-14.13), high school grade retention (OR = 3.7, 1.14-12.05), and attended school where teachers were attacked or wounded by students (O R =7.0, 1.44-34.17) were more likely to dropout of school. : These findings emphasize the need to further understand the effects of different elements of adolescents' environment such as family and school. It has been posited that dropping out of school is a process whose characteristics can be detected long before it occurs. The fact that students who dropout are more likely to report skip classes and grade retention can be relevant elements in prevention and early intervention for teachers and other school personnel.

  13. Higher Education Drop-out in Spain--Particular Case of Universities in Galicia

    Science.gov (United States)

    Arce, Maria Elena; Crespo, Barbara; Míguez-Álvarez, Carla

    2015-01-01

    The existence of a high university dropout rate in Spain is undeniable. Data shows that approximately one out of five students drop out from college. During the economic expansion period (2001-2007) more students abandoned their studies than during the crisis period (2007-2011). This situation also affects unemployment rates due to the fact that…

  14. Understanding Catalan University Dropout from a Comparative Approach

    OpenAIRE

    Rodríguez-Gómez, David; Feixas, Mònica; Gairín, Joaquín; Muñoz, José Luís

    2012-01-01

    Last decade yielded important research to understand the extent to which university dropout is having relevant consequences for higher education. The dropout rate has also been quantified and used as an indicator of performance (Dearing, 1996; Bricall, 2000; Rauret & Grifol, 2001; OECD, 2008; Mandelson, 2009). The aim of this paper is to offer an extensive perspective on how university dropout is being studied and faced in several contexts (America, Europe and, more concretely, Spain and Cata...

  15. The Effect of Graduation Coaches and Credit Recovery Programs on the Dropout Rate of At-Risk Grade 9 Students

    Science.gov (United States)

    Bowling, Jan

    2013-01-01

    The objective of this study was to identify the characteristics of effective graduation coaches (GCs) and credit recovery programs and explain the influence of a GC and a credit recovery program on Grade 9 students at risk of dropping out. The purpose of this study was to determine whether a high school GC and enrollment in a credit recovery…

  16. Physical exercise in treatment of AUDs – a dropout study

    DEFF Research Database (Denmark)

    Sari, Sengül; Roessler, Kirsten Kaya

    Background: The Healthy Lifestyle Study is one out of five alcohol research studies in the RESCueH research project. It is a randomized controlled study which aims to understand the effect of physical exercise on alcohol, fitness and wellness outcomes for outpatients in treatment of alcohol use...... disorders. Relapse rates in treatment of AUD ranges between 60 and 90 % in the first year after treatment. The Healthy Lifestyle Study offers physical exercise as add on treatment to better maintenance. However intervention studies with physical exercise can suffer from high dropout rates. To gain a better...... understanding of lived lives of dropouts from The Healthy Lifestyle Study, a qualitative interview study was conducted. Objective: This interview study aims to gain better understanding of and more in depth knowledge about how alcohol patients experience, think and feel about physical exercise when...

  17. School Dropouts in Perspective.

    Science.gov (United States)

    Sherraden, Michael W.

    1986-01-01

    Discusses aspects of the school dropout problem: figures and trends, related youth problems (unemployment, crime and vandalism, drug and alcohol abuse, political alienation, teen pregnancy and childbirth, homicide and suicide), and suggestions for solving the problem. (CT)

  18. Building a Grad Nation: Progress and Challenge in Ending the High School Dropout Epidemic. Executive Summary. Annual Update, 2012

    Science.gov (United States)

    Balfanz, Robert; Bridgeland, John M.; Bruce, Mary; Fox, Joanna Hornig

    2012-01-01

    This 2012 report shows that high school graduation rates continue to improve nationally and across many states and school districts, with 12 states accounting for the majority of new graduates over the last decade. Tennessee and New York continue to lead the nation with double-digit gains in high school graduation rates over the same period. The…

  19. Building a Grad Nation: Progress and Challenge in Ending the High School Dropout Epidemic. Annual Update, 2012

    Science.gov (United States)

    Balfanz, Robert; Bridgeland, John M.; Bruce, Mary; Fox, Joanna Hornig

    2012-01-01

    In 2010, the authors shared a Civic Marshall Plan to create a Grad Nation. Through that first report and subsequent update, they saw hopeful signs of progress in boosting high school graduation rates in communities across the country. This 2012 report shows that high school graduation rates continue to improve nationally and across many states and…

  20. Reducing Dropouts in Online Education-Group Tutoring in Virtual Seminars and Support Structures

    Science.gov (United States)

    Holmgren, Robert; Johansson, Sigurd

    2012-01-01

    This paper describes a development project aimed at reducing the large number of dropouts in online degree project courses. The idea was that the introduction of group tutorials in virtual seminars, combined with extensive support materials, would reduce dropout rates. Among the students who participated, the dropout rate was reduced by 50%…

  1. High Rate Digital Demodulator ASIC

    Science.gov (United States)

    Ghuman, Parminder; Sheikh, Salman; Koubek, Steve; Hoy, Scott; Gray, Andrew

    1998-01-01

    The architecture of High Rate (600 Mega-bits per second) Digital Demodulator (HRDD) ASIC capable of demodulating BPSK and QPSK modulated data is presented in this paper. The advantages of all-digital processing include increased flexibility and reliability with reduced reproduction costs. Conventional serial digital processing would require high processing rates necessitating a hardware implementation in other than CMOS technology such as Gallium Arsenide (GaAs) which has high cost and power requirements. It is more desirable to use CMOS technology with its lower power requirements and higher gate density. However, digital demodulation of high data rates in CMOS requires parallel algorithms to process the sampled data at a rate lower than the data rate. The parallel processing algorithms described here were developed jointly by NASA's Goddard Space Flight Center (GSFC) and the Jet Propulsion Laboratory (JPL). The resulting all-digital receiver has the capability to demodulate BPSK, QPSK, OQPSK, and DQPSK at data rates in excess of 300 Mega-bits per second (Mbps) per channel. This paper will provide an overview of the parallel architecture and features of the HRDR ASIC. In addition, this paper will provide an over-view of the implementation of the hardware architectures used to create flexibility over conventional high rate analog or hybrid receivers. This flexibility includes a wide range of data rates, modulation schemes, and operating environments. In conclusion it will be shown how this high rate digital demodulator can be used with an off-the-shelf A/D and a flexible analog front end, both of which are numerically computer controlled, to produce a very flexible, low cost high rate digital receiver.

  2. Selected determinants may account for dropout risks among medical students

    DEFF Research Database (Denmark)

    Mørcke, Anne Mette; O'Neill, Lotte; Kjeldsen, Inge Trads

    2012-01-01

    INTRODUCTION: The dropout level from the Danish medical schools is high, but we have only little insight into this problem. The purpose of this study was to qualify the ongoing discussions concerning dropout. MATERIAL AND METHODS: In this retrospective cohort study, relevant variables were...... extracted from the established database of Aarhus University for the 639 students initiating medicine studies between 1 January 1999 and 31December 2000. A multivariate pre-admission and post-admission model was examined. RESULTS: Of the 639 medical students, 20% dropped out. Most students dropped out...... during their first year. The type of admission exam was a strong predictor of dropout in the pre-admission model, whereas previous higher education protected against dropout. Obtaining leave was a very strong predictor of dropout in the post-admission model, whereas high grades protected against dropout...

  3. Predicting Psychotherapy Dropouts: A Multilevel Approach.

    Science.gov (United States)

    Kegel, Alexander F; Flückiger, Christoph

    2015-01-01

    The role of therapeutic processes in predicting premature termination of psychotherapy has been a particular focus of recent research. The purpose of this study was to contrast outpatients who completed therapy and those who dropped out with respect to their self-reported in-session experiences of self-esteem, mastery, clarification and the therapeutic alliance. The 296 patients with mixed disorders were treated with an integrative form of cognitive-behavioural therapy without pre-determined time limit (M = 20.2 sessions). Multilevel analyses indicated that patients who did not completetreatment reported, on average, lower levels of self-esteem, mastery and clarification and lower ratings of their therapeutic alliance in treatment in contrast to patients who completed therapy. Patient-reported change in self-esteem experiences over the course of treatment turned out to be the strongest predictor of dropout from psychotherapy or successful completion. When dropout occurred before the average treatment length was reached, patients reported fewer clarifying experiences as early as the first session and their ratings of the therapeutic alliance were characterized by an absence of positive development. Both of these aspects seem to be involved in patients' decisions to leave treatment early. The findings underscore the importance of the therapeutic process in understanding the mechanisms behind treatment dropout. Analyses data from 296 patients at a private outpatient clinic in a routine practice setting (CBT). Completer/dropout definition: presence or absence of measurement battery at post-assessment. Focuses on change in therapy processes by investigating post-session reports. Finds that positive changes in self-esteem experiences is the most robust predictor of dropout, followed by ratings of clarification experiences and the global alliance. In line with recent dropout research, these process indicators might help to detect therapeutic situations that are

  4. Longitudinal associations between different dementia diagnoses and medication use jointly accounting for dropout.

    Science.gov (United States)

    Agogo, George O; Ramsey, Christine M; Gnjidic, Danijela; Moga, Daniela C; Allore, Heather

    2018-04-18

    ABSTRACTBackground:Longitudinal studies of older adults are characterized by high dropout rates, multimorbid conditions, and multiple medication use, especially proximal to death. We studied the association between multiple medication use and incident dementia diagnoses including Alzheimer's disease (AD), vascular dementia (VD), and Lewy-body dementia (LBD), simultaneously accounting for dropout. Using the National Alzheimer's Coordinating Center data with three years of follow-up, a set of covariate-adjusted models that ignore dropout was fit to complete-case data, and to the whole-cohort data. Additionally, covariate-adjusted joint models with shared random effects accounting for dropout were fit to the whole-cohort data. Multiple medication use was defined as polypharmacy (⩾ five medications), hyperpolypharmacy (⩾ ten medications), and total number of medications. Incident diagnoses were 2,032 for AD, 135 for VD, and 139 for LBD. Percentages of dropout at the end of follow-up were as follows: 71.8% for AD, 81.5% for VD, and 77.7% for LBD. The odds ratio (OR) estimate for hyperpolypharmacy among those with LBD versus AD was 2.19 (0.78, 6.15) when estimated using complete-case data and 3.00 (1.66, 5.40) using whole-cohort data. The OR reduced to 1.41 (0.76, 2.64) when estimated from the joint model accounting for dropout. The OR for polypharmacy using complete-case data differed from the estimates using whole-cohort data. The OR for dementia diagnoses on total number of medications was similar, but non-significant when estimated using complete-case data. Reasons for dropout should be investigated and appropriate statistical methods should be applied to reduce bias in longitudinal studies among high-risk dementia cohorts.

  5. Predicting dropout using student- and school-level factors: An ecological perspective.

    Science.gov (United States)

    Wood, Laura; Kiperman, Sarah; Esch, Rachel C; Leroux, Audrey J; Truscott, Stephen D

    2017-03-01

    High school dropout has been associated with negative outcomes, including increased rates of unemployment, incarceration, and mortality. Dropout rates vary significantly depending on individual and environmental factors. The purpose of our study was to use an ecological perspective to concurrently explore student- and school-level predictors associated with dropout for the purpose of better understanding how to prevent it. We used the Education Longitudinal Study of 2002 dataset. Participants included 14,106 sophomores across 684 public and private schools. We identified variables of interest based on previous research on dropout and implemented hierarchical generalized linear modeling. In the final model, significant student-level predictors included academic achievement, retention, sex, family socioeconomic status (SES), and extracurricular involvement. Significant school-level predictors included school SES and school size. Race/ethnicity, special education status, born in the United States, English as first language, school urbanicity, and school region did not significantly predict dropout after controlling for the aforementioned predictors. Implications for prevention and intervention efforts within a multitiered intervention model are discussed. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  6. Research-Based Strategies and Best Practices for Dropout Prevention

    Science.gov (United States)

    Smink, Jay

    2009-01-01

    The National Dropout Prevention Center (NDPC) at Clemson University has been at the forefront of identifying model dropout prevention programs and promoting the use of best practices to increase the graduation rates in schools since 1986. The structure for these varied interventions and solutions takes the form of effective strategies, model…

  7. Student Drop-Out from German Higher Education Institutions

    Science.gov (United States)

    Heublein, Ulrich

    2014-01-01

    28% of students of any one year currently give up their studies in bachelor degree programmes at German higher education institutions. Drop-out is to be understood as the definite termination in the higher education system without obtaining an academic degree. The drop-out rate is thereby calculated with the help of statistical estimation…

  8. Understanding Catalan University Dropout from a Cross-National Approach

    Science.gov (United States)

    Rodríguez-Gómez, David; Feixas, Mònica; Gairín, Joaquín; Muñoz, José Luís

    2015-01-01

    The dropout rate is an indicator of complex analysis and there is no consensus on its significance. Universities lack systematized, univocal methods for collecting student dropout data, making measurement problematic. In consequence, the formulas applied to analyze this phenomenon differ between countries and it is therefore an immense challenge…

  9. Dropout from cognitive-behavioral therapy for eating disorders: A meta-analysis of randomized, controlled trials.

    Science.gov (United States)

    Linardon, Jake; Hindle, Annemarie; Brennan, Leah

    2018-05-01

    Cognitive-behavioral therapy (CBT) is efficacious for a range of eating disorder presentations, yet premature dropout is one factor that might limit CBTs effectiveness. Improved understanding of dropout from CBT for eating disorders is important. This meta-analysis aimed to study dropout from CBT for eating disorders in randomized controlled trials (RCTs), by (a) identifying the types of dropout definitions applied, (b) providing estimates of dropout, (c) comparing dropout rates from CBT to non-CBT interventions for eating disorders, and (d) testing moderators of dropout. RCTs of CBT for eating disorders that reported rates of dropout were searched. Ninety-nine RCTs (131 CBT conditions) were included. Dropout definitions varied widely across studies. The overall dropout estimate was 24% (95% CI = 22-27%). Diagnostic type, type of dropout definition, baseline symptom severity, study quality, and sample age did not moderate this estimate. Dropout was highest among studies that delivered internet-based CBT and was lowest in studies that delivered transdiagnostic enhanced CBT. There was some evidence that longer treatment protocols were associated with lower dropout. No significant differences in dropout rates were observed between CBT and non-CBT interventions for all eating disorder subtypes. Present study dropout estimates are hampered by the use of disparate dropout definitions applied. This meta-analysis highlights the urgency for RCTs to utilize a standardized dropout definition and to report as much information on patient dropout as possible, so that strategies designed to minimize dropout can be developed, and factors predictive of CBT dropout can be more easily identified. © 2018 Wiley Periodicals, Inc.

  10. Family Background and University Dropouts during the Crisis: The Case of Italy

    Science.gov (United States)

    Ghignoni, Emanuela

    2017-01-01

    The Italian university system has long been characterised by high non-completion rates, though aggregate data show a slight reduction of dropouts in recent years. The most straightforward theoretical explanation for this lies in the lowering opportunity cost of studying due to the financial and economic crisis. Nonetheless, this interpretation is…

  11. Refining Success and Dropout in MOOCs Based on the Intention-Behaviour Gap

    NARCIS (Netherlands)

    Henderikx, Maartje; Kreijns, Karel; Kalz, Marco

    2016-01-01

    Currently success measurement of MOOCs is certificate- and completion-centric and fails to take student intention into account. This results in high dropout rates of 90-95%. While this view of success has been critiqued by the research community, no suitable alternative has yet been developed. This

  12. Meta-Analysis of Dropout in Treatments for Posttraumatic Stress Disorder

    Science.gov (United States)

    Imel, Zac E.; Laska, Kevin; Jakupcak, Matthew; Simpson, Tracy L.

    2013-01-01

    Objective: Many patients drop out of treatments for posttraumatic stress disorder (PTSD); some clinicians believe that trauma-focused treatments increase dropout. Method: We conducted a meta-analysis of dropout among active treatments in clinical trials for PTSD (42 studies; 17 direct comparisons). Results: The average dropout rate was 18%, but it…

  13. [Dropout behavior during inpatient psychotherapy ].

    Science.gov (United States)

    Martens, Ute; Rempel, Irene; Zipfel, Stephan; Enck, Paul; Teufel, Martin

    2014-01-01

    Dropouts result in far-reaching consequences for the individual patient, fellow patients, therapists, and the clinic. This study was aimed at early identification of patients with a dropout risk. Data from patients of the Department of Psychosomatic Medicine and Psychotherapy of the Medical University Clinic of Tübingen (Germany) were analyzed retrospectively in a case-control study (matched). Differences in the results of various questionnaires (SCL-90-R, IIP-D, SF-36) regarding reasons for dropout and sociodemographic data were analyzed. A total of 59 dropouts, 50 females and 9 males, were included. They were split into 28 early dropouts and 31 late dropouts. The data were compared between early and late dropouts and control group. Early dropouts were significantly younger than late dropouts; they tended to live with their parents or on their own, and suffered more frequently from eating disorders. Late dropouts lived together with partners and suffered from somatoform disorders more frequently than early dropouts. The reasons given for dropout did not differ between the groups. No differences between dropouts and the controls were found with respect to psychopathology (SCL- 90-R) and quality of life (SF-36). Late dropouts did show significantly lower scores on the scale "autocracy/dominance" than the controls (IIP). Therapy dropout is a multifactorial occurrence. It is generally not predictable, though it may be predicted with different instruments on the basis of a diagnosis, especially with respect to interpersonal behavior patterns. In further studies, targeted interventions should be developed and tested which enable procedures to minimize the risk of dropout and to achieve complete treatment according to patients' intentions.

  14. A Systematic Review of Consent Procedures, Participation Rates, and Main Findings of Health-Related Research in Alternative High Schools from 2010 to 2015

    Science.gov (United States)

    Johnson, Karen E.; Morris, Marian; Rew, Lynn; Simonton, Amanda J.

    2016-01-01

    There is a well-established link between educational attainment and health. Alternative high schools (AHSs) serve students who are at risk for school dropout. Health-related research conducted in AHSs has been sparse. Achieving high participation rates is critical to producing generalizable results and can be challenging in research with…

  15. Stereotype confirmation concerns predict dropout from cognitive behavioral therapy for social anxiety disorder.

    Science.gov (United States)

    Johnson, Suzanne; Price, Matthew; Mehta, Natasha; Anderson, Page L

    2014-08-19

    There are high attrition rates observed in efficacy studies for social anxiety disorder, and research has not identified consistent nor theoretically meaningful predictors of dropout. Pre-treatment symptom severity and demographic factors, such as age and gender, are sometimes predictive of dropout. The current study examines a theoretically meaningful predictor of attrition based on experiences associated with social group membership rather than differences between social group categories--fear of confirming stereotypes. This is a secondary data analysis of a randomized controlled trial comparing two cognitive behavioral treatments for social anxiety disorder: virtual reality exposure therapy and exposure group therapy. Participants (N = 74) with a primary diagnosis of social anxiety disorder who were eligible to participate in the parent study and who self-identified as either "African American" (n = 31) or "Caucasian" (n = 43) completed standardized self-report measures of stereotype confirmation concerns (SCC) and social anxiety symptoms as part of a pre-treatment assessment battery. Hierarchical logistic regression showed that greater stereotype confirmation concerns were associated with higher dropout from therapy--race, age, gender, and pre-treatment symptom severity were not. Group treatment also was associated with higher dropout. These findings urge further research on theoretically meaningful predictors of attrition and highlight the importance of addressing cultural variables, such as the experience of stereotype confirmation concerns, during treatment of social anxiety to minimize dropout from therapy.

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

    Science.gov (United States)

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

    2017-08-01

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

  17. Factors associated with non-participation and dropout among cancer patients in a cluster-randomised controlled trial.

    Science.gov (United States)

    Roick, J; Danker, H; Kersting, A; Briest, S; Dietrich, A; Dietz, A; Einenkel, J; Papsdorf, K; Lordick, F; Meixensberger, J; Mössner, J; Niederwieser, D; Prietzel, T; Schiefke, F; Stolzenburg, J-U; Wirtz, H; Singer, S

    2018-01-01

    We investigated the impact of demographic and disease related factors on non-participation and dropout in a cluster-randomised behavioural trial in cancer patients with measurements taken between hospitalisation and 6 months thereafter. The percentages of non-participation and dropout were documented at each time point. Factors considered to be potentially related with non-participation and dropout were as follows: age, sex, marital status, education, income, employment status, tumour site and stage of disease. Of 1,338 eligible patients, 24% declined participation at baseline. Non-participation was higher in older patients (Odds Ratio [OR] 2.1, CI: 0.6-0.9) and those with advanced disease (OR 2.0, CI: 0.1-1.3). Dropout by 6 months was 25%. Dropout was more frequent with increased age (OR 2.8, CI: 0.8-1.2), advanced disease (OR 3.0, CI: 1.0-1.2), being married (OR 2.4, CI 0.7-1.1) and less frequent with university education (OR 0.4, CI -1.3 to -0.8) and middle income (OR 0.4, CI -0.9 to -0.7). When planning clinical trials, it is important to be aware of patient groups at high risk of non-participation or dropout, for example older patients or those with advanced disease. Trial designs should consider their special needs to increase their rate of participation. © 2017 John Wiley & Sons Ltd.

  18. Predictive factors of dropout from inpatient treatment for anorexia nervosa.

    Science.gov (United States)

    Roux, H; Ali, A; Lambert, S; Radon, L; Huas, C; Curt, F; Berthoz, S; Godart, Nathalie

    2016-09-30

    patients are under or over 18 years of age. Besides the therapeutic adjustments required in view of the factors identified, the high dropout rate raises the issue of resorting more frequently to compulsory care measures among adults.

  19. Quantifying the Precipitation Loss of Radiation Belt Electrons during a Rapid Dropout Event

    Science.gov (United States)

    Pham, K. H.; Tu, W.; Xiang, Z.

    2017-12-01

    Relativistic electron flux in the radiation belt can drop by orders of magnitude within the timespan of hours. In this study, we used the drift-diffusion model that includes azimuthal drift and pitch angle diffusion of electrons to simulate low-altitude electron distribution observed by POES/MetOp satellites for rapid radiation belt electron dropout event occurring on May 1, 2013. The event shows fast dropout of MeV energy electrons at L>4 over a few hours, observed by the Van Allen Probes mission. By simulating the electron distributions observed by multiple POES satellites, we resolve the precipitation loss with both high spatial and temporal resolution and a range of energies. We estimate the pitch angle diffusion coefficients as a function of energy, pitch angle, and L-shell, and calculate corresponding electron lifetimes during the event. The simulation results show fast electron precipitation loss at L>4 during the electron dropout, with estimated electron lifetimes on the order of half an hour for MeV energies. The electron loss rate show strong energy dependence with faster loss at higher energies, which suggest that this dropout event is dominated by quick and localized scattering process that prefers higher energy electrons. The estimated pitch angle diffusion rates from the model are then compared with in situ wave measurements from Van Allen Probes to uncover the underlying wave-particle-interaction mechanisms that are responsible for the fast electron precipitation. Comparing the resolved precipitation loss with the observed electron dropouts at high altitudes, our results will suggest the relative role of electron precipitation loss and outward radial diffusion to the radiation belt dropouts during storm and non-storm times, in addition to its energy and L dependence.

  20. Incorporating Allelic Dropout

    Czech Academy of Sciences Publication Activity Database

    Slovák, Dalibor

    2014-01-01

    Roč. 2, č. 1 (2014), s. 31-33 ISSN 1805-8698 Grant - others:SVV(CZ) 260034 Institutional support: RVO:67985807 Keywords : drop-out * peak height * DNA interpretation Subject RIV: IN - Informatics, Computer Science http://www.ijbh.org/ijbh2014-1.pdf

  1. Far-infrared constraints on the contamination by dust-obscured galaxies of high-z dropout searches.

    OpenAIRE

    Boone, F.; Schaerer, D.; Pelló, R.; Lutz, D.; Weiss, A.; Egami, E.; Smail, I.; Rex, M.; Rawle, T.; Ivison, R.; Laporte, N.; Beelen, A.; Combes, F.; Blain, A.W.; Richard, J.

    2011-01-01

    The spectral energy distributions (SED) of dusty galaxies at intermediate redshift may look similar to very high-redshift galaxies in the optical/near infrared (NIR) domain. This can lead to the contamination of high-redshift galaxy searches based on broad-band optical/NIR photometry by lower redshift dusty galaxies because both kind of galaxies cannot be distinguished. The contamination rate could be as high as 50%. This work shows how the far-infrared (FIR) domain can help to recognize like...

  2. Does the Empirical Literature Inform Prevention of Dropout among Students with Emotional Disturbance? A Systematic Review and Call to Action

    Science.gov (United States)

    Sullivan, Amanda L.; Sadeh, Shanna

    2016-01-01

    For the past 30 years, the dropout rate for students with emotional disturbance has hovered around 50%, a rate substantially higher than the dropout rate for students with other disabilities and the general population. This systematic review evaluated the literature published between 1990 and 2013 on the effectiveness of dropout prevention and…

  3. Parental Background and University Dropout in Italy

    Science.gov (United States)

    Aina, Carmen

    2013-01-01

    Using longitudinal data drawn from the European Community Household Panel, this paper examines Italian university entry and dropout rates in the context of specific parental and family characteristics. We are interested in the effects of the household's cultural and financial conditions on shaping investment in tertiary education and its failure,…

  4. The impact of community schools on student dropout in pre-vocational education

    NARCIS (Netherlands)

    Heers, Marieke; Van Klaveren, Chris; Groot, Wim; van den Brink, Henriëtte Maassen

    2014-01-01

    Dropout prevention is highly ranked on the political agenda in many countries. It remains unclear, however, how dropout can be effectively reduced, as many different factors determine student dropout. Community schools recognize this and aim to modernize education such that it better accommodates

  5. The impact of community schools on student dropout in pre-vocational education

    NARCIS (Netherlands)

    Heers, M.; van Klaveren, C.; Groot, W.; Maassen van den Brink, H.

    2012-01-01

    Dropout prevention is highly ranked on the political agenda in many countries. It remains unclear, however, how dropout can be effectively reduced, as many different factors are determining student dropout. Community schools recognize this and modernize education such that it better accommodates

  6. Quantitative analysis of artifacts in 4D DSA: the relative contributions of beam hardening and scatter to vessel dropout behind highly attenuating structures

    Science.gov (United States)

    Hermus, James; Szczykutowicz, Timothy P.; Strother, Charles M.; Mistretta, Charles

    2014-03-01

    When performing Computed Tomographic (CT) image reconstruction on digital subtraction angiography (DSA) projections, loss of vessel contrast has been observed behind highly attenuating anatomy, such as dental implants and large contrast filled aneurysms. Because this typically occurs only in a limited range of projection angles, the observed contrast time course can potentially be altered. In this work, we have developed a model for acquiring DSA projections that models both the polychromatic nature of the x-ray spectrum and the x-ray scattering interactions to investigate this problem. In our simulation framework, scatter and beam hardening contributions to vessel dropout can be analyzed separately. We constructed digital phantoms with large clearly defined regions containing iodine contrast, bone, soft issue, titanium (dental implants) or combinations of these materials. As the regions containing the materials were large and rectangular, when the phantoms were forward projected, the projections contained uniform regions of interest (ROI) and enabled accurate vessel dropout analysis. Two phantom models were used, one to model the case of a vessel behind a large contrast filled aneurysm and the other to model a vessel behind a dental implant. Cases in which both beam hardening and scatter were turned off, only scatter was turned on, only beam hardening was turned on, and both scatter and beam hardening were turned on, were simulated for both phantom models. The analysis of this data showed that the contrast degradation is primarily due to scatter. When analyzing the aneurysm case, 90.25% of the vessel contrast was lost in the polychromatic scatter image, however only 50.5% of the vessel contrast was lost in the beam hardening only image. When analyzing the teeth case, 44.2% of the vessel contrast was lost in the polychromatic scatter image and only 26.2% of the vessel contrast was lost in the beam hardening only image.

  7. Social factors outside of family and school related to student dropout

    Directory of Open Access Journals (Sweden)

    Stepanović-Ilić Ivana

    2017-01-01

    Full Text Available The paper presents a systematisation of broader social factors affecting student dropout in Serbia from the framework of Bronfenbrenner’s approach. Although recognised by authors and commonly related to community and education as a system, these factors are rarely investigated. Starting from our previous research into dropout, focused primarily on family and school, this study is aimed at investigating community and systemic factors. The data were compiled by semi-structured interviews with respondents from the following groups (including relevant public statistical data: students who dropped out/are at risk and their parents; school principals and counsellors from schools with high and low attrition rates; teachers’, parents’ and students’ representatives from schools with high dropout rates; social workers in charge of schools with a low attrition rate; representatives of national educational institutions. The findings reveal that factors with a negative impact on children’s education dominate over supportive ones which could have a preventive effect on attrition. Negative influences exist in all social niches: in microsystems (peers prone to risky behaviour, poor neighbourhoods, in weak mesosystem connections of school and family with local institutions, in exosystems (undeveloped regions, up to the macrosystem level (legislative inefficiency, lack of cooperation within educational institutions and between governmental departments. Productive features were observed in mesosystem connections of schools as examples of good practice, as well as at macrosystem level in the form of recognising the dropout problem at the national level. Although preliminary, the obtained results provide useful guidelines for future investigations.

  8. University Students’ Tendencies Toward and Reasons Behind Dropout

    Directory of Open Access Journals (Sweden)

    Hüseyin ŞİMŞEK

    2013-04-01

    Full Text Available In this research conducted to investigate university students’ tendencies toward and reasons behind dropout, it was found that university students had a high level of tendency towards dropout (45%. This indicated that one out of two students wanted to drop out of school at least once for a reason. As a result, their tendencies toward dropout was due to personal factors as well as those related to family, friends, and school. The personal factors affecting tendency toward dropout were gender, academic performance, school attendance, out-of-school work, boredom at school, and discipline penalty. According to the results, the factors related to school were faculty type, level of satisfaction with administrative and teaching staff as well as with social activities, level of difficulty in the department, and willingness to choose faculty. Furthermore, in this study, a positive relationship was found between dropout tendency and possession of close friends who dropped out of school.

  9. Dropout is a problem in lifestyle intervention programs for overweight and obese infertile women: a systematic review

    NARCIS (Netherlands)

    Mutsaerts, M. A. Q.; Kuchenbecker, W. K. H.; Mol, B. W.; Land, J. A.; Hoek, A.

    2013-01-01

    What are the dropout rates in lifestyle intervention programs (LIPs) for overweight and obese infertile women and can intervention- or patient-related baseline factors associated with dropout be identified in these women? The median dropout rate was 24% in overweight and obese infertile women who

  10. Dropout is a problem in lifestyle intervention programs for overweight and obese infertile women : a systematic review

    NARCIS (Netherlands)

    Mutsaerts, M. A. Q.; Kuchenbecker, W. K. H.; Mol, B. W.; Land, J. A.; Hoek, A.

    What are the dropout rates in lifestyle intervention programs (LIPs) for overweight and obese infertile women and can intervention- or patient-related baseline factors associated with dropout be identified in these women? The median dropout rate was 24 in overweight and obese infertile women who

  11. Causes of Student Absenteeism and School Dropouts

    Science.gov (United States)

    Sahin, Seyma; Arseven, Zeynep; Kiliç, Abdurrahman

    2016-01-01

    The aim of the study is to investigate the causes of student absenteeism and school dropouts at primary, secondary and high school level in Düzce Province and to develop suggestions for solving these problems. A "case study" design, which is one of the qualitative research approaches, was used in this study. The study group consisted of…

  12. GOAL Academy: Giving Dropouts a Second Chance

    Science.gov (United States)

    Dicksteen, Lisa Napell

    2012-01-01

    The U.S. Department of Education's (ED) National Center for Education Statistics defines dropouts as "16- through 21-year-olds who are not enrolled in school and have not earned a high school credential (either a diploma or an equivalency credential such as a General Education Development (GED) certificate)." According to the feds, the…

  13. Impact of dropout of female volunteer community health workers: An exploration in Dhaka urban slums

    Directory of Open Access Journals (Sweden)

    Alam Khurshid

    2012-08-01

    Full Text Available Abstract Background The model of volunteer community health workers (CHWs is a common approach to serving the poor communities in developing countries. BRAC, a large NGO in Bangladesh, is a pioneer in this area, has been using female CHWs as core workers in its community-based health programs since 1977. After 25 years of implementing of the CHW model in rural areas, BRAC has begun using female CHWs in urban slums through a community-based maternal health intervention. However, BRAC experiences high dropout rates among CHWs suggesting a need to better understand the impact of their dropout which would help to reduce dropout and increase program sustainability. The main objective of the study was to estimate impact of dropout of volunteer CHWs from both BRAC and community perspectives. Also, we estimated cost of possible strategies to reduce dropout and compared whether these costs were more or less than the costs borne by BRAC and the community. Methods We used the ‘ingredient approach’ to estimate the cost of recruiting and training of CHWs and the so-called ‘friction cost approach’ to estimate the cost of replacement of CHWs after adapting. Finally, we estimated forgone services in the community due to CHW dropout applying the concept of the friction period. Results In 2009, average cost per regular CHW was US$ 59.28 which was US$ 60.04 for an ad-hoc CHW if a CHW participated a three-week basic training, a one-day refresher training, one incentive day and worked for a month in the community after recruitment. One month absence of a CHW with standard performance in the community meant substantial forgone health services like health education, antenatal visits, deliveries, referrals of complicated cases, and distribution of drugs and health commodities. However, with an additional investment of US$ 121 yearly per CHW BRAC could save another US$ 60 invested an ad-hoc CHW plus forgone services in the community. Conclusion Although CHWs

  14. Model-Free Adaptive Control Algorithm with Data Dropout Compensation

    Directory of Open Access Journals (Sweden)

    Xuhui Bu

    2012-01-01

    Full Text Available The convergence of model-free adaptive control (MFAC algorithm can be guaranteed when the system is subject to measurement data dropout. The system output convergent speed gets slower as dropout rate increases. This paper proposes a MFAC algorithm with data compensation. The missing data is first estimated using the dynamical linearization method, and then the estimated value is introduced to update control input. The convergence analysis of the proposed MFAC algorithm is given, and the effectiveness is also validated by simulations. It is shown that the proposed algorithm can compensate the effect of the data dropout, and the better output performance can be obtained.

  15. State-level high school completion rates: Concepts, measures, and trends.

    Directory of Open Access Journals (Sweden)

    John Robert Warren

    2005-12-01

    Full Text Available Since the mid 1970s the national rate at which incoming 9th graders have completed high school has fallen slowly but steadily; this is also true in 41 states. In 2002, about three in every four students who might have completed high school actually did so; in some states this figure is substantially lower. In this paper I review state-level measures of high school completion rates and describe and validate a new measure that reports these rates for 1975 through 2002. Existing measures based on the Current Population Survey are conceptually imperfect and statistically unreliable. Measures based on Common Core Data (CCD dropout information are unavailable for many states and have different conceptual weaknesses. Existing measures based on CCD enrollment and completion data are systematically biased by migration, changes in cohort size, and/or grade retention. The new CCD-based measure described here is considerably less biased, performs differently in empirical analyses, and gives a different picture of the dropout situation across states and over time.

  16. Treatment dropout in web-based cognitive behavioral therapy for patients with eating disorders.

    Science.gov (United States)

    Ter Huurne, Elke D; Postel, Marloes G; de Haan, Hein A; van der Palen, Job; DeJong, Cor A J

    2017-01-01

    Treatment dropout is an important concern in eating disorder treatments as it has negative implications for patients' outcome, clinicians' motivation, and research studies. Our main objective was to conduct an exploratory study on treatment dropout in a two-part web-based cognitive behavioral therapy with asynchronous therapeutic support. The analysis included 205 female patients with eating disorders. Reasons for dropout, treatment experiences, and predictors of dropout were analyzed. Overall treatment dropout was 37.6%, with 18.5% early dropout (before or during treatment part 1) and 19.0% late dropout (after part 1 or during part 2). Almost half of the participants identified personal circumstances as reason for dropout. The other participants mostly reported reasons related to the online delivery or treatment protocol. Predictors of early dropout included reporting less vigor and smoking at baseline and a longer average duration per completed treatment module of part 1. Late dropout was predicted by reporting less vigor at baseline and uncertainty about recommendation of the treatment to others after completion of treatment part 1. Generally, the web-based treatment and online therapeutic support were evaluated positively, although dropouts rated the treatment as significantly less helpful and effective than completers did. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  17. Impact of a Ninth-Grade Transition Program on Cumulative GPAs and Credits, Ninth-Grade Dropout Rates, and Student Satisfaction

    Science.gov (United States)

    Buhrman, B. R.

