Pedagogical Differences during a Science and Language Intervention for English Language Learners

ERIC Educational Resources Information Center

Garza, Tiberio; Huerta, Margarita; Lara-Alecio, Rafael; Irby, Beverly J.; Tong, Fuhui

2018-01-01

The purpose of this study was to compare and describe 8 fifth-grade classrooms by their teachers pedagogy during a quasiexperimental, longitudinal, and field-based project focused on increasing English language learners' (ELLs') achievement in science and language. The larger study found statistically significant and positive intervention effects…

A Retest of Two HIV Disclosure Theories: The Women's Story

ERIC Educational Resources Information Center

Serovich, Julianne M.; Lim, Ji-Young; Mason, Tina L.

2008-01-01

The purpose of this study was to evaluate the applicability of two theories of HIV disclosure previously tested with men. Participants included 125 HIV-positive women enrolled in a larger, longitudinal study of HIV disclosure and mental health. Structural equation modeling was used to analyze the proposed theoretical models. The disease…

Common Belief and the Cultural Curriculum: An Intergenerational Study of Historical Consciousness

ERIC Educational Resources Information Center

Wineburg, Sam; Mosborg, Susan; Porat, Dan; Duncan, Ariel

2007-01-01

How is historical knowledge transmitted across generations? What is the role of schooling in that transmission? The authors address these questions by reporting on a thirty-month longitudinal study into how home, school, and larger society served as contexts for the development of historical consciousness among adolescents. Fifteen families drawn…

Sustained Attention Development during the Toddlerhood to Preschool Period: Associations with Toddlers' Emotion Regulation Strategies and Maternal Behaviour

ERIC Educational Resources Information Center

Graziano, Paulo A.; Calkins, Susan D.; Keane, Susan P.

2011-01-01

The current study examined the role of maternal behaviour and toddlers' emotion regulation strategies in the development of children's sustained attention abilities. Participants for this study included 447 children (232 girls) obtained from three different cohorts participating in a larger ongoing longitudinal study. When the children were 2…

Administrator Observation and Feedback: Does It Lead toward Improvement in Inquiry-Oriented Math Instruction?

ERIC Educational Resources Information Center

Rigby, Jessica G.; Larbi-Cherif, Adrian; Rosenquist, Brooks A.; Sharpe, Charlotte J.; Cobb, Paul; Smith, Thomas

2017-01-01

Purpose: This study examines the content and efficacy of instructional leaders' expectations and feedback (press) in relation to the improvement of middle school mathematics teachers' instruction in the context of coherent systems of supports. Research Method/Approach: This mixed methods study is a part of a larger, 8-year longitudinal study in…

Simultaneous maximum a posteriori longitudinal PET image reconstruction

NASA Astrophysics Data System (ADS)

Ellis, Sam; Reader, Andrew J.

2017-09-01

Positron emission tomography (PET) is frequently used to monitor functional changes that occur over extended time scales, for example in longitudinal oncology PET protocols that include routine clinical follow-up scans to assess the efficacy of a course of treatment. In these contexts PET datasets are currently reconstructed into images using single-dataset reconstruction methods. Inspired by recently proposed joint PET-MR reconstruction methods, we propose to reconstruct longitudinal datasets simultaneously by using a joint penalty term in order to exploit the high degree of similarity between longitudinal images. We achieved this by penalising voxel-wise differences between pairs of longitudinal PET images in a one-step-late maximum a posteriori (MAP) fashion, resulting in the MAP simultaneous longitudinal reconstruction (SLR) method. The proposed method reduced reconstruction errors and visually improved images relative to standard maximum likelihood expectation-maximisation (ML-EM) in simulated 2D longitudinal brain tumour scans. In reconstructions of split real 3D data with inserted simulated tumours, noise across images reconstructed with MAP-SLR was reduced to levels equivalent to doubling the number of detected counts when using ML-EM. Furthermore, quantification of tumour activities was largely preserved over a variety of longitudinal tumour changes, including changes in size and activity, with larger changes inducing larger biases relative to standard ML-EM reconstructions. Similar improvements were observed for a range of counts levels, demonstrating the robustness of the method when used with a single penalty strength. The results suggest that longitudinal regularisation is a simple but effective method of improving reconstructed PET images without using resolution degrading priors.

Longitudinal development of muons in large air showers studies from the arrival time distributions measured at 900m above sea level

NASA Technical Reports Server (NTRS)

Kakimoto, F.; Tsuchimoto, I.; Enoki, T.; Suga, K.; Nishi, K.

1985-01-01

The arrival time distributions of muons with energies above 1.0GeV and 0.5GeV have been measured in the Akeno air-shower array to study the longitudinal development of muons in air showers with primary energies in the range 10 to the 17th power to 10 to the 18th power ev. The average rise times of muons with energies above 1.0GeV at large core distances are consistent with those expected from very high multiplicity models and, on the contrary, with those expected from the low multiplicity models at small core distances. This implies that the longitudinal development at atmospheric depth smaller than 500 cm square is very fast and that at larger atmospheric depths is rather slow.

Spatial correlation of atmospheric wind at scales relevant for large scale wind turbines

NASA Astrophysics Data System (ADS)

Bardal, L. M.; Sætran, L. R.

2016-09-01

Wind measurements a short distance upstream of a wind turbine can provide input for a feedforward wind turbine controller. Since the turbulent wind field will be different at the point/plane of measurement and the rotor plane the degree of correlation between wind speed at two points in space both in the longitudinal and lateral direction should be evaluated. This study uses a 2D array of mast mounted anemometers to evaluate cross-correlation of longitudinal wind speed. The degree of correlation is found to increase with height and decrease with atmospheric stability. The correlation is furthermore considerably larger for longitudinal separation than for lateral separation. The integral length scale of turbulence is also considered.

Longitudinal association between television watching and computer use and risk markers in diabetes in the SEARCH for Diabetes in Youth Study

PubMed Central

Li, Chao; Beech, Bettina; Crume, Tessa; D’Agostino, Ralph B.; Dabelea, Dana; Kaar, Jill L; Liese, Angela D.; Mayer-Davis, Elizabeth J.; Pate, Russell; Pettitt, David J.; Taplin, Craig; Rodriguez, Beatriz; Merchant, Anwar T.

2014-01-01

Background The study provides evidence of the longitudinal association between screen time with hemoglobin A1c and cardiovascular risk markers among youth with type 1 (T1D) and type 2 diabetes (T2D) . Objective To examine the longitudinal relationship of screen time with HbA1c and serum lipids among youth with diabetes. Subjects Youth with T1D and T2D. Methods We followed up 1049 youth (≥10 yr. old) with recently diagnosed T1D and T2D participating in the SEARCH for Diabetes in Youth Study. Results Increased television watching on weekdays and during the week over time was associated with larger increases in HbA1c among youth with T1D and T2D (p-value<0.05). Among youth with T1D, significant longitudinal associations were observed between television watching and TG (p-value<0.05) (week days and whole week), and LDL-c (p-value<0.05) (whole week). For example, for youth who watched 1 hour of television per weekday at the outset and 3 hours per weekday 5 years later, the longitudinal model predicted greater absolute increases in HbA1c (2.19% for T1D and 2.16% for T2D); whereas for youth who watched television 3 hours per weekday at the outset and 1 hour per weekday 5 years later, the model predicted lesser absolute increases in HbA1c (2.08% for T1D and 1.06% for T2D). Conclusions Youth with T2D who increased their television watching over time vs those that decreased it had larger increases in HbA1c over 5 years. Youth with T1D who increased their television watching over time had increases in LDL-c, TG and to a lesser extent HbA1c . PMID:25041407

Longitudinal Brain Magnetic Resonance Imaging CO2 Stress Testing in Individual Adolescent Sports-Related Concussion Patients: A Pilot Study.

PubMed

Mutch, W Alan C; Ellis, Michael J; Ryner, Lawrence N; Morissette, Marc P; Pries, Philip J; Dufault, Brenden; Essig, Marco; Mikulis, David J; Duffin, James; Fisher, Joseph A

2016-01-01

Advanced neuroimaging studies in concussion have been limited to detecting group differences between concussion patients and healthy controls. In this small pilot study, we used brain magnetic resonance imaging (MRI) CO2 stress testing to longitudinally assess cerebrovascular responsiveness (CVR) in individual sports-related concussion (SRC) patients. Six SRC patients (three males and three females; mean age = 15.7, range = 15-17 years) underwent longitudinal brain MRI CO2 stress testing using blood oxygen level-dependent (BOLD) MRI and model-based prospective end-tidal CO2 targeting under isoxic conditions. First-level and second-level comparisons were undertaken using statistical parametric mapping (SPM) to score the scans and compare them to an atlas of 24 healthy control subjects. All tests were well tolerated and without any serious adverse events. Anatomical MRI was normal in all study participants. The CO2 stimulus was consistent between the SRC patients and control subjects and within SRC patients across the longitudinal study. Individual SRC patients demonstrated both quantitative and qualitative patient-specific alterations in CVR (p < 0.005) that correlated strongly with clinical findings, and that persisted beyond clinical recovery. Standardized brain MRI CO2 stress testing is capable of providing a longitudinal assessment of CVR in individual SRC patients. Consequently, larger prospective studies are needed to examine the utility of brain MRI CO2 stress testing as a clinical tool to help guide the evaluation, classification, and longitudinal management of SRC patients.

Ecological Fallacy in Reading Acquisition Research: Masking Constructive Processes of the Learner.

ERIC Educational Resources Information Center

Berninger, Virginia W.; Abbott, Robert D.

A study examined whether conclusions about constructive processes in reading based on analysis of group data were consistent with those based on an analysis of individual data. Subjects, selected from a larger sample of 45 first grade students who had participated in a longitudinal study on acquisition of linguistic procedures for printed words,…

Neighborhood Disorganization, Substance Use, and Violence among Adolescents in Puerto Rico

ERIC Educational Resources Information Center

Reyes, Juan C.; Robles, Rafaela R.; Colon, Hector M.; Negron, Juan; Matos, Tomas D.; Calderon, Jose; Perez, Olga M.

2008-01-01

This study investigates the role of neighborhoods in adolescent violence in poor neighborhoods in San Juan, Puerto Rico. The study is part of a larger longitudinal project examining risk and resilience in adolescents' ages 12 to 15 years old and their caregivers. Using a cross-sectional design, a self-completion questionnaire, and an interviewer…

Developing and Fostering Passion in Academic and Nonacademic Domains

ERIC Educational Resources Information Center

Fredricks, Jennifer A.; Alfeld, Corinne; Eccles, Jacquelynne

2010-01-01

The purpose of this study was to explore how passion was manifested among gifted and talent youth selected from a larger longitudinal study of child and adolescent development. The gifted sample included 25 high school and college students who were selected because they were in a gifted program in elementary school. The talent sample included 41…

Multi-Institution Study of Student Demographics and Outcomes in Electrical and Computer Engineering in the USA

ERIC Educational Resources Information Center

Lord, Susan M.; Layton, Richard A.; Ohland, Matthew W.

2015-01-01

Electrical Engineering (EE) and Computer Engineering (CpE) programs have similar curricula, but different demographics and student outcomes. This paper extends earlier longitudinal studies to a larger and more diverse dataset with 90,000 first-time-in-college and 26,000 transfer students who majored in engineering at USA institutions, including…

Graduation and Withdrawal from RN Programs. A Report of the Nurse Career-Pattern Study.

ERIC Educational Resources Information Center

Knopf, Lucille

Based on a larger longitudinal study, this document examines three nursing groups--those entering schools preparing registered nurses in 1962, 1965, and 1967. It describes and compares those who graduated and those who withdrew before graduation and examines the reasons why the students withdraw from both the students' and the program directors'…

Outcomes of On-Line Financial Education for Chronically Ill Rural Women

ERIC Educational Resources Information Center

Haynes, Deborah C.; Haynes, George W.; Weinert, Clarann

2011-01-01

This research was part of a larger longitudinal study of chronically ill rural women to determine if computer technology could be effective in allowing the women to take control of their own well-being, including finances. The current study examined whether chronically ill rural women can effectively use on-line personal finance educational…

Managing Criticism in Ph.D. Supervision: A Qualitative Case Study

ERIC Educational Resources Information Center

Li, Sarah; Seale, Clive

2007-01-01

This article is part of a larger study which presents findings from an in-depth longitudinal case study of a student's Ph.D. journey. It shows how criticism is produced and managed in the supervisory relationship. As well as an overview of types of criticism produced across a range of supervisory interactions, the article presents a micro-analysis…

Some Correlates of Child-Rearing Attitudes.

ERIC Educational Resources Information Center

Copeland, Anne P.; Barenbaum, Nicole B.

One hundred and twelve Caucasian mothers (recently separated from their husbands) and their children (6-12 years old) who were participating in a larger longitudinal study of the effects of parental divorce on families were interviewed and completed psychological measures about coping and parenting. Based on mothers' responses to a parenting…

Retinal vessel caliber among people with acquired immunodeficiency syndrome: relationships with disease-associated factors and mortality.

PubMed

Gangaputra, Sapna; Kalyani, Partho S; Fawzi, Amani A; Van Natta, Mark L; Hubbard, Larry D; Danis, Ronald P; Thorne, Jennifer E; Holland, Gary N

2012-03-01

To evaluate relationships between retinal vessel caliber, AIDS-related factors, and mortality. Longitudinal, observational cohort study. We evaluated data for participants without ocular opportunistic infections at initial examination (baseline) in the Longitudinal Studies of the Ocular Complications of AIDS (1998-2008). Semi-automated evaluation of fundus photographs (1 eye/participant) determined central retinal artery equivalent (CRAE), central retinal vein equivalent (CRVE), and arteriole-to-venule ratio (AVR) at baseline. Multiple linear regression models, using forward selection, identified independent relationships between indices and various host- and disease-related variables. Included were 1250 participants. Mean follow-up for determination of mortality was 6.1 years. Smaller CRAE was related to increased age (P < .001) and hypertension (P < .001); larger CRAE was related to lower hematocrit (P = .002). Larger CRAE and CRVE were associated with black race (P < .001). Larger CRVE was related to smoking (P = .004); smaller CRVE was related to age (P < .001) and higher mean corpuscular volume (P = .001). We observed the following relationships with AIDS-associated factors: smaller CRAE and larger CRVE with history of highly active antiretroviral therapy (HAART; P < .001); and larger CRAE with lower CD4+ T lymphocyte count (P = .04). We did not identify independent relationships with human immunodeficiency virus RNA blood levels. There was a 12% (95% CI, 2%-21%) increase in mortality risk per quartile of decreasing AVR (P = .02). Variations in retinal vascular caliber are associated with AIDS-specific factors and are markers for increased mortality risk. Relationships are consistent with the hypothesis that the vasculature is altered by known atherogenic effects of chronic HAART or the prolonged inflammatory state associated with AIDS. Copyright © 2012 Elsevier Inc. All rights reserved.

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

Gupta, Shashaank; Belianinov, Alex; Okatan, Mahmut B

(001)pc textured K0.5Na0.5NbO3 (KNN) ceramic was found to exhibit a 65% improvement in the longitudinal piezoelectric response as compared to its random counterpart. Piezoresponse force microscopy study revealed the existence of larger 180 and non-180 domains for textured ceramic as compared to that of the random ceramic. Improvement in piezoresponse by the development of (001)pc texture is discussed in terms of the crystallographic nature of KNN and domain morphology. A comparative analysis performed with a rhombohedral composition suggested that the improvement in longitudinal piezoresponse of polycrystalline ceramics by the development of (001)pc texture is limited by the crystal structure.

A longitudinal study of the relationships between the Big Five personality traits and body size perception.

