Comparison of torsional and microburst longitudinal phacoemulsification: a prospective, randomized, masked clinical trial.

PubMed

Vasavada, Abhay R; Raj, Shetal M; Patel, Udayan; Vasavada, Vaishali; Vasavada, Viraj

2010-01-01

To compare intraoperative performance and postoperative outcome of three phacoemulsification technologies in patients undergoing microcoaxial phacoemulsification through 2.2-mm corneal incisions. The prospective, randomized, single-masked study included 360 eyes randomly assigned to torsional (Infiniti Vision System; Alcon Laboratories, Fort Worth, TX), microburst with longitudinal (Infiniti), or microburst with longitudinal (Legacy Everest, Alcon Laboratories) ultrasound. Assessments included surgical clock time, fluid volume, and intraoperative complications, central corneal thickness on day 1 and months 1 and 3 postoperatively, and endothelial cell density at 3 months postoperatively. Comparisons among groups were conducted. Torsional ultrasound required significantly less surgical clock time and fluid volume than the other groups. There were no intraoperative complications. Change in central corneal thickness and endothelial cell loss was significantly lower in the torsional ultrasound group at all postoperative visits (P < .001, Kruskal-Wallis test) compared to microburst longitudinal ultrasound modalities. Torsional ultrasound demonstrated quantitatively superior intraoperative performance and showed less increase in corneal thickness and less endothelial cell loss compared to microburst longitudinal ultrasound. Copyright 2010, SLACK Incorporated.

Differences in Causal Estimates from Longitudinal Analyses of Residualized versus Simple Gain Scores: Contrasting Controls for Selection and Regression Artifacts

ERIC Educational Resources Information Center

Larzelere, Robert E.; Ferrer, Emilio; Kuhn, Brett R.; Danelia, Ketevan

2010-01-01

This study estimates the causal effects of six corrective actions for children's problem behaviors, comparing four types of longitudinal analyses that correct for pre-existing differences in a cohort of 1,464 4- and 5-year-olds from Canadian National Longitudinal Survey of Children and Youth (NLSCY) data. Analyses of residualized gain scores found…

Social and Behavioural Outcomes in Children Diagnosed with Autism Spectrum Disorders: A Longitudinal Cohort Study

ERIC Educational Resources Information Center

Russell, Ginny; Golding, Jean; Norwich, Brahm; Emond, Alan; Ford, Tamsin; Steer, Colin

2012-01-01

Objective: To compare social and behavioural outcomes between children formally diagnosed with autism spectrum disorders (ASD) with those of children who displayed autistic traits at preschool age, but remained undiagnosed as teenagers. Method: A secondary analysis of data from a birth cohort study, the Avon Longitudinal Study of Parents and…

A Longitudinal Study of Idiom and Text Comprehension

ERIC Educational Resources Information Center

Levorato, M. Chiara; Roch, Maja; Nesi, Barbara

2007-01-01

The relation between text and idiom comprehension in children with poor text comprehension skills was investigated longitudinally. In the first phase of the study, six-year-old first graders with different levels of text comprehension were compared in an idiom and sentence comprehension task. Text comprehension was shown to be more closely related…

A Longitudinal Study of ESL Learners' Fluency and Comprehensibility Development

ERIC Educational Resources Information Center

Derwing, Tracey M.; Munro, Murray J.; Thomson, Ron I.

2008-01-01

This longitudinal mixed-methods study compared the oral fluency of well-educated adult immigrants from Mandarin and Slavic language backgrounds (16 per group) enrolled in introductory English as a second language (ESL) classes. Speech samples were collected over a 2-year period, together with estimates of weekly English use. We also conducted…

Classroom Connectivity and Algebra 1 Achievement: A Three-Year Longitudinal Study

ERIC Educational Resources Information Center

Irving, Karen E.; Pape, Stephen J.; Owens, Douglas T.; Abrahamson, Louis; Silver, David; Sanalan, Vehbi A.

2016-01-01

Findings from three years of a longitudinal randomized control trial involving a national U.S. sample of Algebra 1 teachers and students are reported. The study examines the effects of a connected classroom technology (CCT) professional development and classroom intervention on student achievement when compared to classroom instruction with…

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

ERIC Educational Resources Information Center

Vander Schee, Brian A.

2009-01-01

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

Comparison of CTT and Rasch-based approaches for the analysis of longitudinal Patient Reported Outcomes.

PubMed

Blanchin, Myriam; Hardouin, Jean-Benoit; Le Neel, Tanguy; Kubis, Gildas; Blanchard, Claire; Mirallié, Eric; Sébille, Véronique

2011-04-15

Health sciences frequently deal with Patient Reported Outcomes (PRO) data for the evaluation of concepts, in particular health-related quality of life, which cannot be directly measured and are often called latent variables. Two approaches are commonly used for the analysis of such data: Classical Test Theory (CTT) and Item Response Theory (IRT). Longitudinal data are often collected to analyze the evolution of an outcome over time. The most adequate strategy to analyze longitudinal latent variables, which can be either based on CTT or IRT models, remains to be identified. This strategy must take into account the latent characteristic of what PROs are intended to measure as well as the specificity of longitudinal designs. A simple and widely used IRT model is the Rasch model. The purpose of our study was to compare CTT and Rasch-based approaches to analyze longitudinal PRO data regarding type I error, power, and time effect estimation bias. Four methods were compared: the Score and Mixed models (SM) method based on the CTT approach, the Rasch and Mixed models (RM), the Plausible Values (PV), and the Longitudinal Rasch model (LRM) methods all based on the Rasch model. All methods have shown comparable results in terms of type I error, all close to 5 per cent. LRM and SM methods presented comparable power and unbiased time effect estimations, whereas RM and PV methods showed low power and biased time effect estimations. This suggests that RM and PV methods should be avoided to analyze longitudinal latent variables. Copyright © 2010 John Wiley & Sons, Ltd.

Transverse versus Longitudinal Incisions for Femoral Artery Exposure in Treating Patients with Peripheral Vascular Disease.

PubMed

Parikh, Punam P; Rubio, Gustavo A; Patel, Kunal; Gupta, Kapil; Jones, Keith; Rey, Jorge; Robinson, Handel

2018-02-01

This study evaluates differences in wound complication rate when transverse versus longitudinal incision is utilized to expose femoral vessels in managing patients with peripheral vascular disease. A retrospective review from 2013 to 2015 was conducted of 150 patients undergoing 156 lower extremity revascularizations with femoral artery exposure through a groin incision. Patients were stratified into 2 groups, transverse versus longitudinal groin incision. Data were reviewed for 3 surgeons that utilize either transverse or longitudinal groin incision in patients undergoing common or iliofemoral endarterectomies, or where femoral artery was used as inflow and/or outflow vessel for limb revascularization. Each group had a comparative outcomes analysis based on incision type. The primary outcome was wound complication, defined as any wound infection, lymphocele, hematoma, dehiscence, pseudoaneurysm, or necrosis. Other outcomes studied included unplanned return to operating room for wound complication, wound vacuum therapy, and soft-tissue flap closure. Data were analyzed using 2-tailed chi-squared test and Student's t-test. Patients in the transverse (n = 85 cases) versus longitudinal (n = 71 cases) cohorts were similar in relation to demographics and comorbidities. Overall mean follow-up was 220 days. Patients with a transverse as compared to longitudinal incision had a significantly lower overall wound complication rate, 7% vs. 42%, respectively (P < 0.001). Furthermore, transverse incisions were associated with lower incidence of unplanned return to the operating room to manage wound complications than patients with a longitudinal incision (5% vs. 23%, respectively; P < 0.001). Transverse versus longitudinal incisions were also associated with significantly lower need for wound vacuum therapy (6% vs. 15%, respectively; P < 0.05) and muscle flap closure (0% vs. 13%, respectively; P < 0.001) for wound complications. Transverse groin incisions for femoral artery exposure may offer a lower risk of wound complications for open procedures as compared to a longitudinal incision. While longitudinal incisions may have higher wound complication rates, incisional approach is contingent on anatomical circumstance and treated disease pattern. Patients should undergo appropriate preoperative counseling regarding wound healing in preparation for limb revascularization. Copyright © 2017 Elsevier Inc. All rights reserved.

Where Is the Engineering I Applied For? A Longitudinal Study of Students' Transition into Higher Education Engineering, and Their Considerations of Staying or Leaving

ERIC Educational Resources Information Center

Holmegaard, Henriette Tolstrup; Madsen, Lene Møller; Ulriksen, Lars

2016-01-01

This paper presents results from a qualitative longitudinal study of students' transition into higher education engineering. The study aims at comparing upper-secondary school students' expectations of engineering with their actual experiences when encountering the engineering programme. It explores how this encounter provides a platform for…

Second- to third-trimester longitudinal growth assessment for prediction of small-for-gestational age and late fetal growth restriction.

PubMed

Caradeux, J; Eixarch, E; Mazarico, E; Basuki, T R; Gratacós, E; Figueras, F

2018-02-01

Detection of fetal growth restriction (FGR) remains poor and most screening strategies rely on cross-sectional evaluation of fetal size during the third trimester. A longitudinal and individualized approach has been proposed as an alternative method of evaluation. The aim of this study was to compare second- to third-trimester longitudinal growth assessment to cross-sectional evaluation in the third trimester for the prediction of small-for-gestational age (SGA) and late FGR in low-risk singleton pregnancy. This was a prospective cohort study of 2696 unselected consecutive low-risk singleton pregnancies scanned at 21 ± 2 and 32 ± 2 weeks. For cross-sectional growth assessment, abdominal circumference (AC) measurements were transformed to z-values according the 21st-INTERGROWTH standards. Longitudinal growth assessment was performed by calculating the AC z-velocity and the second- to third-trimester AC conditional growth centile. Longitudinal assessment was compared with cross-sectional assessment at 32 weeks. Association of cross-sectional and longitudinal evaluations with SGA and late FGR was assessed by logistic regression analysis. Predictive performance was determined by receiver-operating characteristics curve analysis. In total, 210 (7.8%) newborns were classified as SGA and 103 (3.8%) as late FGR. Neither longitudinal measurement improved the association with SGA or late FGR provided by cross-sectional evaluation of AC z-score at 32 weeks. Areas under the curves of AC z-velocity and conditional AC growth were significantly smaller than those of cross-sectional AC z-scores (P < 0.001), although AC z-velocity performed significantly better than did conditional AC growth (P < 0.001). Longitudinal assessment of fetal growth from the second to third trimester has a low predictive capacity for SGA and late FGR in low-risk singleton pregnancy compared with cross-sectional growth evaluation. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

A Longitudinal Investigation of Reading Development from Kindergarten to Grade Eight in a Spanish-Speaking Bilingual Population

ERIC Educational Resources Information Center

Grimm, Ryan P.; Solari, Emily J.; Gerber, Michael M.

2018-01-01

This longitudinal study used latent growth curve modeling to investigate English literacy development in a sample of Spanish-speaking language minority students from third through eighth grade. This study also compared the sample's literacy development to the entire population of California students using state standardized test data. Second, this…

Emotional Intelligence throughout Portuguese Secondary School: A Longitudinal Study Comparing Performance and Self-Report Measures

ERIC Educational Resources Information Center

Costa, Ana; Faria, Luísa

2016-01-01

This study examines the developmental trajectories of ability and trait emotional intelligence (EI) in the Portuguese secondary school. Within a three-wave longitudinal design, 395 students (M[subscript age] = 15.4; SD = 0.74) completed both the Emotional Skills and Competence Questionnaire (ESCQ) and the Vocabulary of Emotions Test (VET). Results…

Longitudinal Investigation of Perceptions towards University Concept through Metaphors: A University Sample in Turkey

ERIC Educational Resources Information Center

Argon, Türkan

2015-01-01

This study aims to fill the gap in the field of observation-based longitudinal studies about metaphors in educational literature and investigates students' perceptions about the concept of university before and after university by identifying and comparing the change and the direction of change observed in perceptions. The phenomenological study…

Some Audiological, Psychological, Educational and Behavioral Characteristics of Children with Bilateral Otitis Media with Effusion: A Longitudinal Study.

ERIC Educational Resources Information Center

Silva, Phil A.; And Others

1986-01-01

A longitudinal study of 47 children with bilateral otitis media with effusion (OME) at age five compared with a group of non-OME children revealed that OME Ss continued to have significant hearing loss at subsequent ages, as well as language, speech, behavior, and reading difficulties. (Author/CL)

Longitudinal Changes in Adaptive Behavior in Adults with Down Syndrome: Interim Findings from a Longitudinal Study.

ERIC Educational Resources Information Center

Prasher, V. P.; Chung, Man Cheung; Haque, M. S.

1998-01-01

A study examined underlying factors for age-related decline in adaptive behavior in 128 adults with trisomy 21 over a three-year period. Presence of dementia was the only determining factor, although the difference in trend over time as compared to subjects without dementia was not significant. (Author/CR)

Head Start Participation and School Readiness: Evidence from the Early Childhood Longitudinal Study-Birth Cohort

ERIC Educational Resources Information Center

Lee, RaeHyuck; Zhai, Fuhua; Brooks-Gunn, Jeanne; Han, Wen-Jui; Waldfogel, Jane

2014-01-01

Using data from the Early Childhood Longitudinal Study-Birth Cohort (n ˜ 6,950), a nationally representative sample of children born in 2001, we examined school readiness (academic skills and socioemotional well-being) at kindergarten entry for children who attended Head Start compared with those who experienced other types of child care…

Enhanced Development of Auditory Change Detection in Musically Trained School-Aged Children: A Longitudinal Event-Related Potential Study

ERIC Educational Resources Information Center

Putkinen, Vesa; Tervaniemi, Mari; Saarikivi, Katri; Ojala, Pauliina; Huotilainen, Minna

2014-01-01

Adult musicians show superior auditory discrimination skills when compared to non-musicians. The enhanced auditory skills of musicians are reflected in the augmented amplitudes of their auditory event-related potential (ERP) responses. In the current study, we investigated longitudinally the development of auditory discrimination skills in…

Right Ventricular Longitudinal Strain Is Depressed in a Bovine Model of Pulmonary Hypertension.

PubMed

Bartels, Karsten; Brown, R Dale; Fox, Daniel L; Bull, Todd M; Neary, Joseph M; Dorosz, Jennifer L; Fonseca, Brian M; Stenmark, Kurt R

2016-05-01

Pulmonary hypertension and resulting right ventricular (RV) dysfunction are associated with significant perioperative morbidity and mortality. Although echocardiography permits real-time, noninvasive assessment of RV function, objective and comparative measures are underdeveloped, and appropriate animal models to study their utility are lacking. Longitudinal strain analysis is a novel echocardiographic method to quantify RV performance. Herein, we hypothesized that peak RV longitudinal strain would worsen in a bovine model of pulmonary hypertension compared with control animals. Newborn Holstein calves were randomly chosen for induction of pulmonary hypertension versus control conditions. Pulmonary hypertension was induced by exposing animals to 14 days of hypoxia (equivalent to 4570 m above sea level or 430 mm Hg barometric pressure). Control animals were kept at ambient pressure/normoxia. At the end of the intervention, transthoracic echocardiography was performed in awake calves. Longitudinal wall strain was analyzed from modified apical 4-chamber views focused on the RV. Comparisons between measurements in hypoxic versus nonhypoxic conditions were performed using Student t test for independent samples and unequal variances. After 14 days at normoxic versus hypoxic conditions, 15 calves were examined with echocardiography. Pulmonary hypertension was confirmed by right heart catheterization and associated with reduced RV systolic function. Mean systolic strain measurements were compared in normoxia-exposed animals (n = 8) and hypoxia-exposed animals (n = 7). Peak global systolic longitudinal RV strain after hypoxia worsened compared to normoxia (-10.5% vs -16.1%, P = 0.0031). Peak RV free wall strain also worsened after hypoxia compared to normoxia (-9.6% vs -17.3%, P = 0.0031). Findings from strain analysis were confirmed by measurement of tricuspid annular peak systolic excursion. Peak longitudinal RV strain detected worsened RV function in animals with hypoxia-induced pulmonary hypertension compared with control animals. This relationship was demonstrated in the transthoracic echocardiographic 4-chamber view independently for the RV free wall and for the combination of the free and septal walls. This innovative model of bovine pulmonary hypertension may prove useful to compare different monitoring technologies for the assessment of early events of RV dysfunction. Further studies linking novel RV imaging applications with mechanistic and therapeutic approaches are needed.

Investigation of 2‐stage meta‐analysis methods for joint longitudinal and time‐to‐event data through simulation and real data application

PubMed Central

Tudur Smith, Catrin; Gueyffier, François; Kolamunnage‐Dona, Ruwanthi

2017-01-01

Background Joint modelling of longitudinal and time‐to‐event data is often preferred over separate longitudinal or time‐to‐event analyses as it can account for study dropout, error in longitudinally measured covariates, and correlation between longitudinal and time‐to‐event outcomes. The joint modelling literature focuses mainly on the analysis of single studies with no methods currently available for the meta‐analysis of joint model estimates from multiple studies. Methods We propose a 2‐stage method for meta‐analysis of joint model estimates. These methods are applied to the INDANA dataset to combine joint model estimates of systolic blood pressure with time to death, time to myocardial infarction, and time to stroke. Results are compared to meta‐analyses of separate longitudinal or time‐to‐event models. A simulation study is conducted to contrast separate versus joint analyses over a range of scenarios. Results Using the real dataset, similar results were obtained by using the separate and joint analyses. However, the simulation study indicated a benefit of use of joint rather than separate methods in a meta‐analytic setting where association exists between the longitudinal and time‐to‐event outcomes. Conclusions Where evidence of association between longitudinal and time‐to‐event outcomes exists, results from joint models over standalone analyses should be pooled in 2‐stage meta‐analyses. PMID:29250814

[Comparative study of N, P output and eutrophication risk in runoff water in cross ridge and longitudinal ridge].

PubMed

Yu, Xing-Xiu; Ma, Qian; Liu, Qian-Jin; Lü, Guo-An

2011-02-01

Field in-situ rainfall simulation tests with two rainfall intensities (40 mm x h(-1) and 70 mm x h(-1)), which were conducted at typical sloping cropland in Yimeng mountainous area, were designed to analyze the output characteristics of dissolved inorganic nitrogen, Inorganic-N (NO3(-)-N, NH4(+) -N) and dissolved phosphorus (DP) in runoff water, as well as to compare the eutrophication risk in this water by calculating three ratios of Inorganic-N/DP, NO3(-) -N/DP, and NH4(+)-N/DP, respectively, in cross ridge and longitudinal ridge tillage methods. Results showed that, under the same rainfall intensity, the DP level in runoff water was higher in cross ridge than longitudinal ridge, while the change of different Inorganic-N level between the two tillage methods were not consistent. Cross ridge could effectively reduce runoff and the output rate of Inorganic-N and DP when compared to the longitudinal ridge tillage, which would be more outstanding with the increases of rainfall intensities. The losses of Inorganic-N and DP in runoff water were 43% and 5% less, respectively, in cross ridge than longitudinal ridge at the 40 mm x h(-1) rainfall intensity, and were 68% and 55%, respectively, at 70 mm x h(-1). The higher Inorganic-N/DP and NO3(-) -N/DP ratios suggest that runoff water from either cross ridge or longitudinal ridge tillage have a certain eutrophication risk, which present an increasing trend during the precipitation-runoff process. Compared with longitudinal ridge, cross ridge can not only hinder the increasing trend of eutrophication risk, but also can significantly lower it, and thus effectively reduce the effect of sloping cropland runoff on the eutrophication processes of receiving waters.

A Longitudinal Study of Individual and Organisational Learning

ERIC Educational Resources Information Center

Campbell, Timothy T.; Armstrong, Steven J.

2013-01-01

Purpose: The purpose of this paper is to empirically examine organisational learning (OL) and individual managerial learning and provide a comparative evaluation of the ability of each to generate organisational benefits. Design/methodology/approach: A theoretical model of organisational learning is developed which was then longitudinally tested…

Projected impact of the ICD-10-CM/PCS conversion on longitudinal data and the Joint Commission Core Measures.

PubMed

Fenton, Susan H; Benigni, Mary Sue

2014-01-01

The transition from ICD-9-CM to ICD-10-CM/PCS is expected to result in longitudinal data discontinuities, as occurred with cause-of-death in 1999. The General Equivalence Maps (GEMs), while useful for suggesting potential maps do not provide guidance regarding the frequency of any matches. Longitudinal data comparisons can only be reliable if they use comparability ratios or factors which have been calculated using records coded in both classification systems. This study utilized 3,969 de-identified dually coded records to examine raw comparability ratios, as well as the comparability ratios between the Joint Commission Core Measures. The raw comparability factor results range from 16.216 for Nicotine dependence, unspecified, uncomplicated to 118.009 for Chronic obstructive pulmonary disease, unspecified. The Joint Commission Core Measure comparability factor results range from 27.15 for Acute Respiratory Failure to 130.16 for Acute Myocardial Infarction. These results indicate significant differences in comparability between ICD-9-CM and ICD-10-CM code assignment, including when the codes are used for external reporting such as the Joint Commission Core Measures. To prevent errors in decision-making and reporting, all stakeholders relying on longitudinal data for measure reporting and other purposes should investigate the impact of the conversion on their data.

Advanced analytical methodologies for measuring healthy ageing and its determinants, using factor analysis and machine learning techniques: the ATHLOS project

PubMed Central

Félix Caballero, Francisco; Soulis, George; Engchuan, Worrawat; Sánchez-Niubó, Albert; Arndt, Holger; Ayuso-Mateos, José Luis; Haro, Josep Maria; Chatterji, Somnath; Panagiotakos, Demosthenes B.

2017-01-01

A most challenging task for scientists that are involved in the study of ageing is the development of a measure to quantify health status across populations and over time. In the present study, a Bayesian multilevel Item Response Theory approach is used to create a health score that can be compared across different waves in a longitudinal study, using anchor items and items that vary across waves. The same approach can be applied to compare health scores across different longitudinal studies, using items that vary across studies. Data from the English Longitudinal Study of Ageing (ELSA) are employed. Mixed-effects multilevel regression and Machine Learning methods were used to identify relationships between socio-demographics and the health score created. The metric of health was created for 17,886 subjects (54.6% of women) participating in at least one of the first six ELSA waves and correlated well with already known conditions that affect health. Future efforts will implement this approach in a harmonised data set comprising several longitudinal studies of ageing. This will enable valid comparisons between clinical and community dwelling populations and help to generate norms that could be useful in day-to-day clinical practice. PMID:28281663

Advanced analytical methodologies for measuring healthy ageing and its determinants, using factor analysis and machine learning techniques: the ATHLOS project.

PubMed

Caballero, Francisco Félix; Soulis, George; Engchuan, Worrawat; Sánchez-Niubó, Albert; Arndt, Holger; Ayuso-Mateos, José Luis; Haro, Josep Maria; Chatterji, Somnath; Panagiotakos, Demosthenes B

2017-03-10

A most challenging task for scientists that are involved in the study of ageing is the development of a measure to quantify health status across populations and over time. In the present study, a Bayesian multilevel Item Response Theory approach is used to create a health score that can be compared across different waves in a longitudinal study, using anchor items and items that vary across waves. The same approach can be applied to compare health scores across different longitudinal studies, using items that vary across studies. Data from the English Longitudinal Study of Ageing (ELSA) are employed. Mixed-effects multilevel regression and Machine Learning methods were used to identify relationships between socio-demographics and the health score created. The metric of health was created for 17,886 subjects (54.6% of women) participating in at least one of the first six ELSA waves and correlated well with already known conditions that affect health. Future efforts will implement this approach in a harmonised data set comprising several longitudinal studies of ageing. This will enable valid comparisons between clinical and community dwelling populations and help to generate norms that could be useful in day-to-day clinical practice.

The Influence of Stimulus Material on Attention and Performance in the Visual Expectation Paradigm: A Longitudinal Study with 3- And 6-Month-Old Infants

ERIC Educational Resources Information Center

Teubert, Manuel; Lohaus, Arnold; Fassbender, Ina; Vierhaus, Marc; Spangler, Sibylle; Borchert, Sonja; Freitag, Claudia; Goertz, Claudia; Graf, Frauke; Gudi, Helene; Kolling, Thorsten; Lamm, Bettina; Keller, Heidi; Knopf, Monika; Schwarzer, Gudrun

2012-01-01

This longitudinal study examined the influence of stimulus material on attention and expectation learning in the visual expectation paradigm. Female faces were used as attention-attracting stimuli, and non-meaningful visual stimuli of comparable complexity (Greebles) were used as low attention-attracting stimuli. Expectation learning performance…

Changes in Weight over the School Year and Summer Vacation: Results of a 5-Year Longitudinal Study

ERIC Educational Resources Information Center

Moreno, Jennette P.; Johnston, Craig A.; Woehler, Deborah

2013-01-01

Background: Evidence suggests that children gain more weight during the summer months compared with the school year. To examine the impact of the school and summer environment on children's weight further, we conducted a 5-year longitudinal study examining changes in standardized BMI (zBMI) of students entering kindergarten. Methods: Heights and…

Effects of an Incentive Based Budgeting System on Institutional Performance Indicators: An Exploratory Longitudinal Case Study of a Public University

ERIC Educational Resources Information Center

Willett, Michael S.

2013-01-01

The purpose of this exploratory longitudinal case study was to examine how the implementation of an Incentive Based Budgeting (IBB) system (i.e., Responsibility-Centered Management [RCM]) affected selected institutional performance indicators at the campus level and two comparable schools at a large Mid-Western public University. The value of…

Oral Language and Narrative Skills in Children with Specific Language Impairment with and without Literacy Delay: A Three-Year Longitudinal Study

ERIC Educational Resources Information Center

Vandewalle, Ellen; Boets, Bart; Boons, Tinne; Ghesquiere, Pol; Zink, Inge

2012-01-01

This longitudinal study compared the development of oral language and more specifically narrative skills (storytelling and story retelling) in children with specific language impairment (SLI) with and without literacy delay. Therefore, 18 children with SLI and 18 matched controls with normal literacy were followed from the last year of…

Bridging the Gap: A Longitudinal Study of the Relationship between Pedagogical Continuity and Early Chinese Literacy Acquisition

ERIC Educational Resources Information Center

Li, Hui; Rao, Nirmala; Tse, Shek Kam

2011-01-01

This longitudinal study examined the relationship between pedagogical continuity in literacy education and early literacy development by comparing Chinese children in Hong Kong and Shenzhen. Stratified random sampling was used to select 24 preschool and Primary 1 classes in four communities catering to middle-class families in each city. The 24…

Telomere length dynamics differ in foetal and early post-natal human leukocytes in a longitudinal study.

PubMed

Holmes, Denise K; Bellantuono, Ilaria; Walkinshaw, Steve A; Alfirevic, Zarko; Johnston, Tracey A; Subhedar, Nimish V; Chittick, Rachel; Swindell, Richard; Wynn, Robert F

2009-06-01

Haemopoietic stem cells (HSC) undergo a process of self renewal to constantly maintain blood cell turnover. However, it has become apparent that adult HSC lose their self-renewal ability with age. Telomere shortening in peripheral blood leukocytes has been seen to occur with age and it has been associated with loss of HSC proliferative capacity and cellular ageing. In contrast foetal HSC are known to have greater proliferative capacity than post-natal stem cells. However it is unknown whether they undergo a similar process of telomere shortening. In this study we show a more accentuated rate of telomere loss in leukocytes from pre term infants compared to human foetuses of comparable age followed longitudinally for 8-12 weeks in a longitudinal study. Our results point to a difference in HSC behaviour between foetal and early postnatal life which is independent of age but may be influenced by events at birth itself.

An air brake model for longitudinal train dynamics studies

NASA Astrophysics Data System (ADS)

Wei, Wei; Hu, Yang; Wu, Qing; Zhao, Xubao; Zhang, Jun; Zhang, Yuan

2017-04-01

Experience of heavy haul train operation shows that heavy haul train fatigue fracture of coupler and its related components, even the accidents are caused by excessive coupler force. The most economical and effective method to study on train longitudinal impulse by reducing the coupler force is simulation method. The characteristics of train air brake system is an important excitation source for the study of longitudinal impulse. It is very difficult to obtain the braking characteristic by the test method, a better way to get the input parameters of the excitation source in the train longitudinal dynamics is modelling the train air brake system. In this paper, the air brake system model of integrated system of air brake and longitudinal dynamics is introduced. This introduce is focus on the locomotive automatic brake valve and vehicle distribution valve model, and the comparative analysis of the simulation and test results of the braking system is given. It is proved that the model can predict the characteristics of train braking system. This method provides a good solution for the excitation source of longitudinal dynamic analysis system.

Longitudinal Examination of Adaptive Behavior in Autism Spectrum Disorders: Influence of Executive Function

ERIC Educational Resources Information Center

Pugliese, Cara E.; Anthony, Laura Gutermuth; Strang, John F.; Dudley, Katerina; Wallace, Gregory L.; Naiman, Daniel Q.; Kenworthy, Lauren

2016-01-01

This study characterizes longitudinal change in adaptive behavior in 64 children and adolescents with autism spectrum disorder (ASD) without intellectual disability evaluated on multiple occasions, and examines whether prior estimate of executive function (EF) problems predicts future adaptive behavior scores. Compared to standardized estimates…

Using Hand Grip Force as a Correlate of Longitudinal Acceleration Comfort for Rapid Transit Trains

PubMed Central

Guo, Beiyuan; Gan, Weide; Fang, Weining

2015-01-01

Longitudinal acceleration comfort is one of the essential metrics used to evaluate the ride comfort of train. The aim of this study was to investigate the effectiveness of using hand grip force as a correlate of longitudinal acceleration comfort of rapid transit trains. In the paper, a motion simulation system was set up and a two-stage experiment was designed to investigate the role of the grip force on the longitudinal comfort of rapid transit trains. The results of the experiment show that the incremental grip force was linearly correlated with the longitudinal acceleration value, while the incremental grip force had no correlation with the direction of the longitudinal acceleration vector. The results also show that the effects of incremental grip force and acceleration duration on the longitudinal comfort of rapid transit trains were significant. Based on multiple regression analysis, a step function model was established to predict the longitudinal comfort of rapid transit trains using the incremental grip force and the acceleration duration. The feasibility and practicably of the model was verified by a field test. Furthermore, a comparative analysis shows that the motion simulation system and the grip force based model were valid to support the laboratory studies on the longitudinal comfort of rapid transit trains. PMID:26147730

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

PubMed

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

2017-08-15

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

Investigation of 2-stage meta-analysis methods for joint longitudinal and time-to-event data through simulation and real data application.

PubMed

Sudell, Maria; Tudur Smith, Catrin; Gueyffier, François; Kolamunnage-Dona, Ruwanthi

2018-04-15

Joint modelling of longitudinal and time-to-event data is often preferred over separate longitudinal or time-to-event analyses as it can account for study dropout, error in longitudinally measured covariates, and correlation between longitudinal and time-to-event outcomes. The joint modelling literature focuses mainly on the analysis of single studies with no methods currently available for the meta-analysis of joint model estimates from multiple studies. We propose a 2-stage method for meta-analysis of joint model estimates. These methods are applied to the INDANA dataset to combine joint model estimates of systolic blood pressure with time to death, time to myocardial infarction, and time to stroke. Results are compared to meta-analyses of separate longitudinal or time-to-event models. A simulation study is conducted to contrast separate versus joint analyses over a range of scenarios. Using the real dataset, similar results were obtained by using the separate and joint analyses. However, the simulation study indicated a benefit of use of joint rather than separate methods in a meta-analytic setting where association exists between the longitudinal and time-to-event outcomes. Where evidence of association between longitudinal and time-to-event outcomes exists, results from joint models over standalone analyses should be pooled in 2-stage meta-analyses. © 2017 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

Cross-sectional and longitudinal epidemiological studies of Internet gaming disorder: A systematic review of the literature.

PubMed

Mihara, Satoko; Higuchi, Susumu

2017-07-01

The diagnostic criteria of Internet gaming disorder (IGD) have been included in section III of DSM-5. This study aims to systematically review both cross-sectional and longitudinal epidemiological studies of IGD. All publications included in PubMed and PsychINFO up to May 2016 were systematically searched to identify cross-sectional studies on prevalence and longitudinal studies of IGD. In the process of identification, articles in non-English languages and studies focusing solely on the use of gaming were excluded, and those meeting the methodological requirements set by this review were included. As a result, 37 cross-sectional and 13 longitudinal studies were selected for review. The prevalence of IGD in the total samples ranged from 0.7% to 27.5%. The prevalence was higher among males than females in the vast majority of studies and tended to be higher among younger rather than older people in some studies. Geographical region made little difference to prevalence. Factors associated with IGD were reported in 28 of 37 cross-sectional studies. These were diverse and covered gaming, demographic and familial factors, interpersonal relations, social and school functioning, personality, psychiatric comorbidity, and physical health conditions. Longitudinal studies identified risk and protective factors, and health and social consequences of IGD. The natural course of IGD was diverse but tended to be more stable among adolescents compared to adults. Although existing epidemiological studies have provided useful data, differences in methodologies make it difficult to compare the findings of these studies when drawing consensus. Future international studies using reliable and uniform methods are warranted. © 2017 The Authors. Psychiatry and Clinical Neurosciences © 2017 Japanese Society of Psychiatry and Neurology.

Accounting for dropout reason in longitudinal studies with nonignorable dropout.

PubMed

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

2017-08-01

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

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

PubMed

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

2016-04-28

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

LONGITUDINAL TRAJECTORIES OF ARTERIAL STIFFNESS AND THE ROLE OF BLOOD PRESSURE: THE BALTIMORE LONGITUDINAL STUDY OF AGING

PubMed Central

AlGhatrif, Majd; Strait, James B.; Morrell, Chris; Canepa, Marco; Wright, Jeanette; Elango, Palchamy; Scuteri, Angelo; Najjar, Samer S.; Ferrucci, Luigi; Lakatta, Edward G.

2013-01-01

Carotid-femoral pulse wave velocity (PWV), a marker of arterial stiffness, is an established independent cardiovascular (CV) risk factor. Little information is available on the pattern and determinants of the longitudinal change in PWV with aging. Such information is crucial to elucidating mechanisms underlying arterial stiffness and the design of interventions to retard it. Between 1988 and 2013, we collected 2 to 9 serial measures of PWV in 354 men and 423 women of the Baltimore Longitudinal Study of Aging, who were 21 to 94 years of age and free of clinically significant CV disease. Rates of PWV increase accelerated with advancing age in men more than women, leading to gender differences in PWV after the age of 50. In both sexes, not only systolic blood pressure (SBP) ≥140mmHg, but also SBP of 120–139mmHg was associated with steeper rates of PWV increase compared to SBP<120mmHg. Furthermore, there was a dose-dependent effect SBP in men with marked acceleration in PWV rate of increase with age at SBP ≥140mmHg compared to SBP of 120–139mmHg. Except for waist circumference in women, no other traditional CV risk factors predicted longitudinal PWV increase. In conclusion, the steeper longitudinal increase of PWV in men than women led to gender difference that expanded with advancing age. Age and systolic blood pressure are the main longitudinal determinants of pulse wave velocity and the effect of systolic blood pressure on PWV trajectories exists even in the pre-hypertensive range. PMID:24001897

Development of Phonological Processing Skills in Children with Specific Language Impairment with and without Literacy Delay: A 3-Year Longitudinal Study

ERIC Educational Resources Information Center

Vandewalle, Ellen; Boets, Bart; Ghesquiere, Pol; Zink, Inge

2012-01-01

Purpose: To compare the development of phonological skills in children with specific language impairment (SLI) with and without literacy delay and to examine whether kindergarten phonological skills could discriminate these 2 groups. Method: In a longitudinal study, 8 children with SLI and literacy delay, 10 children with SLI and normal literacy,…

Socioeconomic gradients of cardiovascular risk factors in China and India: results from the China health and retirement longitudinal study and longitudinal aging study in India.

PubMed

Hu, Peifeng; Wang, Serena; Lee, Jinkook

2017-09-01

Cardiovascular disease has become a major public health challenge in developing countries. The goal of this study is to compare socioeconomic status (SES) gradients of cardiovascular risk factors (CVRF) both within and between China and India. We used multivariable logistic regression models to examine the associations between SES and CVRF, using data from the China health and retirement longitudinal study and the longitudinal aging study in India. The results showed that, compared to illiteracy, the odds ratios of completing junior high school for high-risk waist circumference were 4.99 (95% confidence interval: 1.77-14.06) among Indian men, 3.42 (95% confidence interval: 1.66-7.05) among Indian women, but 0.74 (95% confidence interval: 0.59-0.92) among Chinese women. Similar patterns were observed between educational attainment and high-risk body mass index, and between education and hypertension, based on self-reported physician diagnosis and direct blood pressure measurements. SES is associated with CVRF in both China and India. However, this relationship showed opposite patterns across two countries, suggesting that this association is not fixed, but is subjective to underlying causal pathways, such as patterns of risky health behaviors and different social and health policies.

A Longitudinal Study on Resting State Functional Connectivity in Behavioral Variant Frontotemporal Dementia and Alzheimer's Disease.

PubMed

Hafkemeijer, Anne; Möller, Christiane; Dopper, Elise G P; Jiskoot, Lize C; van den Berg-Huysmans, Annette A; van Swieten, John C; van der Flier, Wiesje M; Vrenken, Hugo; Pijnenburg, Yolande A L; Barkhof, Frederik; Scheltens, Philip; van der Grond, Jeroen; Rombouts, Serge A R B

2017-01-01

Alzheimer's disease (AD) and behavioral variant frontotemporal dementia (bvFTD) are the most common types of early-onset dementia. We applied longitudinal resting state functional magnetic resonance imaging (fMRI) to delineate functional brain connections relevant for disease progression and diagnostic accuracy. We used two-center resting state fMRI data of 20 AD patients (65.1±8.0 years), 12 bvFTD patients (64.7±5.4 years), and 22 control subjects (63.8±5.0 years) at baseline and 1.8-year follow-up. We used whole-network and voxel-based network-to-region analyses to study group differences in functional connectivity at baseline and follow-up, and longitudinal changes in connectivity within and between groups. At baseline, connectivity between paracingulate gyrus and executive control network, between cuneal cortex and medial visual network, and between paracingulate gyrus and salience network was higher in AD compared with controls. These differences were also present after 1.8 years. At follow-up, connectivity between angular gyrus and right frontoparietal network, and between paracingulate gyrus and default mode network was lower in bvFTD compared with controls, and lower compared with AD between anterior cingulate gyrus and executive control network, and between lateral occipital cortex and medial visual network. Over time, connectivity decreased in AD between precuneus and right frontoparietal network and in bvFTD between inferior frontal gyrus and left frontoparietal network. Longitudinal changes in connectivity between supramarginal gyrus and right frontoparietal network differ between both patient groups and controls. We found disease-specific brain regions with longitudinal connectivity changes. This suggests the potential of longitudinal resting state fMRI to delineate regions relevant for disease progression and for diagnostic accuracy, although no group differences in longitudinal changes in the direct comparison of AD and bvFTD were found.