    2010-01-01

    Concerned educators have been implementing ninth-grade transition programs to help freshmen adjust to the demands in high school and to reduce ninth-grade failure rates. The purpose of this quasi-experimental quantitative study was to investigate the impact of a ninth-grade transition program. The research questions addressed impact on cumulative…

  18. Who Needs a Second Chance? The Challenge of Documenting K-12 Dropout and Why Adult Educators Should Be Concerned

    Science.gov (United States)

    Zachry, Elizabeth M.

    2010-01-01

    This literature review examines current practice in reporting school dropout rates and the impact that school dropout may have on adult education programs and policies. First, I investigate the five dropout estimates commonly reported by the U.S. Department of Education (USDOE), examining how these measures vary in their estimation of school…

  19. Predictors of treatment dropout in self-guided web-based interventions for depression: an 'individual patient data' meta-analysis.

    Science.gov (United States)

    Karyotaki, E; Kleiboer, A; Smit, F; Turner, D T; Pastor, A M; Andersson, G; Berger, T; Botella, C; Breton, J M; Carlbring, P; Christensen, H; de Graaf, E; Griffiths, K; Donker, T; Farrer, L; Huibers, M J H; Lenndin, J; Mackinnon, A; Meyer, B; Moritz, S; Riper, H; Spek, V; Vernmark, K; Cuijpers, P

    2015-10-01

    It is well known that web-based interventions can be effective treatments for depression. However, dropout rates in web-based interventions are typically high, especially in self-guided web-based interventions. Rigorous empirical evidence regarding factors influencing dropout in self-guided web-based interventions is lacking due to small study sample sizes. In this paper we examined predictors of dropout in an individual patient data meta-analysis to gain a better understanding of who may benefit from these interventions. A comprehensive literature search for all randomized controlled trials (RCTs) of psychotherapy for adults with depression from 2006 to January 2013 was conducted. Next, we approached authors to collect the primary data of the selected studies. Predictors of dropout, such as socio-demographic, clinical, and intervention characteristics were examined. Data from 2705 participants across ten RCTs of self-guided web-based interventions for depression were analysed. The multivariate analysis indicated that male gender [relative risk (RR) 1.08], lower educational level (primary education, RR 1.26) and co-morbid anxiety symptoms (RR 1.18) significantly increased the risk of dropping out, while for every additional 4 years of age, the risk of dropping out significantly decreased (RR 0.94). Dropout can be predicted by several variables and is not randomly distributed. This knowledge may inform tailoring of online self-help interventions to prevent dropout in identified groups at risk.

  20. Alternative education programmes and middle school dropout in Honduras

    Science.gov (United States)

    Marshall, Jeffery H.; Aguilar, Claudia R.; Alas, Mario; Castellanos, Renán Rápalo; Castro, Levi; Enamorado, Ramón; Fonseca, Esther

    2014-05-01

    Honduras has made steady progress in expanding post-primary school coverage in recent years, but many rural communities still do not provide a middle (lower secondary) school. As a result, Honduras has implemented a number of middle school alternative programmes designed to meet the needs of at-risk populations throughout the country. This article analyses dropout in three of the four main alternative lower secondary school programmes in Honduras over a three-year period for a cohort of roughly 5,500 students. The results show that these programmes are indeed reaching a vulnerable population in the country, but dropout rates are generally very high - upwards of 50 per cent in some cases - between Grades 7 and 9. Furthermore, even in the control school comparison samples made up of formal lower secondary schools, about 25 per cent of children leave school between Grades 7 and 9. The authors' analysis includes propensity score matching (PSM) methods that make more focused comparisons between students in alternative programmes and control samples. These results show that dropout rates in alternative programmes are not much different than in control schools, and only significant in one programme comparison, when taking into account family background characteristics like socioeconomic status (SES). Multivariate analysis within alternative programme samples finds that attrition is lower in those learning centres which have adopted key features of formal schools, such as university-educated teachers. The results highlight the tremendous variation in the alternative middle school sector in terms of programme features, school quality and student outcomes, as well as the challenges of expanding this sector to meet the growing demand for lower secondary schooling in Honduras.

  1. First-generation phosphodiesterase type 5 inhibitors dropout: a comprehensive review and meta-analysis.

    Science.gov (United States)

    Corona, G; Rastrelli, G; Burri, A; Serra, E; Gianfrilli, D; Mannucci, E; Jannini, E A; Maggi, M

    2016-11-01

    The discontinuation rate with phosphodiesterase type 5 inhibitors (PDE5i) remains very high. The aim of this study was to review and meta-analyze currently available data regarding dropout of the first-generation of PDE5i including sildenafil, vardenafil, and tadalafil. An extensive Medline Embase and Cochrane search was performed including the following words: 'PDE5i', 'discontinuation'. All observational studies reporting the dropout rate of PDE5i and its specific causes without any arbitrary restrictions were included. Out of 103 retrieved articles, 22 were included in the study. Retrieved trials included a total of 162,936 patients with a mean age of 58.8 ± 7.9 years. Prevalence of reported comorbid diabetes and hypertension were 27.7% and 36.9%, respectively. PDE5i were associated with a mean discontinuation rate of 4% per month (almost 50% after one year). This rate was higher in younger subjects and in those reporting a higher prevalence of associated morbidities. Six main reasons of PDE5i dropout were identified in the evaluated trials. Partner-related problems and lack of efficacy represented the most important reasons for PDE5i discontinuation, although no significant difference among factors was detected. In conclusion, despite their high efficacy and easy administration, the discontinuation rate and dissatisfaction with PDE5i are still very high. Our data showed that no single factor plays a major role in PDE5i dropout, suggesting that the discontinuation rate is usually because of a combination of both medical problems and psychosocial and relational factors. © 2016 American Society of Andrology and European Academy of Andrology.

  2. THE ESTIMATION OF STAR FORMATION RATES AND STELLAR POPULATION AGES OF HIGH-REDSHIFT GALAXIES FROM BROADBAND PHOTOMETRY

    International Nuclear Information System (INIS)

    Lee, Seong-Kook; Ferguson, Henry C.; Somerville, Rachel S.; Wiklind, Tommy; Giavalisco, Mauro

    2010-01-01

    We explore methods to improve the estimates of star formation rates and mean stellar population ages from broadband photometry of high-redshift star-forming galaxies. We use synthetic spectral templates with a variety of simple parametric star formation histories to fit broadband spectral energy distributions. These parametric models are used to infer ages, star formation rates, and stellar masses for a mock data set drawn from a hierarchical semi-analytic model of galaxy evolution. Traditional parametric models generally assume an exponentially declining rate of star formation after an initial instantaneous rise. Our results show that star formation histories with a much more gradual rise in the star formation rate are likely to be better templates, and are likely to give better overall estimates of the age distribution and star formation rate distribution of Lyman break galaxies (LBGs). For B- and V-dropouts, we find the best simple parametric model to be one where the star formation rate increases linearly with time. The exponentially declining model overpredicts the age by 100% and 120% for B- and V-dropouts, on average, while for a linearly increasing model, the age is overpredicted by 9% and 16%, respectively. Similarly, the exponential model underpredicts star formation rates by 56% and 60%, while the linearly increasing model underpredicts by 15% and 22%, respectively. For U-dropouts, the models where the star formation rate has a peak (near z ∼ 3) provide the best match for age-overprediction is reduced from 110% to 26%-and star formation rate-underprediction is reduced from 58% to 22%. We classify different types of star formation histories in the semi-analytic models and show how the biases behave for the different classes. We also provide two-band calibration formulae for stellar mass and star formation rate estimations.

  3. Exploring First-Term Online College Dropout Relative to High School Certification, Gap Years, and Computer Literacy

    Science.gov (United States)

    Suydan, Ava Birgitte

    2014-01-01

    Despite university efforts to decrease the number of students dropping out of college, attrition of online students occurs at an annual rate of 50% or more (Wang & Wu, 2004). Educational leaders understand the increased demand for online programs and courses because of students' requirements of convenience and flexibility (Kuo, Walker,…

  4. Individual, Social, and Family Factors Associated with High School Dropout among Low-SES Youth: Differential Effects as a Function of Immigrant Status

    Science.gov (United States)

    Archambault, Isabelle; Janosz, Michel; Dupéré, Véronique; Brault, Marie-Christine; Andrew, Marie Mc

    2017-01-01

    Background: In most Western countries, the individual, social, and family characteristics associated with students' dropout in the general population are well documented. Yet, there is a lack of large-scale studies to establish whether these characteristics have the same influence for students with an immigrant background. Aims: The first aim of…

  5. 78 FR 11803 - Proposed Waiver and Extension of the Project Period for the National Dropout Prevention Center...

    Science.gov (United States)

    2013-02-20

    ... the National Dropout Prevention Center for Students With Disabilities [Catalog of Federal Domestic... would enable the currently funded National Dropout Prevention Center for Students with Disabilities to... about dropout prevention for students with disabilities, and to develop a series of high-quality...

  6. Creating a Culture for High-Performing Schools: A Comprehensive Approach to School Reform and Dropout Prevention. Second Edition

    Science.gov (United States)

    Bulach, Cletus R.; Lunenberg, Fred C.; Potter, Les

    2011-01-01

    A high-performing school is described as one where student achievement is high and student and teacher absenteeism is low. Student behavior is such that teachers seldom have to control them or tell them what to do. This results in greater time on task, higher teacher morale, low teacher absenteeism, and improved parental support. One other…

  7. Meta-analysis of Dropout in Treatments for Post-traumatic Stress Disorder

    Science.gov (United States)

    Imel, Zac E.; Laska, Kevin; Jakcupcak, Matthew; Simpson, Tracy L.

    2013-01-01

    Objective Many patients dropout of treatments for Post-traumatic stress disorder (PTSD) and some clinicians believe that ‘trauma focused’ treatments increase dropout. Method We conducted a meta-analysis of dropout among active treatments in clinical trials for PTSD (42 studies; 17 direct comparisons). Results The average dropout rate was 18%, but it varied significantly across studies. Group modality and greater number of sessions, but not trauma focus, predicted increased dropout. When the meta-analysis was restricted to direct comparisons of active treatments, there were no differences in dropout. Differences in trauma focus between treatments in the same study did not predict dropout. However, trauma focused treatments resulted in higher dropout as compared to Present Centered Therapy (PCT) – a treatment originally designed as a control, but now listed as a research supported intervention for PTSD. Conclusion Dropout varies between active interventions for PTSD across studies, but differences are primarily driven by differences between studies. There do not appear to be systematic differences across active interventions when they are directly compared in the same study. The degree of clinical attention placed on the traumatic event does not appear to be a primary cause of dropout from active treatments. However comparisons of PCT may be an exception to this general pattern, perhaps due to a restriction of variability in trauma focus among comparisons of active treatments. More research is needed comparing trauma focused interventions to trauma avoidant treatments such as PCT. PMID:23339535

  8. Internet-based motivation program for women with eating disorders: eating disorder pathology and depressive mood predict dropout.

    Science.gov (United States)

    von Brachel, Ruth; Hötzel, Katrin; Hirschfeld, Gerrit; Rieger, Elizabeth; Schmidt, Ulrike; Kosfelder, Joachim; Hechler, Tanja; Schulte, Dietmar; Vocks, Silja

    2014-03-31

    One of the main problems of Internet-delivered interventions for a range of disorders is the high dropout rate, yet little is known about the factors associated with this. We recently developed and tested a Web-based 6-session program to enhance motivation to change for women with anorexia nervosa, bulimia nervosa, or related subthreshold eating pathology. The aim of the present study was to identify predictors of dropout from this Web program. A total of 179 women took part in the study. We used survival analyses (Cox regression) to investigate the predictive effect of eating disorder pathology (assessed by the Eating Disorders Examination-Questionnaire; EDE-Q), depressive mood (Hopkins Symptom Checklist), motivation to change (University of Rhode Island Change Assessment Scale; URICA), and participants' age at dropout. To identify predictors, we used the least absolute shrinkage and selection operator (LASSO) method. The dropout rate was 50.8% (91/179) and was equally distributed across the 6 treatment sessions. The LASSO analysis revealed that higher scores on the Shape Concerns subscale of the EDE-Q, a higher frequency of binge eating episodes and vomiting, as well as higher depression scores significantly increased the probability of dropout. However, we did not find any effect of the URICA or age on dropout. Women with more severe eating disorder pathology and depressive mood had a higher likelihood of dropping out from a Web-based motivational enhancement program. Interventions such as ours need to address the specific needs of women with more severe eating disorder pathology and depressive mood and offer them additional support to prevent them from prematurely discontinuing treatment.

  9. Internet-Based Motivation Program for Women With Eating Disorders: Eating Disorder Pathology and Depressive Mood Predict Dropout

    Science.gov (United States)

    Hirschfeld, Gerrit; Rieger, Elizabeth; Schmidt, Ulrike; Kosfelder, Joachim; Hechler, Tanja; Schulte, Dietmar; Vocks, Silja

    2014-01-01

    Background One of the main problems of Internet-delivered interventions for a range of disorders is the high dropout rate, yet little is known about the factors associated with this. We recently developed and tested a Web-based 6-session program to enhance motivation to change for women with anorexia nervosa, bulimia nervosa, or related subthreshold eating pathology. Objective The aim of the present study was to identify predictors of dropout from this Web program. Methods A total of 179 women took part in the study. We used survival analyses (Cox regression) to investigate the predictive effect of eating disorder pathology (assessed by the Eating Disorders Examination-Questionnaire; EDE-Q), depressive mood (Hopkins Symptom Checklist), motivation to change (University of Rhode Island Change Assessment Scale; URICA), and participants’ age at dropout. To identify predictors, we used the least absolute shrinkage and selection operator (LASSO) method. Results The dropout rate was 50.8% (91/179) and was equally distributed across the 6 treatment sessions. The LASSO analysis revealed that higher scores on the Shape Concerns subscale of the EDE-Q, a higher frequency of binge eating episodes and vomiting, as well as higher depression scores significantly increased the probability of dropout. However, we did not find any effect of the URICA or age on dropout. Conclusions Women with more severe eating disorder pathology and depressive mood had a higher likelihood of dropping out from a Web-based motivational enhancement program. Interventions such as ours need to address the specific needs of women with more severe eating disorder pathology and depressive mood and offer them additional support to prevent them from prematurely discontinuing treatment. PMID:24686856

  10. Efficient batchwise dropout training using submatrices

    OpenAIRE

    Graham, Ben; Reizenstein, Jeremy; Robinson, Leigh

    2015-01-01

    Dropout is a popular technique for regularizing artificial neural networks. Dropout networks are generally trained by minibatch gradient descent with a dropout mask turning off some of the units---a different pattern of dropout is applied to every sample in the minibatch. We explore a very simple alternative to the dropout mask. Instead of masking dropped out units by setting them to zero, we perform matrix multiplication using a submatrix of the weight matrix---unneeded hidden units are neve...

  11. Exploring Regional and Institutional Factors of International Students' Dropout: The South Korea Case

    Science.gov (United States)

    Jung, Jisun; Kim, Yangson

    2018-01-01

    With an increasing number of international students in South Korea, the issue of retaining these students and reducing their dropout rates has become important. This study explores the multilevel factors that affect the institutional dropout rate among international students in Korea. The research questions are as follows: (a) to what extent do…

  12. Dropout in the lower tracks of Dutch secondary education : Predictor variables and variation among schools

    NARCIS (Netherlands)

    Luyten, H; Bosker, R.J.; Dekkers, H; Derks, A

    2003-01-01

    This study analyses the data from a large-scale longitudinal investigation into the effect of both school and student characteristics on the dropout rate for students in lower secondary education in The Netherlands. Dropout rates were found to vary significantly between schools, but only a single

  13. Understanding High Rate Behavior Through Low Rate Analog

    Science.gov (United States)

    2014-04-28

    challenges in high rate character- isation of polymers. The most important is that, owing to their low stress wavespeed, the structural response of...box’ tool, to provide supporting date for the rate dependent mechanical character- isation . Experiments were performed on a TA instruments Q800

  14. CAUSES AND CONSEQUENCES OF THE SCHOOL IN HIGH SCHOOL DROPOUT: CASE UNIVERSIDAD AUTÓNOMA DE SINALOA

    Directory of Open Access Journals (Sweden)

    Rosalva Ruiz-Ramírez

    2014-07-01

    Full Text Available The present investigation has the objective to establish the personal, economic and social causes and consequences that create school desertion of high school in Universidad Autónoma de Sinaloa (UAS. The investigation took place in the high school located in the municipality of El Fuerte, Sinaloa, in the academic unit (UA of San Blas and its extensions The Constancia and The Higueras of the Natoches in 2013. A mixed approach was used to analyze qualitative and quantitative information; the studied population was 18 women and 17 men deserters of the school cycle 2011-2012, ten teachers, four directors and twenty non-deserting students. In the results one can see that the principal factor for school desertion was the personnel to be married and not approving classes. The main consequence was economic, highlighting that the poverty cycle is hard to break.

  15. Experimental control of power dropouts by current modulation in a semiconductor laser with optical feedback

    International Nuclear Information System (INIS)

    Ticos, Catalin M; Andrei, Ionut R; Pascu, Mihail L; Bulinski, Mircea

    2011-01-01

    The injection current of an external-cavity semiconductor laser working in a regime of low-frequency fluctuations (LFFs) is modulated at several MHz. The rate of power dropouts in the laser emission is correlated with the amplitude and frequency of the modulating signal. The occurrence of dropouts becomes more regular when the laser is driven at 7 MHz, which is close to the dominant frequency of dropouts in the solitary laser. Driving the laser at 10 MHz also induces dropouts with a periodicity of 0.1 μs, resulting in LFFs with two dominant frequencies.

  16. Dropout from individual psychotherapy for major depression: A meta-analysis of randomized clinical trials.

    Science.gov (United States)

    Cooper, Andrew A; Conklin, Laren R

    2015-08-01

    Dropout from mental health treatment poses a substantial problem, but rates vary substantially across studies and diagnoses. Focused reviews are needed to provide more detailed estimates for specific areas of research. Randomized clinical trials involving individual psychotherapy for unipolar depression are ubiquitous and important, but empirical data on average dropout rates from these studies is lacking. We conducted a random-effects meta-analysis of 54 such studies (N=5852) including 80 psychotherapy conditions, and evaluated a number of predictors of treatment- and study-level dropout rates. Our overall weighted dropout estimates were 19.9% at the study level, and 17.5% for psychotherapy conditions specifically. Therapy orientation did not significantly account for variance in dropout estimates, but estimates were significantly higher in psychotherapy conditions with more patients of minority racial status or with comorbid personality disorders. Treatment duration was also positively associated with dropout rates at trend level. Studies with an inactive control comparison had higher dropout rates than those without such a condition. Limitations include the inability to test certain potential predictors (e.g., socioeconomic status) due to infrequent reporting. Overall, our findings suggest the need to consider how specific patient and study characteristics may influence dropout rates in clinical research on individual therapy for depression. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. The impact of community schools on student dropout in pre-vocational education

    OpenAIRE

    Heers, M.; van Klaveren, C.; Groot, W.; Maassen van den Brink, H.

    2012-01-01

    Dropout prevention is highly ranked on the political agenda in many countries. It remains unclear, however, how dropout can be effectively reduced, as many different factors are determining student dropout. Community schools recognize this and modernize education such that it better accommodates students' personal needs. As a result these schools cooperate more with external organizations, stimulate parental involvement in the educational process and organize more extracurricular activities. ...

  18. Dropout policies and trends for students with and without disabilities.

    Science.gov (United States)

    Kemp, Suzanne E

    2006-01-01

    Students with and without disabilities are dropping out of school at an alarming rate. However, the precise extent of the problem remains elusive because individual schools, school districts, and state departments of education often use different definitional criteria and calculation methods. In addition, specific reasons why students drop out continues to be speculative and minimal research exists validating current dropout prevention programs for students with and without disabilities. This study examined methods secondary school principals used to calculate dropout rates, reasons they believed students dropped out of school, and what prevention programs were being used for students with and without disabilities. Results indicated that school districts used calculation methods that minimized dropout rates, students with and without disabilities dropped out for similar reasons, and few empirically validated prevention programs were being implemented. Implications for practice and directions for future research are discussed.

  19. An Imputation Model for Dropouts in Unemployment Data

    Directory of Open Access Journals (Sweden)

    Nilsson Petra

    2016-09-01

    Full Text Available Incomplete unemployment data is a fundamental problem when evaluating labour market policies in several countries. Many unemployment spells end for unknown reasons; in the Swedish Public Employment Service’s register as many as 20 percent. This leads to an ambiguity regarding destination states (employment, unemployment, retired, etc.. According to complete combined administrative data, the employment rate among dropouts was close to 50 for the years 1992 to 2006, but from 2007 the employment rate has dropped to 40 or less. This article explores an imputation approach. We investigate imputation models estimated both on survey data from 2005/2006 and on complete combined administrative data from 2005/2006 and 2011/2012. The models are evaluated in terms of their ability to make correct predictions. The models have relatively high predictive power.

  20. Dropouts and Compliance in Exercise Interventions Targeting Bone Mineral Density in Adults: A Meta-Analysis of Randomized Controlled Trials

    Directory of Open Access Journals (Sweden)

    George A. Kelley

    2013-01-01

    Full Text Available Background. Dropouts and compliance to exercise interventions targeting bone mineral density (BMD in adults are not well established. The purpose of this study was to address that gap. Methods. Meta-analysis of randomized controlled exercise intervention trials in adults ≥18 years of age. The primary outcomes were dropouts in the exercise and control groups as well as compliance to the exercise interventions. A random-effects model was used to pool results. Moderator analyses were conducted using mixed-effects ANOVA-like models and metaregression. Statistical significance was set at . Results. Thirty-six studies representing 3,297 participants (1,855 exercise, 1,442 control were included. Dropout rates in the exercise and control groups averaged 20.9% (95% CI 16.7%–25.9% and 15.9% (11.8%–21.1% while compliance to exercise was 76.3% (71.7%–80.3%. For both exercise and control groups, greater dropout rates were associated with studies conducted in the USA versus other countries, females versus males, premenopausal versus postmenopausal women, younger versus older participants, longer studies (controls only, and high- versus moderate-intensity training (exercisers only. Greater compliance to exercise was associated with being female, home- or facility-based exercise versus both, and shorter studies. Conclusion. These findings provide important information for researchers and practitioners with respect to exercise programs targeting BMD in adults.

  1. Exploring the Effects of Financial Aid on the Gap in Student Dropout Risks by Income Level

    Science.gov (United States)

    Chen, Rong; DesJardins, Stephen L.

    2008-01-01

    Using national survey data and discrete-time logit modeling, this research seeks to understand whether student aid mediates the relationship between parental income and student dropout behavior. Our analysis confirms that there is a gap in dropout rates for low-income students compared with their upper income peers, and suggests that some types of…

  2. Early Prediction of Student Dropout and Performance in MOOCSs Using Higher Granularity Temporal Information

    Science.gov (United States)

    Ye, Cheng; Biswas, Gautam

    2014-01-01

    Our project is motivated by the early dropout and low completion rate problem in MOOCs. We have extended traditional features for MOOC analysis with richer and higher granularity information to make more accurate predictions of dropout and performance. The results show that finer-grained temporal information increases the predictive power in the…

  3. Of Needles and Haystacks: Building an Accurate Statewide Dropout Early Warning System in Wisconsin

    Science.gov (United States)

    Knowles, Jared E.

    2015-01-01

    The state of Wisconsin has one of the highest four year graduation rates in the nation, but deep disparities among student subgroups remain. To address this the state has created the Wisconsin Dropout Early Warning System (DEWS), a predictive model of student dropout risk for students in grades six through nine. The Wisconsin DEWS is in use…

  4. Roads to Success in the Belgian French Community's Higher Education System: Predictors of Dropout and Degree Completion at the Université Libre De Bruxelles

    Science.gov (United States)

    Arias Ortiz, Elena; Dehon, Catherine

    2013-01-01

    In this paper we study the factors that influence both dropout and (4-year) degree completion throughout university by applying the set of discrete-time methods for competing risks in event history analysis, as described in Scott and Kennedy (2005). In the French-speaking Belgian community, participation rates are very high given that higher…

  5. Evidence on Dropout Phenomena at Universities

    DEFF Research Database (Denmark)

    Larsen, Malene Rode; Sommersel, Hanna Bjørnøy; Larsen, Michael Søgaard

    This publication is an excerpt from the full technical report ‘Dropout Phenomena at Universities: What is Dropout? Why does Dropout Occur? What Can be Done by the Universities to Prevent or Reduce it? A systematic review’, which was completed in April 2013. The purpose of this excerpt is to present...... the knowledge we have on dropout phenomena at European universities in a short, precise and comprehensible form to allow readers to orient themselves on the subject in a more readable manner....

  6. Infodemiological data of high-school drop-out related web searches in Canada correlating with real-world statistical data in the period 2004–2012

    Directory of Open Access Journals (Sweden)

    Anna Siri

    2016-12-01

    Examining the data broken down by gender, the correlations were higher and statistically significant in males than in females. GT-based data for drop-out resulted best modeled by an ARMA(1,0 model. Considering the cross correlation of Canadian regions, all of them resulted statistically significant at lag 0, apart from for New Brunswick, Newfoundland and Labrador and the Prince Edward island. A number or cross-correlations resulted statistically significant also at lag −1 (namely, Alberta, Manitoba, New Brunswick and Saskatchewan.

  7. Improving completion rates in adult education through social responsibility

    DEFF Research Database (Denmark)

    Wahlgren, Bjarne; Mariager-Anderson, Kristina

    2017-01-01

    Dropout is a serious problem within education. This article reports on an intervention project, titled “New Roles for the Teacher—Increased Completion Rates Through Social Responsibility,” which sought to reduce nonattendance and dropout rates in the Danish adult educational system by improving...... of reducing drop-out rates. As a consequence, the teachers acted more consistently and purposefully to prevent dropout, and a positive effect of the intervention on drop-out rates was documented....

  8. Are low back pain and low physical capacity risk indicators for dropout among recently qualified eldercare workers? A follow-up study.

    Science.gov (United States)

    Faber, Anne; Giver, Hanne; Strøyer, Jesper; Hannerz, Harald

    2010-12-01

    A high job turnover and dropout among eldercare workers has led to a significant shortage of qualified manpower in the Danish eldercare sector. The predictive effect of some non-work-related causes for leaving the eldercare sector 2 years after qualification, physical capacity, duration, and severity of previous low back pain, was investigated. A 2-year prospective cohort study of all the Danish eldercare workers, who finished their education during 2004 (n = 6347). Questionnaire data from 2004 were followed up by register data on attachment to labour market, educational status, and association to trade from Statistics Denmark in 2006. Data on physical capacity, duration, and severity of low back pain the last 12 months among the female participants were analysed by multinomial logistic regression to estimate odds-ratios for being either in the eldercare sector, in other health- and welfare sectors, in all other sectors, under education, or outside labour market, 2 years after qualification. Disability due to and duration of low back pain were significant predictors for dropout from the eldercare sector 2 years after qualification. Low physical capacity was not. Data on duration of low back pain suggest a trend towards a dose-response relationship: The longer the duration of low back pain, the higher odds for dropout. Low back pain and disability due to low back pain during the last year of education were independent predictors for dropout from the eldercare sector 2 years after qualification. However, low self-rated physical capacity did not predict job dropout or turnover.

  9. High burn rate solid composite propellants

    Science.gov (United States)

    Manship, Timothy D.

    High burn rate propellants help maintain high levels of thrust without requiring complex, high surface area grain geometries. Utilizing high burn rate propellants allows for simplified grain geometries that not only make production of the grains easier, but the simplified grains tend to have better mechanical strength, which is important in missiles undergoing high-g accelerations. Additionally, high burn rate propellants allow for a higher volumetric loading which reduces the overall missile's size and weight. The purpose of this study is to present methods of achieving a high burn rate propellant and to develop a composite propellant formulation that burns at 1.5 inches per second at 1000 psia. In this study, several means of achieving a high burn rate propellant were presented. In addition, several candidate approaches were evaluated using the Kepner-Tregoe method with hydroxyl terminated polybutadiene (HTPB)-based propellants using burn rate modifiers and dicyclopentadiene (DCPD)-based propellants being selected for further evaluation. Propellants with varying levels of nano-aluminum, nano-iron oxide, FeBTA, and overall solids loading were produced using the HTPB binder and evaluated in order to determine the effect the various ingredients have on the burn rate and to find a formulation that provides the burn rate desired. Experiments were conducted to compare the burn rates of propellants using the binders HTPB and DCPD. The DCPD formulation matched that of the baseline HTPB mix. Finally, GAP-plasticized DCPD gumstock dogbones were attempted to be made for mechanical evaluation. Results from the study show that nano-additives have a substantial effect on propellant burn rate with nano-iron oxide having the largest influence. Of the formulations tested, the highest burn rate was a 84% solids loading mix using nano-aluminum nano-iron oxide, and ammonium perchlorate in a 3:1(20 micron: 200 micron) ratio which achieved a burn rate of 1.2 inches per second at 1000

  10. Correlates of school dropout and absenteeism among adolescent girls from marginalized community in north Karnataka, south India.

    Science.gov (United States)

    Prakash, Ravi; Beattie, Tara; Javalkar, Prakash; Bhattacharjee, Parinita; Ramanaik, Satyanarayana; Thalinja, Raghavendra; Murthy, Srikanta; Davey, Calum; Blanchard, James; Watts, Charlotte; Collumbien, Martine; Moses, Stephen; Heise, Lori; Isac, Shajy

    2017-12-01

    Secondary education among lower caste adolescent girls living in rural Karnataka, South India, is characterized by high rates of school drop-out and absenteeism. A cross-sectional baseline survey (N=2275) was conducted in 2014 as part of a cluster-randomized control trial among adolescent girls (13-14 year) and their families from marginalized communities in two districts of north Karnataka. Bivariate and multivariate logistic regression models were used. Overall, 8.7% girls reported secondary school dropout and 8.1% reported frequent absenteeism (past month). In adjusted analyses, economic factors (household poverty; girls' work-related migration), social norms and practices (child marriage; value of girls' education), and school-related factors (poor learning environment and bullying/harassment at school) were associated with an increased odds of school dropout and absenteeism. Interventions aiming to increase secondary school retention among marginalized girls may require a multi-level approach, with synergistic components that address social, structural and economic determinants of school absenteeism and dropout. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  11. High-rate lithium thionyl chloride cells

    Science.gov (United States)

    Goebel, F.

    1982-03-01

    A high-rate C cell with disc electrodes was developed to demonstrate current rates which are comparable to other primary systems. The tests performed established the limits of abuse beyond which the cell becomes hazardous. Tests include: impact, shock, and vibration tests; temperature cycling; and salt water immersion of fresh cells.

  12. Lithium thionyl chloride high rate discharge

    Science.gov (United States)

    Klinedinst, K. A.

    1980-04-01

    Improvements in high rate lithium thionyl chloride power technology achieved by varying the electrolyte composition, operating temperature, cathode design, and cathode composition are discussed. Discharge capacities are plotted as a function of current density, cell voltage, and temperature.

  13. Concomitant chemoradiotherapy with high dose rate brachytherapy ...

    African Journals Online (AJOL)

    Concomitant chemoradiotherapy with high dose rate brachytherapy as a definitive treatment modality for locally advanced cervical cancer. T Refaat, A Elsaid, N Lotfy, K Kiel, W Small Jr, P Nickers, E Lartigau ...

  14. The High Cost of Failing to Reform Public Education in Indiana. School Choice Issues in the State

    Science.gov (United States)

    Gottlob, Brian J.

    2006-01-01

    This study documents the public costs of high school dropouts in Indiana, and examines how school choice would provide large public benefits by increasing the graduation rate in Indiana public schools. It calculates the annual cost of high school dropouts in Indiana due to lower state income tax payments, increased reliance on Medicaid, and…

  15. Factors associated with dropout among patients in opioid maintenance treatment (OMT) and predictors of re-entry. A national registry-based study.

    Science.gov (United States)

    Bukten, Anne; Skurtveit, Svetlana; Waal, Helge; Clausen, Thomas

    2014-10-01

    Retention in treatment is often highlighted as one of the key indicators of success in opioid maintenance treatment (OMT). To identify factors associated with long-term retention in opioid maintenance treatment and to analyse predictors of subsequent treatment episodes. Treatment retention and re-entry were examined for a national cohort of patients admitted to OMT in Norway in the period 1997-2003. Multivariate Cox regression models were used to investigate factors associated with treatment dropout 18months after treatment entry. The 18month retention rate among patients admitted to OMT in Norway (n=2431) was 65.8% (n=1599). Dropout from OMT within 18months was associated with younger age (HR 0.97 [0.96-0.98]), high levels of general pre-treatment criminal offences (HR 1.66 [1.32-2.09]) and having drug-related offences during the 30days prior to dropout (HR 1.80 [1.36-2.38]). Of the patients who dropped out (n=832), 42.7% (n=355) were re-engaged in subsequent treatment episodes. Pre-treatment criminal offences were associated with increased odds for treatment re-entry, whereas being younger and having drug-related offences during the first OMT episode were associated with lower odds for re-engagement in OMT. Gender was not associated with treatment dropout and re-entry. High levels of pre-treatment criminal offences and drug offences during the 30days prior to dropout were associated with treatment dropout. Efforts to increase support services to these patients may contribute to higher rates of retention in OMT. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Reexamining Gifted Underachievement and Dropout through the Lens of Student Engagement

    Science.gov (United States)

    Landis, Rebecca N.; Reschly, Amy L.

    2013-01-01

    The issue of high school dropout has long concerned policy makers, educational professionals, and the general public. In the gifted literature, this concern is no less pressing. Student engagement is becoming an increasingly discussed construct for conceptualizing the dropout phenomenon and designing appropriate interventions to prevent this…

  17. Psychological well-being as a predictor of dropout among recently qualified Danish eldercare workers.

    Science.gov (United States)

    Giver, Hanne; Faber, Anne; Hannerz, Harald; Strøyer, Jesper; Rugulies, Reiner

    2010-05-01

    The eldercare sector is characterized by a shortage of labour and a high turnover rate, which constitutes a major challenge for the ageing societies of western Europe. The aim of the present study was to investigate if a low level of psychological well-being at the time of graduation predicts dropout among eldercare workers two years later. We included 4,968 female eldercare trainees in this prospective study, recruited from 27 of the 28 Danish colleges for eldercare. Psychological well-being in 2004 was measured with the five-item Mental Health Inventory (MHI-5) of the 36-item Short-Form Health Survey (SF-36). We linked the survey data with national register data to obtain information about labour market attachment two years after qualification. In 2006, 37% of all participants had left the eldercare sector. Compared to participants with high psychological well-being at baseline, participants with medium and low psychological well-being were more likely to dropout to sectors unrelated to health and welfare (odds ratio (OR) 1.40 (95% confidence interval (95% CI) = 1.06-1.85) and 1.66 (95% CI = 1.27-2.19), respectively). They were also more likely to drop out of the labour market (OR 1.48 (95% CI = 1.08-2.04) and 1.60 (95% CI = 1.12-2.20), respectively). Psychological well-being was not related to dropout to other health- and welfare sectors or dropout to further education. The fact that more than one third of all participants had left the eldercare sector two years after qualification demonstrates the importance of retention initiatives early in working life. In addition a focus on psychological well-being among eldercare workers should be considered.

  18. The Hegemonic Curriculum and School Dropout: The Newfoundland Case.

    Science.gov (United States)

    Gedge, Joseph L.

    1991-01-01

    Confronted by a disturbing dropout rate and low student achievement, the Newfoundland (Canada) government is attempting to rationalize organizational restructuring and curriculum reform based on a centralized core academic curriculum aimed at college entrance. This article argues for an expanded, hegemonic curriculum that is organic to the…

  19. El problema del abandono de los estudios universitarios. [The dropout problem in university study

    Directory of Open Access Journals (Sweden)

    Lidia Cabrera

    2006-07-01

    Full Text Available This article focuses on the dropout of university students, which in some cases can be as high as 50%. This study presents and analyses the dropout rates that are found in several Spanish universities. Using the results of national and international studies as background and the findings from our own investigation, we present a theoretical framework that identifies the definition of dropouts, the causes, the explanatory models and solutions used to understand this issue. The article concludes by presenting a critical perspective of university learning in relation to the social role that universities represent, and addresses the actual processes of change, particularly in light of the European convergence. En este artículo se analiza el fenómeno problemático del abandono de los estudios universitarios, que alcanza hasta el 50% en algunas titulaciones. Para ello, partimos de la presentación y análisis de los porcentajes de abandono de distintas universidades españolas. Posteriormente, al amparo de distintos estudios nacionales e internacionales, y nuestros resultados de investigación, elaboramos un perfil teórico que contempla: definición, causas, modelos explicativos y soluciones. Finalmente, ofrecemos una perspectiva crítica de la enseñanza universitaria, en relación al papel social que esta representa, y en relación a los actuales procesos de cambio, sobre todo el proceso de convergencia europea.