PubMed

Hartmann, Christina; Siegrist, Michael

2015-06-01

The present study investigated the longitudinal development of body size perception in relation to different personality traits. A sample of Swiss adults (N=2905, 47% men), randomly selected from the telephone book, completed a questionnaire on two consecutive years (2012, 2013). Body size perception was assessed with the Contour Drawing Rating Scale and personality traits were assessed with a short version of the Big Five Inventory. Longitudinal analysis of change indicated that men and women scoring higher on conscientiousness perceived themselves as thinner one year later. In contrast, women scoring higher on neuroticism perceived their body size as larger one year later. No significant effect was observed for men scoring higher on neuroticism. These results were independent of weight changes, body mass index, age, and education. Our findings suggest that personality traits contribute to body size perception among adults. Copyright © 2015 Elsevier Ltd. All rights reserved.

Spousal interrelations in happiness in the Seattle Longitudinal Study: considerable similarities in levels and change over time.

PubMed

Hoppmann, Christiane A; Gerstorf, Denis; Willis, Sherry L; Schaie, K Warner

2011-01-01

Development does not take place in isolation and is often interrelated with close others such as marital partners. To examine interrelations in spousal happiness across midlife and old age, we used 35-year longitudinal data from both members of 178 married couples in the Seattle Longitudinal Study. Latent growth curve models revealed sizeable spousal similarities not only in levels of happiness but also in how happiness changed over time. These spousal interrelations were considerably larger in size than those found among random pairs of women and men from the same sample. Results are in line with life-span theories emphasizing an interactive minds perspective by showing that adult happiness waxes and wanes in close association with the respective spouse. Our findings also complement previous individual-level work on age-related changes in well-being by pointing to the importance of using the couple as the unit of analysis.

Quality of Parent Communication about Sex and Its Relationship to Risky Sexual Behavior among Youth in Psychiatric Care: A Pilot Study

ERIC Educational Resources Information Center

Wilson, Helen W.; Donenberg, Geri

2004-01-01

Background: The number of HIV infections among adolescents is increasing, and youth in psychiatric care are at particular risk because of their high rates of risky sexual behavior. Methods: As part of a larger longitudinal study examining AIDS-risk behavior among adolescents in psychiatric care, this pilot study investigated the relationship…

Co-Evolution of User and Organizational Interfaces: A Longitudinal Case Study of WWW Dissemination of National Statistics.

ERIC Educational Resources Information Center

Marchionini, Gary

2002-01-01

Describes how user interfaces for the Bureau of Labor Statistics (BLS) web site evolved over a 5-year period along with the larger organizational interface and how this co-evolution has influenced the institution. Interviews with BLS staff and transaction log analysis are the foci of this study, as well as user information-seeking studies and user…

Thick Explanation in the Ethnographic Study of Child Socialization: A Longitudinal Study of the Problem of Schooling for Kwara'ae (Solomon Islands) Children.

ERIC Educational Resources Information Center

Watson-Gegeo, Karen Ann

1992-01-01

Outlines a framework for examining children's socialization that combines microlevels and macrolevels. Applies the framework to a case study of student failure in the Solomon Islands. Concludes that children's failure had less to do with home socialization than with larger societal processes that shape schooling in the Solomons. (MM)

Managing Institutional and Sociocultural Challenges through Sociotransformative Constructivism: A Longitudinal Case Study of a High School Science Teacher

ERIC Educational Resources Information Center

Rodriguez, Alberto J.

2015-01-01

Using a case study approach, this manuscript describes the professional transformation of Gary--an Anglo, male novice teacher--by focusing on his first two years of teaching in a culturally diverse and economically disadvantaged school. As a participant of a larger hybrid, intervention project with peers, Gary received multiple hands-on and…

The Effects of Prematurity and Illness on Parents' Perceptions of Their Infants.

ERIC Educational Resources Information Center

Danko, Maribeth; And Others

Part of a larger study investigating the longitudinal effects of prematurity, illness, and hospitalization, this study focuses on parent perceptions of their infants at 2, 4, and 6 months of age, with age being corrected for conceptional age at birth. It was hypothesized that neonatal condition and age of infant at the time of measurement would…

The Course and Outcome of Psychiatric Illness in People with Prader-Willi Syndrome: Implications for Management and Treatment

ERIC Educational Resources Information Center

Soni, S.; Whittington, J.; Holland, A. J.; Webb, T.; Maina, E.; Boer, H.; Clarke, D.

2007-01-01

Background: This study is part of a larger UK-wide study investigating psychiatric illness in people with Prader-Willi syndrome (PWS), and describes the longitudinal aspect of psychiatric illness, in particular psychotic illness, and examines the use and role of psychotropic medication. Method: A total of 119 individuals with genetically confirmed…

Do Gains in Test Scores Explain Labor Market Outcomes?

ERIC Educational Resources Information Center

Rose, Heather

2006-01-01

Using data from the National Education Longitudinal Study of 1988, this article investigates whether students who made relatively large test score gains during high school had larger earnings 7 years after high school compared to students whose scores improved little. In models that control for pre-high school test scores, family background, and…

Development of Fraction Comparison Strategies: A Latent Transition Analysis

ERIC Educational Resources Information Center

Rinne, Luke F.; Ye, Ai; Jordan, Nancy C.

2017-01-01

The present study investigated the development of fraction comparison strategies through a longitudinal analysis of children's responses to a fraction comparison task in 4th through 6th grades (N = 394). Participants were asked to choose the larger value for 24 fraction pairs blocked by fraction type. Latent class analysis of performance over item…

A Family Life-Cycle Approach to the Socioeconomic Attainment of Working Women.

ERIC Educational Resources Information Center

Hanson, Sandra L.

1983-01-01

Examined married women's (N=453) social and economic labor market attainments from a family life-cycle perspective using a longitudinal study. Findings suggest that the effects of early family experiences on attainment are larger and more permanent than those of later family experiences and actually increase over time. (Author/JAC)

Spousal Caregiver Narratives and Credible Authority: Uncertainty in Illness of Spousal Caregivers

ERIC Educational Resources Information Center

Sodowsky, Karen

2012-01-01

This article is taken from a larger longitudinal study that used caregiver interviews, caregiver surveys, and caregiver statistical information of one community. The interviews were conducted with six spousal caregivers to examine the narratives produced by spouses actively caring for their partners with dementia. The spousal caregivers were…

Successful Students' Negotiation of Township Schooling in Contemporary South Africa

ERIC Educational Resources Information Center

Kapp, Rochelle; Badenhorst, Elmi; Bangeni, Bongi; Craig, Tracy S.; van Rensburg, Viki Janse; Le Roux, Kate; Prince, Robert; Pym, June; van Pletzen, Ermien

2014-01-01

This article draws on data from a larger longitudinal qualitative case study which is tracking the progress of students over the course of their undergraduate degrees at a South African university. For this paper, we used background questionnaires and semi-structured interviews with 62 first-year students from working-class, township schools who…

Predicting First-Grade Reading Performance from Kindergarten Response to Tier 1 Instruction

ERIC Educational Resources Information Center

Al Otaiba, Stephanie; Folsom, Jessica S.; Schatschneider, Christopher; Wanzek, Jeanne; Greulich, Luana; Meadows, Jane; Li, Zhi; Connor, Carol M.

2011-01-01

Many schools are implementing multitier response-to-intervention (RTI) models to reduce reading difficulties. This study was part of our larger ongoing longitudinal RTI investigation within the Florida Learning Disabilities Center grant and was conducted in 7 ethnically and socioeconomically diverse schools. We observed reading instruction in 20…

Simplified Aircraft-Based Paired Approach: Concept Definition and Initial Analysis

NASA Technical Reports Server (NTRS)

Johnson, Sally C.; Lohr, Gary W.; McKissick, Burnell T.; Abbott, Terence S.; Geurreiro, Nelson M.; Volk, Paul

2013-01-01

Simplified Aircraft-based Parallel Approach (SAPA) is an advanced concept proposed by the Federal Aviation Administration (FAA) to support dependent parallel approach operations to runways with lateral spacing closer than 2500 ft. At the request of the FAA, NASA performed an initial assessment of the potential performance and feasibility of the SAPA concept, including developing and assessing an operational implementation of the concept and conducting a Monte Carlo wake simulation study to examine the longitudinal spacing requirements. The SAPA concept was shown to have significant operational advantages in supporting the pairing of aircraft with dissimilar final approach speeds. The wake simulation study showed that support for dissimilar final approach speeds could be significantly enhanced through the use of a two-phased altitudebased longitudinal positioning requirement, with larger longitudinal positioning allowed for higher altitudes out of ground effect and tighter longitudinal positioning defined for altitudes near and in ground effect. While this assessment is preliminary and there are a number of operational issues still to be examined, it has shown the basic SAPA concept to be technically and operationally feasible.

Nutrition in transition: dietary patterns of rural Amazonian women during a period of economic change.

PubMed

Piperata, Barbara A; Ivanova, Sofia A; Da-gloria, Pedro; Veiga, Gonçalo; Polsky, Analise; Spence, Jennifer E; Murrieta, Rui S S

2011-01-01

The goal of this study was to understand the relationship between economic change (wage labor, retirement, and the Bolsa Família program) and dietary patterns in the rural Amazon and to determine the extent to which these changes followed the pattern of the nutrition transition. The study was longitudinal. The weighed-inventory method and economic interviews were used to collect data on dietary intake and household economics in a sample of 30 and 52 women in 2002 and 2009, respectively. Twenty of the women participated in both years and make-up the longitudinal sub-sample. Comparative statistics were used to identify changes in dietary patterns over time and multiple linear regressions were used to explore the relationship between economics, subsistence strategies, and diet. There was a significant decline in kcal (P < 0.01) and carbohydrate (P < 0.01) but no change in protein intake over time in both the larger and smaller, longitudinal subsample. The percent of energy, carbohydrate, protein, and fat purchased increased in the larger and longitudinal samples (P ≤ 0.02) and there was an increase in refined carbohydrate and processed, fatty-meat consumption over time. The abandonment of manioc gardens was associated with increased dependence on purchased food (P = 0.03) while receipt of the Bolsa Família was associated with increased protein intake and adequacy (P = 0.02). The dietary changes observed are only in partial agreement with predictions of the nutrition transition literature. The relationship between the economic and diet changes was shaped by the local context which should be considered when implementing CCT programs, like the Bolsa Família. Copyright © 2011 Wiley-Liss, Inc.

State and trait effects on individual differences in children's mathematical development.

PubMed

Bailey, Drew H; Watts, Tyler W; Littlefield, Andrew K; Geary, David C

2014-11-01

Substantial longitudinal relations between children's early mathematics achievement and their much later mathematics achievement are firmly established. These findings are seemingly at odds with studies showing that early educational interventions have diminishing effects on children's mathematics achievement across time. We hypothesized that individual differences in children's later mathematical knowledge are more an indicator of stable, underlying characteristics related to mathematics learning throughout development than of direct effects of early mathematical competency on later mathematical competency. We tested this hypothesis in two longitudinal data sets, by simultaneously modeling effects of latent traits (stable characteristics that influence learning across time) and states (e.g., prior knowledge) on children's mathematics achievement over time. Latent trait effects on children's mathematical development were substantially larger than state effects. Approximately 60% of the variance in trait mathematics achievement was accounted for by commonly used control variables, such as working memory, but residual trait effects remained larger than state effects. Implications for research and practice are discussed. © The Author(s) 2014.

State and Trait Effects on Individual Differences in Children's Mathematical Development

PubMed Central

Bailey, Drew H.; Watts, Tyler W.; Littlefield, Andrew K.; Geary, David C.

2015-01-01

Substantial longitudinal relations between children's early mathematics achievement and their much later mathematics achievement are firmly established. These findings are seemingly at odds with studies showing that early educational interventions have diminishing effects on children's mathematics achievement across time. We hypothesized that individual differences in children's later mathematical knowledge are more an indicator of stable, underlying characteristics related to mathematics learning throughout development than of direct effects of early mathematical competency on later mathematical competency. We tested this hypothesis in two longitudinal data sets, by simultaneously modeling effects of latent traits (stable characteristics that influence learning across time) and states (e.g., prior knowledge) on children's mathematics achievement over time. Latent trait effects on children's mathematical development were substantially larger than state effects. Approximately 60% of the variance in trait mathematics achievement was accounted for by commonly used control variables, such as working memory, but residual trait effects remained larger than state effects. Implications for research and practice are discussed. PMID:25231900

Longitudinal mediation of processing speed on age-related change in memory and fluid intelligence.

PubMed

Robitaille, Annie; Piccinin, Andrea M; Muniz-Terrera, Graciela; Hoffman, Lesa; Johansson, Boo; Deeg, Dorly J H; Aartsen, Marja J; Comijs, Hannie C; Hofer, Scott M

2013-12-01

Age-related decline in processing speed has long been considered a key driver of cognitive aging. While the majority of empirical evidence for the processing speed hypothesis has been obtained from analyses of between-person age differences, longitudinal studies provide a direct test of within-person change. Using recent developments in longitudinal mediation analysis, we examine the speed-mediation hypothesis at both the within-and between-person levels in two longitudinal studies, Longitudinal Aging Study Amsterdam (LASA) and Origins of Variance in the Oldest-Old (OCTO-Twin). We found significant within-person indirect effects of change in age, such that increasing age was related to lower speed, which in turn relates to lower performance across repeated measures on other cognitive outcomes. Although between-person indirect effects were also significant in LASA, they were not in OCTO-Twin which is not unexpected given the age homogeneous nature of the OCTO-Twin data. A more in-depth examination through measures of effect size suggests that, for the LASA study, the within-person indirect effects were small and between-person indirect effects were consistently larger. These differing magnitudes of direct and indirect effects across levels demonstrate the importance of separating between- and within-person effects in evaluating theoretical models of age-related change. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Three-dimensional envelope instability in periodic focusing channels

NASA Astrophysics Data System (ADS)

Qiang, Ji

2018-03-01

The space-charge driven envelope instability can be of great danger in high intensity accelerators and was studied using a two-dimensional (2D) envelope model and three-dimensional (3D) macroparticle simulations before. In this paper, we study the instability for a bunched beam using a three-dimensional envelope model in a periodic solenoid and radio-frequency (rf) focusing channel and a periodic quadrupole and rf focusing channel. This study shows that when the transverse zero current phase advance is below 90 ° , the beam envelope can still become unstable if the longitudinal zero current phase advance is beyond 90 ° . For the transverse zero current phase advance beyond 90 ° , the instability stopband width becomes larger with the increase of the longitudinal focusing strength and even shows different structure from the 2D case when the longitudinal zero current phase advance is beyond 90 ° . Breaking the symmetry of two longitudinal focusing rf cavities and the symmetry between the horizontal focusing and the vertical focusing in the transverse plane in the periodic quadrupole and rf channel makes the instability stopband broader. This suggests that a more symmetric accelerator lattice design might help reduce the range of the envelope instability in parameter space.

Communication Competence, Psychological Well-being, and the Mediating Role of Coping Efforts among Women with Breast Cancer: Cross-sectional and Longitudinal Evidence

PubMed Central

Shim, Minsun; Mercer Kollar, Laura M.; Roberts, Linda; Gustafson, David

2015-01-01

Despite existing research identifying psychological benefits of patients’ interpersonal competence in various contexts, little longitudinal research has addressed underlying mechanism(s). To address this limitation, we examined both the cross-sectional and longitudinal associations between cancer patients’ communication competence in close relationships and psychological well-being, as well as the mediating role of coping efforts. Data came from a larger project with women with breast cancer (N = 661), recruited from April 2005 to May 2007 at three large university-affiliated cancer centers in the U.S. to study the effects of an Internet-based system providing patients and families with a range of services. The present study focused on survey data at baseline, 6 weeks, and 12 weeks after the intervention (controlling for the possible effects of the intervention). Results from both cross-sectional and longitudinal analyses indicated that competence in open communication between patients and their close support persons had a positive association with patients’ psychological well-being and that approach coping efforts partially mediated this association. We discussed the implications and limitations of the study. PMID:25793748

Continuity of Genetic and Environmental Influences on Cognition across the Life Span: A Meta-Analysis of Longitudinal Twin and Adoption Studies

PubMed Central

Tucker-Drob, Elliot M.; Briley, Daniel A.