Effects of Comprehensive School Reform on Student Achievement and School Change: A Longitudinal Multi-Site Study

ERIC Educational Resources Information Center

Sterbinsky, Allan; Ross, Steven M.; Redfield, Doris

2006-01-01

The longitudinal impacts on school change and student achievement of implementing varied Comprehensive School Reform (CSR) models was investigated in 12 elementary schools in diverse geographic locations. Each school was individually matched and compared to a demographically similar control school on measures of school climate, teacher…

Neurocognitive Deficits in Adolescents with Schizophrenia: Longitudinal Stability and Predictive Utility for Short-Term Functional Outcome

ERIC Educational Resources Information Center

Cervellione, Kelly L.; Burdick, Katherine E.; Cottone, John G.; Rhinewine, Joseph P.; Kumra, Sanjiv

2007-01-01

Objective: Previous cross-sectional studies in adolescents with early-onset schizophrenia (EOS; onset of psychotic symptoms by 18 years of age) have reported patterns of generalized neurocognitive deficits as compared to healthy comparison subjects (HCSs). Here, the authors examined the longitudinal stability of neuropsychological deficits in…

Early Indicators of Autism Spectrum Disorders at 12 and 24 Months of Age: A Prospective, Longitudinal Comparative Study

ERIC Educational Resources Information Center

Veness, Carly; Prior, Margot; Bavin, Edith; Eadie, Patricia; Cini, Eileen; Reilly, Sheena

2012-01-01

Prospective questionnaire data from a longitudinal population sample on children with autism spectrum disorders (ASD), developmental delay, specific language impairment, or typical development (TD), were collected at ages eight, 12 and 24 months, via the Communication and Symbolic Behavior Scale Developmental Profile (CSBS)--Infant Toddler…

Just Another Club? The Distinctiveness of the Relation between Religious Service Attendance and Adolescent Psychosocial Adjustment

ERIC Educational Resources Information Center

Good, Marie; Willoughby, Teena; Fritjers, Jan

2009-01-01

This study used hierarchical linear modeling to compare longitudinal patterns of adolescent religious service attendance and club attendance, and to contrast the longitudinal relations between adolescent adjustment and religious service versus club attendance. Participants included 1050 students (47% girls) encompassing a school district in…

A longitudinal comparative study of the physical and mental health problems of affected residents of the firework disaster Enschede, The Netherlands.

PubMed

Grievink, L; van der Velden, P G; Stellato, R K; Dusseldorp, A; Gersons, B P R; Kleber, R J; Lebret, E

2007-05-01

After the firework disaster in Enschede, The Netherlands, on 13 May 2000, a longitudinal health study was carried out. Study questions were: (1) did the health status change over this period; and (2) how is the health status 18 months after the disaster compared with controls? A longitudinal comparative study with two surveys at 3 weeks and 18 months after the disaster. A control group for the affected residents was included in the second survey. Respondents filled in a set of validated questionnaires measuring their physical and mental health problems. The prevalence of physical and emotional role limitations, severe sleeping problems, feelings of depression and anxiety, as well as intrusion and avoidance decreased from 3 weeks to 18 months after the disaster for the affected residents. Independent of background characteristics and other life events, residents had 1.5 to three times more health problems than the control group; for example, physical role limitations (odds ratio [OR]=1.5, 95% confidence interval [CI] 1.2-2.0) and anxiety (OR=3.1, 95% CI 2.4-4.2). Although health problems decreased compared with 3 weeks after the disaster, 18 months after the disaster, the affected residents had more health problems than the people from the control group.

Developing a national strategy to prevent dementia: Leon Thal Symposium 2009.

PubMed

Khachaturian, Zaven S; Barnes, Deborah; Einstein, Richard; Johnson, Sterling; Lee, Virginia; Roses, Allen; Sager, Mark A; Shankle, William R; Snyder, Peter J; Petersen, Ronald C; Schellenberg, Gerard; Trojanowski, John; Aisen, Paul; Albert, Marilyn S; Breitner, John C S; Buckholtz, Neil; Carrillo, Maria; Ferris, Steven; Greenberg, Barry D; Grundman, Michael; Khachaturian, Ara S; Kuller, Lewis H; Lopez, Oscar L; Maruff, Paul; Mohs, Richard C; Morrison-Bogorad, Marcelle; Phelps, Creighton; Reiman, Eric; Sabbagh, Marwan; Sano, Mary; Schneider, Lon S; Siemers, Eric; Tariot, Pierre; Touchon, Jacques; Vellas, Bruno; Bain, Lisa J

2010-03-01

Among the major impediments to the design of clinical trials for the prevention of Alzheimer's disease (AD), the most critical is the lack of validated biomarkers, assessment tools, and algorithms that would facilitate identification of asymptomatic individuals with elevated risk who might be recruited as study volunteers. Thus, the Leon Thal Symposium 2009 (LTS'09), on October 27-28, 2009 in Las Vegas, Nevada, was convened to explore strategies to surmount the barriers in designing a multisite, comparative study to evaluate and validate various approaches for detecting and selecting asymptomatic people at risk for cognitive disorders/dementia. The deliberations of LTS'09 included presentations and reviews of different approaches (algorithms, biomarkers, or measures) for identifying asymptomatic individuals at elevated risk for AD who would be candidates for longitudinal or prevention studies. The key nested recommendations of LTS'09 included: (1) establishment of a National Database for Longitudinal Studies as a shared research core resource; (2) launch of a large collaborative study that will compare multiple screening approaches and biomarkers to determine the best method for identifying asymptomatic people at risk for AD; (3) initiation of a Global Database that extends the concept of the National Database for Longitudinal Studies for longitudinal studies beyond the United States; and (4) development of an educational campaign that will address public misconceptions about AD and promote healthy brain aging. 2010. Published by Elsevier Inc.

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.

Testing the Efficacy of Two New Variants of Recasts with Standard Recasts in Communicative Conversational Settings: An Exploratory Longitudinal Study

ERIC Educational Resources Information Center

Wacha, Richard Charles; Liu, Yeu-Ting

2017-01-01

The purpose of this exploratory longitudinal study was to evaluate the efficacy of two new forms of recasts (i.e., elaborated and paraphrased recasts), each of which was designed to be more in accordance with contested views of input processing. The effectiveness of the two new forms of recasts was compared to that of conventional standard…

Mixed-effects location and scale Tobit joint models for heterogeneous longitudinal data with skewness, detection limits, and measurement errors.

PubMed

Lu, Tao

2017-01-01

The joint modeling of mean and variance for longitudinal data is an active research area. This type of model has the advantage of accounting for heteroscedasticity commonly observed in between and within subject variations. Most of researches focus on improving the estimating efficiency but ignore many data features frequently encountered in practice. In this article, we develop a mixed-effects location scale joint model that concurrently accounts for longitudinal data with multiple features. Specifically, our joint model handles heterogeneity, skewness, limit of detection, measurement errors in covariates which are typically observed in the collection of longitudinal data from many studies. We employ a Bayesian approach for making inference on the joint model. The proposed model and method are applied to an AIDS study. Simulation studies are performed to assess the performance of the proposed method. Alternative models under different conditions are compared.

Which language declines more? longitudinal versus cross-sectional decline of picture naming in bilinguals with Alzheimer's disease.

PubMed

Ivanova, Iva; Salmon, David P; Gollan, Tamar H

2014-05-01

In this study, we investigated dual-language decline in non-balanced bilinguals with probable Alzheimer's disease (AD) both longitudinally and cross-sectionally. We examined patients' naming accuracy on the Boston Naming Test (BNT: Kaplan et al., 1983) over three testing sessions (longitudinal analysis) and compared their performance to that of matched controls (cross-sectional analysis). We found different longitudinal and cross-sectional patterns of decline: Longitudinally, the non-dominant language seemed to decline more steeply than the dominant language, but, cross-sectionally, differences between patients and controls were larger for the dominant than for the non-dominant language, especially at the initial testing session. This differential pattern of results for cross-sectional versus longitudinal decline was supported by correlations between decline measures and BNT item characteristics. Further studies will be needed to better characterize the nature of linguistic decline in bilinguals with AD; however, these results suggest that representational robustness of individual lexical representations, rather than language membership, might determine the time course of decline for naming in bilinguals with AD.

Measuring Longitudinal Gains in Student Learning: A Comparison of Rasch Scoring and Summative Scoring Approaches

ERIC Educational Resources Information Center

Zhao, Yue; Huen, Jenny M. Y.; Chan, Y. W.

2017-01-01

This study pioneers a Rasch scoring approach and compares it to a conventional summative approach for measuring longitudinal gains in student learning. In this methodological note, our proposed methodology is demonstrated using an example of rating scales in a student survey as part of a higher education outcome assessment. Such assessments have…

Diet quality is lower and energy intake greater on weekends than weekdays: A one-year longitudinal study of midlife women

USDA-ARS?s Scientific Manuscript database

Objective: To test differences in dietary intake by individual day and on weekends (Friday, Saturday, Sunday) compared to weekdays using energy and macronutrient intake, food groupings and Healthy Eating Index-2010 diet quality scores. Methods: Longitudinal design; 52 women ages 40-60 y completed o...

A Longitudinal Study of Vocabulary Size and Composition in Low Risk Preterm Children

ERIC Educational Resources Information Center

Pérez-Pereira, Miguel; Cruz, Raquel

2018-01-01

The vocabulary size and composition of one group of full-term and three groups of low risk preterm children with different gestational ages (GA) were longitudinally compared at 10, 22 and 30 months of age. Expressive vocabulary development was assessed through the CDI. Cognitive development was also assessed at 22 months (Batelle Developmental…

A Longitudinal Examination of Risky Sexual Behaviors among Canadian and Italian Adolescents: Considering Individual, Parental, and Friend Characteristics

ERIC Educational Resources Information Center

Boislard P., Marie-Aude; Poulin, Francois; Kiesner, Jeff; Dishion, Thomas J.

2009-01-01

In this study, two longitudinal models of early adolescent risky sexual behaviors (RSB) were compared using a pooled sample of 267 Canadian and Italian adolescents (55% females; 53% Canadians) assessed yearly from grade 8 to 10. We focused on parenting practices (monitoring, control, limit setting), adolescent problem behaviors (antisocial…

Comparing Field-Teaching Experiences: A Longitudinal Examination of Preservice and First-Year Teacher Perspectives

ERIC Educational Resources Information Center

Bartolome, Sarah J.

2017-01-01

The purpose of this longitudinal study was to examine preservice and first-year music educators' perspectives on fieldwork activities embedded within a music teacher preparation program. One cohort of students was tracked for 2.5 years as they participated in an elementary teaching practicum, fulfilled the student teaching internship, and…

Differential rate in decline in ovarian reserve markers in women with polycystic ovary syndrome compared with control subjects: results of a longitudinal study.

PubMed

Ahmad, Asima K; Kao, Chia-Ning; Quinn, Molly; Lenhart, Nikolaus; Rosen, Mitchell; Cedars, Marcelle I; Huddleston, Heather

2018-03-01

To estimate rates of ovarian aging in polycystic ovary syndrome (PCOS) subjects versus a community control population. Longitudinal. Tertiary academic center. PCOS subjects diagnosed according to the 2004 Rotterdam criteria were systematically enrolled in a PCOS cohort study. The comparison control subjects were from the Ovarian Aging study, a prospective longitudinal study of ovarian aging in healthy women with regular menstrual cycles. Clinical data collection over two study visits. Antral follicle count (AFC), ovarian volume (OV), and antimüllerian hormone level (AMH). PCOS subjects were found to have higher baseline values for all ovarian reserve markers compared with control subjects. Univariate models indicated that, compared with control subjects, PCOS patients experienced significantly faster rates of decline for both AFC and AMH. Change in OV did not differ significantly. To account for potential confounder effects, multiple analysis of covariance models were evaluated for the best fit, considering age, body mass index, and baseline ovarian reserve markers. Adjusted models demonstrated that PCOS patients do not experience a significant difference in AFC decline compared with control subjects, but they do experience a faster rate of decline in AMH (P<.01) and slower rate of decline in OV (P<.01). Ovarian aging in PCOS is characterized by a more rapid decline in AMH and a slower decline in OV compared with control subjects. Copyright © 2017 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

A comparison of response rates in the English Longitudinal Study of Ageing and the Health and Retirement Study

PubMed Central

Cheshire, Hayley; Ofstedal, Mary Beth; Scholes, Shaun; Schroeder, Mathis

2013-01-01

Survey response rates are an important measure of the quality of a survey; this is true for both longitudinal and cross-sectional surveys. However, the concept of a response rate in the context of a panel survey is more complex than is the case for a cross-sectional survey. There are typically many different response rates that can be calculated for a panel survey, each of which may be relevant for a specific purpose. The main objective of our paper is to document and compare response rates for two long-term panel studies of ageing, the English Longitudinal Study of Ageing (ELSA) and the Health and Retirement Study (HRS) in the United States. To guide our selection and calculation of response rates for the two studies, we use a framework that was developed by Peter Lynn (2005) and present several different types of longitudinal response rates for the two surveys. We discuss similarities and differences in the study designs and protocols and how some of the differences affect comparisons of response rates across the two studies. PMID:24432049

A Proposed Approach for Joint Modeling of the Longitudinal and Time-To-Event Data in Heterogeneous Populations: An Application to HIV/AIDS's Disease.

PubMed

Roustaei, Narges; Ayatollahi, Seyyed Mohammad Taghi; Zare, Najaf

2018-01-01

In recent years, the joint models have been widely used for modeling the longitudinal and time-to-event data simultaneously. In this study, we proposed an approach (PA) to study the longitudinal and survival outcomes simultaneously in heterogeneous populations. PA relaxes the assumption of conditional independence (CI). We also compared PA with joint latent class model (JLCM) and separate approach (SA) for various sample sizes (150, 300, and 600) and different association parameters (0, 0.2, and 0.5). The average bias of parameters estimation (AB-PE), average SE of parameters estimation (ASE-PE), and coverage probability of the 95% confidence interval (CP) among the three approaches were compared. In most cases, when the sample sizes increased, AB-PE and ASE-PE decreased for the three approaches, and CP got closer to the nominal level of 0.95. When there was a considerable association, PA in comparison with SA and JLCM performed better in the sense that PA had the smallest AB-PE and ASE-PE for the longitudinal submodel among the three approaches for the small and moderate sample sizes. Moreover, JLCM was desirable for the none-association and the large sample size. Finally, the evaluated approaches were applied on a real HIV/AIDS dataset for validation, and the results were compared.

Children's Behavior Problems in the United States and Great Britain

ERIC Educational Resources Information Center

Parcel, Toby L.; Campbell, Lori Ann; Zhong, Wenxuan

2012-01-01

We analyze the effects of family capital on child behavior problems in the United States and Great Britain by comparing a longitudinal survey sample of 5- to 13-year-old children from the 1994 National Longitudinal Survey of Youth (N = 3,864) with a similar sample of children from the 1991 National Child Development Study "British Child"…

The Role of Parents' Control in Early Adolescents' Psychological Functioning: A Longitudinal Investigation in the United States and China

ERIC Educational Resources Information Center

Wang, Qian; Pomerantz, Eva M.; Chen, Huichang

2007-01-01

This research compared the effects over time of parents' control and autonomy support on children's functioning in the United States and China. American and Chinese (N = 806) seventh graders (mean age = 12.73 years) participated in a 6-month longitudinal study. Children reported on their parents' psychological control, psychological autonomy…

Factor Structure and Measurement Invariance of a 10-Item Decisional Balance Scale: Longitudinal and Subgroup Examination within an Adult Diabetic Sample

ERIC Educational Resources Information Center

Pickering, Michael A.; Plotnikoff, Ronald C.

2009-01-01

This study explores the longitudinal and subgroup measurement properties of a 10-item, physical activity decisional balance scale, previously published by Plotnikoff, Blanchard, Hotz, and Rhodes (2001), within a diabetic sample of Canadian adults. Results indicated that a three-factor measurement model consistently improved model fit compared to…

Longitudinal Trajectories of Gestural and Linguistic Abilities in Very Preterm Infants in the Second Year of Life

ERIC Educational Resources Information Center

Sansavini, Alessandra; Guarini, Annalisa; Savini, Silvia; Broccoli, Serena; Justice, Laura; Alessandroni, Rosina; Faldella, Giacomo

2011-01-01

The present study involved a systematic longitudinal analysis, with three points of assessment in the second year of life, of gestures/actions, word comprehension, and word production in a sample of very preterm infants compared to a sample of full-term infants. The relationships among these competencies as well as their predictive value on…

A comparison of multiple imputation methods for incomplete longitudinal binary data.

PubMed

Yamaguchi, Yusuke; Misumi, Toshihiro; Maruo, Kazushi

2018-01-01

Longitudinal binary data are commonly encountered in clinical trials. Multiple imputation is an approach for getting a valid estimation of treatment effects under an assumption of missing at random mechanism. Although there are a variety of multiple imputation methods for the longitudinal binary data, a limited number of researches have reported on relative performances of the methods. Moreover, when focusing on the treatment effect throughout a period that has often been used in clinical evaluations of specific disease areas, no definite investigations comparing the methods have been available. We conducted an extensive simulation study to examine comparative performances of six multiple imputation methods available in the SAS MI procedure for longitudinal binary data, where two endpoints of responder rates at a specified time point and throughout a period were assessed. The simulation study suggested that results from naive approaches of a single imputation with non-responders and a complete case analysis could be very sensitive against missing data. The multiple imputation methods using a monotone method and a full conditional specification with a logistic regression imputation model were recommended for obtaining unbiased and robust estimations of the treatment effect. The methods were illustrated with data from a mental health research.

Longitudinal plasma metanephrines preceding pheochromocytoma diagnosis: a retrospective case-control serum repository study.

PubMed

Olson, S W; Yoon, S; Baker, T; Prince, L K; Oliver, D; Abbott, K C

2016-03-01

Plasma metanephrines (PMN) are highly sensitive for diagnosis of pheochromocytoma, but the natural history of PMN before pheochromocytoma diagnosis has not been previously described. The aim of the study was to compare the progression of PMN before pheochromocytoma diagnosis to matched healthy and essential hypertension disease controls. A retrospective case-control Department of Defense Serum Repository (DoDSR) study. We performed a DoDSR study that compared three longitudinal pre-diagnostic PMN for 30 biopsy-proven pheochromocytoma cases to three longitudinal PMN for age, sex, race, and age of serum sample matched healthy and essential hypertension disease controls. Predominant metanephrine (MN) or normetanephrine (NMN) production was identified for each case and converted to a percentage of the upper limit of normal to allow analysis of all cases together. PMN were measured by Quest Diagnostics. The predominant plasma metanephrine (PPM) was >100 and 300% of the upper limit of normal a median of 6.6 and 4.1 years before diagnosis respectively. A greater percentage of pheochromocytoma patients had a PPM >100 and >300% of the upper limit of normal compared with combined healthy and essential hypertension disease controls <2, 2-8, and >8 years prior to diagnosis. For patients with a baseline PPM 90-300% of the upper limit of normal, a 25% rate of rise per year was 100% specific for pheochromocytoma. PPMs elevate years before diagnosis which suggests that delayed diagnoses are common. For mild PMN elevations, follow-up longitudinal PMN trends may provide a highly specific and economical diagnostic tool. © 2016 European Society of Endocrinology.

LONGITUDINAL COHORT METHODS STUDIES

EPA Science Inventory

Accurate exposure classification tools are required to link exposure with health effects in epidemiological studies. Exposure classification for occupational studies is relatively easy compared to predicting residential childhood exposures. Recent NHEXAS (Maryland) study articl...

The Essential Role of Curricular Analyses in Comparative Studies of Mathematics Achievement: Developing "Fair" Tests

ERIC Educational Resources Information Center

Chavez, Oscar; Papick, Ira; Ross, Dan J.; Grouws, Douglas A.

2010-01-01

The purpose of this paper was to describe the process of development of assessment instruments for the Comparing Options in Secondary Mathematics: Investigating Curriculum (COSMIC) project. The COSMIC project was a three-year longitudinal comparative study focusing on evaluating high school students' mathematics learning from two distinct…

Student Achievement in Ohio Charter Schools: A Comparative and Longitudinal Study

ERIC Educational Resources Information Center

Kotler, Ruth M.

2012-01-01

The purpose of this study was to investigate fifth-grade student achievement in Ohio public charter schools as compared to student achievement in traditional public schools, and to determine whether the performance of charter schools changed over time. Research questions asked 1) how does student achievement in Ohio's public charters compare to…

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.

Magnetic resonance elastography to observe deep areas: comparison of external vibration systems.

PubMed

Suga, Mikio; Obata, Takayuki; Hirano, Masaya; Tanaka, Takashi; Ikehira, Hiroo

2007-01-01

MRE methods deform the sample using an external vibration system. We have been using a transverse driver, which generates shear waves at the object surface. One of the problems is that shear waves rapidly attenuate at the surface of tissue and do not propagate into the body. In this study, we compared the shear waves generated by transverse and longitudinal drivers. The longitudinal driver was found to induce shear waves deep inside a porcine liver phantom. These results suggest that the longitudinal driver will allow measurement of the shear modulus deep inside the body.

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

PubMed

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

2018-01-01

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

Early Impairment of Cardiac Function and Asynchronization of Systemic Amyloidosis with Preserved Ejection Fraction Using Two-Dimensional Speckle Tracking Echocardiography.

PubMed

Huang, He; Jing, Xian-chao; Hu, Zhang-xue; Chen, Xi; Liu, Xiao-qin

2015-12-01

To observe the ventricular global and regional function of the patients with systemic amyloidosis using two-dimensional speckle tracking echocardiography. The study enrolled 31 consecutive biopsy-proved patients with systemic amyloidosis who underwent echocardiographic examination and EF ≥ 55% and 37 age- and gender-matched healthy controls. We compared systolic strain and strain rate, diastolic strain rate, time to peak strain, peak delay time in longitudinal, radial, circumferential directions in 16 left ventricular segments. The global peak systolic longitudinal and radial strain of left ventricle, peak systolic longitudinal strain and strain rate, diastolic strain rate of right ventricular free wall were also compared. (1) Global peak systolic longitudinal strain (GPSLS), peak systolic longitudinal strain (PSLS) and strain rate (PSLSR), peak early diastolic longitudinal strain rate (PELSR) in 16 segments were decreased in case (P < 0.05). (2) Peak systolic radial strain and strain rate of inferoseptum and inferolateral at the level of papillary muscle were lower (P < 0.05), and peak early diastolic radial strain rate (PERSR) was reduced (P < 0.05). (3) Peak early diastolic circumferential strain rate was lower (P < 0.05). (4) Time to peak systolic longitudinal, radial, circumferential strain was longer, and peak delay time at the same level retarded (P < 0.05). (5) Into right ventricular wall, PSLS and PSLSR at mid-segment, and PSLSR, PELSR, peak atrial systolic longitudinal strain rate (PALSR) at basal were reduced (P < 0.05). (6) Inverse correlation between interventricular septum (IVS) thickness and GPSLS and GPSRS was found (P < 0.05). Systolic and diastolic dysfunction existed in systemic amyloidosis with preserved EF. Mechanical contraction disorder may be one reason for systolic dysfunction. GPLSR and GPRSR were negatively related to IVS thickness. © 2015, Wiley Periodicals, Inc.

[Origin of motion in the human ureter: mechanics, energetics and kinetics of the myosin molecular motors].

PubMed

Vargiu, Romina; Perinu, Anna; De Lisa, Antonello; Tintrup, Frank; Manca, Francesco; Mancinelli, Rino

2012-01-01

Ureteral peristalsis is the result of coordinated mechanical motor performance of longitudinal and circular smooth muscle layer of the ureter wall. The main aim of this study was to characterize in smooth muscle of proximal segments of human ureter, the mechanical properties at level of muscle tissue and at level of myosin molecular motors. Ureteral samples were collected from 15 patients, who underwent nephrectomy for renal cancer. Smooth muscle strips longitudinally and circularly oriented from proximal segments of human ureter were used for the in vitro experiments. Mechanical indices including the maximum unloaded shortening velocity (Vmax), and the maximum isometric tension (P0) normalized per cross-sectional area, were determined in vitro determined in electrically evoked contractions of longitudinal and circular smooth muscle strips. Myosin cross-bridge (CB) number per mm2 (Ψ) the elementary force per single CB (Ψ) and kinetic parameters were calculated in muscle strips, using Huxley's equations adapted to nonsarcomeric muscles. Longitudinal smooth muscle strips exhibited a significantly (p<0.05) faster Vmax (63%) and a higher P0 (40%), if compared to circular strips. Moreover, longitudinal muscle strips showed a significantly higher unitary force (Ψ) per CB. However, no significant differences were observed in CB number, the attachment (f1) and the detachment (g2) rate constants between longitudinal and circular muscle strips. The main result obtained in the present work documents that the mechanical, energetic and unitary forces per CB of longitudinal layer of proximal ureter are better compared to the circular one; these preliminary findings suggested, unlike intestinal smooth muscle, a major role of longitudinal smooth muscle layer in the ureter peristalsis.

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

PubMed

Mychasiuk, R; Benzies, K

2012-09-01

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

Longitudinal changes in hematocrit in hypertensive chronic kidney disease: results from the African-American Study of Kidney Disease and Hypertension (AASK)

PubMed Central

Chen, Teresa K.; Estrella, Michelle M.; Astor, Brad C.; Greene, Tom; Wang, Xuelei; Grams, Morgan E.; Appel, Lawrence J.

2015-01-01

Background Anemia is common in chronic kidney disease (CKD) and associated with poor outcomes. In cross-sectional studies, lower estimated glomerular filtration rate (eGFR) has been associated with increased risk for anemia. The aim of this study was to determine how hematocrit changes as eGFR declines and what factors impact this longitudinal association. Methods We followed 1094 African-Americans with hypertensive nephropathy who participated in the African-American Study of Kidney Disease and Hypertension. Mixed effects models were used to determine longitudinal change in hematocrit as a function of eGFR. Interaction terms were used to assess for differential effects of age, gender, baseline eGFR, baseline proteinuria, malnutrition and inflammation on eGFR-associated declines in hematocrit. In sensitivity analyses, models were run using iGFR (by renal clearance of I125 iothalamate) in place of eGFR. Results At baseline, mean hematocrit was 39% and 441 (40%) individuals had anemia. The longitudinal relationship between eGFR and hematocrit differed by baseline eGFR and was steeper when baseline eGFR was <45 mL/min/1.73 m2. For example, the absolute decline in hematocrit per 10 mL/min/1.73 m2 decline in longitudinal eGFR was −3.7, −1.3 and −0.5% for baseline eGFR values of 20, 40 and 60 mL/min/1.73 m2, respectively (P < 0.001 comparing the longitudinal association between baseline eGFR = 40 or 60 versus baseline eGFR = 20 mL/min/1.73 m2). Similarly, male sex, younger age (<65 years) and higher baseline proteinuria (protein-to-creatinine ratio >0.22) were associated with greater hematocrit declines per unit decrease in longitudinal eGFR compared with female sex, older age and low baseline proteinuria, respectively (P-interaction <0.05 for each comparison). The longitudinal eGFR–hematocrit association did not differ by body mass index, serum albumin or C-reactive protein. Conclusions Men, younger individuals and those with low baseline eGFR (<45 mL/min/1.73 m2) or baseline proteinuria are particularly at risk for eGFR-related declines in hematocrit. PMID:25817226

Reliability of measuring sciatic and tibial nerve movement with diagnostic ultrasound during a neural mobilisation technique.

PubMed

Ellis, Richard; Hing, Wayne; Dilley, Andrew; McNair, Peter

2008-08-01

Diagnostic ultrasound provides a technique whereby real-time, in vivo analysis of peripheral nerve movement is possible. This study measured sciatic nerve movement during a "slider" neural mobilisation technique (ankle dorsiflexion/plantar flexion and cervical extension/flexion). Transverse and longitudinal movement was assessed from still ultrasound images and video sequences by using frame-by-frame cross-correlation software. Sciatic nerve movement was recorded in the transverse and longitudinal planes. For transverse movement, at the posterior midthigh (PMT) the mean value of lateral sciatic nerve movement was 3.54 mm (standard error of measurement [SEM] +/- 1.18 mm) compared with anterior-posterior/vertical (AP) movement of 1.61 mm (SEM +/- 0.78 mm). At the popliteal crease (PC) scanning location, lateral movement was 6.62 mm (SEM +/- 1.10 mm) compared with AP movement of 3.26 mm (SEM +/- 0.99 mm). Mean longitudinal sciatic nerve movement at the PMT was 3.47 mm (SEM +/- 0.79 mm; n = 27) compared with the PC of 5.22 mm (SEM +/- 0.05 mm; n = 3). The reliability of ultrasound measurement of transverse sciatic nerve movement was fair to excellent (Intraclass correlation coefficient [ICC] = 0.39-0.76) compared with excellent (ICC = 0.75) for analysis of longitudinal movement. Diagnostic ultrasound presents a reliable, noninvasive, real-time, in vivo method for analysis of sciatic nerve movement.

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

PubMed Central

2014-01-01

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

Nuclear longitudinal form factors for axially deformed charge distributions expanded by nonorthogonal basis functions

NASA Astrophysics Data System (ADS)

Liu, Jian; Zhang, Jinjuan; Xu, Chang; Ren, Zhongzhou

2017-05-01

In this paper, the nuclear longitudinal form factors are systematically studied from the intrinsic charge multipoles. For axially deformed nuclei, two different types of density profiles are used to describe their charge distributions. For the same charge distributions expanded with different basis functions, the corresponding longitudinal form factors are derived and compared with each other. Results show the multipoles Cλ of longitudinal form factors are independent of the basis functions of charge distributions. Further numerical calculations of longitudinal form factors of 12C indicates that the C 0 multipole reflects the contributions of spherical components of all nonorthogonal basis functions. For deformed nuclei, their charge RMS radii can also be determined accurately by the C 0 measurement. The studies in this paper examine the model-independent properties of electron scattering, which are useful for interpreting electron scattering experiments on exotic deformed nuclei. Supported by National Natural Science Foundation of China (11505292, 11175085, 11575082, 11235001, 11275138, and 11447226), by Shandong Provincial Natural Science Foundation, China (BS2014SF007), Fundamental Research Funds for Central Universities (15CX02072A).

Life satisfaction and resilience in medical school – a six-year longitudinal, nationwide and comparative study

PubMed Central

Kjeldstadli, Kari; Tyssen, Reidar; Finset, Arnstein; Hem, Erlend; Gude, Tore; Gronvold, Nina T; Ekeberg, Oivind; Vaglum, Per

2006-01-01

Background This study examined the relationship between life satisfaction among medical students and a basic model of personality, stress and coping. Previous studies have shown relatively high levels of distress, such as symptoms of depression and suicidal thoughts in medical undergraduates. However despite the increased focus on positive psychological health and well-being during the past decades, only a few studies have focused on life satisfaction and coping in medical students. This is the first longitudinal study which has identified predictors of sustained high levels of life satisfaction among medical students. Methods This longitudinal, nationwide questionnaire study examined the course of life satisfaction during medical school, compared the level of satisfaction of medical students with that of other university students, and identified resilience factors. T-tests were used to compare means of life satisfaction between and within the population groups. K-means cluster analyses were applied to identify subgroups among the medical students. Analysis of Variance (ANOVA) and logistic regression analyses were used to compare the subgroups. Results Life satisfaction decreased during medical school. Medical students were as satisfied as other students in the first year of study, but reported less satisfaction in their graduation year. Medical students who sustained high levels of life satisfaction perceived medical school as interfering less with their social and personal life, and were less likely to use emotion focused coping, such as wishful thinking, than their peers. Conclusion Medical schools should encourage students to spend adequate time on their social and personal lives and emphasise the importance of health-promoting coping strategies. PMID:16984638

Ozil IP torsional mode versus combined torsional/longitudinal microcoaxial phacoemulsification.

PubMed

Helvacioglu, Firat; Tunc, Zeki; Yeter, Celal; Oguzhan, Hasan; Sencan, Sadik

2012-01-01

To compare the safety and efficacy of microcoaxial phacoemulsification surgeries performed with the Ozil Intelligent Phaco (IP) torsional mode and combined torsional/longitudinal ultrasound (US) mode using the Infiniti Vision System (Alcon Laboratories). In this prospective randomized comparative study, 60 eyes were assigned to 2.2-mm microcoaxial phacoemulsification using the Ozil IP torsional mode (group 1) or combined torsional/longitudinal US mode (group 2). The primary outcome measures were US time (UST), cumulative dissipated energy (CDE), longitudinal and torsional ultrasound amplitudes, mean operation time, mean volume of balanced salt solution (BSS) used, and surgical complications. Both groups included 30 eyes. Mean UST, CDE, and longitudinal and torsional ultrasound amplitudes in group 1 were 1 minute 15±34.33 seconds, 8.74±5.64, 0.43±0.74, and 25.56±8.56, respectively, and these parameters in group 2 were 1 minute 40±51.44 seconds, 9.28±5.99, 3.64±1.55, and 3.71±1.34, respectively. UST and longitudinal amplitudes were found to be significantly low in group 1 (p<0.001, p<0.001), whereas torsional amplitude was found to be significantly high in this group (p=0.001). Mean volumes of BSS used in groups 1 and 2 were 63.30±18.00 cc and 84.50±28.65 cc, respectively (p=0.001). The Ozil IP torsional mode may provide more effective lens removal than the combined torsional/longitudinal US mode with a lower UST and volume of BSS used.

Assessment of regional systolic and diastolic myocardial function using tissue Doppler and strain imaging in dogs with dilated cardiomyopathy.

PubMed

Chetboul, Valérie; Gouni, Vassiliki; Sampedrano, Carolina Carlos; Tissier, Renaud; Serres, François; Pouchelon, Jean-Louis

2007-01-01

Tissue Doppler Imaging (TDI) or strain (St) imaging could provide sensitive indices for early detection and treatment follow-up of canine dilated cardiomyopathy (DCM). Analysis of TDI and St features in dogs with overt DCM is a prerequisite before using these new criteria in prospective screenings of predisposed families or in clinical trials. Radial and longitudinal right and left myocardial motion, assessed by TDI and St variables, is altered in dogs with DCM. Case records for 26 dogs; 14 with DCM and 12 healthy controls of comparable age and weight were reviewed. A retrospective analysis was conducted of conventional echocardiography, 2-dimensional color TDI, and St imaging data. The DCM group was characterized by decreases in radial and longitudinal systolic velocity gradients of the left ventricular free wall (LVFW), radial and longitudinal absolute values of peak systolic St of the LVFW, and longitudinal systolic right ventricular (RV) velocities (all P < .001 versus control) associated with longitudinal postsystolic contraction waves in 7/14 dogs. Early diastolic LVFW velocities also were decreased for longitudinal (P < .01) and radial (P < .05) motions. All radial LVFW, longitudinal basal LVFW, and RV systolic velocities were negatively correlated with heart rate (P < .01). LV contractility along both the short and long axes is impaired in dogs with spontaneous DCM, as is systolic RV and diastolic LVFW function. These myocardial alterations are associated with an inverse force-frequency relationship. Studies now are needed to determine the comparative sensitivity of TDI and St variables for the early detection of canine DCM.

The effects of airbags and seatbelts on occupant injury in longitudinal barrier crashes.

PubMed

Gabauer, Douglas J; Gabler, Hampton C

2010-02-01

Longitudinal barriers, such as guardrails, are designed to prevent a vehicle that leaves the roadway from impacting a more dangerous object while minimizing the risk of injury to the vehicle occupants. Current full-scale test procedures for these devices do not consider the effect of occupant restraints such as seatbelts and airbags. The purpose of this study was to determine the extent to which restraints are used or deployed in longitudinal barrier collisions and their subsequent effect on occupant injury. Binary logistic regression models were generated to predict occupant injury risk using data from the National Automotive Sampling System / Crashworthiness Data System from 1997 through 2007. In tow-away longitudinal barrier crashes, airbag deployment rates were 70% for airbag-equipped vehicles. Compared with unbelted occupants without an airbag available, seat belt restrained occupants with an airbag available had a dramatically decreased risk of receiving a serious (MAIS 3+) injury (odds-ratio (OR)=0.03; 95% CI: 0.004-0.24). A similar decrease was observed among those restrained by seat belts, but without an airbag available (OR=0.03; 95% CI: 0.001- 0.79). No significant differences in risk of serious injuries were observed between unbelted occupants with an airbag available compared with unbelted occupants without an airbag available (OR=0.53; 95% CI=0.10-2.68). This study refutes the perception in the roadside safety community that airbags rarely deploy in frontal barrier crashes, and suggests that current longitudinal barrier occupant risk criteria may over-estimate injury potential for restrained occupants involved in a longitudinal barrier crash. Copyright 2010 Elsevier Ltd. All rights reserved.

De qeurvian tenosynovitis: clinical outcomes of surgical treatment with longitudinal and transverse incision.

PubMed

Abrisham, Syyed Jalil; Karbasi, Mohammad Hosein Akhavan; Zare, Jalil; Behnamfar, Zahra; Tafti, Arefah Dehghani; Shishesaz, Behzad

2011-03-01

De Quervain disease is a mechanical tenosynovitis due to inadequacy volume between abductor pollicis longus, extensor pollicis brevis and their tunnel. Treatment methods include immobilization, steroid injections, and operation. For the first time Fritz De Quervain described surgical treatment of this disease. Since then, various ways of treatment have been reported. The purpose of this study is to compare the clinical outcomes of a longitudinal incision with a transverse incision in De Quervain disease. This was a randomized controlled clinical trial conducted in three hospitals in Iran, Yazd from March 2003 to September 2008. One hundred-twenty patients with De Quervain disease who did not respond to conservative treatment were operated with two different incisions. The patients were followed for three months to compare the surgical outcomes. During a three month follow-up, a significant difference was shown between the two methods (p=0.03). Results of surgical treatment with longitudinal incision were excellent (only 5 hypertrophic scars), but there were 13 postoperative complaints with transverse incision. According to our findings, longitudinal incision in surgical treatment of De Quervain disease is better than transverse incision.