  20. High Strain Rate Characterisation of Composite Materials

    DEFF Research Database (Denmark)

    Eriksen, Rasmus Normann Wilken

    -reinforced polymers, were considered, and it was first shown that the loading history controls equilibrium process. Then the High-speed servo-hydraulic test machine was analysed in terms its ability to create a state of constant strain rate in the specimen. The invertible inertial forces in the load train prevented...... from designing and constructing a high-speed servo-hydraulic test machine and by performing a comprehensive test series. The difficulties encountered in the test work could be addressed with the developed analysis. The conclusion was that the High-speed servo-hydraulic test machine is less suited...... for testing fibre-reinforced polymers due to their elastic behaviour and low strain to failure. This is problematic as the High-speed servo-hydraulic test machine closes the gap between quasi-static tests rates and lower strain rates, which are achievable with the Split Hopkinson Pressure Bar. The Split...

  1. Creating an Early Warning System: Predictors of Dropout in Delaware. REL Mid-Atlantic Technical Assistance Brief. REL MA 1.2.75-10

    Science.gov (United States)

    Uekawa, Kazuaki; Merola, Stacey; Fernandez, Felix; Porowski, Allan

    2010-01-01

    This Technical Brief presents an historical analysis of key indicators of dropout for Delaware students in grades 9-12. Cut points for key risk indicators of high school dropout for the State of Delaware are provided. Using data provided by the Delaware Department of Education (DDOE), relationships between student dropout and several student…

  2. A review of mental health treatment dropout by ethnic minority youth.

    Science.gov (United States)

    de Haan, Anna M; Boon, Albert E; de Jong, Joop T V M; Vermeiren, Robert R J M

    2018-02-01

    A large proportion of treatments in youth mental health care are prematurely terminated by the patient. Treatment dropout can have severe consequences. Since ethnic minority youth are treated less often for mental disorders than other youth, it is important to analyse their risk for dropout and to determine if there are ethnicity-specific determinants. This review aimed to provide an overview of the findings from empirical studies on child and adolescent therapy dropout by ethnic minority and to determine if there were ethnicity-specific dropout determinants. An extensive literature search was performed to locate relevant journal articles. Identified articles were inspected for relevant references and these articles were then included in the meta-analysis. A total of 27 studies were accepted for analysis. The results showed that ethnic minority patients have a higher risk of treatment dropout than ethnic majority patients and that dropout rates are ethnically specific. Several differences in dropout predictors among the ethnic groups were found. In spite of diverse results, review limitations, and the lack of several key variables in the available research, some clinical recommendations are made. The review indicates that to prevent dropout, therapists should pay attention to variables such as ethnic background, therapist-patient ethnic match, and the quality of the therapeutic relationship.

  3. Progress Is No Accident: Why ESEA Can't Backtrack on High School Graduation Rates

    Science.gov (United States)

    Alliance for Excellent Education, 2015

    2015-01-01

    In conjunction with the White House Next Gen High School Summit on November 10, a new report finds that the number of high school dropouts decreased from 1 million in 2008 to approximately 750,000 in 2012. The report, released by the Alliance for Excellent Education, America's Promise Alliance, Civic Enterprises, and Everyone Graduates Center,…

  4. Thrombus Formation at High Shear Rates.

    Science.gov (United States)

    Casa, Lauren D C; Ku, David N

    2017-06-21

    The final common pathway in myocardial infarction and ischemic stroke is occlusion of blood flow from a thrombus forming under high shear rates in arteries. A high-shear thrombus forms rapidly and is distinct from the slow formation of coagulation that occurs in stagnant blood. Thrombosis at high shear rates depends primarily on the long protein von Willebrand factor (vWF) and platelets, with hemodynamics playing an important role in each stage of thrombus formation, including vWF binding, platelet adhesion, platelet activation, and rapid thrombus growth. The prediction of high-shear thrombosis is a major area of biofluid mechanics in which point-of-care testing and computational modeling are promising future directions for clinically relevant research. Further research in this area will enable identification of patients at high risk for arterial thrombosis, improve prevention and treatment based on shear-dependent biological mechanisms, and improve blood-contacting device design to reduce thrombosis risk.

  5. Dropout is a problem in lifestyle intervention programs for overweight and obese infertile women: a systematic review.

    Science.gov (United States)

    Mutsaerts, M A Q; Kuchenbecker, W K H; Mol, B W; Land, J A; Hoek, A

    2013-04-01

    What are the dropout rates in lifestyle intervention programs (LIPs) for overweight and obese infertile women and can intervention- or patient-related baseline factors associated with dropout be identified in these women? The median dropout rate was 24% in overweight and obese infertile women who participated in a LIP; clinical useful intervention or patient-related factors associated with dropout could not be identified. Overweight and obese infertile women might improve their chance of conception when they improve their lifestyle and lose weight. Dropout from LIPs reduces the chance of losing considerable weight and is therefore considered to be an important limiting factor of the success of LIPs. This systematic review included 15 studies published between January 1980 and December 2012. The included studies investigated the effect of LIPs for overweight and obese infertile women with infertility. From these studies, dropout rates and intervention- and patient-related baseline factors associated with dropout, as well as weight loss and pregnancy rates, were recorded. There were 15 studies identified, of which 10 reported dropout rates. The median dropout rate was 24% (range: 0-31%). Four studies reported baseline characteristics of women who dropped out, but modifiable predictors of dropout could not be identified. Weight loss and pregnancy rates were lower in women who dropped out than in women who completed the LIPs. There were limited numbers of studies investigating patient-related factors associated with dropout. The heterogeneity in the studies precluded us from drawing firm conclusions on the relation between the type of intervention and dropout. Dropout from LIPs is a major drawback because it predisposes to less weight loss and lower pregnancy rates. Identification of predictors of dropout is needed to identify overweight and obese infertile women who are prone for dropout. These women might benefit from extra support and monitoring, to potentially

  6. High frame rate synthetic aperture duplex imaging

    DEFF Research Database (Denmark)

    Stuart, Matthias Bo; Tomov, Borislav Gueorguiev; Pihl, Michael Johannes

    2013-01-01

    aperture flow imaging as demonstrated in this paper. Synthetic aperture, directional beamforming, and cross-correlation are used to produce B-mode and vector velocity images at high frame rates. The frame rate equals the effective pulse repetition frequency of each imaging mode. Emissions for making the B...... estimation is −1.8% and the relative standard deviation 5.4%. The approach can thus estimate both high and low velocities with equal accuracy and thereby makes it possible to present vector flow images with a high dynamic range. Measurements are made using the SARUS research scanner, a linear array......Conventional color flow images are limited in velocity range and can either show the high velocities in systole or be optimized for the lower diastolic velocities. The full dynamics of the flow is, thus, hard to visualize. The dynamic range can be significantly increased by employing synthetic...

  7. Work environment and school dropout

    DEFF Research Database (Denmark)

    Hansen, Claus D.; Andersen, Johan Hviid; Lund, Thomas

    Aim The aim of this presentation is to examine the possible impact of work environment (and especially psychosocial work environment) on school dropout. The questions raised are: to what extent do psychosocial work environment and especially the social relations between young apprentices...... and their colleagues and managers play a role in dropping out of upper secondary education? Methods A cohort of 3058 adolescents born in 1989 and a cohort of approximately 2000 young adults born in 1983 are used to examine the associations between work environment and subsequent dropout in upper secondary educational...... indicated that ‘being treated badly by superior’ was part of the reason for doing so. Further analyses show that reporting repetitive and monotonous work tasks increases the risk of dropping out (OR: 1.74) and that reporting bad working climate at ones work place increases the risk of considering...

  8. Baltimore District Tackles High Suspension Rates

    Science.gov (United States)

    Maxwell, Lesli A.

    2007-01-01

    This article reports on how the Baltimore District tackles its high suspension rates. Driven by an increasing belief that zero-tolerance disciplinary policies are ineffective, more educators are embracing strategies that do not exclude misbehaving students from school for offenses such as insubordination, disrespect, cutting class, tardiness, and…

  9. Endorectal high dose rate brachytherapy quality assurance

    International Nuclear Information System (INIS)

    Devic, S.; Vuong, T.; Evans, M.; Podgorsak, E.

    2008-01-01

    We describe our quality assurance method for preoperative high dose rate (HDR) brachytherapy of endorectal tumours. Reproduction of the treatment planning dose distribution on a daily basis is crucial for treatment success. Due to the cylindrical symmetry, two types of adjustments are necessary: applicator rotation and dose distribution shift along the applicator axis. (author)

  10. Retrospective cohort study of the South Tyneside Exercise Referral Scheme 2009-14: predictors of dropout and barriers to adherence.

    Science.gov (United States)

    Kelly, Michael C; Rae, Glen C; Walker, Diane; Partington, Sarah; Dodd-Reynolds, Caroline J; Caplan, Nick

    2017-12-01

    Exercise Referral Schemes (ERS) are a prevalent method of increasing physical activity levels. However, they suffer from participant dropout and research predicting dropout or barriers to adherence are limited. This study aimed to focus upon the effect of referral characteristics on dropout, dropout predictors and whether self-reported barriers to exercise predict dropout. ERS data from 2009 to 2014 were retrieved for analysis. Chi-squared and t-tests were used to investigate differences between referral characteristics, and logistic regression used to investigate dropout predictors. Of 6894 participants, 37.8% (n = 2608) dropped out within 6 weeks and 50.03% (n = 3449) by the final 12th week. More males adhered (P dropouts being significantly younger (P Dropout predictors were smoking (OR = 1.58, 95% CI: 1.29-1.93) or being a Tier 3 referral (OR = 1.47, 95% CI: 1.25-1.73). Increasing age (OR = 0.98, 95% CI: 0.98-0.99), drinking alcohol (OR = 0.82, 95% CI: 0.71-0.95), secondary care referrals (OR = 0.68, 95% CI: 0.52-0.90), having a lack of motivation (OR = 0.81, 95% CI: 0.69-0.95) or a lack of childcare (OR = 0.69, 95% CI: 0.50-0.95) decreased the likelihood of dropout. ERS dropout continues to be problematic. Smoking and having moderate-high comorbidities predicted dropout. Increasing age and patient-reported barriers of a lack of time or childcare decreased dropout risk. The reasons for dropout require further investigation. © 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

  11. Impact of therapist change after initial contact and traumatic burden on dropout in a naturalistic sample of inpatients with borderline pathology receiving dialectical behavior therapy.

    Science.gov (United States)

    Steuwe, Carolin; Berg, Michaela; Driessen, Martin; Beblo, Thomas

    2017-01-01

    This study focused on the predictors of therapy dropout in a naturalistic sample of patients with borderline pathology receiving dialectical behavior therapy (DBT) in an inpatient setting. We assumed that the change of the therapist between DBT-briefing and start of DBT-treatment as well as comorbid posttraumatic stress disorder (PTSD) and childhood trauma history were associated with elevated dropout. Eighty-nine participants with borderline pathology (≥ 3 borderline personality disorder criteria) receiving an inpatient DBT program completed a quality assurance questionnaire set assessing demographic information and pretreatment psychopathology during the days of their inpatient stay. Beyond that, changes of therapists were documented. The predictor analyses were investigated with generalized estimating equations. The dropout rate was 24.7%. A change of therapist between DBT-briefing and treatment as well as high childhood emotional abuse was associated with premature termination of treatment. Higher values of physical neglect during childhood were associated with a protective effect on treatment dropout. Surprisingly, this was also true for comorbid PTSD. This study supports the importance of therapy process variables as predictors of therapy dropout in borderline pathology. A change of therapist between DBT-briefing and treatment was associated with an increased vulnerability for dropping out of treatment and should therefore be avoided if possible. Against our hypotheses, a comorbid PTSD was even protective with regard to DBT dropout. Therefore, this severely suffering patient group should not be rejected from treatment assuming them to be too unstable for psychotherapy. However, results need to be replicated. ClinicalTrials.gov Identifier: NCT03018639, retrospectively registered on January 9, 2017.

  12. High strain rate behaviour of polypropylene microfoams

    Directory of Open Access Journals (Sweden)

    Martínez A.B.

    2012-08-01

    Full Text Available Microcellular materials such as polypropylene foams are often used in protective applications and passive safety for packaging (electronic components, aeronautical structures, food, etc. or personal safety (helmets, knee-pads, etc.. In such applications the foams which are used are often designed to absorb the maximum energy and are generally subjected to severe loadings involving high strain rates. The manufacture process to obtain polymeric microcellular foams is based on the polymer saturation with a supercritical gas, at high temperature and pressure. This method presents several advantages over the conventional injection moulding techniques which make it industrially feasible. However, the effect of processing conditions such as blowing agent, concentration and microfoaming time and/or temperature on the microstructure of the resulting microcellular polymer (density, cell size and geometry is not yet set up. The compressive mechanical behaviour of several microcellular polypropylene foams has been investigated over a wide range of strain rates (0.001 to 3000 s−1 in order to show the effects of the processing parameters and strain rate on the mechanical properties. High strain rate tests were performed using a Split Hopkinson Pressure Bar apparatus (SHPB. Polypropylene and polyethylene-ethylene block copolymer foams of various densities were considered.

  13. High strain rate behaviour of polypropylene microfoams

    Science.gov (United States)

    Gómez-del Río, T.; Garrido, M. A.; Rodríguez, J.; Arencón, D.; Martínez, A. B.

    2012-08-01

    Microcellular materials such as polypropylene foams are often used in protective applications and passive safety for packaging (electronic components, aeronautical structures, food, etc.) or personal safety (helmets, knee-pads, etc.). In such applications the foams which are used are often designed to absorb the maximum energy and are generally subjected to severe loadings involving high strain rates. The manufacture process to obtain polymeric microcellular foams is based on the polymer saturation with a supercritical gas, at high temperature and pressure. This method presents several advantages over the conventional injection moulding techniques which make it industrially feasible. However, the effect of processing conditions such as blowing agent, concentration and microfoaming time and/or temperature on the microstructure of the resulting microcellular polymer (density, cell size and geometry) is not yet set up. The compressive mechanical behaviour of several microcellular polypropylene foams has been investigated over a wide range of strain rates (0.001 to 3000 s-1) in order to show the effects of the processing parameters and strain rate on the mechanical properties. High strain rate tests were performed using a Split Hopkinson Pressure Bar apparatus (SHPB). Polypropylene and polyethylene-ethylene block copolymer foams of various densities were considered.

  14. Analyzing the Discourse of Dropouts and Resilient Students

    Science.gov (United States)

    Lessard, Anne; Butler-Kisber, Lynn; Fortin, Laurier; Marcotte, Diane

    2014-01-01

    The authors focused on high school students who were at risk of dropping out and examined why some of these students persevered and graduated while others ended up dropping out of school. Sixty resilient students and 80 dropouts participated in the study. Our results indicate that although learning difficulties were shared by participants, 4 types…

  15. High dose rate endobronchial brachytherapy - treatment technique

    International Nuclear Information System (INIS)

    Carvalho, Heloisa de Andrade; Aisen, Salim; Haddad, Cecilia Maria Kalil; Nadalin, Wladimir; Pedreira Junior, Wilson Leite; Chavantes, Maria Cristina

    1998-01-01

    High dose rate endobronchial brachytherapy is efficient in symptom relief due to obstructive endobronchial malignancies. However, it's role in survival improvement for patients with lung cancer is not yet established. The use of this treatment in increasing, specially in the developing countries. The purpose of this paper is to present the treatment technique used in the Radiotherapy Department of the Hospital da Clinicas, University of Sao Paulo, based on an experience of 60 cases treated with 180 procedures. Some practical suggestions and rules adopted in the Department are described. The severe complications rate is 6.7%, demonstrating an adequate patient selection associated with the technique utilized. (author)

  16. Electronics for very high rate tracking detectors

    International Nuclear Information System (INIS)

    Williams, H.H.; Dressnandt, N.; Ekenberg, T.; Gerds, E.J.; Newcomer, F.M.; Tedja, S.; Van Berg, R.; Van der Speigel, J.

    1995-01-01

    Results are presented on a system of electronics designed for very high rate tracking detectors at the SSC and LHC. The primary goal was a system for signal detection, time measurement, and readout for the straw tracker for SDC. An integrated circuit incorporating eight channels of amplifier-shaper-discriminator (including detector tail cancellation), and two different integrated circuits for time measurement are described. The performance of tracking measurements up to counting rates of 8 MHz per wire is reported, as well as preliminary results from a baseline restoration circuit. (orig.)

  17. Shifting problems and shifting policies to reduce student drop-out

    DEFF Research Database (Denmark)

    Jørgensen, Christian Helms

    2016-01-01

    , as well as the policies that have been implemented in pursuit of improving student retention. The review identifies two pervasive ways in which the drop-out problem has been framed in both policy and research. The first locates the drop-out problem with individual students, while the second locates...... finds that the rate of student drop-out has been a cause for ongoing concern among policy makers for more than a century, and that the framing of the problem has shifted considerably over time. The problem has variously been placed with the individual apprentice, the basic structure of vocational......Education policy generally places a premium on raising the level of education attained by the young generation ultimately heading towards the labour market. While the rate of enrolment in post-compulsory education has risen in most countries, so too has the rate of drop-out, in particular from...

  18. On the Inductive Bias of Dropout

    OpenAIRE

    Helmbold, David P.; Long, Philip M.

    2014-01-01

    Dropout is a simple but effective technique for learning in neural networks and other settings. A sound theoretical understanding of dropout is needed to determine when dropout should be applied and how to use it most effectively. In this paper we continue the exploration of dropout as a regularizer pioneered by Wager, et.al. We focus on linear classification where a convex proxy to the misclassification loss (i.e. the logistic loss used in logistic regression) is minimized. We show: (a) when...

  19. High strain rate studies in rock

    International Nuclear Information System (INIS)

    Grady, D.

    1977-01-01

    Dynamic compression studies using high velocity impact are usually considered to involve a catastrophic process of indeterminate loading rate by which a material is brough to a shock compressed state. Although this is frequently the case, methods are also available to control the rate of strain during the shock compression process. One of the most accurate of these methods makes use of the anomalous nonlinear elastic property of glass to transform an initial shock or step wave input into a ramp wave of known amplitude and duration. Fused silica is the most carefully calibrated material for this purpose and, when placed between the test specimen and the impact projectile, can provide loading strain rates in the range of 10 4 /s to 10 6 /s for final stress states of approximately 3.9 GPa or less.Ramp wave compression experiments have been conducted on dolomite at strain rates of 3 x 10 4 /s. Both initial yielding and subsequent deformation at this strain rate agrees well with previous shock wave studies (epsilon-dotapprox.10 6 /s) and differs substantially from quasi-static measurements (epsilon-dotapprox.10 -4 /s). The ramp wave studies have also uncovered a pressure-induced phase transition in dolomite initiating at 4.0 GPa

  20. Dynamic Output Feedback Control for Nonlinear Networked Control Systems with Random Packet Dropout and Random Delay

    Directory of Open Access Journals (Sweden)

    Shuiqing Yu

    2013-01-01

    Full Text Available This paper investigates the dynamic output feedback control for nonlinear networked control systems with both random packet dropout and random delay. Random packet dropout and random delay are modeled as two independent random variables. An observer-based dynamic output feedback controller is designed based upon the Lyapunov theory. The quantitative relationship of the dropout rate, transition probability matrix, and nonlinear level is derived by solving a set of linear matrix inequalities. Finally, an example is presented to illustrate the effectiveness of the proposed method.

  1. Factors associated with dropout in medical education: a literature review

    DEFF Research Database (Denmark)

    O'Neill, Lotte; Wallstedt, Birgitta; Eika, Berit

    2011-01-01

    Medical school dropout may have negative consequences for society, patients, the profession, schools and dropouts. To our knowledge, the literature dealing with dropout from medical school has never been systematically and critically appraised.......Medical school dropout may have negative consequences for society, patients, the profession, schools and dropouts. To our knowledge, the literature dealing with dropout from medical school has never been systematically and critically appraised....

  2. High repetition rate intense ion beam source

    International Nuclear Information System (INIS)

    Hammer, D.A.; Glidden, S.C.; Noonan, B.

    1992-01-01

    This final report describes a ≤ 150kV, 40kA, 100ns high repetition rate pulsed power system and intense ion beam source which is now in operation at Cornell University. Operation of the Magnetically-controlled Anode Plasma (MAP) ion diode at > 100Hz (burst mode for up to 10 pulse bursts) provides an initial look at repetition rate limitations of both the ion diode and beam diagnostics. The pulsed power systems are capable of ≥ 1kHz operation (up to 10 pulse bursts), but ion diode operation was limited to ∼100Hz because of diagnostic limitations. By varying MAP diode operating parameters, ion beams can be extracted at a few 10s of keV or at up to 150keV, the corresponding accelerating gap impedance ranging from about 1Ω to about 10Ω. The ability to make hundreds of test pulses per day at an average repetition rate of about 2 pulses per minute permits statistical analysis of diode operation as a function of various parameters. Most diode components have now survived more than 10 4 pulses, and the design and construction of the various pulsed power components of the MAP diode which have enabled us to reach this point are discussed. A high speed data acquisition system and companion analysis software capable of acquiring pulse data at 1ms intervals (in bursts of up to 10 pulses) and processing it in ≤ min is described

  3. High strain rate deformation of layered nanocomposites.

    Science.gov (United States)

    Lee, Jae-Hwang; Veysset, David; Singer, Jonathan P; Retsch, Markus; Saini, Gagan; Pezeril, Thomas; Nelson, Keith A; Thomas, Edwin L

    2012-01-01

    Insight into the mechanical behaviour of nanomaterials under the extreme condition of very high deformation rates and to very large strains is needed to provide improved understanding for the development of new protective materials. Applications include protection against bullets for body armour, micrometeorites for satellites, and high-speed particle impact for jet engine turbine blades. Here we use a microscopic ballistic test to report the responses of periodic glassy-rubbery layered block-copolymer nanostructures to impact from hypervelocity micron-sized silica spheres. Entire deformation fields are experimentally visualized at an exceptionally high resolution (below 10 nm) and we discover how the microstructure dissipates the impact energy via layer kinking, layer compression, extreme chain conformational flattening, domain fragmentation and segmental mixing to form a liquid phase. Orientation-dependent experiments show that the dissipation can be enhanced by 30% by proper orientation of the layers.

  4. High strain rate deformation of layered nanocomposites

    Science.gov (United States)

    Lee, Jae-Hwang; Veysset, David; Singer, Jonathan P.; Retsch, Markus; Saini, Gagan; Pezeril, Thomas; Nelson, Keith A.; Thomas, Edwin L.

    2012-11-01

    Insight into the mechanical behaviour of nanomaterials under the extreme condition of very high deformation rates and to very large strains is needed to provide improved understanding for the development of new protective materials. Applications include protection against bullets for body armour, micrometeorites for satellites, and high-speed particle impact for jet engine turbine blades. Here we use a microscopic ballistic test to report the responses of periodic glassy-rubbery layered block-copolymer nanostructures to impact from hypervelocity micron-sized silica spheres. Entire deformation fields are experimentally visualized at an exceptionally high resolution (below 10 nm) and we discover how the microstructure dissipates the impact energy via layer kinking, layer compression, extreme chain conformational flattening, domain fragmentation and segmental mixing to form a liquid phase. Orientation-dependent experiments show that the dissipation can be enhanced by 30% by proper orientation of the layers.

  5. High-frame-rate digital radiographic videography

    Science.gov (United States)

    King, Nicholas S. P.; Cverna, Frank H.; Albright, Kevin L.; Jaramillo, Steven A.; Yates, George J.; McDonald, Thomas E.; Flynn, Michael J.; Tashman, Scott

    1994-10-01

    High speed x-ray imaging can be an important tool for observing internal processes in a wide range of applications. In this paper we describe preliminary implementation of a system having the eventual goal of observing the internal dynamics of bone and joint reactions during loading. Two Los Alamos National Laboratory (LANL) gated and image intensified camera systems were used to record images from an x-ray image convertor tube to demonstrate the potential of high frame-rate digital radiographic videography in the analysis of bone and joint dynamics of the human body. Preliminary experiments were done at LANL to test the systems. Initial high frame-rate imaging (from 500 to 1000 frames/s) of a swinging pendulum mounted to the face of an X-ray image convertor tube demonstrated high contrast response and baseline sensitivity. The systems were then evaluated at the Motion Analysis Laboratory of Henry Ford Health Systems Bone and Joint Center. Imaging of a 9 inch acrylic disk with embedded lead markers rotating at approximately 1000 RPM, demonstrated the system response to a high velocity/high contrast target. By gating the P-20 phosphor image from the X-ray image convertor with a second image intensifier (II) and using a 100 microsecond wide optical gate through the second II, enough prompt light decay from the x-ray image convertor phosphor had taken place to achieve reduction of most of the motion blurring. Measurement of the marker velocity was made by using video frames acquired at 500 frames/s. The data obtained from both experiments successfully demonstrated the feasibility of the technique. Several key areas for improvement are discussed along with salient test results and experiment details.

  6. High counting rate resistive-plate chamber

    International Nuclear Information System (INIS)

    Peskov, V.; Anderson, D.F.; Kwan, S.

    1993-05-01

    Parallel-plate avalanche chambers (PPAC) are widely used in physics experiments because they are fast ( 5 counts/mm 2 . A resistive-plate chamber (RPC) is similar to the PPAC in construction except that one or both of the electrodes are made from high resistivity (≥10 10 Ω·cm) materials. In practice RPCs are usually used in the spark mode. Resistive electrodes are charged by sparks, locally reducing the actual electric field in the gap. The size of the charged surface is about 10 mm 2 , leaving the rest of the detector unaffected. Therefore, the rate capability of such detectors in the spark mode is considerably higher than conventional spark counters. Among the different glasses tested the best results were obtained with electron type conductive glasses, which obey Ohm's law. Most of the work with such glasses was done with high pressure parallel-plate chambers (10 atm) for time-of-flight measurements. Resistive glasses have been expensive and produced only in small quantities. Now resistive glasses are commercially available, although they are still expensive in small scale production. From the positive experience of different groups working with the resistive glasses, it was decided to review the old idea to use this glass for the RPC. This work has investigated the possibility of using the RPC at 1 atm and in the avalanche mode. This has several advantages: simplicity of construction, high rate capability, low voltage operation, and the ability to work with non-flammable gases

  7. Emotional variables, dropout and academic performance in Spanish nursing students.

    Science.gov (United States)

    Roso-Bas, Fátima; Pades Jiménez, Antonia; García-Buades, Esther

    2016-02-01

    The dropout of university studies is a main concern in many countries, also for Health Sciences degrees. The reviews on dropout in all university degrees as well as nursing generally show multidimensional causes with factors related both to institutional and students' characteristics. Regarding the personal variables of students, researchers have focused on financial, family and personality features. Far less attention has been devoted to emotional variables. This study aims to explore whether individual variables of the emotional domain such as perceived emotional intelligence, dispositional optimism/pessimism and depressive rumination are related and/or can predict students' intention to dropout and academic performance. Using a cross-correlational approach, data were obtained from a sample of 144 nursing students. Students with a pessimistic disposition revealed a greater tendency to drop out. The remaining variables correlated significantly with pessimism but had no predictive value on dropout. Our results suggest that students with low levels of emotional clarity and repair and high depressive rumination have pessimistic expectations, so they are more likely to leave studies. No significant results were found in relation to academic performance. We conclude with an identification of strategies to increase retention and academic success. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. The Societal Benefits and Costs of School Dropout Recovery

    Directory of Open Access Journals (Sweden)

    James S. Catterall

    2011-01-01

    Full Text Available This article reports an analysis of the societal benefits and costs of recovering school dropouts. Successful recovery is defined by subsequent graduation from high school. The analysis is based on established estimates of the societal costs of dropping out including reduced government tax collections and higher social costs of welfare, healthcare, and crime. These potential costs are cast as benefits when a dropout is recovered. A large dropout recovery program provides the setting for the analysis. Rigorous attention is given to accurate estimation of the number of students who would not have graduated without the program in the year assessed and to the induced public costs of their continued education. Estimated benefits are weighed against the total annual public costs of the program, which operates in 65 school centers and commands an annual budget of about $70 million. The estimated benefit-cost ratio for this program is 3 to 1, a figure comparable to benefit-cost ratio estimates reported in studies of dropout prevention. The sensitivity of this conclusion to specific assumptions within the analysis is discussed.

  9. On high interest rates in Brazil

    Directory of Open Access Journals (Sweden)

    Francisco Lafaiete Lopes

    2014-03-01

    Full Text Available This article examines the question of why interest rates are so high in Brazil as compared to the international average. It looks at theoretical arguments based on excessive government deficits, structural lack of private savings, inflation bias, excessive investment demand and fear of floating. An informal look at the evidence does not strongly corroborate any of these arguments. Hence a wise central bank should consider "testing" the market to make sure it is not dealing with an extreme equilibrium configuration or a long standing disequilibrium.

  10. Flashing motor at high transition rate

    International Nuclear Information System (INIS)

    Ai Baoquan; Wang Liqiu; Liu Lianggang

    2007-01-01

    The movement of a Brownian particle in a fluctuating two-state periodic potential is investigated. At high transition rate, we use a perturbation method to obtain the analytical solution of the model. It is found that the net current is a peaked function of thermal noise, barrier height and the fluctuation ratio between the two states. The thermal noise may facilitate the directed motion at a finite intensity. The asymmetry parameter of the potential is sensitive to the direction of the net current

  11. Predicting secondary school dropout among South African ...

    African Journals Online (AJOL)

    ... not living with one's mother, smoking cigarettes in the past month, and lower levels of leisure-related intrinsic motivation significantly predicted dropout. Results support comprehensive prevention programmes that target risk behaviour and leisure. Keywords: adolescence; leisure motivation; school dropout; substance use ...

  12. West Virginia Dropout Study, 1985-86.

    Science.gov (United States)

    West Virginia State Dept. of Education, Charleston. Div. of General and Special Educational Development.

    Reported in this document are dropout statistics from the State of West Virginia for the school year 1985-86. This annual survey of the 55 county school systems has been conducted since the 1968-69 school year. Topics surveyed include Education Consolidation and Improvement Act (ECIA) status, exit interviews, grade at exit, month dropout left…

  13. Parents and the School Dropout Problem.

    Science.gov (United States)

    Ferguson, Earl E.; Killingsworth, Jerry

    1987-01-01

    The school dropout problem is discussed, with suggestions for parents on ensuring that their children do not become part of the dropout population, including; monitoring children's school attendance patterns; making sure children understand how important school and attendance is; maintaining close contact with teachers; and helping children…

  14. Valued Youth Anthology: Articles on Dropout Prevention.

    Science.gov (United States)

    Intercultural Development Research Association, San Antonio, TX.

    This document contains, in chronological order, all articles related to dropouts that have appeared in the Intercultural Development Research Association (IDRA) Newsletter from 1986 to 1989. The articles are: (1) "The Prevention and Recovery of Dropouts: An Action Agenda" (Robledo); (2) "Coca Cola Valued Youth Partnership Program Results of Second…

  15. Revisiting Primary School Dropout in Rural Cambodia

    Science.gov (United States)

    No, Fata; Sam, Chanphirun; Hirakawa, Yukiko

    2012-01-01

    Previous studies on school dropout in Cambodia often used data from subjects after they already dropped out or statistics from education-related institutions. Using data from children in two rural provinces before they dropped out, this study examines four main factors in order to identify their influence on primary school dropout in Cambodia.…

  16. Child Psychotherapy Dropout: An Empirical Research Review

    Science.gov (United States)

    Deakin, Elisabeth; Gastaud, Marina; Nunes, Maria Lucia Tiellet

    2012-01-01

    This study aims to discuss the most recent data about child psychotherapy dropout, especially child psychoanalytical psychotherapy. The authors also try to offer some possible alternatives to prevent such a phenomenon. The definition of "child psychotherapy dropout" is extensively discussed. The goal has been to attempt to create a standardised…

  17. High dose rate brachytherapy for oral cancer

    International Nuclear Information System (INIS)

    Yamazaki, Hideya; Yoshida, Ken; Yoshioka, Yasuo; Shimizutani, Kimishige; Koizumi, Masahiko; Ogawa, Kazuhiko; Furukawa, Souhei

    2013-01-01

    Brachytherapy results in better dose distribution compared with other treatments because of steep dose reduction in the surrounding normal tissues. Excellent local control rates and acceptable side effects have been demonstrated with brachytherapy as a sole treatment modality, a postoperative method, and a method of reirradiation. Low-dose-rate (LDR) brachytherapy has been employed worldwide for its superior outcome. With the advent of technology, high-dose-rate (HDR) brachytherapy has enabled health care providers to avoid radiation exposure. This therapy has been used for treating many types of cancer such as gynecological cancer, breast cancer, and prostate cancer. However, LDR and pulsed-dose-rate interstitial brachytherapies have been mainstays for head and neck cancer. HDR brachytherapy has not become widely used in the radiotherapy community for treating head and neck cancer because of lack of experience and biological concerns. On the other hand, because HDR brachytherapy is less time-consuming, treatment can occasionally be administered on an outpatient basis. For the convenience and safety of patients and medical staff, HDR brachytherapy should be explored. To enhance the role of this therapy in treatment of head and neck lesions, we have reviewed its outcomes with oral cancer, including Phase I/II to Phase III studies, evaluating this technique in terms of safety and efficacy. In particular, our studies have shown that superficial tumors can be treated using a non-invasive mold technique on an outpatient basis without adverse reactions. The next generation of image-guided brachytherapy using HDR has been discussed. In conclusion, although concrete evidence is yet to be produced with a sophisticated study in a reproducible manner, HDR brachytherapy remains an important option for treatment of oral cancer. (author)

  18. High dose rate brachytherapy for oral cancer.

    Science.gov (United States)

    Yamazaki, Hideya; Yoshida, Ken; Yoshioka, Yasuo; Shimizutani, Kimishige; Furukawa, Souhei; Koizumi, Masahiko; Ogawa, Kazuhiko

    2013-01-01

    Brachytherapy results in better dose distribution compared with other treatments because of steep dose reduction in the surrounding normal tissues. Excellent local control rates and acceptable side effects have been demonstrated with brachytherapy as a sole treatment modality, a postoperative method, and a method of reirradiation. Low-dose-rate (LDR) brachytherapy has been employed worldwide for its superior outcome. With the advent of technology, high-dose-rate (HDR) brachytherapy has enabled health care providers to avoid radiation exposure. This therapy has been used for treating many types of cancer such as gynecological cancer, breast cancer, and prostate cancer. However, LDR and pulsed-dose-rate interstitial brachytherapies have been mainstays for head and neck cancer. HDR brachytherapy has not become widely used in the radiotherapy community for treating head and neck cancer because of lack of experience and biological concerns. On the other hand, because HDR brachytherapy is less time-consuming, treatment can occasionally be administered on an outpatient basis. For the convenience and safety of patients and medical staff, HDR brachytherapy should be explored. To enhance the role of this therapy in treatment of head and neck lesions, we have reviewed its outcomes with oral cancer, including Phase I/II to Phase III studies, evaluating this technique in terms of safety and efficacy. In particular, our studies have shown that superficial tumors can be treated using a non-invasive mold technique on an outpatient basis without adverse reactions. The next generation of image-guided brachytherapy using HDR has been discussed. In conclusion, although concrete evidence is yet to be produced with a sophisticated study in a reproducible manner, HDR brachytherapy remains an important option for treatment of oral cancer.

  19. Predictors of dropout from inpatient dialectical behavior therapy among women with borderline personality disorder.

    Science.gov (United States)

    Rüsch, Nicolas; Schiel, Sarah; Corrigan, Patrick W; Leihener, Florian; Jacob, Gitta A; Olschewski, Manfred; Lieb, Klaus; Bohus, Martin

    2008-12-01

    Inpatient dialectical behavior therapy (DBT) is an effective treatment for borderline personality disorder (BPD), but often treatment is ended prematurely and predictors of dropout are poorly understood. We, therefore, studied predictors of dropout among 60 women with BPD during inpatient DBT. Non-completers had higher experiential avoidance and trait anxiety at baseline, but fewer life-time suicide attempts than completers. There was a trend for more anger-hostility and perceived stigma among non-completers. Experiential avoidance and anxiety may be associated with dropout in inpatient DBT. Low life-time suicidality and high anger could reflect a subtype at risk for discontinuation of inpatient treatment.