2014-01-01

The longitudinal rank-order stability of cognitive ability increases dramatically over the lifespan. Multiple theoretical perspectives have proposed that genetic and/or environmental mechanisms underlie the longitudinal stability of cognition, and developmental trends therein. However, the patterns of stability of genetic and environmental influences on cognition over the lifespan largely remain poorly understood. We searched for longitudinal studies of cognition that reported raw genetically-informative longitudinal correlations or parameter estimates from longitudinal behavior genetic models. We identified 150 combinations of time points and measures from 15 independent longitudinal samples. In total, longitudinal data came from 4,538 monozygotic twin pairs raised together, 7,777 dizygotic twin pairs raised together, 34 monozygotic twin pairs raised apart, 78 dizygotic twin pairs raised apart, 141 adoptive sibling pairs, and 143 non-adoptive sibling pairs, ranging in age from infancy through late adulthood. At all ages, cross-time genetic correlations and shared environmental correlations were substantially larger than cross-time nonshared environmental correlations. Cross-time correlations for genetic and shared environmental components were low during early childhood, increased sharply over child development, and remained relatively high from adolescence through late adulthood. Cross-time correlations for nonshared environmental components were low across childhood and increased gradually to moderate magnitudes in adulthood. Increasing phenotypic stability over child development was almost entirely mediated by genetic factors. Time-based decay of genetic and shared environmental stability was more pronounced earlier in child development. Results are interpreted in reference to theories of gene-environment interaction and correlation. PMID:24611582

Longitudinal patterns of employment and postsecondary education for adults with autism and average-range IQ

PubMed Central

Taylor, Julie Lounds; Henninger, Natalie A.; Mailick, Marsha R.

2015-01-01

This study examined correlates of participation in postsecondary education (PSE) and employment over 12 years for 73 adults with autism spectrum disorders (ASD) and average-range IQ whose families were part of a larger, longitudinal study. Correlates included demographic (sex, maternal education, paternal education), behavioral (activities of daily living, maladaptive behaviors, autism symptoms) and family (size of maternal social network; maternal depressive symptoms, anxiety, and pessimism) factors. Although two-thirds of adults with ASD participated in competitive employment/PSE during the study, fewer than 25% maintained these activities over the study period. Behavioral characteristics distinguished those who never had competitive employment/PSE from those who sometimes or consistently participated in these activities. Women were considerably less likely than men to maintain employment/PSE over time. PMID:26019306

The Effects of Family Characteristics and Time Use on Teenagers' Household Labor.

ERIC Educational Resources Information Center

Gager, Constance T.; Cooney, Teresa M.; Call, Kathleen Thiede

1999-01-01

Longitudinal data collected from teenagers were analyzed for types of household chores the teens perform. The study determined that girls devoted more time to household tasks than boys, while both their efforts were greater in larger families and single-parent families. High school males spent more time on extracurricular and leisure activities,…

Unpacking Understanding: The (Re)search for the Holy Grail of Mathematics Education

ERIC Educational Resources Information Center

Llewellyn, Anna

2012-01-01

In this article, I deconstruct the concept of understanding in mathematics education, examining how it is spoken into being and what work it does for primary school student teachers. I use poststructural analysis to unpack interviews with a student teacher, Jane, drawn from a larger longitudinal study. I show how she negotiates tensions between…

Longitudinal Follow-up of Autism Spectrum Features and Sensory Behaviors in Angelman Syndrome by Deletion Class

ERIC Educational Resources Information Center

Peters, Sarika U.; Horowitz, Lucia; Barbieri-Welge, Rene; Taylor, Julie Lounds; Hundley, Rachel J.

2012-01-01

Background: Angelman syndrome (AS) is a neurogenetic disorder characterized by severe intellectual disability, lack of speech, and low threshold for laughter; it is considered a "syndromic" form of autism spectrum disorder (ASD). Previous studies have indicated overlap of ASD and AS, primarily in individuals with larger (approximately 6 Mb) Class…

Career and Education Patterns of Rural Women.

ERIC Educational Resources Information Center

Lichtman, Marilyn; Rothschild, Susan J. S.

Data drawn from the National Longitudinal Study of the High School Class of 1972 and follow-up surveys through 1979 were used to explore career and educational patterns of two groups of women: those who received their high school education in rural areas and remained, and those who left for larger communities. Over 40% of the sample were…

The Cognitive Contribution to the Development of Proficiency in a Foreign Language

ERIC Educational Resources Information Center

Csapo, Beno; Nikolov, Marianne

2009-01-01

The present paper reports results of a longitudinal research project studying the contribution of cognitive skills and other factors to proficiency in a foreign language (L2) in the Hungarian educational context. The larger project aims to describe the levels of L2 proficiency of school-aged populations in order to explore the conditions and…

Children's Executive Function and High-Calorie, Low-Nutrient Food Intake: Mediating Effects of Child-Perceived Adult Fast Food Intake

ERIC Educational Resources Information Center

Tate, Eleanor B.; Unger, Jennifer B.; Chou, Chih-Ping; Spruijt-Metz, Donna; Pentz, Mary Ann; Riggs, Nathaniel R.

2015-01-01

Objective: This study tested the relationships among child executive function (EF), child-perceived parent fast food intake, and child self-reported subsequent consumption of high-calorie, low-nutrient (HCLN) food. Design: One year and 6-month longitudinal observation from a larger randomized controlled trial. Setting. Southern California…

Transmission characteristics of Bessel-Gaussian vortex beams propagating along both longitudinal and transverse directions in a subway tunnel

NASA Astrophysics Data System (ADS)

Wang, Xiaohui; Song, Yingxiong

2018-02-01

By exploiting the non-Kolmogorov model and Rytov approximation theory, a propagation model of Bessel-Gaussian vortex beams (BGVB) propagating in a subway tunnel is derived. Based on the propagation model, a model of orbital angular momentum (OAM) mode probability distribution is established to evaluate the propagation performance when the beam propagates along both longitudinal and transverse directions in the subway tunnel. By numerical simulations and experimental verifications, the influences of the various parameters of BGVB and turbulence on the OAM mode probability distribution are evaluated, and the results of simulations are consistent with the experimental statistics. The results verify that the middle area of turbulence is more beneficial for the vortex beam propagation than the edge; when the BGVB propagates along the longitudinal direction in the subway tunnel, the effects of turbulence on the OAM mode probability distribution can be decreased by selecting a larger anisotropy parameter, smaller coherence length, larger non-Kolmogorov power spectrum coefficient, smaller topological charge number, deeper subway tunnel, lower train speed, and longer wavelength. When the BGVB propagates along the transverse direction, the influences can be also mitigated by adopting a larger topological charge number, less non-Kolmogorov power spectrum coefficient, smaller refractive structure index, shorter wavelength, and shorter propagation distance.

Bidirectional influence: A longitudinal analysis of size of drug network and depression among inner-city residents in Baltimore, Maryland

PubMed Central

Yang, Jingyan; Latkin, Carl A.; Davey-Rothwell, Melissa

2015-01-01

BACKGROUND The prevalence of depression among drug users is high. It has been recognized that drug use behaviors can be influenced and spread through social networks. OBJECTIVES We investigated the directional relationship between social network factors and depressive symptoms among a sample of inner-city residents in Baltimore, MD. METHODS We performed a longitudinal study of four-wave data collected from a network-based HIV/STI prevention intervention for women and network members, consisting of both men and women. Our primary outcome and exposure were depression using CESD scale and social network characteristics, respectively. Linear mixed model with clustering adjustment was used to account for both repeated measurement and network design. RESULTS Of the 746 participants, those who had high levels of depression tended to be female, less educated, homeless, smokers, and did not have a main partner. In the univariate longitudinal model, larger size of drug network was significantly associated with depression (OR=1.38, p<0.001). This relationship held after controlling for age, gender, homeless in the past six months, college education, having a main partner, cigarette smoking, perceived health, and social support network (aOR=1.19, p=0.001). In the univariate mixed model using depression to predict size of drug network, the data suggested that depression was associated with larger size of drug network (coef.=1.23, p<0.001) and the same relation held in multivariate model (adjusted coef.=1.08, p=0.001). CONCLUSIONS The results suggest that larger size of drug network is a risk factor for depression, and vice versa. Further intervention strategies to reduce depression should address social networks factors. PMID:26584046

A longitudinal study of trunk muscle properties and severity of thoracic kyphosis in women and men: The Framingham Study.

PubMed

Lorbergs, Amanda L; Allaire, Brett T; Yang, Laiji; Kiel, Douglas P; Cupples, L Adrienne; Jarraya, Mohamed; Guermazi, Ali; Travison, Thomas G; Bouxsein, Mary L; Anderson, Dennis E; Samelson, Elizabeth J

2018-04-24

Cross-sectional studies suggest that trunk muscle morphology in the lumbar spine is an important determinant of kyphosis severity in older adults. The contribution of age-related changes in muscle morphology in the thoracic and lumbar spine to progression of kyphosis is not known. Our objective was to determine cross-sectional and longitudinal associations of thoracic and lumbar muscle size and density with kyphosis. Participants were 1,087 women and men (mean age 61y) of the Framingham Heart Study who underwent baseline and follow-up quantitative computed tomography (QCT) scanning 6y apart. We used QCT scans to measure trunk muscle cross-sectional area (CSA, cm2) and density (HU) at the thoracic and lumbar spine and Cobb angle (degrees) from T4 to T12. Linear regression models estimated the association between muscle morphology and kyphosis. At baseline, smaller muscle CSA and lower density of thoracic (but not lumbar) spine muscles were associated with a larger (worse) Cobb angle in women and men. For example, each standard deviation (SD) decrease in baseline thoracic paraspinal muscle CSA was associated with a larger baseline Cobb angle in women (3.7°, 95%CI:2.9, 4.5) and men (2.5°, 95%CI:1.6, 3.3). Longitudinal analyses showed that loss of muscle CSA and density at the thoracic and lumbar spine was not associated with progression of kyphosis. Our findings suggest that kyphosis severity is related to smaller and lower density trunk muscles at the thoracic spine. Future studies are needed to determine how strengthening mid-back musculature alters muscle properties and contributes to preventing kyphosis progression.

Do stressed mothers have heavier children?: A meta-analysis on the relationship between maternal stress and child body mass index

PubMed Central

Tate, Eleanor B.; Wood, Wendy; Liao, Yue; Dunton, Genevieve F.

2015-01-01

Child obesity continues to be a prevalent public health issue. This meta-analysis synthesized 17 studies investigating the association between levels of psychological stress experienced by mothers and the body mass index of their children. The overall standardized mean difference effect size was positive and significantly different from zero in cross-sectional d = 0.20 [k = 14, 95% Confidence Interval (CI): 0.06, 0.34] and longitudinal studies d = 0.18 (k = 5, 95% CI: 0.00, 0.351), and had significant heterogeneity in both [cross-sectional, Q(13) = 193.00, p < 0.001; longitudinal, Q(4) = 29.46, p < 0.001]. In longitudinal studies, effect sizes were larger when children also would have experienced the stressor, Q(6) = 4.68, p < 0.05, for toddlers than infants, Q(4) = 5.04, p < 0.05, and in higher quality studies, Q(4) = 14.58, p < 0.05. Results highlight the potential benefits of including a parent stress management component in childhood obesity prevention programs. PMID:25879393

Experimental study on burning rates of square/rectangular gasoline and methanol pool fires under longitudinal air flow in a wind tunnel.

PubMed

Hu, L H; Liu, S; Peng, W; Huo, R

2009-09-30

Square pool fires with length of 5, 7.5, 10, 15, 20, 25 and 30 cm and rectangular pool fires with dimensions of 10 cm x 20 cm and 10 cm x 40 cm were burned in a wind tunnel, under a longitudinal air flow ranged from 0 to 3m/s with incremental change of about 0.5m/s. Methanol and gasoline were burned and compared, with results indicated that their burning rates showed different response to the longitudinal air flow. With the increase of the longitudinal air flow speed, the burning rates of methanol pool fires, except the 5 cm square one, first decreased and then increased, but those of the 5 cm methanol square one and the gasoline pool fires increased monotonously. The burning rate of smaller square pool fires increased more significantly than that of the larger ones, as well as the enlargement of their flame attachment length along the ground. The burning rate of a rectangular pool fire with longer rim parallel to the longitudinal flow increased faster, but the flame attachment length seemed to increase more gradually, with the increase of the longitudinal air flow speed than that perpendicular to.

How Black Boys with Disabilities End up in Honors Classes while Others without Disabilities End up in Special Education

ERIC Educational Resources Information Center

Toldson, Ivory A.

2011-01-01

For the data presented in this report, the author analyzed 17,587 Black, Hispanic, and White male and female students (Black males; N = 1,149) who completed the High School Longitudinal Study of 2009 (Ingels et al., 2011). This is a brief report from a larger study completed under the auspices of the National Dropout Prevention Center for Students…

FE Analysis of Buckling Behavior Caused by Welding in Thin Plates of High Tensile Strength Steel

NASA Astrophysics Data System (ADS)

Wang, Jiangchao; Rashed, Sherif; Murakawa, Hidekazu

2014-12-01

The target of this study was to investigate buckling behavior during the entire welding process which consists of the heating and the cooling processes. For thin plate structures made of high tensile strength steel, not only residual buckling during or after cooling down but also transient buckling during heating may occur. The thermal elastic plastic FE analysis to investigate welding-induced buckling during the entire welding process is presented. Because of the high yield stress of high tensile strength steel, larger longitudinal compressive thermal stress is produced near the welding line compared with that in the case of carbon steel. Therefore, the plate may buckle due to thermal expansion, before the material nears yielding. During cooling down, the longitudinal compressive thermal stress close to the welding line disappears, and longitudinal tensile residual stress is produced due to contraction. Meanwhile, longitudinal compressive residual stress occurs far from the welding line to balance the tensile stress close to the welding line. This distribution of longitudinal residual stress would change the deformed dish shape of transient buckling into a saddle buckling type when the stress exceeds the critical buckling condition.

Measurement and simulation of the RHIC abort kicker longitudinal impedence

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

Abreu,N.P.; Hahn,H.; Choi, E.

2009-09-01

In face of the new upgrades for RHIC the longitudinal impedance of the machine plays an important role in setting the threshold for instabilities and the efficacy of some systems. In this paper we describe the measurement of the longitudinal impedance of the abort kicker for RHIC as well as computer simulations of the structure. The impedance measurement was done by the S{sub 21} wire method covering the frequency range from 9 kHz to 2.5 GHz. We observed a sharp resonance peak around 10 MHz and a broader peak around 20 MHz in both, the real and imaginary part, ofmore » the Z/n. These two peaks account for a maximum imaginary longitudinal impedance of j15 {Omega}, a value an order of magnitude larger than the estimated value of j0.2 {Omega}, which indicates that the kicker is one of the main sources of longitudinal impedance in the machine. A computer model was constructed for simulations in the CST MWS program. Results for the magnet input and the also the beam impedance are compared to the measurements. A more detail study of the system properties and possible changes to reduce the coupling impedance are presented.« less

Teaching Students and Teaching Each Other: The Importance of Peer Learning for Teachers. NBER Working Paper No. 15202

ERIC Educational Resources Information Center

Jackson, C. Kirabo; Bruegmann, Elias

2009-01-01

Using longitudinal elementary school teacher and student data, we document that students have larger test score gains when their teachers experience improvements in the observable characteristics of their colleagues. Using within-school and within-teacher variation, we further show that a teacher's students have larger achievement gains in math…

Nonlinear longitudinal resonance interaction of energetic charged particles and VLF waves in the magnetosphere

NASA Technical Reports Server (NTRS)

Tkalcevic, S.