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

PubMed

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

2012-01-01

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

Opportunities and Challenges in Using Studies without a Control Group in Comparative Effectiveness Reviews

ERIC Educational Resources Information Center

Paulus, Jessica K.; Dahabreh, Issa J.; Balk, Ethan M.; Avendano, Esther E.; Lau, Joseph; Ip, Stanley

2014-01-01

When examining the evidence on therapeutic interventions to answer a comparative effectiveness research question, one should consider all studies that are informative on the interventions' causal effects. "Single group studies" evaluate outcomes longitudinally in cohorts of subjects who are managed with a single treatment strategy.…

A longitudinal investigation of nutrition and dietary patterns in children of mothers with eating disorders.

PubMed

Easter, Abigail; Naumann, Ulrike; Northstone, Kate; Schmidt, Ulrike; Treasure, Janet; Micali, Nadia

2013-07-01

To investigate dietary patterns and nutritional intake in children of mothers with eating disorders. Mothers (N = 9423) from a longitudinal general population birth cohort study, the Avon Longitudinal Study of Parents and Children, completed Food Frequency Questionnaires on their children at 3, 4, 7, and 9 years of age. Macronutrient intake was estimated, and dietary patterns were obtained using principal components analysis. Linear regression and mixed-effects models were used to assess dietary patterns and nutritional intake among children of women with lifetime anorexia nervosa (AN, n = 140), bulimia nervosa (BN, n = 170), or AN+BN (n = 71), compared with children of women without eating disorders (unexposed women, n = 9037). Children in the maternal AN and BN groups had higher scores on the "health conscious/vegetarian" dietary pattern compared with unexposed children. Less adherence to the "traditional" dietary pattern was observed in children of exposed mothers, with more pronounced differences in early childhood. Children of women with AN and BN had higher intake of energy and children of women with BN had higher intake of carbohydrates and starch and lower intake of fat, compared with children in the unexposed group. Maternal eating disorders are associated with altered offspring dietary patterns and macronutrient intake. Longitudinal changes in patterns of diet in children of women with eating disorders may increase the risk of weight gain or disordered eating later in life. Copyright © 2013 Mosby, Inc. All rights reserved.

Health Behaviors of Nursing Students: A Longitudinal Study.

ERIC Educational Resources Information Center

Clement, Madeleine; Jankowski, Louis W.; Bouchard, Louise; Perreault, Michel; Lepage, Yves

2002-01-01

A 3-year study compared 52 undergraduate nursing students with 93 education majors and with the general population. No significant differences among students on 9 health behaviors appeared. Compared with the general population, nursing students had inadequate time for sleep, exercise, and eating breakfast. (Contains 77 references.) (SK)

The SAVRY Improves Prediction of Reoffending: A Naturalistic Longitudinal Comparative Study

ERIC Educational Resources Information Center

Åström, Therese; Gumpert, Clara Hellner; Andershed, Anna-Karin; Forster, Martin

2017-01-01

Purpose: This study investigated the utility of the risk assessment "Structured Assessment of Violence Risk in Youth" (SAVRY) within the social services in Stockholm County, Sweden. Method: SAVRY assessments of 56 adolescents were compared to assessments guided by another instrument (Adolescent Drug Abuse Diagnosis [ADAD]; n = 38) and…

Longitudinal Assessment of Self-Reported Recent Back Pain and Combat Deployment in the Millennium Cohort Study

DTIC Science & Technology

2016-11-15

participants who were followed for the development of back pain for an average of 3.9 years. Methods. Descriptive statistics and longitudinal...health, military personnel, occupational health, outcome assessment, statistics, survey methodology . Level of Evidence: 3 Spine 2016;41:1754–1763ack...based on the National Health and Nutrition Examination Survey.21 Statistical Analysis Descriptive and univariate analyses compared character- istics

A randomised crossover study to compare the cross-sectional and longitudinal approaches to ultrasound-guided peripheral venepuncture in a model.

PubMed

Griffiths, James; Carnegie, Amadeus; Kendall, Richard; Madan, Rajeev

2017-12-01

Ultrasound-guided peripheral intravenous access may present an alternative to central or intraosseous access in patients with difficult peripheral veins. Using venepuncture of a phantom model as a proxy, we investigated whether novice ultrasound users should adopt a cross-sectional or longitudinal approach when learning to access peripheral veins under ultrasound guidance. This result would inform the development of a structured training method for this procedure. We conducted a randomised controlled trial of 30 medical students. Subjects received 35 min of training, then attempted to aspirate 1 ml of synthetic blood from a deep vein in a training model under ultrasound guidance. Subjects attempted both the cross-sectional and longitudinal approaches. Group 1 used cross-sectional first, followed by longitudinal. Group 2 used longitudinal first, then cross-sectional. We measured the time from first puncture of the model's skin to aspiration of fluid, and the number of attempts required. Subjects also reported difficulty ratings for each approach. Paired sample t-tests were used for statistical analysis. The mean number of attempts was 1.13 using the cross-sectional approach, compared with 1.30 using the longitudinal approach (p = 0.17). Mean time to aspiration of fluid was 45.1 s using the cross-sectional approach and 52.8 s using the longitudinal approach (p = 0.43). The mean difficulty score out of 10 was 3.97 for the cross-sectional approach and 3.93 for the longitudinal approach (p = 0.95). We found no significant difference in effectiveness between the cross-sectional and longitudinal approaches to ultrasound-guided venepuncture when performed on a model. We believe that both approaches should be included when teaching ultrasound-guided peripheral vascular access. To confirm which approach would be best in clinical practice, we advocate future testing of both approaches on patients.

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

PubMed Central

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

2011-01-01

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

Longitudinal Study of Body Mass Index in Young Males and the Transition to Fatherhood

PubMed Central

Garfield, Craig F.; Duncan, Greg; Gutina, Anna; Rutsohn, Joshua; McDade, Thomas W.; Adam, Emma K.; Coley, Rebekah Levine; Chase-Lansdale, P. Lindsay

2017-01-01

Despite a growing understanding that the social determinants of health have an impact on body mass index (BMI), the role of fatherhood on young men’s BMI is understudied. This longitudinal study examines BMI in young men over time as they transition from adolescence into fatherhood in a nationally representative sample. Data from all four waves of the National Longitudinal Study of Adolescent Health supported a 20-year longitudinal analysis of 10,253 men beginning in 1994. A “fatherhood-year” data set was created and changes in BMI were examined based on fatherhood status (nonfather, nonresident father, resident father), fatherhood years, and covariates. Though age is positively associated with BMI over all years for all men, comparing nonresident and resident fathers with nonfathers reveals different trajectories based on fatherhood status. Entrance into fatherhood is associated with an increase in BMI trajectory for both nonresident and resident fathers, while nonfathers exhibit a decrease over the same period. In this longitudinal, population-based study, fatherhood and residence status play a role in men’s BMI. Designing obesity prevention interventions for young men that begin in adolescence and carry through young adulthood should target the distinctive needs of these populations, potentially improving their health outcomes. PMID:26198724

SU-F-T-478: Effect of Deconvolution in Analysis of Mega Voltage Photon Beam Profiles

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

Muthukumaran, M; Manigandan, D; Murali, V

2016-06-15

Purpose: To study and compare the penumbra of 6 MV and 15 MV photon beam profiles after deconvoluting different volume ionization chambers. Methods: 0.125cc Semi-Flex chamber, Markus Chamber and PTW Farmer chamber were used to measure the in-plane and cross-plane profiles at 5 cm depth for 6 MV and 15 MV photons. The profiles were measured for various field sizes starting from 2×2 cm till 30×30 cm. PTW TBA scan software was used for the measurements and the “deconvolution” functionality in the software was used to remove the volume averaging effect due to finite volume of the chamber along lateralmore » and longitudinal directions for all the ionization chambers. The predicted true profile was compared and the change in penumbra before and after deconvolution was studied. Results: After deconvoluting the penumbra decreased by 1 mm for field sizes ranging from 2 × 2 cm till 20 x20 cm. This is observed for along both lateral and longitudinal directions. However for field sizes from 20 × 20 till 30 ×30 cm the difference in penumbra was around 1.2 till 1.8 mm. This was observed for both 6 MV and 15 MV photon beams. The penumbra was always lesser in the deconvoluted profiles for all the ionization chambers involved in the study. The variation in difference in penumbral values were in the order of 0.1 till 0.3 mm between the deconvoluted profile along lateral and longitudinal directions for all the chambers under study. Deconvolution of the profiles along longitudinal direction for Farmer chamber was not good and is not comparable with other deconvoluted profiles. Conclusion: The results of the deconvoluted profiles for 0.125cc and Markus chamber was comparable and the deconvolution functionality can be used to overcome the volume averaging effect.« less

Neuropsychometric tests in cross sectional and longitudinal studies - a regression analysis of ADAS - cog, SKT and MMSE.

PubMed

Ihl, R; Grass-Kapanke, B; Jänner, M; Weyer, G

1999-11-01

In clinical and drug studies, different neuropsychometric tests are used. So far, no empirical data have been published to compare studies using different tests. The purpose of this study was to calculate a regression formula allowing a comparison of cross-sectional and longitudinal data from three neuropsychometric tests that are frequently used in drug studies (Alzheimer's Disease Assessment Scale, ADAS-cog; Syndrom Kurz Test, SKT; Mini Mental State Examination, MMSE). 177 patients with dementia according to ICD10 criteria were studied for the cross sectional and 61 for the longitudinal analysis. Correlations and linear regressions were calculated between tests. Significance was proven with ANOVA and t-tests using the SPSS statistical package. Significant Spearman correlations and slopes in the regression occurred in the cross sectional analysis (ADAS-cog-SKT r(s) = 0.77, slope = 0.45, SKT-ADAS-cog slope = 1.3, r2 = 0.59; ADAS-cog-MMSE r2 = 0.76, slope = -0.42, MMSE-ADAS-cog slope = -1.5, r2 = 0.64; MMSE-SKT r(s) = -0.79, slope = -0.87, SKT-MMSE slope = -0.71, r2 = 0.62; p<0.001 after Bonferroni correction; N = 177) and in the longitudinal analysis (SKT-ADAS-cog, r(s) = 0.48, slope = 0.69, ADAS-cog-SKT slope = 0.69, p<0.001, r2 = 0.32, MMSE-SKT, r(s) = 0.44, slope = -0.41, SKT-MMSE, slope = -0.55, p<0.001, r2 = 0.21). The results allow calculation of ADAS-scores when SKT scores are given, and vice versa. In longitudinal studies or in the course of the disease, scores assessed with the ADAS-cog and the SKT may now be statistically compared. In all comparisons, bottom and ceiling effects of the tests have to be taken into account.

Women with polycystic ovary syndrome demonstrate worsening markers of cardiovascular risk over the short-term despite declining hyperandrogenaemia: Results of a longitudinal study with community controls.

PubMed

Huddleston, Heather G; Quinn, Molly M; Kao, Chia-Ning; Lenhart, Nikolaus; Rosen, Mitchell P; Cedars, Marcelle I

2017-12-01

To compare age-associated changes in cardiovascular risk markers in lean and obese reproductive-aged women with polycystic ovary syndrome (PCOS) with community controls. Longitudinal study at an academic medical centre PATIENTS: Patients diagnosed with PCOS by 2004 Rotterdam criteria in a multidisciplinary clinic were systematically enrolled from 2006-2014 in a PCOS cohort study and subsequently agreed to participate in a longitudinal study. The comparison controls were from the prospective, longitudinal Ovarian Aging (OVA) study, which consists of healthy women with regular menstrual cycles recruited from 2006 to 2011. Cardiovascular risk markers and hormone parameters at baseline and follow-up. Obese and lean PCOS (n = 38) and control women (n = 296) completed two study visits. The follow-up time (3.5 ± 1.5 vs 4.0 ± 0.8 years, P = .06) and magnitude of BMI gain (+0.1 kg/m 2 /y [-0.11, 0.36] vs +0.26 [-0.18, 0.87] P = .19) did not differ between obese and lean PCOS and controls. In PCOS subjects, total testosterone decreased in both obese and lean, but the decrease was greater in obese subjects (-0.09 nmol/L per year; 95% CI: -0.16, -0.02 vs -0.04 nmol/L per year; 95%CI: -0.11, 0.03). Compared to their respective controls, obese and lean PCOS saw worsening triglyceride (TG) levels (P < .05) and HOMA-IR (P < .05) over time, but there was no difference in change in LDL, HDL, fasting glucose, C-reactive protein or ALT. In a longitudinal study, reproductive-aged women with PCOS demonstrated declines in biochemical hyperandrogenaemia over time. Despite this, PCOS subjects experienced steeper increases in cardiovascular risk factors associated with insulin resistance, including triglycerides and HOMA-IR. © 2017 John Wiley & Sons Ltd.

Study of the longitudinal space charge compensation and longitudinal instability of the ferrite inductive inserts in the Los Alamos Proton Storage Ring

NASA Astrophysics Data System (ADS)

Beltran, Chris

Future high intensity synchrotrons will have a large space charge effect. It has been demonstrated in the Proton Storage Ring (PSR) at the Los Alamos National Laboratory (LANL) that ferrite inductive inserts can be used to compensate for the longitudinal space charge effect. However, simply installing ferrite inductors in the PSR led to longitudinal instabilities that were not tolerable. It was proposed that heating the ferrite would change the material properties in such a way as to reduce the instability. This proposal was tested in the PSR, and found to be true. This dissertation investigates and describes the complex permeability of the ferrite at room temperature and at an elevated temperature. The derived complex permeability is then used to obtain an impedance at the two temperatures. The impedance is used to determine the amount of space charge compensation supplied by the inductors and predict the growth time and frequency range of the longitudinal instability. The impedance is verified by comparing the experimental growth time and frequency range of the longitudinal instability to theoretical and computer simulated growth times and frequency ranges of the longitudinal instability. Lastly, an approach to mitigating the longitudinal instability that does not involve heating the ferrite is explored.

Immigrant employment and earnings growth in Canada and the USA: evidence from longitudinal data

PubMed Central

Kaushal, Neeraj; Lu, Yao; Denier, Nicole; Wang, Julia Shu-Huah; Trejo, Stephen J.

2016-01-01

We study the short-term trajectories of employment, hours worked, and real wages of immigrants in Canada and the U.S. using nationally representative longitudinal datasets covering 1996–2008. Models with person fixed effects show that on average immigrant men in Canada do not experience any relative growth in these three outcomes compared to men born in Canada. Immigrant men in the U.S., on the other hand, experience positive annual growth in all three domains relative to U.S. born men. This difference is largely on account of low-educated immigrant men, who experience faster or longer periods of relative growth in employment and wages in the U.S. than in Canada. We further compare longitudinal and cross-sectional trajectories and find that the latter over-estimate wage growth of earlier arrivals, presumably reflecting selective return migration. PMID:28138209

The impact of different strategies to handle missing data on both precision and bias in a drug safety study: a multidatabase multinational population-based cohort study

PubMed Central

Martín-Merino, Elisa; Calderón-Larrañaga, Amaia; Hawley, Samuel; Poblador-Plou, Beatriz; Llorente-García, Ana; Petersen, Irene; Prieto-Alhambra, Daniel

2018-01-01

Background Missing data are often an issue in electronic medical records (EMRs) research. However, there are many ways that people deal with missing data in drug safety studies. Aim To compare the risk estimates resulting from different strategies for the handling of missing data in the study of venous thromboembolism (VTE) risk associated with antiosteoporotic medications (AOM). Methods New users of AOM (alendronic acid, other bisphosphonates, strontium ranelate, selective estrogen receptor modulators, teriparatide, or denosumab) aged ≥50 years during 1998–2014 were identified in two Spanish (the Base de datos para la Investigación Farmacoepidemiológica en Atención Primaria [BIFAP] and EpiChron cohort) and one UK (Clinical Practice Research Datalink [CPRD]) EMR. Hazard ratios (HRs) according to AOM (with alendronic acid as reference) were calculated adjusting for VTE risk factors, body mass index (that was missing in 61% of patients included in the three databases), and smoking (that was missing in 23% of patients) in the year of AOM therapy initiation. HRs and standard errors obtained using cross-sectional multiple imputation (MI) (reference method) were compared to complete case (CC) analysis – using only patients with complete data – and longitudinal MI – adding to the cross-sectional MI model the body mass index/smoking values as recorded in the year before and after therapy initiation. Results Overall, 422/95,057 (0.4%), 19/12,688 (0.1%), and 2,051/161,202 (1.3%) VTE cases/participants were seen in BIFAP, EpiChron, and CPRD, respectively. HRs moved from 100.00% underestimation to 40.31% overestimation in CC compared with cross-sectional MI, while longitudinal MI methods provided similar risk estimates compared with cross-sectional MI. Precision for HR improved in cross-sectional MI versus CC by up to 160.28%, while longitudinal MI improved precision (compared with cross-sectional) only minimally (up to 0.80%). Conclusion CC may substantially affect relative risk estimation in EMR-based drug safety studies, since missing data are not often completely at random. Little improvement was seen in these data in terms of power with the inclusion of longitudinal MI compared with cross-sectional MI. The strategy for handling missing data in drug safety studies can have a large impact on both risk estimates and precision.

The impact of different strategies to handle missing data on both precision and bias in a drug safety study: a multidatabase multinational population-based cohort study.

PubMed

Martín-Merino, Elisa; Calderón-Larrañaga, Amaia; Hawley, Samuel; Poblador-Plou, Beatriz; Llorente-García, Ana; Petersen, Irene; Prieto-Alhambra, Daniel

2018-01-01

Missing data are often an issue in electronic medical records (EMRs) research. However, there are many ways that people deal with missing data in drug safety studies. To compare the risk estimates resulting from different strategies for the handling of missing data in the study of venous thromboembolism (VTE) risk associated with antiosteoporotic medications (AOM). New users of AOM (alendronic acid, other bisphosphonates, strontium ranelate, selective estrogen receptor modulators, teriparatide, or denosumab) aged ≥50 years during 1998-2014 were identified in two Spanish (the Base de datos para la Investigación Farmacoepidemiológica en Atención Primaria [BIFAP] and EpiChron cohort) and one UK (Clinical Practice Research Datalink [CPRD]) EMR. Hazard ratios (HRs) according to AOM (with alendronic acid as reference) were calculated adjusting for VTE risk factors, body mass index (that was missing in 61% of patients included in the three databases), and smoking (that was missing in 23% of patients) in the year of AOM therapy initiation. HRs and standard errors obtained using cross-sectional multiple imputation (MI) (reference method) were compared to complete case (CC) analysis - using only patients with complete data - and longitudinal MI - adding to the cross-sectional MI model the body mass index/smoking values as recorded in the year before and after therapy initiation. Overall, 422/95,057 (0.4%), 19/12,688 (0.1%), and 2,051/161,202 (1.3%) VTE cases/participants were seen in BIFAP, EpiChron, and CPRD, respectively. HRs moved from 100.00% underestimation to 40.31% overestimation in CC compared with cross-sectional MI, while longitudinal MI methods provided similar risk estimates compared with cross-sectional MI. Precision for HR improved in cross-sectional MI versus CC by up to 160.28%, while longitudinal MI improved precision (compared with cross-sectional) only minimally (up to 0.80%). CC may substantially affect relative risk estimation in EMR-based drug safety studies, since missing data are not often completely at random. Little improvement was seen in these data in terms of power with the inclusion of longitudinal MI compared with cross-sectional MI. The strategy for handling missing data in drug safety studies can have a large impact on both risk estimates and precision.

Analysis of the proton longitudinal structure function from the gluon distribution function

NASA Astrophysics Data System (ADS)

Boroun, G. R.; Rezaei, B.

2012-11-01

We make a critical, next-to-leading order, study of the relationship between the longitudinal structure function F L and the gluon distribution proposed in Cooper-Sarkar et al. (Z. Phys. C 39:281, 1988; Acta Phys. Pol. B 34:2911 2003), which is frequently used to extract the gluon distribution from the proton longitudinal structure function at small x. The gluon density is obtained by expanding at particular choices of the point of expansion and compared with the hard Pomeron behavior for the gluon density. Comparisons with H1 data are made and predictions for the proposed best approach are also provided.

National Study of Student Support Services. Third-Year Longitudinal Study Results and Program Implementation Study Update.

ERIC Educational Resources Information Center

Chaney, Bradford; Muraskin, Lana; Cahalan, Margaret; Rak, Rebecca

This follow-up study, part of the National Study of Student Support Services compared the status of 2,900 disadvantaged students receiving student support services (SSS) since entering college 3 years earlier and 2,900 nonparticipating comparable students. Services offered varied among institutions but were all intended to help students stay in…

Comparing identified and statistically significant lipids and polar metabolites in 15-year old serum and dried blood spot samples for longitudinal studies: Comparing lipids and metabolites in serum and DBS samples

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

Kyle, Jennifer E.; Casey, Cameron P.; Stratton, Kelly G.

The use of dried blood spots (DBS) has many advantages over traditional plasma and serum samples such as smaller blood volume required, storage at room temperature, and ability for sampling in remote locations. However, understanding the robustness of different analytes in DBS samples is essential, especially in older samples collected for longitudinal studies. Here we analyzed DBS samples collected in 2000-2001 and stored at room temperature and compared them to matched serum samples stored at -80°C to determine if they could be effectively used as specific time points in a longitudinal study following metabolic disease. Four hundred small molecules weremore » identified in both the serum and DBS samples using gas chromatograph-mass spectrometry (GC-MS), liquid chromatography-MS (LC-MS) and LC-ion mobility spectrometry-MS (LC-IMS-MS). The identified polar metabolites overlapped well between the sample types, though only one statistically significant polar metabolite in a case-control study was conserved, indicating degradation occurs in the DBS samples affecting quantitation. Differences in the lipid identifications indicated that some oxidation occurs in the DBS samples. However, thirty-six statistically significant lipids correlated in both sample types indicating that lipid quantitation was more stable across the sample types.« less

Longitudinal Profiles of Adaptive Behavior in Fragile X Syndrome

PubMed Central

Quintin, Eve-Marie; Jo, Booil; Lightbody, Amy A.; Hazlett, Heather Cody; Piven, Joseph; Hall, Scott S.; Reiss, Allan L.

2014-01-01

OBJECTIVE: To examine longitudinally the adaptive behavior patterns in fragile X syndrome. METHOD: Caregivers of 275 children and adolescents with fragile X syndrome and 225 typically developing children and adolescents (2–18 years) were interviewed with the Vineland Adaptive Behavior Scales every 2 to 4 years as part of a prospective longitudinal study. RESULTS: Standard scores of adaptive behavior in people with fragile X syndrome are marked by a significant decline over time in all domains for males and in communication for females. Socialization skills are a relative strength as compared with the other domains for males with fragile X syndrome. Females with fragile X syndrome did not show a discernible pattern of developmental strengths and weaknesses. CONCLUSIONS: This is the first large-scale longitudinal study to show that the acquisition of adaptive behavior slows as individuals with fragile X syndrome age. It is imperative to ensure that assessments of adaptive behavior skills are part of intervention programs focusing on childhood and adolescence in this condition. PMID:25070318

[BIOMECHANICAL COMPARATIVE STUDY ON FOUR INTERNAL FIXATIONS FOR ACETABULAR FRACTURES IN QUADRILATERAL AREA].

PubMed

Wang, Lei; Wu, Xiaobo; Qi, Wei; Wang, Yongbin; He, Quanjie; Xu, Fengsong; Liu, Hongyang

2015-10-01

To compare the biomechanical difference of 4 kinds of internal fixations for acetabular fracture in quadrilateral area. The transverse fracture models were created in 16 hemipelves specimens from 8 adult males, and were randomly divided into 4 groups according to different internal fixation methods (n = 4): infrapectineal buttress reconstruction plate (group A), infrapectineal buttress locking reconstruction plate (group B), reconstruction plate combined with trans-plate quadrilateral screws (group C), and anterior reconstruction plate-lag screw (group D). Then the horizontal displacement, longitudinal displacement of fractures, and axial stiffness were measured and counted to compare the stability after continuous vertical loading. Under the same loading, the horizontal and longitudinal displacements of groups A, B, C, and D were decreased gradually; when the loading reached 1 800 N, the longitudinal displacement of group A was more than 3.00 mm, indicating the failure criterion, while the axial stiffness increased gradually. Under 200 N loading, there was no significant difference (P > 0.05) in horizontal displacement, longitudinal displacement, and axial stiffness among 4 groups. When the loading reached 600-1 800 N, significant differences were found in horizontal displacement, longitudinal displacement, and axial stiffness among 4 groups (P < 0.05) except the horizontal displacement between groups C and D (P > 0.05). For acetabular fracture in the quadrilateral area, anterior reconstruction plate-lag screw for internal fixation has highest stability, followed by reconstruction plate combined with trans-plate quadrilateral screws, and they are better than infrapectineal buttress reconstruction plate and infrapectineal buttress locking reconstruction plate.

White matter microstructural changes in adolescent anorexia nervosa including an exploratory longitudinal study.

PubMed

Vogel, Katja; Timmers, Inge; Kumar, Vinod; Nickl-Jockschat, Thomas; Bastiani, Matteo; Roebroek, Alard; Herpertz-Dahlmann, Beate; Konrad, Kerstin; Goebel, Rainer; Seitz, Jochen

2016-01-01

Anorexia nervosa (AN) often begins in adolescence, however, the understanding of the underlying pathophysiology at this developmentally important age is scarce, impeding early interventions. We used diffusion tensor imaging (DTI) to investigate microstructural white matter (WM) brain changes including an experimental longitudinal follow-up. We acquired whole brain diffusion-weighted brain scans of 22 adolescent female hospitalized patients with AN at admission and nine patients longitudinally at discharge after weight rehabilitation. Patients (10-18 years) were compared to 21 typically developing controls (TD). Tract-based spatial statistics (TBSS) were applied to compare fractional anisotropy (FA) across groups and time points. Associations between average FA values of the global WM skeleton and weight as well as illness duration parameters were analyzed by multiple linear regression. We observed increased FA in bilateral frontal, parietal and temporal areas in AN patients at admission compared to TD. Higher FA of the global WM skeleton at admission was associated with faster weight loss prior to admission. Exploratory longitudinal analysis showed this FA increase to be partially normalized after weight rehabilitation. Our findings reveal a markedly different pattern of WM microstructural changes in adolescent AN compared to most previous results in adult AN. This could signify a different susceptibility and reaction to semi-starvation in the still developing brain of adolescents or a time-dependent pathomechanism differing with extend of chronicity. Higher FA at admission in adolescents with AN could point to WM fibers being packed together more closely.

The dynamic behavior of mortar under impact-loading

NASA Astrophysics Data System (ADS)

Kawai, Nobuaki; Inoue, Kenji; Misawa, Satoshi; Tanaka, Kyoji; Hayashi, Shizuo; Kondo, Ken-Ichi; Riedel, Werner

2007-06-01

Concrete and mortar are the most fundamental structural material. Therefore, considerable interest in characterizing the dynamic behavior of them under impact-loading exists. In this study, plate impact experiments have been performed to determine the dynamic behavior of mortar. Longitudinal and lateral stresses have been directly measured by means of embedded polyvinylidene fluoride (PVDF) gauges up to 1 GPa. A 200 mm-cal. powder gun enable us to measure longitudinal and lateral stresses at several point from the impact surface, simultaneously. The shear strength under impact-loading has been obtained from measured longitudinal and lateral stresses. The longitudinal stress profile shows a two-wave structure. It is indicated that this structure is associated with the onset of pore compaction and failure of mortar by comparing with hydrocode simulations using an elastic-plastic damage model for concrete.

The Shock Behaviour of a SiO2-Li2O Transparent Glass-Ceramic Armour Material

NASA Astrophysics Data System (ADS)

Pickup, I. M.; Millett, J. C. F.; Bourne, N. K.

2004-07-01

The dynamic behaviour of a transparent glass-ceramic material, Transarm, developed by Alstom UK for the UK MoD has been studied. Plate impact experiments have been used to measure the materials Hugoniot characteristics and failure behaviour. Longitudinal stresses have been measured using embedded and back surface mounted Manganin gauges. Above a threshold stress of ca. 4 GPa, the longitudinal stress histories exhibit a significant secondary rise, prior to attaining their Hugoniot stress. Lateral stresses were also measured by embedding Manganin gauges in longitudinal cuts. Significant secondary rises in stress were observed when the applied longitudinal stress exceeded the 4 GPa threshold, indicating the presence of a failure front. The dynamic shear strength of the glass has been measured using the longitudinal and lateral data. Even though significant strength drops have been measured before and behind the failure front, the material has a high post-failure strength compared to non- crystalline glasses.

Measurements of the separated longitudinal structure function FL from hydrogen and deuterium targets at low Q2

NASA Astrophysics Data System (ADS)

Tvaskis, V.; Tvaskis, A.; Niculescu, I.; Abbott, D.; Adams, G. S.; Afanasev, A.; Ahmidouch, A.; Angelescu, T.; Arrington, J.; Asaturyan, R.; Avery, S.; Baker, O. K.; Benmouna, N.; Berman, B. L.; Biselli, A.; Blok, H. P.; Boeglin, W. U.; Bosted, P. E.; Brash, E.; Breuer, H.; Chang, G.; Chant, N.; Christy, M. E.; Connell, S. H.; Dalton, M. M.; Danagoulian, S.; Day, D.; Dodario, T.; Dunne, J. A.; Dutta, D.; El Khayari, N.; Ent, R.; Fenker, H. C.; Frolov, V. V.; Gaskell, D.; Garrow, K.; Gilman, R.; Gueye, P.; Hafidi, K.; Hinton, W.; Holt, R. J.; Horn, T.; Huber, G. M.; Jackson, H.; Jiang, X.; Jones, M. K.; Joo, K.; Kelly, J. J.; Keppel, C. E.; Kuhn, J.; Kinney, E.; Klein, A.; Kubarovsky, V.; Liang, Y.; Lolos, G.; Lung, A.; Mack, D.; Malace, S.; Markowitz, P.; Mbianda, G.; McGrath, E.; Mckee, D.; Meekins, D. G.; Mkrtchyan, H.; Napolitano, J.; Navasardyan, T.; Niculescu, G.; Nozar, M.; Ostapenko, T.; Papandreou, Z.; Potterveld, D.; Reimer, P. E.; Reinhold, J.; Roche, J.; Rock, S. E.; Schulte, E.; Segbefia, E.; Smith, C.; Smith, G. R.; Stoler, P.; Tadevosyan, V.; Tang, L.; Telfeyan, J.; Todor, L.; Ungaro, M.; Uzzle, A.; Vidakovic, S.; Villano, A.; Vulcan, W. F.; Warren, G.; Wesselmann, F.; Wojtsekhowski, B.; Wood, S. A.; Yan, C.; Zihlmann, B.

2018-04-01

Structure functions, as measured in lepton-nucleon scattering, have proven to be very useful in studying the partonic dynamics within the nucleon. However, it is experimentally difficult to separately determine the longitudinal and transverse structure functions, and consequently there are substantially less data available in particular for the longitudinal structure function. Here, we present separated structure functions for hydrogen and deuterium at low four-momentum transfer squared, Q2<1 GeV2 , and compare them with parton distribution parametrization and kT factorization approaches. While differences are found, the parametrizations generally agree with the data, even at the very low-Q2 scale of the data. The deuterium data show a smaller longitudinal structure function and a smaller ratio of longitudinal to transverse cross section, R , than the proton. This suggests either an unexpected difference in R for the proton and the neutron or a suppression of the gluonic distribution in nuclei.

Measurements of the separated longitudinal structure function F L from hydrogen and deuterium targets at low Q 2

DOE PAGES

Tvaskis, V.; Tvaskis, A.; Niculescu, I.; ...

2018-04-26

Structure functions, as measured in lepton-nucleon scattering, have proven to be very useful in studying the partonic dynamics within the nucleon. Furthermore, it is experimentally difficult to separately determine the longitudinal and transverse structure functions, and consequently there are substantially less data available in particular for the longitudinal structure function. Here, we present separated structure functions for hydrogen and deuterium at low four-momentum transfer squared, Q 2 < 1 GeV 2, and compare them with parton distribution parametrization and k T factorization approaches. While differences are found, the parametrizations generally agree with the data, even at the very low-Q 2more » scale of the data. The deuterium data show a smaller longitudinal structure function and a smaller ratio of longitudinal to transverse cross section, R, than the proton. This suggests either an unexpected difference in R for the proton and the neutron or a suppression of the gluonic distribution in nuclei.« less

Measurements of the separated longitudinal structure function F L from hydrogen and deuterium targets at low Q 2

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

Tvaskis, V.; Tvaskis, A.; Niculescu, I.

Structure functions, as measured in lepton-nucleon scattering, have proven to be very useful in studying the partonic dynamics within the nucleon. Furthermore, it is experimentally difficult to separately determine the longitudinal and transverse structure functions, and consequently there are substantially less data available in particular for the longitudinal structure function. Here, we present separated structure functions for hydrogen and deuterium at low four-momentum transfer squared, Q 2 < 1 GeV 2, and compare them with parton distribution parametrization and k T factorization approaches. While differences are found, the parametrizations generally agree with the data, even at the very low-Q 2more » scale of the data. The deuterium data show a smaller longitudinal structure function and a smaller ratio of longitudinal to transverse cross section, R, than the proton. This suggests either an unexpected difference in R for the proton and the neutron or a suppression of the gluonic distribution in nuclei.« less

Longitudinal tear of the medial meniscus posterior horn in the anterior cruciate ligament-deficient knee significantly influences anterior stability.

PubMed

Ahn, Jin Hwan; Bae, Tae Soo; Kang, Ki-Ser; Kang, Soo Yong; Lee, Sang Hak

2011-10-01

Longitudinal tears of the medial meniscus posterior horn (MMPH) are commonly associated with a chronic anterior cruciate ligament (ACL) deficiency. Many studies have demonstrated the importance of the medial meniscus in terms of limiting the amount of anterior-posterior tibial translation in response to anterior tibial loads in ACL-deficient knees. An MMPH tear in an ACL-deficient knee increases the anterior-posterior tibial translation and rotatory instability. In addition, MMPH repair will restore the tibial translation to the level before the tear. Controlled laboratory study. Ten human cadaveric knees were tested sequentially using a custom testing system under 5 conditions: intact, ACL deficient, ACL deficient with an MMPH peripheral longitudinal tear, ACL deficient with an MMPH repair, and ACL deficient with a total medial meniscectomy. The knee kinematics were measured at 0°, 15°, 30°, 60°, and 90° of flexion in response to a 134-N anterior and 200-N axial compressive tibial load. The rotatory kinematics were also measured at 15° and 30° of flexion in a combined rotatory load of 5 N·m of internal tibial torque and 10 N·m of valgus torque. Medial meniscus posterior horn longitudinal tears in ACL-deficient knees resulted in a significant increase in anterior-posterior tibial translation at all flexion angles except 90° (P < .05). An MMPH repair in an ACL-deficient knee showed a significant decrease in anterior-posterior tibial translation at all flexion angles except 60° compared with the ACL-deficient/MMPH tear state (P < .05). The total anterior-posterior translation of the ACL-deficient/MMPH repaired knee was not significantly increased compared with the ACL (only)-deficient knee but was increased compared with the ACL-intact knee (P > .05). A total medial meniscectomy in an ACL-deficient knee did not increase the anterior-posterior tibial translation significantly compared with MMPH tears in ACL-deficient knees at all flexion angles (P > .05). In a combined rotatory load, tibial rotation after MMPH tears or a total medial meniscectomy in an ACL-deficient knee were not affected significantly at all flexion angles. This study shows that an MMPH longitudinal tear in an ACL-deficient knee alters the knee kinematics, particularly the anterior-posterior tibial translation. MMPH repair significantly improved anterior-posterior tibial translation in ACL-deficient knees. These findings may help improve the treatment of patients with ACL and MMPH longitudinal tear by suggesting that the medial meniscal repairs should be performed for greater longevity when combined with an ACL reconstruction.

Mechanical stability of ordered droplet packings in microfluidic channels

NASA Astrophysics Data System (ADS)

Fleury, Jean-Baptiste; Claussen, Ohle; Herminghaus, Stephan; Brinkmann, Martin; Seemann, Ralf

2011-12-01

The mechanical response and stability of one and two-row packing of monodisperse emulsion droplets are studied in quasi 2d microchannels under longitudinal compression. Depending on the choice of parameter, a considered droplet arrangement is either transformed continuously into another packing under longitudinal compression or becomes mechanically unstable and segregates into domains of higher and lower packing fraction. Our experimental results are compared to analytical calculations for 2d-droplet arrangements with good quantitative agreement. This study also predicts important consequences for the stability of droplet arrangements in flowing systems.

Computational Investigation of Helical Traveling Wave Tube Transverse RF Field Forces

NASA Technical Reports Server (NTRS)

Kory, Carol L.; Dayton, James A.

1998-01-01

In a previous study using a fully three-dimensional (3D) helical slow-wave circuit cold- test model it was found, contrary to classical helical circuit analyses, that transverse FF electric fields have significant amplitudes compared with the longitudinal component. The RF fields obtained using this helical cold-test model have been scaled to correspond to those of an actual TWT. At the output of the tube, RF field forces reach 61%, 26% and 132% for radial, azimuthal and longitudinal components, respectively, compared to radial space charge forces indicating the importance of considering them in the design of electron beam focusing.

Comparing productive vocabulary measures from the CDI and a systematic diary study.

PubMed

Robinson, B F; Mervis, C B

1999-02-01

Expressive vocabulary data gathered during a systematic diary study of one male child's early language development are compared to data that would have resulted from longitudinal administration of the MacArthur Communicative Development Inventories spoken vocabulary checklist (CDI). Comparisons are made for (1) the number of words at monthly intervals (9; 10.15 to 2; 0.15), (2) proportion of words by lexical class (i.e. noun, predicate, closed class, 'other'), (3) growth curves. The CDI underestimates the number of words in the diary study, with the underestimation increasing as vocabulary size increases. The proportion of diary study words appearing on the CDI differed as a function of lexical class. Finally, despite the differences in vocabulary size, logistic curves proved to be the best fitting model to characterize vocabulary development as measured by both the diary study and the CDI. Implications for the longitudinal use of the CDI are discussed.