  20. Ultra Fast, High Rep Rate, High Voltage Spark Gap Pulser

    Science.gov (United States)

    1995-07-01

    current rise time. The spark gap was designed to have a coaxial geometry reducing its inductance. Provisions were made to pass flowing gas between the...ULTRA FAST, HIGH REP RATE, HIGH VOLTAGE SPARK GAP PULSER Robert A. Pastore Jr., Lawrence E. Kingsley, Kevin Fonda, Erik Lenzing Electrophysics and...Modeling Branch AMSRL-PS-EA Tel.: (908)-532-0271 FAX: (908)-542-3348 U.S. Army Research Laboratory Physical Sciences Directorate Ft. Monmouth

  1. [ANALYSIS OF BACKGROUNDS AND LEVEL OF UNDERSTANDING OF TREATMENT OF POOR ADHERENCE AND DROPOUT CASES ON SUBLINGUAL IMMUNOTHERAPY FOR JAPANESE CEDAR POLLINOSIS IN THE FIRST FOLLOW-UP YEAR].

    Science.gov (United States)

    Kikkawa, Sayaka; Kamijo, Atsushi; Nakagome, Kazuyuki; Soma, Tomoyuki; Kobayashi, Takehito; Uchida, Yoshitaka; Morita, Eiji; Nagata, Makoto; Inoue, Tomoe; Kase, Yasuhiro

    We considered the factors of poor adherence to and dropout from sublingual immunotherapy (SLIT) by verifying patient backgrounds 1 year after start of treatment. We recruited 38 patients who began SLIT between November 2014 and September 2015. We analyzed their attributes and level of understanding of the treatment, and conducted a self-reported survey on factors behind dropout cases and poor adherence cases. Four patients dropped out 1 year after start of treatment. Three left for reasons related to anxiety about side effects. There were five cases of poor adherence. There was no significant difference between good adherence, poor adherence, and dropout regarding level of understanding of the treatment (p=0.59). In the comparison between good and poor adherence groups, except four dropout patients, the adherence tended to be poor in patients with short duration of disease, smoking patients, and young patients. Continuous rate of SLIT achieved about 90%, suggesting relatively high level of adherence. It appears possible that anxiety related to side effects could be a factor affecting dropout from SLIT. There was no significant difference regarding level of understanding of the treatment. The adherence tended to be poor in patients with short duration of disease, smoking patients, and young patients.

  2. Operation of high rate microstrip gas chambers

    CERN Document Server

    Barr, A J; Bouclier, Roger; Capéans-Garrido, M; Dominik, Wojciech; Manzin, G; Million, Gilbert; Hoch, M; Ropelewski, Leszek; Sauli, Fabio; Sharma, A

    1996-01-01

    We describe recent measurements carried out in well controlled and reproducible conditions to help understanding the factors affecting the short and long term behaviour of Microstrip Gas Chambers. Special care has been taken concerning the gas purity and choice of materials used in the system and for the detectors construction. Detectors built on glasses with surface resistivity in the range $10^{13}-10^{15} \\Omega/\\Box$ have shown satisfactory performance as they do not show charging-up process at high rate and stand the large doses required for the future high luminosity experiments (~10 mC·cm-1·yr-1). Concerning the lifetime measurements, it has been observed that chambers manufactured on high-resistivity glass are far more susceptible of suffering ageing than detectors made on low resistivity, electron-conducting supports, independently of the metal used for the artwork (chromium or gold) at least in clean gas conditions. The successfully operation in the laboratory of detectors manufactured on diamond-...

  3. Comparisons of High School Graduation Rates of Students with Disabilities and Their Peers in Twelve Southern States

    Science.gov (United States)

    Smith, Theodore Scott; Manuel, Nancy; Stokes, Billy R.

    2012-01-01

    This study compared differences in diploma and graduation dropout rates among students with and without disabilities, analyzed differences in various graduation-types by disabilities, and offered recommendations to improve graduation rates through evidence-based practices. The geographic catchment area of this study was limited to twelve Southern…

  4. A Systematic Review of Dropout From Psychotherapy for Posttraumatic Stress Disorder Among Iraq and Afghanistan Combat Veterans.

    Science.gov (United States)

    Goetter, Elizabeth M; Bui, Eric; Ojserkis, Rebecca A; Zakarian, Rebecca J; Brendel, Rebecca Weintraub; Simon, Naomi M

    2015-10-01

    A significant number of veterans of the conflicts in Iraq and Afghanistan have posttraumatic stress disorder (PTSD), yet underutilization of mental health treatment remains a significant problem. The purpose of this review was to summarize rates of dropout from outpatient, psychosocial PTSD interventions provided to U.S. Operation Iraqi Freedom (OIF), Operation Enduring Freedom (OEF), and Operation New Dawn (OND) veterans with combat-related PTSD. There were 788 articles that were identified which yielded 20 studies involving 1,191 individuals eligible for the review. The dropout rates in individual studies ranged from 5.0% to 78.2%, and the overall pooled dropout rate was 36%, 95% CI [26.20, 43.90]. The dropout rate differed marginally by study type (routine clinical care settings had higher dropout rates than clinical trials) and treatment format (group treatment had higher dropout rates than individual treatment), but not by whether comorbid substance dependence was excluded, by treatment modality (telemedicine vs. in-person treatment), or treatment type (exposure therapy vs. nonexposure therapy). Dropout is a critical aspect of the problem of underutilization of care among OEF/OIF/OND veterans with combat-related PTSD. Innovative strategies to enhance treatment retention are needed. Copyright © 2015 Wiley Periodicals, Inc., A Wiley Company.

  5. Consideration of wear rates at high velocity

    Science.gov (United States)

    Hale, Chad S.

    The development of the research presented here is one in which high velocity relative sliding motion between two bodies in contact has been considered. Overall, the wear environment is truly three-dimensional. The attempt to characterize three-dimensional wear was not economically feasible because it must be analyzed at the micro-mechanical level to get results. Thus, an engineering approximation was carried out. This approximation was based on a metallographic study identifying the need to include viscoplasticity constitutive material models, coefficient of friction, relationships between the normal load and velocity, and the need to understand wave propagation. A sled test run at the Holloman High Speed Test Track (HHSTT) was considered for the determination of high velocity wear rates. In order to adequately characterize high velocity wear, it was necessary to formulate a numerical model that contained all of the physical events present. The experimental results of a VascoMax 300 maraging steel slipper sliding on an AISI 1080 steel rail during a January 2008 sled test mission were analyzed. During this rocket sled test, the slipper traveled 5,816 meters in 8.14 seconds and reached a maximum velocity of 1,530 m/s. This type of environment was never considered previously in terms of wear evaluation. Each of the features of the metallography were obtained through micro-mechanical experimental techniques. The byproduct of this analysis is that it is now possible to formulate a model that contains viscoplasticity, asperity collisions, temperature and frictional features. Based on the observations of the metallographic analysis, these necessary features have been included in the numerical model, which makes use of a time-dynamic program which follows the movement of a slipper during its experimental test run. The resulting velocity and pressure functions of time have been implemented in the explicit finite element code, ABAQUS. Two-dimensional, plane strain models

  6. Student dropout in primary and secondary education in the Republic of Serbia

    Directory of Open Access Journals (Sweden)

    Krstić Ksenija

    2017-01-01

    Full Text Available Student dropout from school is a serious problem in educational systems all over the world. This paper will provide an overview of the various dropout definitions and their consequences for measuring and monitoring. Since a diversity of factors (individual, familial, school and systematic is connected with student attrition in foreign research, the attempt has been made to systematise their results and provide data regarding similar Serbian studies. Considering the fact that there are no systematic analyses of students’ dropout rate in Serbia, the existing data from primary and secondary schools from a variety of statistical sources will be presented. We conclude that one way to reduce dropout in Serbia is to further develop research interest in the topic, as well as the strategies for monitoring, prevention and intervention.

  7. High Data Rate Architecture (HiDRA)

    Science.gov (United States)

    Hylton, Alan; Raible, Daniel

    2016-01-01

    high-rate laser terminals. These must interface with the existing, aging data infrastructure. The High Data Rate Architecture (HiDRA) project is designed to provide networked store, carry, and forward capability to optimize data flow through both the existing radio frequency (RF) and new laser communications terminal. The networking capability is realized through the Delay Tolerant Networking (DTN) protocol, and is used for scheduling data movement as well as optimizing the performance of existing RF channels. HiDRA is realized as a distributed FPGA memory and interface controller that is itself controlled by a local computer running DTN software. Thus HiDRA is applicable to other arenas seeking to employ next-generation communications technologies, e.g. deep space. In this paper, we describe HiDRA and its far-reaching research implications.

  8. Photocathodes for High Repetition Rate Light Sources

    Energy Technology Data Exchange (ETDEWEB)

    Ben-Zvi, Ilan [Stony Brook Univ., NY (United States). Dept. of Physics and Astronomy. Center for Accelerator Science and Education

    2014-04-20

    This proposal brought together teams at Brookhaven National Laboratory (BNL), Lawrence Berkeley National Laboratory (LBNL) and Stony Brook University (SBU) to study photocathodes for high repetition rate light sources such as Free Electron Lasers (FEL) and Energy Recovery Linacs (ERL). Below details the Principal Investigators and contact information. Each PI submits separately for a budget through his corresponding institute. The work done under this grant comprises a comprehensive program on critical aspects of the production of the electron beams needed for future user facilities. Our program pioneered in situ and in operando diagnostics for alkali antimonide growth. The focus is on development of photocathodes for high repetition rate Free Electron Lasers (FELs) and Energy Recovery Linacs (ERLs), including testing SRF photoguns, both normal-­conducting and superconducting. Teams from BNL, LBNL and Stony Brook University (SBU) led this research, and coordinated their work over a range of topics. The work leveraged a robust infrastructure of existing facilities and the support was used for carrying out the research at these facilities. The program concentrated in three areas: a) Physics and chemistry of alkali-­antimonide cathodes (BNL – LBNL) b) Development and testing of a diamond amplifier for photocathodes (SBU -­ BNL) c) Tests of both cathodes in superconducting RF photoguns (SBU) and copper RF photoguns (LBNL) Our work made extensive use of synchrotron radiation materials science techniques, such as powder-­ and single-­crystal diffraction, x-­ray fluorescence, EXAFS and variable energy XPS. BNL and LBNL have many complementary facilities at the two light sources associated with these laboratories (NSLS and ALS, respectively); use of these will be a major thrust of our program and bring our understanding of these complex materials to a new level. In addition, CHESS at Cornell will be used to continue seamlessly throughout the NSLS dark period and

  9. Childhood Trauma and Psychiatric Disorders as Correlates of School Dropout in a National Sample of Young Adults

    Science.gov (United States)

    Porche, Michelle V.; Fortuna, Lisa R.; Lin, Julia; Alegria, Margarita

    2010-01-01

    The effect of childhood trauma, psychiatric diagnoses, and mental health services on school dropout among U.S. born and immigrant youth is examined using data from the Collaborative Psychiatric Epidemiology Surveys (CPES), a nationally representative probability sample of African Americans, Afro-Caribbeans, Asians, Latinos, and non-Latino Whites, including 2532 young adults, ages 21 to 29. The dropout prevalence rate was 16% overall, with variation by childhood trauma, childhood psychiatric diagnosis, race/ethnicity, and nativity. Childhood substance and conduct disorders mediated the relationship between trauma and school dropout. Likelihood of dropout was decreased for Asians, and increased for African Americans and Latinos, compared to non-Latino Whites as a function of psychiatric disorders and trauma. Timing of U.S. immigration during adolescence increased risk of dropout. PMID:21410919

  10. Examining the Factors Affecting Student Dropout

    Directory of Open Access Journals (Sweden)

    Fethi Ahmet INAN

    2006-07-01

    Full Text Available This study examined the factors affecting student dropouts in an online certificate program. In this research, a combination of quantitative and qualitative methods was used. Online Course Dropout Survey was developed and used to determine which factors affect student attrition from the program. The dropout survey was sent by e-mail to 98 students who had dropped the program. Twenty-six students returned the survey. The findings show that the most important factor affecting student retention is finding sufficient time to study. Having personal problems and affordability of the program took second and third place.

  11. Treatment of the Aged Patients at a Large Cardiac Rehabilitation Center in the Southern Brazil and Some Aspects of Their Dropout from the Therapeutic Programs.

    Science.gov (United States)

    Nesello, Pietro Felice Tomazini; Tairova, Olga; Tairova, Maria; Graciolli, Lucas; Baroni, Allan; Comparsi, Eduardo; Marchi, Thiago De

    2016-12-15

    This paper aims to assess the dropout rate in different age groups through the example of the large cardiac rehabilitation centre affiliated with the Institute of Sports Medicine, University of Caxias do Sul. A historic cohort study comprising the following groups: Non-Old dropout was defined as attendance of 50% of sessions or less. Logistic binominal regression was performed to assess the risk of dropout. For all analyses, a two-tailed P value of dropout rate was 38.6%. The Young-Old and Middle-Old groups showed lower dropouts compared to Non-Old patients (p = 0.01). Young-Old has 96% less risk for dropout compared to Non-Old group (adjusted odds ratios = 1.96 [1.16-3.29]). Furthermore, patients underwent the Coronary Artery Bypass Graft showed a lower rate of dropout (p = 0.001). The absence of CABG involved three times more risk of dropout (p = 0.001). The Non-Old and the Middle-Old patients showed higher dropout rates compared to Young-Old. To ensure the best possible rehabilitation and to improve patients´ participation in CR, these programs should be adjusted to the needs of patients in terms of their age.

  12. Overdensities of Y-dropout Galaxies from the Brightest-of-Reionizing Galaxies Survey: A Candidate Protocluster at Redshift z ≈ 8

    Science.gov (United States)

    Trenti, Michele; Bradley, L. D.; Stiavelli, M.; Shull, J. M.; Oesch, P.; Bouwens, R. J.; Muñoz, J. A.; Romano-Diaz, E.; Treu, T.; Shlosman, I.; Carollo, C. M.

    2012-02-01

    Theoretical and numerical modeling of the assembly of dark-matter halos predicts that the most massive and luminous galaxies at high redshift are surrounded by overdensities of fainter companions. We test this prediction with Hubble Space Telescope observations acquired by our Brightest-of-Reionizing Galaxies (BoRG) survey, which identified four very bright z ~ 8 candidates as Y 098-dropout sources in four of the 23 non-contiguous Wide Field Camera 3 fields observed. We extend here the search for Y 098-dropouts to fainter luminosities (M * galaxies with M AB ~ -20), with detections at >=5σ confidence (compared to the 8σ confidence threshold adopted earlier) identifying 17 new candidates. We demonstrate that there is a correlation between number counts of faint and bright Y 098-dropouts at >=99.84% confidence. Field BoRG58, which contains the best bright z ~ 8 candidate (M AB = -21.3), has the most significant overdensity of faint Y 098-dropouts. Four new sources are located within 70'' (corresponding to 3.1 comoving Mpc at z = 8) from the previously known brighter z ~ 8 candidate. The overdensity of Y 098-dropouts in this field has a physical origin to very high confidence (p > 99.975%), independent of completeness and contamination rate of the Y 098-dropout selection. We modeled the overdensity by means of cosmological simulations and estimate that the principal dark-matter halo has mass Mh ≈ (4-7) × 1011 M ⊙ (~5σ density peak) and is surrounded by several Mh ≈ 1011 M ⊙ halos which could host the fainter dropouts. In this scenario, we predict that all halos will eventually merge into a Mh > 2 × 1014 M ⊙ galaxy cluster by z = 0. Follow-up observations with ground- and space-based telescopes are required to secure the z ~ 8 nature of the overdensity, discover new members, and measure their precise redshift. Based on observations made with the NASA/ESA Hubble Space Telescope, which is operated by the Association of Universities for Research in

  13. OVERDENSITIES OF Y-DROPOUT GALAXIES FROM THE BRIGHTEST-OF-REIONIZING GALAXIES SURVEY: A CANDIDATE PROTOCLUSTER AT REDSHIFT z Almost-Equal-To 8

    Energy Technology Data Exchange (ETDEWEB)

    Trenti, Michele; Shull, J. M. [CASA, Department of Astrophysical and Planetary Science, University of Colorado, Center for Astrophysics and Space Astronomy, 389-UCB, Boulder, CO 80309 (United States); Bradley, L. D.; Stiavelli, M. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Oesch, P.; Bouwens, R. J. [Astronomy and Astrophysics Department, University of California, Santa Cruz, CA 95064 (United States); Munoz, J. A. [Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, CA 90095 (United States); Romano-Diaz, E.; Shlosman, I. [Department of Physics and Astronomy, University of Kentucky, Lexington, KY 40506-0055 (United States); Treu, T. [Department of Physics, University of California, Santa Barbara, CA 93106-9530 (United States); Carollo, C. M., E-mail: trenti@colorado.edu [Institute of Astronomy, ETH Zurich, CH-8093 Zurich (Switzerland)

    2012-02-10

    Theoretical and numerical modeling of the assembly of dark-matter halos predicts that the most massive and luminous galaxies at high redshift are surrounded by overdensities of fainter companions. We test this prediction with Hubble Space Telescope observations acquired by our Brightest-of-Reionizing Galaxies (BoRG) survey, which identified four very bright z {approx} 8 candidates as Y{sub 098}-dropout sources in four of the 23 non-contiguous Wide Field Camera 3 fields observed. We extend here the search for Y{sub 098}-dropouts to fainter luminosities (M{sub *} galaxies with M{sub AB} {approx} -20), with detections at {>=}5{sigma} confidence (compared to the 8{sigma} confidence threshold adopted earlier) identifying 17 new candidates. We demonstrate that there is a correlation between number counts of faint and bright Y{sub 098}-dropouts at {>=}99.84% confidence. Field BoRG58, which contains the best bright z {approx} 8 candidate (M{sub AB} = -21.3), has the most significant overdensity of faint Y{sub 098}-dropouts. Four new sources are located within 70'' (corresponding to 3.1 comoving Mpc at z = 8) from the previously known brighter z {approx} 8 candidate. The overdensity of Y{sub 098}-dropouts in this field has a physical origin to very high confidence (p > 99.975%), independent of completeness and contamination rate of the Y{sub 098}-dropout selection. We modeled the overdensity by means of cosmological simulations and estimate that the principal dark-matter halo has mass M{sub h} Almost-Equal-To (4-7) Multiplication-Sign 10{sup 11} M{sub Sun} ({approx}5{sigma} density peak) and is surrounded by several M{sub h} Almost-Equal-To 10{sup 11} M{sub Sun} halos which could host the fainter dropouts. In this scenario, we predict that all halos will eventually merge into a M{sub h} > 2 Multiplication-Sign 10{sup 14} M{sub Sun} galaxy cluster by z = 0. Follow-up observations with ground- and space-based telescopes are required to secure the z {approx} 8 nature

  14. OVERDENSITIES OF Y-DROPOUT GALAXIES FROM THE BRIGHTEST-OF-REIONIZING GALAXIES SURVEY: A CANDIDATE PROTOCLUSTER AT REDSHIFT z ≈ 8

    International Nuclear Information System (INIS)

    Trenti, Michele; Shull, J. M.; Bradley, L. D.; Stiavelli, M.; Oesch, P.; Bouwens, R. J.; Muñoz, J. A.; Romano-Diaz, E.; Shlosman, I.; Treu, T.; Carollo, C. M.

    2012-01-01

    Theoretical and numerical modeling of the assembly of dark-matter halos predicts that the most massive and luminous galaxies at high redshift are surrounded by overdensities of fainter companions. We test this prediction with Hubble Space Telescope observations acquired by our Brightest-of-Reionizing Galaxies (BoRG) survey, which identified four very bright z ∼ 8 candidates as Y 098 -dropout sources in four of the 23 non-contiguous Wide Field Camera 3 fields observed. We extend here the search for Y 098 -dropouts to fainter luminosities (M * galaxies with M AB ∼ –20), with detections at ≥5σ confidence (compared to the 8σ confidence threshold adopted earlier) identifying 17 new candidates. We demonstrate that there is a correlation between number counts of faint and bright Y 098 -dropouts at ≥99.84% confidence. Field BoRG58, which contains the best bright z ∼ 8 candidate (M AB = –21.3), has the most significant overdensity of faint Y 098 -dropouts. Four new sources are located within 70'' (corresponding to 3.1 comoving Mpc at z = 8) from the previously known brighter z ∼ 8 candidate. The overdensity of Y 098 -dropouts in this field has a physical origin to very high confidence (p > 99.975%), independent of completeness and contamination rate of the Y 098 -dropout selection. We modeled the overdensity by means of cosmological simulations and estimate that the principal dark-matter halo has mass M h ≈ (4-7) × 10 11 M ☉ (∼5σ density peak) and is surrounded by several M h ≈ 10 11 M ☉ halos which could host the fainter dropouts. In this scenario, we predict that all halos will eventually merge into a M h > 2 × 10 14 M ☉ galaxy cluster by z = 0. Follow-up observations with ground- and space-based telescopes are required to secure the z ∼ 8 nature of the overdensity, discover new members, and measure their precise redshift.

  15. Brachytherapy treatment with high dose rate

    International Nuclear Information System (INIS)

    Santana Rodriguez, Sergio Marcelino; Rodriguez Rodriguez, Lissi Lisbet; Ciscal Chiclana, Onelio Alberto

    2009-01-01

    Retrospectively analyze results and prognostic factors of cervical cancer patients treated with radio concomitant cisplatin-based chemotherapy, radiation therapy combined modality. Methods: From January 2003 to December 2007, 198 patients with invasive cervical cancer were treated at the Oncology Department of Hospital Robau Celestino Hernandez (brachytherapy performed at INOR). The most common age group was 31 to 40 years. The histology in squamous cell carcinoma accounted for 84.3% of cases. The treatment consisted of external pelvic irradiation and vaginal brachytherapy, high dose rate. Concomitant chemotherapy consisted of cisplatin 40 mg/m2 weekly with a maximum of 70 mg for 5 weeks. Results: 66.2% of patients completed 5 cycles of chemotherapy. The median overall survival was 39 months, overall survival, disease-free survival and survival free of locoregional recurrence at 5 years of 78%, 76% and 78.6% respectively .. We found that clinical stage, histological type (adenocarcinoma worst outcome) were statistically related to level of response. Conclusions: Treatment with external pelvic radiation, brachytherapy and concurrent weekly cisplatin in patients with stage IIIB cervical cancer is feasible in the Chilean public health system, well tolerated and results comparable to international literature. (Author)

  16. Is obesity associated with school dropout? Key developmental and ethnic differences

    Science.gov (United States)

    Lanza, H. Isabella; Huang, David Y.C.

    2015-01-01

    Background We aimed to expand the literature on child obesity and school outcomes by examining associations between obesity and high school dropout, including the role of obesity onset and duration as well as ethnicity. Methods Data on 5066 children obtained between 1986 and 2010 from the child cohort of the 1979 National Longitudinal Study of Youth (NLSY79) were analyzed. Group-based trajectory analysis identified obesity trajectories from 6-18 years. School completion information from age 14 into young adulthood was used to calculate school dropout. Chi-square and pairwise comparison tests were used to identify significant associations between obesity trajectories and school dropout. Results Adolescents belonging to an increasing trajectory (adolescent-onset obesity) had a higher likelihood of dropping out of high school compared to those belonging to chronic, decreasing (childhood-only obesity), and non-obese trajectories. This association was particularly salient among white adolescents. Conclusions Obesity onset during early adolescence increased risk of high school dropout. White adolescents were particularly vulnerable. Given that early adolescence is marked by significant biological and social changes, future research should seek to identify the underlying processes linking adolescent-obesity and school dropout to decrease school dropout risk among this vulnerable population. PMID:26331748

  17. STATISTIC MODEL OF DYNAMIC DELAY AND DROPOUT ON CELLULAR DATA NETWORKED CONTROL SYSTEM

    Directory of Open Access Journals (Sweden)

    MUHAMMAD A. MURTI

    2017-07-01

    Full Text Available Delay and dropout are important parameters influence overall control performance in Networked Control System (NCS. The goal of this research is to find a model of delay and dropout of data communication link in the NCS. Experiments have been done in this research to a water level control of boiler tank as part of the NCS based on internet communication network using High Speed Packet Access (HSPA cellular technology. By this experiments have been obtained closed-loop system response as well as data delay and dropout of data packets. This research contributes on modeling of the NCS which is combination of controlled plant and data communication link. Another contribution is statistical model of delay and dropout on the NCS.

  18. Therapist effects on dropout from a college counseling center practice research network.

    Science.gov (United States)

    Xiao, Henry; Castonguay, Louis G; Janis, Rebecca A; Youn, Soo Jeong; Hayes, Jeffrey A; Locke, Benjamin D

    2017-07-01

    Dropout has been a pervasive and costly problem in psychotherapy, particularly for college counseling centers. The present study examined potential predictors of dropout using a large data set (N = 10,147 clients, 481 therapists) that was gathered through a college counseling center practice research network as a replication and extension of recent findings regarding therapist effects on dropout. The final model resulted in a dropout rate of 15.9% and a therapist effect of 9.51% on dropout variance. Therapist demographic variables were investigated, though none were found to be significant. Variables found to be predictive of increased likelihood of dropping out included higher levels of general presenting concerns, alcohol-related distress, and current financial stress. Ultimately, this study showed that therapists may play an important role in the likelihood of client dropout, and that additional research should be conducted to identify additional predictors, particularly at the therapist and center level. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  19. DATA MINING IN HIGHER EDUCATION : UNIVERSITY STUDENT DROPOUT CASE STUDY

    OpenAIRE

    Ghadeer S. Abu-Oda; Alaa M. El-Halees

    2015-01-01

    In this paper, we apply different data mining approaches for the purpose of examining and predicting students’ dropouts through their university programs. For the subject of the study we select a total of 1290 records of computer science students Graduated from ALAQSA University between 2005 and 2011. The collected data included student study history and transcript for courses taught in the first two years of computer science major in addition to student GPA , high school average ...

  20. High mitogenomic evolutionary rates and time dependency.

    NARCIS (Netherlands)

    Subramanian, S.; Denver, D.R.; Millar, C.D.; Heupink, T.; Aschrafi, A.; Emslie, S.D.; Baroni, C.; Lambert, D.M.

    2009-01-01

    Using entire modern and ancient mitochondrial genomes of Adelie penguins (Pygoscelis adeliae) that are up to 44000 years old, we show that the rates of evolution of the mitochondrial genome are two to six times greater than those estimated from phylogenetic comparisons. Although the rate of

  1. Dropout of Children from schools in Nepal

    OpenAIRE

    Wagle, Dhirendra

    2012-01-01

    Nepal, a developing country of the south-asian region has bigger problem of children not completing the full cycle of basic education. In other words, large number of children dropout of schools, especially in the primary and secondary level of schooling. Especially, the situation is worse for those of the backward and socially disadvantaged populations and of the rural and the remote areas. Being in this frame, this study focused on the reasons of dropout of children from schools and the pos...

  2. Cheetah: A high frame rate, high resolution SWIR image camera

    Science.gov (United States)

    Neys, Joel; Bentell, Jonas; O'Grady, Matt; Vermeiren, Jan; Colin, Thierry; Hooylaerts, Peter; Grietens, Bob

    2008-10-01

    A high resolution, high frame rate InGaAs based image sensor and associated camera has been developed. The sensor and the camera are capable of recording and delivering more than 1700 full 640x512pixel frames per second. The FPA utilizes a low lag CTIA current integrator in each pixel, enabling integration times shorter than one microsecond. On-chip logics allows for four different sub windows to be read out simultaneously at even higher rates. The spectral sensitivity of the FPA is situated in the SWIR range [0.9-1.7 μm] and can be further extended into the Visible and NIR range. The Cheetah camera has max 16 GB of on-board memory to store the acquired images and transfer the data over a Gigabit Ethernet connection to the PC. The camera is also equipped with a full CameralinkTM interface to directly stream the data to a frame grabber or dedicated image processing unit. The Cheetah camera is completely under software control.

  3. Towards dropout training for convolutional neural networks.

    Science.gov (United States)

    Wu, Haibing; Gu, Xiaodong

    2015-11-01

    Recently, dropout has seen increasing use in deep learning. For deep convolutional neural networks, dropout is known to work well in fully-connected layers. However, its effect in convolutional and pooling layers is still not clear. This paper demonstrates that max-pooling dropout is equivalent to randomly picking activation based on a multinomial distribution at training time. In light of this insight, we advocate employing our proposed probabilistic weighted pooling, instead of commonly used max-pooling, to act as model averaging at test time. Empirical evidence validates the superiority of probabilistic weighted pooling. We also empirically show that the effect of convolutional dropout is not trivial, despite the dramatically reduced possibility of over-fitting due to the convolutional architecture. Elaborately designing dropout training simultaneously in max-pooling and fully-connected layers, we achieve state-of-the-art performance on MNIST, and very competitive results on CIFAR-10 and CIFAR-100, relative to other approaches without data augmentation. Finally, we compare max-pooling dropout and stochastic pooling, both of which introduce stochasticity based on multinomial distributions at pooling stage. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. GENDER STEREOTYPES IN THE SCHOOL DROPOUT: CASE EL FUERTE, SINALOA

    Directory of Open Access Journals (Sweden)

    Rosalva Ruíz-Ramírez

    2014-07-01

    Full Text Available Gender stereotypes are accepted preconceptions of what should be a man and a woman. Affect all areas of life, in the relationships that stablished in the family and the school. Within education, these stereotypes are reflected in the access, retention and completion of education degrees, as well as the area of study that preferred the women and men. They also have different effects on the causes of dropout depending on the gender to which they belong. This article aims to show the influence of gender stereotypes on dropout students and high school students in rural areas, specifically in three schools located in the municipality of El Fuerte, Sinaloa, the academic unit (AU San Blas and its extensions La Constancia and Las Higueras of Los Natoches. The results were obtained through a wider investigation in 2013.

  5. Dropout from exercise randomized controlled trials among people with depression: A meta-analysis and meta regression.

    Science.gov (United States)

    Stubbs, Brendon; Vancampfort, Davy; Rosenbaum, Simon; Ward, Philip B; Richards, Justin; Soundy, Andrew; Veronese, Nicola; Solmi, Marco; Schuch, Felipe B

    2016-01-15

    Exercise has established efficacy in improving depressive symptoms. Dropouts from randomized controlled trials (RCT's) pose a threat to the validity of this evidence base, with dropout rates varying across studies. We conducted a systematic review and meta-analysis to investigate the prevalence and predictors of dropout rates among adults with depression participating in exercise RCT's. Three authors identified RCT's from a recent Cochrane review and conducted updated searches of major electronic databases from 01/2013 to 08/2015. We included RCT's of exercise interventions in people with depression (including major depressive disorder (MDD) and depressive symptoms) that reported dropout rates. A random effects meta-analysis and meta regression were conducted. Overall, 40 RCT's were included reporting dropout rates across 52 exercise interventions including 1720 people with depression (49.1 years (range=19-76 years), 72% female (range=0-100)). The trim and fill adjusted prevalence of dropout across all studies was 18.1% (95%CI=15.0-21.8%) and 17.2% (95%CI=13.5-21.7, N=31) in MDD only. In MDD participants, higher baseline depressive symptoms (β=0.0409, 95%CI=0.0809-0.0009, P=0.04) predicted greater dropout, whilst supervised interventions delivered by physiotherapists (β=-1.2029, 95%CI=-2.0967 to -0.3091, p=0.008) and exercise physiologists (β=-1.3396, 95%CI=-2.4478 to -0.2313, p=0.01) predicted lower dropout. A comparative meta-analysis (N=29) established dropout was lower in exercise than control conditions (OR=0.642, 95%CI=0.43-0.95, p=0.02). Exercise is well tolerated by people with depression and drop out in RCT's is lower than control conditions. Thus, exercise is a feasible treatment, in particular when delivered by healthcare professionals with specific training in exercise prescription. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Modified Convolutional Neural Network Based on Dropout and the Stochastic Gradient Descent Optimizer

    Directory of Open Access Journals (Sweden)

    Jing Yang

    2018-03-01

    Full Text Available This study proposes a modified convolutional neural network (CNN algorithm that is based on dropout and the stochastic gradient descent (SGD optimizer (MCNN-DS, after analyzing the problems of CNNs in extracting the convolution features, to improve the feature recognition rate and reduce the time-cost of CNNs. The MCNN-DS has a quadratic CNN structure and adopts the rectified linear unit as the activation function to avoid the gradient problem and accelerate convergence. To address the overfitting problem, the algorithm uses an SGD optimizer, which is implemented by inserting a dropout layer into the all-connected and output layers, to minimize cross entropy. This study used the datasets MNIST, HCL2000, and EnglishHand as the benchmark data, analyzed the performance of the SGD optimizer under different learning parameters, and found that the proposed algorithm exhibited good recognition performance when the learning rate was set to [0.05, 0.07]. The performances of WCNN, MLP-CNN, SVM-ELM, and MCNN-DS were compared. Statistical results showed the following: (1 For the benchmark MNIST, the MCNN-DS exhibited a high recognition rate of 99.97%, and the time-cost of the proposed algorithm was merely 21.95% of MLP-CNN, and 10.02% of SVM-ELM; (2 Compared with SVM-ELM, the average improvement in the recognition rate of MCNN-DS was 2.35% for the benchmark HCL2000, and the time-cost of MCNN-DS was only 15.41%; (3 For the EnglishHand test set, the lowest recognition rate of the algorithm was 84.93%, the highest recognition rate was 95.29%, and the average recognition rate was 89.77%.

  7. Electron heat flux dropouts in the solar wind: Evidence for interplanetary magnetic field reconnection?

    International Nuclear Information System (INIS)

    McComas, D.J.; Gosling, J.T.; Phillips, J.L.; Bame, S.J.; Luhmann, J.G.; Smith, E.J.

    1989-01-01

    Electron heat flux dropout events have been observed in the solar wind using the ISEE 3 plasma electron data set. These events manifest themselves as dropouts of the solar wind halo electrons which are normally found streaming outward along the local magnetic field. These dropouts leave nearly isotropic distributions of solar wind halo electrons, and consequently, the heat flux in these events is reduced to near the observational noise level. We have examined ISEE 3 data from shortly after launch (August 16, 1978) through the end of 1978 and identified 25 such events ranging in duration from 20 min to over 11 hours. Comparison with the ISEE 3 magnetometer data indicates that these intervals nearly always occur in conjunction with large rotations of the interplanetary magnetic field. Statistical analyses of the plasma and magnetic field data for the 25 dropout intervals indicate that heat flux dropouts generally occur in association with high plasma densities low plasma velocities, low ion and electron temperatures, and low magnetic field magnitudes. A second set of 25 intervals chosen specifically to lie at large field rotations, but at times at which not heat flux dropouts were observed, do not show these characteristic plalsma variations. This suggests that the dropout intervals comprise a unique set of events. Since the hot halo electrons normally found streaming outward from the Sun along the interplanetary magnetic field (the solar wind electron heat flux) are a result of direct magnetic connection to the hot solar corona, heat flux dropout intervals may indicate that the spacecraft is sampling plasma regimes which are magnetically disconnected from the Sun and instead are connected to the outer heliosphere at both ends

  8. Evaluation of factors associated with psychiatric patient dropout at a university outpatient clinic in Japan.

    Science.gov (United States)

    Minamisawa, Atsumi; Narumoto, Jin; Yokota, Isao; Fukui, Kenji

    2016-01-01

    Patient dropout from treatment can lead to a deterioration in clinical condition, thereby increasing the need for more intensive therapy that incurs substantial social and economic losses. The aim of this study was to identify factors related to psychiatric patient dropout at a university outpatient clinic in Japan. We retrospectively examined the medical charts of new psychiatric patients who were diagnosed with either a mood disorder (International Classification of Diseases, 10th revision, code: F3) or an anxiety disorder (F4) in the outpatient clinic at Kyoto Prefectural University of Medicine Hospital in Kyoto, Japan, between April 2010 and March 2013. The baseline characteristics of the patients (age, sex, Global Assessment of Functioning score, Clinical Global Impression-Severity of Illness score, education, occupation, marital status, duration of treatment, and prior treatment history), treating psychiatrist experience in years, and sex concordance between the patients and their treating psychiatrists were analyzed using Cox regression models. From among 1,626 eligible new patients during the study period, 532 patients were enrolled in the study (F3: n=176; F4: n=356). The dropout rate was 35.7%, which was similar to that of previous studies. Higher educational level, being married, and lower Global Assessment of Functioning scores were associated with a lower dropout rate. Although psychiatrist experience was not significantly associated with patient dropout in the multivariate analysis, patients treated by less experienced psychiatrists had a higher hazard ratio for dropout (1.31; 95% confidence interval: 0.94-1.85). In order to reduce the dropout rate, special focus should be placed on patients with the factors identified in this study, and young psychiatrists should undergo further education to foster adherence.