1982-01-01

The longitudinal resonance of waves and energetic electrons in the Earth's magnetosphere, and the possible role this resonance may play in generating various magnetospheric phenomena are studied. The derivation of time-averaged nonlinear equations of motion for energetic particles longitudinally resonant with a whistler mode wave propagating with nonzero wave normal is considered. It is shown that the wave magnetic forces can be neglected at lower particle pitch angles, while they become equal to or larger than the wave electric forces for alpha 20 deg. The time-averaged equations of motion were used in test particle simulation which were done for a wide range of wave amplitudes, wave normals, particle pitch angles, particle parallel velocities, and in an inhomogeneous medium such as the magnetosphere. It was found that there are two classes of particles, trapped and untrapped, and that the scattering and energy exchange for those two groups exhibit significantly different behavior.

Movie Smoking Exposure and Smoking Onset: A Longitudinal Study of Mediation Processes in a Representative Sample of U.S. Adolescents

PubMed Central

Wills, Thomas A.; Sargent, James D.; Stoolmiller, Mike; Gibbons, Frederick X.; Gerrard, Meg

2009-01-01

The authors tested 2 mechanisms for the relation of movie smoking exposure with onset of cigarette smoking in adolescence. Longitudinal data with 8-month follow-up were obtained from a representative sample of 6,522 U.S. adolescents, ages 10–14 years. Structural modeling analysis based on initial nonsmokers, which controlled for 10 covariates associated with movie exposure, showed that viewing more smoking in movies was related to increases in positive expectancies about smoking and increases in affiliation with smoking peers, and these variables were both related to smoking onset. A direct effect of movie exposure on smoking onset was also noted. Mediation findings were replicated across cross-sectional and longitudinal analyses. Tests for gender differences indicated that girls showed larger effects of movie exposure for some variables. Implications for policy and prevention research are discussed. PMID:18540724

Verbal Memory Declines More Rapidly with Age in HIV Infected versus Uninfected Adults

PubMed Central

Seider, Talia R.; Luo, Xi; Gongvatana, Assawin; Devlin, Kathryn N.; de la Monte, Suzanne M.; Chasman, Jesse D.; Yan, Peisi; Tashima, Karen T.; Navia, Bradford; Cohen, Ronald A.

2015-01-01

Objectives In the current era of effective antiretroviral treatment, the number of older adults living with HIV is rapidly increasing. This study investigated the combined influence of age and HIV infection on longitudinal changes in verbal and visuospatial learning and memory. Methods In this longitudinal, case-control design, 54 HIV seropositive and 30 seronegative individuals aged 40–74 received neurocognitive assessments at baseline visits and again one year later. Assessment included tests of verbal and visuospatial learning and memory. Linear regression was used to predict baseline performance and longitudinal change on each test using HIV serostatus, age, and their interaction as predictors. MANOVA was used to assess the effects of these predictors on overall baseline performance and overall longitudinal change. Results The interaction of HIV and age significantly predicted longitudinal change in verbal memory performance, as did HIV status, indicating that although the seropositive group declined more than the seronegative group overall, the rate of decline depended on age such that greater age was associated with a greater decline in this group. The regression models for visuospatial learning and memory were significant at baseline, but did not predict change over time. HIV status significantly predicted overall baseline performance and overall longitudinal change. Conclusions This is the first longitudinal study focused on the effects of age and HIV on memory. Findings suggest that age and HIV interact to produce larger declines in verbal memory over time. Further research is needed to gain a greater understanding of the effects of HIV on the aging brain. PMID:24645772

Longitudinal patterns of employment and postsecondary education for adults with autism and average-range IQ.

PubMed

Taylor, Julie Lounds; Henninger, Natalie A; Mailick, Marsha R

2015-10-01

This study examined correlates of participation in postsecondary education and employment over 12 years for 73 adults with autism spectrum disorders and average-range IQ whose families were part of a larger, longitudinal study. Correlates included demographic (sex, maternal education, paternal education), behavioral (activities of daily living, maladaptive behaviors, autism symptoms), and family (size of maternal social network; maternal depressive symptoms, anxiety, and pessimism) factors. Although two-thirds of adults with autism spectrum disorder participated in competitive employment/postsecondary education during the study, fewer than 25% maintained these activities over the study period. Behavioral characteristics distinguished those who never had competitive employment/postsecondary education from those who sometimes or consistently participated in these activities. Women were considerably less likely than men to maintain employment/postsecondary education over time. © The Author(s) 2015.

The Persistence of Preschool Effects: A Long-Term Follow-Up of Fourteen Infant and Preschool Experiences. Summary Report.

ERIC Educational Resources Information Center

Lazar, Irving; And Others

This paper summarizes a larger report of the findings of the Developmental Continuity Consortium, a collaborative effort of twelve research groups conducting longitudinal studies on the outcomes of early education programs for low-income children initiated in the 1960's. Summarized are: (1) Methods (problems of secondary analysis, problems of…

Intersubjective Interaction between Deaf Parents/Deaf Infants during the Infant's First 18 Months

ERIC Educational Resources Information Center

Roos, Carin; Cramér-Wolrath, Emelie; Falkman, Kerstin W.

2016-01-01

This study is part of a larger longitudinal project with the aim of focusing early social interaction and development of mentalizing ability in 12 deaf infants, including the interaction between the infants and their deaf parents. The aim of the present paper is to describe early social interaction and moments of intersubjectivity between the deaf…

Relations of Children's Effortful Control and Teacher-Child Relationship Quality to School Attitudes in a Low-Income Sample

ERIC Educational Resources Information Center

Silva, Kassondra M.; Spinrad, Tracy L.; Eisenberg, Nancy; Sulik, Michael J.; Valiente, Carlos; Huerta, Snjezana; Edwards, Alison; Eggum, Natalie D.; Kupfer, Anne S.; Lonigan, Christopher J.; Phillips, Beth M.; Wilson, Shauna B.; Clancy-Menchetti, Jeanine; Landry, Susan H.; Swank, Paul R.; Assel, Michael A.; Taylor, Heather B.

2011-01-01

Research Findings: The purpose of this study was to examine the relations of children's effortful control and quality of relationships with teachers to school attitudes longitudinally in an ethnically diverse and economically disadvantaged sample. Data were collected as part of a larger intervention project during mid-fall, winter, and late spring…

Self-Regulation in Early Adolescence: Relations with Mother-Son Relationship Quality and Maternal Regulatory Support and Antagonism

ERIC Educational Resources Information Center

Moilanen, Kristin L.; Shaw, Daniel S.; Fitzpatrick, Amber

2010-01-01

The purpose of the current investigation was to examine relations among maternal regulatory support, maternal antagonism, and mother-son relationship quality in relation to boys' self-regulation during early adolescence. As part of a larger longitudinal study on 263 low-income, ethnically diverse boys, multiple informants and methods were used to…

The Impact of Junior High School and Puberty upon Self-Esteem.

ERIC Educational Resources Information Center

Simmons, Roberta G.; And Others

This longitudinal study measured the impact of pubertal development, sex, race, and school type on the self-esteem of 12- and 13-year-old children. One of the questions being investigated was whether the move from a protected elementary school into a larger, more impersonal junior high affected children's self-image more negatively than did a move…

Longitudinal association of hemostatic factors with risk for cancers of the breast, colorectum, and lung among postmenopausal women.

PubMed

Kabat, Geoffrey C; Salazar, Christian R; Zaslavsky, Oleg; Lane, Dorothy S; Rohan, Thomas E

2016-09-01

The aim of this study was to examine whether hemostatic factors associated with coagulation and inflammation pathways are associated with cancer risk in postmenopausal women. We used data from the Women's Health Initiative study to examine the association of plasma fibrinogen levels, factor VII antigen activity, and factor VII concentration measured at baseline and during follow-up with the risk for cancers of the breast, colorectum, and lung. Among 5287 women who were followed up for a median of 11.4 years, 275 cases of breast cancer, 102 cases of colorectal cancer, and 90 cases of lung cancer were identified. Cox proportional hazards models were used to estimate hazard ratios and 95% confidence intervals for the association of hemostatic factors with each cancer. Hemostatic factors were not associated with breast cancer in either baseline or longitudinal analyses. Baseline hemostatic factors showed weak associations with colorectal cancer; however, no association was seen in longitudinal analyses. Fibrinogen was positively associated with lung cancer in both baseline and longitudinal analyses; the association was seen only in never and former smokers, not in current smokers. We found no evidence of an association between hemostatic factors and breast or colorectal cancer in postmenopausal women. The positive association of fibrinogen levels with lung cancer requires confirmation in larger studies.

Study of working principle and thermal balance process of a double longitudinal-mode He-Ne laser

NASA Astrophysics Data System (ADS)

Wang, Li-qiang

2009-07-01

A double longitudinal mode He-Ne laser with frequency stabilization is proposed. Compared with general methods, such as Lamb dip, Zeeman splitting and molecule saturation absorption method, this design has some advantages, such as no piezocrystal or magnetic field, a short frequency-stabilized time, lower cost, and higher frequency stability and reproducibility. The metal wire is uniformly wrapped on the discharge tube of the laser. When the metal wire is heated up, the resonant cavity changes with the temperature field around the discharge tube to make the frequency of the laser to be tuned. The polarizations of the two longitudinal modes from the laser must be orthogonal. The parallelly polarized light and the vertically polarized light compete with each other, i. e., the parallelly polarized light generates a larger output power, while, the vertically polarized light correspondingly generates a smaller one, but an equal value is found at the reference frequencies by automatically adjusting the length of the resonant cavity, due to change of the temperature in the discharge tube. Consequently the frequencies of the laser are stabilized. In my experiment, an intracavity He-Ne laser whose length of the resonant cavity is larger than 50mm and smaller than 300mm is selected for the double longitudinal-mode laser. Influence factors of frequency stability of this laser is only change of the length of the resonant cavity. The laser includes three stages: mode hopping, transition stage, and modes stability from startup to laser stability. When this laser is in modes stability, the waveform of heating metal wire is observed to a pulse whose duty is almost 50%, and thermal balances of the resonant cavity mainly rely on discharge tube.

Longitude-dependent lunar tidal modulation of the equatorial electrojet during stratospheric sudden warmings

NASA Astrophysics Data System (ADS)

Siddiqui, Tarique A.; Stolle, Claudia; Lühr, Hermann

2017-03-01

The effects of coupling between different layers of the atmosphere during Stratospheric Sudden Warming (SSW) events have been studied quite extensively in the past few years, and in this context large lunitidal enhancements in the equatorial ionosphere have also been widely discussed. In this study we report about the longitudinal variabilities in lunitidal enhancement in the equatorial electrojet (EEJ) during SSWs through ground and space observations in the Peruvian and Indian sectors. We observe that the amplification of lunitidal oscillations in EEJ is significantly larger over the Peruvian sector in comparison to the Indian sector. We further compare the lunitidal oscillations in both the sectors during the 2005-2006 and 2008-2009 major SSW events and during a non-SSW winter of 2006-2007. It is found that the lunitidal amplitude in EEJ over the Peruvian sector showed similar enhancements during both the major SSWs, but the enhancements were notably different in the Indian sector. Independent from SSW events, we have also performed a climatological analysis of the lunar modulation of the EEJ during December solstice over both the sectors by using 10 years of CHAMP magnetic measurements and found larger lunitidal amplitudes over the Peruvian sector confirming the results from ground magnetometer observations. We have also analyzed the semidiurnal lunar tidal amplitude in neutral temperature measurements from Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) at 110 km and found lesser longitudinal variability than the lunitidal amplitude in EEJ. Our results suggest that the longitudinal variabilities in lunitidal modulation of the EEJ during SSWs could be related to electrodynamics in the E region dynamo.

The Impact of External Employment on 12th Grade Student Participation in Extracurricular Activities as a Function of School Size

ERIC Educational Resources Information Center

Garcia, Miguel A.

2012-01-01

Data from the Educational Longitudinal Study of 2002 were used to compare 11,000 high school students on school size, time spent participating in extracurricular activities (ECA), and hours spent in employment. Findings indicated that students from small schools spent more time participating in ECA than students from larger schools for equivalent…

Brief Report: Executive Function as a Predictor of Academic Achievement in School-Aged Children with ASD

ERIC Educational Resources Information Center

St. John, Tanya; Dawson, Geraldine; Estes, Annette

2018-01-01

The contributions of Executive Function (EF) to academic achievement in children with Autism Spectrum Disorder (ASD) are not well understood. Academic achievement and its association with EF is described in 32, 9-year-old children with ASD. EF at age 6 and 9, and academic achievement at age 9 were assessed as part of a larger longitudinal study.…

Psychosocial predictors of somatic symptoms in adolescents of parents with HIV: a six-year longitudinal study.

PubMed

Bursch, B; Lester, P; Jiang, L; Rotheram-Borus, M J; Weiss, R

2008-07-01

The objective of this study was to identify salient parent and adolescent psychosocial factors related to somatic symptoms in adolescents. As part of a larger intervention study conducted in New York, 409 adolescents were recruited from 269 parents with HIV. A longitudinal model predicted adolescent somatization scores six years after baseline assessment. Adolescent somatic symptoms were assessed at baseline and at 3-month intervals for the first two years and then at 6-month intervals using the Brief Symptom Inventory. Baseline data from adolescents and parents were used to predict adolescent somatic symptoms. Variables related to increased adolescent somatic symptoms over six years included being younger and female; an increased number of adolescent medical hospitalizations; more stressful life events; adolescent perception of a highly rejecting parenting style; more parent-youth conflict; no experience of parental death; and parental distress over their own pain symptoms. Our findings extend the literature by virtue of the longitudinal design; inclusion of both parent and child variables in one statistical model; identification of study participants by their potentially stressful living condition rather than by disease or somatic symptom status; and inclusion of serious parental illness and death in the study.

Longitudinal association between eating frequency and HbA1c and serum lipids in diabetes in the SEARCH for Diabetes in Youth Study.

PubMed

Li, Chao; D'Agostino, Ralph B; Dabelea, Dana; Liese, Angela D; Mayer-Davis, Elizabeth J; Pate, Russell; Merchant, Anwar T

2018-04-30

Few studies have evaluated the prospective association of eating frequency with HbA1c levels and cardiovascular disease risk markers among youth with diabetes. To examine the 5-year longitudinal association of eating frequency with HbA1c and serum lipid levels among youth with type 1 diabetes (T1D) or type 2 diabetes (T2D). 1,049 youth (≥10 years old) with incident T1D (n=821) or T2D (n=228) who participated in the SEARCH for Diabetes in Youth Study were included. Eating frequency (≤3, 4-5 or 6-10 times/day) measured at baseline and follow-up visits was related to HbA1c and serum lipid levels measured repeatedly over 5 years. Increased eating frequency was associated with larger increases in HbA1c among youth T1D. For example, for youth with T1D who ate ≤ 3 times/day at the outset and ate 6-10 times/day 5 years later, the longitudinal model predicted greater absolute increases in HbA1c (2.77%); whereas for youth with T1D who ate 6-10 times/day at the outset and ate ≤3 times/day 5 years later, the model predicted lesser absolute increases in HbA1c (1.33%). Eating frequency was not associated with changes in serum lipid levels among youth with T1D or T2D. Youth with T1D who increased their eating frequency vs. those who decreased it had larger increases in HbA1c over 5 years. This article is protected by copyright. All rights reserved.

Evolution of deep gray matter volume across the human lifespan.