Rasch-family models are more valuable than score-based approaches for analysing longitudinal patient-reported outcomes with missing data.

PubMed

de Bock, Élodie; Hardouin, Jean-Benoit; Blanchin, Myriam; Le Neel, Tanguy; Kubis, Gildas; Bonnaud-Antignac, Angélique; Dantan, Étienne; Sébille, Véronique

2016-10-01

The objective was to compare classical test theory and Rasch-family models derived from item response theory for the analysis of longitudinal patient-reported outcomes data with possibly informative intermittent missing items. A simulation study was performed in order to assess and compare the performance of classical test theory and Rasch model in terms of bias, control of the type I error and power of the test of time effect. The type I error was controlled for classical test theory and Rasch model whether data were complete or some items were missing. Both methods were unbiased and displayed similar power with complete data. When items were missing, Rasch model remained unbiased and displayed higher power than classical test theory. Rasch model performed better than the classical test theory approach regarding the analysis of longitudinal patient-reported outcomes with possibly informative intermittent missing items mainly for power. This study highlights the interest of Rasch-based models in clinical research and epidemiology for the analysis of incomplete patient-reported outcomes data. © The Author(s) 2013.

Beyond the Cross-Sectional: Neighborhood Poverty Histories and Preterm Birth

PubMed Central

Margerison-Zilko, Claire; Jun, Jina; Marchi, Kristen; Fingar, Kathryn; Braveman, Paula

2015-01-01

Objectives. We examined associations between longitudinal neighborhood poverty trajectories and preterm birth (PTB). Methods. Using data from the Neighborhood Change Database (1970–2000) and the American Community Survey (2005–2009), we categorized longitudinal trajectories of poverty for California neighborhoods (i.e., census tracts). Birth data included 23 291 singleton California births from the Maternal and Infant Health Assessment (2003–2009). We estimated associations (adjusted for individual-level covariates) between PTB and longitudinal poverty trajectories and compared these to associations using traditional, cross-sectional measures of poverty. Results. Compared to neighborhoods with long-term low poverty, those with long-term high poverty and those that experienced increasing poverty early in the study period had 41% and 37% increased odds of PTB (95% confidence interval [CI] = 1.18, 1.69 and 1.09, 1.72, respectively). High (compared with low) cross-sectional neighborhood poverty was not associated with PTB (odds ratio = 1.08; 95% CI = 0.91, 1.28). Conclusions. Neighborhood poverty histories may contribute to an understanding of perinatal health and should be considered in future research. PMID:25880941

Beyond the cross-sectional: neighborhood poverty histories and preterm birth.

PubMed

Margerison-Zilko, Claire; Cubbin, Catherine; Jun, Jina; Marchi, Kristen; Fingar, Kathryn; Braveman, Paula

2015-06-01

We examined associations between longitudinal neighborhood poverty trajectories and preterm birth (PTB). Using data from the Neighborhood Change Database (1970-2000) and the American Community Survey (2005-2009), we categorized longitudinal trajectories of poverty for California neighborhoods (i.e., census tracts). Birth data included 23 291 singleton California births from the Maternal and Infant Health Assessment (2003-2009). We estimated associations (adjusted for individual-level covariates) between PTB and longitudinal poverty trajectories and compared these to associations using traditional, cross-sectional measures of poverty. Compared to neighborhoods with long-term low poverty, those with long-term high poverty and those that experienced increasing poverty early in the study period had 41% and 37% increased odds of PTB (95% confidence interval [CI] = 1.18, 1.69 and 1.09, 1.72, respectively). High (compared with low) cross-sectional neighborhood poverty was not associated with PTB (odds ratio = 1.08; 95% CI = 0.91, 1.28). Neighborhood poverty histories may contribute to an understanding of perinatal health and should be considered in future research.

Data-driven regions of interest for longitudinal change in frontotemporal lobar degeneration.

PubMed

Pankov, Aleksandr; Binney, Richard J; Staffaroni, Adam M; Kornak, John; Attygalle, Suneth; Schuff, Norbert; Weiner, Michael W; Kramer, Joel H; Dickerson, Bradford C; Miller, Bruce L; Rosen, Howard J

2016-01-01

Current research is investigating the potential utility of longitudinal measurement of brain structure as a marker of drug effect in clinical trials for neurodegenerative disease. Recent studies in Alzheimer's disease (AD) have shown that measurement of change in empirically derived regions of interest (ROIs) allows more reliable measurement of change over time compared with regions chosen a-priori based on known effects of AD on brain anatomy. Frontotemporal lobar degeneration (FTLD) is a devastating neurodegenerative disorder for which there are no approved treatments. The goal of this study was to identify an empirical ROI that maximizes the effect size for the annual rate of brain atrophy in FTLD compared with healthy age matched controls, and to estimate the effect size and associated power estimates for a theoretical study that would use change within this ROI as an outcome measure. Eighty six patients with FTLD were studied, including 43 who were imaged twice at 1.5 T and 43 at 3 T, along with 105 controls (37 imaged at 1.5 T and 67 at 3 T). Empirically-derived maps of change were generated separately for each field strength and included the bilateral insula, dorsolateral, medial and orbital frontal, basal ganglia and lateral and inferior temporal regions. The extent of regions included in the 3 T map was larger than that in the 1.5 T map. At both field strengths, the effect sizes for imaging were larger than for any clinical measures. At 3 T, the effect size for longitudinal change measured within the empirically derived ROI was larger than the effect sizes derived from frontal lobe, temporal lobe or whole brain ROIs. The effect size derived from the data-driven 1.5 T map was smaller than at 3 T, and was not larger than the effect size derived from a-priori ROIs. It was estimated that measurement of longitudinal change using 1.5 T MR systems requires approximately a 3-fold increase in sample size to obtain effect sizes equivalent to those seen at 3 T. While the results should be confirmed in additional datasets, these results indicate that empirically derived ROIs can reduce the number of subjects needed for a longitudinal study of drug effects in FTLD compared with a-priori ROIs. Field strength may have a significant impact on the utility of imaging for measuring longitudinal change.

Do repeated assessments of performance status improve predictions for risk of death among patients with cancer? A population-based cohort study.

PubMed

Su, Jiandong; Barbera, Lisa; Sutradhar, Rinku

2015-06-01

Prior work has utilized longitudinal information on performance status to demonstrate its association with risk of death among cancer patients; however, no study has assessed whether such longitudinal information improves the predictions for risk of death. To examine whether the use of repeated performance status assessments improve predictions for risk of death compared to using only performance status assessment at the time of cancer diagnosis. This was a population-based longitudinal study of adult outpatients who had a cancer diagnosis and had at least one assessment of performance status. To account for each patient's changing performance status over time, we implemented a Cox model with a time-varying covariate for performance status. This model was compared to a Cox model using only a time-fixed (baseline) covariate for performance status. The regression coefficients of each model were derived based on a randomly selected 60% of patients, and then, the predictive ability of each model was assessed via concordance probabilities when applied to the remaining 40% of patients. Our study consisted of 15,487 cancer patients with over 53,000 performance status assessments. The utilization of repeated performance status assessments improved predictions for risk of death compared to using only the performance status assessment taken at diagnosis. When studying the hazard of death among patients with cancer, if available, researchers should incorporate changing information on performance status scores, instead of simply baseline information on performance status. © The Author(s) 2015.

Estimating Body Composition in Adolescent Sprint Athletes: Comparison of Different Methods in a 3 Years Longitudinal Design

PubMed Central

Aerenhouts, Dirk

2015-01-01

A recommended field method to assess body composition in adolescent sprint athletes is currently lacking. Existing methods developed for non-athletic adolescents were not longitudinally validated and do not take maturation status into account. This longitudinal study compared two field methods, i.e., a Bio Impedance Analysis (BIA) and a skinfold based equation, with underwater densitometry to track body fat percentage relative to years from age at peak height velocity in adolescent sprint athletes. In this study, adolescent sprint athletes (34 girls, 35 boys) were measured every 6 months during 3 years (age at start = 14.8 ± 1.5yrs in girls and 14.7 ± 1.9yrs in boys). Body fat percentage was estimated in 3 different ways: 1) using BIA with the TANITA TBF 410; 2) using a skinfold based equation; 3) using underwater densitometry which was considered as the reference method. Height for age since birth was used to estimate age at peak height velocity. Cross-sectional analyses were performed using repeated measures ANOVA and Pearson correlations between measurement methods at each occasion. Data were analyzed longitudinally using a multilevel cross-classified model with the PROC Mixed procedure. In boys, compared to underwater densitometry, the skinfold based formula revealed comparable values for body fatness during the study period whereas BIA showed a different pattern leading to an overestimation of body fatness starting from 4 years after age at peak height velocity. In girls, both the skinfold based formula and BIA overestimated body fatness across the whole range of years from peak height velocity. The skinfold based method appears to give an acceptable estimation of body composition during growth as compared to underwater densitometry in male adolescent sprinters. In girls, caution is warranted when interpreting estimations of body fatness by both BIA and a skinfold based formula since both methods tend to give an overestimation. PMID:26317426

Association of atopic diseases and attention-deficit/hyperactivity disorder: A systematic review and meta-analyses.

PubMed

Schans, Jurjen van der; Çiçek, Rukiye; de Vries, Tjalling W; Hak, Eelko; Hoekstra, Pieter J

2017-03-01

Over the last decades, the hypothesis has been raised that an atopic response could lead to the development of attention-deficit/hyperactivity disorder (ADHD). This study systematically reviews the observational cross-sectional and longitudinal studies that assessed the association between atopic disorders including asthma, atopic eczema, allergic rhinitis, and ADHD in children and adolescents. For longitudinal studies, a weighted Mantel-Haenszel odds ratio of these associations was estimated. The majority of cross-sectional and longitudinal studies reported a statistically significant positive association. The meta-analysis of longitudinal studies revealed an overall weighted odds ratio for asthma of 1.34 (95% confidence interval [CI] 1.24-1.44), 1.32 (95% CI 1.20-1.45) for atopic eczema, and 1.52 (95% CI 1.43-1.63) for allergic rhinitis. Heterogeneity of study data was low (I 2 : 0%, p=0.46 and p=0.64, respectively) for both studies examining asthma and eczema but substantial for rhinitis studies (I 2 : 82%, p=0.004). This current systematic review provides strong evidence that ADHD is associated with atopic diseases and that individuals have a 30% to 50% greater chance of developing ADHD compared to controls. Copyright © 2017 Elsevier Ltd. All rights reserved.

Longitudinal decrease in blood oxygenation level dependent response in cerebral amyloid angiopathy.

PubMed

Switzer, Aaron R; McCreary, Cheryl; Batool, Saima; Stafford, Randall B; Frayne, Richard; Goodyear, Bradley G; Smith, Eric E

2016-01-01

Lower blood oxygenation level dependent (BOLD) signal changes in response to a visual stimulus in functional magnetic resonance imaging (fMRI) have been observed in cross-sectional studies of cerebral amyloid angiopathy (CAA), and are presumed to reflect impaired vascular reactivity. We used fMRI to detect a longitudinal change in BOLD responses to a visual stimulus in CAA, and to determine any correlations between these changes and other established biomarkers of CAA progression. Data were acquired from 22 patients diagnosed with probable CAA (using the Boston Criteria) and 16 healthy controls at baseline and one year. BOLD data were generated from the 200 most active voxels of the primary visual cortex during the fMRI visual stimulus (passively viewing an alternating checkerboard pattern). In general, BOLD amplitudes were lower at one year compared to baseline in patients with CAA (p = 0.01) but were unchanged in controls (p = 0.18). The longitudinal difference in BOLD amplitudes was significantly lower in CAA compared to controls (p < 0.001). White matter hyperintensity (WMH) volumes and number of cerebral microbleeds, both presumed to reflect CAA-mediated vascular injury, increased over time in CAA (p = 0.007 and p = 0.001, respectively). Longitudinal increases in WMH (rs = 0.04, p = 0.86) or cerebral microbleeds (rs = -0.18, p = 0.45) were not associated with the longitudinal decrease in BOLD amplitudes.

Ontogeny of modern human longitudinal body and transverse shoulder proportions.

PubMed

Frelat, Mélanie A; Coquerelle, Michael; Trinkaus, Erik

2017-03-01

Whereas variation of modern human adult body size and shape has been widely studied in the context of ecogeographical clines, little is known about the differential growth patterns of transverse and longitudinal dimensions among human populations. Our study explored the ontogenetic variation of those body proportions in modern humans. We compared results from four different approaches to study cross-sectional skeletal samples of Africans (n = 43), Amerindians (n = 69) and Europeans (n = 40) from 0 to 14 years of age. Clavicle, humerus, and femur intermetaphyseal lengths, and femoral distal metaphyseal breadth, were measured. Average ontogenetic trajectories were computed in order to compare the growth patterns of the three groups. Our findings demonstrated that the three geographical groups shared similar absolute and relative patterns of change with age for the four dimensions considered. Although interpopulation differences existed in transverse to longitudinal as well as in interlimb proportions, those differences did not seem to remain constant throughout ontogeny, similar to what has been shown for intralimb proportions. Growth rates of transverse shoulder proportions differed between populations from different regions after 10 years, whereas those for longitudinal proportions were very similar. The ontogeny of transverse shoulder proportions is more complex than what is observed for bi-iliac breadth, suggesting that transverse shoulder to limb proportions are not solely influenced by ecogeographical conditions. Our analysis demonstrates that methodologies that incorporate critical dimensions of body form could shed new light on human adaptation in both paleontological and neontological contexts. © 2016 Wiley Periodicals, Inc.

Clinical Evaluation of a Fully-automatic Segmentation Method for Longitudinal Brain Tumor Volumetry

NASA Astrophysics Data System (ADS)

Meier, Raphael; Knecht, Urspeter; Loosli, Tina; Bauer, Stefan; Slotboom, Johannes; Wiest, Roland; Reyes, Mauricio

2016-03-01

Information about the size of a tumor and its temporal evolution is needed for diagnosis as well as treatment of brain tumor patients. The aim of the study was to investigate the potential of a fully-automatic segmentation method, called BraTumIA, for longitudinal brain tumor volumetry by comparing the automatically estimated volumes with ground truth data acquired via manual segmentation. Longitudinal Magnetic Resonance (MR) Imaging data of 14 patients with newly diagnosed glioblastoma encompassing 64 MR acquisitions, ranging from preoperative up to 12 month follow-up images, was analysed. Manual segmentation was performed by two human raters. Strong correlations (R = 0.83-0.96, p < 0.001) were observed between volumetric estimates of BraTumIA and of each of the human raters for the contrast-enhancing (CET) and non-enhancing T2-hyperintense tumor compartments (NCE-T2). A quantitative analysis of the inter-rater disagreement showed that the disagreement between BraTumIA and each of the human raters was comparable to the disagreement between the human raters. In summary, BraTumIA generated volumetric trend curves of contrast-enhancing and non-enhancing T2-hyperintense tumor compartments comparable to estimates of human raters. These findings suggest the potential of automated longitudinal tumor segmentation to substitute manual volumetric follow-up of contrast-enhancing and non-enhancing T2-hyperintense tumor compartments.

Clinical Evaluation of a Fully-automatic Segmentation Method for Longitudinal Brain Tumor Volumetry.

PubMed

Meier, Raphael; Knecht, Urspeter; Loosli, Tina; Bauer, Stefan; Slotboom, Johannes; Wiest, Roland; Reyes, Mauricio

2016-03-22

Information about the size of a tumor and its temporal evolution is needed for diagnosis as well as treatment of brain tumor patients. The aim of the study was to investigate the potential of a fully-automatic segmentation method, called BraTumIA, for longitudinal brain tumor volumetry by comparing the automatically estimated volumes with ground truth data acquired via manual segmentation. Longitudinal Magnetic Resonance (MR) Imaging data of 14 patients with newly diagnosed glioblastoma encompassing 64 MR acquisitions, ranging from preoperative up to 12 month follow-up images, was analysed. Manual segmentation was performed by two human raters. Strong correlations (R = 0.83-0.96, p < 0.001) were observed between volumetric estimates of BraTumIA and of each of the human raters for the contrast-enhancing (CET) and non-enhancing T2-hyperintense tumor compartments (NCE-T2). A quantitative analysis of the inter-rater disagreement showed that the disagreement between BraTumIA and each of the human raters was comparable to the disagreement between the human raters. In summary, BraTumIA generated volumetric trend curves of contrast-enhancing and non-enhancing T2-hyperintense tumor compartments comparable to estimates of human raters. These findings suggest the potential of automated longitudinal tumor segmentation to substitute manual volumetric follow-up of contrast-enhancing and non-enhancing T2-hyperintense tumor compartments.

Clinical Evaluation of a Fully-automatic Segmentation Method for Longitudinal Brain Tumor Volumetry

PubMed Central

Meier, Raphael; Knecht, Urspeter; Loosli, Tina; Bauer, Stefan; Slotboom, Johannes; Wiest, Roland; Reyes, Mauricio

2016-01-01

Information about the size of a tumor and its temporal evolution is needed for diagnosis as well as treatment of brain tumor patients. The aim of the study was to investigate the potential of a fully-automatic segmentation method, called BraTumIA, for longitudinal brain tumor volumetry by comparing the automatically estimated volumes with ground truth data acquired via manual segmentation. Longitudinal Magnetic Resonance (MR) Imaging data of 14 patients with newly diagnosed glioblastoma encompassing 64 MR acquisitions, ranging from preoperative up to 12 month follow-up images, was analysed. Manual segmentation was performed by two human raters. Strong correlations (R = 0.83–0.96, p < 0.001) were observed between volumetric estimates of BraTumIA and of each of the human raters for the contrast-enhancing (CET) and non-enhancing T2-hyperintense tumor compartments (NCE-T2). A quantitative analysis of the inter-rater disagreement showed that the disagreement between BraTumIA and each of the human raters was comparable to the disagreement between the human raters. In summary, BraTumIA generated volumetric trend curves of contrast-enhancing and non-enhancing T2-hyperintense tumor compartments comparable to estimates of human raters. These findings suggest the potential of automated longitudinal tumor segmentation to substitute manual volumetric follow-up of contrast-enhancing and non-enhancing T2-hyperintense tumor compartments. PMID:27001047

De Qeurvian Tenosynovitis: Clinical Outcomes of Surgical Treatment with Longitudinal and Transverse Incision

PubMed Central

Abrisham, Syyed Jalil; Karbasi, Mohammad Hosein Akhavan; Zare, Jalil; Behnamfar, Zahra; Tafti, Arefah Dehghani; Shishesaz, Behzad

2011-01-01

Objectives De Quervain disease is a mechanical tenosynovitis due to inadequacy volume between abductor pollicis longus, extensor pollicis brevis and their tunnel. Treatment methods include immobilization, steroid injections, and operation. For the first time Fritz De Quervain described surgical treatment of this disease. Since then, various ways of treatment have been reported. The purpose of this study is to compare the clinical outcomes of a longitudinal incision with a transverse incision in De Quervain disease. Methods This was a randomized controlled clinical trial conducted in three hospitals in Iran, Yazd from March 2003 to September 2008. One hundred-twenty patients with De Quervain disease who did not respond to conservative treatment were operated with two different incisions. The patients were followed for three months to compare the surgical outcomes. Results During a three month follow-up, a significant difference was shown between the two methods (p=0.03). Results of surgical treatment with longitudinal incision were excellent (only 5 hypertrophic scars), but there were 13 postoperative complaints with transverse incision. Conclusion According to our findings, longitudinal incision in surgical treatment of De Quervain disease is better than transverse incision. PMID:22043391

Detecting glaucomatous change in visual fields: Analysis with an optimization framework.

PubMed

Yousefi, Siamak; Goldbaum, Michael H; Varnousfaderani, Ehsan S; Belghith, Akram; Jung, Tzyy-Ping; Medeiros, Felipe A; Zangwill, Linda M; Weinreb, Robert N; Liebmann, Jeffrey M; Girkin, Christopher A; Bowd, Christopher

2015-12-01

Detecting glaucomatous progression is an important aspect of glaucoma management. The assessment of longitudinal series of visual fields, measured using Standard Automated Perimetry (SAP), is considered the reference standard for this effort. We seek efficient techniques for determining progression from longitudinal visual fields by formulating the problem as an optimization framework, learned from a population of glaucoma data. The longitudinal data from each patient's eye were used in a convex optimization framework to find a vector that is representative of the progression direction of the sample population, as a whole. Post-hoc analysis of longitudinal visual fields across the derived vector led to optimal progression (change) detection. The proposed method was compared to recently described progression detection methods and to linear regression of instrument-defined global indices, and showed slightly higher sensitivities at the highest specificities than other methods (a clinically desirable result). The proposed approach is simpler, faster, and more efficient for detecting glaucomatous changes, compared to our previously proposed machine learning-based methods, although it provides somewhat less information. This approach has potential application in glaucoma clinics for patient monitoring and in research centers for classification of study participants. Copyright © 2015 Elsevier Inc. All rights reserved.

Analysis of baseline, average, and longitudinally measured blood pressure data using linear mixed models.

PubMed

Hossain, Ahmed; Beyene, Joseph

2014-01-01

This article compares baseline, average, and longitudinal data analysis methods for identifying genetic variants in genome-wide association study using the Genetic Analysis Workshop 18 data. We apply methods that include (a) linear mixed models with baseline measures, (b) random intercept linear mixed models with mean measures outcome, and (c) random intercept linear mixed models with longitudinal measurements. In the linear mixed models, covariates are included as fixed effects, whereas relatedness among individuals is incorporated as the variance-covariance structure of the random effect for the individuals. The overall strategy of applying linear mixed models decorrelate the data is based on Aulchenko et al.'s GRAMMAR. By analyzing systolic and diastolic blood pressure, which are used separately as outcomes, we compare the 3 methods in identifying a known genetic variant that is associated with blood pressure from chromosome 3 and simulated phenotype data. We also analyze the real phenotype data to illustrate the methods. We conclude that the linear mixed model with longitudinal measurements of diastolic blood pressure is the most accurate at identifying the known single-nucleotide polymorphism among the methods, but linear mixed models with baseline measures perform best with systolic blood pressure as the outcome.

Open surgical treatment for chronic midportion Achilles tendinopathy: faster recovery with the soleus fibres transfer technique.

PubMed

Benazzo, Francesco; Zanon, Giacomo; Klersy, Catherine; Marullo, Matteo

2016-06-01

The study aimed to compare two methods of open surgical treatment for midportion Achilles tendinopathy in sportsmen. A novel technique consisting in transferring some soleus fibres into the degenerated tendon to improve its vascularization and longitudinal tenotomies are evaluated and compared. From 2006 to 2011, fifty-two competitive and noncompetitive athletes affected by midportion Achilles tendinopathy were surgically treated and prospectively evaluated at 6 months and at a final 4-year mean follow-up. Twenty patients had longitudinal tenotomies, and thirty-two had soleus fibres transfer. Clinical outcome was evaluated by the American Orthopaedic Foot and Ankle Society (AOFAS) score and the Victorian Institute of Sports Assessment-Achilles (VISA-A) score. Time to return to walk and to run and tendon thickening were also recorded. Patients in the soleus transfer group had a higher increase in AOFAS and VISA-A score at 6 months and at the mean 4-year final follow-up (by 5.4 points, 95 % CI 2.9-7.9, p < 0.001 and by 5.7 points, 95 % CI 2.5-8.9, p = 0.001, for AOFAS and VISA, respectively). They also needed less time to return to run: 98.9 ± 17.4 days compared to 122.2 ± 26.3 days for the longitudinal tenotomies group (p = 0.0019). The soleus transfer group had a greater prevalence of tendon thickening (59.4 % compared to 30.0 % in the longitudinal tenotomies group, p = 0.037). Open surgery for midportion Achilles tendinopathy is safe and effective in medium term. Despite similar outcomes in postoperative functional scores, soleus transfer allows a faster recovery but has a higher incidence of tendon thickening. These results should suggest the use of the soleus graft technique in high-level athletes. Prospective comparative study, Level II.

Positive association between sugar consumption and dental decay prevalence independent of oral hygiene in pre-school children: a longitudinal prospective study.

PubMed

Skafida, V; Chambers, S

2017-12-29

Few studies explore how the longitudinal cumulative and combined effects of dietary habits and oral hygiene habits relate to dental decay in very young children. Using longitudinal survey data, logistic regression models were specified to predict dental decay by age 5. Predictor variables included questions on diet and oral hygiene from ages 2 to 5. Compared to mainly eating meals, children who snacked all day but had no real meals had a higher chance of dental decay (odds ratios (OR) = 2.32). There was an incremental association between a decreasing frequency of toothbrushing at age 2 and higher chances of dental decay at age 5 (OR range from 1.39 to 2.17). Among children eating sweets or chocolate more frequently (once/day or more), toothbrushing more often (once/day; twice/day or more) reduced the chance of decay (OR of 2.11-2.26 compared to OR 3.60 for the least frequent brushing group). Compared to mothers in managerial and professional occupations, those who had never worked had children with a much higher chance of decay (OR = 3.47). This study has shown that toothbrushing can only in part attenuate the association between snacking and long term sugar consumption on dental decay outcomes in children under 5. © The Author(s) 2017. Published by Oxford University Press on behalf of Faculty of Public Health.

Health and aging: development of the Irish Longitudinal Study on Ageing health assessment.

PubMed

Cronin, Hilary; O'Regan, Clare; Finucane, Ciaran; Kearney, Patricia; Kenny, Rose Anne

2013-05-01

To assist researchers planning studies similar to The Irish Longitudinal Study on Ageing (TILDA), concerning the development of the health assessment component, to promote use of the archived data set, to inform researchers of the methods employed, and to complement the accompanying article on normative values. Prospective, longitudinal study of older adults. Republic of Ireland. Eight thousand five hundred four community-dwelling adults who participated in wave 1 of the TILDA study. The main areas of focus for the TILDA health assessments are neurocardiovascular instability, locomotion, and vision. The article describes the scientific rationale for the choice of assessments and seeks to determine the potential advantages of incorporating novel biomeasures and technologies in population-based studies to advance understanding of aging-related disorders. The detailed description of the physical measures will facilitate cross-national comparative research and put into context the normative values outlined in the subsequent article. © 2013, Copyright the Authors Journal compilation © 2013, The American Geriatrics Society.

Ultrasound speckle tracking for radial, longitudinal and circumferential strain estimation of the carotid artery--an in vitro validation via sonomicrometry using clinical and high-frequency ultrasound.

PubMed

Larsson, Matilda; Heyde, Brecht; Kremer, Florence; Brodin, Lars-Åke; D'hooge, Jan

2015-02-01

Ultrasound speckle tracking for carotid strain assessment has in the past decade gained interest in studies of arterial stiffness and cardiovascular diseases. The aim of this study was to validate and directly contrast carotid strain assessment by speckle tracking applied on clinical and high-frequency ultrasound images in vitro. Four polyvinyl alcohol phantoms mimicking the carotid artery were constructed with different mechanical properties and connected to a pump generating carotid flow profiles. Gray-scale ultrasound long- and short-axis images of the phantoms were obtained using a standard clinical ultrasound system, Vivid 7 (GE Healthcare, Horten, Norway) and a high-frequency ultrasound system, Vevo 2100 (FUJIFILM, VisualSonics, Toronto, Canada) with linear-array transducers (12L/MS250). Radial, longitudinal and circumferential strains were estimated using an in-house speckle tracking algorithm and compared with reference strain acquired by sonomicrometry. Overall, the estimated strain corresponded well with the reference strain. The correlation between estimated peak strain in clinical ultrasound images and reference strain was 0.91 (p<0.001) for radial strain, 0.73 (p<0.001) for longitudinal strain and 0.90 (p<0.001) for circumferential strain and for high-frequency ultrasound images 0.95 (p<0.001) for radial strain, 0.93 (p<0.001) for longitudinal strain and 0.90 (p<0.001) for circumferential strain. A significant larger bias and root mean square error was found for circumferential strain estimation on clinical ultrasound images compared to high frequency ultrasound images, but no significant difference in bias and root mean square error was found for radial and longitudinal strain when comparing estimation on clinical and high-frequency ultrasound images. The agreement between sonomicrometry and speckle tracking demonstrates that carotid strain assessment by ultrasound speckle tracking is feasible. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

Reliabilities of Intraindividual Variability Indicators with Autocorrelated Longitudinal Data: Implications for Longitudinal Study Designs.

PubMed

Du, Han; Wang, Lijuan

2018-04-23

Intraindividual variability can be measured by the intraindividual standard deviation ([Formula: see text]), intraindividual variance ([Formula: see text]), estimated hth-order autocorrelation coefficient ([Formula: see text]), and mean square successive difference ([Formula: see text]). Unresolved issues exist in the research on reliabilities of intraindividual variability indicators: (1) previous research only studied conditions with 0 autocorrelations in the longitudinal responses; (2) the reliabilities of [Formula: see text] and [Formula: see text] have not been studied. The current study investigates reliabilities of [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], and the intraindividual mean, with autocorrelated longitudinal data. Reliability estimates of the indicators were obtained through Monte Carlo simulations. The impact of influential factors on reliabilities of the intraindividual variability indicators is summarized, and the reliabilities are compared across the indicators. Generally, all the studied indicators of intraindividual variability were more reliable with a more reliable measurement scale and more assessments. The reliabilities of [Formula: see text] were generally lower than those of [Formula: see text] and [Formula: see text], the reliabilities of [Formula: see text] were usually between those of [Formula: see text] and [Formula: see text] unless the scale reliability was large and/or the interindividual standard deviation in autocorrelation coefficients was large, and the reliabilities of the intraindividual mean were generally the highest. An R function is provided for planning longitudinal studies to ensure sufficient reliabilities of the intraindividual indicators are achieved.

Meta-Analysis of Effect Sizes Reported at Multiple Time Points Using General Linear Mixed Model.

PubMed

Musekiwa, Alfred; Manda, Samuel O M; Mwambi, Henry G; Chen, Ding-Geng

2016-01-01

Meta-analysis of longitudinal studies combines effect sizes measured at pre-determined time points. The most common approach involves performing separate univariate meta-analyses at individual time points. This simplistic approach ignores dependence between longitudinal effect sizes, which might result in less precise parameter estimates. In this paper, we show how to conduct a meta-analysis of longitudinal effect sizes where we contrast different covariance structures for dependence between effect sizes, both within and between studies. We propose new combinations of covariance structures for the dependence between effect size and utilize a practical example involving meta-analysis of 17 trials comparing postoperative treatments for a type of cancer, where survival is measured at 6, 12, 18 and 24 months post randomization. Although the results from this particular data set show the benefit of accounting for within-study serial correlation between effect sizes, simulations are required to confirm these results.

Outcomes of Left Ventricular Function According to Treatment Response for a Patent Ductus Arteriosus in Preterm Infants.

PubMed

Kang, Soo Jung; Cho, Young Sun; Hwang, Seo Jung; Kim, Hyo Jin

2017-12-01

To evaluate the outcomes of left ventricular (LV) function according to treatment response for a hemodynamically significant patent ductus arteriosus (hsPDA) in preterm infants. Echocardiograms of 21 preterm infants born at gestational age < 31 weeks obtained at term-equivalent age were retrospectively studied. Among preterm infants with a hsPDA, 9 underwent ligation after failure of pharmacological closure (ligation group) and 6 experienced successful pharmacological closure (medication group). Six preterm infants without hsPDA (no-hsPDA group) were studied as controls. LV peak longitudinal systolic strain (ε) of each infant was retrospectively obtained from echocardiograms using velocity vector imaging, along with neonatal outcomes. Pharmacological closures were attempted at postnatal day 2-3. In the ligation group, the median postnatal age at ligation was 20 days. In the ligation group, LV peak longitudinal systolic ε was significantly decreased at term-equivalent age compared to the other groups. Between the medication and no-hsPDA groups, LV peak longitudinal systolic ε did not differ significantly. Among the neonatal outcomes, infants who experienced necrotizing enterocolitis (NEC) showed significantly decreased LV peak longitudinal systolic ε compared to the infants who did not experience NEC . We speculate that in preterm infants with an hsPDA, in cases of medical treatment failure, early PDA ligation at less than 20 days of postnatal age would be beneficial for preserving LV systolic function.

Influence of mother-daughter attachment on substance use: a longitudinal study of a Latina community-based sample.

PubMed

De La Rosa, Mario; Huang, Hui; Rojas, Patria; Dillon, Frank R; Lopez-Quintero, Catalina; Li, Tan; Ravelo, Gira J

2015-03-01

Advancing our initial, cross-sectional study, which showed that adult Latinas' mother-daughter attachment relates to their substance use, the current, longitudinal study tests whether mother and daughter attachment scores at baseline predict their substance use over time. We analyzed data from a convenience sample of 133 Latina adult mothers (mean age = 52 years, SD = 10) and 133 Latina adult daughters (mean age = 27, SD = 9) at baseline and at 5-year and 6-year follow-ups after baseline (attrition rate = 16%). Multilevel longitudinal modeling was used to examine the effect of mother-daughter attachment at baseline on their substance use over time. Each unit of increase in the attachment score at baseline is associated with a 0.28 drink decrease in monthly alcohol use (p < .05) and a lower likelihood of being a heavy alcohol or other drug user [exp(β) = 0.97, p < .01] compared with average attachment score at baseline (M = 91.52, SD = 18.00). Time and older age at baseline are associated with decreased substance use. Being born outside the United States is associated with decreased risk of heavy alcohol or other drug use. Being a mother is associated with increased substance use. The findings of this longitudinal study on adult Latinas indicate that mother-daughter attachment has long-lasting effects on substance use trajectories among adult Latinas. Future research should focus on (a) investigating social and cultural factors mediating this relationship and (b) greater substance use among Latina mothers compared with daughters.

A longitudinal study of occlusal caries in Newark New Jersey school children: relationship between initial dental finding and the development of new lesions

PubMed Central

Markowitz, Kenneth; Fairlie, Karen; Ferrandiz, Javier; Nasri-Heir, Cibele

2012-01-01

Objective Dental caries is a significant public health problem especially amongst children from low-income backgrounds. This longitudinal study examined the development of new occlusal caries in 227 Newark, NJ children ages 10–18. The role of previous caries experience and the presence of occlusal white and dark lesions in predicting the development of new lesions were examined. Design At each visit, the patient’s teeth were given a visual-tactile examination and the subject’s decayed; missing and filled (DMFS) score was determined. Next, molars lacking probeable caries or restorations were examined using transillumination for occlusal white and dark spots. This examination was repeated periodically. A Cox proportional hazard was used to analyze data concerning the development of new occusal caries in molars. Results The longitudinal data indicates that patients who were caries free at visit-1 developed significantly fewer occlusal caries during the longitudinal study. The hazard ratio for subjects who had first-visit caries was 2.27 compared to caries free subjects. Intact molars with occlusal white or dark lesions had caries hazard ratios of 0.78 and 1.49 respectively, compared to molars lacking initial color changes. Conclusion Having a prior caries history places the subject at increased risk of developing future caries. Teeth with dark lesions but not white lesions are at significantly increased risk for developing decay. White lesions may represent remineralizing or slowly progressing lesions. The results of this study can help identify patients and tooth surfaces at risk for future occlusal decay. PMID:22841633

Influence of Mother–Daughter Attachment on Substance Use: A Longitudinal Study of a Latina Community-Based Sample

PubMed Central

De La Rosa, Mario; Huang, Hui; Rojas, Patria; Dillon, Frank R.; Lopez-Quintero, Catalina; Li, Tan; Ravelo, Gira J.

2015-01-01

Objective: Advancing our initial, cross-sectional study, which showed that adult Latinas’ mother–daughter attachment relates to their substance use, the current, longitudinal study tests whether mother and daughter attachment scores at baseline predict their substance use over time. Method: We analyzed data from a convenience sample of 133 Latina adult mothers (mean age = 52 years, SD = 10) and 133 Latina adult daughters (mean age = 27, SD = 9) at baseline and at 5-year and 6-year follow-ups after baseline (attrition rate = 16%). Multilevel longitudinal modeling was used to examine the effect of mother–daughter attachment at baseline on their substance use over time. Results: Each unit of increase in the attachment score at baseline is associated with a 0.28 drink decrease in monthly alcohol use (p < .05) and a lower likelihood of being a heavy alcohol or other drug user [exp(β) = 0.97, p < .01] compared with average attachment score at baseline (M = 91.52, SD = 18.00). Time and older age at baseline are associated with decreased substance use. Being born outside the United States is associated with decreased risk of heavy alcohol or other drug use. Being a mother is associated with increased substance use. Conclusions: The findings of this longitudinal study on adult Latinas indicate that mother–daughter attachment has long-lasting effects on substance use trajectories among adult Latinas. Future research should focus on (a) investigating social and cultural factors mediating this relationship and (b) greater substance use among Latina mothers compared with daughters. PMID:25785806

Longitudinal structure function from logarithmic slopes of F2 at low x

NASA Astrophysics Data System (ADS)

Boroun, G. R.

2018-01-01

Using Laplace transform techniques, I calculate the longitudinal structure function FL(x ,Q2) from the scaling violations of the proton structure function F2(x ,Q2) and make a critical study of this relationship between the structure functions at leading order (LO) up to next-to-next-to leading order (NNLO) analysis at small x . Furthermore, I consider heavy quark contributions to the relation between the structure functions, which leads to compact formula for Nf=3 +Heavy . The nonlinear corrections to the longitudinal structure function at LO up to NNLO analysis are shown in the Nf=4 (light quark flavor) based on the nonlinear corrections at R =2 and R =4 GeV-1 . The results are compared with experimental data of the longitudinal proton structure function FL in the range of 6.5 ≤Q2≤800 GeV2 .

Integrating Prospective Longitudinal Data: Modeling Personality and Health in the Terman Life Cycle and Hawaii Longitudinal Studies

PubMed Central

Kern, Margaret L.; Hampson, Sarah E.; Goldberg, Lewis R.; Friedman, Howard S.