  9. Factors affecting dropout rates for teacher training courses in the first third of the twentieth in the Cordoba teacher training schools’ Factores de incidencia en el abandono de los estudios de magisterio en el primer tercio del siglo XX en las escuelas normales de Córdoba

    Directory of Open Access Journals (Sweden)

    Antonia RAMÍREZ GARCÍA

    2013-02-01

    Full Text Available The aim of this paper is to determine which variables affected the dropout rate for the academic curricula applied in 1903, 1914 and 1931. The application of the quantitative methodology to the History of the Education is limited, but it opens new options of investigation. The tool used to compile information was a questionnaire applied to a stratified sample of 618 subjects. Statistical inference was used to prove or disprove the hypotheses. The results revolved around the conditioning factors that affected the students, for example gender (52% and 48% for male and female students, respectively, 51.6% of the students followed an official curriculum, and the dropout rate was 45%. The findings indicate that the dropout rate was influenced by the gender, the curriculum studied and the mode of teaching chosen.El objetivo de esta investigación es la identificación de las variables intervinientes en el abandono de los estudios de magisterio en las Escuelas Normales cordobesas durante los planes de estudio de 1903, 1914 y 1931. La aplicación de la metodología cuantitativa a la Historia de la Educación es reducida, pero abre nuevas opciones de investigación. La herramienta de recogida de información empleada fue un cuestionario-plantilla aplicado a una muestra estratificada de 618 sujetos. Para probar o rechazar las hipótesis se recurrió a la estadística inferencial. Los resultados han girado alrededor de los condicionantes del alumnado: sexo (52 y 48% para hombres y mujeres respectivamente, seguimiento de una enseñanza oficial en el 51,6% del alumnado y del abandono de los estudios en el 45% de los casos. Las conclusiones señalan que el abandono de los estudios de magisterio quedó condicionado por el sexo del alumnado, el plan de estudios cursado y la modalidad de enseñanza seleccionada.

  10. A path model analysis on predictors of dropout (at 6 and 12 months) during the weight loss interventions in endocrinology outpatient division.

    Science.gov (United States)

    Perna, Simone; Spadaccini, Daniele; Riva, Antonella; Allegrini, Pietro; Edera, Chiara; Faliva, Milena Anna; Peroni, Gabriella; Naso, Maurizio; Nichetti, Mara; Gozzer, Carlotta; Vigo, Beatrice; Rondanelli, Mariangela

    2018-02-22

    This study aimed to identify the dropout rate at 6 and 12 months from the first outpatient visit, and to analyze dropout risk factors among the following areas: biochemical examinations, anthropometric measures, psychological tests, personal data, and life attitude such as smoking, physical activity, and pathologies. This is a retrospective longitudinal observational study. Patients undergo an outpatient endocrinology visit, which includes collecting biographical data, anthropometric measurements, physical and pathological history, psychological tests, and biochemical examinations. The sample consists of 913 subjects (682 women and 231 men), with an average age of 50.88 years (±15.80) for the total sample, with a BMI of 33.11 ± 5.65 kg/m 2 . 51.9% of the patients abandoned therapy at 6 months after their first visit, and analyzing the dropout rate at 12 months, it appears that 69.5% of subjects abandon therapy. The main predictor of dropout risk factors at 6 and 12 months is the weight loss during the first 3 months (p dropout at 12 months. Patients who introduced physical activity had a reduction of - 17% (at 6 months) and -13% (at 12 months) of dropout risk (p dropout vs. other categories of worker (i = 0.58; p Dropout risk at 12 months decrease in patients with a previous history of cancer, Endocrine and psychic and behavioral disorders (p dropout.

  11. Ceramic high-rate timing RPCs

    International Nuclear Information System (INIS)

    Lopes, L.; Ferreira Marques, R.; Fonte, P.; Hennetier, L.; Pereira, A.; Sousa Correia, A.M.

    2006-01-01

    Following some previous work, we report here considerable improvements on the counting rate capability of timing RPCs by the use of ceramic electrodes with a resistivity of 10 9 Ω.cm. The X-ray sensitivity of the detector depends linearly on the counting rate with a slope of 9% per 100 kHz/cm 2 , free from charge depletion effects, while keeping a timing accuracy, measured with 511 keV synchronous photon pairs, around 90 ps σ up to 75 kHz/cm 2

  12. Rule-of-thumb adjustment of sample sizes to accommodate dropouts in a two-stage analysis of repeated measurements.

    Science.gov (United States)

    Overall, John E; Tonidandel, Scott; Starbuck, Robert R

    2006-01-01

    Recent contributions to the statistical literature have provided elegant model-based solutions to the problem of estimating sample sizes for testing the significance of differences in mean rates of change across repeated measures in controlled longitudinal studies with differentially correlated error and missing data due to dropouts. However, the mathematical complexity and model specificity of these solutions make them generally inaccessible to most applied researchers who actually design and undertake treatment evaluation research in psychiatry. In contrast, this article relies on a simple two-stage analysis in which dropout-weighted slope coefficients fitted to the available repeated measurements for each subject separately serve as the dependent variable for a familiar ANCOVA test of significance for differences in mean rates of change. This article is about how a sample of size that is estimated or calculated to provide desired power for testing that hypothesis without considering dropouts can be adjusted appropriately to take dropouts into account. Empirical results support the conclusion that, whatever reasonable level of power would be provided by a given sample size in the absence of dropouts, essentially the same power can be realized in the presence of dropouts simply by adding to the original dropout-free sample size the number of subjects who would be expected to drop from a sample of that original size under conditions of the proposed study.

  13. Dropouts and Budgets: A Test of a Dropout Reduction Model among Students in Israeli Higher Education

    Science.gov (United States)

    Bar-Am, Ran; Arar, Osama

    2017-01-01

    This article deals with the problem of student dropout during the first year in a higher education institution. To date, no model on a budget has been developed and tested to prevent dropout among Engineering Students. This case study was conducted among first-year students taking evening classes in two practical engineering colleges in Israel.…

  14. Explaining the Rise in Danish Vocational Education System Dropouts: The Effect of a Youth Unemployment Program

    DEFF Research Database (Denmark)

    Munk, Martin D.; Park, Do-Yeun

    This project focuses on the impact of Denmark’s Youth Unemployment Program(YUP) enacted in late 1990s on the rise in VET dropout rates. The Youth Unemployment Program targeted unemployed, low-educated youth to strengthen the employment possibilities and to motivate for them to undertake an educat......This project focuses on the impact of Denmark’s Youth Unemployment Program(YUP) enacted in late 1990s on the rise in VET dropout rates. The Youth Unemployment Program targeted unemployed, low-educated youth to strengthen the employment possibilities and to motivate for them to undertake...... an education. If the Youth Unemployment Program incentivized less capable/ambitious students to enter vocational education, it would increase the dropout rates via selection. This project investigates whether the program had an effect on the population characteristics of incoming VET students and the resulting...

  15. Transition to high rate aerospace NDI processes

    Science.gov (United States)

    Vanderheiden, Bert; Thomson, Clint; Ivakhnenko, Igor; Garner, Chuck

    2018-04-01

    With the rapidly expanding use of carbon fiber composite materials in military and commercial aircraft, processes to manufacture and inspect the structural components must evolve to ensure economic viability. Inspection techniques which were developed to inspect products produced at a rate of one or two structures a month are not fast or flexible enough to inspect more than 8500 parts per month. This presentation describes the evolution of phased array ultrasonic inspection systems to provide the increased rate capacity, the flexibility to accommodate multiple unique designs, and the ability to rapidly adjust to product design changes. The paper will describe how system developments were made in response to new programs resulting in a much less expensive, higher degree of accuracy, increased flexibility, and lower cycle time inspections.

  16. High exposure rate hardware ALARA plan

    International Nuclear Information System (INIS)

    Nellesen, A.L.

    1996-10-01

    This as low as reasonably achievable review provides a description of the engineering and administrative controls used to manage personnel exposure and to control contamination levels and airborne radioactivity concentrations. HERH waste is hardware found in the N-Fuel Storage Basin, which has a contact dose rate greater than 1 R/hr and used filters. This waste will be collected in the fuel baskets at various locations in the basins

  17. Why Are Real Interest Rates So High?

    OpenAIRE

    Zvi Bodie; Alex Kane; Robert L. McDonald

    1983-01-01

    This paper applies the Capital Asset Pricing Model to help explain the anomalous behavior of real interest rates during the last several years. Specifically,we are able to show that the increased volatility of bond prices since the change in Federal Reserve operating procedure in October 1979 has substantially increased the required real risk premium on long term bonds. We also consider and reject the possibility that increased risk alone accounts for the recent increase in the short-term rea...

  18. Dropout of a multidisciplinary treatment program for women with fibromyalgia

    Directory of Open Access Journals (Sweden)

    Tatiana Rehder Gonçalves

    2010-03-01

    Full Text Available Objective: To evaluate the dropout of a multidisciplinary treatment program in fibromyalgia (FM. Methods: An observational study conducted during the period of April 2000 to December 2005, including 133 women with fibromyalgia, participating in a multidisciplinary treatment program. Those who had left the treatment for two weeks or more were classified as inactive and contacted by telephone to record the reasons for their noncompliance, which were divided into four groups: 1 Family; 2 Occupations; 3 Medical; 4 Other Reasons. Results: When collecting data, 92 (69.4% women were considered inactive. There was no significant difference between noncompliance before and after six months of treatment. Of the total number of inactive women, 54 (40.8% participants left for medical reasons, 30 (22.6% for other reasons, 26 (19.4% for family reasons and 23 (17.2% due to occupation. There was no statistical difference between the motives of dropout according to the length of stay in the program (p> 0.05. Conclusion: We conclude that the multidisciplinary program for women with fibromyalgia had high levels of noncompliance, half of them occurred in the first six months. Among the main reasons reported for dropout, the medical reasons were more frequent.

  19. Influence of X and gamma radiation and bias conditions on dropout voltage of voltage regulators serial transistors

    International Nuclear Information System (INIS)

    Vukic, V.; Osmokrovic, P.; Stankovic, S.; Kovacevic, M.

    2005-01-01

    Research topic presented in this paper is degradation of characteristics of low-dropout voltage regulator's serial transistor during exposure of device to the ionizing radiation. Voltage regulators were exposed to X and γ radiation in two modes: without bias conditions, and with bias conditions and load. Tested circuits are representatives of the first and the second generation of low-dropout voltage regulators, with lateral and vertical PNP serial transistor: LM2940 and L4940. Experimental results of output voltage and serial dropout voltage change in function of total ionizing dose, during the medium-dose-rate exposure, were presented. (author) [sr

  20. When Does Premature Treatment Termination Occur? Examining Session-by-Session Dropout Among Clients with Gambling Disorder.

    Science.gov (United States)

    Pfund, Rory A; Peter, Samuel C; Whelan, James P; Meyers, Andrew W

    2018-06-01

    Premature termination challenges the successful outcomes of psychological treatments for gambling disorder. To date, research has primarily identified clients who are at particular risk for dropping out of treatment. A smaller but growing body of literature has investigated when dropout occurs. Typically, those studies have not considered improvement in psychological distress within their operationalizations of dropout and therefore may have misrepresented when dropout occurs. The current study examined when dropout occurs using an operationalization based on the criteria of attaining reliable change in a naturalistic sample of clients with gambling disorder, and the classification rates yielded from that operationalization were compared to the rates from a more common operationalization. Participants (n = 334) were clients meeting diagnostic criteria for gambling disorder at an outpatient private practice who completed a measure of psychological distress at baseline and prior to each subsequent treatment session. A survival analysis was conducted to determine temporal patterns of treatment dropout (i.e., clients who discontinued treatment before realizing reliable changes in psychological distress) and completion (i.e., clients who discontinued treatment after realizing reliable changes in distress) at each treatment session. Forty-nine percent of clients were classified as dropouts, and the majority of those clients did so in the first few sessions. The more common operationalization of dropout classified clients as dropouts when they had improved in their distress and clients as completers when they had not improved in their distress. Discussion centers on the implications of dropout occurring at various stages of treatment and future directions.

  1. High readmission rate after heart valve surgery

    DEFF Research Database (Denmark)

    Sibilitz, K L; Berg, S K; Thygesen, L C

    2015-01-01

    investigated. RESULTS: After valve surgery, the self-reported health was lower (Short Form-36 (SF-36) Physical Component Scale (PCS): 44.5 vs. 50.6 and Mental Component Scale (MCS): 51.9 vs. 55.0, pClinical signs......BACKGROUND: After heart valve surgery, knowledge on long-term self-reported health status and readmission is lacking. Thus, the optimal strategy for out-patient management after surgery remains unclear. METHODS: Using a nationwide survey with linkage to Danish registers with one year follow-up, we...... included all adults 6-12months after heart valve surgery irrespective of valve procedure, during Jan-June 2011 (n=867). Participants completed a questionnaire regarding health-status (n=742), and answers were compared with age- and sex-matched healthy controls. Readmission rates and mortality were...

  2. The reasons of dropout of sport in Hong Kong school athletes

    OpenAIRE

    Hassan, Abdul-Rahman; Lam, Michael Huen Sum; Ku, Susanna; Li, William Ho Cheung; Lee, Ka Yiu; Ho, Eva; Flint, Stuart W.; Wong, Anthony Siu Wo

    2017-01-01

    Dropout of sport is an issue in sport and public health domains. The aim of this study was to identify the potential dropout reasons of school athletes and to examine if their perception of dropout was affected by the previous dropout experience. There were 50 subjects who were divided into two groups based on their previous dropout experience (Dropout Group=22, No Dropout Group=28). They filled a questionnaire about potential dropout reasons of the current sport. Coach and teammates were two...

  3. Improving quantitative structure-activity relationship models using Artificial Neural Networks trained with dropout.

    Science.gov (United States)

    Mendenhall, Jeffrey; Meiler, Jens

    2016-02-01

    Dropout is an Artificial Neural Network (ANN) training technique that has been shown to improve ANN performance across canonical machine learning (ML) datasets. Quantitative Structure Activity Relationship (QSAR) datasets used to relate chemical structure to biological activity in Ligand-Based Computer-Aided Drug Discovery pose unique challenges for ML techniques, such as heavily biased dataset composition, and relatively large number of descriptors relative to the number of actives. To test the hypothesis that dropout also improves QSAR ANNs, we conduct a benchmark on nine large QSAR datasets. Use of dropout improved both enrichment false positive rate and log-scaled area under the receiver-operating characteristic curve (logAUC) by 22-46 % over conventional ANN implementations. Optimal dropout rates are found to be a function of the signal-to-noise ratio of the descriptor set, and relatively independent of the dataset. Dropout ANNs with 2D and 3D autocorrelation descriptors outperform conventional ANNs as well as optimized fingerprint similarity search methods.

  4. Psychological well-being as a predictor of dropout among recently qualified Danish eldercare workers

    DEFF Research Database (Denmark)

    Giver, Hanne; Faber, Anne; Hannerz, Harald

    2010-01-01

    BACKGROUND: The eldercare sector is characterized by a shortage of labour and a high turnover rate, which constitutes a major challenge for the ageing societies of western Europe. The aim of the present study was to investigate if a low level of psychological well-being at the time of graduation...... predicts dropout among eldercare workers two years later. METHODS: We included 4,968 female eldercare trainees in this prospective study, recruited from 27 of the 28 Danish colleges for eldercare. Psychological well-being in 2004 was measured with the five-item Mental Health Inventory (MHI-5) of the 36......-item Short-Form Health Survey (SF-36). We linked the survey data with national register data to obtain information about labour market attachment two years after qualification. RESULTS: In 2006, 37% of all participants had left the eldercare sector. Compared to participants with high psychological well...

  5. High dose rate brachytherapy source measurement intercomparison.

    Science.gov (United States)

    Poder, Joel; Smith, Ryan L; Shelton, Nikki; Whitaker, May; Butler, Duncan; Haworth, Annette

    2017-06-01

    This work presents a comparison of air kerma rate (AKR) measurements performed by multiple radiotherapy centres for a single HDR 192 Ir source. Two separate groups (consisting of 15 centres) performed AKR measurements at one of two host centres in Australia. Each group travelled to one of the host centres and measured the AKR of a single 192 Ir source using their own equipment and local protocols. Results were compared to the 192 Ir source calibration certificate provided by the manufacturer by means of a ratio of measured to certified AKR. The comparisons showed remarkably consistent results with the maximum deviation in measurement from the decay-corrected source certificate value being 1.1%. The maximum percentage difference between any two measurements was less than 2%. The comparisons demonstrated the consistency of well-chambers used for 192 Ir AKR measurements in Australia, despite the lack of a local calibration service, and served as a valuable focal point for the exchange of ideas and dosimetry methods.

  6. Are Barbie and Ken too cool for school? A case-control study on the relation between gender and dropout.

    Science.gov (United States)

    Theunissen, Marie-José; de Man, Inge; Verdonk, Petra; Bosma, Hans; Feron, Frans

    2015-02-01

    As school dropout is an important public health problem that needs to be addressed, we set out to examine whether and how, beyond the well-known effects of sex, gender beliefs and self-reported masculinity and femininity are related to school dropout. The study used a case-control design, consisting of 330 dropout cases and 330 controls still attending school. The respondents, aged between 18 and 23 years, living in the south-east of the Netherlands, were sent a self-administered questionnaire. Separate logistic regression analyses for the male and female participants were used to explore the relation between dropout and gender, controlling for sociodemographic determinants. As indicated by significant curvilinearity, young women were less likely to drop out when they occupied an intermediate positions on the gender variables. Odds of dropout were elevated among highly masculine women (odds ratio = 2.1, 95% confidence interval: 1.1-4.1), and, as indicated by significant interactions, also among highly masculine men with strong normative masculine beliefs and in feminine men who simultaneously considered themselves low on masculinity. Beyond sex, gender is important in the explanation of school dropout. To prevent dropout, public health professionals should assess, monitor and intervene on the basis of gender characteristics. © The Author 2014. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

  7. High-deposition-rate ceramics synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Allendorf, M.D.; Osterheld, T.H.; Outka, D.A. [Sandia National Laboratories, Livermore, CA (United States)] [and others

    1995-05-01

    Parallel experimental and computational investigations are conducted in this project to develop validated numerical models of ceramic synthesis processes. Experiments are conducted in the High-Temperature Materials Synthesis Laboratory in Sandia`s Combustion Research Facility. A high-temperature flow reactor that can accommodate small preforms (1-3 cm diameter) generates conditions under which deposition can be observed, with flexibility to vary both deposition temperature (up to 1500 K) and pressure (as low as 10 torr). Both mass spectrometric and laser diagnostic probes are available to provide measurements of gas-phase compositions. Experiments using surface analytical techniques are also applied to characterize important processes occuring on the deposit surface. Computational tools developed through extensive research in the combustion field are employed to simulate the chemically reacting flows present in typical industrial reactors. These include the CHEMKIN and Surface-CHEMKIN suites of codes, which permit facile development of complex reaction mechanisms and vastly simplify the implementation of multi-component transport and thermodynamics. Quantum chemistry codes are also used to estimate thermodynamic and kinetic data for species and reactions for which this information is unavailable.

  8. Liquid Argon Calorimeter performance at High Rates

    CERN Document Server

    Seifert, F; The ATLAS collaboration

    2013-01-01

    The expected increase of luminosity at HL-LHC by a factor of ten with respect to LHC luminosities has serious consequences for the signal reconstruction, radiation hardness requirements and operations of the ATLAS liquid argon calorimeters in the endcap, respectively forward region. Small modules of each type of calorimeter have been built and exposed to a high intensity proton beam of 50 GeV at IHEP/Protvino. The beam is extracted via the bent crystal technique, offering the unique opportunity to cover intensities ranging from $10^6$ p/s up to $3\\cdot10^{11}$ p/s. This exceeds the deposited energy per time expected at HL-LHC by more than a factor of 100. The correlation between beam intensity and the read-out signal has been studied. The data show clear indications of pulse shape distortion due to the high ionization build-up, in agreement with MC expectations. This is also confirmed from the dependence of the HV currents on beam intensity.

  9. The influence of ethnic segregation and school mobility in primary education on high school dropout : evidence from regression discontinuity at a contextual tipping point

    NARCIS (Netherlands)

    Ong, C.; de Witte, K.

    2013-01-01

    This paper investigates the influence of ethnic composition and school mobility at the primary school-level on the propensity to drop out of high school. Using rich school and neighbourhood administrative data, we observe that (i) frequent school movers have a 2.6 times higher likelihood of early

  10. UV CONTINUUM SLOPE AND DUST OBSCURATION FROM z ∼ 6 TO z ∼ 2: THE STAR FORMATION RATE DENSITY AT HIGH REDSHIFT

    International Nuclear Information System (INIS)

    Bouwens, R. J.; Illingworth, G. D.; Franx, M.; Chary, R.-R.; Meurer, G. R.; Ford, H.; Conselice, C. J.; Giavalisco, M.; Van Dokkum, P.

    2009-01-01

    We provide a systematic measurement of the rest-frame UV continuum slope β over a wide range in redshift (z ∼ 2-6) and rest-frame UV luminosity (0.1 L* z = 3 to 2 L* z= 3 ) to improve estimates of the star formation rate (SFR) density at high redshift. We utilize the deep optical and infrared data (Advanced Camera for Surveys/NICMOS) over the Chandra Deep Field-South and Hubble Deep Field-North Great Observatories Origins Deep Survey fields, as well as the UDF for our primary UBVi 'dropout' Lyman Break Galaxy sample. We also use strong lensing clusters to identify a population of very low luminosity, high-redshift dropout galaxies. We correct the observed distributions for both selection biases and photometric scatter. We find that the UV-continuum slope of the most luminous galaxies is substantially redder at z ∼ 2-4 than it is at z ∼ 5-6 (from ∼-2.4 at z ∼ 6 to ∼-1.5 at z ∼ 2). Lower luminosity galaxies are also found to be bluer than higher luminosity galaxies at z ∼ 2.5 and z ∼ 4. We do not find a large number of galaxies with β's as red as -1 in our dropout selections at z ∼ 4, and particularly at z ∼> 5, even though such sources could be readily selected from our data (and also from Balmer Break Galaxy searches at z ∼ 4). This suggests that star-forming galaxies at z ∼> 5 almost universally have very blue UV-continuum slopes, and that there are not likely to be a substantial number of dust-obscured galaxies at z ∼> 5 that are missed in 'dropout' searches. Using the same relation between UV-continuum slope and dust extinction as has been found to be appropriate at both z ∼ 0 and z ∼ 2, we estimate the average dust extinction of galaxies as a function of redshift and UV luminosity in a consistent way. As expected, we find that the estimated dust extinction increases substantially with cosmic time for the most UV luminous galaxies, but remains small (∼ 4.

  11. Effect of child marriage on girls' school dropout in Nepal: Analysis of data from the Multiple Indicator Cluster Survey 2014.

    Directory of Open Access Journals (Sweden)

    Kazutaka Sekine

    Full Text Available School dropout and child marriage are interrelated outcomes that have an enormous impact on adolescent girls. However, the literature reveals gaps in the empirical evidence on the link between child marriage and the dropout of girls from school. This study identifies the 'tipping point' school grades in Nepal when the risk of dropout due to marriage is highest, measures the effect of child marriage on girls' school dropout rates, and assesses associated risk factors. Weighted percentages were calculated to examine the grades at highest risk and the distribution of reasons for discontinuing school. Using the Nepal Multiple Indicator Cluster Survey (MICS 2014 data, we estimated the effect of marriage on school attendance and dropout among girls aged 15-17 by constructing logistic regression models. A multivariate logistic regression model was used to assess risk factors of school dropout due to child marriage. It was found that early marriage is the most common reason given for leaving school. Overall, the risk of school dropout due to marriage heightens after girls complete the fifth or sixth grade. The risk of girls' dropping out peaks in the seventh and eighth grades and remains noteworthy in the ninth and tenth grades. Married girls in Nepal are 10 times more likely to drop out than their unmarried peers. Little or no education of the household head, belonging to the Kirat religion, and membership of a traditionally disadvantaged social class each elevate the risk of school dropout due to early marriage. The findings underscore the need to delay girl's marriage so as to reduce girls' school dropout in Nepal. School-based programmes aimed at preventing child marriage should target girls from the fifth grade because they are at increased risk of dropping out, as well as prioritizing girls from disadvantaged groups.

  12. High School Graduation Rates:Alternative Methods and Implications

    OpenAIRE

    Jing Miao; Walt Haney

    2004-01-01

    The No Child Left Behind Act has brought great attention to the high school graduation rate as one of the mandatory accountability measures for public school systems. However, there is no consensus on how to calculate the high school graduation rate given the lack of longitudinal databases that track individual students. This study reviews literature on and practices in reporting high school graduation rates, compares graduation rate estimates yielded from alternative methods, and estimates d...

  13. UV Continuum Slope and Dust Obscuration from z ~ 6 to z ~ 2: The Star Formation Rate Density at High Redshift

    Science.gov (United States)

    Bouwens, R. J.; Illingworth, G. D.; Franx, M.; Chary, R.-R.; Meurer, G. R.; Conselice, C. J.; Ford, H.; Giavalisco, M.; van Dokkum, P.

    2009-11-01

    We provide a systematic measurement of the rest-frame UV continuum slope β over a wide range in redshift (z ~ 2-6) and rest-frame UV luminosity (0.1 L* z = 3 to 2 L* z = 3) to improve estimates of the star formation rate (SFR) density at high redshift. We utilize the deep optical and infrared data (Advanced Camera for Surveys/NICMOS) over the Chandra Deep Field-South and Hubble Deep Field-North Great Observatories Origins Deep Survey fields, as well as the UDF for our primary UBVi "dropout" Lyman Break Galaxy sample. We also use strong lensing clusters to identify a population of very low luminosity, high-redshift dropout galaxies. We correct the observed distributions for both selection biases and photometric scatter. We find that the UV-continuum slope of the most luminous galaxies is substantially redder at z ~ 2-4 than it is at z ~ 5-6 (from ~-2.4 at z ~ 6 to ~-1.5 at z ~ 2). Lower luminosity galaxies are also found to be bluer than higher luminosity galaxies at z ~ 2.5 and z ~ 4. We do not find a large number of galaxies with β's as red as -1 in our dropout selections at z ~ 4, and particularly at z gsim 5, even though such sources could be readily selected from our data (and also from Balmer Break Galaxy searches at z ~ 4). This suggests that star-forming galaxies at z gsim 5 almost universally have very blue UV-continuum slopes, and that there are not likely to be a substantial number of dust-obscured galaxies at z gsim 5 that are missed in "dropout" searches. Using the same relation between UV-continuum slope and dust extinction as has been found to be appropriate at both z ~ 0 and z ~ 2, we estimate the average dust extinction of galaxies as a function of redshift and UV luminosity in a consistent way. As expected, we find that the estimated dust extinction increases substantially with cosmic time for the most UV luminous galaxies, but remains small (lsim2 times) at all times for lower luminosity galaxies. Because these same lower luminosity galaxies

  14. High School Graduation Rates:Alternative Methods and Implications

    Directory of Open Access Journals (Sweden)

    Jing Miao

    2004-10-01

    Full Text Available The No Child Left Behind Act has brought great attention to the high school graduation rate as one of the mandatory accountability measures for public school systems. However, there is no consensus on how to calculate the high school graduation rate given the lack of longitudinal databases that track individual students. This study reviews literature on and practices in reporting high school graduation rates, compares graduation rate estimates yielded from alternative methods, and estimates discrepancies between alternative results at national, state, and state ethnic group levels. Despite the graduation rate method used, results indicate that high school graduation rates in the U.S. have been declining in recent years and that graduation rates for black and Hispanic students lag substantially behind those of white students. As to graduation rate method preferred, this study found no evidence that the conceptually more complex methods yield more accurate or valid graduation rate estimates than the simpler methods.

  15. Comparing Dropouts and Persistence in E-Learning Courses

    Science.gov (United States)

    Levy, Yair

    2007-01-01

    Several studies have been conducted related to dropouts from on-campus and distance education courses. However, no clear definition of dropout from academic courses was provided. Consequently, this study proposes a clear and precise definition of dropout from academic courses in the context of e-learning courses. Additionally, it is documented in…

  16. The Effect of Minimum Wage Rates on High School Completion

    Science.gov (United States)

    Warren, John Robert; Hamrock, Caitlin

    2010-01-01

    Does increasing the minimum wage reduce the high school completion rate? Previous research has suffered from (1. narrow time horizons, (2. potentially inadequate measures of states' high school completion rates, and (3. potentially inadequate measures of minimum wage rates. Overcoming each of these limitations, we analyze the impact of changes in…

  17. High regression rate, high density hybrid fuels, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR program will investigate high energy density novel nanofuels combined with high density binders for use with an N2O oxidizer. Terves has developed...

  18. Dropout Prevalence and Associated Factors in Randomized Clinical Trials of Adolescents Treated for Depression: Systematic Review and Meta-analysis.

    Science.gov (United States)

    Rohden, Adriane Isabel; Benchaya, Mariana Canellas; Camargo, Roger Santos; Moreira, Taís de Campos; Barros, Helena M T; Ferigolo, Maristela

    2017-05-01

    Depression currently affects 350 million people, and its prevalence among adolescents is 4% to 8%. Adolescents who abandon antidepressant treatment or drop out of clinical trials are less likely to recover or experience a remission of symptoms because they are not being followed up by a medical team. The objective of this study was to analyze the dropout rates of randomized clinical trials of depressed adolescents receiving treatment with antidepressant drugs and the factors associated with nonadherence by summarizing this information in a systematic review and meta-analysis. Articles were retrieved from MEDLINE, EMBASE, Cochrane, Clinical Trial, PsycINFO, and Web of Science using the MeSH terms "depressive disorder," "randomized trials," and "adolescents." The evaluation of study quality was performed by using the Cochrane Handbook for Systematic Reviews of Interventions and the Jadad scale. The final sample included 50 articles, of which 44 presented dropout rates. The overall dropout prevalence was 23% (95% CI, 20-27; P dropout prevalence, respectively (33% [95% CI, 27-39], 45% [95% CI, 31-64], and 15% [95% CI, 13-17]). The adverse effects most associated with dropout were attempted suicide followed by mania, skin rash, and headache. Problems relating to clinical trials and family arbitration were also related with dropout. Serotonin/norepinephrine reuptake inhibitor treatment, adolescent age >16 years, and receiving medication were the only factors demonstrating a higher association with dropout rates. Selective serotonin reuptake inhibitors were linked to the lowest prevalence, probably due to fewer perceived problems with related adverse effects and higher efficacy in adolescents. Cognitive-behavioral therapy combined with pharmacotherapy produced a lower nonadherence prevalence; this approach can be an alternative to avoid dropouts and relapse. Prospero identifier: CRD42014013475. Copyright © 2017 Elsevier HS Journals, Inc. All rights reserved.

  19. A Maximum-Likelihood Method to Correct for Allelic Dropout in Microsatellite Data with No Replicate Genotypes

    Science.gov (United States)

    Wang, Chaolong; Schroeder, Kari B.; Rosenberg, Noah A.

    2012-01-01

    Allelic dropout is a commonly observed source of missing data in microsatellite genotypes, in which one or both allelic copies at a locus fail to be amplified by the polymerase chain reaction. Especially for samples with poor DNA quality, this problem causes a downward bias in estimates of observed heterozygosity and an upward bias in estimates of inbreeding, owing to mistaken classifications of heterozygotes as homozygotes when one of the two copies drops out. One general approach for avoiding allelic dropout involves repeated genotyping of homozygous loci to minimize the effects of experimental error. Existing computational alternatives often require replicate genotyping as well. These approaches, however, are costly and are suitable only when enough DNA is available for repeated genotyping. In this study, we propose a maximum-likelihood approach together with an expectation-maximization algorithm to jointly estimate allelic dropout rates and allele frequencies when only one set of nonreplicated genotypes is available. Our method considers estimates of allelic dropout caused by both sample-specific factors and locus-specific factors, and it allows for deviation from Hardy–Weinberg equilibrium owing to inbreeding. Using the estimated parameters, we correct the bias in the estimation of observed heterozygosity through the use of multiple imputations of alleles in cases where dropout might have occurred. With simulated data, we show that our method can (1) effectively reproduce patterns of missing data and heterozygosity observed in real data; (2) correctly estimate model parameters, including sample-specific dropout rates, locus-specific dropout rates, and the inbreeding coefficient; and (3) successfully correct the downward bias in estimating the observed heterozygosity. We find that our method is fairly robust to violations of model assumptions caused by population structure and by genotyping errors from sources other than allelic dropout. Because the data sets

  20. The american high school graduation rate : trends and levels

    OpenAIRE

    Heckman, James J.; LaFontaine, Paul A.

    2008-01-01

    This paper uses multiple data sources and a unified methodology to estimate the trends and levels of the U.S. high school graduation rate. Correcting for important biases that plague previous calculations, we establish that (a) the true high school graduation rate is substantially lower than the official rate issued by the National Center for Educational Statistics; (b) it has been declining over the past 40 years; (c) majority/minority graduation rate differentials are substantial and have n...

  1. Open-closed-loop iterative learning control for a class of nonlinear systems with random data dropouts

    Science.gov (United States)

    Cheng, X. Y.; Wang, H. B.; Jia, Y. L.; Dong, YH

    2018-05-01

    In this paper, an open-closed-loop iterative learning control (ILC) algorithm is constructed for a class of nonlinear systems subjecting to random data dropouts. The ILC algorithm is implemented by a networked control system (NCS), where only the off-line data is transmitted by network while the real-time data is delivered in the point-to-point way. Thus, there are two controllers rather than one in the control system, which makes better use of the saved and current information and thereby improves the performance achieved by open-loop control alone. During the transfer of off-line data between the nonlinear plant and the remote controller data dropout occurs randomly and the data dropout rate is modeled as a binary Bernoulli random variable. Both measurement and control data dropouts are taken into consideration simultaneously. The convergence criterion is derived based on rigorous analysis. Finally, the simulation results verify the effectiveness of the proposed method.

  2. Temporal dynamics of high repetition rate pulsed single longitudinal ...

    Indian Academy of Sciences (India)

    ing (GIG) cavity, single-mode dye laser pumped by high repetition rate ... in a high loss cavity, a detailed theoretical study and optimization of cavity ..... rate for high conversion efficiency and longer pulse width of the single-mode dye laser.

  3. Psychological and Educational Variables in University Dropout

    Science.gov (United States)

    Bethencourt, Jose Tomas; Cabrera, Lidia; Hernandez, Juan Andres; Alvarez-Perez, Pedro; Gonzalez-Afonso, Miriam

    2008-01-01

    Introduction: The purpose of this research is to demonstrate that on the perceptions of university students, the student variables are seen as most important than the context variables to dropout their university studies. Method: The used methodology was cross-sectional or of cut, of retrospective type. 558 undergraduates were interviewed by…

  4. Quantum data locking for high-rate private communication

    OpenAIRE

    Lupo, Cosmo; Lloyd, Seth

    2015-01-01

    We show that, if the accessible information is used as a security quantifier, quantum channels with a certain symmetry can convey private messages at a tremendously high rate, as high as less than one bit below the rate of non-private classical communication. This result is obtained by exploiting the quantum data locking effect. The price to pay to achieve such a high private communication rate is that accessible information security is in general not composable. However, composable security ...

  5. High-Rate Strong-Signal Quantum Cryptography

    Science.gov (United States)

    Yuen, Horace P.

    1996-01-01

    Several quantum cryptosystems utilizing different kinds of nonclassical lights, which can accommodate high intensity fields and high data rate, are described. However, they are all sensitive to loss and both the high rate and the strong-signal character rapidly disappear. A squeezed light homodyne detection scheme is proposed which, with present-day technology, leads to more than two orders of magnitude data rate improvement over other current experimental systems for moderate loss.