PubMed

Narvacan, Karl; Treit, Sarah; Camicioli, Richard; Martin, Wayne; Beaulieu, Christian

2017-08-01

Magnetic resonance imaging of subcortical gray matter structures, which mediate behavior, cognition and the pathophysiology of several diseases, is crucial for establishing typical maturation patterns across the human lifespan. This single site study examines T1-weighted MPRAGE images of 3 healthy cohorts: (i) a cross-sectional cohort of 406 subjects aged 5-83 years; (ii) a longitudinal neurodevelopment cohort of 84 subjects scanned twice approximately 4 years apart, aged 5-27 years at first scan; and (iii) a longitudinal aging cohort of 55 subjects scanned twice approximately 3 years apart, aged 46-83 years at first scan. First scans from longitudinal subjects were included in the cross-sectional analysis. Age-dependent changes in thalamus, caudate, putamen, globus pallidus, nucleus accumbens, hippocampus, and amygdala volumes were tested with Poisson, quadratic, and linear models in the cross-sectional cohort, and quadratic and linear models in the longitudinal cohorts. Most deep gray matter structures best fit to Poisson regressions in the cross-sectional cohort and quadratic curves in the young longitudinal cohort, whereas the volume of all structures except the caudate and globus pallidus decreased linearly in the longitudinal aging cohort. Males had larger volumes than females for all subcortical structures, but sex differences in trajectories of change with age were not significant. Within subject analysis showed that 65%-80% of 13-17 year olds underwent a longitudinal decrease in volume between scans (∼4 years apart) for the putamen, globus pallidus, and hippocampus, suggesting unique developmental processes during adolescence. This lifespan study of healthy participants will form a basis for comparison to neurological and psychiatric disorders. Hum Brain Mapp 38:3771-3790, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Longitudinal and Circumferential Strain of the Proximal Aorta

PubMed Central

Bell, Vanessa; Mitchell, William A.; Sigurðsson, Sigurður; Westenberg, Jos J. M.; Gotal, John D.; Torjesen, Alyssa A.; Aspelund, Thor; Launer, Lenore J.; de Roos, Albert; Gudnason, Vilmundur; Harris, Tamara B.; Mitchell, Gary F.

2014-01-01

Background Accurate assessment of mechanical properties of the proximal aorta is a requisite first step for elucidating the pathophysiology of isolated systolic hypertension. During systole, substantial proximal aortic axial displacement produces longitudinal strain, which we hypothesize causes variable underestimation of ascending aortic circumferential strain compared to values in the longitudinally constrained descending aorta. Methods and Results To assess effects of longitudinal strain, we performed magnetic resonance imaging in 375 participants (72 to 94 years old, 204 women) in the Age, Gene/Environment Susceptibility‐Reykjavik Study and measured aortic circumferential and longitudinal strain. Circumferential ascending aortic area strain uncorrected for longitudinal strain was comparable in women and men (mean [95% CI], 8.3 [7.8, 8.9] versus 7.9 [7.4, 8.5]%, respectively, P=0.3). However, longitudinal strain was greater in women (8.5±2.5 versus 7.0±2.5%, P<0.001), resulting in greater longitudinally corrected circumferential ascending aortic strain (14.4 [13.6, 15.2] versus 13.0 [12.4, 13.7]%, P=0.010). Observed circumferential descending aortic strain, which did not require correction (women: 14.0 [13.2, 14.8], men: 12.4 [11.6, 13.2]%, P=0.005), was larger than uncorrected (P<0.001), but comparable to longitudinally corrected (P=0.12) circumferential ascending aortic strain. Carotid‐femoral pulse wave velocity did not correlate with uncorrected ascending aortic strain (R=−0.04, P=0.5), but was inversely related to longitudinally corrected ascending and observed descending aortic strain (R=−0.15, P=0.004; R=−0.36, P<0.001, respectively). Longitudinal strain was also inversely related to carotid‐femoral pulse wave velocity and other risk factors for higher aortic stiffness including treated hypertension. Conclusions Longitudinal strain creates substantial and variable errors in circumferential ascending aortic area strain measurements, particularly in women, and should be considered to avoid misclassification of ascending aortic stiffness. PMID:25523153

Investigation of longitudinal control system for a small hydrofoil boat

NASA Technical Reports Server (NTRS)

Phillips, W. H.; Shaughnessy, J. D.

1976-01-01

An analysis of a hydromechanical system for longitudinal control of a small hydrofoil boat is presented. The system incorporates height and acceleration sensors operating flaps on the foils through a mechanical linkage. Effects of some of the system parameters on the stability and response to waves are shown. The results indicate that the system is capable of providing adequate stability, but the response to stern waves at low frequencies is larger than desired.

Do stressed mothers have heavier children? A meta-analysis on the relationship between maternal stress and child body mass index.

PubMed

Tate, E B; Wood, W; Liao, Y; Dunton, G F

2015-05-01

Child obesity continues to be a prevalent public health issue. This meta-analysis synthesized 17 studies investigating the association between levels of psychological stress experienced by mothers and the body mass index of their children. The overall standardized mean difference effect size was positive and significantly different from zero in cross-sectional d = 0.20 (k = 14, 95% confidence interval [CI]: 0.06, 0.34) and longitudinal studies d = 0.18 (k = 5, 95% CI: 0.00, 0.351) and had significant heterogeneity in both (cross-sectional, Q[13] = 193.00, P < 0.001; longitudinal, Q[4] = 29.46, P < 0.001). In longitudinal studies, effect sizes were larger when children also would have experienced the stressor, Q(6) = 4.68, P < 0.05, for toddlers than infants, Q(4) = 5.04, P < 0.05, and in higher quality studies, Q(4) = 14.58, P < 0.05. Results highlight the potential benefits of including a parent stress management component in childhood obesity prevention programmes. © 2015 World Obesity.

Longitudinal decline in pulmonary diffusing capacity among nitrate fertilizer workers.

PubMed

Hovland, K H; Skogstad, M; Bakke, B; Skare, Ø; Skyberg, K

2014-04-01

This study is part of a 3-year follow-up of lung function among nitrate fertilizer production workers. To study the possible adverse effects of occupational exposure to aerosols and gases on pulmonary diffusing capacity. A longitudinal study of a cohort of fertilizer workers who performed single-breath carbon monoxide diffusing capacity (DLco) tests and spirometry in 2007 and 2010. The workers completed a questionnaire on respiratory symptoms and smoking habits. Exposure to mineral dust, acid aerosols and inorganic gases was measured. The overall median inhalable and thoracic aerosol mass concentrations were 1.1mg/m(3) (min-max: <0.93-45) and 0.21mg/m(3) (min-max: <0.085-11), respectively. There were 308 participants in 2007 with 168 returning subjects in 2010. Overall, we found a statistically significant decline in the DLco of 0.068 mmol/min/kPa/year, adjusted for gender, age, height, weight, smoking status and doctor-diagnosed asthma during the 3-year follow-up (P < 0.01). The change in DLco did not vary significantly between the various job groups. Subjects with respiratory symptoms did not show a larger decline in DLco than those without symptoms. This study indicates a larger than expected decline in the DLco of fertilizer workers during a 3-year follow-up. However, the decline was not related to specific exposures at work, or to possible covariates of exposure.

Spirituality: a cultural strength for African American mothers with HIV.

PubMed

Polzer Casarez, Rebecca L; Miles, Margaret Shandor

2008-05-01

The purpose of this study was to describe how spirituality affected the lives of African American mothers with Human Immunodeficiency Virus (HIV) in the context of coping. This qualitative descriptive study used secondary data of interviews from a larger longitudinal study of parental caregiving of infants seropositive for HIV. Participants were 38 African American mothers with HIV. Data from longitudinal semi-structured interviews were analyzed using content analysis. The women dealt with the stresses of HIV through a relationship with God. Two domains explain this relationship: God in control and God requires participation. The benefits of their relationship with God were a decrease in stress and worry about their own health and that of their infants. It is important for nurses working with mothers with HIV to acknowledge their spirituality and assess how spirituality helps them cope with and manage their illness.

An exploratory longitudinal study of social and language outcomes in children with autism in bilingual home environments.

PubMed

Zhou, Vanessa; Munson, Jeffrey A; Greenson, Jessica; Hou, Yan; Rogers, Sally; Estes, Annette M

2017-12-01

Little is known about outcomes of early intervention for children with autism spectrum disorder reared in bilingual homes. There are concerns that social communication deficits among children with autism spectrum disorder may reduce the developmental benefits of early intervention for children with autism spectrum disorder raised in bilingual environments. We conducted an exploratory analysis of cross-sectional and longitudinal data from a larger study to explore associations between home language environment and language ability and social skills in response to early autism spectrum disorder intervention. Participants, aged 12-26 months when recruited, were a subset of a larger 2-year, randomized intervention trial (ClinicalTrials.gov identifier: NCT00698997). Children from bilingual homes ( n = 13) began intervention with lower gesture use but otherwise demonstrated equal baseline language and social abilities as compared with age and nonverbal IQ-matched children from monolingual homes ( n = 24). Significant language growth was exhibited by children from both language groups and there was no moderating effect of home language environment. The bilingual home group demonstrated increased gesture use over the course of intervention as compared with the monolingual home group. Preliminary data revealed no basis for concerns regarding negative impact of a bilingual home environment on language or social development in young children with autism spectrum disorder.

Quantifying the individual-level association between income and mortality risk in the United States using the National Longitudinal Mortality Study.

PubMed

Brodish, Paul Henry; Hakes, Jahn K

2016-12-01

Policy makers would benefit from being able to estimate the likely impact of potential interventions to reverse the effects of rapidly rising income inequality on mortality rates. Using multiple cohorts of the National Longitudinal Mortality Study (NLMS), we estimate the absolute income effect on premature mortality in the United States. A multivariate Poisson regression using the natural logarithm of equivilized household income establishes the magnitude of the absolute income effect on mortality. We calculate mortality rates for each income decile of the study sample and mortality rate ratios relative to the decile containing mean income. We then apply the estimated income effect to two kinds of hypothetical interventions that would redistribute income. The first lifts everyone with an equivalized household income at or below the U.S. poverty line (in 2000$) out of poverty, to the income category just above the poverty line. The second shifts each family's equivalized income by, in turn, 10%, 20%, 30%, or 40% toward the mean household income, equivalent to reducing the Gini coefficient by the same percentage in each scenario. We also assess mortality disparities of the hypothetical interventions using ratios of mortality rates of the ninth and second income deciles, and test sensitivity to the assumption of causality of income on mortality by halving the mortality effect per unit of equivalized household income. The estimated absolute income effect would produce a three to four percent reduction in mortality for a 10% reduction in the Gini coefficient. Larger mortality reductions result from larger reductions in the Gini, but with diminishing returns. Inequalities in estimated mortality rates are reduced by a larger percentage than overall estimated mortality rates under the same hypothetical redistributions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Exploring the Social Integration of Sexual Minority Youth Across High School Contexts

PubMed Central

Martin-Storey, Alexa; Cheadle, Jacob E.; Skalamera, Julie; Crosnoe, Robert

2014-01-01

Mental health disparities between sexual minority and other youth have been theorized to result in part from the effects of the stigmatization on social integration. Stochastic actor-based modeling was applied to complete network data from two high schools in the National Longitudinal Study of Adolescent Health (mean age =15 years, n=2,533). Same-sex attracted youth were socially marginalized in a smaller predominantly White school but not in a larger, more racially diverse school. For both schools, homophily was a critical network feature, and could represent social support for and social segregation of such youth. These findings emphasize school context in studying the social lives of sexual minority youth and suggest that youth may be better off socially in larger and more diverse schools. PMID:25689110

Examining the Variability of Sleep Patterns during Treatment for Chronic Insomnia: Application of a Location-Scale Mixed Model.

PubMed

Ong, Jason C; Hedeker, Donald; Wyatt, James K; Manber, Rachel

2016-06-15

The purpose of this study was to introduce a novel statistical technique called the location-scale mixed model that can be used to analyze the mean level and intra-individual variability (IIV) using longitudinal sleep data. We applied the location-scale mixed model to examine changes from baseline in sleep efficiency on data collected from 54 participants with chronic insomnia who were randomized to an 8-week Mindfulness-Based Stress Reduction (MBSR; n = 19), an 8-week Mindfulness-Based Therapy for Insomnia (MBTI; n = 19), or an 8-week self-monitoring control (SM; n = 16). Sleep efficiency was derived from daily sleep diaries collected at baseline (days 1-7), early treatment (days 8-21), late treatment (days 22-63), and post week (days 64-70). The behavioral components (sleep restriction, stimulus control) were delivered during late treatment in MBTI. For MBSR and MBTI, the pre-to-post change in mean levels of sleep efficiency were significantly larger than the change in mean levels for the SM control, but the change in IIV was not significantly different. During early and late treatment, MBSR showed a larger increase in mean levels of sleep efficiency and a larger decrease in IIV relative to the SM control. At late treatment, MBTI had a larger increase in the mean level of sleep efficiency compared to SM, but the IIV was not significantly different. The location-scale mixed model provides a two-dimensional analysis on the mean and IIV using longitudinal sleep diary data with the potential to reveal insights into treatment mechanisms and outcomes. © 2016 American Academy of Sleep Medicine.

Experimental investigation of clogging dynamics in homogeneous porous medium

NASA Astrophysics Data System (ADS)

Shen, Jikang; Ni, Rui

2017-03-01

A 3-D refractive-index matching Lagrangian particle tracking (3D-RIM-LPT) system was developed to study the filtration and the clogging process inside a homogeneous porous medium. A small subset of particles flowing through the porous medium was dyed and tracked. As this subset was randomly chosen, its dynamics is representative of all the rest. The statistics of particle locations, number, and velocity were obtained as functions of different volumetric concentrations. It is found that in our system the clogging time decays with the particle concentration following a power law relationship. As the concentration increases, there is a transition from depth filtration to cake filtration. At high concentration, more clogged pores lead to frequent flow redirections and more transverse migrations of particles. In addition, the velocity distribution in the transverse direction is symmetrical around zero, and it is slightly more intermittent than the random Gaussian curve due to particle-particle and particle-grain interactions. In contrast, as clogging develops, the longitudinal velocity of particles along the mean flow direction peaks near zero because of many trapped particles. But at the same time, the remaining open pores will experience larger pressure and, as a result, particles through those pores tend to have larger longitudinal velocities.

Red blood cells open promising avenues for longitudinal studies of ageing in laboratory, non-model and wild animals.

PubMed

Stier, Antoine; Reichert, Sophie; Criscuolo, Francois; Bize, Pierre

2015-11-01

Ageing is characterized by a progressive deterioration of multiple physiological and molecular pathways, which impair organismal performance and increase risks of death with advancing age. Hence, ageing studies must identify physiological and molecular pathways that show signs of age-related deterioration, and test their association with the risk of death and longevity. This approach necessitates longitudinal sampling of the same individuals, and therefore requires a minimally invasive sampling technique that provides access to the larger spectrum of physiological and molecular pathways that are putatively associated with ageing. The present paper underlines the interest in using red blood cells (RBCs) as a promising target for longitudinal studies of ageing in vertebrates. RBCs provide valuable information on the following six pathways: cell maintenance and turnover (RBC number, size, and heterogeneity), glucose homeostasis (RBC glycated haemoglobin), oxidative stress parameters, membrane composition and integrity, mitochondrial functioning, and telomere dynamics. The last two pathways are specific to RBCs of non-mammalian species, which possess a nucleus and functional mitochondria. We present the current knowledge about RBCs and age-dependent changes in these pathways in non-model and wild species that are especially suitable to address questions related to ageing using longitudinal studies. We discuss how the different pathways relate with survival and lifespan and give information on their genetic and environmental determinants to appraise their evolutionary potential. Copyright © 2015 Elsevier Inc. All rights reserved.

Longitudinal diffusion changes following postoperative delirium in older people without dementia.

PubMed

Cavallari, Michele; Dai, Weiying; Guttmann, Charles R G; Meier, Dominik S; Ngo, Long H; Hshieh, Tammy T; Fong, Tamara G; Schmitt, Eva; Press, Daniel Z; Travison, Thomas G; Marcantonio, Edward R; Jones, Richard N; Inouye, Sharon K; Alsop, David C

2017-09-05

To investigate the effect of postoperative delirium on longitudinal brain microstructural changes, as measured by diffusion tensor imaging. We studied a subset of the larger Successful Aging after Elective Surgery (SAGES) study cohort of older adults (≥70 years) without dementia undergoing elective surgery: 113 participants who had diffusion tensor imaging before and 1 year after surgery. Postoperative delirium severity and occurrence were assessed during the hospital stay using the Confusion Assessment Method and a validated chart review method. We investigated the association of delirium severity and occurrence with longitudinal diffusion changes across 1 year, adjusting for age, sex, vascular comorbidity, and baseline cognitive performance. We also assessed the association between changes in diffusion and cognitive performance across the 1-year follow-up period, adjusting for age, sex, education, and baseline cognitive performance. Postoperative delirium occurred in 25 participants (22%). Delirium severity and occurrence were associated with longitudinal diffusion changes in the periventricular, frontal, and temporal white matter. Diffusion changes were also associated with changes in cognitive performance across 1 year, although the cognitive changes did not show significant association with delirium severity or occurrence. Our study raises the possibility that delirium has an effect on the development of brain microstructural abnormalities, which may reflect brain changes underlying cognitive trajectories. Future studies are warranted to clarify whether delirium is the driving factor of the observed changes or rather a correlate of a vulnerable brain that is at high risk for neurodegenerative processes. © 2017 American Academy of Neurology.