2013-01-01

The present study used a collaborative framework to integrate two long-term prospective studies: the Terman Life Cycle Study and the Hawaii Personality and Health Longitudinal Study. Using a five-factor personality-trait framework, teacher assessments of child personality were rationally and empirically aligned to establish similar factor structures across samples. Comparable items related to adult self-rated health, education, and alcohol use were harmonized, and data were pooled on harmonized items. A structural model was estimated, allowing paths to differ by sample. Harmonized child personality factors were then used to examine markers of physiological dysfunction in the Hawaii sample and mortality risk in the Terman sample. Harmonized conscientiousness predicted less physiological dysfunction in the Hawaii sample and lower mortality risk in the Terman sample. These results illustrate how collaborative, integrative work with multiple samples offers the exciting possibility that samples from different cohorts and ages can be linked together to directly test lifespan theories of personality and health. PMID:23231689

Longitudinal Discriminant Analysis of Hemoglobin Level for Predicting Preeclampsia

PubMed Central

Nasiri, Malihe; Faghihzadeh, Soghrat; Alavi Majd, Hamid; Zayeri, Farid; Kariman, Noorosadat; Safavi Ardebili, Nastaran

2015-01-01

Background: Preeclampsia is one of the most serious complications during pregnancy with important effects on health of mother and fetus that causes maternal and fetal morbidity and mortality. This study was performed to evaluate whether high levels of hemoglobin may increase the risk of preeclampsia. Objectives: The present study aimed to predict preeclampsia by the hemoglobin profiles through longitudinal discriminant analysis and comparing the error rate of discrimination in longitudinal and cross sectional data. Patients and Methods: In a prospective cohort study from October 2010 to July 2011, 650 pregnant women referred to the prenatal clinic of Milad Hospital in Tehran were evaluated in 3 stages. The hemoglobin level of each woman was measured in the first, second, and third trimester of pregnancy by an expert technician. The subjects were followed up to delivery and preeclampsia was the main outcome under study. The covariance pattern and linear-mixed effects models are common methods that were applied for discriminant analysis of longitudinal data. Also Student t, Mann-Whitney U, and chi-square tests were used for comparing the demographic and clinical characteristics between two groups. Statistical analyses were performed using the SAS software version 9.1. Results: The prevalence rate of preeclampsia was 7.2% (47 women). The women with preeclampsia had a higher mean of hemoglobin values and the difference was 0.46 g/dL (P = 0.003). Also the mean of hemoglobin in the first trimester was higher than that of the second trimester, and was lower than that of the third trimester and the differences were significant (P = 0.015 and P < 0.001, respectively). The sensitivity for longitudinal data and cross-sectional data in three trimesters was 90%, 67%, 72%, and 54% and the specificity was 88%, 55%, 63%, and 50%, respectively. Conclusions: The levels of hemoglobin can be used to predict preeclampsia and monitoring the pregnant women and its regular measure in 3 trimesters help us to identify women at risk for preeclampsia. PMID:26019901

Sample size determination for mediation analysis of longitudinal data.

PubMed

Pan, Haitao; Liu, Suyu; Miao, Danmin; Yuan, Ying

2018-03-27

Sample size planning for longitudinal data is crucial when designing mediation studies because sufficient statistical power is not only required in grant applications and peer-reviewed publications, but is essential to reliable research results. However, sample size determination is not straightforward for mediation analysis of longitudinal design. To facilitate planning the sample size for longitudinal mediation studies with a multilevel mediation model, this article provides the sample size required to achieve 80% power by simulations under various sizes of the mediation effect, within-subject correlations and numbers of repeated measures. The sample size calculation is based on three commonly used mediation tests: Sobel's method, distribution of product method and the bootstrap method. Among the three methods of testing the mediation effects, Sobel's method required the largest sample size to achieve 80% power. Bootstrapping and the distribution of the product method performed similarly and were more powerful than Sobel's method, as reflected by the relatively smaller sample sizes. For all three methods, the sample size required to achieve 80% power depended on the value of the ICC (i.e., within-subject correlation). A larger value of ICC typically required a larger sample size to achieve 80% power. Simulation results also illustrated the advantage of the longitudinal study design. The sample size tables for most encountered scenarios in practice have also been published for convenient use. Extensive simulations study showed that the distribution of the product method and bootstrapping method have superior performance to the Sobel's method, but the product method was recommended to use in practice in terms of less computation time load compared to the bootstrapping method. A R package has been developed for the product method of sample size determination in mediation longitudinal study design.

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

PubMed Central

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

2013-01-01

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

A longitudinal model for functional connectivity networks using resting-state fMRI.

PubMed

Hart, Brian; Cribben, Ivor; Fiecas, Mark

2018-06-04

Many neuroimaging studies collect functional magnetic resonance imaging (fMRI) data in a longitudinal manner. However, the current fMRI literature lacks a general framework for analyzing functional connectivity (FC) networks in fMRI data obtained from a longitudinal study. In this work, we build a novel longitudinal FC model using a variance components approach. First, for all subjects' visits, we account for the autocorrelation inherent in the fMRI time series data using a non-parametric technique. Second, we use a generalized least squares approach to estimate 1) the within-subject variance component shared across the population, 2) the baseline FC strength, and 3) the FC's longitudinal trend. Our novel method for longitudinal FC networks seeks to account for the within-subject dependence across multiple visits, the variability due to the subjects being sampled from a population, and the autocorrelation present in fMRI time series data, while restricting the number of parameters in order to make the method computationally feasible and stable. We develop a permutation testing procedure to draw valid inference on group differences in the baseline FC network and change in FC over longitudinal time between a set of patients and a comparable set of controls. To examine performance, we run a series of simulations and apply the model to longitudinal fMRI data collected from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database. Overall, we found no difference in the global FC network between Alzheimer's disease patients and healthy controls, but did find differing local aging patterns in the FC between the left hippocampus and the posterior cingulate cortex. Copyright © 2018 Elsevier Inc. All rights reserved.

Effect of therapeutic insoles on the medial longitudinal arch in patients with flatfoot deformity: a three-dimensional loading computed tomography study.

PubMed

Kido, Masamitsu; Ikoma, Kazuya; Hara, Yusuke; Imai, Kan; Maki, Masahiro; Ikeda, Takumi; Fujiwara, Hiroyoshi; Tokunaga, Daisaku; Inoue, Nozomu; Kubo, Toshikazu

2014-12-01

Insoles are frequently used in orthotic therapy as the standard conservative treatment for symptomatic flatfoot deformity to rebuild the arch and stabilize the foot. However, the effectiveness of therapeutic insoles remains unclear. In this study, we assessed the effectiveness of therapeutic insoles for flatfoot deformity using subject-based three-dimensional (3D) computed tomography (CT) models by evaluating the load responses of the bones in the medial longitudinal arch in vivo in 3D. We studied eight individuals (16 feet) with mild flatfoot deformity. CT scans were performed on both feet under non-loaded and full-body-loaded conditions, first with accessory insoles and then with therapeutic insoles under the same conditions. Three-dimensional CT models were constructed for the tibia and the tarsal and metatarsal bones of the medial longitudinal arch (i.e., first metatarsal bone, cuneiforms, navicular, talus, and calcaneus). The rotational angles between the tarsal bones were calculated under loading with accessory insoles or therapeutic insoles and compared. Compared with the accessory insoles, the therapeutic insoles significantly suppressed the eversion of the talocalcaneal joint. This is the first study to precisely verify the usefulness of therapeutic insoles (arch support and inner wedges) in vivo. Copyright © 2014 Elsevier Ltd. All rights reserved.

Evidence of Big-Five personality changes following acquired brain injury from a prospective longitudinal investigation.

PubMed

Leonhardt, Anne; Schmukle, Stefan C; Exner, Cornelia

2016-03-01

Many studies using different assessment methods have reported personality changes after acquired brain injury (ABI). However, to our knowledge, no prospective study has yet been conducted to examine whether previous cross-sectional and retrospective results can be replicated in a longitudinal prospective design. Further, because clinical control groups were only rarely used, it remains debatable if the personality changes found are unique to patients with ABI or if they also affect patients with other disabilities. This study examined personality change in 114 participants with different kinds of ABI, 1321 matched controls (general control, GC), and 746 matched participants with restrictive impairments other than brain injury (clinical control, CC) in a prospective longitudinal design using data from the panel survey Household, Income and Labour Dynamics in Australia (HILDA). Participants with ABI showed significantly larger declines in Extraversion and Conscientiousness compared with the GC group. When the ABI participants were compared with the CC group, only the difference in Conscientiousness remained significant. Our prospective data corroborate evidence from previous cross-sectional studies that patients with ABI experience larger declines in Extraversion and Conscientiousness than the general population. Whereas the effect on Conscientiousness was unique to patients with ABI, the decline in Extraversion was also observed in participants with other impairments. Copyright © 2016 Elsevier Inc. All rights reserved.

Confronting Crisis. A Comparative Study of Household Responses to Poverty and Vulnerability in Four Poor Urban Communities. Environmentally Sustainable Development Studies and Monographs Series No. 8.

ERIC Educational Resources Information Center

Moser, Caroline O. N.

This volume presents the main findings of a comparative study of four poor urban communities in countries experiencing economic difficulties during the late 1980s: Chawama (Zambia), Cisne Dos (Ecuador), Commonwealth (the Philippines), and Angyalfold (Hungary). The study extended a longitudinal community panel study begun in Ecuador by using a…

Comparing Service Use of Early Head Start Families of Children with and without Disabilities

ERIC Educational Resources Information Center

Zajicek-Farber, Michaela L.; Wall, Shavaun M.; Kisker, Ellen E.; Luze, Gayle J.; Summers, Jean Ann

2011-01-01

The current study compared patterns of service utilization reported by Early Head Start (EHS) families of children with and without disabilities by secondary analysis of data from the longitudinal investigation of the effectiveness of EHS. Findings reveal comparable positive trends for both groups of families for receipt of services corresponding…

Longitudinal analysis of progression in glaucoma using spectral-domain optical coherence tomography.

PubMed

Wessel, Julia M; Horn, Folkert K; Tornow, Ralf P; Schmid, Matthias; Mardin, Christian Y; Kruse, Friedrich E; Juenemann, Anselm G; Laemmer, Robert

2013-05-01

To compare the longitudinal loss of RNFL thickness measurements by SD-OCT in healthy individuals and glaucoma patients with or without progression concerning optic disc morphology. A total of 62 eyes, comprising 38 glaucomatous eyes with open angle glaucoma and 24 healthy controls, were included in the study (Erlangen Glaucoma Registry, NTC00494923). All patients were investigated annually over a period of 3 years by Spectralis SD-OCT measuring peripapillary RNFL thickness. By masked comparative analysis of photographs, the eyes were classified into nonprogressive and progressive glaucoma cases. Longitudinal loss of RNFL thickness was compared with morphological changes of optic disc morphology. Mixed model analysis of annual OCT scans revealed an estimated annual decrease of the RNFL thickness by 2.12 μm in glaucoma eyes with progression, whereas glaucoma eyes without progression in optic disc morphology lost 1.18 μm per year in RNFL thickness (P = 0.002). The rate of change in healthy eyes was 0.60 μm and thereby also significantly lower than in glaucoma eyes with progression (P < 0.001). The intrasession variability of three successive measurements without head repositioning was 1.5 ± 0.7 μm. The loss of mean RNFL thickness exceeded the intrasession variability in 60% of nonprogressive eyes, and in 85% of progressive eyes after 3 years. LONGITUDINAL MEASUREMENTS OF RNFL THICKNESS USING SD-OCT SHOW A MORE PRONOUNCED REDUCTION OF RNFL THICKNESS IN PATIENTS WITH PROGRESSION COMPARED WITH PATIENTS WITHOUT PROGRESSION IN GLAUCOMATOUS OPTIC DISC CHANGES. (www.clinicaltrials.gov number, NTC00494923.).

White matter microstructural changes in adolescent anorexia nervosa including an exploratory longitudinal study

PubMed Central

Vogel, Katja; Timmers, Inge; Kumar, Vinod; Nickl-Jockschat, Thomas; Bastiani, Matteo; Roebroek, Alard; Herpertz-Dahlmann, Beate; Konrad, Kerstin; Goebel, Rainer; Seitz, Jochen

2016-01-01

Background Anorexia nervosa (AN) often begins in adolescence, however, the understanding of the underlying pathophysiology at this developmentally important age is scarce, impeding early interventions. We used diffusion tensor imaging (DTI) to investigate microstructural white matter (WM) brain changes including an experimental longitudinal follow-up. Methods We acquired whole brain diffusion-weighted brain scans of 22 adolescent female hospitalized patients with AN at admission and nine patients longitudinally at discharge after weight rehabilitation. Patients (10–18 years) were compared to 21 typically developing controls (TD). Tract-based spatial statistics (TBSS) were applied to compare fractional anisotropy (FA) across groups and time points. Associations between average FA values of the global WM skeleton and weight as well as illness duration parameters were analyzed by multiple linear regression. Results We observed increased FA in bilateral frontal, parietal and temporal areas in AN patients at admission compared to TD. Higher FA of the global WM skeleton at admission was associated with faster weight loss prior to admission. Exploratory longitudinal analysis showed this FA increase to be partially normalized after weight rehabilitation. Conclusions Our findings reveal a markedly different pattern of WM microstructural changes in adolescent AN compared to most previous results in adult AN. This could signify a different susceptibility and reaction to semi-starvation in the still developing brain of adolescents or a time-dependent pathomechanism differing with extend of chronicity. Higher FA at admission in adolescents with AN could point to WM fibers being packed together more closely. PMID:27182488

The Effects of the Green House Nursing Home Model on ADL Function Trajectory: A Retrospective Longitudinal Study

PubMed Central

YOON, Ju Young; BROWN, Roger L.; BOWERS, Barbara J.; SHARKEY, Siobhan S.; HORN, Susan D.

2015-01-01

Background Growing attention in the past few decades has focused on improving care quality and quality of life for nursing home residents. Many traditional nursing homes have attempted to transform themselves to become more homelike emphasizing individualized care. This trend is referred to as nursing home culture change in the U.S. A promising culture change nursing home model, the Green House (GH) nursing home model, has shown positive psychological outcomes. However, little is known about whether the GH nursing home model has positive effects on physical function compared to traditional nursing homes. Objectives To examine the longitudinal effects of the GH nursing home model by comparing change patterns of ADL function over time between GH home residents and traditional nursing home residents. Design A retrospective longitudinal study. Settings Four GH organizations (nine GH units and four traditional units). Participants A total of 242 residents (93 GH residents and 149 traditional home residents) who had stayed in the nursing home at least six months from admission. Methods The outcome was ADL function, and the main independent variable was the facility type in which the resident stayed: a GH or traditional unit. Age, gender, comorbidity score, cognitive function, and depressive symptoms at baseline were controlled. All of these measures were from a minimum dataset. Growth curve modeling and growth mixture modeling were employed in this study for longitudinal analyses. Results The mean ADL function showed deterioration over time, and the rates of deterioration between GH and traditional home residents were not different over time. Four different ADL function trajectories were identified for 18 months, but there was no statistical difference in the likelihood of being in one of the four trajectory classes between the two groups. Conclusions Although GH nursing homes are considered to represent an innovative model changing the nursing home environment into more person-centered, this study did not demonstrate significant differences in ADL function changes for residents in the GH nursing homes compared to traditional nursing homes. Given that the GH model continues to evolve as it is being implemented and variations within and across GH homes are identified, large-scale longitudinal studies are needed to provide further relevant information on the effects of the GH model. PMID:26260709

Quantification of regional nonuniformity and paradoxical intramural mechanics in hypertrophic cardiomyopathy by high frame rate ultrasound myocardial strain mapping.

PubMed

Sengupta, Partho P; Mehta, Vimal; Arora, Ramesh; Mohan, Jagdish C; Khandheria, Bijoy K

2005-07-01

This study tested the hypothesis that linear mapping of regional myocardial strain comprehensively assesses variations in regional myocardial function in hypertrophic cardiomyopathy. Hypertrophic cardiomyopathy is characterized by disorganized myocardial architecture that results in spatial and temporal nonuniformity of regional function. Left ventricular deformation was quantified in 20 patients with hypertrophic cardiomyopathy and compared with 25 age- and sex-matched control subjects. Abnormalities in subendocardial strain ranged from reduced longitudinal shortening to paradoxical systolic lengthening and delayed regional longitudinal contractions that were often located in small subsegmental areas. These variations were underestimated significantly by arbitrary measurements compared with linear mapping, in which a region of interest was moved across the longitudinal length of left ventricle (difference of peak and least strain, 10.7% +/- 5.1% vs 17% +/- 5.5%; P < .001). Echocardiographic assessment of variations in regional strain requires careful mapping and may be inappropriately assessed if left ventricular segments are sampled at arbitrary focal locations.

A comparison between the clinical significance and growth mixture modelling early change methods at predicting negative outcomes.

PubMed

Flood, Nicola; Page, Andrew; Hooke, Geoff

2018-05-03

Routine outcome monitoring benefits treatment by identifying potential no change and deterioration. The present study compared two methods of identifying early change and their ability to predict negative outcomes on self-report symptom and wellbeing measures. 1467 voluntary day patients participated in a 10-day group Cognitive Behaviour Therapy (CBT) program and completed the symptom and wellbeing measures daily. Early change, as defined by (a) the clinical significance method and (b) longitudinal modelling, was compared on each measure. Early change, as defined by the simpler clinical significance method, was superior at predicting negative outcomes than longitudinal modelling. The longitudinal modelling method failed to detect a group of deteriorated patients, and agreement between the early change methods and the final unchanged outcome was higher for the clinical significance method. Therapists could use the clinical significance early change method during treatment to alert them of patients at risk for negative outcomes, which in turn could allow therapists to prevent those negative outcomes from occurring.

Importance of cervical length in dysmenorrhoea aetiology.

PubMed

Zebitay, Ali G; Verit, Fatma F; Sakar, M Nafi; Keskin, Seda; Cetin, Orkun; Ulusoy, A Ibrahim

2016-05-01

The objective of this prospective case-control study was to determine whether uterine corpus and cervical length measurements have a role in dysmenorrhoea aetiology in virgins. Patients with severe primary dysmenorrhoea with visual analog scale scores of ≥7 composed the dysmenorrhoea group (n = 51), while the control group (n = 51) was of women with painless menstrual cycles or with mild pain. Longitudinal and transverse axes of the uterine cervix and uterine corpus were measured. Correlation between severity of dysmenorrhoea and uterine cervix and corpus axes was calculated. Longitudinal and transverse axes of uterine cervix as well as uterine cervix volume were significantly higher in the dysmenorrhoea group compared to the controls. There was a significant positive correlation between severity of dysmenorrhoea and the length of cervical longitudinal and transverse axes and uterine cervical volume. Our findings reveal longer cervical length and greater cervical volume in young virgin patients with dysmenorrhoea and severe pain compared to those with no or less pain.

Longitudinal change in quantitative meniscus measurements in knee osteoarthritis--data from the Osteoarthritis Initiative.

PubMed

Bloecker, Katja; Wirth, W; Guermazi, A; Hitzl, W; Hunter, D J; Eckstein, F

2015-10-01

We aimed to apply 3D MRI-based measurement technology to studying 2-year change in quantitative measurements of meniscus size and position. Forty-seven knees from the Osteoarthritis Initiative with medial radiographic joint space narrowing had baseline and 2-year follow-up MRIs. Quantitative measures were obtained from manual segmentation of the menisci and tibia using coronal DESSwe images. The standardized response mean (SRM = mean/SD change) was used as measure of sensitivity to longitudinal change. Medial tibial plateau coverage decreased from 34.8% to 29.9% (SRM -0.82; p < 0.001). Change in medial meniscus extrusion in a central image (SRM 0.18) and in the central five slices (SRM 0.22) did not reach significance, but change in extrusion across the entire meniscus (SRM 0.32; p = 0.03) and in the relative area of meniscus extrusion (SRM 0.56; p < 0.001) did. There was a reduction in medial meniscus volume (10%; p < 0.001), width (7%; p < 0.001), and height (2%; p = 0.08); meniscus substance loss was strongest in the posterior (SRM -0.51; p = 0.001) and weakest in the anterior horn (SRM -0.15; p = 0.31). This pilot study reports, for the first time, longitudinal change in quantitative 3D meniscus measurements in knee osteoarthritis. It provides evidence of improved sensitivity to change of 3D measurements compared with single slice analysis. • First longitudinal MRI-based measurements of change of meniscus position and size. • Quantitative longitudinal evaluation of meniscus change in knee osteoarthritis. • Improved sensitivity to change of 3D measurements compared with single slice analysis.

Empathy, Sense of Power, and Personality: Do They Change During Pediatric Residency?

PubMed

Greenberg, Larrie; Agrawal, Dewesh; Toto, Regina; Blatt, Benjamin

2015-08-01

Empathy is a critical competency in medicine. Prior studies demonstrate a longitudinal decrease in empathy during residency; however, they have not included pediatric residents. The relations among the expression of empathy, sense of power (ability to influence other's behavior), and personality traits in residents also have not been addressed. Lastly, there are no data on how residents compare with the general nonmedical population in their expression of empathy. The purposes of our study were to assess whether empathy, sense of power, and personality type were statistically correlated; if resident empathy declines over time; and how resident empathy compares with that of nonmedical peers. In 2010, a cohort of individuals entering pediatric residency were given three validated survey instruments at the beginning of their first and third years of training to explore longitudinal changes in empathy, sense of power, and major personality traits. We found no decrease in resident empathy in 2 years of pediatric training, no changes in their sense of power, and no statistically significant correlation between empathetic tendencies and sense of power. When compared with the general nonmedical population, pediatric residents rated themselves higher in empathy. As expected, the two components of empathy (empathic concern and perspective taking) were moderately correlated. Of the major personality traits, only agreeableness showed significant correlation with empathy. Pediatric resident empathy did not decrease longitudinally, unlike studies in other residents. There was no inverse relation between self-perceptions of sense of power and empathy as is present in the business literature. Finally, pediatric resident empathy was significantly higher when compared with a general nonmedical population.

The role of sleep disturbances in the longitudinal relationship between psychosocial working conditions, measured by work demands and support, and depression.

PubMed

Magnusson Hanson, Linda L; Chungkham, Holendro Singh; Åkerstedt, Torbjörn; Westerlund, Hugo

2014-12-01

Because work demands and lack of social support seem to be prospectively linked to sleep problems, and sleep problems are linked to depression, sleep problems may play a role in the relationship between these work characteristics and depressive symptoms. In order to shed more light on this relationship, the current study investigated whether disturbed sleep is a mediator in the longitudinal relationships between work demands, social support, and depression. Longitudinal cohort study with repeated survey measures on four occasions. Swedish workforce. 2,017 working participants from the Swedish Longitudinal Occupational Survey of Health in 2006, 2008, 2010, and 2012. Work demands (four items) and social support (six items) were assessed with the Demand Control Questionnaire, disturbed sleep (four items) with the Karolinska Sleep Questionnaire, and depressive symptoms with a brief subscale (six items) from the Symptom Checklist. Autoregressive longitudinal mediation models using structural equation modeling were tested. The work characteristics, and disturbed sleep, were found to be separately associated with depressive symptoms in subsequent waves. However, only demands were found to be longitudinally related to subsequent disturbed sleep. The longitudinal autoregressive models supported a weak mediating role of disturbed sleep in the relationship between demands and depressive symptoms (standardized beta 0.008, P < 0.001), but not between support and depressive symptoms. These results indicate that higher demands at work might cause an increase in depressive symptoms, in part, by increasing disturbed sleep, although the mediated effect was relatively small compared to the total effect. © 2014 Associated Professional Sleep Societies, LLC.

Differences in time to peak carbachol-induced contractions between circular and longitudinal smooth muscles of mouse ileum.

PubMed

Azuma, Yasu-Taka; Samezawa, Nanako; Nishiyama, Kazuhiro; Nakajima, Hidemitsu; Takeuchi, Tadayoshi

2016-01-01

The muscular layer in the GI tract consists of an inner circular muscular layer and an outer longitudinal muscular layer. Acetylcholine (ACh) is the representative neurotransmitter that causes contractions in the gastrointestinal tracts of most animal species. There are many reports of muscarinic receptor-mediated contraction of longitudinal muscles, but few studies discuss circular muscles. The present study detailed the contractile response in the circular smooth muscles of the mouse ileum. We used small muscle strips (0.2 mm × 1 mm) and large muscle strips (4 × 4 mm) isolated from the circular and longitudinal muscle layers of the mouse ileum to compare contraction responses in circular and longitudinal smooth muscles. The time to peak contractile responses to carbamylcholine (CCh) were later in the small muscle strips (0.2 × 1 mm) of circular muscle (5.7 min) than longitudinal muscles (0.4 min). The time to peak contractile responses to CCh in the large muscle strips (4 × 4 mm) were also later in the circular muscle (3.1 min) than the longitudinal muscle (1.4 min). Furthermore, a muscarinic M2 receptor antagonist and gap junction inhibitor significantly delayed the time to peak contraction of the large muscle strips (4 × 4 mm) from the circular muscular layer. Our findings indicate that muscarinic M2 receptors in the circular muscular layer of mouse ileum exert a previously undocumented function in gut motility via the regulation of gap junctions.

Comparing International and American Students: Involvement in College Life and Overall Satisfaction

ERIC Educational Resources Information Center

Zhou, Ji; Cole, Darnell

2017-01-01

Using longitudinal survey data, this study compares 191 international and 409 American students' involvement in college life, the extent to which the involvement is influenced by race/ethnicity, gender, and language background, and the extent to which the involvement influences overall satisfaction. Major findings include: International and…

Comparing Relations of Motivation, Engagement, and Achievement among Struggling and Advanced Adolescent Readers

ERIC Educational Resources Information Center

Klauda, Susan Lutz; Guthrie, John T.

2015-01-01

This longitudinal study examined the development of reading motivation, engagement, and achievement in early adolescence by comparing interrelations of these variables in struggling and advanced readers. Participants were 183 pairs of seventh grade students matched in gender, ethnicity, socioeconomic status, and school attended. They completed…

Longitudinal in vivo muscle function analysis of the DMSXL mouse model of myotonic dystrophy type 1.

PubMed

Decostre, Valérie; Vignaud, Alban; Matot, Béatrice; Huguet, Aline; Ledoux, Isabelle; Bertil, Emilie; Gjata, Bernard; Carlier, Pierre G; Gourdon, Geneviève; Hogrel, Jean-Yves

2013-12-01

Myotonic dystrophy is the most common adult muscle dystrophy. In view of emerging therapies, which use animal models as a proof of principle, the development of reliable outcome measures for in vivo longitudinal study of mouse skeletal muscle function is becoming crucial. To satisfy this need, we have developed a device to measure ankle dorsi- and plantarflexion torque in rodents. We present an in vivo 8-month longitudinal study of the contractile properties of the skeletal muscles of the DMSXL mouse model of myotonic dystrophy type 1. Between 4 and 12 months of age, we observed a reduction in muscle strength in the ankle dorsi- and plantarflexors of DMSXL compared to control mice although the strength per muscle cross-section was normal. Mild steady myotonia but no abnormal muscle fatigue was also observed in the DMSXL mice. Magnetic resonance imaging and histological analysis performed at the end of the study showed respectively reduced muscle cross-section area and smaller muscle fibre diameter in DMSXL mice. In conclusion, our study demonstrates the feasibility of carrying out longitudinal in vivo studies of muscle function over several months in a mouse model of myotonic dystrophy confirming the feasibility of this method to test preclinical therapeutics. Copyright © 2013 Elsevier B.V. All rights reserved.

Identification of treatment responders based on multiple longitudinal outcomes with applications to multiple sclerosis patients.

PubMed

Kondo, Yumi; Zhao, Yinshan; Petkau, John

2017-05-30

Identification of treatment responders is a challenge in comparative studies where treatment efficacy is measured by multiple longitudinally collected continuous and count outcomes. Existing procedures often identify responders on the basis of only a single outcome. We propose a novel multiple longitudinal outcome mixture model that assumes that, conditionally on a cluster label, each longitudinal outcome is from a generalized linear mixed effect model. We utilize a Monte Carlo expectation-maximization algorithm to obtain the maximum likelihood estimates of our high-dimensional model and classify patients according to their estimated posterior probability of being a responder. We demonstrate the flexibility of our novel procedure on two multiple sclerosis clinical trial datasets with distinct data structures. Our simulation study shows that incorporating multiple outcomes improves the responder identification performance; this can occur even if some of the outcomes are ineffective. Our general procedure facilitates the identification of responders who are comprehensively defined by multiple outcomes from various distributions. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

A bidimensional finite mixture model for longitudinal data subject to dropout.

PubMed

Spagnoli, Alessandra; Marino, Maria Francesca; Alfò, Marco

2018-06-05

In longitudinal studies, subjects may be lost to follow up and, thus, present incomplete response sequences. When the mechanism underlying the dropout is nonignorable, we need to account for dependence between the longitudinal and the dropout process. We propose to model such a dependence through discrete latent effects, which are outcome-specific and account for heterogeneity in the univariate profiles. Dependence between profiles is introduced by using a probability matrix to describe the corresponding joint distribution. In this way, we separately model dependence within each outcome and dependence between outcomes. The major feature of this proposal, when compared with standard finite mixture models, is that it allows the nonignorable dropout model to properly nest its ignorable counterpart. We also discuss the use of an index of (local) sensitivity to nonignorability to investigate the effects that assumptions about the dropout process may have on model parameter estimates. The proposal is illustrated via the analysis of data from a longitudinal study on the dynamics of cognitive functioning in the elderly. Copyright © 2018 John Wiley & Sons, Ltd.

Siblings of Adults with Mild Intellectual Deficits or Mental Illness: Differential Life Course Outcomes

PubMed Central

Taylor, Julie Lounds; Greenberg, Jan S.; Seltzer, Marsha Mailick; Floyd, Frank J.

2008-01-01

The present study contrasted the later life sibling relationships, patterns of family formation, and psychological distress and well-being of siblings of adults with disabilities to a non-disabled normative group. We identified 268 siblings of adults with mild intellectual deficits and 83 siblings of adults with mental illness from the Wisconsin Longitudinal Study, a prospective longitudinal study that followed participants from age 18 to age 64. Compared to the norm (n = 791), siblings of adults with mild intellectual deficits had more contact with family members and were more likely to live in the same state as the sibling with the disability, but reported less affective closeness. Siblings of adults with mental illness reported more psychological distress, less psychological well-being and less adaptive personality characteristics compared to the norm, particularly for siblings of men with mental illness. There were no differences between groups in the patterns of marriage and childbearing. PMID:19102611

Comparisons of foot anthropometry and plantar arch indices between German and Brazilian children.

PubMed

Sacco, Isabel C N; Onodera, Andrea N; Bosch, Kerstin; Rosenbaum, Dieter

2015-02-12

Nowadays, trades and research have become closely related between different countries and anthropometric data are important for the development in global markets. The appropriate use of anthropometry may improve wellbeing, health, comfort and safety especially for footwear design. For children a proper fit of footwear is very important, not constraining foot growth and allowing a normal development. The aim of this study was to compare the anthropometric characteristics of German and Brazilian children's feet from 3 to 10 years of age. We compared five indirect measures of two databases of children's feet. Forefoot, midfoot and rearfoot widths were measured in static footprints and the Chippaux-Smirak and Staheli indices of the longitudinal arch were calculated. Brazilian children showed a significantly narrower forefoot from 5 to 10 years, wider rearfoot from 3 to 4 years, wider midfoot for 4 year-olds and narrower midfoot for 10 year-old children. Nevertheless, the Chippaux-Smirak and Staheli indices showed no group differences. The only exception was for 4 year-old Brazilian children who showed a higher Chippaux-Smirak index compared to German children (48.4 ± 17.7%; 42.1 ± 13.8%). Our study revealed anthropometric differences in absolute forefoot and rearfoot widths of German and Brazilian children, but a similar longitudinal arch development. At 4 years of age, Brazilian children present a foot anthropometry similar to the 3 year-olds and develop the plantar longitudinal arch from 4 to 5 years more rapidly when compared to German children.

Assessment of score- and Rasch-based methods for group comparison of longitudinal patient-reported outcomes with intermittent missing data (informative and non-informative).

PubMed

de Bock, Élodie; Hardouin, Jean-Benoit; Blanchin, Myriam; Le Neel, Tanguy; Kubis, Gildas; Sébille, Véronique

2015-01-01

The purpose of this study was to identify the most adequate strategy for group comparison of longitudinal patient-reported outcomes in the presence of possibly informative intermittent missing data. Models coming from classical test theory (CTT) and item response theory (IRT) were compared. Two groups of patients' responses to dichotomous items with three times of assessment were simulated. Different cases were considered: presence or absence of a group effect and/or a time effect, a total of 100 or 200 patients, 4 or 7 items and two different values for the correlation coefficient of the latent trait between two consecutive times (0.4 or 0.9). Cases including informative and non-informative intermittent missing data were compared at different rates (15, 30 %). These simulated data were analyzed with CTT using score and mixed model (SM) and with IRT using longitudinal Rasch mixed model (LRM). The type I error, the power and the bias of the group effect estimations were compared between the two methods. This study showed that LRM performs better than SM. When the rate of missing data rose to 30 %, estimations were biased with SM mainly for informative missing data. Otherwise, LRM and SM methods were comparable concerning biases. However, regardless of the rate of intermittent missing data, power of LRM was higher compared to power of SM. In conclusion, LRM should be favored when the rate of missing data is higher than 15 %. For other cases, SM and LRM provide similar results.

Differential Olfactory Identification in Children with Autism and Asperger's Disorder: A Comparative and Longitudinal Study

ERIC Educational Resources Information Center

May, Tamara; Brewer, Warrick J.; Rinehart, Nicole J.; Enticott, Peter G.; Brereton, Avril V.; Tonge, Bruce J.

2011-01-01

Key theories of autism implicate orbitofrontal cortex (OFC) compromise, while olfactory identification (OI) deficits are associated with OFC dysfunction. This study aimed to complete a 5-year follow-up of children with high-functioning autism (HFA) who previously lacked the normal age-OI association; and compare unirhinal-OI in children with HFA,…

Parent-Adolescent Conflict and Adolescents' Adaptation: A Longitudinal Study of Albanian Immigrant Youth Living in Greece

ERIC Educational Resources Information Center

Motti-Stefanidi, Frosso; Pavlopoulos, Vassilis; Tantaros, Spyros

2011-01-01

This paper investigates the relationship between the frequency of parent-adolescent conflict and the quality of adaptation of immigrant Albanian adolescents and of their native Greek classmates. Aims of the present study were: (a) to compare the frequency of immigrant and non-immigrant adolescents' conflicts with their parents; (b) to compare the…

A Comparative Study of a Kodaly-Based Developmental Music Program and a Traditional Public School Music Program at the Kindergarten Level.

ERIC Educational Resources Information Center

Beatty, Rodger James

A 9-month longitudinal study of two kindergarten classes compared two types of music instruction: a Kodaly-based developmental music program and a traditional public school music program. The class taught through the Kodaly method received instruction that emphasized the development of rhythmic and melodic perception through visual, aural, and…

Longitudinal and cross-sectional analyses of visual field progression in participants of the Ocular Hypertension Treatment Study.

PubMed

Artes, Paul H; Chauhan, Balwantray C; Keltner, John L; Cello, Kim E; Johnson, Chris A; Anderson, Douglas R; Gordon, Mae O; Kass, Michael A

2010-12-01

To assess agreement between longitudinal and cross-sectional analyses for determining visual field progression in data from the Ocular Hypertension Treatment Study. Visual field data from 3088 eyes of 1570 participants (median follow-up, 7 years) were analyzed. Longitudinal analyses were performed using change probability with total and pattern deviation, and cross-sectional analyses were performed using the glaucoma hemifield test, corrected pattern standard deviation, and mean deviation. The rates of mean deviation and general height change were compared to estimate the degree of diffuse loss in emerging glaucoma. Agreement on progression in longitudinal and cross-sectional analyses ranged from 50% to 61% and remained nearly constant across a wide range of criteria. In contrast, agreement on absence of progression ranged from 97.0% to 99.7%, being highest for the stricter criteria. Analyses of pattern deviation were more conservative than analyses of total deviation, with a 3 to 5 times lesser incidence of progression. Most participants developing field loss had both diffuse and focal changes. Despite considerable overall agreement, 40% to 50% of eyes identified as having progressed with either longitudinal or cross-sectional analyses were identified with only one of the analyses. Because diffuse change is part of early glaucomatous damage, pattern deviation analyses may underestimate progression in patients with ocular hypertension.

Association of Combined Patterns of Tobacco and Cannabis Use in Adolescence With Psychotic Experiences

PubMed Central

Gage, Suzanne H.; Heron, Jon; Hickman, Matthew; Lewis, Glyn; Munafò, Marcus R.; Zammit, Stanley

2018-01-01

Importance There is concern about potentially causal effects of tobacco use on psychosis, but epidemiological studies have been less robust in attempts to minimize effects of confounding than studies of cannabis use have been. Objectives To examine the association of patterns of cigarette and cannabis use with preceding and subsequent psychotic experiences, and to compare effects of confounding across these patterns. Design, Setting, and Participants This cohort study used data from the Avon Longitudinal Study of Parents and Children, which initially consisted of 14 062 children. Data were collected periodically from September 6, 1990, with collection ongoing, and analyzed from August 8, 2016, through June 14, 2017. Cigarette and cannabis use data were summarized using longitudinal latent class analysis to identify longitudinal classes of substance use. Associations between classes and psychotic experiences at age 18 years were assessed. Exposures Depending on the analysis model, exposures were longitudinal classes of substance use or psychotic experiences at age 12 years. Main Outcomes and Measures Logistic regression was used to examine the associations between substance use longitudinal classes and subsequent onset of psychotic experiences. Results Longitudinal classes were derived using 5300 participants (56.1% female) who had at least 3 measures of cigarette and cannabis use from ages 14 to 19 years. Prior to adjusting for a range of potential confounders, there was strong evdience that early-onset cigarette-only use (4.3%), early-onset cannabis use (3.2%), and late-onset cannabis use (11.9%) (but not later-onset cigarette-only use [14.8%]) latent classes were associated with increased psychotic experiences compared with nonusers (65.9%) (omnibus P < .001). After adjusting for confounders, the association for early-onset cigarette-only use attenuated substantially (unadjusted odds ratio [OR], 3.03; 95% CI, 1.13-8.14; adjusted OR, 1.78; 95% CI, 0.54-5.88), whereas those for early-onset cannabis use (adjusted OR, 3.70; 95% CI, 1.66-8.25) and late-onset cannabis use (adjusted OR, 2.97; 95% CI, 1.63-5.40) remained consistent. Conclusions and Relevance In this study, our findings indicate that while individuals who use cannabis or cigarettes during adolescence have an increased risk of subsequent psychotic experiences, epidemiological evidence is substantively more robust for cannabis use than it is for tobacco use. PMID:29344610

A longitudinal and comparative study of psychological distress among professional workers in regulated occupations in Canada.