  6. Relationship between Self-Reported Psychopathology and Future Dropout in a Mexican School

    Directory of Open Access Journals (Sweden)

    Pablo J Chalita

    2012-03-01

    Full Text Available School dropout has significant consequences for both individuals and societies. Only 21% of adults in Mexico achieve the equivalent of a high school education. We examined the relationship between school dropout and self-reported psychiatric symptoms in a middle school in a suburb of Mexico City. We used binomial logistic regression to examine the odd ratio of school dropout associated with student’s self-reported psychopathology. Two-hundred thirty seven students participated in the study. Psychosis (Odds Ratio (OR=8.0 (95% Confidence Interval (CI: 1.7-37.2, depression (OR=4.7 (95% CI: 2.2-9.7, tic disorders (OR=3.7 (95%CI: 1.4-9.5, ADHD (OR=3.2 (95%CI:1.5-6.4, and social phobia (OR=2.6 (95%CI: 1.2-5.8 were associated with increased risk of school dropout after controlling for age and gender as covariates. Our study suggested that students’ self-reported psychopathology is associated with increased school dropout in Mexico.

  7. Evaluation of factors associated with psychiatric patient dropout at a university outpatient clinic in Japan

    Directory of Open Access Journals (Sweden)

    Minamisawa A

    2016-09-01

    Full Text Available Atsumi Minamisawa,1 Jin Narumoto,1 Isao Yokota,2 Kenji Fukui1 1Department of Psychiatry, 2Department of Biostatistics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan Background: Patient dropout from treatment can lead to a deterioration in clinical condition, thereby increasing the need for more intensive therapy that incurs substantial social and economic losses. The aim of this study was to identify factors related to psychiatric patient dropout at a university outpatient clinic in Japan.Methods: We retrospectively examined the medical charts of new psychiatric patients who were diagnosed with either a mood disorder (International Classification of Diseases, 10th revision, code: F3 or an anxiety disorder (F4 in the outpatient clinic at Kyoto Prefectural University of Medicine Hospital in Kyoto, Japan, between April 2010 and March 2013. The baseline characteristics of the patients (age, sex, Global Assessment of Functioning score, Clinical Global Impression–Severity of Illness score, education, occupation, marital status, duration of treatment, and prior treatment history, treating psychiatrist experience in years, and sex concordance between the patients and their treating psychiatrists were analyzed using Cox regression models.Results: From among 1,626 eligible new patients during the study period, 532 patients were enrolled in the study (F3: n=176; F4: n=356. The dropout rate was 35.7%, which was similar to that of previous studies. Higher educational level, being married, and lower Global Assessment of Functioning scores were associated with a lower dropout rate. Although psychiatrist experience was not significantly associated with patient dropout in the multivariate analysis, patients treated by less experienced psychiatrists had a higher hazard ratio for dropout (1.31; 95% confidence interval: 0.94–1.85.Conclusion: In order to reduce the dropout rate, special focus should be placed on

  8. Drop-out from a drug treatment clinic and associated reasons.

    Science.gov (United States)

    Hoseinie, Leila; Gholami, Zhaleh; Shadloo, Behrang; Mokri, Azarakhsh; Amin-Esmaeili, Masoumeh; Rahimi-Movaghar, Afarin

    2017-05-01

    The aim of this study was to assess drop-out rates and associated reasons among patients at the Iranian National Center for Addiction Studies (INCAS) clinic. In a one-year period (April 2014 to March 2015), all patients with drug dependence who had been referred for treatment and attended for a first assessment were included in this study (N=242). Those who received treatment were followed until March 2016. Survival analysis showed that 70.2% had dropped out from treatment. Log rank test showed that treatment drop-out rates differed between the different approaches used (P < 0.001), with the lowest slope inbuprenorphine maintenance treatment and the highest in the detoxification programme. Drop-out rates within the first three months was 62% (SE= 0.05) and 82.4% (SE=0.03) for opioids and stimulants dependence, respectively. Analyses were performed using SPSS (Version 21.0) and STATA software, (version 13.0). From the patients' perspective, motivational inconsistencies were considered as the main reason for not starting or leaving treatment. The findings of this study could give service providers a better grasp of drop-out rates and the associated reasons.

  9. The Reasons of School Dropouts in Higher Education: Babaeski Vocational College Case

    Science.gov (United States)

    Can, Ertug; Aktas, Fatma Oya; Arpacioglu, Isil Tuzun

    2017-01-01

    In Turkey, nearly 400.000 higher education students have left university education in the last 3 years. This figure is an indication of a negative situation. Turkey is in the first place in terms of school dropout rates within the European Higher Education Area (EHEA). After completing primary and secondary education and passing the necessary…

  10. Socioeconomic differences in school dropout among young adults: the role of social relations.

    Science.gov (United States)

    Winding, Trine Nøhr; Andersen, Johan Hviid

    2015-10-15

    School dropout in adolescence is an important social determinant of health inequality in a lifetime perspective. It is commonly accepted that parental background factors are associated with later dropout, but to what extent social relations mediate this association is not yet fully understood. To investigate the effect of social relations on the association between parental socioeconomic position and school dropout in the Danish youth cohort Vestliv. This prospective study used data from questionnaires in 2004 and 2007 and register data in 2004 and 2010. The study population consisted of 3,054 persons born in 1989. Information on dropout was dichotomised into those who had completed a secondary education/were still attending one and those who had dropped out/had never attended a secondary education. Logistic regression analyses were used to investigate associations between parental socioeconomic position and dropout at age 21, taking into account effects of social relations at age 15 and 18. A large proportion of young people were having problems with social relations at age 15 and 18. In general, social relations were strongly related to not completing a secondary education, especially among girls. For instance, 18-year-old girls finding family conflicts difficult to handle had a 2.6-fold increased risk of not completing a secondary education. Young people from low socioeconomic position families had approximately a 3-fold higher risk of not completing a secondary education compared to young people from high position families, and the estimates did not change greatly after adjustment for social relations with family or friends. Poor relations with teachers and classmates at age 18 explained a substantial part of the association between income and dropout among both girls and boys. The study confirmed a social gradient in completion of secondary education. Despite the fact that poor social relations at age 15 and 18 were related to dropout at age 21, social

  11. Pre-treatment Predictors of Dropout from Prolonged Exposure Therapy in Patients with Chronic Posttraumatic Stress Disorder and Comorbid Substance Use Disorders

    Science.gov (United States)

    Belleau, Emily L.; Chin, Eu Gene; Wanklyn, Sonya G.; Zambrano-Vazquez, Laura; Schumacher, Julie A.; Coffey, Scott F.

    2017-01-01

    Posttraumatic stress disorder (PTSD) and substance use disorders (SUDs) are commonly co-occurring disorders associated with more adverse consequences than PTSD alone. Prolonged exposure therapy (PE) is one of the most efficacious treatments for PTSD. However, among individuals with PTSD-SUD, 35–62% of individuals drop out of trauma-focused exposure treatments. Thus, it is important to identify predictors of PTSD treatment dropout among substance abusers with PTSD in order to gain information about adapting treatment strategies to enhance retention and outcomes. The current study explored pre-treatment predictors of early termination from PE treatment in a sample of 85 individuals receiving concurrent treatment for PTSD and a SUD in a residential treatment facility as part of a randomized controlled trial. The results indicated that less education and more anxiety sensitivity uniquely predicted PE treatment dropout. Demographic variables, PTSD severity, SUD severity, mental health comorbidities, and emotion regulation difficulties did not predict treatment dropout. These results suggest that adding pre-treatment interventions that address anxiety sensitivity, and promote social adjustment and cognitive flexibility, could possibly improve PE retention rates in clients with high anxiety or low education. PMID:28147254

  12. High rate flame synthesis of highly crystalline iron oxide nanorods

    International Nuclear Information System (INIS)

    Merchan-Merchan, W; Taylor, A M; Saveliev, A V

    2008-01-01

    Single-step flame synthesis of iron oxide nanorods is performed using iron probes inserted into an opposed-flow methane oxy-flame. The high temperature reacting environment of the flame tends to convert elemental iron into a high density layer of iron oxide nanorods. The diameters of the iron oxide nanorods vary from 10 to 100 nm with a typical length of a few microns. The structural characterization performed shows that nanorods possess a highly ordered crystalline structure with parameters corresponding to cubic magnetite (Fe 3 O 4 ) with the [100] direction oriented along the nanorod axis. Structural variations of straight nanorods such as bends, and T-branched and Y-branched shapes are frequently observed within the nanomaterials formed, opening pathways for synthesis of multidimensional, interconnected networks

  13. Predicting dropout in adolescents receiving therapy for depression.

    Science.gov (United States)

    O'Keeffe, Sally; Martin, Peter; Goodyer, Ian M; Wilkinson, Paul; Consortium, Impact; Midgley, Nick

    2017-10-30

    Therapy dropout is a common occurrence, especially in adolescence. This study investigated whether dropout could be predicted from a range of child, family, and treatment factors in a sample of adolescents receiving therapy for depression. This study draws on data from 406 participants of the IMPACT study, a randomized controlled trial, investigating three types of therapy in the treatment of adolescent depression. Logistic regression was used to estimate the effects of predictors on the odds of dropout. Few pre-treatment predictors of dropout were found, with the only significant predictors being older age, antisocial behaviour, and lower scores of verbal intelligence. Missed sessions and poorer therapeutic alliance early in treatment also predicted dropout. Most child and family factors investigated were not significantly associated with dropout. There may be little about depressed adolescents' presentation prior to therapy starting that indicates their risk of dropout. However, within-treatment factors indicated that warning signs of dropout may be identifiable during the initial phase of therapy. Identifying and targeting early treatment indicators of dropout may provide possibilities for improving engagement. Clinical and methodological significance of this article: In the literature, a great deal of attention has been paid to child and family factors that predict therapy dropout, yet in this study, few pre-treatment characteristics were predictive of dropout. However, findings revealed possible warning signs of dropout in the early part of treatment, as poor therapeutic alliance and missed sessions were both found to be predictive of dropout. These findings call for therapists to be aware of such warning signs and clinical guidelines for managing cases at risk of dropout are warranted.

  14. Can Social-Emotional Learning Reduce School Dropout in Developing Countries?

    Science.gov (United States)

    Wang, Huan; Chu, James; Loyalka, Prashant; Xin, Tao; Shi, Yaojiang; Qu, Qinghe; Yang, Chu

    2016-01-01

    An alarming number of students drop out of junior high school in developing countries. In this study, we examine the impacts of providing a social-emotional learning (SEL) program on the dropout behavior and learning anxiety of students in the first two years of junior high. We do so by analyzing data from a randomized controlled trial involving…

  15. Stress and hazardous alcohol use: associations with early dropout from university.

    Science.gov (United States)

    Andersson, Claes; Johnsson, Kent O; Berglund, Mats; Ojehagen, Agneta

    2009-09-01

    The transition to studying at university is associated with increased levels of both stress and hazardous alcohol use. The aim of this study is to investigate the influence of these factors on first-year dropout from university studies. Two complete cohorts of university freshmen at two homogeneous universities, one in the north and one in the south of Sweden, were asked to participate in an intervention study. Participants responded to a baseline questionnaire including measures of stress and alcohol use. Official university records showing dropout over 12 months were collected. A multivariate analysis established that high stress and admission to the northern university were associated with dropout from university studies, while symptoms of depression and anxiety as well as hazardous drinking were not. There is a need to address the issue of stress associated with the start of university studies. It seems important to offer stress-reducing interventions, specifically aimed at reducing transitional stress, as soon as students start university.

  16. Huff 'n puff to revaporize liquid dropout in an Omani gas field

    Energy Technology Data Exchange (ETDEWEB)

    Al-Wadhahi, M.; Boukadi, F.H.; Al-Bemani, A.; Al-Maamari, R.; Al-Hadrami, H. [Department of Petroleum and Chemical Engineering, Sultan Qaboos University, P.O. Box 33, Al-Khod 123 (Oman)

    2007-01-15

    In this study, Huff 'n Puff technique is used as a production mechanism to revaporize liquid dropout in the Saih Rawl retrograde condensate gas field, Oman. During the huff cycle, a number of wells were shut in to achieve revaporization. The same wells were put on stream, during the puff cycle. Liquid dropout induced a mechanical skin around the wellbore and hampered gas production capabilities but has been revaporized through pressurization. The pressure buildup in the rich-gas condensate reservoir was due to a cross flow originating from a deeper highly pressurized lean-gas bearing formation. The pressure communication was taking place through the wellbore during shut-in cycles. A compositional simulation model was used to confirm the theory of condensate revaporization. Simulation results indicated that Huff 'n Puff is a viable production technique. The technique improved gas deliverability and enhanced gas-liquid production by minimizing the skin caused by gas-liquid dropout. (author)

  17. HIGH-RATE DISINFECTION TECHNIQUES FOR COMBIND SEWER OVERFLOW

    Science.gov (United States)

    This paper presents high-rate disinfection technologies for combined sewer overflow (CSO). The high-rate disinfection technologies of interest are: chlorination/dechlorination, ultraviolet light irradiation (UV), chlorine dioxide (ClO2 ), ozone (O3), peracetic acid (CH3COOOH )...

  18. High Graduate Unemployment Rate and Taiwanese Undergraduate Education

    Science.gov (United States)

    Wu, Chih-Chun

    2011-01-01

    An expansion in higher education in combination with the recent global economic recession has resulted in a high college graduate unemployment rate in Taiwan. This study investigates how the high unemployment rate and financial constraints caused by economic cutbacks have shaped undergraduates' class choices, job needs, and future income…

  19. Circuit and interconnect design for high bit-rate applications

    NARCIS (Netherlands)

    Veenstra, H.

    2006-01-01

    This thesis presents circuit and interconnect design techniques and design flows that address the most difficult and ill-defined aspects of the design of ICs for high bit-rate applications. Bottlenecks in interconnect design, circuit design and on-chip signal distribution for high bit-rate

  20. Reasons for dropout in swimmers, differences between gender and age and intentions to return to competition.

    Science.gov (United States)

    Monteiro, Diogo M; Marinho, Daniel A; Moutão, João M; Vitorino, Anabela P; Antunes, Raúl N; Cid, Luís

    2018-01-01

    This study's main purpose was to analyze reasons for dropout in competitive swimmers and differences between gender and age groups. The influence of dropout on swimmers intentions to return to competition, invariance across gender and validation of Questionnaire of Reasons for Attrition were also analyzed. Study 1 - 366 athletes participated (N.=366; mean age 15.96, SD 5.99) and the data gathered was used for the exploratory analysis, and data gathered on 1008 athletes were used for the confirmatory analysis and the structural equations (N.=1008; mean age 16.26, SD 6.12); Study 2: 1008 athletes participated (N.=1008; mean age 16.26, SD 6.12) on the descriptive and inferential analysis of the reasons behind the practice dropout. The Questionnaire of Reasons Attrition was used in both studies to assess the reasons associated with the practice dropout. In study 1, the results showed an acceptable fit of the measurement model and invariance across gender and also predictive validity regarding swimmers intentions to return to competition (e.g., "demands/pressure" negatively predict intentions). In study 2, the main results showed that the most significant reason for dropout in both genders and all age groups was "dissatisfaction/other priorities"; the study also showed there to be differences between gender and age groups (e.g., female and younger athletes valued "demands/ pressure "more). This study offers useful guidelines for the training process and to support decisions on sports politics to be implemented to overcome the dropout rate. However, it is important to broaden the evidence to other sports and implement programs on identified priority areas based on longitudinal perspectives.

  1. Predictors of dropout in the German disease management program for type 2 diabetes.

    Science.gov (United States)

    Fullerton, Birgit; Erler, Antje; Pöhlmann, Boris; Gerlach, Ferdinand M

    2012-01-10

    To improve and assess the effectiveness of disease management programs (DMPs), it is critical to understand how many people drop out of disease management programs and why. We used routine data provided by a statutory health insurance fund from the regions North Rhine, North Wurttemberg and Hesse. As part of the German DMP for type 2 diabetes, the insurance fund received regular documentation of all members participating in the program. We followed 10,989 patients who enrolled in the DMP between July 2004 and December 2005 until the end of 2007 to study how many patients dropped out of the program. Dropout was defined based on the discontinuation of program documentation on a particular patient, excluding situations in which the patient died or left the insurance fund. Predictors of dropout, assessed at the time of program enrolment, were explored using logistic regression analysis. 5.5% of the patients dropped out of the disease management program within the observation period. Predictors of dropout at the time of enrolment were: region; retirement status; the number of secondary diseases; presence of a disabling secondary disease; doctor's recommendations to stop smoking or to seek nutritional counselling; and the completion and outcome of the routine foot and eye exams. Different trends of dropout were observed among retired and employed patients: retired patients of old age, who possibly drop out of the program due to other health care priorities and employed people of younger age who have not yet developed many secondary diseases, but were recommended to change their lifestyle. Overall, dropout rates for the German disease management programs for type 2 diabetes were low compared to other studies. Factors assessed at the time of program enrolment were predictive of later dropout and should be further studied to provide information for future program improvements.

  2. Introduction to State Estimation of High-Rate System Dynamics.

    Science.gov (United States)

    Hong, Jonathan; Laflamme, Simon; Dodson, Jacob; Joyce, Bryan

    2018-01-13

    Engineering systems experiencing high-rate dynamic events, including airbags, debris detection, and active blast protection systems, could benefit from real-time observability for enhanced performance. However, the task of high-rate state estimation is challenging, in particular for real-time applications where the rate of the observer's convergence needs to be in the microsecond range. This paper identifies the challenges of state estimation of high-rate systems and discusses the fundamental characteristics of high-rate systems. A survey of applications and methods for estimators that have the potential to produce accurate estimations for a complex system experiencing highly dynamic events is presented. It is argued that adaptive observers are important to this research. In particular, adaptive data-driven observers are advantageous due to their adaptability and lack of dependence on the system model.

  3. Processing of high-temperature superconductors at high strain rates

    International Nuclear Information System (INIS)

    Mamalis, A.G.; Pantazsopoulos, G.; Manolakos, D.E.; Szalay, A.

    2000-01-01

    This new book provides, for the first time, a systematic, unified presentation of all steps in the processing of high-temperature superconductor materials, ranging from synthesis of various systems to fabrication and industrial applications. Also covered are characterization techniques and current directions in research and development. The authors are leading specialists who bring to this new book their many years of experience in research, education and industrial engineering work in superconductor materials. This book is primarily focused on the bulk-fabrication techniques of high-temperature ceramic superconducting components, especially on the combination of dynamic powder-consolidation and subsequent deformation processing. The properties of these ceramics, which are difficult-to-form materials by applying conventional techniques, are combined for the net-shape manufacturing of such components for the construction of HTS deviceshor e llipsis. However, very important topics such as superconducting structures, chemical synthesis, film fabrication and characterization techniques are also reviewedhor e llipsis to provide a complete, comprehensive view of superconductors engineering

  4. High dose rate brachytherapy in treatment of high grade astrocytomas

    International Nuclear Information System (INIS)

    Garcia-Alejo, R.; Delgado, J.M.; Cerro, E. del; Torres, J.J.; Martinez, R.

    1996-01-01

    From May 1994 to June 1995, 18 patients with high grade astrocytomas were entered prospectively on a selective protocol combining surgery, external beam radiotherapy, stereotactic interstitial implantation with HDR Iridium 192 and chemotherapy. Only those patients with tumor size 100cc or less average dimension, high grade astrocytoma, Karnofsky 70 or greater, unilateral, circumscribed, unifocal, tumor stable or responding to external radiation and supratentorial were included in the study. Ages ranged from 16 to 69 years. There were 13 males and 5 females. Surgery consisted of biopsy only in 3 patients, subtotal resection in 11, and gross total resection in 4 patients. Focal external beam radiation portals included the contrast enhancing mass on CT scan plus a 3 cm margin. The protocol called for minimum tumor dose of 60 Gy to be given in 2 Gy daily fractions. An interstitial brachytherapy boost was to be performed two weeks after the conclusion of external beam radiation. The dose was 30 Gy in 4 fractions. The authors analyze on basis on their personal experience, the possibilities and the limits offered by this therapeutic procedure in neuro-oncology. Using stereotactic techniques, interstitial brachytherapy of brain tumors was technically possible with negligible acute morbidity and mortality, and appeared to be effective and may provide for an increase in tumor control in selected cases

  5. Predictors of Dropout by Female Obese Patients Treated with a Group Cognitive Behavioral Therapy to Promote Weight Loss

    Directory of Open Access Journals (Sweden)

    Ryoko Sawamoto

    2016-01-01

    Full Text Available Objective: To investigate predictors of dropout from a group cognitive behavioral therapy (CBT intervention for overweight or obese women. Methods: 119 overweight and obese Japanese women aged 25-65 years who attended an outpatient weight loss intervention were followed throughout the 7-month weight loss phase. Somatic characteristics, socioeconomic status, obesity-related diseases, diet and exercise habits, and psychological variables (depression, anxiety, self-esteem, alexithymia, parenting style, perfectionism, and eating attitude were assessed at baseline. Significant variables, extracted by univariate statistical analysis, were then used as independent variables in a stepwise multiple logistic regression analysis with dropout as the dependent variable. Results: 90 participants completed the weight loss phase, giving a dropout rate of 24.4%. The multiple logistic regression analysis demonstrated that compared to completers the dropouts had significantly stronger body shape concern, tended to not have jobs, perceived their mothers to be less caring, and were more disorganized in temperament. Of all these factors, the best predictor of dropout was shape concern. Conclusion: Shape concern, job condition, parenting care, and organization predicted dropout from the group CBT weight loss intervention for overweight or obese Japanese women.

  6. Psychosocial risk and protective factors of secondary school dropout in Luxembourg: the protocol of an exploratory case-control study.

    Science.gov (United States)

    Esch, Pascale; Bocquet, Valéry; Pull, Charles; Couffignal, Sophie; Graas, Marc; Lair, Marie-Lise; Lehnert, Torsten; Fond-Harmant, Laurence; Ansseau, Marc

    2011-07-13

    In Luxembourg, the extensive phenomenon of school dropout is a prime policy concern in the light of individual, social and economic consequences. Although the authorities report an overall decrease of the national dropout rate, the proportion of early school leavers who remain without any specific occupation is still alarming. Therefore, this study intends a shift of focus from system-inherent to individual factors, including mental health and family correlates, to provide a more comprehensive analysis of the dropout phenomenon. The objectives of this study are to investigate the type and prevalence of psychiatric disorders among school dropouts and to compare the findings with those by a matched control group of regularly enrolled students. Furthermore, family variables and socioeconomic status will be analysed, as they are factors likely to interfere with both educational attainment and mental health. A trained psychologist will use structured interviews and self-report forms to investigate for mental health issues, information on schooling, socioeconomic situation and family life. Controls will be matched for gender, age, school type and educational grade. As school dropouts face a serious risk of long term professional and social marginalization, there is an evident need for action. Identifying psychosocial risk and protective factors of school dropout will deliver solid insight on how to conceive public health strategies for young people who may need a more customized support to carry out their academic potential. ClinicalTrials.gov Identifier: NCT01354236.

  7. Predictors of Dropout by Female Obese Patients Treated with a Group Cognitive Behavioral Therapy to Promote Weight Loss.

    Science.gov (United States)

    Sawamoto, Ryoko; Nozaki, Takehiro; Furukawa, Tomokazu; Tanahashi, Tokusei; Morita, Chihiro; Hata, Tomokazu; Komaki, Gen; Sudo, Nobuyuki

    2016-01-01

    To investigate predictors of dropout from a group cognitive behavioral therapy (CBT) intervention for overweight or obese women. 119 overweight and obese Japanese women aged 25-65 years who attended an outpatient weight loss intervention were followed throughout the 7-month weight loss phase. Somatic characteristics, socioeconomic status, obesity-related diseases, diet and exercise habits, and psychological variables (depression, anxiety, self-esteem, alexithymia, parenting style, perfectionism, and eating attitude) were assessed at baseline. Significant variables, extracted by univariate statistical analysis, were then used as independent variables in a stepwise multiple logistic regression analysis with dropout as the dependent variable. 90 participants completed the weight loss phase, giving a dropout rate of 24.4%. The multiple logistic regression analysis demonstrated that compared to completers the dropouts had significantly stronger body shape concern, tended to not have jobs, perceived their mothers to be less caring, and were more disorganized in temperament. Of all these factors, the best predictor of dropout was shape concern. Shape concern, job condition, parenting care, and organization predicted dropout from the group CBT weight loss intervention for overweight or obese Japanese women. © 2016 S. Karger GmbH, Freiburg.

  8. Baseline participant characteristics and risk for dropout from ten obesity randomized controlled trials: a pooled analysis of individual level data.

    Science.gov (United States)

    Kaiser, Kathryn A; Affuso, Olivia; Desmond, Renee; Allison, David B

    Understanding participant demographic characteristics that inform the optimal design of obesity RCTs have been examined in few studies. The objective of this study was to investigate the association of individual participant characteristics and dropout rates (DORs) in obesity randomized controlled trials (RCT) by pooling data from several publicly available datasets for analyses. We comprehensively characterize DORs and patterns in obesity RCTs at the individual study level, and describe how such rates and patterns vary as a function of individual-level characteristics. We obtained and analyzed nine publicly-available, obesity RCT datasets that examined weight loss or weight gain prevention as a primary or secondary endpoint. Four risk factors for dropout were examined by Cox proportional hazards including sex, age, baseline BMI, and race/ethnicity. The individual study data were pooled in the final analyses with a random effect for study, and HR and 95% CIs were computed. Results of the multivariate analysis indicated that the risk of dropout was significantly higher for females compared to males (HR= 1.24, 95% CI = 1.05, 1.46). Hispanics and Non-Hispanic blacks had a significantly higher dropout rate compared to non-Hispanic whites (HR= 1.62, 95% CI = 1.37, 1.91; HR= 1.22, 95% CI = 1.11, 1.35, respectively). There was a significantly increased risk of dropout associated with advancing age (HR= 1.02, 95% CI = 1.01, 1.02) and increasing BMI (HR= 1.03, 95% CI = 1.03, 1.04). As more studies may focus on special populations, researchers designing obesity RCTs may wish to oversample in certain demographic groups if attempting to match comparison groups based on generalized estimates of expected dropout rates, or otherwise adjust a priori power estimates. Understanding true reasons for dropout may require additional methods of data gathering not generally employed in obesity RCTs, e.g. time on treatment.

  9. Identifying potential dropouts from college physics classes

    Science.gov (United States)

    Wollman, Warren; Lawrenz, Frances

    Hudson and Rottman (1981) established that mathematics ability is probably a secondary factor influencing dropout from college physics courses. Other factors remain to be found for predicting who will drop out or at least have difficulty with the course. When mathematics ability is coupled with general indicators of performance (total GPA and ACT natural science), prediction of performance for those who complete the course is substantially improved. Moreover, discriminant analyses reveal who will have at least some difficulty, but not who will drop out. The problem of isolating specific weaknesses of students who have difficulty persists. Physics achievement appears to depend on mathematics ability only to the extent that students possess the ability to utilize mathematics knowledge for solving physics problems. Identification of the specific aspects of this ability as well as the specific deficiencies leading to dropout should be the object of future research. For the present, interviews might be more revealing than group testing methods.

  10. Quantum data locking for high-rate private communication

    International Nuclear Information System (INIS)

    Lupo, Cosmo; Lloyd, Seth

    2015-01-01

    We show that, if the accessible information is used as a security quantifier, quantum channels with a certain symmetry can convey private messages at a tremendously high rate, as high as less than one bit below the rate of non-private classical communication. This result is obtained by exploiting the quantum data locking effect. The price to pay to achieve such a high private communication rate is that accessible information security is in general not composable. However, composable security holds against an eavesdropper who is forced to measure her share of the quantum system within a finite time after she gets it. (paper)

  11. Effectiveness of high interest rate policy on exchange rates: A reexamination of the Asian financial crisis

    Directory of Open Access Journals (Sweden)

    Chin Diew Lai

    2006-09-01

    Full Text Available One of the most controversial issues in the aftermath of the Asian financial crisis has been the appropriate response of monetary policy to a sharp decline in the value of some currencies. In this paper, we empirically examine the effects on Asian exchange rates of sharply higher interest rates during the Asian financial crisis. Taking account of the currency contagion effect, our results indicate that sharply higher interest rates helped to support the exchange rates of South Korea, the Philippines, and Thailand. For Malaysia, no significant causal relation is found from the rate of interest to exchange rates, as the authorities in Malaysia did not actively adopt a high interest rate policy to defend the currency.

  12. Is Obesity Associated with School Dropout? Key Developmental and Ethnic Differences

    Science.gov (United States)

    Lanza, H. Isabella; Huang, David Y. C.

    2015-01-01

    Background: We aimed to expand the literature on child obesity and school outcomes by examining associations between obesity and high school dropout, including the role of obesity onset and duration as well as ethnicity. Methods: Data on 5066 children obtained between 1986 and 2010 from the child cohort of the 1979 National Longitudinal Study of…

  13. Comparing Dropout Predictors for Two State-Level Panels Using Grade 6 and Grade 8 Data

    Science.gov (United States)

    Franklin, Bobby J.; Trouard, Stephen B.

    2016-01-01

    The purpose of this study was to examine the effectiveness of dropout predictors across time. Two state-level high school graduation panels were selected to begin with the seventh and ninth grades but end at the same time. The first panel (seventh grade) contained 29,554 students and used sixth grade predictors. The second panel (ninth grade)…

  14. A Meta-Analysis of Dropout Prevention Outcomes and Strategies. A Technical Report

    Science.gov (United States)

    Chappell, Shanan L.; O'Connor, Patrick; Withington, Cairen; Stegelin, Dolores A.

    2015-01-01

    Almost from the start of the public schools system in America, students have been leaving school without high school diplomas. However, the dropout issue did not rise to the level of significance it has today until the early 1980s, when social pressures, along with business leaders, leveraged their influence on educators to address the dropout…

  15. Advancing the "Colorado Graduates" Agenda: Understanding the Dropout Problem and Mobilizing to Meet the Graduation Challenge

    Science.gov (United States)

    Mac Iver, Martha Abele; Balfanz, Robert; Byrnes, Vaughan

    2009-01-01

    The ambitious goal set by Colorado's governor to address the state's dropout problem is a model for the nation. Helping thousands of young people to receive their high school diplomas instead of leaving school without them is a crucial step in improving the quality of life for all Colorado residents. Accomplishing this goal will require focused…

  16. Grad Nation: A Guidebook to Help Communities Tackle the Dropout Crisis

    Science.gov (United States)

    Balfanz, Robert; Fox, Joanna Hornig; Bridgeland, John M.; McNaught, Mary

    2009-01-01

    With more than one million students dropping out of high school each year, Grad Nation is specifically designed to offer solutions and tools for every size community and presents a compelling case for all sectors of society to get involved. The guidebook is part of the Alliance's Dropout Prevention Campaign. The guide brings together the nation's…

  17. Effect of high heating rate on thermal decomposition behaviour of ...

    Indian Academy of Sciences (India)

    the thermal decomposition behaviour of the aforementioned powder at high heating rates was taken into considera- ... does not change the process of releasing hydrogen from titanium hydride ... from titanium hydride in a sequence of steps.

  18. Treatment of the prostate cancer with high dose rate brachytherapy

    International Nuclear Information System (INIS)

    Martinez, Alvaro; Torres Silva, Felipe

    2002-01-01

    The prostate cancer treatment in early stages is controversial. The high dose rate brachytherapy has been used like monotherapy or boost with external beam radiotherapy in advanced disease. This paper describes the technique and the advantages over other modalities

  19. Effect of high heating rate on thermal decomposition behaviour of ...

    Indian Academy of Sciences (India)

    Effect of high heating rate on thermal decomposition behaviour of titanium hydride ... hydride powder, while switching it from internal diffusion to chemical reaction. ... TiH phase and oxides form on the powder surface, controlling the process.

  20. Increased strength of concrete subject to high loading rates

    International Nuclear Information System (INIS)

    Curbach, M.

    1987-01-01

    Within the scope of this work various problems are discussed which occur in connection with concrete under high tensile loading rates (e.g. when a plane crashes on a nuclear power plant very high loads occur which act only for a very short time). Particularly the causes for the already frequently noticed increases in strength with increasing loading rates are investigated and also the question whether this increased strength can be taken into account when dimensioning a construction. (MM) [de

  1. Quantum Communication with a High-Rate Entangled Photon Source

    Science.gov (United States)

    Wilson, Nathaniel C.; Chaffee, Dalton W.; Lekki, John D.; Wilson, Jeffrey D.

    2016-01-01

    A high generation rate photon-pair source using a dual element periodically-poled potassium titanyl phosphate (PP KTP) waveguide is described. The photon-pair source features a high pair generation rate, a compact power-efficient package, and continuous wave (CW) or pulsed operation. Characterization and test results are presented. Details and preliminary results of a laboratory free-space QKD experiment with the B92 protocol are also presented.

  2. 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%…

  3. Ethnic Minority Dropout in Economics

    Science.gov (United States)

    Arnold, Ivo J. M.

    2013-01-01

    This paper investigates the first-year study success of minority students in the bachelor program in economics at Erasmus University Rotterdam. We find that the gap in study success between minority and majority students can be attributed to differences in high school education. Students from similar high school tracks show no significant…

  4. Allelic drop-out probabilities estimated by logistic regression

    DEFF Research Database (Denmark)

    Tvedebrink, Torben; Eriksen, Poul Svante; Asplund, Maria

    2012-01-01

    We discuss the model for estimating drop-out probabilities presented by Tvedebrink et al. [7] and the concerns, that have been raised. The criticism of the model has demonstrated that the model is not perfect. However, the model is very useful for advanced forensic genetic work, where allelic drop-out...... is occurring. With this discussion, we hope to improve the drop-out model, so that it can be used for practical forensic genetics and stimulate further discussions. We discuss how to estimate drop-out probabilities when using a varying number of PCR cycles and other experimental conditions....

  5. High Heating Rates Affect Greatly the Inactivation Rate of Escherichia coli

    Science.gov (United States)

    Huertas, Juan-Pablo; Aznar, Arantxa; Esnoz, Arturo; Fernández, Pablo S.; Iguaz, Asunción; Periago, Paula M.; Palop, Alfredo

    2016-01-01

    Heat resistance of microorganisms can be affected by different influencing factors. Although, the effect of heating rates has been scarcely explored by the scientific community, recent researches have unraveled its important effect on the thermal resistance of different species of vegetative bacteria. Typically heating rates described in the literature ranged from 1 to 20°C/min but the impact of much higher heating rates is unclear. The aim of this research was to explore the effect of different heating rates, such as those currently achieved in the heat exchangers used in the food industry, on the heat resistance of Escherichia coli. A pilot plant tubular heat exchanger and a thermoresistometer Mastia were used for this purpose. Results showed that fast heating rates had a deep impact on the thermal resistance of E. coli. Heating rates between 20 and 50°C/min were achieved in the heat exchanger, which were much slower than those around 20°C/s achieved in the thermoresistometer. In all cases, these high heating rates led to higher inactivation than expected: in the heat exchanger, for all the experiments performed, when the observed inactivation had reached about seven log cycles, the predictions estimated about 1 log cycle of inactivation; in the thermoresistometer these differences between observed and predicted values were even more than 10 times higher, from 4.07 log cycles observed to 0.34 predicted at a flow rate of 70 mL/min and a maximum heating rate of 14.7°C/s. A quantification of the impact of the heating rates on the level of inactivation achieved was established. These results point out the important effect that the heating rate has on the thermal resistance of E. coli, with high heating rates resulting in an additional sensitization to heat and therefore an effective food safety strategy in terms of food processing. PMID:27563300

  6. Stretching of red blood cells at high strain rates

    Science.gov (United States)

    Mancuso, J. E.; Ristenpart, W. D.

    2017-10-01

    Most work on the mechanical behavior of red blood cells (RBCs) in flow has focused on simple shear flows. Relatively little work has examined RBC deformations in the physiologically important extensional flow that occurs at the entrance to a constriction. In particular, previous work suggests that RBCs rapidly stretch out and then retract upon entering the constriction, but to date no model predicts this behavior for the extremely high strain rates typically experienced there. In this Rapid Communication, we use high speed video to perform systematic measurements of the dynamic stretching behavior of RBCs as they enter a microfluidic constriction. We demonstrate that both the Kelvin-Voigt and Skalak viscoelastic models capture the observed stretching dynamics, up to strain rates as high as 2000 s-1. The results indicate that the effective elastic modulus of the RBC membrane at these strain rates is an order of magnitude larger than moduli measured by micropipette aspiration or other low strain rate techniques.

  7. Factors associated with dropout in a long term observational cohort of fishing communities around lake Victoria, Uganda.