Examining the Variability of Sleep Patterns during Treatment for Chronic Insomnia: Application of a Location-Scale Mixed Model

PubMed Central

Ong, Jason C.; Hedeker, Donald; Wyatt, James K.; Manber, Rachel

2016-01-01

Study Objectives: The purpose of this study was to introduce a novel statistical technique called the location-scale mixed model that can be used to analyze the mean level and intra-individual variability (IIV) using longitudinal sleep data. Methods: We applied the location-scale mixed model to examine changes from baseline in sleep efficiency on data collected from 54 participants with chronic insomnia who were randomized to an 8-week Mindfulness-Based Stress Reduction (MBSR; n = 19), an 8-week Mindfulness-Based Therapy for Insomnia (MBTI; n = 19), or an 8-week self-monitoring control (SM; n = 16). Sleep efficiency was derived from daily sleep diaries collected at baseline (days 1–7), early treatment (days 8–21), late treatment (days 22–63), and post week (days 64–70). The behavioral components (sleep restriction, stimulus control) were delivered during late treatment in MBTI. Results: For MBSR and MBTI, the pre-to-post change in mean levels of sleep efficiency were significantly larger than the change in mean levels for the SM control, but the change in IIV was not significantly different. During early and late treatment, MBSR showed a larger increase in mean levels of sleep efficiency and a larger decrease in IIV relative to the SM control. At late treatment, MBTI had a larger increase in the mean level of sleep efficiency compared to SM, but the IIV was not significantly different. Conclusions: The location-scale mixed model provides a two-dimensional analysis on the mean and IIV using longitudinal sleep diary data with the potential to reveal insights into treatment mechanisms and outcomes. Citation: Ong JC, Hedeker D, Wyatt JK, Manber R. Examining the variability of sleep patterns during treatment for chronic insomnia: application of a location-scale mixed model. J Clin Sleep Med 2016;12(6):797–804. PMID:26951414

Comparison of longitudinal excursion of a nerve-phantom model using quantitative ultrasound imaging and motion analysis system methods: A convergent validity study.

PubMed

Paquette, Philippe; El Khamlichi, Youssef; Lamontagne, Martin; Higgins, Johanne; Gagnon, Dany H

2017-08-01

Quantitative ultrasound imaging is gaining popularity in research and clinical settings to measure the neuromechanical properties of the peripheral nerves such as their capability to glide in response to body segment movement. Increasing evidence suggests that impaired median nerve longitudinal excursion is associated with carpal tunnel syndrome. To date, psychometric properties of longitudinal nerve excursion measurements using quantitative ultrasound imaging have not been extensively investigated. This study investigates the convergent validity of the longitudinal nerve excursion by comparing measures obtained using quantitative ultrasound imaging with those determined with a motion analysis system. A 38-cm long rigid nerve-phantom model was used to assess the longitudinal excursion in a laboratory environment. The nerve-phantom model, immersed in a 20-cm deep container filled with a gelatin-based solution, was moved 20 times using a linear forward and backward motion. Three light-emitting diodes were used to record nerve-phantom excursion with a motion analysis system, while a 5-cm linear transducer allowed simultaneous recording via ultrasound imaging. Both measurement techniques yielded excellent association ( r  = 0.99) and agreement (mean absolute difference between methods = 0.85 mm; mean relative difference between methods = 7.48 %). Small discrepancies were largely found when larger excursions (i.e. > 10 mm) were performed, revealing slight underestimation of the excursion by the ultrasound imaging analysis software. Quantitative ultrasound imaging is an accurate method to assess the longitudinal excursion of an in vitro nerve-phantom model and appears relevant for future research protocols investigating the neuromechanical properties of the peripheral nerves.

Radiation collimator and systems incorporating same

DOEpatents

Norman, Daren R [Idaho Falls, ID; Yoon, Woo Y [Idaho Falls, ID; Jones, James L [Idaho Falls, ID; Haskell, Kevin J [Idaho Falls, ID; Bennett, Brion D [Idaho Falls, ID; Tschaggeny, Charles W [Woods Cross, UT; Jones, Warren F [Idaho Falls, ID

2011-09-13

A collimator including a housing having disposed therein a shield element surrounding a converter core in which a photon beam is generated from electrons emanating from a linear accelerator. A beam channeler longitudinally adjacent the shield element has a beam aperture therethrough coaxially aligned with, and of the same diameter as, an exit bore of the converter core. A larger entry bore in the converter core is coaxial with, and longitudinally separated from, the exit bore thereof. Systems incorporating the collimator are also disclosed.

Lexical processing and distributional knowledge in sound-spelling mapping in a consistent orthography: A longitudinal study of reading and spelling in dyslexic and typically developing children.

PubMed

Marinelli, Chiara Valeria; Cellini, Pamela; Zoccolotti, Pierluigi; Angelelli, Paola

This study examined the ability to master lexical processing and use knowledge of the relative frequency of sound-spelling mappings in both reading and spelling. Twenty-four dyslexic and dysgraphic children and 86 typically developing readers were followed longitudinally in 3rd and 5th grades. Effects of word regularity, word frequency, and probability of sound-spelling mappings were examined in two experimental tasks: (a) spelling to dictation; and (b) orthographic judgment. Dyslexic children showed larger regularity and frequency effects than controls in both tasks. Sensitivity to distributional information of sound-spelling mappings was already detected by third grade, indicating early acquisition even in children with dyslexia. Although with notable differences, knowledge of the relative frequencies of sound-spelling mapping influenced both reading and spelling. Results are discussed in terms of their theoretical and empirical implications.

Does inequality erode social trust? Results from multilevel models of US states and counties.

PubMed

Fairbrother, Malcolm; Martin, Isaac W

2013-03-01

Previous research has argued that income inequality reduces people's trust in other people, and that declining social trust in the United States in recent decades has been due to rising levels of income inequality. Using multilevel models fitted to data from the General Social Survey, this paper substantially qualifies these arguments. We show that while people are less trusting in US states with higher income inequality, this association holds only cross-sectionally, not longitudinally; since the 1970s, states experiencing larger increases in inequality have not suffered systematically larger declines in trust. For counties, there is no statistically significant relationship either cross-sectionally or longitudinally. There is therefore only limited empirical support for the argument that inequality influences generalized social trust; and the declining trust of recent decades certainly cannot be attributed to rising inequality. Copyright © 2012 Elsevier Inc. All rights reserved.

Hyperthyroidism is a Risk Factor for Developing Adhesive Capsulitis of the Shoulder: A Nationwide Longitudinal Population-Based Study

PubMed Central

Huang, Shih-Wei; Lin, Jia-Wei; Wang, Wei-Te; Wu, Chin-Wen; Liou, Tsan-Hon; Lin, Hui-Wen

2014-01-01

The purpose of this study was to investigate the prevalence and risk of adhesive capsulitis among hyperthyroidism patients. The data were obtained from the Longitudinal Health Insurance Database 2005 (LHID 2005) in Taiwan, using 1 million participants and a prospective population-based 7-year cohort study of survival analysis. The ambulatory-care claim records of patients diagnosed according to the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes relating to hyperthyroidism between January 1, 2004 and December 31, 2007, were obtained. The prevalence and the adjusted hazard ratio (HR) of adhesive capsulitis among hyperthyroid patients and the control group were estimated. Of 4472 hyperthyroid patients, 162 (671/100 000 person-years) experienced adhesive capsulitis during the 24 122 person-year follow-up period. The crude HR of stroke was 1.26 (95% confidence interval [CI], 1.06 to 1.49), which was larger than that of the control group. The adjusted HR of developing adhesive capsulitis was 1.22 (95% CI, 1.03 to 1.45) for hyperthyroid patients during the 7-year follow-up period, which achieved statistical significance. The results of our large-scale longitudinal population-based study indicated that hyperthyroidism is an independent risk factor of developing adhesive capsulitis. PMID:24567049

Hyperthyroidism is a risk factor for developing adhesive capsulitis of the shoulder: a nationwide longitudinal population-based study.

PubMed

Huang, Shih-Wei; Lin, Jia-Wei; Wang, Wei-Te; Wu, Chin-Wen; Liou, Tsan-Hon; Lin, Hui-Wen

2014-02-25

The purpose of this study was to investigate the prevalence and risk of adhesive capsulitis among hyperthyroidism patients. The data were obtained from the Longitudinal Health Insurance Database 2005 (LHID 2005) in Taiwan, using 1 million participants and a prospective population-based 7-year cohort study of survival analysis. The ambulatory-care claim records of patients diagnosed according to the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes relating to hyperthyroidism between January 1, 2004 and December 31, 2007, were obtained. The prevalence and the adjusted hazard ratio (HR) of adhesive capsulitis among hyperthyroid patients and the control group were estimated. Of 4472 hyperthyroid patients, 162 (671/100,000 person-years) experienced adhesive capsulitis during the 24,122 person-year follow-up period. The crude HR of stroke was 1.26 (95% confidence interval [CI], 1.06 to 1.49), which was larger than that of the control group. The adjusted HR of developing adhesive capsulitis was 1.22 (95% CI, 1.03 to 1.45) for hyperthyroid patients during the 7-year follow-up period, which achieved statistical significance. The results of our large-scale longitudinal population-based study indicated that hyperthyroidism is an independent risk factor of developing adhesive capsulitis.

Experimental study on titanium wire drawing with ultrasonic vibration.

PubMed

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

2018-02-01

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

Longitudinal safety evaluation of electric vehicles with the partial wireless charging lane on freeways.

PubMed

Li, Ye; Wang, Wei; Xing, Lu; Fan, Qi; Wang, Hao

2018-02-01

As an environment friendly transportation mode, the electric vehicle (EV) has drawn an increasing amount of attention from governments, vehicle manufactories and researchers recently. One of the biggest issue impeding EV's popularization associates with the charging process. The wireless charging lane (WCL) has been proposed as a convenient charging facility for EVs. Due to the high costs, the application of WCL on the entire freeways is impractical in the near future, while the partial WCL (PWCL) may be a feasible solution. This study aims to evaluate longitudinal safety of EVs with PWCL on freeways based on simulations. The simulation experiments are firstly designed, including deployment of PWCL on freeways and distribution of state of charge (SOC) of EVs. Then, a vehicle behavior model for EVs is proposed based on the intelligent driver model (IDM). Two surrogate safety measures, derived from time-to-collision (TTC), are utilized as indicators for safety evaluations. Sensitivity analysis is also conducted for related factors. Results show that the distribution of EVs' SOC significantly affect longitudinal safety when the PWCL is utilized. The low SOC in traffic consisting of EVs has the negative effect on longitudinal safety. The randomness and incompliance of EV drivers worsens the safety performance. The sensitivity analysis indicates that the larger maximum deceleration rate results in the higher longitudinal crash risks of EVs, while the length of PWCL has no monotonous effect. Different TTC thresholds also show no impact on results. A case study shows the consistent results. Based on the findings, several suggestions are discussed for EVs' safety improvement. Results of this study provide useful information for freeway safety when EVs are applied in the future. Copyright © 2017 Elsevier Ltd. All rights reserved.

Pilot expertise and hippocampal size: associations with longitudinal flight simulator performance.

PubMed

Adamson, Maheen M; Bayley, Peter J; Scanlon, Blake K; Farrell, Michelle E; Hernandez, Beatriz; Weiner, Michael W; Yesavage, Jerome A; Taylor, Joy L

2012-09-01

Previous research suggests that the size of the hippocampus can vary in response to intensive training (e.g., during the acquisition of expert knowledge). However, the role of the hippocampus in maintenance of skilled performance is not well understood. The Stanford/Veterans Affairs Aviation MRI Study offers a unique opportunity to observe the interaction of brain structure and multiple levels of expertise on longitudinal flight simulator performance. The current study examined the relationship between hippocampal volume and three levels of aviation expertise, defined by pilot proficiency ratings issued by the U.S. Federal Aviation Administration (11). At 3 annual time points, 60 pilots who varied in their level of aviation expertise (ages ranging from 45 to 69 yr) were tested. At baseline, higher expertise was associated with better flight simulator performance, but not with hippocampal volume. Longitudinally, there was an Expertise x Hippocampal volume interaction, in the direction that a larger hippocampus was associated with better performance at higher levels of expertise. These results are consistent with the notion that expertise in a cognitively demanding domain involves the interplay of acquired knowledge ('mental schemas') and basic hippocampal-dependent processes.

Progressive attenuation of the longitudinal kinetics in the common carotid artery: preliminary in vivo assessment.

PubMed

Zahnd, Guillaume; Balocco, Simone; Sérusclat, André; Moulin, Philippe; Orkisz, Maciej; Vray, Didier

2015-01-01

Longitudinal kinetics (LOKI) of the arterial wall consists of the shearing motion of the intima-media complex over the adventitia layer in the direction parallel to the blood flow during the cardiac cycle. The aim of this study was to investigate the local variability of LOKI amplitude along the length of the vessel. By use of a previously validated motion-estimation framework, 35 in vivo longitudinal B-mode ultrasound cine loops of healthy common carotid arteries were analyzed. Results indicated that LOKI amplitude is progressively attenuated along the length of the artery, as it is larger in regions located on the proximal side of the image (i.e., toward the heart) and smaller in regions located on the distal side of the image (i.e., toward the head), with an average attenuation coefficient of -2.5 ± 2.0%/mm. Reported for the first time in this study, this phenomenon is likely to be of great importance in improving understanding of atherosclerosis mechanisms, and has the potential to be a novel index of arterial stiffness. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Analysis of in-trail following dynamics of CDTI-equipped aircraft. [Cockpit Displays of Traffic Information

NASA Technical Reports Server (NTRS)

Sorensen, J. A.; Goka, T.

1982-01-01

In connection with the necessity to provide greater terminal area capacity, attention is given to approaches in which the required increase in capacity will be obtained by making use of more automation and by involving the pilot to a larger degree in the air traffic control (ATC) process. It was recommended that NASA should make extensive use of its research aircraft and cockpit simulators to assist the FAA in examining the capabilities and limitations of cockpit displays of traffic information (CDTI). A program was organized which utilizes FAA ATC (ground-based) simulators and NASA aircraft and associated cockpit simulators in a research project which explores applications of the CDTI system. The present investigation is concerned with several questions related to the CDTI-based terminal area traffic tactical control concepts. Attention is given to longitudinal separation criteria, a longitudinal following model, longitudinal capture, combined longitudinal/vertical control, and lateral control.

Scaling in Theropod Dinosaurs: Femoral Bone Strength and Locomotion

NASA Astrophysics Data System (ADS)

Lee, Scott

2015-02-01

In our first article1 on scaling in theropod dinosaurs, the longitudinal stress in the leg bones due to supporting the weight of the animal was studied and found not to control the dimensions of the femur. As a continuation of our study of elasticity in dinosaur bones, we now examine the transverse stress in the femur due to locomotion and find that this effect is important for the geometry of the bone. We find that larger theropods (including Tyrannosaurus rex) were less athletic than smaller theropods.

A Longitudinal Examination of Positive Parenting Following an Acceptance-Based Couple Intervention

PubMed Central

Morrill, Melinda Ippolito; Hawrilenko, Matt; Córdova, James V.