PubMed

Cadieux, Nathalie; Marchand, Alain

2014-01-01

Although several studies are concerned by the phenomenon of psychological distress at work, few studies have looked at the prevalence of psychological distress among professional workers in the regulated occupations and compare this prevalence with other occupations. This study propose to define regulated occupations by laying out the theoretical boundaries that apply to the practice of these occupations and try to understand how regulated occupations contributed to the experience of psychological distress in the Canadian workforce over time. Multilevel logistical regression analyses on longitudinal data were performed to compare the odds of experiencing psychological distress over time among professional workers in regulated occupations (n=276) and among other professional workers, classified into 6 categories (n=6731), over a 12-year period. The results show that proportion of distress in the workforce decreases for all occupations between Cycle 1 and Cycle 7 of the NPHS, but this decrease is not linear over time. The results show also that regulated occupations present a lower probability of psychological distress only when compared with white-collar workers. These results suggest that occupation contributes little toward understanding the prevalence of psychological distress in the Canadian workforce. Further research needs are also discussed.

The effect of compressive viscosity and thermal conduction on the longitudinal MHD waves

NASA Astrophysics Data System (ADS)

Bahari, K.; Shahhosaini, N.

2018-05-01

longitudinal Magnetohydrodynamic (MHD) oscillations have been studied in a slowly cooling coronal loop, in the presence of thermal conduction and compressive viscosity, in the linear MHD approximation. WKB method has been used to solve the governing equations. In the leading order approximation the dispersion relation has been obtained, and using the first order approximation the time dependent amplitude has been determined. Cooling causes the oscillations to amplify and damping mechanisms are more efficient in hot loops. In cool loops the oscillation amplitude increases with time but in hot loops the oscillation amplitude decreases with time. Our conclusion is that in hot loops the efficiency of the compressive viscosity in damping longitudinal waves is comparable to that of the thermal conduction.

Analysis of radial and longitudinal field of plasma wakefield generated by a Laguerre-Gauss laser pulse

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

Firouzjaei, Ali Shekari; Shokri, Babak

In the present paper, we study the wakes known as the donut wake which is generated by Laguerre-Gauss (LG) laser pulses. Effects of the special spatial profile of a LG pulse on the radial and longitudinal wakefields are presented via an analytical model in a weakly non-linear regime in two dimensions. Different aspects of the donut-shaped wakefields have been analyzed and compared with Gaussian-driven wakes. There is also some discussion about the accelerating-focusing phase of the donut wake. Variations of longitudinal and radial wakes with laser amplitude, pulse length, and pulse spot size have been presented and discussed. Finally, wemore » present the optimum pulse duration for such wakes.« less

The effect of compressive viscosity and thermal conduction on the longitudinal MHD waves

NASA Astrophysics Data System (ADS)

Bahari, K.; Shahhosaini, N.

2018-07-01

Longitudinal magnetohydrodynamic (MHD) oscillations have been studied in a slowly cooling coronal loop, in the presence of thermal conduction and compressive viscosity, in the linear MHD approximation. The WKB method has been used to solve the governing equations. In the leading order approximation the dispersion relation has been obtained, and using the first-order approximation the time-dependent amplitude has been determined. Cooling causes the oscillations to amplify and damping mechanisms are more efficient in hot loops. In cool loops the oscillation amplitude increases with time but in hot loops the oscillation amplitude decreases with time. Our conclusion is that in hot loops the efficiency of the compressive viscosity in damping longitudinal waves is comparable to that of the thermal conduction.

Gene expression models for prediction of longitudinal dispersion coefficient in streams

NASA Astrophysics Data System (ADS)

Sattar, Ahmed M. A.; Gharabaghi, Bahram

2015-05-01

Longitudinal dispersion is the key hydrologic process that governs transport of pollutants in natural streams. It is critical for spill action centers to be able to predict the pollutant travel time and break-through curves accurately following accidental spills in urban streams. This study presents a novel gene expression model for longitudinal dispersion developed using 150 published data sets of geometric and hydraulic parameters in natural streams in the United States, Canada, Europe, and New Zealand. The training and testing of the model were accomplished using randomly-selected 67% (100 data sets) and 33% (50 data sets) of the data sets, respectively. Gene expression programming (GEP) is used to develop empirical relations between the longitudinal dispersion coefficient and various control variables, including the Froude number which reflects the effect of reach slope, aspect ratio, and the bed material roughness on the dispersion coefficient. Two GEP models have been developed, and the prediction uncertainties of the developed GEP models are quantified and compared with those of existing models, showing improved prediction accuracy in favor of GEP models. Finally, a parametric analysis is performed for further verification of the developed GEP models. The main reason for the higher accuracy of the GEP models compared to the existing regression models is that exponents of the key variables (aspect ratio and bed material roughness) are not constants but a function of the Froude number. The proposed relations are both simple and accurate and can be effectively used to predict the longitudinal dispersion coefficients in natural streams.

Carotid endarterectomy: comparison of complications between transverse and longitudinal incision.

PubMed

Mendes, George A C; Zabramski, Joseph M; Elhadi, Ali M; Kalani, M Yashar S; Preul, Mark C; Nakaji, Peter; Spetzler, Robert F

2014-08-01

Cranial nerve injury (CNI) is the most common neurological complication associated with carotid endarterectomy (CEA). Some authors postulate that the transverse skin incision leads to increased risk of CNI. We compared the incidence of CNI associated with the transverse and longitudinal skin incisions in a high-volume cerebrovascular center. We reviewed the charts of 226 consecutive patients who underwent CEAs between January 2007 and August 2009. Pre- and postoperative standardized neurological evaluations were performed by faculty neurologists and neurosurgeons. One hundred sixty nine of 226 (75%) CEAs were performed with the use of a transverse incision. The longitudinal incision was generally reserved for patients with a high-riding carotid bifurcation. Mean patient age was 69 years (range, 45-91 years); 62% were men; 59% of patients were symptomatic and had high-grade stenosis (70%-99%). CNI occurred in 8 cases (3.5%): 5 (3%) in transverse and 3 (5.3%) with longitudinal incisions (P = .42). There were 2 marginal mandibular nerve injuries, 1 (0.6%) transverse and 1 longitudinal; 5 recurrent laryngeal nerve injuries, 4 transverse and 1 longitudinal; and 1 case of hypoglossal nerve injury associated with longitudinal incision. One hematoma was associated with CNI. All injuries were transient. Fourteen wound hematomas required surgical evacuation. The transverse skin incision for CEAs is not associated with an increased risk of CNI (P =.42). In this study, the incidence of CNI associated with the transverse incision was 3% (n = 5) vs 5% (n = 3) for longitudinal incisions. All CNIs were temporary.

Is 2D speckle tracking echocardiography useful for detecting and monitoring myocardial dysfunction in adult m.3243A>G carriers? - a retrospective pilot study.

PubMed

Koene, S; Timmermans, J; Weijers, G; de Laat, P; de Korte, C L; Smeitink, J A M; Janssen, M C H; Kapusta, L

2017-03-01

Cardiomyopathy is a common complication of mitochondrial disorders, associated with increased mortality. Two dimensional speckle tracking echocardiography (2DSTE) can be used to quantify myocardial deformation. Here, we aimed to determine the usefulness of 2DSTE in detecting and monitoring subtle changes in myocardial dysfunction in carriers of the 3243A>G mutation in mitochondrial DNA. In this retrospective pilot study, 30 symptomatic and asymptomatic carriers of the mitochondrial 3243A>G mutation of whom two subsequent echocardiograms were available were included. We measured longitudinal, circumferential and radial strain using 2DSTE. Results were compared to published reference values. Speckle tracking was feasible in 90 % of the patients for longitudinal strain. Circumferential and radial strain showed low face validity (low number of images with sufficient quality; suboptimal tracking) and were therefore rejected for further analysis. Global longitudinal strain showed good face validity, and was abnormal in 56-70 % (depending on reference values used) of the carriers (n = 27). Reproducibility was good (mean difference of 0.83 for inter- and 0.40 for intra-rater reproducibility; ICC 0.78 and 0.89, respectively). The difference between the first and the second measurement exceeded the measurement variance in 39 % of the cases (n = 23; feasibility of follow-up 77 %). Even in data collected as part of clinical care, two-dimensional strain echocardiography seems a feasible method to detect and monitor subtle changes in longitudinal myocardial deformation in adult carriers of the mitochondrial 3243A>G mutation. Based on our data and the reported accuracy of global longitudinal strain in other studies, we suggest the use of global longitudinal strain in a prospective follow-up or intervention study.

Longitudinal MR cortical thinning of individuals and its correlation with PET metabolic reduction: a measurement consistency and correctness studies

NASA Astrophysics Data System (ADS)

Lin, Zhongmin S.; Avinash, Gopal; McMillan, Kathryn; Yan, Litao; Minoshima, Satoshi

2014-03-01

Cortical thinning and metabolic reduction can be possible imaging biomarkers for Alzheimer's disease (AD) diagnosis and monitoring. Many techniques have been developed for the cortical measurement and widely used for the clinical statistical studies. However, the measurement consistency of individuals, an essential requirement for a clinically useful technique, requires proper further investigation. Here we leverage our previously developed BSIM technique 1 to measure cortical thickness and thinning and use it with longitudinal MRI from ADNI to investigate measurement consistency and spatial resolution. 10 normal, 10 MCI, and 10 AD subjects in their 70s were selected for the study. Consistent cortical thinning patterns were observed in all baseline and follow up images. Rapid cortical thinning was shown in some MCI and AD cases. To evaluate the correctness of the cortical measurement, we compared longitudinal cortical thinning with clinical diagnosis and longitudinal PET metabolic reduction measured using 3D-SSP technique2 for the same person. Longitudinal MR cortical thinning and corresponding PET metabolic reduction showed high level pattern similarity revealing certain correlations worthy of further studies. Severe cortical thinning that might link to disease conversion from MCI to AD was observed in two cases. In summary, our results suggest that consistent cortical measurements using our technique may provide means for clinical diagnosis and monitoring at individual patient's level and MR cortical thinning measurement can complement PET metabolic reduction measurement.

Longitudinal Assessment of Health-Related Quality of Life following Adolescent Sports-Related Concussion.

PubMed

Russell, Kelly; Selci, Erin; Chu, Stephanie; Fineblit, Samuel; Ritchie, Lesley; Ellis, Michael J

2017-07-01

To examine initial and longitudinal health-related quality of life (HRQOL) in adolescent sports-related concussion (SRC) patients, a prospective observational case-series study was conducted among adolescent SRC patients who were evaluated at a multi-disciplinary pediatric concussion program. Health-related quality of life was measured using the child self-report Pediatric Quality of Life Inventory (PedsQL) generic score scale (age 13-18 version) and the PedsQL Cognitive Functioning scale. Initial and longitudinal HRQOL outcomes were compared between patients who did and did not develop post-concussion syndrome (PCS). A total of 63 patients met the inclusion criteria during the study period. The mean age of the cohort was 14.57 years (standard deviation, 1.17) and 61.9% were male. The median time from injury to initial consultation was 6.5 days (interquartile range, 5, 11). At initial consultation, impairments in physical and cognitive HRQOL but not social or emotional HRQOL were observed. Initial symptom burden and length of recovery were associated with greater impairment in physical and cognitive HRQOL. Patients who went on to develop PCS had significantly worse physical and cognitive HRQOL at initial consultation and demonstrated a slower rate of recovery in these domains, compared with those who recovered in less than 30 days. Adolescent SRC was associated with HRQOL impairments that correlated with clinical outcomes. No persistent impairments in HRQOL were detected among patients who achieved physician-documented clinical recovery. Future studies are needed to evaluate the clinical utility of HRQOL measurement in the longitudinal management of adolescent SRC and PCS patients.

Antenatal and Postnatal Psychopathology Among Women with Current and Past Eating Disorders: Longitudinal Patterns

PubMed Central

Easter, Abigail; Solmi, Francessca; Bye, Amanda; Taborelli, Emma; Corfield, Freya; Schmidt, Ulrike; Treasure, Janet; Micali, Nadia

2015-01-01

This study aims to investigate longitudinal patterns of psychopathology during the antenatal and postnatal periods among women with current (C-ED) and past (P-ED) eating disorders. Women were recruited to a prospective longitudinal study: C-ED (n = 31), P-ED (n = 29) and healthy control (HC; n = 57). Anxiety, depression and ED symptoms were measured at four time points: first/second trimester, third trimester, 8 weeks and 6 months postpartum. Linear mixed effects models were used to test for group differences. Women with C-ED and P-ED, in all diagnostic categories, had significantly higher levels of psychopathology at all time points. ED symptoms decreased in the C-ED group, compared with an overall increase in the other two groups but subsequently increased after pregnancy. Overall, depression and state and trait anxiety scores decreased in the C-ED group compared with the HC group throughout the antenatal and postnatal periods. High levels of psychopathology are common throughout the antenatal and postnatal periods among women with current and past ED, and despite some overall reductions, symptoms remain clinically significant. © 2014 The Authors. European Eating Disorders Review published by John Wiley & Sons, Ltd. PMID:25345371

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

PubMed

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

2017-09-01

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

Is hypercortisolism in anorexia nervosa detectable using hair samples?

PubMed

Ritschel, Franziska; Clas, Sabine; Geisler, Daniel; Haas, Verena; Seidel, Maria; Steding, Julius; Roessner, Veit; Kirschbaum, Clemens; Ehrlich, Stefan

2018-03-01

Anorexia nervosa (AN) is a severe mental disorder accompanied by extensive metabolic and endocrine abnormalities. It has been associated with hypercortisolism using short-term measurement methods such as 24 h-urine, saliva, and blood. The aim of this study was to examine whether the proposed hypercortisolism in acutely underweight AN (acAN) is also reflected in a long-term measure: hair cortisol (HCC). To gain further insight, we compared hair cortisol to a well-established classical cortisol measure (24 h-urine; UCC) longitudinally in acAN. Hair samples were collected and analyzed using a LC-MS/MS-based method to provide a monthly cortisol value. We compared HCC in samples of 40 acAN with 40 pairwise age-matched healthy controls (HC) as well as 23 long-term recovered AN participants (recAN) with 23 pairwise age-matched HC (cross-sectional design). In the second part, UCC collected weekly during 14 weeks of weight-restoration therapy in 16 acAN was compared with the (time-corresponding) HCC using linear mixed models and bivariate correlations (longitudinal design). No group differences in HCC occurred comparing acAN and recAN to HC (cross-sectional study). The longitudinal analysis revealed a decrease of UCC but not HCC with weight gain. Furthermore, there was no overall significant association between UCC and HCC. Only in the last four weeks of weight-restoration therapy we found a significant moderate correlation between UCC and HCC. HCC did not reflect the expected hypercortisolism in acAN and did not decrease during short-term weight-restoration. Time-corresponding measurements of UCC and HCC were not consistently associated in our longitudinal analysis of acAN undergoing inpatient treatment. Given the drastic metabolic disturbances in acutely underweight AN our findings could be interpreted as disturbed cortisol incorporation or altered activity of 11-β-HSD-enzymes in the hair follicle. Copyright © 2017. Published by Elsevier Ltd.

Comparing statistical methods for analyzing skewed longitudinal count data with many zeros: an example of smoking cessation.

PubMed

Xie, Haiyi; Tao, Jill; McHugo, Gregory J; Drake, Robert E

2013-07-01

Count data with skewness and many zeros are common in substance abuse and addiction research. Zero-adjusting models, especially zero-inflated models, have become increasingly popular in analyzing this type of data. This paper reviews and compares five mixed-effects Poisson family models commonly used to analyze count data with a high proportion of zeros by analyzing a longitudinal outcome: number of smoking quit attempts from the New Hampshire Dual Disorders Study. The findings of our study indicated that count data with many zeros do not necessarily require zero-inflated or other zero-adjusting models. For rare event counts or count data with small means, a simpler model such as the negative binomial model may provide a better fit. Copyright © 2013 Elsevier Inc. All rights reserved.

Cultural Orientation Trajectories and Substance Use: Findings From a Longitudinal Study of Mexican-Origin Youth.

PubMed

Cruz, Rick A; King, Kevin M; Cauce, Ana M; Conger, Rand D; Robins, Richard W

2017-03-01

Cultural adaptation may influence Latino youth substance use (SU) development, yet few longitudinal studies have examined cultural change over time and adolescent SU outcomes. Using longitudinal data collected annually across ages 10-16 from 674 Mexican-origin youth (50% female), the authors characterized cultural adaptation patterns for language use (English and Spanish use), values (American values and familism values), and identity (ethnic pride), and examined whether these cultural adaptation patterns were associated with differential SU risk. Youth with increasing bilingualism and high/stable family values had lower SU risk compared to youth who primarily spoke English and endorsed decreasing family values, respectively. Ethnic pride trajectories were not associated with SU. Findings highlight the importance of considering cultural change related to Latino youth SU. © 2016 The Authors. Child Development © 2016 Society for Research in Child Development, Inc.

The longitudinal change of extracellular antioxidant status during pregnancy using an electron spin resonance method.

PubMed

Furukawa, Seishi; Nakajima, Akira; Sameshima, Hiroshi

2016-09-01

To evaluate the longitudinal change of extracellular antioxidant status during pregnancy. A longitudinal study involving 21 cases of pregnant women without medical disorders and had a vaginal birth was undertaken. Blood was obtained at early, mid and late pregnancy, labor onset, and postpartum day 1 and 5. We measured oxygen radical absorbance capacity (ORAC) and superoxide radical-eliminating ability (SREA) in serum using an electron spin resonance method. Twelve healthy volunteers were recruited as controls. Longitudinal and temporal changes were compared. ORAC increased significantly during the antepartum period (at early, mid and late pregnancy), decreased once during the peripartum period (in labor and day 1), and then recovered at day 5. SREA showed a similar tendency as ORAC. Interestingly, the ORAC of controls (919.7 ± 48.2 µmol TE/L) was significantly higher than those pregnant women at early pregnancy (early pregnancy: 699.2 ± 127.5, p < 0.01) and day 1 (740.3 ± 101.0, p < 0.01). The ORAC of controls was comparable to at late pregnancy and day 5 (1066.4 ± 189.6 and 920.3 ± 106.6, respectively). The SREA of controls (77.8 ± 31.2 arbitrary unit) was high, but there was no significant difference against the study group. Antioxidant ability of serum clearly fluctuated during periods that may be critical, namely, early pregnancy and peripartum period.

Outcomes of Left Ventricular Function According to Treatment Response for a Patent Ductus Arteriosus in Preterm Infants

PubMed Central

Cho, Young Sun; Hwang, Seo Jung; Kim, Hyo Jin

2017-01-01

Background To evaluate the outcomes of left ventricular (LV) function according to treatment response for a hemodynamically significant patent ductus arteriosus (hsPDA) in preterm infants. Methods Echocardiograms of 21 preterm infants born at gestational age < 31 weeks obtained at term-equivalent age were retrospectively studied. Among preterm infants with a hsPDA, 9 underwent ligation after failure of pharmacological closure (ligation group) and 6 experienced successful pharmacological closure (medication group). Six preterm infants without hsPDA (no-hsPDA group) were studied as controls. LV peak longitudinal systolic strain (ε) of each infant was retrospectively obtained from echocardiograms using velocity vector imaging, along with neonatal outcomes. Results Pharmacological closures were attempted at postnatal day 2–3. In the ligation group, the median postnatal age at ligation was 20 days. In the ligation group, LV peak longitudinal systolic ε was significantly decreased at term-equivalent age compared to the other groups. Between the medication and no-hsPDA groups, LV peak longitudinal systolic ε did not differ significantly. Among the neonatal outcomes, infants who experienced necrotizing enterocolitis (NEC) showed significantly decreased LV peak longitudinal systolic ε compared to the infants who did not experience NEC . Conclusion We speculate that in preterm infants with an hsPDA, in cases of medical treatment failure, early PDA ligation at less than 20 days of postnatal age would be beneficial for preserving LV systolic function. PMID:29333220

Longitudinal volume changes of the pituitary gland in patients with schizotypal disorder and first-episode schizophrenia.

PubMed

Takahashi, Tsutomu; Zhou, Shi-Yu; Nakamura, Kazue; Tanino, Ryoichiro; Furuichi, Atsushi; Kido, Mikio; Kawasaki, Yasuhiro; Noguchi, Kyo; Seto, Hikaru; Kurachi, Masayoshi; Suzuki, Michio

2011-01-15

An enlarged volume of the pituitary gland has been reported in the schizophrenia spectrum, possibly reflecting the hypothalamic-pituitary-adrenal (HPA) hyperactivity. However, it remains largely unknown whether the pituitary size longitudinally changes in the course of the spectrum disorders. In the present study, longitudinal magnetic resonance imaging (MRI) data were obtained from 18 patients with first-episode schizophrenia, 13 patients with schizotypal disorder, and 20 healthy controls. The pituitary volume was measured at baseline and follow-up (mean, 2.7 years) scans and was compared across groups. The pituitary volume was larger in the schizophrenia patients than controls at baseline, and both patient groups had significantly larger pituitary volume than controls at follow-up. In a longitudinal comparison, both schizophrenia (3.6%/year) and schizotypal (2.7%/year) patients showed significant pituitary enlargement compared with controls (-1.8%/year). In the schizophrenia patients, greater pituitary enlargement over time was associated with less improvement of delusions and higher scores for thought disorders at the follow-up. These findings suggest that the pituitary gland exhibits ongoing volume changes during the early course of the schizophrenia spectrum as a possible marker of state-related impairments. Copyright © 2010 Elsevier Inc. All rights reserved.

Design of piezoelectric probe for measurement of longitudinal and shear components of elastic wave

NASA Astrophysics Data System (ADS)

Aoyanagi, Masafumi; Wakatsuki, Naoto; Mizutani, Koichi; Ebihara, Tadashi

2017-07-01

We focus on ultrasonic probes for nondestructive tests and evaluation. Transient characteristics of probes are important for nondestructive tests such as the pulse echo method. We previously reported the principle of measurement using a piezoelectric probe with triaxial sensitivities. In the results, it was calculated that the probe could transmit and receive particle displacement which contains normal and tangential components. It was confirmed that the probe had sensitivities in triaxial directions. However, its performance in terms of frequency and transient characteristics has not been evaluated. The purpose of this study is to design a probe by changing its shape to obtain better performance. The transient characteristics of probes in longitudinal and shear driving were evaluated by the inverse Fourier transformation of frequency responses of longitudinal and shear components, using the two-dimensional finite element method. As a result, the sensitivities at the dips of frequency characteristics increased when using our probe compared with those measured using conventional probes in longitudinal and shear driving. Hence, the performance in terms of the frequency response was improved by more than 3 dB under the conditions in this simulation. Also, the pulse width of impulse response was decreased by half compared with that of probes with conventional shapes.

Does relationship satisfaction and financial aid from offspring influence the quality of life of older parents?: a longitudinal study based on findings from the Korean longitudinal study of aging, 2006-2012.

PubMed

Ju, Yeong Jun; Han, Kyu-Tae; Lee, Tae-Hoon; Kim, Woorim; Kim, Juyeong; Park, Eun-Cheol

2016-07-26

Quality of life (QoL) in old age is of major importance because the global population is aging rapidly. Offspring support, including financial and emotional support, is important in later life and directly affects the wellbeing of elderly individuals. The aim of this study was to examine the relationship between QoL in older parents and offspring support. We used baseline data from the 2006-2012 Korean Longitudinal Study of Aging, from 3,274 individuals aged 65 years or older. We measured the individual's QoL using a visual analog scale and included both relationship satisfaction and regular economic support as variables. A generalized estimating equation (GEE) model was used to perform longitudinal regression analysis on the data. Regarding the QoL of older parents, those with an unsatisfying relationship with their offspring had a QoL of -21.93 (SE = 0.55; P < 0.0001) compared to those with satisfying offspring relationships. Those receiving no regular financial aid from their offspring had a QoL of -0.92 (SE = 0.38; P = 0.0171) compared to those who received such economic support. Combination effects were observed, with cases living alone - and having poor offspring relationships and no regular financial support from their offspring - showing the most drastic decrease in QoL (-23.46; SE = 1.03; P < 0.0001). Offspring support influences the QoL of elderly individuals, and Korean children appear to play a crucial role in the QoL of their (older) parents. Considering that the role of offspring is rapidly diminishing due to industrialization policies, initiatives are required to revitalize offspring support for elderly parents.

Early detection of cardiac involvement in sarcoidosis with 2-dimensional speckle-tracking echocardiography.

PubMed

Schouver, Elie-Dan; Moceri, Pamela; Doyen, Denis; Tieulie, Nathalie; Queyrel, Viviane; Baudouy, Delphine; Cerboni, Pierre; Gibelin, Pierre; Leroy, Sylvie; Fuzibet, Jean-Gabriel; Ferrari, Emile

2017-01-15

Cardiac sarcoidosis (CS) is associated with high morbidity and sudden death. The absence of specific symptoms and lack of diagnostic gold standard technique is challenging. New imaging methods could improve the diagnosis of CS. The aim of our study was to assess the role of left ventricular (LV) longitudinal and circumferential strain as estimated by 2D speckle-tracking imaging in patients with diagnosed sarcoidosis without cardiac involvement according to the current guidelines. We investigated the prevalence of LV strain impairment in this population and assessed its relationship with clinical outcomes, composite of mortality, heart failure, arrhythmia and/or secondarily development of CS and cardiac device implantation. We performed a prospective case-control longitudinal study including 35 patients with diagnosed sarcoidosis and normal cardiac function as assessed by standard transthoracic echocardiography and 35 healthy age- and gender-matched controls. All patients underwent a comprehensive echocardiographic study. Mean age of patients was 47.9±14.8years old (22 women). Compared with controls, global LV longitudinal strain (LV GLS) was reduced in sarcoidosis patients: (-17.2±3.1 vs -21.3±1.5%, p<0.0001). Circumferential LV strain was preserved in patients compared to controls (-19.9±-4.3% vs -21.3±1.5%, p=0.12). Impaired LV GLS was significantly associated with clinical outcomes (HR 1.56; [1.16-2.11], p<0.01) on univariate analysis. Speckle-tracking echocardiography revealed decreased longitudinal LV strain in sarcoidosis patients that was associated with outcomes. LV GLS may represent an early marker of myocardial involvement in sarcoidosis patients that needs to be studied further. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Longitudinal left ventricular function for prediction of survival in systemic light-chain amyloidosis: incremental value compared with clinical and biochemical markers.

PubMed

Buss, Sebastian J; Emami, Mostafa; Mereles, Derliz; Korosoglou, Grigorios; Kristen, Arnt V; Voss, Andreas; Schellberg, Dieter; Zugck, Christian; Galuschky, Christian; Giannitsis, Evangelos; Hegenbart, Ute; Ho, Anthony D; Katus, Hugo A; Schonland, Stefan O; Hardt, Stefan E

2012-09-18

The aim of the study was to determine whether longitudinal left ventricular (LV) function provides prognostic information in a large cohort of patients with systemic light-chain (AL) amyloidosis. AL amyloidosis is associated with a high incidence of cardiovascular events. Reduced myocardial longitudinal function is one of the hallmarks of myocardial involvement in this rare disease. Two hundred six consecutive patients with biopsy-proven AL amyloidosis were investigated in this prospective observational study. Echocardiographic imaging parameters, mean tissue Doppler-derived longitudinal strain (LS), and two-dimensional global longitudinal strain (2D-GLS) of the LV, cardiac serological biomarkers, and comprehensive clinical disease characteristics were assessed. The primary endpoint was all-cause mortality or heart transplantation. After a median follow-up of 1207 days, LS and 2D-GLS were significant predictors of survival in AL amyloidosis. The cutoff values discriminating survivors from nonsurvivors were -10.65% for LS and -11.78% for 2D-GLS. In a multivariable echocardiographic Cox model, only diastolic dysfunction and 2D-GLS remained as independent predictors of survival. In comprehensive clinical models, 2D-GLS (p < 0.0001), diastolic dysfunction (p < 0.01), the pathologic free light chains (p < 0.05), cardiac troponin-T (cTnT) (p < 0.01), and the Karnofsky index (p < 0.001) remained as independent predictors. 2D-GLS delineated a superior prognostic value compared with that derived from pathologic free light chains or cTnT in patients evaluated before firstline chemotherapy (n = 113; p < 0.0001), and remained the only independent predictor besides the Karnofsky index in subjects with preserved LV ejection fraction (≥50%; n = 127; p < 0.01). LS and 2D-GLS both offered significant incremental information (p < 0.001) for the assessment of outcome compared with clinical variables (age, Karnofsky index, and New York Heart Association functional class) and serological biomarkers. In the largest serial investigation reported so far, reduced LV longitudinal function served as an independent predictor of survival in AL amyloidosis and offered incremental information beyond standard clinical and serological parameters. Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

The built environment and physical activity levels: the Harvard Alumni Health Study.

PubMed

Lee, I-Min; Ewing, Reid; Sesso, Howard D

2009-10-01

Physical activity is associated with better health, but many individuals are insufficiently active. Modifying the built environment may be an approach capable of influencing population-wide levels of physical activity, but few data exist from longitudinal studies that can minimize bias from active people choosing activity-friendly neighborhoods. This study aims to examine cross-sectional and longitudinal associations between the built environment and physical activity on a large scale. This study examined cross-sectional associations between urban sprawl (mapping addresses to corresponding counties) and physical activity (self-reported) among men throughout the U.S. in 1993 and in 1988, and longitudinal associations between changes in exposure to urban sprawl for movers and physical activity, 1988-1993. Included were 4997 men (mean age, 70 years) in the 1993 cross-sectional study; 4918 men in the 1988 cross-sectional study; and 3448 men in the longitudinal study, 1988-1993. Data were collected prospectively in 1988 and 1993, and analyses were performed in 2007-2008. In cross-sectional analyses, less sprawl was significantly associated with more walking OR, comparing least with most sprawling areas, for meeting physical activity recommendations by walking=1.38 [95% CI=1.09, 1.76] in 1993 and 1.53 [1.19, 1.96] in 1988). Less sprawl also was associated with lower prevalence of overweight (corresponding OR=0.79 [0.64, 0.98] in 1993 and 0.81 [0.66, 1.00] in 1988). However, longitudinal analyses assessing change did not show that decreasing sprawl was associated with increased physical activity or decreased BMI. These findings suggest that the cross-sectional results may reflect self-selection, rather than indicating that the built environment--as measured by urban sprawl--increases physical activity. However, the longitudinal findings were limited by small numbers of men changing residence and associated sprawl levels.

Relationship between the built environment and physical activity levels: The Harvard Alumni Health Study

PubMed Central

Lee, I-Min; Ewing, Reid; Sesso, Howard D.

2009-01-01

Background Physical activity is associated with better health, but many individuals are insufficiently active. Modifying the built environment may be an approach capable of influencing population-wide levels of physical activity, but few data exist from longitudinal studies that can minimize bias from active persons choosing activity-friendly neighborhoods. This is the first large-scale study to examine longitudinal changes in the built environment and physical activity. Methods This study examined cross-sectional associations between urban sprawl (mapping addresses to corresponding counties) and physical activity (self-reported) among men throughout the US in 1993 and in 1988, and longitudinal associations between changes in exposure to urban sprawl for movers and physical activity, 1988-1993. Included were 4,997 men (mean age, 70 years) in the 1993 cross-sectional study; 4,918 men in the 1988 cross-sectional study; and 3,448 men in the longitudinal study, 1988-1993. Data were collected prospectively in 1988 and 1993, and analyses were performed in 2007-2008. Results In cross-sectional analyses, less sprawl was significantly associated with more walking (odds ratios (OR), comparing least with most sprawling areas, for meeting physical activity recommendations by walking = 1.38 [95% confidence interval = 1.09, 1.76] in 1993 and 1.53 [1.19, 1.96] in 1988). Less sprawl also was associated with lower prevalence of overweight (corresponding OR = 0.79 [0.64, 0.98] in 1993 and 0.81 [0.66-1.00] in 1988). However, longitudinal analyses assessing change did not show that decreasing sprawl was associated with increased physical activity or decreased body mass index. Conclusions These findings suggest that the cross-sectional results may reflect self-selection, rather than indicating that the built environment – as measured by urban sprawl – increases physical activity. However, the longitudinal findings were limited by small numbers of men changing residence and associated sprawl levels. PMID:19765500

Studies of longitudinal profile of electron bunches and impedance measurements at Indus-2 synchrotron radiation source

NASA Astrophysics Data System (ADS)

Garg, Akash Deep; Yadav, S.; Kumar, Mukesh; Shrivastava, B. B.; Karnewar, A. K.; Ojha, A.; Puntambekar, T. A.

2016-04-01

Indus-2 is a 3rd generation synchrotron radiation source at the Raja Ramanna Centre for Advanced Technology (RRCAT) in India. We study the longitudinal profile of electrons in Indus-2 by using dual sweep synchroscan streak camera at visible diagnostic beamline. In this paper, the longitudinal profiles of electron bunch are analyzed by filling beam current in a single bunch mode. These studies are carried at injection energy (550 MeV) and at ramped beam energy (2.5 GeV). The effects of the wakefield generated interactions between the circulating electrons and the surrounding vacuum chamber are analyzed in terms of measured effects on longitudinal beam distribution. The impedance of the storage ring is obtained by fitting the solutions of Haissinski equation to the measured bunch lengthening with different impedance models. The impedance of storage ring obtained by a series R+L impedance model indicates a resistance (R) of 1350±125 Ω, an inductance (L) of 180±25 nH and broadband impedance of 2.69 Ω. These results are also compared with the values obtained from measured synchronous phase advancing and scaling laws. These studies are very useful in better understanding and control of the electromagnetic interactions.

Risky business: a longitudinal study examining cigarette smoking initiation among susceptible and non-susceptible e-cigarette users in Canada

PubMed Central

Aleyan, Sarah; Cole, Adam; Qian, Wei; Leatherdale, Scott T

2018-01-01

Objectives Given that many adolescent e-cigarette users are never-smokers, the possibility that e-cigarettes may act as a gateway to future cigarette smoking has been discussed in various studies. Longitudinal data are needed to explore the pathway between e-cigarette and cigarette use, particularly among different risk groups including susceptible and non-susceptible never-smokers. The objective of this study was to examine whether baseline use of e-cigarettes among a sample of never-smoking youth predicted cigarette smoking initiation over a 2-year period. Design Longitudinal cohort study. Setting 89 high schools across Ontario and Alberta, Canada. Participants A sample of grade 9–11 never-smoking students at baseline (n=9501) who participated in the COMPASS study over 2 years. Primary and secondary outcome measures Participants completed in-class questionnaires that assessed smoking susceptibility and smoking initiation. Results Among the baseline sample of non-susceptible never-smokers, 45.2% of current e-cigarette users reported trying a cigarette after 2 years compared with 13.5% of non-current e-cigarette users. Among the baseline sample of susceptible never-smokers, 62.4% of current e-cigarette users reported trying a cigarette after 2 years compared with 36.1% of non-current e-cigarette users. Overall, current e-cigarette users were more likely to try a cigarette 2 years later. This association was stronger among the sample of non-susceptible never-smokers (AOR=5.28, 95% CI 2.81 to 9.94; p<0.0001) compared with susceptible never-smokers (AOR=2.78, 95% CI 1.84 to 4.20; p<0.0001). Conclusions Findings from this large, longitudinal study support public health concerns that e-cigarette use may contribute to the development of a new population of cigarette smokers. They also support the notion that e-cigarettes are expanding the tobacco market by attracting low-risk youth who would otherwise be unlikely to initiate using cigarettes. Careful consideration will be needed in developing an appropriate regulatory framework that prevents e-cigarette use among youth. PMID:29804064

Comparative Effectiveness of PCI Education's "PCI Reading Program": Phase 2--A Report of a Comparison Group Study in Brevard Public Schools and Miami-Dade County Public Schools. Research Summary

ERIC Educational Resources Information Center

Empirical Education Inc., 2010

2010-01-01

PCI Education sought scientifically based evidence on the comparative effectiveness of the "PCI Reading Program" through a five-year longitudinal study. Phase 1 of the study consisted of a randomized control trial studying the efficacy of the "PCI Reading Program-Level One" that was conducted in the 2007-2008 in Miami-Dade…

Literacy Achievement in Nongraded Classrooms

ERIC Educational Resources Information Center

Kreide, Anita Therese

2011-01-01

This longitudinal quantitative study compared literacy achievement of students from second through sixth grade based on two organizational systems: graded (traditional) and nongraded (multiage) classrooms. The California Standards Test (CST) scaled and proficiency scores for English-Language Arts (ELA) were used as the study's independent variable…

Social support and health-related quality of life in women with breast cancer: a longitudinal study.

PubMed

Leung, Janni; Pachana, Nancy A; McLaughlin, Deirdre

2014-09-01

A breast cancer diagnosis is a distressing event that impacts on physical and psychological functioning. This study examined the longitudinal relationships among a diagnosis of breast cancer, social support, and health-related quality of life (HRQOL). Participants were 412 women from the 1946-1951 birth cohort of the Australian Longitudinal Study on Women's Health who self-reported a new diagnosis of breast cancer between 1998 and 2007. The three surveys of longitudinal data analyzed included data 3 years before diagnosis, at diagnosis (baseline), and 3 years after diagnosis (follow-up). Social support was measured using the 19-item Medical Outcomes Study Social Support Survey; HRQOL was measured using the Medical Outcomes Study 36-item Short-Form Health Survey. Compared with pre-diagnosis HRQOL, women newly diagnosed with breast cancer reported significantly poorer HRQOL in subscales related to pain, physical functioning, and health and vitality. At 3-year follow-up, HRQOL had improved in most domains to levels consistent with pre-diagnosis. Levels of social support remained stable across time. The structural equation model showed that social support was positively predictive of better physical and mental HRQOL at 3-year follow-up. Longitudinal analyses indicate that social support appears to be an important predictor of HRQOL in women diagnosed with breast cancer. In particular, positive emotional and informational support that may normally be provided by a partner is important in maintaining HRQOL. Identification of those lacking social support, especially patients without partners, will enable them to be guided to appropriate support networks and programs. Copyright © 2014 John Wiley & Sons, Ltd.