    Science.gov (United States)

    Abaasa, Andrew; Asiki, Gershim; Mpendo, Juliet; Levin, Jonathan; Seeley, Janet; Nielsen, Leslie; Ssetaala, Ali; Nanvubya, Annet; De Bont, Jan; Kaleebu, Pontiano; Kamali, Anatoli

    2015-12-24

    Fishing communities are potentially suitable for Human immunodeficiency virus (HIV) efficacy trials due to their high risk profile. However, high mobility and attrition could decrease statistical power to detect the impact of a given intervention. We report dropout and associated factors in a fisher-folk observational cohort in Uganda. Human immunodeficiency virus-uninfected high-risk volunteers aged 13-49 years living in five fishing communities around Lake Victoria were enrolled and followed every 6 months for 18 months at clinics located within each community. Volunteers from two of the five communities had their follow-up periods extended to 30 months and were invited to attend clinics 10-40 km (km) away from their communities. Human immunodeficiency virus counseling and testing was provided, and data on sexual behaviour collected at all study visits. Study completion was defined as completion of 18 or 30 months or visits up to the date of sero-conversion and dropout as missing one or more visits. Discrete time survival models were fitted to find factors independently associated with dropout. A total of 1000 volunteers (55% men) were enrolled. Of these, 91.9% completed 6 months, 85.2% completed 12 months and 76.0% completed 18 months of follow-up. In the two communities with additional follow-up, 76.9% completed 30 months. In total 299 (29.9%) volunteers missed at least one visit (dropped out). Dropout was independently associated with age (volunteers aged 13-24 being most likely to dropout), gender [men being more likely to dropout than women [adjusted hazard ratio (aHR) 1.4; 95% confidence interval (CI) 1.1-1.8)], time spent in the fishing community (those who stayed dropout), History of marijuana use (users being more likely to dropout than non-users [1.7; (1.2-2.5)], ethnicity (non-Baganda being more likely to dropout than Baganda [1.5; (1.2-1.9)], dropout varied between the five fishing communities, having a new sexual partner in the previous 3 months [1

  8. Solidification at the High and Low Rate Extreme

    Energy Technology Data Exchange (ETDEWEB)

    Meco, Halim [Iowa State Univ., Ames, IA (United States)

    2004-12-19

    The microstructures formed upon solidification are strongly influenced by the imposed growth rates on an alloy system. Depending on the characteristics of the solidification process, a wide range of growth rates is accessible. The prevailing solidification mechanisms, and thus the final microstructure of the alloy, are governed by these imposed growth rates. At the high rate extreme, for instance, one can have access to novel microstructures that are unattainable at low growth rates. While the low growth rates can be utilized for the study of the intrinsic growth behavior of a certain phase growing from the melt. Although the length scales associated with certain processes, such as capillarity, and the diffusion of heat and solute, are different at low and high rate extremes, the phenomena that govern the selection of a certain microstructural length scale or a growth mode are the same. Consequently, one can analyze the solidification phenomena at both high and low rates by using the same governing principles. In this study, we examined the microstructural control at both low and high extremes. For the high rate extreme, the formation of crystalline products and factors that control the microstructure during rapid solidification by free-jet melt spinning are examined in Fe-Si-B system. Particular attention was given to the behavior of the melt pool at different quench-wheel speeds. Since the solidification process takes place within the melt-pool that forms on the rotating quench-wheel, we examined the influence of melt-pool dynamics on nucleation and growth of crystalline solidification products and glass formation. High-speed imaging of the melt-pool, analysis of ribbon microstructure, and measurement of ribbon geometry and surface character all indicate upper and lower limits for melt-spinning rates for which nucleation can be avoided, and fully amorphous ribbons can be achieved. Comparison of the relevant time scales reveals that surface-controlled melt

  9. Pedalling rate affects endurance performance during high-intensity cycling

    DEFF Research Database (Denmark)

    Nielsen, Jens Steen; Hansen, Ernst Albin; Sjøgaard, Gisela

    2004-01-01

    The purpose of this study into high-intensity cycling was to: (1) test the hypothesis that endurance time is longest at a freely chosen pedalling rate (FCPR), compared to pedalling rates 25% lower (FCPR-25) and higher (FCPR+25) than FCPR, and (2) investigate how physiological variables......, and endurance time at W90 with FCPR-25, FCPR, and FCPR+25. Power reserve was calculated as the difference between applied power output at a given pedalling rate and peak crank power at this same pedalling rate. W90 was 325 (47) W. FCPR at W90 was 78 (11) rpm, resulting in FCPR-25 being 59 (8) rpm and FCPR+25...... time was negatively related to VO(2max), W90 and % MHC I, while positively related to power reserve. In conclusion, at group level, endurance time was longer at FCPR and at a pedalling rate 25% lower compared to a pedalling rate 25% higher than FCPR. Further, inter-individual physiological variables...

  10. Decay rate of the false vacuum at high temperatures

    International Nuclear Information System (INIS)

    Eboli, O.J.P.; Marques, G.C.

    1986-01-01

    We investigate, within the semiclassical approach, the high temperature behaviour of the decay rate (Γ) of the metastable vacuum in Field Theory. We exhibit some exactly soluble (1+1) and (3+1) dimensional examples and develop a formal expression for γ in the high temperature limit. (Author) [pt

  11. "Meta-Analysis of Dropout in Treatments for Posttraumatic Stress Disorder": Correction to Imel et al. (2013).

    Science.gov (United States)

    2016-09-01

    Reports an error in "Meta-analysis of dropout in treatments for posttraumatic stress disorder" by Zac E. Imel, Kevin Laska, Matthew Jakupcak and Tracy L. Simpson ( Journal of Consulting and Clinical Psychology , 2013[Jun], Vol 81[3], 394-404). There are two errors in the Results section. Each is described alongside the corrected results. Corrections did not influence interpretation of the results. Neither the magnitude of effects nor statistical significance of any results is substantively altered. (The following abstract of the original article appeared in record 2013-01522-001.) Objective: Many patients drop out of treatments for posttraumatic stress disorder (PTSD); some clinicians believe that trauma-focused treatments increase dropout. We conducted a meta-analysis of dropout among active treatments in clinical trials for PTSD (42 studies; 17 direct comparisons). The average dropout rate was 18%, but it varied significantly across studies. Group modality and greater number of sessions, but not trauma focus, predicted increased dropout. When the meta-analysis was restricted to direct comparisons of active treatments, there were no differences in dropout. Differences in trauma focus between treatments in the same study did not predict dropout. However, trauma-focused treatments resulted in higher dropout compared with present-centered therapy (PCT), a treatment originally designed as a control but now listed as a research-supported intervention for PTSD. Dropout varies between active interventions for PTSD across studies, but variability is primarily driven by differences between studies. There do not appear to be systematic differences across active interventions when they are directly compared in the same study. The degree of clinical attention placed on the traumatic event does not appear to be a primary cause of dropout from active treatments. However, comparisons of PCT may be an exception to this general pattern, perhaps because of a restriction of

  12. High-repetition-rate short-pulse gas discharge.

    Science.gov (United States)

    Tulip, J; Seguin, H; Mace, P N

    1979-09-01

    A high-average-power short-pulse gas discharge is described. This consists of a volume-preionized transverse discharge of the type used in gas lasers driven by a Blumlein energy storage circuit. The Blumlein circuit is fabricated from coaxial cable, is pulse-charged from a high-repetition-rate Marx-bank generator, and is switched by a high-repetition-rate segmented rail gap. The operation of this discharge under conditions typical of rare-gas halide lasers is described. A maximum of 900 pps was obtained, giving a power flow into the discharge of 30 kW.

  13. Ethnic minority dropout in economics

    NARCIS (Netherlands)

    Arnold, I.J.M.

    2013-01-01

    This paper investigates the first-year study success of minority students in the bachelor program in economics at Erasmus University Rotterdam. We find that the gap in study success between minority and majority students can be attributed to differences in high school education. Students from

  14. Evolution of high tooth replacement rates in sauropod dinosaurs.

    Science.gov (United States)

    D'Emic, Michael D; Whitlock, John A; Smith, Kathlyn M; Fisher, Daniel C; Wilson, Jeffrey A

    2013-01-01

    Tooth replacement rate can be calculated in extinct animals by counting incremental lines of deposition in tooth dentin. Calculating this rate in several taxa allows for the study of the evolution of tooth replacement rate. Sauropod dinosaurs, the largest terrestrial animals that ever evolved, exhibited a diversity of tooth sizes and shapes, but little is known about their tooth replacement rates. We present tooth replacement rate, formation time, crown volume, total dentition volume, and enamel thickness for two coexisting but distantly related and morphologically disparate sauropod dinosaurs Camarasaurus and Diplodocus. Individual tooth formation time was determined by counting daily incremental lines in dentin. Tooth replacement rate is calculated as the difference between the number of days recorded in successive replacement teeth. Each tooth family in Camarasaurus has a maximum of three replacement teeth, whereas each Diplodocus tooth family has up to five. Tooth formation times are about 1.7 times longer in Camarasaurus than in Diplodocus (315 vs. 185 days). Average tooth replacement rate in Camarasaurus is about one tooth every 62 days versus about one tooth every 35 days in Diplodocus. Despite slower tooth replacement rates in Camarasaurus, the volumetric rate of Camarasaurus tooth replacement is 10 times faster than in Diplodocus because of its substantially greater tooth volumes. A novel method to estimate replacement rate was developed and applied to several other sauropodomorphs that we were not able to thin section. Differences in tooth replacement rate among sauropodomorphs likely reflect disparate feeding strategies and/or food choices, which would have facilitated the coexistence of these gigantic herbivores in one ecosystem. Early neosauropods are characterized by high tooth replacement rates (despite their large tooth size), and derived titanosaurs and diplodocoids independently evolved the highest known tooth replacement rates among archosaurs.

  15. Evolution of high tooth replacement rates in sauropod dinosaurs.

    Directory of Open Access Journals (Sweden)

    Michael D D'Emic

    Full Text Available BACKGROUND: Tooth replacement rate can be calculated in extinct animals by counting incremental lines of deposition in tooth dentin. Calculating this rate in several taxa allows for the study of the evolution of tooth replacement rate. Sauropod dinosaurs, the largest terrestrial animals that ever evolved, exhibited a diversity of tooth sizes and shapes, but little is known about their tooth replacement rates. METHODOLOGY/PRINCIPAL FINDINGS: We present tooth replacement rate, formation time, crown volume, total dentition volume, and enamel thickness for two coexisting but distantly related and morphologically disparate sauropod dinosaurs Camarasaurus and Diplodocus. Individual tooth formation time was determined by counting daily incremental lines in dentin. Tooth replacement rate is calculated as the difference between the number of days recorded in successive replacement teeth. Each tooth family in Camarasaurus has a maximum of three replacement teeth, whereas each Diplodocus tooth family has up to five. Tooth formation times are about 1.7 times longer in Camarasaurus than in Diplodocus (315 vs. 185 days. Average tooth replacement rate in Camarasaurus is about one tooth every 62 days versus about one tooth every 35 days in Diplodocus. Despite slower tooth replacement rates in Camarasaurus, the volumetric rate of Camarasaurus tooth replacement is 10 times faster than in Diplodocus because of its substantially greater tooth volumes. A novel method to estimate replacement rate was developed and applied to several other sauropodomorphs that we were not able to thin section. CONCLUSIONS/SIGNIFICANCE: Differences in tooth replacement rate among sauropodomorphs likely reflect disparate feeding strategies and/or food choices, which would have facilitated the coexistence of these gigantic herbivores in one ecosystem. Early neosauropods are characterized by high tooth replacement rates (despite their large tooth size, and derived titanosaurs and

  16. Low dose rate and high dose rate intracavitary treatment for cervical cancer

    International Nuclear Information System (INIS)

    Hareyama, Masato; Oouchi, Atsushi; Shidou, Mitsuo

    1997-01-01

    From 1984 through 1993, 144 previous untreated patients with carcinoma of uterine cervix were treated with either low dose rate 137 Cs therapy (LDR) or high dose rate 60 Co therapy (HDR). The local failure rates for more than 2-years for the primary lesions were 11.8% (8 of 63 patients) for LDR and 18.0% (11 of 61 patients). Rectal complication rates were significantly lower for HDR versus LDR (14.3% VS. 32.8%. p<0.01). Also, bladder complication rates were significantly lower for HDR versus LDR (0% VS. 10.4%, p<0.005). Treatment results in term of local control were equivalent for HDR and LDR treatment. However, the incidence of complications was higher for the LDR group than for the HDR group. (author)

  17. The therapeutic alliance and therapist adherence as predictors of dropout from cognitive therapy for depression when combined with antidepressant medication.

    Science.gov (United States)

    Cooper, Andrew A; Strunk, Daniel R; Ryan, Elizabeth T; DeRubeis, Robert J; Hollon, Steven D; Gallop, Robert

    2016-03-01

    Previous psychotherapy research has examined the therapeutic alliance and therapist adherence as correlates or predictors of symptom change. While some initial evidence suggests the alliance is associated with risk of dropout in cognitive behavioral treatment for depression, evidence of such relations has been limited to date. We examined the relation of these psychotherapy process variables and dropout in the context of cognitive therapy for depression when provided in combination with pharmacotherapy. Patients were randomized to the CT plus pharmacotherapy condition of a clinical trial for chronic or recurrent depression. Consistent with the spirit of personalized medicine, patients were treated until they met remission and recovery criteria (or reached the maximum allowable time in the study). In a sample of 176 patients, we examined observer-rated alliance and therapist adherence in the first three CT sessions as potential predictors of treatment dropout. The therapeutic alliance and one facet of therapist adherence (i.e., Behavioral Methods/Homework) predicted reduced odds of dropout. Therapist use of Negotiating/Structuring predicted greater likelihood of dropout, but only when other variables were included in the model. Process ratings were not available for concurrent pharmacotherapy sessions. A minority of patients did not have session recordings available. Results are consistent with the possibility that the therapeutic alliance and therapists' focus on homework and behavioral methods promote treatment retention in combined treatment for depression. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Drop-out from a psychodynamic group psychotherapy outpatient unit.

    Science.gov (United States)

    Jensen, Hans Henrik; Mortensen, Erik Lykke; Lotz, Martin

    2014-11-01

    BACKGROUND. Drop-out from psychotherapy is common and represents a considerable problem in clinical practice and research. Aim. To explore pre-treatment predictors of early and late drop-out from psychodynamic group therapy in a public outpatient unit for non-psychotic disorders in Denmark. Methods. Naturalistic design including 329 patients, the majority with mood, neurotic and personality disorders referred to 39-session group therapy. Predictors were socio-demographic and clinical variables, self-reported symptoms (Symptom Check List-90-Revised) and personality style (Millon Clinical Multiaxial Inventory-II). Drop-out was classified into early and late premature termination excluding patients who dropped out for external reasons. Results. Drop-out comprised 20.6% (68 patients) of the sample. Logistic regression revealed social functioning, vocational training, alcohol problems and antisocial behavior to be related to drop-out. However, early drop-outs had prominent agoraphobic symptoms, lower interpersonal sensitivity and compulsive personality features, and late drop-outs cognitive and somatic anxiety symptoms and antisocial personality features. Clinical and psychological variables accounted for the major part of variance in predictions of drop-out, which ranged from 15.6% to 19.5% (Nagelkerke Pseudo R-Square). Conclusion. Social functioning was consistently associated with drop-out, but personality characteristics and anxiety symptoms differentiated between early and late drop-out. Failure to discriminate between stages of premature termination may explain some of the inconsistencies in the drop-out literature. Clinical implications. Before selection of patients to time-limited psychodynamic groups, self-reported symptoms should be thoroughly considered. Patients with agoraphobic symptoms should be offered alternative treatment. Awareness of and motivation to work with interpersonal issues may be essential for compliance with group therapy.

  19. Measurement of viscosity of slush at high shear rates

    OpenAIRE

    小林, 俊一; 川村, 公之; 津川, 圭一; 和泉, 薫; Kobayashi, Shun'ichi; Kawamura, Kimiyuki; Tugawa, Keiichi; Izumi, Kaoru

    1988-01-01

    Measurements of viscosity of slush were carried out using a method of flow along an inclined smooth surface in a 0℃cold room. The method was used to get the values of viscosity under high shear rates (25 and 75s^). From our experiments two important results were obtained: 1) the viscosity of slush decreases with increasing shear rates; 2) The fluid behavior is pseudoplastic that the values of non-Newtonian index of viscosity were less than unity.

  20. Radiobiological aspects of continuous low dose-rate irradiation and fractionated high dose-rate irradiation

    International Nuclear Information System (INIS)

    Turesson, I.

    1990-01-01

    The biological effects of continuous low dose-rate irradiation and fractionated high dose-rate irradiation in interstitial and intracavitary radiotherapy and total body irradiation are discussed in terms of dose-rate fractionation sensitivity for various tissues. A scaling between dose-rate and fraction size was established for acute and late normal-tissue effects which can serve as a guideline for local treatment in the range of dose rates between 0.02 and 0.005 Gy/min and fraction sizes between 8.5 and 2.5 Gy. This is valid provided cell-cycle progression and proliferation can be ignored. Assuming that the acute and late tissue responses are characterized by α/β values of about 10 and 3 Gy and a mono-exponential repair half-time of about 3 h, the same total doses given with either of the two methods are approximately equivalent. The equivalence for acute and late non-hemopoietic normal tissue damage is 0.02 Gy/min and 8.5 Gy per fraction; 0.01 Gy/min and 5.5 Gy per fraction; and 0.005 Gy/min and 2.5Gy per fraction. A very low dose rate, below 0.005 Gy/min, is thus necessary to simulate high dose-rate radiotherapy with fraction sizes of about 2Gy. The scaling factor is, however, dependent on the repair half-time of the tissue. A review of published data on dose-rate effects for normal tissue response showed a significantly stronger dose-rate dependence for late than for acute effects below 0.02 Gy/min. There was no significant difference in dose-rate dependence between various acute non-hemopoietic effects or between various late effects. The consistent dose-rate dependence, which justifies the use of a general scaling factor between fraction size and dose rate, contrasts with the wide range of values for repair half-time calculated for various normal-tissue effects. This indicates that the model currently used for repair kinetics is not satisfactory. There are also few experimental data in the clinical dose-rate range, below 0.02 Gy/min. It is therefore

  1. U.S. High School Graduation Rates: Patterns and Explanations

    OpenAIRE

    Richard J. Murnane

    2013-01-01

    I survey the evidence on patterns in U.S. high school graduation rates over the period 1970–2010 and report the results of new research conducted to fill in holes in the evidence. I begin by pointing out the strengths and limitations of existing data sources. I then describe six striking patterns in graduation rates. They include stagnation over the last three decades of the twentieth century, significant race-, income-, and gender-based gaps, and significant increases in graduation rates o...

  2. THE AMERICAN HIGH SCHOOL GRADUATION RATE: TRENDS AND LEVELS*

    Science.gov (United States)

    Heckman, James J.; LaFontaine, Paul A.

    2009-01-01

    This paper applies a unified methodology to multiple data sets to estimate both the levels and trends in U.S. high school graduation rates. We establish that (a) the true rate is substantially lower than widely used measures; (b) it peaked in the early 1970s; (c) majority/minority differentials are substantial and have not converged for 35 years; (d) lower post-1970 rates are not solely due to increasing immigrant and minority populations; (e) our findings explain part of the slowdown in college attendance and rising college wage premiums; and (f) widening graduation differentials by gender help explain increasing male-female college attendance gaps. PMID:20625528

  3. THE AMERICAN HIGH SCHOOL GRADUATION RATE: TRENDS AND LEVELS.

    Science.gov (United States)

    Heckman, James J; Lafontaine, Paul A

    2010-05-01

    This paper applies a unified methodology to multiple data sets to estimate both the levels and trends in U.S. high school graduation rates. We establish that (a) the true rate is substantially lower than widely used measures; (b) it peaked in the early 1970s; (c) majority/minority differentials are substantial and have not converged for 35 years; (d) lower post-1970 rates are not solely due to increasing immigrant and minority populations; (e) our findings explain part of the slowdown in college attendance and rising college wage premiums; and (f) widening graduation differentials by gender help explain increasing male-female college attendance gaps.

  4. A review of reaction rates in high temperature air

    Science.gov (United States)

    Park, Chul

    1989-01-01

    The existing experimental data on the rate coefficients for the chemical reactions in nonequilibrium high temperature air are reviewed and collated, and a selected set of such values is recommended for use in hypersonic flow calculations. For the reactions of neutral species, the recommended values are chosen from the experimental data that existed mostly prior to 1970, and are slightly different from those used previously. For the reactions involving ions, the recommended rate coefficients are newly chosen from the experimental data obtained more recently. The reacting environment is assumed to lack thermal equilibrium, and the rate coefficients are expressed as a function of the controlling temperature, incorporating the recent multitemperature reaction concept.

  5. High rate tests of the LHCb RICH Upgrade system

    CERN Multimedia

    Blago, Michele Piero

    2016-01-01

    One of the biggest challenges for the upgrade of the LHCb RICH detectors from 2020 is to readout the photon detectors at the full 40 MHz rate of the LHC proton-proton collisions. A test facility has been setup at CERN with the purpose to investigate the behaviour of the Multi Anode PMTs, which have been proposed for the upgrade, and their readout electronics at high trigger rates. The MaPMTs are illuminated with a monochromatic laser that can be triggered independently of the readout electronics. A first series of tests, including threshold scans, is performed at low trigger rates (20 kHz) for both the readout and the laser with the purpose to characterise the behaviour of the system under test. Then the trigger rate is increased in two separate steps. First the MaPMTs are exposed to high illumination by triggering the pulsed laser at a high (20 MHz) repetition rate while the DAQ is readout at the same low rate as before. In this way the performance of the MaPMTs and the attached electronics can be evaluated ...

  6. Semi-solid electrodes having high rate capability

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, Yet-Ming; Duduta, Mihai; Holman, Richard; Limthongkul, Pimpa; Tan, Taison

    2017-11-28

    Embodiments described herein relate generally to electrochemical cells having high rate capability, and more particularly to devices, systems and methods of producing high capacity and high rate capability batteries having relatively thick semi-solid electrodes. In some embodiments, an electrochemical cell includes an anode, a semi-solid cathode that includes a suspension of an active material and a conductive material in a liquid electrolyte, and an ion permeable membrane disposed between the anode and the cathode. The semi-solid cathode has a thickness in the range of about 250 .mu.m-2,500 .mu.m, and the electrochemical cell has an area specific capacity of at least 5 mAh/cm.sup.2 at a C-rate of C/2.

  7. Ultra-Low-Dropout Linear Regulator

    Science.gov (United States)

    Thornton, Trevor; Lepkowski, William; Wilk, Seth

    2011-01-01

    A radiation-tolerant, ultra-low-dropout linear regulator can operate between -150 and 150 C. Prototype components were demonstrated to be performing well after a total ionizing dose of 1 Mrad (Si). Unlike existing components, the linear regulator developed during this activity is unconditionally stable over all operating regimes without the need for an external compensation capacitor. The absence of an external capacitor reduces overall system mass/volume, increases reliability, and lowers cost. Linear regulators generate a precisely controlled voltage for electronic circuits regardless of fluctuations in the load current that the circuit draws from the regulator.

  8. The High Cost of Failing to Reform Public Education in Texas. School Choice Issues in the State

    Science.gov (United States)

    Gottlob, Brian J.

    2008-01-01

    Research has documented a crisis in Texas high school graduation rates. Only 67 percent of Texas students graduate from high school, and some large urban districts have graduation rates of 50 percent or lower. This study documents the public costs of high school dropouts in Texas and examines how school choice could provide large public benefits…

  9. Do lifestyle factors and general health predict dropout among recently qualified eldercare workers? A two-year follow-up study.

    Science.gov (United States)

    Giver, Hanne; Faber, Anne; Strøyer, Jesper; Hannerz, Harald; Albertsen, Karen

    2011-05-01

    The eldercare sector in Denmark as in many industrialised countries is characterised by difficulties in retaining labour. Research suggests a possible imbalance between lifestyle and health among eldercare trainees and the demanding work encountered as eldercare employees. The aim of the present study was to determine the predictive effect of lifestyle and self-rated health on dropout from the Danish eldercare sector two years after qualification. We included 4,526 female eldercare trainees in the analyses of lifestyle parameters and 5,023 in the analyses of self-rated health. The participants in this prospective study were recruited from 27 of the 28 Danish colleges for eldercare. We linked survey data with national register data to obtain information about labour market attachment two years after qualification. The results of the present study showed that the poorer self-rated health, the higher the risk for dropout from the labour market (p lifestyle. We found that overweight/obesity (p = 0.0021 and p = 0.0012) as well as smoking (p = 0.0017) decreased the risk of dropout from eldercare into education. We found no support for increased likelihood of dropout among physically inactive. The results of the present study show that a poorer self-rated health is a predictor for dropout, not only from the eldercare two years after qualification, but from the labour market as a whole. However, the results were less consistent regarding the predictive effect of a detrimental lifestyle on dropout.

  10. Barriers for Nonparticipation and Dropout of Women in Cardiac Rehabilitation Programs: A Systematic Review.

    Science.gov (United States)

    Resurrección, Davinia M; Motrico, Emma; Rigabert, Alina; Rubio-Valera, Maria; Conejo-Cerón, Sonia; Pastor, Luis; Moreno-Peral, Patricia

    2017-08-01

    Cardiovascular disease (CVD) is a major health problem worldwide. Cardiac rehabilitation (CR) programs are effective in reducing mortality and improving the quality of life of patients with CVD. Women are under-represented in CR and have a higher dropout rate than men. We aimed to systematically review the literature on barriers perceived by women with CVD affecting their nonparticipation in and/or dropping out from CR programs. Systematic review was done using MEDLINE, Embase, Scopus, Open Grey, and Cochrane Database from inception to September 2016. Search terms included (1) heart disease and other cardiac conditions, (2) CR and secondary prevention, and (3) nonparticipation in and/or dropout. Databases were searched following the "participants, interventions, comparisons, outcomes, and study design" method. A total of 24 studies (17 descriptive, 6 qualitative, and 1 randomized controlled trial) reporting several barriers were grouped into five broad categories: intrapersonal barriers (self-reported health, health beliefs, lack of time, motivation, and religious reasons); interpersonal barriers (lack of family/social support and work conflicts); logistical barriers (transport, distance, and availability of personal/community resources); CR program barriers (services offered, group format, exercise component, and CR sessions); and health system barriers (lack of referral, cost, negative experiences with the health system, and language). We found differences between the barriers related to nonparticipation in and dropout from CR programs. Women reported multilevel barriers for nonparticipation in and dropout from CR programs. Future clinical guidelines should evaluate and eliminate these barriers to improve adherence to CR programs in women. In addition, understanding the barriers for nonparticipation and dropout may be beneficial for future intervention trials.

  11. Characteristics of Early Community College Dropouts. CCRC Analytics

    Science.gov (United States)

    Crosta, Peter M.

    2013-01-01

    For colleges to develop effective dropout prevention strategies, it is necessary to have a clear picture of who these early dropouts are. This report identifies distinguishing characteristics of this group by analyzing six years of transcript data on 14,429 first-time college students who in 2005 and 2006 enrolled at one of five community colleges…

  12. Dropout from exercise programs for seniors: A prospective cohort study

    NARCIS (Netherlands)

    Stiggelbout, M.; Hopman-Rock, M.; Tak, E.; Lechner, L.; Mechelen, W. van

    2005-01-01

    This study examines dropout incidence, moment of dropout, and switching behavior in organized exercise programs for seniors in the Netherlands, as determined in a prospective cohort study (with baseline measurements at the start of the exercise program and follow-up after 6 months; N = 1,725,

  13. Socioeconomic differences in school dropout among young adults

    DEFF Research Database (Denmark)

    Winding, Trine Nøhr; Andersen, Johan Hviid

    2015-01-01

    Background School dropout in adolescence is an important social determinant of health inequality in a lifetime perspective. It is commonly accepted that parental background factors are associated with later dropout, but to what extent social relations mediate this association is not yet fully...

  14. Dropout and completion in higher education in Europe: main report

    NARCIS (Netherlands)

    Vossensteyn, Johan J.; Kottmann, Andrea; Jongbloed, Benjamin W.A.; Kaiser, Franciscus; Cremonini, Leon; Stensaker, Bjorn; Hovdhaugen, Elisabeth; Wollscheid, Sabine

    2015-01-01

    Improving completion and reducing dropout in higher education are key concerns for higher education in Europe. This study on dropout and completion in higher education in Europe demonstrates that national governments and higher education institutions use three different study success objectives:

  15. Psychological Treatment as Part of Dropout Prevention: An Israeli Program

    Science.gov (United States)

    Schwartz, Hava; Hain, Rebecca

    2014-01-01

    This article reports on the integration of psychotherapy in a comprehensive dropout prevention program developed at the Dean of Students' office of Ben-Gurion University of the Negev in Israel. The program's psychologists conducted psychotherapy with a subset of dropout prevention program participants who had reacted with emotional turmoil to the…

  16. Electron Dropout Echoes Induced by Interplanetary Shock: A Statistical Study

    Science.gov (United States)

    Liu, Z.; Zong, Q.; Hao, Y.; Zhou, X.; Ma, X.; Liu, Y.

    2017-12-01

    "Electron dropout echo" as indicated by repeated moderate dropout and recovery signatures of the flux of energetic electron in the out radiation belt region has been investigated systematically. The electron dropout and its echoes are usually found for higher energy (> 300 keV) channels fluxes, whereas the flux enhancements are obvious for lower energy electrons simultaneously after the interplanetary shock arrives at the Earth's geosynchronous orbit. 104 dropout echo events have been found from 215 interplanetary shock events from 1998 to 2007 based on LANL satellite data. In analogy to substorm injections, these 104 events could be naturally divided into two categories: dispersionless (49 events) or dispersive (55 events) according to the energy dispersion of the initial dropout. It is found that locations of dispersionless events are distributed mainly in the duskside magnetosphere. Further, the obtained locations derived from dispersive events with the time-of-flight technique of the initial dropout regions are mainly located at the duskside as well. Statistical studies have shown that the effect of shock normal, interplanetary magnetic field Bz and solar wind dynamic pressure may be insignificant to these electron dropout events. We suggest that the electric field impulse induced by the IP shock produces a more pronounced inward migration of electrons at the dusk side, resulting in the observed dusk-side moderate dropout of electron flux and its consequent echoes.

  17. Diplomas Count 2013: Second Chances--Turning Dropouts into Graduates

    Science.gov (United States)

    Education Week, 2013

    2013-01-01

    The 2013 edition of "Diplomas Count," entitled "Second Chances: Turning Dropouts into Graduates," examines dropout recovery and innovative strategies for returning to the educational fold the 1 million students who leave school without a diploma each year. "Education Week's" journalists investigate interventions that…

  18. School Dropout Indicators, Trends, and Interventions for School Counselors

    Science.gov (United States)

    Dockery, Donna J.

    2012-01-01

    School counselors are expected to develop programs that promote academic success for all students, including those at risk for dropping out of school. Knowledge of key indicators of potential dropouts and current trends in dropout prevention research may assist school counselors in better understanding this complex issue. Implementing recommended…

  19. ACRES At-Risk Task Force: Dropout Survey.

    Science.gov (United States)

    Bull, Kay S.; And Others

    This paper describes a study by the American Council on Rural Special Education (ACRES) to determine its membership's opinions on priorities and expertise regarding the dropout problem. ACRES members, primarily rural special-education teachers, parents, and collateral service workers, were surveyed about the dropout problem and what research they…

  20. High-rate performance of muon drift tube detectors

    International Nuclear Information System (INIS)

    Schwegler, Philipp

    2014-01-01

    The Large Hadron Collider (LHC) at the European Centre for Particle Physics, CERN, collides protons with an unprecedentedly high centre-of-mass energy and luminosity. The collision products are recorded and analysed by four big experiments, one of which is the ATLAS detector. In parallel with the first LHC run from 2009 to 2012, which culminated in the discovery of the last missing particle of the Standard Model of particle physics, the Higgs boson, planning of upgrades of the LHC for higher instantaneous luminosities (HL-LHC) is already progressing. The high instantaneous luminosity of the LHC puts high demands on the detectors with respect to radiation hardness and rate capability which are further increased with the luminosity upgrade. In this thesis, the limitations of the Muon Drift Tube (MDT) chambers of the ATLAS Muon Spectrometer at the high background counting rates at the LHC and performance of new small diameter muon drift tube (sMDT) detectors at the even higher background rates at HL-LHC are studied. The resolution and efficiency of sMDT chambers at high γ-ray and proton irradiation rates well beyond the ones expected at HL-LHC have been measured and the irradiation effects understood using detailed simulations. The sMDT chambers offer an about an order of magnitude better rate capability and are an ideal replacement for the MDT chambers because of compatibility of services and read-out. The limitations of the sMDT chambers are now in the read-out electronics, taken from the MDT chambers, to which improvements for even higher rate capability are proposed.

  1. High Strain Rate Tensile Testing of Silver Nanowires: Rate-Dependent Brittle-to-Ductile Transition.

    Science.gov (United States)

    Ramachandramoorthy, Rajaprakash; Gao, Wei; Bernal, Rodrigo; Espinosa, Horacio

    2016-01-13

    The characterization of nanomaterials under high strain rates is critical to understand their suitability for dynamic applications such as nanoresonators and nanoswitches. It is also of great theoretical importance to explore nanomechanics with dynamic and rate effects. Here, we report in situ scanning electron microscope (SEM) tensile testing of bicrystalline silver nanowires at strain rates up to 2/s, which is 2 orders of magnitude higher than previously reported in the literature. The experiments are enabled by a microelectromechanical system (MEMS) with fast response time. It was identified that the nanowire plastic deformation has a small activation volume (ductile failure mode transition was observed at a threshold strain rate of 0.2/s. Transmission electron microscopy (TEM) revealed that along the nanowire, dislocation density and spatial distribution of plastic regions increase with increasing strain rate. Furthermore, molecular dynamic (MD) simulations show that deformation mechanisms such as grain boundary migration and dislocation interactions are responsible for such ductility. Finally, the MD and experimental results were interpreted using dislocation nucleation theory. The predicted yield stress values are in agreement with the experimental results for strain rates above 0.2/s when ductility is pronounced. At low strain rates, random imperfections on the nanowire surface trigger localized plasticity, leading to a brittle-like failure.

  2. Couple Therapy with Veterans: Early Improvements and Predictors of Early Dropout.

    Science.gov (United States)

    Fischer, Melanie S; Bhatia, Vickie; Baddeley, Jenna L; Al-Jabari, Rawya; Libet, Julian

    2017-07-28

    Family services within Veterans Affairs Medical Centers fulfill an important role in addressing relationship distress among Veterans, which is highly prevalent and comorbid with psychopathology. However, even for evidence-based couple therapies, effectiveness is weaker compared to controlled studies, maybe because many Veteran couples drop out early and do not reach the "active" treatment stage after the 3-4 session assessment. In order to improve outcomes, it is critical to identify couples at high risk for early dropout, and understand whether couples may benefit from the assessment as an intervention. The current study examined (a) demographics, treatment delivery mode, relationship satisfaction, and psychological symptoms as predictors of dropout during and immediately following the assessment phase, and (b) changes in relationship satisfaction during assessment. 174 couples completed questionnaires during routine intake procedures. The main analyses focused on 140 male Veterans and their female civilian partners; 36.43% dropped out during the assessment phase and 24.74% of the remaining couples immediately following the first treatment session. More severe depressive symptoms in non-Veteran partners were associated with dropout during assessment. Relationship satisfaction improved significantly during the assessment phase for couples who did not drop out, with larger gains for non-Veteran partners. No demographics or treatment delivery mode were associated with dropout. Although more research is needed on engaging couples at risk for early dropout and maximizing early benefits, the findings suggest that clinicians should attend to the civilian partner's and Veteran's depressive symptoms at intake and consider the assessment part of active treatment. © 2017 Family Process Institute.

  3. High data rate coding for the space station telemetry links.

    Science.gov (United States)

    Lumb, D. R.; Viterbi, A. J.

    1971-01-01

    Coding systems for high data rates were examined from the standpoint of potential application in space-station telemetry links. Approaches considered included convolutional codes with sequential, Viterbi, and cascaded-Viterbi decoding. It was concluded that a high-speed (40 Mbps) sequential decoding system best satisfies the requirements for the assumed growth potential and specified constraints. Trade-off studies leading to this conclusion are viewed, and some sequential (Fano) algorithm improvements are discussed, together with real-time simulation results.

  4. Predicting High Frequency Exchange Rates using Machine Learning

    OpenAIRE

    Palikuca, Aleksandar; Seidl,, Timo

    2016-01-01

    This thesis applies a committee of Artificial Neural Networks and Support Vector Machines on high-dimensional, high-frequency EUR/USD exchange rate data in an effort to predict directional market movements on up to a 60 second prediction horizon. The study shows that combining multiple classifiers into a committee produces improved precision relative to the best individual committee members and outperforms previously reported results. A trading simulation implementing the committee classifier...