2015-01-01

Positive parenting practices have been shown to be essential for healthy child development, and yet have also been found to be particularly challenging for parents to enact and maintain. This paper explores an innovative approach for increasing positive parenting by targeting specific positive emotional processes within marital relationships. Couple emotional acceptance is a powerful mechanism that has repeatedly been found to improve romantic relationships, but whether these effects extend to the larger family environment is less well understood. The current longitudinal study examined the role of improved levels of acceptance in mother’s and father’s positive parenting after a couple intervention. Participants included 244 parents (122 couples) in the Marriage Checkup (MC) study, a randomized, controlled, acceptance-based, intervention study. Data indicated that both women and men experienced significantly greater felt acceptance two-weeks after the MC intervention, treatment women demonstrated greater positive parenting two weeks after the intervention, and all treatment participants’ positive parenting was better maintained than control couple’s six months later. Importantly, although mothers’ positive parenting was not influenced by different levels of felt acceptance, changes in father’s positive parenting were positively associated with changes in felt acceptance. As men felt more accepted by their wives, their levels of positive parenting changed in kind, and this effect on positive parenting was found to be mediated by felt acceptance two weeks after the MC. Overall, findings supported the potential benefits of targeting couple acceptance to generate positive cascades throughout the larger family system. PMID:26551659

An observation of lower rates of drug use over time in community syringe exchangers.

PubMed

Kidorf, Michael; King, Van L; Peirce, Jessica; Kolodner, Ken; Brooner, Robert K

2013-01-01

The present study evaluated changes in rates of self-reported heroin and cocaine use in opioid-dependent individuals newly registered to a syringe exchange program (SEP), and examined the effects of recovery-oriented longitudinal variables (i.e., substance abuse treatment, self-help group participation, employment) on changes in drug use. Study participants (n = 240) were opioid-dependent and drawn from a larger study evaluating strategies to improve treatment-seeking. Mixed model analyses were used to evaluate changes in rates of heroin and cocaine use, and longitudinal correlates of change in these substances, over a one-year period. Results showed reductions in days of heroin and cocaine use over time, and that participation in recovery-oriented activities was strongly associated with greater changes in drug use. These results suggest SEPs can play a vital role in facilitating reductions in drug use through motivating participation in treatment and other recovery-oriented activities. Copyright © American Academy of Addiction Psychiatry.

Decreasing initial telomere length in humans intergenerationally understates age-associated telomere shortening

PubMed Central

Holohan, Brody; De Meyer, Tim; Batten, Kimberly; Mangino, Massimo; Hunt, Steven C; Bekaert, Sofie; De Buyzere, Marc L; Rietzschel, Ernst R; Spector, Tim D; Wright, Woodring E; Shay, Jerry W

2015-01-01

Telomere length shortens with aging, and short telomeres have been linked to a wide variety of pathologies. Previous studies suggested a discrepancy in age-associated telomere shortening rate estimated by cross-sectional studies versus the rate measured in longitudinal studies, indicating a potential bias in cross-sectional estimates. Intergenerational changes in initial telomere length, such as that predicted by the previously described effect of a father’s age at birth of his offspring (FAB), could explain the discrepancy in shortening rate measurements. We evaluated whether changes occur in initial telomere length over multiple generations in three large datasets and identified paternal birth year (PBY) as a variable that reconciles the difference between longitudinal and cross-sectional measurements. We also clarify the association between FAB and offspring telomere length, demonstrating that this effect is substantially larger than reported in the past. These results indicate the presence of a downward secular trend in telomere length at birth over generational time with potential public health implications. PMID:25952108

A Three-Year Longitudinal Study of Reading and Spelling Difficulty in Chinese Developmental Dyslexia: The Matter of Morphological Awareness.

PubMed

Tong, Xiuhong; McBride, Catherine; Lo, Jason Chor Ming; Shu, Hua

2017-11-01

In the present study, we used a three-time point longitudinal design to investigate the associations of morphological awareness to word reading and spelling in a small group of those with and without dyslexia taken from a larger sample of 164 Hong Kong Chinese children who remained in a longitudinal study across ages 6, 7 and 8. Among those 164 children, 15 had been diagnosed as having dyslexia by professional psychologists, and 15 other children manifested average reading ability and had been randomly selected from the sample for comparison. All children were administered a battery of tasks including Chinese character recognition, word dictation, morphological awareness, phonological awareness and rapid automatized naming. Multivariate analysis of variance and predictive discriminate analysis were performed to examine whether the dyslexic children showed differences in the cognitive-linguistic tasks in comparison with controls. Results suggested that the dyslexic groups had poorer performance in morphological awareness and RAN across all 3 years. However, phonological awareness was not stable in distinguishing the groups. Findings suggest that morphological awareness is a relatively strong correlate of spelling difficulties in Chinese, but phonological awareness is not. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

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

PubMed

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

2015-08-01

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

X-ray measurements of the strain and shape of dielectric/metallic wrap-gated InAs nanowires

NASA Astrophysics Data System (ADS)

Eymery, J.; Favre-Nicolin, V.; Fröberg, L.; Samuelson, L.

2009-03-01

Wrap-gate (111) InAs nanowires (NWs) were studied after HfO2 dielectric coating and Cr metallic deposition by a combination of grazing incidence x-ray techniques. In-plane and out-of-plane x-ray diffraction (crystal truncation rod analysis) allow determining the strain tensor. The longitudinal contraction, increasing with HfO2 and Cr deposition, is significantly larger than the radial dilatation. For the Cr coating, the contraction along the growth axis is quite large (-0.95%), and the longitudinal/radial deformation ratio is >10, which may play a role on the NW transport properties. Small angle x-ray scattering shows a smoothening of the initial hexagonal bare InAs NW shape and gives the respective core/shell thicknesses, which are compared to flat surface values.

Mapping the dominant regions of the phase space associated with c c ¯ production relevant for the prompt atmospheric neutrino flux

NASA Astrophysics Data System (ADS)

Goncalves, Victor P.; Maciuła, Rafał; Pasechnik, Roman; Szczurek, Antoni

2017-11-01

We present a detailed mapping of the dominant kinematical domains contributing to the prompt atmospheric neutrino flux at high neutrino energies by studying their sensitivity to the cuts on several kinematical variables crucial for charm production in cosmic ray scattering in the atmosphere. This includes the maximal center-of-mass energy for proton-proton scattering, the longitudinal momentum fractions of partons in the projectile (cosmic ray) and target (nucleus of the atmosphere), the Feynman xF variable, and the transverse momentum of charm quark/antiquark. We find that the production of neutrinos with energies larger than Eν>107 GeV is particularly sensitive to the c.m. energies larger than the ones at the LHC and to the longitudinal momentum fractions in the projectile 10-8

Effect of wall pattern configurations on Stokes flow through a microchannel with superhydrophobic slip

NASA Astrophysics Data System (ADS)

Mak, H. M.; Ng, C. O.

2010-11-01

The present work aims to study low-Reynolds-number flow through a microchannel with superhydrophobic surfaces, which contain a periodic array of parallel ribs on the upper and lower walls. Mimicking impregnation, the liquid is allowed to penetrate the grooves between the ribs which are filled with an inviscid gas. The array of ribs and grooves gives a heterogeneous wall boundary condition to the channel flow, with partial-slip boundary condition on the solid surface and no-shear boundary condition on the liquid-gas interface. Using the method of eigenfunction expansions and domain decomposition, semi-analytical models are developed for four configurations. Two of them are for longitudinal flow and the others are for transverse flow. For each flow orientation, in-phase and out-phase alignments of ribs between the upper and lower walls are analyzed. The effect of the phase alignments of ribs is appreciable when the channel height is sufficiently small. In-phase alignment gives rise to a larger effective slip length in longitudinal flow. On the contrary, out-phase alignment will yield a larger effective slip length in transverse flow. This work was supported by the Research Grants Council of the Hong Kong Special Administrative Region, China, through Project HKU 7156/09E.

Rate of radial transport of plasma in Saturn’s inner magnetosphere

NASA Astrophysics Data System (ADS)

Chen, Y.; Hill, T. W.

2009-12-01

The Cassini Plasma Spectrometer (CAPS) and the Cassini Magnetospheric Imaging Instrument (MIMI) frequently observe longitudinally localized injection and drift dispersion of hot plasma in Saturn’s magnetosphere. These signatures provide direct evidence for the major convective process in the inner magnetosphere of a rapidly rotating planet, in which the radial transport of plasma comprises hot, tenuous plasma moving inward and cooler, denser plasma moving outward. These injection events have been found to occupy only a small fraction of the total available longitudinal space, indicating that the inflow speed is probably much larger than the outflow speed. We set the local corotation speed as the upper limit of inflow velocities, and deduce the corresponding radial velocities of the outflowing flux tubes by analyzing the width of injection structures and assuming that the total potential drop around a given L-shell is zero. We then estimate an upper limit to the plasma outward mass transport rate, which turns out to be somewhat larger than previous estimates of the Enceladus source rate (e.g., Pontius and Hill, 2006). An important assumption in this study is that the plasma is largely confined to a thin equatorial sheet, and we have applied a centrifugal scale height model developed by Hill and Michel [1976].

PHYSICAL PROPERTIES OF LARGE AND SMALL GRANULES IN SOLAR QUIET REGIONS

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

Yu Daren; Xie Zongxia; Hu Qinghua

The normal mode observations of seven quiet regions obtained by the Hinode spacecraft are analyzed to study the physical properties of granules. An artificial intelligence technique is introduced to automatically find the spatial distribution of granules in feature spaces. In this work, we investigate the dependence of granular continuum intensity, mean Doppler velocity, and magnetic fields on granular diameter. We recognized 71,538 granules by an automatic segmentation technique and then extracted five properties: diameter, continuum intensity, Doppler velocity, and longitudinal and transverse magnetic flux density to describe the granules. To automatically explore the intrinsic structures of the granules in themore » five-dimensional parameter space, the X-means clustering algorithm and one-rule classifier are introduced to define the rules for classifying the granules. It is found that diameter is a dominating parameter in classifying the granules and two families of granules are derived: small granules with diameters smaller than 1.''44, and large granules with diameters larger than 1.''44. Based on statistical analysis of the detected granules, the following results are derived: (1) the averages of diameter, continuum intensity, and Doppler velocity in the upward direction of large granules are larger than those of small granules; (2) the averages of absolute longitudinal, transverse, and unsigned flux density of large granules are smaller than those of small granules; (3) for small granules, the average of continuum intensity increases with their diameters, while the averages of Doppler velocity, transverse, absolute longitudinal, and unsigned magnetic flux density decrease with their diameters. However, the mean properties of large granules are stable; (4) the intensity distributions of all granules and small granules do not satisfy Gaussian distribution, while that of large granules almost agrees with normal distribution with a peak at 1.04 I{sub 0}.« less

Systematically Asymmetric Heliospheric Magnetic Field: Evidence for a Quadrupole Mode and Non-Axisymmetry with Polarity Flip-Flops

NASA Astrophysics Data System (ADS)

Mursula, K.; Hiltula, T.

2004-10-01

Recent studies of the heliospheric magnetic field (HMF) have detected interesting, systematic hemispherical and longitudinal asymmetries which have a profound significance for the understanding of solar magnetic fields. The in situ HMF measurements since the 1960s show that the heliospheric current sheet (HCS) is systematically shifted (coned) southward during solar minimum times, leading to the concept of a bashful ballerina. While temporary shifts can be considerably larger, the average HCS shift (coning) angle is a few degrees, less than the 7.2∘ tilt of the solar rotation axis. Recent solar observations during the last two solar cycles verify these results and show that the magnetic areas in the northern solar hemisphere are larger and their intensity weaker than in the south during long intervals in the late declining to minimum phase. The multipole expansion reveals a strong quadrupole term which is oppositely directed to the dipole term. These results imply that the Sun has a symmetric quadrupole S0 dynamo mode that oscillates in phase with the dominant dipole A0 mode. Moreover, the heliospheric magnetic field has a strong tendency to produce solar tilts that are roughly opposite in longitudinal phase. This implies is a systematic longitudinal asymmetry and leads to a “flip-flop” type behaviour in the dominant HMF sector whose period is about 3.2 years. This agrees very well with the similar flip-flop period found recently in sunspots, as well as with the observed ratio of three between the activity cycle period and the flip-flop period of sun-like stars. Accordingly, these results require that the solar dynamo includes three modes, A0, S0 and a non-axisymmetric mode. Obviously, these results have a great impact on solar modelling.

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

PubMed

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

2012-09-01

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

Breastfeeding and Childhood IQ: The Mediating Role of Gray Matter Volume.

PubMed

Luby, Joan L; Belden, Andy C; Whalen, Diana; Harms, Michael P; Barch, Deanna M

2016-05-01

A substantial body of literature has established the positive effect of breastfeeding on child developmental outcomes. There is increasing consensus that breastfed children have higher IQs after accounting for key variables, including maternal education, IQ, and socioeconomic status. Cross-sectional investigations of the effects of breastfeeding on structural brain development suggest that breastfed infants have larger whole brain, cortical, and white matter volumes. To date, few studies have related these measures of brain structure to IQ in breastfed versus nonbreastfed children in a longitudinal sample. Data were derived from the Preschool Depression Study (PDS), a prospective longitudinal study in which children and caregivers were assessed annually for 8 waves over 11 years. A subset completed neuroimaging between the ages of 9.5 and 14.11 years. A total of 148 individuals had breastfeeding data at baseline and complete data on all variables of interest, including IQ and structural neuroimaging. General linear models and process mediation models were used. Breastfed children had significantly higher IQ scores and larger whole brain, total gray matter, total cortical gray matter, and subcortical gray matter volumes compared with the nonbreastfed group in models that covaried for key variables. Subcortical gray matter volume significantly mediated the association between breastfeeding and children's IQ scores. The study findings suggest that the effects of breastfeeding on child IQ are mediated through subcortical gray volume. This effect and putative mechanism is of public health significance and further supports the importance of breastfeeding in mental health promotion. Copyright © 2016 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

Breastfeeding and Childhood IQ: The Mediating Role of Gray Matter Volume

PubMed Central

Luby, Joan L.; Belden, Andy C.; Whalen, Diana; Harms, Michael P.; Barch, Deanna M.

2016-01-01

Objective A substantial body of literature has established the positive effect of breastfeeding on child developmental outcomes. There is increasing consensus that breastfed children have higher IQs after accounting for key variables, including maternal education, IQ, and socioeconomic status. Cross-sectional investigations of the effects of breastfeeding on structural brain development suggest that breastfed infants have larger whole brain, cortical, and white matter volumes. To date, few studies have related these measures of brain structure to IQ in breastfed versus nonbreastfed children in a longitudinal sample. Method Data were derived from the Preschool Depression Study (PDS), a prospective longitudinal study in which children and caregivers were assessed annually for 8 waves over 11 years. A subset completed neuroimaging between the ages of 9.5 and 14.11 years. A total of 148 individuals had breastfeeding data at baseline and complete data on all variables of interest, including IQ and structural neuroimaging. General linear models and process mediation models were used. Results Breastfed children had significantly higher IQ scores and larger whole brain, total gray matter, total cortical gray matter, and subcortical gray matter volumes compared with the nonbreastfed group in models that covaried for key variables. Subcortical gray matter volume significantly mediated the association between breast-feeding and children's IQ scores. Conclusion The study findings suggest that the effects of breastfeeding on child IQ are mediated through subcortical gray volume. This effect and putative mechanism is of public health significance and further supports the importance of breastfeeding in mental health promotion. PMID:27126850

In vivo longitudinal chromatic aberration of pseudophakic eyes.