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

PubMed

Liu, Xian; Engel, Charles C

2012-12-20

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

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.

Has the inclusion of a longitudinally integrated communication skills program improved consultation skills in medical students? A pilot study.

PubMed

Shah, Sameena; Andrades, Marie; Basir, Fasia; Jaleel, Anila; Azam, Iqbal; Islam, Muhammad; Ahmed, Rashida

2016-01-01

Evidence highlights a lack of communication skills in doctors leading to dysfunctional consultations. To address this deficit, a private medical college instituted curricular reforms with inclusion of a longitudinal communication skills program. A pilot study was undertaken to evaluate the effectiveness of this program by comparing the consultation skills of medical students of this college with a medical college without a communication skills program. A 4-station Objective Structured Clinical Examination (OSCE) was conducted in the third and final year. Mann-Whitney U-test was used to compare the difference in the distribution between OSCE stations total and construct scores. At the end of the third year, 21 (31.34%), students of the study site (medical college 1 [college with integrated longitudinal communication skills program]) and 31 (46.26%) students from the comparison site (medical college 2 [comparable college without communication skills program]) consented. Medical college 1 achieved a significantly higher overall mean total station score of 68.0% (standard deviation [SD] =13.5) versus 57.2% (SD = 15.4) (P < 0.001). Significantly higher mean scores were achieved on three stations. At the end of the final year, 19 students (29.3%) from medical college 1 and 22 (34%) students from medical college 2 consented. The difference in overall mean total station score reduced from 9.2% to 7.1% (70.2) (SD = 13.7) versus 63.1 (SD = 15.2) (P = 0.004). The mean scores of both colleges decreased in "Patient presenting with Hepatitis C Report" station (P values 0.004 and 0.775) and in "Patient Request for Faith Healing Therapy in Diabetes Mellitus" station (P values 0.0046 and 0.036), respectively. Longitudinal communication skills in an undergraduate curriculum positively impacted consultation skills. Community-based training and faculty development are required to develop effective patient-centered consultation skills.

Tool Trouble: Challenges with Using Self-Report Data to Evaluate Long-Term Chemistry Teacher Professional Development

ERIC Educational Resources Information Center

Herrington, Deborah G.; Yezierski, Ellen J.; Bancroft, Senetta F.

2016-01-01

The purpose of this study was to compare the ability of different instruments, independently developed and traditionally used for measuring science teachers' beliefs in short-term interventions, to longitudinally measure teachers' changing beliefs. We compared the ability of three self-report instruments (Science Teaching Efficacy Belief…

Saturday Morning Children's Television Advertising: A Longitudinal Content Analysis.

ERIC Educational Resources Information Center

Byrd-Bredbenner, Carol

2002-01-01

Content of ads on Saturday children's television programs in 1993 (n=378) and 1999 (n=385) was compared with dietary recommendations and advertising guidelines. Cereals and foods high in sugar or fat dominated ads. Results were compared with earlier studies, finding that over 30 years, ads adhered to advertising guidelines but did not reflect…

Comparing Indicators of Sexual Sadism as Predictors of Recidivism among Adult Male Sexual Offenders

ERIC Educational Resources Information Center

Kingston, Drew A.; Seto, Michael C.; Firestone, Philip; Bradford, John M.

2010-01-01

Objective: In this longitudinal study, the predictive validity of a psychiatric diagnosis of sexual sadism was compared with three behavioral indicators of sadism: index sexual offense violence, sexual intrusiveness, and phallometrically assessed sexual arousal to depictions of sexual or nonsexual violence. Method: Five hundred and eighty six…

Psychological Implications of Motherhood and Fatherhood in Midlife: Evidence from Sibling Models

ERIC Educational Resources Information Center

Pudrovska, Tetyana

2008-01-01

Using data from 4,744 full, twin, half-, adopted, and stepsiblings in the Wisconsin Longitudinal Study, I examine psychological consequences of motherhood and fatherhood in midlife. My analysis includes between-family models that compare individuals across families and within-family models comparing siblings from the same family to account for…

A Systematic Review and Meta-Analysis of The Effect of Low Vitamin D on Cognition.

PubMed

Goodwill, Alicia M; Szoeke, Cassandra

2017-10-01

With an aging population and no cure for dementia on the horizon, risk factor modification prior to disease onset is an urgent health priority. Therefore, this review examined the effect of low vitamin D status or vitamin D supplementation on cognition in midlife and older adults without a diagnosis of dementia. Systematic review and random effect meta-analysis. Observational (cross-sectional and longitudinal cohort) studies comparing low and high vitamin D status and interventions comparing vitamin D supplementation with a control group were included in the review and meta-analysis. Studies including adults and older adults without a dementia diagnosis were included. Medline (PubMed), AMED, Psych INFO, and Cochrane Central databases were searched for articles until August 2016. The Newcastle-Ottawa Scale and Physiotherapy Evidence Database assessed methodological quality of all studies. Twenty-six observational and three intervention studies (n = 19-9,556) were included in the meta-analysis. Low vitamin D was associated with worse cognitive performance (OR = 1.24, CI = 1.14-1.35) and cognitive decline (OR = 1.26, CI = 1.09-1.23); with cross-sectional yielding a stronger effect compared to longitudinal studies. Vitamin D supplementation showed no significant benefit on cognition compared with control (SMD = 0.21, CI = -0.05 to 0.46). Observational evidence demonstrates low vitamin D is related to poorer cognition; however, interventional studies are yet to show a clear benefit from vitamin D supplementation. From the evidence to date, there is likely a therapeutic age window relevant to the development of disease and therefore vitamin D therapy. Longitudinal lifespan studies are necessary to depict the optimal timing and duration in which repletion of vitamin D may protect against cognitive decline and dementia in aging, to better inform trials and practice towards a successful therapy. © 2017, Copyright the Authors Journal compilation © 2017, The American Geriatrics Society.

Relative survival: a useful tool to assess generalisability in longitudinal studies of health in older persons

PubMed Central

2011-01-01

Background Generalisability of longitudinal studies is threatened by issues such as choice of sampling frame, representativeness of the initial sample, and attrition. To determine representativeness, cohorts are often compared with the population of interest at baseline on demographic and health characteristics. This study illustrates the use of relative survival as a tool for assessing generalisability of results from a cohort of older people among whom death is a potential threat to generalisability. Methods The authors used data from the 1921-26 cohort (n = 12,416, aged 70-75 in 1996) of the Australian Longitudinal Study on Women's Health (ALSWH). Vital status was determined by linkage to the National Death Index, and expected deaths were derived using Australian life tables. Relative survival was estimated using observed survival in the cohort divided by expected survival among women of the same age and State or Territory. Results Overall, the ALSWH women showed relative survival 9.5% above the general population. Within States and Territories, the relative survival advantage varied from 6% to 23%. The interval-specific relative survival remained relatively constant over the 12 years (1996-2008) under review, indicating that the survival advantage of the cohort has not diminished over time. Conclusion This study demonstrates that relative survival can be a useful measure of generalisability in a longitudinal study of the health of the general population, particularly when participants are older. PMID:21294918

Testing healthy immigrant effects among late life immigrants in the United States: using multiple indicators.

PubMed

Choi, Sunha H

2012-04-01

This study tested a healthy immigrant effect (HIE) and postimmigration health status changes among late life immigrants. Using three waves of the Second Longitudinal Study of Aging (1994-2000) and the linked mortality file through 2006, this study compared (a) chronic health conditions, (b) longitudinal trajectories of self-rated health, (c) longitudinal trajectories of functional impairments, and (d) mortality between three groups (age 70+): (i) late life immigrants with less than 15 years in the United States (n = 133), (ii) longer term immigrants (n = 672), and (iii) U.S.-born individuals (n = 8,642). Logistic and Poisson regression, hierarchical generalized linear modeling, and survival analyses were conducted. Late life immigrants were less likely to suffer from cancer, had lower numbers of chronic conditions at baseline, and displayed lower hazards of mortality during the 12-year follow-up. However, their self-rated health and functional status were worse than those of their counterparts over time. A HIE was only partially supported among older adults.

Within- and between-person and group variance in behavior and beliefs in cross-cultural longitudinal data.

PubMed

Deater-Deckard, Kirby; Godwin, Jennifer; Lansford, Jennifer E; Bacchini, Dario; Bombi, Anna Silvia; Bornstein, Marc H; Chang, Lei; Di Giunta, Laura; Dodge, Kenneth A; Malone, Patrick S; Oburu, Paul; Pastorelli, Concetta; Skinner, Ann T; Sorbring, Emma; Steinberg, Laurence; Tapanya, Sombat; Alampay, Liane Peña; Uribe Tirado, Liliana Maria; Zelli, Arnaldo; Al-Hassan, Suha M

2018-01-01

This study grapples with what it means to be part of a cultural group, from a statistical modeling perspective. The method we present compares within- and between-cultural group variability, in behaviors in families. We demonstrate the method using a cross-cultural study of adolescent development and parenting, involving three biennial waves of longitudinal data from 1296 eight-year-olds and their parents (multiple cultures in nine countries). Family members completed surveys about parental negativity and positivity, child academic and social-emotional adjustment, and attitudes about parenting and adolescent behavior. Variance estimates were computed at the cultural group, person, and within-person level using multilevel models. Of the longitudinally consistent variance, most was within and not between cultural groups-although there was a wide range of between-group differences. This approach to quantifying cultural group variability may prove valuable when applied to quantitative studies of acculturation. Copyright © 2017 The Foundation for Professionals in Services for Adolescents. All rights reserved.

Longitudinal analysis of the effect of academic failure tolerance on academic achievement fluctuation in medical school students.

PubMed

Chae, Su Jin; Kim, Miran; Chang, Ki Hong

2016-03-01

Academic failure tolerance (AFT) is one of the important psychological concepts in education, but its applications in medical education are rare. Thus, the purpose of this study was to investigate the effect of academic failure tolerance on academic achievement fluctuation among medical school students using a longitudinal research design. The subjects were 43 medical students who responded to the AFT test. This study analyzed the longitudinal data of achievement scores up to the 2nd academic year (2012-2013) among students who were divided into academic achievement improvement and decline groups. Comparing the improvement and decline groups' mean academic achievement fluctuation scores demonstrated that behavior and preferred task difficulty showed high scores whereas feeling scores were lower in the improvement group (p<0.05). In the improvement group, despite the higher negative feeling scores during academic failure, the students favored the more difficult subjects and were more assiduous in their studies. This will form an important basis for enhancing academic achievement among medical students.

A Longitudinal Study of Early Reading Development in Two Languages: Comparing Literacy Outcomes in Irish Immersion, English Medium and Gaeltacht Schools

ERIC Educational Resources Information Center

Parsons, Christine E.; Lyddy, Fiona

2016-01-01

Schools in Ireland vary in how they introduce reading in the two official languages, Irish and English. There is particular variability within immersion (Irish medium) schools. Some introduce Irish reading first (IRF) and others English reading first (ERF). This study compared the development of Irish and English skills in children attending…

Working Memory Arrest in Children with High-Functioning Autism Compared to Children with Attention-Deficit/Hyperactivity Disorder: Results from a 2-Year Longitudinal Study

ERIC Educational Resources Information Center

Andersen, Per N.; Skogli, Erik W.; Hovik, Kjell T.; Geurts, Hilde; Egeland, Jens; Øie, Merete

2015-01-01

The aim of this study was to analyse the development of verbal working memory in children with high-functioning autism compared to children with attention-deficit/hyperactivity disorder and typically developing children. A total of 34 children with high-functioning autism, 72 children with attention-deficit/hyperactivity disorder and 45 typically…

Transversely polarized source cladding for an optical fiber

NASA Technical Reports Server (NTRS)

Egalon, Claudio Oliveira (Inventor); Rogowski, Robert S. (Inventor)

1994-01-01

An optical fiber comprising a fiber core having a longitudinal symmetry axis is provided. An active cladding surrounds a portion of the fiber core and comprises light-producing sources which emit light in response to chemical or light excitation. The cladding sources are oriented transversely with respect to the longitudinal axis of the fiber core. This polarization results in a superior power efficiency compared to active cladding sources that are randomly polarized or longitudinally polarized parallel with the longitudinal symmetry axis.

Study of the heavy ion bunch compression in CSRm

NASA Astrophysics Data System (ADS)

Yin, Da-Yu; Liu, Yong; Yuan, You-Jing; Yang, Jian-Cheng; Li, Peng; Li, Jie; Chai, Wei-Ping; Sha, Xiao-Ping

2013-05-01

The feasibility of attaining nanosecond pulse length heavy ion beam is studied in the main ring (CSRm) of the Heavy Ion Research Facility in Lanzhou. Such heavy ion beam can be produced by non-adiabatic compression, and it is implemented by a fast rotation in the longitudinal phase space. In this paper, the possible beam parameters during longitudinal bunch compression are studied with the envelope model and Particle in Cell simulation, and the results are compared. The result shows that the short bunch 238U28+ with the pulse duration of about 50 ns at the energy of 200 MeV/u can be obtained which can satisfy the research of high density plasma physics experiment.

Association analysis of whole genome sequencing data accounting for longitudinal and family designs.

PubMed

Hu, Yijuan; Hui, Qin; Sun, Yan V

2014-01-01

Using the whole genome sequencing data and the simulated longitudinal phenotypes for 849 pedigree-based individuals from Genetic Analysis Workshop 18, we investigated various approaches to detecting the association of rare and common variants with blood pressure traits. We compared three strategies for longitudinal data: (a) using the baseline measurement only, (b) using the average from multiple visits, and (c) using all individual measurements. We also compared the power of using all of the pedigree-based data and the unrelated subset. The analyses were performed without knowledge of the underlying simulating model.

76 FR 1621 - Proposed Collection; Comment Request; NIH Toolbox for Assessment of Neurological and Behavioral...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-11

..., emotional, motor and sensory) for use in large longitudinal or epidemiological studies where functioning is... of establishing comparative norms. Existing recruitment databases will be randomly sampled and... * Adult study participants, single assessment..... 3,150 1 3 9,450 Adult study participants, two...

Clustering of longitudinal data by using an extended baseline: A new method for treatment efficacy clustering in longitudinal data.

PubMed

Schramm, Catherine; Vial, Céline; Bachoud-Lévi, Anne-Catherine; Katsahian, Sandrine

2018-01-01

Heterogeneity in treatment efficacy is a major concern in clinical trials. Clustering may help to identify the treatment responders and the non-responders. In the context of longitudinal cluster analyses, sample size and variability of the times of measurements are the main issues with the current methods. Here, we propose a new two-step method for the Clustering of Longitudinal data by using an Extended Baseline. The first step relies on a piecewise linear mixed model for repeated measurements with a treatment-time interaction. The second step clusters the random predictions and considers several parametric (model-based) and non-parametric (partitioning, ascendant hierarchical clustering) algorithms. A simulation study compares all options of the clustering of longitudinal data by using an extended baseline method with the latent-class mixed model. The clustering of longitudinal data by using an extended baseline method with the two model-based algorithms was the more robust model. The clustering of longitudinal data by using an extended baseline method with all the non-parametric algorithms failed when there were unequal variances of treatment effect between clusters or when the subgroups had unbalanced sample sizes. The latent-class mixed model failed when the between-patients slope variability is high. Two real data sets on neurodegenerative disease and on obesity illustrate the clustering of longitudinal data by using an extended baseline method and show how clustering may help to identify the marker(s) of the treatment response. The application of the clustering of longitudinal data by using an extended baseline method in exploratory analysis as the first stage before setting up stratified designs can provide a better estimation of treatment effect in future clinical trials.

Integrating prospective longitudinal data: modeling personality and health in the Terman Life Cycle and Hawaii Longitudinal Studies.

PubMed

Kern, Margaret L; Hampson, Sarah E; Goldberg, Lewis R; Friedman, Howard S

2014-05-01

The present study used a collaborative framework to integrate 2 long-term prospective studies: the Terman Life Cycle Study and the Hawaii Personality and Health Longitudinal Study. Within a 5-factor personality-trait framework, teacher assessments of child personality were rationally and empirically aligned to establish similar factor structures across samples. Comparable items related to adult self-rated health, education, and alcohol use were harmonized, and data were pooled on harmonized items. A structural model was estimated as a multigroup analysis. Harmonized child personality factors were then used to examine markers of physiological dysfunction in the Hawaii sample and mortality risk in the Terman sample. Harmonized conscientiousness predicted less physiological dysfunction in the Hawaii sample and lower mortality risk in the Terman sample. These results illustrate how collaborative, integrative work with multiple samples offers the exciting possibility that samples from different cohorts and ages can be linked together to directly test life span theories of personality and health. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

Multivariate longitudinal data analysis with censored and intermittent missing responses.

PubMed

Lin, Tsung-I; Lachos, Victor H; Wang, Wan-Lun

2018-05-08

The multivariate linear mixed model (MLMM) has emerged as an important analytical tool for longitudinal data with multiple outcomes. However, the analysis of multivariate longitudinal data could be complicated by the presence of censored measurements because of a detection limit of the assay in combination with unavoidable missing values arising when subjects miss some of their scheduled visits intermittently. This paper presents a generalization of the MLMM approach, called the MLMM-CM, for a joint analysis of the multivariate longitudinal data with censored and intermittent missing responses. A computationally feasible expectation maximization-based procedure is developed to carry out maximum likelihood estimation within the MLMM-CM framework. Moreover, the asymptotic standard errors of fixed effects are explicitly obtained via the information-based method. We illustrate our methodology by using simulated data and a case study from an AIDS clinical trial. Experimental results reveal that the proposed method is able to provide more satisfactory performance as compared with the traditional MLMM approach. Copyright © 2018 John Wiley & Sons, Ltd.

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

PubMed

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

2015-10-28

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

Transesophageal Echocardiography, 3-Dimensional and Speckle Tracking Together as Sensitive Markers for Early Outcome in Patients With Left Ventricular Dysfunction Undergoing Cardiac Surgery.

PubMed

Kumar, Alok; Puri, Goverdhan Dutt; Bahl, Ajay

2017-10-01

Speckle tracking, when combined with 3-dimensional (3D) left ventricular ejection fraction, might prove to be a more sensitive marker for postoperative ventricular dysfunction. This study investigated early outcomes in a cohort of patients with left ventricular dysfunction undergoing cardiac surgery. Prospective, blinded, observational study. University hospital; single institution. The study comprised 73 adult patients with left ventricular ejection fraction <50% undergoing cardiac surgery using cardiopulmonary bypass. Routine transesophageal echocardiography before and after bypass. Global longitudinal strain using speckle tracking and 3D left ventricular ejection fraction were computed using transesophageal echocardiography. Mean prebypass global longitudinal strain and 3D left ventricle ejection fraction were significantly lower in patients with postoperative low-cardiac-output syndrome compared with patients who did not develop low cardiac output (global longitudinal strain -7.5% v -10.7% and 3D left ventricular ejection fraction 29% v 39%, respectively; p < 0.0001). The cut-off value of global longitudinal strain predicting postoperative low-cardiac-output syndrome was -6%, with 95% sensitivity and 68% specificity; and 3D left ventricular ejection fraction was 19% with 98% sensitivity and 81% specificity. Preoperative left ventricular global longitudinal strain (-6%) and 3D left ventricular ejection fraction (19%) together could act as predictor of postoperative low-cardiac-output states with high sensitivity (99.9%) in patients undergoing cardiac surgery. Copyright © 2017 Elsevier Inc. All rights reserved.

A Longitudinal Study of the Six Degrees of Freedom Cervical Spine Range of Motion During Dynamic Flexion/Extension and Rotation After Single-Level Anterior Arthrodesis

PubMed Central

Anderst, William J.; West, Tyler; Donaldson, William F; Lee, Joon Y.; Kang, James D.

2016-01-01

Study Design A longitudinal study using biplane radiography to measure in vivo intervertebral range of motion (ROM) during dynamic flexion/extension and rotation. Objective To longitudinally compare intervertebral maximal ROM and midrange motion in asymptomatic control subjects and single-level arthrodesis patients. Summary of Background Data In vitro studies consistently report that adjacent segment maximal ROM increases superior and inferior to cervical arthrodesis. Previous in vivo results have been conflicting, indicating that maximal ROM may or may not increase superior and/or inferior to the arthrodesis. There are no previous reports of midrange motion in arthrodesis patients and similar-aged controls. Methods Eight single-level (C5/C6) anterior arthrodesis patients (tested 7±1 months and 28±6 months post-surgery) and six asymptomatic control subjects (tested twice, 58±6 months apart) performed dynamic full ROM flexion/extension and axial rotation while biplane radiographs were collected at 30 images/s. A previously validated tracking process determined three-dimensional vertebral position from each pair of radiographs with sub-millimeter accuracy. The intervertebral maximal ROM and midrange motion in flexion/extension, rotation, lateral bending, and anterior-posterior translation were compared between test dates and between groups. Results Adjacent segment maximal ROM did not increase over time during flexion/extension or rotation movements. Adjacent segment maximal rotational ROM was not significantly greater in arthrodesis patients than in corresponding motion segments of similar-aged controls. C4/C5 adjacent segment rotation during the midrange of head motion and maximal anterior-posterior translation were significantly greater in arthrodesis patients than in the corresponding motion segment in controls on the second test date. Conclusions C5/C6 arthrodesis appears to significantly affect midrange, but not end-range, adjacent segment motions. The effects of arthrodesis on adjacent segment motion may be best evaluated by longitudinal studies that compare maximal and midrange adjacent segment motion to corresponding motion segments of similar-aged controls to determine if the adjacent segment motion is truly excessive. PMID:27831986

Porcine lens nuclei as a model for comparison of 3 ultrasound modalities regarding efficiency and chatter.

PubMed

Oakey, Zack B; Jensen, Jason D; Zaugg, Brian E; Radmall, Bryce R; Pettey, Jeff H; Olson, Randall J

2013-08-01

To validate a porcine lens model by comparing density and ultrasound (US) with known human standards using the Infiniti Ozil with Intelligent Phacoemulsification (torsional), Whitestar Signature Micropulse (longitudinal), and Ellips FX (transversal) modalities. Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. Experimental study. Lens nuclei were formalin soaked in hour-based intervals and divided into 2.0 mm cubes. Density was characterized by crushing experiments and compared with known human measures. Efficiency and chatter were examined. The mean weight to cut thickness in half ranged from 16.9 g ± 5.5 (SD) in the 0-hour group to 121.3 ± 47.5 gm in the 4-hour group. Lenses in the 2-hour group (mean 70.2 ± 19.1 g) best matched human density (P=.215). The mean efficiency ranged from 0.432 ± 0.178 seconds to 9.111 ± 2.925 seconds; chatter ranged from zero to 1.85 ± 1.927 bounces. No significant difference was detected when comparing the 2-hour formalin group with human lenses in torsional and transversal US. There was no significant difference between transversal and torsional modalities, consistent with human studies. Although longitudinal (6 milliseconds on, 12 milliseconds off) was significantly more efficient at 50% power than at 25%, there was no significant difference compared with transversal or torsional US. Animal lenses soaked for 2 hours in formalin were most comparable to human lenses. Longitudinal US may be an acceptable alternative to torsional and transversal US. Copyright © 2013 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

The New York City Infant Day Care Study: A Comparative Study of Licensed Group and Family Infant Day Care Programs and the Effects of These Programs on Children and Their Families. Final Report.

ERIC Educational Resources Information Center

New York City Dept. of Health, NY.

This paper describes a longitudinal comparative study of group and family day care for infants in New York City. Approximately 400 infants from low income, predominantly Black or Hispanic families enrolled in publicly or privately funded, community-sponsored day care programs participated in the study from the time they entered the programs…

The ONS Longitudinal Study--a prestigious past and a bright future.

PubMed

Goldring, Shayla; Newman, Jim

2010-01-01

This issue of Population Trends includes a number of articles and reports resulting from research based on the ONS Longitudinal Study (ONS LS). They have been drawn together in one issue to highlight the value of this type of study for demographic research.2009 marked the 35th anniversary of the establishment of the ONS LS. The study now contains data from the last four censuses (1971 to 2001), linked to vital events data since 1971, for a sample of one per cent of the population of England and Wales.More recently, sister studies have been established in Scotland and Northern Ireland. The Scottish Longitudinal Study (SLS) started with 1991 Census data and the Northern Ireland Longitudinal Study (NILS)started with 2001 Census data.The lead article in this issue comes from an exemplar project that was established to explore how to utilise the three studies to carry out UK-wide longitudinal analysis. Two different methods were used to analyse socio-economic and country level differences in health and mortality across the studies. The article summarises the results of this analysis, reports on the relative strengths of the different methods used, and draws attention to a number of new resources that have been developed by the project researchers as aids to using all three studies.This is an excellent example of collaborative working across the UK, involving researchers from the Centre for Longitudinal Study Information and User Support (CeLSIUS) at the London School of Hygiene and Tropical Medicine, the Longitudinal Studies Centre - Scotland (LSCS) at the University of St.Andrews and the Northern Ireland Longitudinal Study - Research Support Unit (NILS-RSU) at Queen's University Belfast. The project also involved collaboration between ONS, the General Register Office for Scotland (GROS) and the Northern Ireland Statistics and Research Agency (NISRA) to ensure the secure transfer and handling of data from the three studies so that it could be brought together in one place for analysis.The other ONS LS-based articles and reports in this edition largely focus on research into issues related to families and households, as summarised below: A collaborative project involving Ben Wilson (ONS) and Rachel Stuchbury (CeLSIUS) comparing the stability of partnerships involving marriage and cohabitation.A project looking at transitions in children's experience of living in a workless household and how this varies by ethnic group, submitted by Lucinda Platt (Institute for Social & Economic Research, University of Essex).An article on the effect of a change in the census definition of a child between 1991 and 2001 submitted by Emily Grundy, Rachel Stuchbury and Harriet Young (CeLSIUS).The remainder of this introductory article will focus on the ONS LS, its history and some examples of its use, and gives a summary of planned developments over the coming years. Please refer to the contact details at the end of the article if you require further information on any of the three longitudinal studies.

Seasonal variation of strongylosis in working donkeys of Ethiopia: a cross-sectional and longitudinal studies.

PubMed

Dibaba, Motuma Debelo; Getachew, A M; Assefa, Zerihun; Fanta, Alemayehu; Etana, Manyahilishal; Firew, Seyoum; Goshu, Lemessa; Burden, F

2017-07-01

Helminths are one of the major health problems of working donkeys, often with heavy worm burden and contributing to their early demise and/or reduction in their work output. Cross-sectional and longitudinal studies were conducted to investigate the current infection prevalence and level of strongyles infection donkeys would acquire through different seasons in the mid-lowland agro-ecological zones of Ethiopia. For this purpose, faecal samples from 206 (cross-sectional study) and 102 (longitudinal study) randomly selected donkeys were directly collected from the rectum and analysed. For the longitudinal study, the 102 donkeys dewormed at the end of main rainy season, beginning of October, were monitored for the level of strongyle infection they would acquire during subsequent dry and short rainy seasons. The cross-sectional study of 206 donkey has revealed an overall infection prevalence of 89.3% (95% confidence interval (CI) = 84.4, 92.9). Donkeys in the lowland zone showed a significantly higher strongyle infection prevalence (P = 0.0126) and mean eggs per gramme of faces (EPG) (P = 0.001; 2775 EPG) compared to donkeys in the midland zone (980.8 EPG). Age, sex and body condition did not have any significant effect on either the infection prevalence or level of infection (P > 0.05). The longitudinal study has shown a significantly lower strongyle infection prevalence (P = 0.003) and level of infection donkeys acquired (P = 0.001) in the subsequent dry and short rainy seasons compared to the main rainy season following October deworming. However, these values were not significantly different between the two agro-ecological zones (P > 0.05). This study clearly showed that parasitic infections are primarily acquired during the main rainy season when pasture/herbage coverage is relatively better, and the environment is conducive for parasites survival and development. On the other hand, the finding of majority of donkeys shedding low or no eggs during the dry and short rainy seasons showed that October deworming was effective, and donkeys acquire low or no parasitic infection during the subsequent dry and short rainy seasons. Therefore, the practice of anthelmintic treatment of donkeys at the end of short rain in May may not be necessary, and October deworming once a year is sufficient.

Association between Arsenic Exposure from Drinking Water and Longitudinal Change in Blood Pressure among HEALS Cohort Participants.

PubMed

Jiang, Jieying; Liu, Mengling; Parvez, Faruque; Wang, Binhuan; Wu, Fen; Eunus, Mahbub; Bangalore, Sripal; Newman, Jonathan D; Ahmed, Alauddin; Islam, Tariqul; Rakibuz-Zaman, Muhammad; Hasan, Rabiul; Sarwar, Golam; Levy, Diane; Slavkovich, Vesna; Argos, Maria; Scannell Bryan, Molly; Farzan, Shohreh F; Hayes, Richard B; Graziano, Joseph H; Ahsan, Habibul; Chen, Yu

2015-08-01

Cross-sectional studies have shown associations between arsenic exposure and prevalence of high blood pressure; however, studies examining the relationship of arsenic exposure with longitudinal changes in blood pressure are lacking. We evaluated associations of arsenic exposure in relation to longitudinal change in blood pressure in 10,853 participants in the Health Effects of Arsenic Longitudinal Study (HEALS). Arsenic was measured in well water and in urine samples at baseline and in urine samples every 2 years after baseline. Mixed-effect models were used to estimate the association of baseline well and urinary creatinine-adjusted arsenic with annual change in blood pressure during follow-up (median, 6.7 years). In the HEALS population, the median water arsenic concentration at baseline was 62 μg/L. Individuals in the highest quartile of baseline water arsenic or urinary creatinine-adjusted arsenic had a greater annual increase in systolic blood pressure compared with those in the reference group (β = 0.48 mmHg/year; 95% CI: 0.35, 0.61, and β = 0.43 mmHg/year; 95% CI: 0.29, 0.56 for water arsenic and urinary creatinine-adjusted arsenic, respectively) in fully adjusted models. Likewise, individuals in the highest quartile of baseline arsenic exposure had a greater annual increase in diastolic blood pressure for water arsenic and urinary creatinine-adjusted arsenic, (β = 0.39 mmHg/year; 95% CI: 0.30, 0.49, and β = 0.45 mmHg/year; 95% CI: 0.36, 0.55, respectively) compared with those in the lowest quartile. Our findings suggest that long-term arsenic exposure may accelerate age-related increases in blood pressure. These findings may help explain associations between arsenic exposure and cardiovascular disease.

Growth trajectories in the children of mothers with eating disorders: a longitudinal study

PubMed Central

Easter, Abigail; Howe, Laura D; Tilling, Kate; Schmidt, Ulrike; Treasure, Janet; Micali, Nadia

2014-01-01

Objective The aim of this study was to examine longitudinal patterns of growth trajectories in children of women with eating disorders (ED): anorexia nervosa (AN) and bulimia nervosa (BN). Design Prospective longitudinal birth cohort; Avon Longitudinal Study of Parents and Children (ALSPAC). Setting South West England, UK. Participants The sample consisted of women and their children (n=10 190) from ALSPAC. Patterns of growth among children of women reporting a history of AN (n=137), BN (n=165), both AN and BN (n=68) and other psychiatric disorders (n=920) were compared with an unexposed group of children (n=8900). Main outcome measures Height and weight data, from birth to 10 years, were extracted from health visitor records, parental report from questionnaires and clinic attendances. Growth trajectories were analysed using mixed-effects models and constructed separately for male and female children. Results Between birth and 10 years, male children of women with BN were taller than children in the unexposed group. Male children of women with a history of AN and BN, and female children of women with AN, were shorter throughout childhood. Between the ages of 2 and 5, higher body mass index (BMI) was observed in male children in all maternal ED groups. Conversely, female children of women with AN had a BMI of −0.35 kg/m2 lower at 2 years compared with the unexposed group, with catch-up by age 10. Conclusions Early childhood growth has been found to predict weight gain in adolescence and adulthood, and may be a risk factor for the development of an ED. These findings therefore have public health implications in relation to the prevention of weight-related and eating-related disorders later in life. PMID:24674996

Growth trajectories in the children of mothers with eating disorders: a longitudinal study.

PubMed

Easter, Abigail; Howe, Laura D; Tilling, Kate; Schmidt, Ulrike; Treasure, Janet; Micali, Nadia

2014-03-27

The aim of this study was to examine longitudinal patterns of growth trajectories in children of women with eating disorders (ED): anorexia nervosa (AN) and bulimia nervosa (BN). Prospective longitudinal birth cohort; Avon Longitudinal Study of Parents and Children (ALSPAC). South West England, UK. The sample consisted of women and their children (n=10 190) from ALSPAC. Patterns of growth among children of women reporting a history of AN (n=137), BN (n=165), both AN and BN (n=68) and other psychiatric disorders (n=920) were compared with an unexposed group of children (n=8900). Height and weight data, from birth to 10 years, were extracted from health visitor records, parental report from questionnaires and clinic attendances. Growth trajectories were analysed using mixed-effects models and constructed separately for male and female children. Between birth and 10 years, male children of women with BN were taller than children in the unexposed group. Male children of women with a history of AN and BN, and female children of women with AN, were shorter throughout childhood. Between the ages of 2 and 5, higher body mass index (BMI) was observed in male children in all maternal ED groups. Conversely, female children of women with AN had a BMI of -0.35 kg/m(2) lower at 2 years compared with the unexposed group, with catch-up by age 10. Early childhood growth has been found to predict weight gain in adolescence and adulthood, and may be a risk factor for the development of an ED. These findings therefore have public health implications in relation to the prevention of weight-related and eating-related disorders later in life.

Smoking During Adolescence as a Risk Factor for Attention Problems.

PubMed

Treur, Jorien L; Willemsen, Gonneke; Bartels, Meike; Geels, Lot M; van Beek, Jenny H D A; Huppertz, Charlotte; van Beijsterveldt, Catharina E M; Boomsma, Dorret I; Vink, Jacqueline M

2015-11-01

Cigarette smoking and attention-deficit/hyperactivity disorder (ADHD) are highly comorbid. One explanation is that individuals with ADHD use cigarettes as "self-medication" to alleviate their attention problems. However, animal studies reported that exposure to nicotine during adolescence influences the developing brain and negatively affects attention. This is the first human study exploring the effects of smoking during adolescence on attention problems. Longitudinal data on smoking and attention problems were available for 1987 adult and 648 adolescent monozygotic twin pairs from the Netherlands Twin Register. Twin pairs were classified as concordant/discordant for smoking and compared on attention problems. Within adult discordant pairs, the difference in attention problems between the smoking and never-smoking twins was first assessed cross-sectionally. In longitudinal analyses, the increase in attention problems from adolescence, when neither twin smoked, to adulthood was compared within discordant pairs. In subgroups with longitudinal data from childhood and adolescence, changes in smoking concordance and subsequent changes in attention problems were explored. Adult twins who ever smoked reported significantly more attention problems than their never-smoking co-twin. Longitudinal analyses showed a larger increase in attention problems from adolescence to adulthood in smoking twins than their never-smoking co-twin (p < .05). In childhood and adolescence, smoking twins had more attention problems than their never-smoking co-twin, whereas scores were similar before smoking was initiated or after both twins started smoking (not significant in all groups). Results from this genetically informative study suggest smoking during adolescence leads to higher attention problem scores, lasting into adulthood. Copyright © 2015 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Psychiatric Disorders and General Functioning in Low Birth Weight Adults: A Longitudinal Study.

PubMed

Lærum, Astrid M W; Reitan, Solveig Klæbo; Evensen, Kari Anne I; Lydersen, Stian; Brubakk, Ann-Mari; Skranes, Jon; Indredavik, Marit S

2017-02-01

To examine psychiatric morbidity and overall functioning in adults born with low birth weight compared with normal birth weight controls at age 26 years and to study longitudinal trajectories of psychiatric morbidity from early adolescence to adulthood. Prospective cohort study wherein 44 preterm very low birth weight (≤1500 g), 64 term small for gestational age (SGA; <10th percentile), and 81 control adults were examined using the MINI-International Neuropsychiatric Interview: M.I.N.I. Plus, Norwegian version, the Global Assessment of Functioning, and questions on daily occupation and level of education. Prevalence of psychiatric disorders from previous follow-ups at age 14 and 19 years were included for longitudinal analysis. From adolescence to adulthood, the term SGA group had a marked increase in the estimated probability of psychiatric disorders from 9% (95% confidence interval, 4-19) to 39% (95% confidence interval, 28-51). At 26 years, psychiatric diagnoses were significantly more prevalent in the preterm very low birth weight group (n = 16, 36%; P = .003) and the term SGA group (n = 24, 38%; P = .019) compared with the control group (n = 11, 14%). Both low birth weight groups had lower educational level and functioning scores than controls and a higher frequency of unemployment and disability benefit. Low birth weight was a substantial risk factor for adult psychiatric morbidity and lowered overall functioning. The results underscore the need for long-term follow-up of low birth weight survivors through adolescence and adulthood, focusing on mental health. The longitudinal increase in psychiatric morbidity in the term SGA group calls for additional investigation. Copyright © 2017 by the American Academy of Pediatrics.

A longitudinal study of changes in noticing and treating patients' overweight by Dutch GPs between 1997 and 2007.

PubMed

van Dijk, Elske; Kampen, Jarl K; Hiddink, Gerrit J; Renes, Reint Jan; van Binsbergen, Jaap J; van Woerkum, Cees M J

2012-04-01

One of the stakeholders in tackling the rise and health consequences of overweight and obesity is the general practice physician (GP). GPs are in a good position to inform and give nutrition guidance to overweight patients. Assessment of working mechanism of determinants of the nutrition guidance practice: noticing patients' overweight and guidance of treatment by GPs [linear analysis of structural relations (LISREL) path model] in a longitudinal study. This longitudinal study measured data in 1992, 1997 and 2007. The 1992 LISREL path model (Hiddink GJ, Hautvast J, van Woerkum CMJ, Fieren CJ, van t'Hof MA. Nutrition guidance by primary-care physicians: LISREL analysis improves understanding. Prev Med 1997; 26: 29-36.) demonstrated that 'noticing patients' overweight and guidance of treatment' was directly and indirectly influenced by predisposing factors, driving forces and perceived barriers. This article defines and discusses the path analysis of the 2007 data (compared with 1997). This analysis shows both similarity and differences in working mechanism of determinants of noticing patients' overweight and guidance of treatment between 1997 and 2007. The backbone of the mechanism with four predisposing factors is the similarity. The number of driving forces and of paths through intermediary factors to the dependent variable constitutes the difference. The backbone of the working mechanism of determinants of the nutrition guidance practice: noticing patients' overweight and guidance of treatment by GPs was similar in 2007 and 1997. The influence of GPs task perception on noticing patients' overweight and guidance of treatment considerably increased in 2007 compared to 1997. The longitudinal character of this article gives a strong practice-based evidence for weight management by GPs.