  5. Decay rate of the false vacuum at high tempratures

    International Nuclear Information System (INIS)

    Eboli, O.J.P.; Marques, G.C.

    1984-01-01

    Within the semiclassical approach, the high temperaure behaviour of the decay rate of the metastable vacuum in Field Theory is investigated. It is shown that, contrarily to what has been proposed in the literature, the pre-exponential factor exhibits a nontrivial dependence on the temperature. Furthermore, this dependence is such that at very high temperatures it is as important as the exponential factor and consequently it spoils many conclusions drawn up to now on Cosmological Phase Transitions. (Author) [pt

  6. Parenting practices and school dropout: a longitudinal study.

    Science.gov (United States)

    Blondal, Kristjana S; Adalbjarnardottir, Sigrun

    2009-01-01

    Adolescents' perceptions of parenting style and parental involvement in their education were examined longitudinally and related to school dropout among Icelandic youth (N = 427). Results indicated that adolescents who, at age 14, characterized their parents as authoritative (showing acceptance and supervision) were more likely to have completed upper secondary school by age 22 than adolescents from non-authoritative families, controlling for adolescents' gender, socioeconomic status (SES), temperament, and parental involvement. Parenting style seems to more strongly predict school dropout than parental involvement. Further, parenting style may moderate the relationship between parental involvement and dropout, but not in all groups; only in authoritative families does parental involvement decrease the likelihood of school dropout. Furthermore, even after controlling for previous academic achievement, adolescents from authoritative families were less likely to drop out than adolescents from authoritarian and neglectful families. These findings emphasize the importance of encouraging quality parent-child relationships in order to reduce the likelihood of school dropout.

  7. Electrophoretic Deposition of Gallium with High Deposition Rate

    Directory of Open Access Journals (Sweden)

    Hanfei Zhang

    2014-12-01

    Full Text Available In this work, electrophoretic deposition (EPD is reported to form gallium thin film with high deposition rate and low cost while avoiding the highly toxic chemicals typically used in electroplating. A maximum deposition rate of ~0.6 μm/min, almost one order of magnitude higher than the typical value reported for electroplating, is obtained when employing a set of proper deposition parameters. The thickness of the film is shown to increase with deposition time when sequential deposition is employed. The concentration of Mg(NO32, the charging salt, is also found to be a critical factor to control the deposition rate. Various gallium micropatterns are obtained by masking the substrate during the process, demonstrating process compatibility with microfabrication. The reported novel approach can potentially be employed in a broad range of applications with Ga as a raw material, including microelectronics, photovoltaic cells, and flexible liquid metal microelectrodes.

  8. READOUT ELECTRONICS FOR A HIGH-RATE CSC DETECTOR

    International Nuclear Information System (INIS)

    OCONNOR, P.; GRATCHEV, V.; KANDASAMY, A.; POLYCHRONAKOS, V.; TCHERNIATINE, V.; PARSONS, J.; SIPPACH, W.

    1999-01-01

    A readout system for a high-rate muon Cathode Strip Chamber (CSC) is described. The system, planned for use in the forward region of the ATLAS muon spectrometer, uses two custom CMOS integrated circuits to achieve good position resolution at a flux of up to 2,500 tracks/cm 2 /s

  9. Digital approach to high rate gamma-ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Korolczuk, Stefan; Mianowski, Slawomir; Rzadkiewicz, Jacek; Sibczynski, Pawel; Swiderski, Lukasz; Szewinski, Jaroslaw; Zychor, Izabella [Narodowe Centrum Badan Jadrowych (NCBJ), 05-400 Otwock, (Poland)

    2015-07-01

    Basic concepts and preliminary results of creating high rate digital spectrometry system using efficient ADCs and latest FPGA are presented as well as a comparison with commercially available devices. The possibility to use such systems, coupled to scintillators, in plasma experiments is discussed. (authors)

  10. High rate of teenage pregnancy and sexually transmitted infections ...

    African Journals Online (AJOL)

    There is increased in teenage pregnancy despite the presence of dual protection practice and health care awareness programmes related to health and sexuality education in South Africa. The present study explores the underlying causes of high teenage pregnancy and sexually transmitted diseases rates, including HIV ...

  11. Twinning in copper deformed at high strain rates

    Indian Academy of Sciences (India)

    Abstract. Copper samples having varying microstructures were deformed at high strain rates using a split-. Hopkinson pressure bar. Transmission electron microscopy results show deformation twins present in samples that were both annealed and strained, whereas samples that were annealed and left unstrained, as well ...

  12. High Frame Rate Synthetic Aperture 3D Vector Flow Imaging

    DEFF Research Database (Denmark)

    Villagómez Hoyos, Carlos Armando; Holbek, Simon; Stuart, Matthias Bo

    2016-01-01

    , current volumetric ultrasonic flow methods are limited to one velocity component or restricted to a reduced field of view (FOV), e.g. fixed imaging planes, in exchange for higher temporal resolutions. To solve these problems, a previously proposed accurate 2-D high frame rate vector flow imaging (VFI...

  13. Sphaleron rate at high temperature in 1+1 dimensions

    International Nuclear Information System (INIS)

    Smit, Jan; Tang, W.H.

    1999-01-01

    We resolve the controversy in the high temperature behavior of the sphaleron rate in the abelian Higgs model in 1+1 dimensions. The T 2 behavior at intermediate lattice spacings is found to change into T ((2)/(3)) behavior in the continuum limit. The results are supported by analytic arguments that the classical approximation is good for this model

  14. Identification of Liver Transplant Candidates with Hepatocellular Carcinoma and Very Low Dropout Risk: Implications for the Current Organ Allocation Policy

    Science.gov (United States)

    Mehta, Neil; Dodge, Jennifer L.; Goel, Aparna; Roberts, John P.; Hirose, Ryutaro; Yao, Francis Y.

    2013-01-01

    It has been shown that patients with hepatocellular carcinoma (HCC) meeting UNOS T2 (Milan) criteria are advantaged compared to patients without HCC under the current organ allocation system for liver transplant (LT). We hypothesize that within T2 HCC, there is a subgroup with a low risk of waitlist dropout, and should not receive the same listing priority. This study evaluated 398 consecutive patients with T2 HCC listed for LT with MELD exception from 2005 to 2010 at our center. Competing risk (CR) regression was used to determine predictors of dropout. Probabilities of dropout due to tumor progression or death without LT by CR analysis were 9.4% at 6 months and 19.6% at 12 months. The median time from listing to LT was 8.8 months, and from listing to dropout or death without LT was 7.2 months. Significant predictors of dropout or death without LT by multivariate CR regression included 1 tumor 3–5 cm (vs. ≤3 cm), 2 or 3 tumors, lack of a complete response to first loco-regional therapy (LRT), and high alpha-fetoprotein (AFP) after the first LRT. A subgroup (19.9%) meeting the following criteria: 1 tumor 2 to 3 cm, complete response after first LRT, and AFP ≤20 ng/mL after first LRT, had 1- and 2-year probabilities of dropout of 1.3% and 1.6%, respectively, compared to 21.6% and 26.5% for all other patients (p=0.004). In conclusion, a combination of tumor characteristics and complete response to the first LRT define a subgroup of patients with a very low risk of waitlist dropout who does not require the same listing priority. Our results may have important implications for the organ allocation policy for HCC. PMID:24285611

  15. High production rate of IBAD-MgO buffered substrate

    Energy Technology Data Exchange (ETDEWEB)

    Yoshizumi, M., E-mail: myoshizumi@istec.or.j [Superconductivity Research Laboratory, ISTEC, Shinonome 1-10-13, Koto-ku, Tokyo 135-0062 (Japan); Miyata, S.; Ibi, A.; Fukushima, H.; Yamada, Y.; Izumi, T.; Shiohara, Y. [Superconductivity Research Laboratory, ISTEC, Shinonome 1-10-13, Koto-ku, Tokyo 135-0062 (Japan)

    2009-10-15

    The conventional IBAD (Ion Beam Assisted Deposition) process using fluorite materials yields low production rates, resulting in high production cost, which reduces the motivation for practical application in spite of its high quality. The IBAD process using rock salt materials, e.g. MgO, is well known as a strong candidate of practical application due to its potential of high production rate and high in-plane grain alignment. In this work, the IBAD-MgO process was investigated for a newly developed architecture of PLD (Pulsed Laser Deposition)-CeO{sub 2}/sputter-LMO (LaMnO{sub 3})/IBAD-MgO/sputter-GZO (Gd{sub 2}Zr{sub 2}O{sub 7})/Hastelloy{sup TM} to make long buffered metal tapes with high properties and a high production rate. The 50 m-long IBAD-MgO substrates with about 4 deg. of DELTAphiCeO{sub 2} in an XRD phi scan could be fabricated repeatedly. A GdBCO (GdBa{sub 2}Cu{sub 3}O{sub x}) layer deposited on the buffered substrate showed the minimum I{sub c} value of 325 A/cm-w in a 41 m-long tape. Almost of the tape showed 500-600 A/cm-w of I{sub c} value. The deposition time for the IBAD-MgO layer was 60 s which was about 2 orders of magnitude shorter than the conventional IBAD process. The production rate of 24 m/h was realized at the IBAD-MgO process to fabricate the GdBCO coated conductor with high J{sub c} and I{sub c} properties.

  16. Student Dropout at the Hellenic Open University: Evaluation of the Graduate Program, "Studies in Education"

    Directory of Open Access Journals (Sweden)

    Dimitris Vergidis

    2002-10-01

    Full Text Available This study traces the root causes of dropout rates in one post-graduate course “Studies in Education,” offered by the Hellenic Open University (HOU. From our research findings, it was found that the main cause of dropping out stem from a combination of adult learners’ obligations, specifically balancing their academic workload with their employment commitments and family obligations (mainly for female students. The second reason for dropout rates among adult distance education learners include students’ miscalculation of the available time for studying and their underestimation of the extra effort required for effective learning. These reasons can be compared to the educational material, which, in general, was not considered overly difficult and did not appear to compel students to abandon their studies.

  17. Physical nature of strain rate sensitivity of metals and alloys at high strain rates

    Science.gov (United States)

    Borodin, E. N.; Gruzdkov, A. A.; Mayer, A. E.; Selyutina, N. S.

    2018-04-01

    The role of instabilities of plastic flow at plastic deformation of various materials is one of the important cross-disciplinary problems which is equally important in physics, mechanics and material science. The strain rate sensitivities under slow and high strain rate conditions of loading have different physical nature. In the case of low strain rate, the sensitivity arising from the inertness of the defect structures evolution can be expressed by a single parameter characterizing the plasticity mechanism. In our approach, this is the value of the characteristic relaxation time. In the dynamic case, there are additional effects of “high-speed sensitivity” associated with the micro-localization of the plastic flow near the stress concentrators. In the frames of mechanical description, this requires to introduce additional strain rate sensitivity parameters, which is realized in numerous modifications of Johnson–Cook and Zerilli–Armstrong models. The consideration of both these factors is fundamental for an adequate description of the problems of dynamic deformation of highly inhomogeneous metallic materials such as steels and alloys. The measurement of the dispersion of particle velocities on the free surface of a shock-loaded material can be regarded as an experimental expression of the effect of micro-localization. This is also confirmed by our results of numerical simulation of the propagation of shock waves in a two-dimensional formulation and analytical estimations.

  18. Radiation shielding and dose rate distribution for the building of the high dose rate accelerator

    International Nuclear Information System (INIS)

    Matsuda, Koji; Takagaki, Torao; Nakase, Yoshiaki; Nakai, Yohta.

    1984-03-01

    A high dose rate electron accelerator was established at Osaka Laboratory for Radiation Chemistry, Takasaki Establishment, JAERI in the fiscal year of 1975. This report shows the fundamental concept for the radiation shielding of the accelerator building and the results of their calculations which were evaluated through the model experiments. After the construction of the building, the leak radiation was measured in order to evaluate the calculating method of radiation shielding. Dose rate distribution of X-rays was also measured in the whole area of the irradiation room as a data base. (author)

  19. High strain-rate soft material characterization via inertial cavitation

    Science.gov (United States)

    Estrada, Jonathan B.; Barajas, Carlos; Henann, David L.; Johnsen, Eric; Franck, Christian

    2018-03-01

    Mechanical characterization of soft materials at high strain-rates is challenging due to their high compliance, slow wave speeds, and non-linear viscoelasticity. Yet, knowledge of their material behavior is paramount across a spectrum of biological and engineering applications from minimizing tissue damage in ultrasound and laser surgeries to diagnosing and mitigating impact injuries. To address this significant experimental hurdle and the need to accurately measure the viscoelastic properties of soft materials at high strain-rates (103-108 s-1), we present a minimally invasive, local 3D microrheology technique based on inertial microcavitation. By combining high-speed time-lapse imaging with an appropriate theoretical cavitation framework, we demonstrate that this technique has the capability to accurately determine the general viscoelastic material properties of soft matter as compliant as a few kilopascals. Similar to commercial characterization algorithms, we provide the user with significant flexibility in evaluating several constitutive laws to determine the most appropriate physical model for the material under investigation. Given its straightforward implementation into most current microscopy setups, we anticipate that this technique can be easily adopted by anyone interested in characterizing soft material properties at high loading rates including hydrogels, tissues and various polymeric specimens.

  20. Miniaturized Stretchable and High-Rate Linear Supercapacitors

    Science.gov (United States)

    Zhu, Wenjun; Zhang, Yang; Zhou, Xiaoshuang; Xu, Jiang; Liu, Zunfeng; Yuan, Ningyi; Ding, Jianning

    2017-07-01

    Linear stretchable supercapacitors have attracted much attention because they are well suited to applications in the rapidly expanding field of wearable electronics. However, poor conductivity of the electrode material, which limits the transfer of electrons in the axial direction of the linear supercapacitors, leads to a serious loss of capacity at high rates. To solve this problem, we use gold nanoparticles to decorate aligned multiwall carbon nanotube to fabricate stretchable linear electrodes. Furthermore, we have developed fine stretchable linear supercapacitors, which exhibited an extremely high elasticity up to 400% strain with a high capacitance of about 8.7 F g-1 at the discharge current of 1 A g-1.

  1. Study the Precipitation of Radiation Belt Electrons during the Rapid Dropout Events

    Science.gov (United States)

    Tu, W.; Cunningham, G.; Li, X.; Chen, Y.

    2015-12-01

    During the main phase of storms, the relativistic electron flux in the radiation belt can drop by orders of magnitude on timescales of a few hours. Where do the electrons go? This is one of the most important outstanding questions in radiation belt studies. Radiation belt electrons can be lost either by transport across the magnetopause into interplanetary space or by precipitation into the atmosphere. In this work we first conduct a survey of the MeV electron dropouts using the Van Allen Probes data in conjunction with the low-altitude measurements of precipitating electrons by 6 NOAA/POES satellites. The dropout events are categorized into three types: precipitation-loss dominant, outward radial diffusion dominant, or with contributions from both mechanisms. The survey results suggest the relative importance of precipitation and outward radial diffusion to the fast dropouts of radiation belt electrons, and their extent in L-shell and electron energy. Then, for specific events identified as dominated by precipitation loss, we use the Drift-Diffusion model, which includes the effects of azimuthal drift and pitch angle diffusion, to simulate both the electron dropout observed by Van Allen Probes and the distributions of drift-loss-cone electrons observed by multiple low-earth-orbit satellites (6 POES and the Colorado Student Space Weather Experiment). The model quantifies the electron precipitation loss and pitch angle diffusion coefficient, Dxx, with high temporal and spatial resolution. Finally, by comparing the Dxx derived from the model with those estimated from the quasi-linear theory using wave data from Van Allen Probes and other event-specific wave models, we are able to test the validity of quasi-linear theory and seek direct evidence of the wave-particle interactions during the dropouts.

  2. HIGH-RATE ANAEROBIC TREATMENT OF ALCOHOLIC WASTEWATERS

    Directory of Open Access Journals (Sweden)

    Florencio L.

    1997-01-01

    Full Text Available Modern high-rate anaerobic wastewater treatment processes are rapidly becoming popular for industrial wastewater treatment. However, until recently stable process conditions could not be guaranteed for alcoholic wastewaters containing higher concentrations of methanol. Although methanol can be directly converted into methane by methanogens, under specific conditions it can also be converted into acetate and butyrate by acetogens. The accumulation of volatile fatty acids can lead to reactor instability in a weakly buffered reactor. Since this process was insufficiently understood, the application of high-rate anaerobic reactors was highly questionable. This research investigated the environmental factors that are of importance in the predominance of methylotrophic methanogens over acetogens in a natural mixed culture during anaerobic wastewater treatment in upflow anaerobic sludge bed reactors. Technological and microbiological aspects were investigated. Additionally, the route by which methanol is converted into methane is also presented

  3. Spallation model for the high strain rates range

    Science.gov (United States)

    Dekel, E.; Eliezer, S.; Henis, Z.; Moshe, E.; Ludmirsky, A.; Goldberg, I. B.

    1998-11-01

    Measurements of the dynamic spall strength in aluminum and copper shocked by a high power laser to pressures of hundreds of kbars show a rapid increase in the spall strength with the strain rate at values of about 107 s-1. We suggest that this behavior is a result of a change in the spall mechanism. At low strain rates the spall is caused by the motion and coalescence of material's initial flaws. At high strain rates there is not enough time for the flaws to move and the spall is produced by the formation and coalescence of additional cavities where the interatomic forces become dominant. Material under tensile stress is in a metastable condition and cavities of a critical radius are formed in it due to thermal fluctuations. These cavities grow due to the tension. The total volume of the voids grow until the material disintegrates at the spall plane. Simplified calculations based on this model, describing the metal as a viscous liquid, give results in fairly good agreement with the experimental data and predict the increase in spall strength at high strain rates.

  4. Highly variable rates of genome rearrangements between hemiascomycetous yeast lineages.

    Directory of Open Access Journals (Sweden)

    2006-03-01

    Full Text Available Hemiascomycete yeasts cover an evolutionary span comparable to that of the entire phylum of chordates. Since this group currently contains the largest number of complete genome sequences it presents unique opportunities to understand the evolution of genome organization in eukaryotes. We inferred rates of genome instability on all branches of a phylogenetic tree for 11 species and calculated species-specific rates of genome rearrangements. We characterized all inversion events that occurred within synteny blocks between six representatives of the different lineages. We show that the rates of macro- and microrearrangements of gene order are correlated within individual lineages but are highly variable across different lineages. The most unstable genomes correspond to the pathogenic yeasts Candida albicans and Candida glabrata. Chromosomal maps have been intensively shuffled by numerous interchromosomal rearrangements, even between species that have retained a very high physical fraction of their genomes within small synteny blocks. Despite this intensive reshuffling of gene positions, essential genes, which cluster in low recombination regions in the genome of Saccharomyces cerevisiae, tend to remain syntenic during evolution. This work reveals that the high plasticity of eukaryotic genomes results from rearrangement rates that vary between lineages but also at different evolutionary times of a given lineage.

  5. Precise muon drift tube detectors for high background rate conditions

    Energy Technology Data Exchange (ETDEWEB)

    Engl, Albert

    2011-08-04

    The muon spectrometer of the ATLAS-experiment at the Large Hadron Collider consists of drift tube chambers, which provide the precise measurement of trajectories of traversing muons. In order to determine the momentum of the muons with high precision, the measurement of the position of the muon in a single tube has to be more accurate than {sigma}{<=}100 {mu}m. The large cross section of proton-proton-collisions and the high luminosity of the accelerator cause relevant background of neutrons and {gamma}s in the muon spectrometer. During the next decade a luminosity upgrade to 5.10{sup 34} cm{sup -2}s{sup -1} is planned, which will increase the background counting rates considerably. In this context this work deals with the further development of the existing drift chamber technology to provide the required accuracy of the position measurement under high background conditions. Two approaches of improving the drift tube chambers are described: - In regions of moderate background rates a faster and more linear drift gas can provide precise position measurement without changing the existing hardware. - At very high background rates drift tube chambers consisting of tubes with a diameter of 15 mm are a valuable candidate to substitute the CSC muon chambers. The single tube resolution of the gas mixture Ar:CO{sub 2}:N{sub 2} in the ratio of 96:3:1 Vol %, which is more linear and faster as the currently used drift gas Ar:CO{sub 2} in the ratio of 97:3 Vol %, was determined at the Cosmic Ray Measurement Facility at Garching and at high {gamma}-background counting rates at the Gamma Irradiation Facility at CERN. The alternative gas mixture shows similar resolution without background. At high background counting rates it shows better resolution as the standard gas. To analyse the data the various parts of the setup have to be aligned precisely to each other. The change to an alternative gas mixture allows the use of the existing hardware. The second approach are drift tubes

  6. Iodine laser of high efficiency and fast repetition rate

    Energy Technology Data Exchange (ETDEWEB)

    Hohla, K; Witte, K J

    1976-07-01

    The scaling laws of an iodine laser of high efficiency and fast repetition rate are reported. The laser is pumped with a new kind of low pressure Hg-UV-lamps which convert 32% of the electrical input in UV-light in the absorption band of the iodine laser and which can be fired up to 100 Hz. Details of a 10 kJ/1 nsec system as dimensions, energy density, repetition rate, flow velocity, gas composition and gas pressure and the overall efficiency are given which is expected to be about 2%.

  7. Study of magnetorheological fluids at high shear rates

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiaojie; Gordaninejad, Faramarz [University of Nevada, Department of Mechanical Engineering, Reno, NV (United States)

    2006-08-15

    The tunable rheological properties of magnetorheological (MR) materials at high shear rates are studied using a piston-driven flow-mode-type rheometer. The proposed method provides measurement of the apparent viscosity and yield stress of MR fluids for a shear rate range of 50 to 40,000 s{sup -1}. The rheological properties of a commercial MR fluid, as well as a newly developed MR polymeric gel, and a ferrofluid-based MR fluid are investigated. The results for apparent viscosity and dynamic and static shear stresses under different applied magnetic fields are reported. (orig.)

  8. Study of the Factors Responsible for the Dropouts from the BSc Programme of Indira Gandhi National Open University

    Directory of Open Access Journals (Sweden)

    Bharat Inder Fozdar

    2006-12-01

    Full Text Available This paper presents a report on students who decided to drop out of the BSc programme offered by Indira Gandhi National Open University (IGNOU. This study was designed to determine the reasons leading to students’ decisions to withdraw from the programme. Identified in this study are nine major reasons for dropouts. Results of this study lead to several suggestions for improving current instructional and delivery strategies of IGNOU’s BSc Programme. Following such suggestions could help to reduce students’ dropout rate for this particular programme through implementation of timely interventions at different critical stages of their learning journey.

  9. Palaeohistological Evidence for Ancestral High Metabolic Rate in Archosaurs.

    Science.gov (United States)

    Legendre, Lucas J; Guénard, Guillaume; Botha-Brink, Jennifer; Cubo, Jorge

    2016-11-01

    Metabolic heat production in archosaurs has played an important role in their evolutionary radiation during the Mesozoic, and their ancestral metabolic condition has long been a matter of debate in systematics and palaeontology. The study of fossil bone histology provides crucial information on bone growth rate, which has been used to indirectly investigate the evolution of thermometabolism in archosaurs. However, no quantitative estimation of metabolic rate has ever been performed on fossils using bone histological features. Moreover, to date, no inference model has included phylogenetic information in the form of predictive variables. Here we performed statistical predictive modeling using the new method of phylogenetic eigenvector maps on a set of bone histological features for a sample of extant and extinct vertebrates, to estimate metabolic rates of fossil archosauromorphs. This modeling procedure serves as a case study for eigenvector-based predictive modeling in a phylogenetic context, as well as an investigation of the poorly known evolutionary patterns of metabolic rate in archosaurs. Our results show that Mesozoic theropod dinosaurs exhibit metabolic rates very close to those found in modern birds, that archosaurs share a higher ancestral metabolic rate than that of extant ectotherms, and that this derived high metabolic rate was acquired at a much more inclusive level of the phylogenetic tree, among non-archosaurian archosauromorphs. These results also highlight the difficulties of assigning a given heat production strategy (i.e., endothermy, ectothermy) to an estimated metabolic rate value, and confirm findings of previous studies that the definition of the endotherm/ectotherm dichotomy may be ambiguous. © The Author(s) 2016. Published by Oxford University Press, on behalf of the Society of Systematic Biologists. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. High Data Rate Optical Wireless Communications Based on Ultraviolet Band

    KAUST Repository

    Sun, Xiaobin

    2017-10-01

    Optical wireless communication systems based on ultraviolet (UV)-band has a lot inherent advantages, such as low background solar radiation, low device dark noise. Besides, it also has small restrictive requirements for PAT (pointing, acquisition, and tracking) because of its high atmospheric scattering with molecules and aerosols. And these advantages are driving people to explore and utilize UV band for constructing and implementing a high-data-rate, less PAT communication links, such as diffuse-line-of-sight links (diffuse-LOS) and non-line-of-sight (NLOS). The responsivity of the photodetector at UV range is far lower than that of visible range, high power UV transmitters which can be easily modulated are under investigation. These factors make it is hard to realize a high-data-rate diffuse-LOS or NLOS UV communication links. To achieve a UV link mentioned above with current devices and modulation schemes, this thesis presents some efficient modulation schemes and available devices for the time being. Besides, a demonstration of ultraviolet-B (UVB) communication link is implemented utilizing quadrature amplitude modulation (QAM) orthogonal frequency-division multiplexing (OFDM). The demonstration is based on a 294-nm UVB-light-emitting-diode (UVB-LED) with a full-width at half-maximum (FWHM) of 9 nm, and according to the measured L-I-V curve, we set the bias voltage as 7V for maximum the ac amplitude and thus get a high signal-noise-ratio (SNR) channel, and the light output power is 190 μW with such bias voltage. Besides, there is a unique silica gel lens on top of the LED to concentrate the beam. A -3-dB bandwidth of 29 MHz was measured and a high-speed near-solar-blind communication link with a data rate of 71 Mbit/s was achieved using 8-QAM-OFDM at perfect alignment, and 23.6 Mbit/s using 2-QAM-OFDM when the angle subtended by the pointing direction of the UVB-LED and photodetector (PD) is 12 degrees, thus establishing a diffuse-line-of-sight (LOS) link

  11. High-Rate Performance of Muon Drift Tube Detectors

    CERN Document Server

    Schwegler, Philipp

    The Large Hadron Collider (LHC) at the European Centre for Particle Physics, CERN, collides protons with an unprecedentedly high centre-of-mass energy and luminosity. The collision products are recorded and analysed by four big experiments, one of which is the ATLAS detector. In parallel with the first LHC run from 2009 to 2012, which culminated in the discovery of the last missing particle of the Standard Model of particle physics, the Higgs boson, planning of upgrades of the LHC for higher instantaneous luminosities (HL-LHC) is already progressing. The high instantaneous luminosity of the LHC puts high demands on the detectors with respect to radiation hardness and rate capability which are further increased with the luminosity upgrade. In this thesis, the limitations of the Muon Drift Tube (MDT) chambers of the ATLAS Muon Spectrometer at the high background counting rates at the LHC and performance of new small diameter muon drift tube (sMDT) detectors at the even higher background rates at HL-LHC are stud...

  12. Dynamic High-Temperature Characterization of an Iridium Alloy in Compression at High Strain Rates

    Energy Technology Data Exchange (ETDEWEB)

    Song, Bo [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Experimental Environment Simulation Dept.; Nelson, Kevin [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Mechanics of Materials Dept.; Lipinski, Ronald J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Advanced Nuclear Fuel Cycle Technology Dept.; Bignell, John L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Structural and Thermal Analysis Dept.; Ulrich, G. B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Radioisotope Power Systems Program; George, E. P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Radioisotope Power Systems Program

    2014-06-01

    Iridium alloys have superior strength and ductility at elevated temperatures, making them useful as structural materials for certain high-temperature applications. However, experimental data on their high-temperature high-strain-rate performance are needed for understanding high-speed impacts in severe elevated-temperature environments. Kolsky bars (also called split Hopkinson bars) have been extensively employed for high-strain-rate characterization of materials at room temperature, but it has been challenging to adapt them for the measurement of dynamic properties at high temperatures. Current high-temperature Kolsky compression bar techniques are not capable of obtaining satisfactory high-temperature high-strain-rate stress-strain response of thin iridium specimens investigated in this study. We analyzed the difficulties encountered in high-temperature Kolsky compression bar testing of thin iridium alloy specimens. Appropriate modifications were made to the current high-temperature Kolsky compression bar technique to obtain reliable compressive stress-strain response of an iridium alloy at high strain rates (300 – 10000 s-1) and temperatures (750°C and 1030°C). Uncertainties in such high-temperature high-strain-rate experiments on thin iridium specimens were also analyzed. The compressive stress-strain response of the iridium alloy showed significant sensitivity to strain rate and temperature.

  13. Mechanical characterization of rocks at high strain rate

    Directory of Open Access Journals (Sweden)

    Konstantinov A.

    2012-08-01

    Full Text Available The paper presents the dynamic characterization in tension and compression of three rocks, Carrara marble, Onsernone gneiss and Peccia Marble, at high strain-rates. Two versions of a Split Hopkinson Bar have been used. The version for direct tension tests is installed at the DynaMat Laboratory of the University of Applied Sciences of Southern Switzerland, while the traditional version in compression is installed at the Laboratory of Dynamic Investigation of Materials of Lobachevsky State University. Results of the tests show a significantly strain-rate sensitive behaviour, exhibiting dynamic strength increasing with strain-rate. The experimental research has been developed in the frame of the Swiss-Russian Joint Research Program.

  14. High freight rates hinder oil markets' return to equilibrium

    International Nuclear Information System (INIS)

    Anon

    2005-01-01

    Hurricane damage to refineries in the US has created shortages of refined products there, boosting imports and sending freight rates across the Atlantic to record levels. The situation was made worse for a time by a strike at France's main oil terminals in the Mediterranean, which prevented some oil tankers from being rapidly redeployed to routes across the Atlantic. Worldscale (WS) rates for routes from the UK and Europe to the US Atlantic and Gulf Coasts rose well above WS500 for clean tonnage during October. High rates were nevertheless not simply confined to product tankers crossing the Atlantic. Rates for crude tankers to the US have also risen, and tightness has begun to appear in some other markets as well. The net result has been to slow down the movement of oil from regions of surplus to those of scarcity, depressing prices in the former and keeping them at high levels in the latter. Atlantic tanker markets look like remaining tight for the rest of the year and perhaps beyond. (author)

  15. Investigation of high-rate lithium-thionyl chloride cells

    Science.gov (United States)

    Hayes, Catherine A.; Gust, Steven; Farrington, Michael D.; Lockwood, Judith A.; Donaldson, George J.

    Chemical analysis of a commercially produced high-rate D-size lithium-thionyl cell was carried out, as a function of rate of discharge (1 ohm and 5 ohms), depth of discharge, and temperature (25 C and -40 C), using specially developed methods for identifying suspected minor cell products or impurities which may effect cell performance. These methods include a product-retrieval system which involves solvent extraction to enhance the recovery of suspected semivolatile minor chemicals, and methods of quantitative GC analysis of volatile and semivolatile products. The nonvolatile products were analyzed by wet chemical methods. The results of the analyses indicate that the predominant discharge reaction in this cell is 4Li + 2SOCl2 going to 4LiCl + S + SO2, with SO2 formation decreasing towards the end of cell life (7 to 12 Ah). The rate of discharge had no effect on the product distribution. Upon discharge of the high-rate cell at -40 C, one cell exploded, and all others exhibited overheating and rapid internal pressure rise when allowed to warm up to room temperature.

  16. Development of amplifier and shaper for high-rate MWPC

    International Nuclear Information System (INIS)

    Kamiji, Ichinori; Nanjo, Hajime; Kawasaki, Naoki; Maeda, Yosuke; Naito, Daichi; Seki, Shigeto; Nakagiri, Kota; Sasao, Noboru; Nomura, Tadashi

    2015-01-01

    A multi-wire proportional chamber (MWPC) will be used as an in-beam charged particle detector for the J-PARC E14 (KOTO) experiment. The maximum counting rate of the MWPC is expected to be up to 1 MHz per channel due to the high neutron and photon flux, expected to be 1 GHz for the 30 x 30 cm"2 area. An amplifier to cope with such high counting-rate is required. We developed a prototype of such amplifier, which has a charge preamplifier with the integration time of 3 ns and a pulse shaping part with three pole-zero cancellation networks. The shaper reduced the characteristic long tail lasting tens of microseconds in the signal of MWPC to 150 ns. Its performance has been tested by using a single-channel MWPC which has almost the same geometrical parameters as the MWPC to be installed in the KOTO experiment. (author)

  17. Characteristics of Multiplexed Grooved Nozzles for High Flow Rate Electrospray

    International Nuclear Information System (INIS)

    Kim, Kyoung Tae; Kim, Woo Jin; Kim, Sang Soo

    2007-01-01

    The electrospray operated in the cone-jet mode can generate highly charged micro droplets in an almost uniform size at flow rates. Therefore, the multiplexing system which can retain the characteristics of the cone-jet mode is inevitable for the electrospray application. This experiment reports the multiplexed grooved nozzle system with the extractor. The effects of the grooves and the extractor on the performance of the electrospray were evaluated through experiments. Using the grooved nozzle, the stable cone-jet mode can be achieved at the each groove in the grooved mode. Furthermore, the number of nozzles per unit area is increased by the extractor. The multiplexing density is 12 jets per cm 2 at 30 mm distance from the nozzle tip to the ground plate. The multiplexing system for the high flow rate electrospray is realized with the extractor which can diminish the space charge effect without sacrificing characteristics of the cone-jet mode

  18. Personality predicts drop-out from therapist-guided internet-based cognitive behavioural therapy for eating disorders. Results from a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Louise Högdahl

    2016-09-01

    Full Text Available Internet-based guided self-help cognitive behavioural therapy (ICBT seems a promising way of delivering eating disorder treatment. However, treatment drop-out is a common problem and little is known about the correlates, especially in clinical settings. The study aimed to explore prediction of drop-out in the context of a randomized controlled trial within specialized eating disorder care in terms of eating disorder symptomatology, personality traits, comorbidity, and demographic characteristics. 109 outpatients diagnosed with bulimia nervosa or similar eating disorder were randomized to two types of ICBT. Participants were assessed with several clinical- and self-ratings. The average drop-out rate was 36%. Drop-out was predicted by lower scores in the personality traits Dutifulness and Assertiveness as measured by the NEO Personality Inventory Revised, and by higher scores in Self-affirm as measured by the Structural Analysis of Social Behaviour. Drop-out was also predicted by therapist factors: one therapist had significantly more drop-outs (82% than the other three (M = 30%. Theoretical and clinical implications of the impact of the predictors are discussed.

  19. Lost without trace: oximetry signal dropout in preterm infants.

    Science.gov (United States)

    Lim, Kathleen; Wheeler, Kevin I; Jackson, Hamish D; Sadeghi Fathabadi, Omid; Gale, Timothy J; Dargaville, Peter A

    2015-09-01

    Oxygen saturation (SpO2) signal dropout leaves caregivers without a reliable measure to guide oxygen therapy. We studied SpO2 dropout in preterm infants on continuous positive airway pressure, noting the SpO2 values at signal loss and recovery and thus the resultant change in SpO2, and the factors influencing this parameter. In 32 infants of median gestation 26 weeks, a total of 3932 SpO2 dropout episodes were identified (1.1 episodes/h). In the episodes overall, SpO2 decreased by 1.1%, with the SpO2 change influenced by starting SpO2 (negative correlation), but not dropout duration. For episodes starting in hypoxia (SpO2 dropout, with a downward trajectory in a quarter of cases. We conclude that after signal dropout SpO2 generally recovers in a relative normoxic range. Blind FiO2 adjustments are thus unlikely to be of benefit during most SpO2 dropout episodes. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  20. Miniaturized Stretchable and High-Rate Linear Supercapacitors

    OpenAIRE

    Zhu, Wenjun; Zhang, Yang; Zhou, Xiaoshuang; Xu, Jiang; Liu, Zunfeng; Yuan, Ningyi; Ding, Jianning

    2017-01-01

    Linear stretchable supercapacitors have attracted much attention because they are well suited to applications in the rapidly expanding field of wearable electronics. However, poor conductivity of the electrode material, which limits the transfer of electrons in the axial direction of the linear supercapacitors, leads to a serious loss of capacity at high rates. To solve this problem, we use gold nanoparticles to decorate aligned multiwall carbon nanotube to fabricate stretchable linear electr...