PubMed

Siedlecki, Damian; Jóźwik, Agnieszka; Zając, Marek; Hill-Bator, Aneta; Turno-Kręcicka, Anna

2014-02-01

To present the results of longitudinal chromatic aberration measurements on two groups of pseudophakic eyes in comparison to healthy eyes. The longitudinal chromatic aberration of the eye, defined as chromatic difference of refraction with disabled accommodation, was measured with the use of a visual refractometer with a custom-designed target illuminator consisting of a narrow-band RGB diode (blue λb = 470 ± 15 nm; green λg = 525 ± 18 nm; red λr = 660 ± 10 nm). The measurements were performed on nine eyes implanted with AcrySof IQ SN60WF, 14 eyes implanted with AcrySof SA60AT, and 10 phakic eyes under cycloplegia. The mean values of the longitudinal chromatic aberration between 470 and 660 nm for the control group was 1.12 ± 0.14 D. For SA60AT group, it was 1.45 ± 0.42 D whereas for SN60WF it was 1.17 ± 0.52 D. The statistical test showed significant difference between SA60AT and the control group (p < 0.05) and no significant difference between SN60WF and the control groups (p = 0.64). The study showed that the longitudinal chromatic aberration in vivo can be easily and reliably estimated with an adapted visual refractometer. The two groups of pseudophakic eyes measured in this study showed different values of chromatic aberration. Its magnitude for SA60AT group was significantly larger than for the control group whereas for SN60WF the difference was not significant. The optical material used for intraocular lens design may have significant influence on the magnitude of the chromatic aberration of the pseudophakic eye, and therefore on its optical and visual performance in polychromatic light.

Longitudinal Trajectories of Aberrant Behavior in Fragile X Syndrome

PubMed Central

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

2016-01-01

The Aberrant Behavior Checklist—Community (ABC-C; Aman, Burrow, & Wolford, 1995) has been increasingly adopted as a primary tool for measuring behavioral change in clinical trials for individuals with fragile X syndrome (FXS). To our knowledge, however, no study has documented the longitudinal trajectory of aberrant behaviors in individuals with FXS using the ABC-C. As part of a larger longitudinal study, we examined scores obtained on the ABC-C subscales for 124 children and adolescents (64 males, 60 females) with FXS who had two or more assessments (average interval between assessments was approximately 4 years). Concomitant changes in age-equivalent scores on the Vineland Adaptive Behavior Scales (VABS) were also examined. As expected for an X-linked genetic disorder, males with FXS obtained significantly higher scores on all subscales of the ABC-C and significantly lower age-equivalent scores on the VABS than females with FXS. In both males and females with FXS, scores on the Irritability/Agitation and Hyperactivity/Noncompliance subscales of the ABC-C decreased significantly with age, with little to no change occurring over time on the Lethargy/Social Withdrawal, Stereotypic Behavior, and Inappropriate Speech subscales. The decrease in scores on the Hyperactivity/Noncompliance domain was significantly greater for males than for females. In both males and females, age-equivalent scores on the VABS increased significantly over this developmental period. These results establish a basis upon which to evaluate long-term outcomes from intervention-based research. However, longitudinal direct observational studies are needed to establish whether the severity of problem behavior actually decreases over time in this population. PMID:25129200

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

PubMed

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

2018-04-26

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

Does functional disability mediate the pain-depression relationship in older adults with osteoarthritis? A longitudinal study in China.

PubMed

Wang, Qian; Jayasuriya, Rohan; Man, Wing Young Nicola; Fu, Hua

2015-03-01

Older adults with osteoarthritis have been found to be impaired in physical functioning and report higher levels of depression. This study examined the relationships between pain, functional disability, and depression to test the activity restriction model in a cohort of 176 older adults in China. This model states that disability is a mediator for the relationship between pain and depression. Other investigators have found that pain and disability were two independent correlates of depression. In both cross-sectional and longitudinal analyses, the authors found that disability is a mediator, using commonly accepted methods (indirect effect 44%, Sobel Z = 4.07, P < .001; 41%, Sobel Z = 3.45, P < .001, respectively). However, this mediation effect was not seen when the outcome was residualized with the baseline value. When the baseline level of depression is residualized, the effect size of the relationship is reduced, requiring larger sample size to test its effect. © 2012 APJPH.

Divorce, approaches to learning, and children's academic achievement: a longitudinal analysis of mediated and moderated effects.

PubMed

Anthony, Christopher J; DiPerna, James Clyde; Amato, Paul R

2014-06-01

Data from the Early Childhood Longitudinal Study--Kindergarten Cohort (ECLS-K) were used to test the hypothesis that approaches to learning (ATL) mediates the link between parental divorce and academic achievement. Fixed effects regression was utilized to test for mediation, and subsequent moderation analyses examining gender and age at time of divorce also were conducted. Results indicated that divorce was associated with less growth in test scores and that ATL mediated 18% and 12% of this association in reading and mathematics respectively. Parental divorce also was associated with larger negative effects for children who experienced divorce at an older age as well as for girls' mathematics test scores. These findings contribute to the understanding of the impact of parental divorce on children's academic achievement and underscore the importance of focusing on the variability of child outcomes following parental divorce. Copyright © 2014 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

Nonlinear panel flutter in a rarefied atmosphere - Aerodynamic shear stress effects

NASA Technical Reports Server (NTRS)

Resende, Hugo B.

1991-01-01

The panel flutter phenomenon is studied assuming free-molecule flow. This kind of analysis is relevant in the case of hypersonic flight vehicles traveling at high altitudes, especially in the leeward portion of the vehicle. In these conditions the aerodynamic shear can be expected to be considerably larger than the pressure at a given point, so that the effects of such a loading are incorporated into the structural model. This is accomplished by introducing distributed longitudinal and bending moment loads. The former can lead to buckling of the panel, with the second mode in the case of a simply-supported panel playing a important role, and becoming the dominant mode in the solution. The presence of equivalent springs in the longitudinal direction at the panel's ends also becomes of relative importance, even for the evaluation of the linear flutter parameter. Finally, the behavior of the system is studied in the presence of applied compressive forces, that is, classical buckling.

The effect of income and occupation on body mass index among women in the Cebu Longitudinal Health and Nutrition Surveys (1983-2002).

PubMed

Colchero, M Arantxa; Caballero, Benjamin; Bishai, David

2008-05-01

We assessed the effects of changes in income and occupational activities on changes in body weight among 2952 non-pregnant women enrolled in the Cebu Longitudinal Health and Nutrition Surveys between 1983 and 2002. On average, body mass index (BMI) among women occupied in low activities was 0.29 kg/m(2) (standard error 0.11) larger compared to women occupied in heavy activities. BMI among women involved in medium activities was on average 0.12 kg/m(2) (standard error 0.05) larger compared to women occupied in heavy activities. A one-unit increase in log household income in the previous survey was associated with a small and positive change in BMI of 0.006 kg/m(2) (standard error 0.02) but the effect was not significant. The trend of increasing body mass was higher in the late 1980s than during the 1990s. These period effects were stronger for the women who were younger at baseline and for women with low or medium activity levels. Our analysis suggests a trend in the environment over the last 20 years that has increased the susceptibility of Filipino women to larger body mass.

Accuracy and Landmark Error Calculation Using Cone-Beam Computed Tomography–Generated Cephalograms

PubMed Central

Grauer, Dan; Cevidanes, Lucia S. H.; Styner, Martin A.; Heulfe, Inam; Harmon, Eric T.; Zhu, Hongtu; Proffit, William R.

2010-01-01

Objective To evaluate systematic differences in landmark position between cone-beam computed tomography (CBCT)–generated cephalograms and conventional digital cephalograms and to estimate how much variability should be taken into account when both modalities are used within the same longitudinal study. Materials and Methods Landmarks on homologous cone-beam computed tomographic–generated cephalograms and conventional digital cephalograms of 46 patients were digitized, registered, and compared via the Hotelling T2 test. Results There were no systematic differences between modalities in the position of most landmarks. Three landmarks showed statistically significant differences but did not reach clinical significance. A method for error calculation while combining both modalities in the same individual is presented. Conclusion In a longitudinal follow-up for assessment of treatment outcomes and growth of one individual, the error due to the combination of the two modalities might be larger than previously estimated. PMID:19905853

Spin-orbit torque in a bulk perpendicular magnetic anisotropy Pd/FePd/MgO system

PubMed Central

Lee, Hwang-Rae; Lee, Kyujoon; Cho, Jaehun; Choi, Young-Ha; You, Chun-Yeol; Jung, Myung-Hwa; Bonell, Frédéric; Shiota, Yoichi; Miwa, Shinji; Suzuki, Yoshishige

2014-01-01

Spin-orbit torques, including the Rashba and spin Hall effects, have been widely observed and investigated in various systems. Since interesting spin-orbit torque (SOT) arises at the interface between heavy nonmagnetic metals and ferromagnetic metals, most studies have focused on the ultra-thin ferromagnetic layer with interface perpendicular magnetic anisotropy. Here, we measured the effective longitudinal and transverse fields of bulk perpendicular magnetic anisotropy Pd/FePd (1.54 to 2.43 nm)/MgO systems using harmonic methods with careful correction procedures. We found that in our range of thicknesses, the effective longitudinal and transverse fields are five to ten times larger than those reported in interface perpendicular magnetic anisotropy systems. The observed magnitude and thickness dependence of the effective fields suggest that the SOT do not have a purely interfacial origin in our samples. PMID:25293693

RHIC Au beam in Run 2014

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

Zhang, S. Y.

Au beam at the RHIC ramp in run 2014 is reviewed together with the run 2011 and run 2012. Observed bunch length and longitudinal emittance are compared with the IBS simulations. The IBS growth rate of the longitudinal emittance in run 2014 is similar to run 2011, and both are larger than run 2012. This is explained by the large transverse emittance at high intensity observed in run 2012, but not in run 2014. The big improvement of the AGS ramping in run 2014 might be related to this change. The importance of the injector intensity improvement in run 2014more » is emphasized, which gives rise to the initial luminosity improvement of 50% in run 2014, compared with the previous Au-Au run 2011. In addition, a modified IBS model, which is calibrated using the RHIC Au runs from 9.8 GeV/n to 100 GeV/n, is presented and used in the study.« less

Anterior Cortical Development During Adolescence in Bipolar Disorder

PubMed Central

Najt, Pablo; Wang, Fei; Spencer, Linda; Johnston, Jennifer A.Y.; Cox Lippard, Elizabeth T.; Pittman, Brian P.; Lacadie, Cheryl; Staib, Lawrence H.; Papademetris, Xenophon; Blumberg, Hilary P.

2015-01-01

Background Increasing evidence supports a neurodevelopmental model for bipolar disorder (BD), with adolescence as a critical period in its development. Developmental abnormalities of anterior paralimbic and heteromodal frontal cortices, key structures in emotional regulation processes and central in BD, are implicated. However, few longitudinal studies have been conducted, limiting understanding of trajectory alterations in BD. In this study, we performed longitudinal neuroimaging of adolescents with and without BD and assessed volume changes over time, including changes in tissue overall and within gray and white matter. Larger decreases over time in anterior cortical volumes in the adolescents with BD were hypothesized. Gray matter decreases and white matter increases are typically observed during adolescence in anterior cortices. It was hypothesized that volume decreases over time in BD would reflect alterations in those processes, showing larger gray matter contraction and decreased white matter expansion. Methods Two high-resolution magnetic resonance imaging scans were obtained approximately two-years apart for 35 adolescents with BDI and 37 healthy adolescents. Differences over time between groups were investigated for volume overall and specifically for gray and white matter. Results Relative to healthy adolescents, adolescents with BDI showed greater volume contraction over time in a region including insula, and orbitofrontal, rostral and dorsolateral prefrontal cortices (P<.05, corrected), including greater gray matter contraction and decreased white matter expansion over time, in the BD compared to the healthy group. Conclusions: The findings support neurodevelopmental abnormalities during adolescence in BDI in anterior cortices, include altered developmental trajectories of anterior gray and white matter. PMID:26033826

Complicating the "soccer mom:"the cultural politics of forming class-based identity, distinction, and necessity.

PubMed

Swanson, Lisa

2009-06-01

Using Pierre Bourdieu's theories of social class differentiation and class reproduction, this paper provides an analysis of class-based identity politics in contemporary suburban America. Through a critical ethnography of the emergent, American, upper-middle-class "soccer mom" phenomenon, this study contributes to a growing body of research that interrogates class-based, cultural practices of status differentiation. As part of a larger; longitudinal ethnographic study, this paper specifically focuses on the ways in which women, who are driven by upper-middle-class habitus, contest and construct their identity as mothers of young, soccer-playing children.

Comparative Analysis of the Mini-pterional and Supraorbital Keyhole Craniotomies for Unruptured Aneurysms with Numeric Measurements of Their Geometric Configurations.

PubMed

Kang, Ho-Jun; Lee, Yoon-Soo; Suh, Sang-Jun; Lee, Jeong-Ho; Ryu, Kee-Young; Kang, Dong-Gee

2013-03-01

Keyhole craniotomy is a modification of pterional craniotomy that allows for use of a minimally invasive approach toward cerebral aneurysms. Currently, mini-pterional (MPKC) and supraorbital keyhole craniotomies (SOKC) are commonly used. In this study, we measured and compared the geometric configurations of surgical exposure provided by MPKC and SOKC. Nine patients underwent MPKC and four underwent SOKC. Their postoperative contrast-enhanced brain computed tomographic scans were evaluated. The transverse and longitudinal diameters and areas of exposure were measured. The locations of the anterior communicating artery, bifurcation of the middle cerebral artery (MCAB), and the internal carotid artery (ICA) terminal were identified, and the working angles and depths for these targets were measured. No significant differences in the transverse diameters of exposure were observed between MPKC and SOKC. However, the longitudinal diameters and the areas were significantly larger, by 1.5 times in MPKC. MPKC provided larger operable working angles for the targets. The angles by MPKC, particularly for the MCAB, reached up to 1.9-fold of those by SOKC. Greater working depths were required in order to reach the targets by SOKC, and the differences were the greatest in the MCAB by 1.6-fold. MPKC provides larger exposure than SOKC with a similar length of skin incision. MPKC allows for use of a direct transsylvian approach, and exposes the target in a wide working angle within a short distance. Despite some limitations in exposure, SOKC is suitable for a direct subfrontal approach, and provides a more anteromedial and basal view. MCAB and posteriorly directing ICA terminal aneurysms can be good candidates for MPKC.

Solar and lunar tidal variabilities in GPS-TEC and geomagnetic field variations: Seasonal as well as during the sudden stratospheric warming of 2010

NASA Astrophysics Data System (ADS)

Sridharan, S.

2017-04-01

The Global Positioning System (GPS) deduced total electron content (TEC) data at 15°N (geomagnetic), which is the northern crest region of equatorial ionization anomaly, are used to study solar and lunar tidal variabilities during the years 2008 and 2009 and also during the 2009-2010 winter, when a major sudden stratospheric warming (SSW) event has occurred. The diurnal and semidiurnal tidal amplitudes show semiannual variation with maximum amplitudes during February-March and September-November, whereas terdiurnal tide is larger during April-September. They show significant longitudinal variability with larger (smaller) amplitudes over 250°E-150°E (200°E-250°E). Lunar semidiurnal tidal amplitudes show sporadic enhancements during northern winter months and negligible amplitudes during northern summer months. They also show notable longitudinal variabilities. The solar migrating tides DW1 and SW2 show semiannual variation with larger amplitudes during spring equinox months, whereas TW3 maximizes during northern summer. DW2 shows larger amplitudes during summer months. During the SSW, except TW3, the migrating tides DW1 and SW2 show considerable enhancements. Among solar nonmigrating tides, SW1, TW2, and DS0 show larger enhancements. Solar tides in TEC and equatorial electrojet strength over Tirunelveli vary with the time scale of 60 days during October 2009-March 2010 similar to ozone mass mixing ratio at 10 hPa, and this confirms the vital role of ozone in tidal variabilities in ionospheric parameters. Lunar tidal amplitudes in changes in horizontal component of geomagnetic field (ΔH) are larger over Tirunelveli, a station near dip equator. Solar semidiurnal tides in ΔH have larger amplitudes than lunar tides over polar stations, Mawson and Godhavn.