Measuring vascular reactivity with breath-holds after stroke: a method to aid interpretation of group-level BOLD signal changes in longitudinal fMRI studies.

PubMed

Geranmayeh, Fatemeh; Wise, Richard J S; Leech, Robert; Murphy, Kevin

2015-05-01

Blood oxygenation level-dependent (BOLD) contrast functional magnetic resonance imaging (fMRI) is a widely used technique to map brain function, and to monitor its recovery after stroke. Since stroke has a vascular etiology, the neurovascular coupling between cerebral blood flow and neural activity may be altered, resulting in uncertainties when interpreting longitudinal BOLD signal changes. The purpose of this study was to demonstrate the feasibility of using a recently validated breath-hold task in patients with stroke, both to assess group level changes in cerebrovascular reactivity (CVR) and to determine if alterations in regional CVR over time will adversely affect interpretation of task-related BOLD signal changes. Three methods of analyzing the breath-hold data were evaluated. The CVR measures were compared over healthy tissue, infarcted tissue and the peri-infarct tissue, both sub-acutely (∼2 weeks) and chronically (∼4 months). In this cohort, a lack of CVR differences in healthy tissue between the patients and controls indicates that any group level BOLD signal change observed in these regions over time is unlikely to be related to vascular alterations. CVR was reduced in the peri-infarct tissue but remained unchanged over time. Therefore, although a lack of activation in this region compared with the controls may be confounded by a reduced CVR, longitudinal group-level BOLD changes may be more confidently attributed to neural activity changes in this cohort. By including this breath-hold-based CVR assessment protocol in future studies of stroke recovery, researchers can be more assured that longitudinal changes in BOLD signal reflect true alterations in neural activity. © 2015 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

Long-term Characterization of Retinal Degeneration in Royal College of Surgeons Rats Using Spectral-Domain Optical Coherence Tomography

PubMed Central

Ryals, Renee C.; Andrews, Michael D.; Datta, Shreya; Coyner, Aaron S.; Fischer, Cody M.; Wen, Yuquan; Pennesi, Mark E.; McGill, Trevor J.

2017-01-01

Purpose Prospective treatments for age-related macular degeneration and inherited retinal degenerations are commonly evaluated in the Royal College of Surgeons (RCS) rat before translation into clinical application. Historically, retinal thickness obtained through postmortem anatomic assessments has been a key outcome measure; however, utility of this measurement is limited because it precludes the ability to perform longitudinal studies. To overcome this limitation, the present study was designed to provide a baseline longitudinal quantification of retinal thickness in the RCS rat by using spectral-domain optical coherence tomography (SD-OCT). Methods Horizontal and vertical linear SD-OCT scans centered on the optic nerve were captured from Long-Evans control rats at P30, P60, P90 and from RCS rats between P17 and P90. Total retina (TR), outer nuclear layer+ (ONL+), inner nuclear layer (INL), and retinal pigment epithelium (RPE) thicknesses were quantified. Histologic sections of RCS retina obtained from P21 to P60 were compared to SD-OCT images. Results In RCS rats, TR and ONL+ thickness decreased significantly as compared to Long-Evans controls. Changes in INL and RPE thickness were not significantly different between control and RCS retinas. From P30 to P90 a subretinal hyperreflective layer (HRL) was observed and quantified in RCS rats. After correlation with histology, the HRL was identified as disorganized outer segments and the location of accumulated debris. Conclusions Retinal layer thickness can be quantified longitudinally throughout the course of retinal degeneration in the RCS rat by using SD-OCT. Thickness measurements obtained with SD-OCT were consistent with previous anatomic thickness assessments. This study provides baseline data for future longitudinal assessment of therapeutic agents in the RCS rat. PMID:28253400

Long-term Characterization of Retinal Degeneration in Royal College of Surgeons Rats Using Spectral-Domain Optical Coherence Tomography.

PubMed

Ryals, Renee C; Andrews, Michael D; Datta, Shreya; Coyner, Aaron S; Fischer, Cody M; Wen, Yuquan; Pennesi, Mark E; McGill, Trevor J

2017-03-01

Prospective treatments for age-related macular degeneration and inherited retinal degenerations are commonly evaluated in the Royal College of Surgeons (RCS) rat before translation into clinical application. Historically, retinal thickness obtained through postmortem anatomic assessments has been a key outcome measure; however, utility of this measurement is limited because it precludes the ability to perform longitudinal studies. To overcome this limitation, the present study was designed to provide a baseline longitudinal quantification of retinal thickness in the RCS rat by using spectral-domain optical coherence tomography (SD-OCT). Horizontal and vertical linear SD-OCT scans centered on the optic nerve were captured from Long-Evans control rats at P30, P60, P90 and from RCS rats between P17 and P90. Total retina (TR), outer nuclear layer+ (ONL+), inner nuclear layer (INL), and retinal pigment epithelium (RPE) thicknesses were quantified. Histologic sections of RCS retina obtained from P21 to P60 were compared to SD-OCT images. In RCS rats, TR and ONL+ thickness decreased significantly as compared to Long-Evans controls. Changes in INL and RPE thickness were not significantly different between control and RCS retinas. From P30 to P90 a subretinal hyperreflective layer (HRL) was observed and quantified in RCS rats. After correlation with histology, the HRL was identified as disorganized outer segments and the location of accumulated debris. Retinal layer thickness can be quantified longitudinally throughout the course of retinal degeneration in the RCS rat by using SD-OCT. Thickness measurements obtained with SD-OCT were consistent with previous anatomic thickness assessments. This study provides baseline data for future longitudinal assessment of therapeutic agents in the RCS rat.

Cardiovascular Disease Risk in NASA Astronauts Across the Lifespan: Historical Cohort Studies

NASA Technical Reports Server (NTRS)

Charvat, Jacqueline M.; Lee, Stuart M. C.; Davenport, Eddie; Barlow, Carolyn E.; Radford, Nina B.; De Fina, Laura F.; Stenger, Michael B.; Van Baalen, Mary

2017-01-01

Acute effects of spaceflight on the cardiovascular system have been studied extensively, but the combined chronic effects of spaceflight and aging are not well understood. Preparation for and participation in space flight activities are potentially associated with cardiovascular disease risk factors (e.g., altered dietary and exercise habits, physical and emotional stress, circadian shifts, radiation). Further, astronauts who travel into space multiple times may be at an increased risk across their lifespan. However, comparing the risk of cardiovascular disease in astronauts to other large cohorts is difficult. For example, comparisons between astronauts and large national cohorts, such as the National Health and Nutrition Examination Survey and the National Health Information Survey, are hampered by significant differences in health status between astronauts and the general population, and most of these national studies fail to provide longitudinal data on population health. To address those limitations, NASA's Longitudinal Study of Astronaut Health previously sought to compare the astronauts to a cohort of civil servants employed at the Johnson Space Center. However, differences between the astronauts and civil servants at the beginning of the study, as well as differential follow up, limited the ability to interpret the results. To resolve some of these limitations, two unique cohorts of healthy workers, U.S. Air Force aviators and Cooper Center Longitudinal Study participants, have been identified as potential comparison populations for the astronaut corps. The Air Force cohort was chosen due to similarities in health at selection, screening, and some occupational exposures that Air Force aviators endure, many of which mirror that of the astronaut corps. The Cooper Clinic cohort, a generally healthy prevention cohort, was chosen for the vast array of clinical cardiovascular measures collected in a longitudinal manner complementary to those collected on astronauts, for a large number of subjects since 1971. The purpose of this study is to understand the incidence of cardiovascular disease outcomes and risk factors in the astronaut corps and determine whether the rates of disease are different than these two cohorts. The research questions are: 1. Are there differences in the incidence of CVD outcomes (MI, revascularization, and stroke) between each cohort and the NASA Astronaut cohort? 2. Are there differences in the incidence of CVD risks (hypertension, hyperlipidemia, arrhythmias, and diabetes) between each cohort and the NASA Astronaut cohort? 3. Are there differences between each cohort and the NASA Astronaut cohort in how CVD risk factors (e.g., lipids, behaviors) change across time? Collectively, results from these studies will enhance our understanding of how cardiovascular disease outcomes and risk factors change across time in astronauts compared to other longitudinally-studied healthy cohorts and determine if there are interactions between or additive effects of the occupational health effects of spaceflight exposure and normal aging.

Declining brain glucose metabolism in normal individuals with a maternal history of Alzheimer disease.

PubMed

Mosconi, L; Mistur, R; Switalski, R; Brys, M; Glodzik, L; Rich, K; Pirraglia, E; Tsui, W; De Santi, S; de Leon, M J

2009-02-10

At cross-section, cognitively normal individuals (NL) with a maternal history of late-onset Alzheimer disease (AD) have reduced glucose metabolism (CMRglc) on FDG-PET in the same brain regions as patients with clinical AD as compared to those with a paternal and a negative family history (FH) of AD. This longitudinal FDG-PET study examines whether CMRglc reductions in NL subjects with a maternal history of AD are progressive. Seventy-five 50- to 82-year-old NL received 2-year follow-up clinical, neuropsychological, and FDG-PET examinations. These included 37 subjects with negative family history of AD (FH-), 9 with paternal (FHp), and 20 with maternal AD (FHm). Two subjects had parents with postmortem confirmed AD. Statistical parametric mapping was used to compare CMRglc across FH groups at baseline, follow-up, and longitudinally. At both time points, the FH groups were comparable for demographic and neuropsychological characteristics. At baseline and at follow-up, FHm subjects showed CMRglc reductions in the parieto-temporal, posterior cingulate, and medial temporal cortices as compared to FH- and FHp (p < 0.001). Longitudinally, FHm had significant CMRglc declines in these regions, which were significantly greater than those in FH- and FHp (p < 0.05). A maternal history of Alzheimer disease (AD) predisposes normal individuals to progressive CMRglc reductions in AD-vulnerable brain regions, which may be related to a higher risk for developing AD.

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

Analytical and experimental studies on detection of longitudinal, L and inverted T cracks in isotropic and bi-material beams based on changes in natural frequencies

NASA Astrophysics Data System (ADS)

Ravi, J. T.; Nidhan, S.; Muthu, N.; Maiti, S. K.

2018-02-01

An analytical method for determination of dimensions of longitudinal crack in monolithic beams, based on frequency measurements, has been extended to model L and inverted T cracks. Such cracks including longitudinal crack arise in beams made of layered isotropic or composite materials. A new formulation for modelling cracks in bi-material beams is presented. Longitudinal crack segment sizes, for L and inverted T cracks, varying from 2.7% to 13.6% of length of Euler-Bernoulli beams are considered. Both forward and inverse problems have been examined. In the forward problems, the analytical results are compared with finite element (FE) solutions. In the inverse problems, the accuracy of prediction of crack dimensions is verified using FE results as input for virtual testing. The analytical results show good agreement with the actual crack dimensions. Further, experimental studies have been done to verify the accuracy of the analytical method for prediction of dimensions of three types of crack in isotropic and bi-material beams. The results show that the proposed formulation is reliable and can be employed for crack detection in slender beam like structures in practice.

Improved spatial regression analysis of diffusion tensor imaging for lesion detection during longitudinal progression of multiple sclerosis in individual subjects

NASA Astrophysics Data System (ADS)

Liu, Bilan; Qiu, Xing; Zhu, Tong; Tian, Wei; Hu, Rui; Ekholm, Sven; Schifitto, Giovanni; Zhong, Jianhui

2016-03-01

Subject-specific longitudinal DTI study is vital for investigation of pathological changes of lesions and disease evolution. Spatial Regression Analysis of Diffusion tensor imaging (SPREAD) is a non-parametric permutation-based statistical framework that combines spatial regression and resampling techniques to achieve effective detection of localized longitudinal diffusion changes within the whole brain at individual level without a priori hypotheses. However, boundary blurring and dislocation limit its sensitivity, especially towards detecting lesions of irregular shapes. In the present study, we propose an improved SPREAD (dubbed improved SPREAD, or iSPREAD) method by incorporating a three-dimensional (3D) nonlinear anisotropic diffusion filtering method, which provides edge-preserving image smoothing through a nonlinear scale space approach. The statistical inference based on iSPREAD was evaluated and compared with the original SPREAD method using both simulated and in vivo human brain data. Results demonstrated that the sensitivity and accuracy of the SPREAD method has been improved substantially by adapting nonlinear anisotropic filtering. iSPREAD identifies subject-specific longitudinal changes in the brain with improved sensitivity, accuracy, and enhanced statistical power, especially when the spatial correlation is heterogeneous among neighboring image pixels in DTI.

The effects of the Green House nursing home model on ADL function trajectory: A retrospective longitudinal study.

PubMed

Yoon, Ju Young; Brown, Roger L; Bowers, Barbara J; Sharkey, Siobhan S; Horn, Susan D

2016-01-01

Growing attention in the past few decades has focused on improving care quality and quality of life for nursing home residents. Many traditional nursing homes have attempted to transform themselves to become more homelike emphasizing individualized care. This trend is referred to as nursing home culture change in the U.S. A promising culture change nursing home model, the Green House nursing home model, has shown positive psychological outcomes. However, little is known about whether the Green House nursing home model has positive effects on physical function compared to traditional nursing homes. To examine the longitudinal effects of the Green House nursing home model by comparing change patterns of activities of daily living function over time between Green House home residents and traditional nursing home residents. A retrospective longitudinal study. Four Green House organizations (nine Green House units and four traditional units). A total of 242 residents (93 Green House residents and 149 traditional home residents) who had stayed in the nursing home at least 6 months from admission. The outcome was activities of daily living function, and the main independent variable was the facility type in which the resident stayed: a Green House or traditional unit. Age, gender, comorbidity score, cognitive function, and depressive symptoms at baseline were controlled. All of these measures were from a minimum dataset. Growth curve modeling and growth mixture modeling were employed in this study for longitudinal analyses. The mean activities of daily living function showed deterioration over time, and the rates of deterioration between Green House and traditional home residents were not different over time. Four different activities of daily living function trajectories were identified for 18 months, but there was no statistical difference in the likelihood of being in one of the four trajectory classes between the two groups. Although Green House nursing homes are considered to represent an innovative model changing the nursing home environment into more person-centered, this study did not demonstrate significant differences in activities of daily living function changes for residents in the Green House nursing homes compared to traditional nursing homes. Given that the Green House model continues to evolve as it is being implemented and variations within and across Green House homes are identified, large-scale longitudinal studies are needed to provide further relevant information on the effects of the Green House model. Copyright © 2015 Elsevier Ltd. All rights reserved.

Longitudinal Psychiatric Symptoms in Prodromal Huntington's Disease: A Decade of Data.

PubMed

Epping, Eric A; Kim, Ji-In; Craufurd, David; Brashers-Krug, Thomas M; Anderson, Karen E; McCusker, Elizabeth; Luther, Jolene; Long, Jeffrey D; Paulsen, Jane S

2016-02-01

Psychiatric symptoms are a significant aspect of Huntington's disease, an inherited neurodegenerative illness. The presentation of these symptoms is highly variable, and their course does not fully correlate with motor or cognitive disease progression. The authors sought to better understand the development and longitudinal course of psychiatric manifestations in individuals who carry the Huntington's disease mutation, starting from the prodromal period prior to motor diagnosis. Longitudinal measures for up to 10 years of psychiatric symptoms from the Symptom Checklist-90-Revised were obtained from 1,305 participants (1,007 carrying the Huntington's disease mutation and 298 without [classified as controls]) and 1,235 companions enrolled in the Neurobiological Predictors of Huntington's Disease (PREDICT-HD) study. Participants with the mutation were stratified into three groups according to probability of motor diagnosis within 5 years. Using linear mixed-effects regression models, differences in psychiatric symptoms at baseline and over time between the mutation-positive groups and the controls were compared, as well as between ratings by mutation-positive participants and their companions. Nineteen of 24 psychiatric measures (12 participant ratings and 12 companion ratings) were significantly higher at baseline and showed significant increases longitudinally in the individuals with the Huntington's disease mutation compared with controls. The differences were greatest in comparisons of symptom reports from companions compared with self-reports, especially in participants who were closest to motor diagnosis. The results indicate that psychiatric manifestations develop more often than previously thought in the Huntington's disease prodrome. Symptoms also increase with progression of disease severity. Greater symptom ratings by companions than by mutation-positive participants suggest decreasing awareness in those affected.

Lifetime eating disorder comorbidity associated with delayed depressive recovery in bipolar disorder.

PubMed

Balzafiore, Danielle R; Rasgon, Natalie L; Yuen, Laura D; Shah, Saloni; Kim, Hyun; Goffin, Kathryn C; Miller, Shefali; Wang, Po W; Ketter, Terence A

2017-12-01

Although eating disorders (EDs) are common in bipolar disorder (BD), little is known regarding their longitudinal consequences. We assessed prevalence, clinical correlates, and longitudinal depressive severity in BD patients with vs. without EDs. Outpatients referred to Stanford University BD Clinic during 2000-2011 were assessed with the Systematic Treatment Enhancement Program for BD (STEP-BD) affective disorders evaluation, and while receiving naturalistic treatment for up to 2 years, were monitored with the STEP-BD clinical monitoring form. Patients with vs. without lifetime EDs were compared with respect to prevalence, demographic and unfavorable illness characteristics/current mood symptoms and psychotropic use, and longitudinal depressive severity. Among 503 BD outpatients, 76 (15.1%) had lifetime EDs, which were associated with female gender, and higher rates of lifetime comorbid anxiety, alcohol/substance use, and personality disorders, childhood BD onset, episode accumulation (≥10 prior mood episodes), prior suicide attempt, current syndromal/subsyndromal depression, sadness, anxiety, and antidepressant use, and earlier BD onset age, and greater current overall BD severity. Among currently depressed patients, 29 with compared to 124 without lifetime EDs had significantly delayed depressive recovery. In contrast, among currently recovered (euthymic ≥8 weeks) patients, 10 with compared to 95 without lifetime EDs had only non-significantly hastened depressive recurrence. Primarily Caucasian, insured, suburban, American specialty clinic-referred sample limits generalizability. Small number of recovered patients with EDs limited statistical power to detect relationships between EDs and depressive recurrence. Further studies are warranted to explore the degree to which EDs impact longitudinal depressive illness burden in BD.

Results of endocapsular phacofracture debulking of hard cataracts

PubMed Central

Davison, James A

2015-01-01

Purpose/aim of the study To present a phacoemulsification technique for hard cataracts and compare postoperative results using two different ultrasonic tip motions during quadrant removal. Materials and methods A phacoemulsification technique which employs in situ fracture and endocapsular debulking for hard cataracts is presented. The prospective study included 56 consecutive cases of hard cataract (LOCS III NC [Lens Opacification Classification System III, nuclear color], average 4.26), which were operated using the Infiniti machine and the Partial Kelman tip. Longitudinal tip movement was used for sculpting for all cases which were randomized to receive longitudinal or torsional/interjected longitudinal (Intelligent Phaco [IP]) strategies for quadrant removal. Measurements included cumulative dissipated energy (CDE), 3 months postoperative surgically induced astigmatism (SIA), and corneal endothelial cell density (ECD) losses. Results No complications were recorded in any of the cases. Respective overall and longitudinal vs IP means were as follows: CDE, 51.6±15.6 and 55.7±15.5 vs 48.6±15.1; SIA, 0.36±0.2 D and 0.4±0.2 D vs 0.3±0.2 D; and mean ECD loss, 4.1%±10.8% and 5.9%±13.4% vs 2.7%±7.8%. The differences between longitudinal and IP were not significant for any of the three categories. Conclusion The endocapsular phacofracture debulking technique is safe and effective for phacoemulsification of hard cataracts using longitudinal or torsional IP strategies for quadrant removal with the Infiniti machine and Partial Kelman tip. PMID:26203213

Developmental Differences in Parenting Behavior: Comparing Adolescent, Emerging Adult, and Adult Mothers

ERIC Educational Resources Information Center

Lewin, Amy; Mitchell, Stephanie J.; Ronzio, Cynthia R.

2013-01-01

The nationally representative Early Childhood Longitudinal Study-Birth cohort data set was used to compare parenting behaviors of adolescent mothers (less than 19 years old), emerging adult mothers (19-25 years old), and adult mothers (greater than 25 years old) when their children were 2 years old. Regression models controlling for socioeconomic…

Comparing the Determinants of Persistence for First-Generation and Continuing-Generation Students

ERIC Educational Resources Information Center

Martin Lohfink, Mandy; Paulsen, Michael B.

2005-01-01

In this study we examined and compared the determinants of first-to-second-year persistence for 1,167 first-generation and 3,017 continuing-generation students at four-year institutions, using data from the Beginning Postsecondary Students Longitudinal Survey (Wine, et al., 2002). Because first-generation students are over represented in the most…

Succession Planning and Leadership Development for School Principals: Comparing English and South African Approaches

ERIC Educational Resources Information Center

Bush, Tony

2011-01-01

Succession planning has become increasingly important because of the shortage of headship applicants in England, and in many other countries. Leadership development is a central part of any succession planning strategy. This article compares the findings from two longitudinal studies, in England and South Africa, where the governments are seeking…

Stepping Back to Move Forward? Exploring Outdoor Education Students' Fresher and Graduate Identities and Their Impact on Employment Destinations

ERIC Educational Resources Information Center

Stott, Tim; Zaitseva, Elena; Cui, Vanessa

2014-01-01

This four-year mixed method longitudinal study utilises data collected from four cohorts of Outdoor Education (OE) students to compare "fresher" and "graduate" identities and to explore the impact of identity on graduate employment. Findings demonstrate that compared to other programmes, and the university as a whole, OE…

A Longitudinal Study of Mental Health Consumer/Survivor Initiatives: Part 2--A Quantitative Study of Impacts of Participation on New Members

ERIC Educational Resources Information Center

Nelson, Geoffrey; Ochocka, Joanna; Janzen, Rich; Trainor, John

2006-01-01

To evaluate the impacts of participation in mental health Consumer/Survivor Initiatives (CSIs), we used a nonequivalent control group design to compare new, active participants in CSIs ( n = 61) with nonactive participants ( n = 57) at baseline, 9-month, and 18-month follow-up intervals. The two groups were comparable at baseline on a wide range…

Social patterning of overeating, binge eating, compensatory behaviours and symptoms of bulimia nervosa in young adult women: results from the Australian Longitudinal Study on Women's Health.

PubMed

Koupil, Ilona; Tooth, Leigh; Heshmati, Amy; Mishra, Gita

2016-12-01

To study social patterning of overeating and symptoms of disordered eating in a general population. A representative, population-based cohort study. The Australian Longitudinal Study on Women's Health (ALSWH), Survey 1 in 1996 and Survey 2 in 2000. Women (n 12 599) aged 18-23 years completed a questionnaire survey at baseline, of whom 6866 could be studied prospectively. Seventeen per cent of women reported episodes of overeating, 16 % reported binge eating and 10 % reported compensatory behaviours. Almost 4 % of women reported symptoms consistent with bulimia nervosa. Low education, not living with family, perceived financial difficulty (OR=1·8 and 1·3 for women with severe and some financial difficulty, respectively, compared with none) and European language other than English spoken at home (OR=1·5 for European compared with Australian/English) were associated with higher prevalence of binge eating. Furthermore, longitudinal analyses indicated increased risk of persistent binge eating among women with a history of being overweight in childhood, those residing in metropolitan Australia, women with higher BMI, smokers and binge drinkers. Overeating, binge eating and symptoms of bulimia nervosa are common among young Australian women and cluster with binge drinking. Perceived financial stress appears to increase the risk of binge eating and bulimia nervosa. It is unclear whether women of European origin and those with a history of childhood overweight carry higher risk of binge eating because of genetic or cultural reasons.

Longitudinal associations between parenting style and adolescent disordered eating behaviors.

PubMed

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

2015-06-01

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

The longitudinal impact of depression on disability in Parkinson disease.

PubMed

Pontone, Gregory M; Bakker, Catherine C; Chen, Shaojie; Mari, Zoltan; Marsh, Laura; Rabins, Peter V; Williams, James R; Bassett, Susan S

2016-05-01

Depression in Parkinson disease (PD) is a common problem that worsens quality of life and causes disability. However, little is known about the longitudinal impact of depression on disability in PD. This study examined the association between disability and DSM-IV-TR depression status across six years. Longitudinal cohort study with assessments at study entry, year two, four, and six conducted in the Morris K. Udall Parkinson Disease Research Center. Recruitment totaled 137 adult men and women with idiopathic PD in which up to six years of data on demographic, motor, and non-motor variables was collected. Movement disorder specialists used the structured interview for DSM-IV-TR depressive disorders and the Northwestern Disability Scale to assess depression and disability. A generalized linear mixed model was fitted with Northwestern Disability Scale score as the dependent variable to determine the effect of baseline depression status on disability. A total of 43 participants were depressed at baseline compared to 94 without depression. Depressed participants were more likely to be female, were less educated, were less likely to take dopamine agonists, and more likely to have motor fluctuations. Controlling for these variables, symptomatic depression predicted greater disability compared to both never depressed (p = 0.0133) and remitted depression (p = 0.0009). Disability associated with symptomatic depression at baseline was greater over the entire six-year period compared to participants with remitted depressive episodes or who were never depressed. Persisting depression is associated with a long-term adverse impact on daily functioning in PD. Adequate treatment or spontaneous remission of depression improves ADL function. Copyright © 2015 John Wiley & Sons, Ltd.

An early and late peak in microglial activation in Alzheimer's disease trajectory.

PubMed

Fan, Zhen; Brooks, David J; Okello, Aren; Edison, Paul

2017-03-01

Amyloid-β deposition, neuroinflammation and tau tangle formation all play a significant role in Alzheimer's disease. We hypothesized that there is microglial activation early on in Alzheimer's disease trajectory, where in the initial phase, microglia may be trying to repair the damage, while later on in the disease these microglia could be ineffective and produce proinflammatory cytokines leading to progressive neuronal damage. In this longitudinal study, we have evaluated the temporal profile of microglial activation and its relationship between fibrillar amyloid load at baseline and follow-up in subjects with mild cognitive impairment, and this was compared with subjects with Alzheimer's disease. Thirty subjects (eight mild cognitive impairment, eight Alzheimer's disease and 14 controls) aged between 54 and 77 years underwent 11C-(R)PK11195, 11C-PIB positron emission tomography and magnetic resonance imaging scans. Patients were followed-up after 14 ± 4 months. Region of interest and Statistical Parametric Mapping analysis were used to determine longitudinal alterations. Single subject analysis was performed to evaluate the individualized pathological changes over time. Correlations between levels of microglial activation and amyloid deposition at a voxel level were assessed using Biological Parametric Mapping. We demonstrated that both baseline and follow-up microglial activation in the mild cognitive impairment cohort compared to controls were increased by 41% and 21%, respectively. There was a longitudinal reduction of 18% in microglial activation in mild cognitive impairment cohort over 14 months, which was associated with a mild elevation in fibrillar amyloid load. Cortical clusters of microglial activation and amyloid deposition spatially overlapped in the subjects with mild cognitive impairment. Baseline microglial activation was increased by 36% in Alzheimer's disease subjects compared with controls. Longitudinally, Alzheimer's disease subjects showed an increase in microglial activation. In conclusion, this is one of the first longitudinal positron emission tomography studies evaluating longitudinal changes in microglial activation in mild cognitive impairment and Alzheimer's disease subjects. We found there is an initial longitudinal reduction in microglial activation in subjects with mild cognitive impairment, while subjects with Alzheimer's disease showed an increase in microglial activation. This could reflect that activated microglia in mild cognitive impairment initially may adopt a protective activation phenotype, which later change to a cidal pro-inflammatory phenotype as disease progresses and amyloid clearance fails. Thus, we speculate that there might be two peaks of microglial activation in the Alzheimer's disease trajectory; an early protective peak and a later pro-inflammatory peak. If so, anti-microglial agents targeting the pro-inflammatory phenotype would be most beneficial in the later stages of the disease. © The Author (2017). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Composition and Longitudinal Patterns of Aquatic Insect Emergence in Small Rivers of Palawan Island, the Philippines

NASA Astrophysics Data System (ADS)

Freitag, Hendrik

2004-09-01

This study presents the first emergence trap samples from streams in the Philippines and Greater Sunda. Aquatic insect emergence from two small rivers and longitudinal patterns including estuaries are compared. A decline of total emergence towards estuaries was observed, affecting all major orders. Diptera, namely Chironomidae, dominated all sites. High abundances in Ceratopogonidae, Odonata, and Coleoptera were found, compared to other emergence studies from tropical and temperate latitudes. Ephemeroptera displayed a highly variable contribution to the emergence from Palawan as well as in other comparative studies either supported by the appropriate conditions for certain functional groups or limited by environmental variables such as pH. Trichoptera are likely to tolerate a wider range of environmental conditions and they are consequently able to fill further niches where Ephemeroptera are under-represented. Except for scarce abundances of Plecoptera observed in this and other studies from the tropics, no substantial differences in emergence composition at order level existed between temperate and tropical rivers, however, with a remarkable local variation. Components of riparian and non-aquatic insects and non-emergent fauna contributing to the collections are discussed based on trap features. (

Experimental demonstration of electron longitudinal-phase-space linearization by shaping the photoinjector laser pulse.

PubMed

Penco, G; Danailov, M; Demidovich, A; Allaria, E; De Ninno, G; Di Mitri, S; Fawley, W M; Ferrari, E; Giannessi, L; Trovó, M

2014-01-31

Control of the electron-beam longitudinal-phase-space distribution is of crucial importance in a number of accelerator applications, such as linac-driven free-electron lasers, colliders and energy recovery linacs. Some longitudinal-phase-space features produced by nonlinear electron beam self- fields, such as a quadratic energy chirp introduced by geometric longitudinal wakefields in radio-frequency (rf) accelerator structures, cannot be compensated by ordinary tuning of the linac rf phases nor corrected by a single high harmonic accelerating cavity. In this Letter we report an experimental demonstration of the removal of the quadratic energy chirp by properly shaping the electron beam current at the photoinjector. Specifically, a longitudinal ramp in the current distribution at the cathode linearizes the longitudinal wakefields in the downstream linac, resulting in a flat electron current and energy distribution. We present longitudinal-phase-space measurements in this novel configuration compared to those typically obtained without longitudinal current shaping at the FERMI linac.

Political Ideology, Confidence in Science, and Participation in Alzheimer Disease Research Studies.

PubMed

Gabel, Matthew; Gooblar, Jonathan; Roe, Catherine M; Selsor, Natalie J; Morris, John C

2018-01-18

Americans' confidence in science varies based on their political ideology. This ideological divide has potentially important effects on citizens' engagement with and participation in clinical studies of Alzheimer disease (AD). A probability sample of 1583 Americans was surveyed about their willingness to participate in longitudinal AD research and about their political attitudes. These survey results were compared with a survey of 382 participants in a longitudinal AD study at the Knight Alzheimer Disease Research Center. Among Americans, more conservative ideology decreases willingness to participate in a hypothetical longitudinal cohort study of AD both directly and through its negative effect on confidence in science. The Knight Alzheimer Disease Research Center study participants expressed more liberal ideology and greater confidence in science than Americans in general. Of the survey respondents opposed to participation, over a quarter changed to neutral or positive if the study returned their research results to them. Clinical studies of AD are likely biased toward participants who are more liberal and have higher confidence in science than the general population. This recruitment bias may be reduced by lowering the trust demanded of participants through measures such as returning research results to participants.

76 FR 22107 - Submission for OMB Review; Comment Request; NIH Toolbox for Assessment of Neurological and...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-20

... functioning (cognitive, emotional, motor and sensory) for use in large longitudinal or epidemiological studies... of 12,900 for the purpose of establishing comparative norms. The targeted population will be non...

Giftedness and Subjective Well-Being: A Study with Adults

ERIC Educational Resources Information Center

Wirthwein, Linda; Rost, Detlef H.

2011-01-01

Studies on the well-being of gifted adults are rare, and the available studies are often limited by methodological shortcomings. In a longitudinal project 101 intellectually gifted adults (mean IQ = 136) were compared to 91 adults of average intelligence (mean IQ = 103). Subjective well-being was operationalized by positive and negative…

The Academic Experience of Male High School Students with ADHD

ERIC Educational Resources Information Center

Kent, Kristine M.; Pelham, William E.; Molina, Brooke S. G.; Sibley, Margaret H.; Waschbusch, Daniel A.; Yu, Jihnhee; Gnagy, Elizabeth M.; Biswas, Aparajita; Babinski, Dara E.; Karch, Kathryn M.

2011-01-01

This study compared the high school academic experience of adolescents with and without childhood ADHD using data from the Pittsburgh ADHD Longitudinal Study (PALS). Participants were 326 males with childhood ADHD and 213 demographically similar males without ADHD who were recruited at the start of the follow-up study. Data were collected yearly…

Brief Report: A Longitudinal Study of Excessive Smiling and Laughing in Children with Angelman Syndrome

ERIC Educational Resources Information Center

Adams, Dawn; Horsler, Kate; Mount, Rebecca; Oliver, Chris

2015-01-01

Elevated laughing and smiling is a key characteristic of the Angelman syndrome behavioral phenotype, with cross-sectional studies reporting changes with environment and age. This study compares levels of laughing and smiling in 12 participants across three experimental conditions [full social interaction (with eye contact), social interaction with…

Clarifying the Link between Parental Psychological Control and Adolescents' Depressive Symptoms: Reciprocal versus Unidirectional Models

ERIC Educational Resources Information Center

Soenens, Bart; Luyckx, Koen; Vansteenkiste, Maarten; Duriez, Bart; Goossens, Luc

2008-01-01

Research has demonstrated consistent positive associations between perceived parental psychological control and adolescents' depressive symptoms, but the direction of influence remains unclear. Using a cross-lagged longitudinal design in two samples of late (Study 1, N = 396) and middle (Study 2, N = 724) adolescents, this study compared three…

Antenatal and postnatal psychopathology among women with current and past eating disorders: longitudinal patterns.

PubMed

Easter, Abigail; Solmi, Francessca; Bye, Amanda; Taborelli, Emma; Corfield, Freya; Schmidt, Ulrike; Treasure, Janet; Micali, Nadia

2015-01-01

This study aims to investigate longitudinal patterns of psychopathology during the antenatal and postnatal periods among women with current (C-ED) and past (P-ED) eating disorders. Women were recruited to a prospective longitudinal study: C-ED (n = 31), P-ED (n = 29) and healthy control (HC; n = 57). Anxiety, depression and ED symptoms were measured at four time points: first/second trimester, third trimester, 8 weeks and 6 months postpartum. Linear mixed effects models were used to test for group differences. Women with C-ED and P-ED, in all diagnostic categories, had significantly higher levels of psychopathology at all time points. ED symptoms decreased in the C-ED group, compared with an overall increase in the other two groups but subsequently increased after pregnancy. Overall, depression and state and trait anxiety scores decreased in the C-ED group compared with the HC group throughout the antenatal and postnatal periods. High levels of psychopathology are common throughout the antenatal and postnatal periods among women with current and past ED, and despite some overall reductions, symptoms remain clinically significant. © 2014 The Authors. European Eating Disorders Review published by John Wiley & Sons, Ltd. © 2014 The Authors. European Eating Disorders Review published by John Wiley & Sons, Ltd.

Enhancing the stabilization of aircraft pitch motion control via intelligent and classical method

NASA Astrophysics Data System (ADS)

Lukman, H.; Munawwarah, S.; Azizan, A.; Yakub, F.; Zaki, S. A.; Rasid, Z. A.

2017-12-01

The pitching movement of an aircraft is very important to ensure passengers are intrinsically safe and the aircraft achieve its maximum stability. The equations governing the motion of an aircraft are a complex set of six nonlinear coupled differential equations. Under certain assumptions, it can be decoupled and linearized into longitudinal and lateral equations. Pitch control is a longitudinal problem and thus, only the longitudinal dynamics equations are involved in this system. It is a third order nonlinear system, which is linearized about the operating point. The system is also inherently unstable due to the presence of a free integrator. Because of this, a feedback controller is added in order to solve this problem and enhance the system performance. This study uses two approaches in designing controller: a conventional controller and an intelligent controller. The pitch control scheme consists of proportional, integral and derivatives (PID) for conventional controller and fuzzy logic control (FLC) for intelligent controller. Throughout the paper, the performance of the presented controllers are investigated and compared based on the common criteria of step response. Simulation results have been obtained and analysed by using Matlab and Simulink software. The study shows that FLC controller has higher ability to control and stabilize the aircraft's pitch angle as compared to PID controller.

Sports participation and parent-reported health-related quality of life in children: longitudinal associations.

PubMed

Vella, Stewart A; Cliff, Dylan P; Magee, Christopher A; Okely, Anthony D

2014-06-01

To investigate the longitudinal association between sports participation and parent-reported health-related quality of life (HRQOL) in children. Cohort study that used data drawn from the Longitudinal Study of Australian Children in waves 3 (2008) and 4 (2010). Participants were a nationally representative sample of 4042 Australian children ages 8.25 (SD = 0.44) years at baseline and followed-up 24 months later. After we adjusted for multiple covariates, children who continued to participate in sports between the ages of 8 and 10 years had greater parent-reported HRQOL at age 10 (Eta2 = .02) compared with children who did not participate in sports (P ≤ .001), children who commenced participation after 8 years of age (P = .004), and children who dropped out of sports before reaching 10 years of age (P = .04). Children who participated in both team and individual sports (P = .02) or team sports alone (P = .04) had greater HRQOL compared with children who participated in individual sports alone (Eta2 = .01). The benefits of sports participation were strongest for girls (P < .05; Eta2 = .003). Children's participation in developmentally appropriate team sports helps to protect HRQOL and should be encouraged at an early age and maintained for as long as possible. Copyright © 2014 Elsevier Inc. All rights reserved.

Using facebook to maximize follow-up response rates in a longitudinal study of adults who use methamphetamine.

PubMed

Bolanos, Franklin; Herbeck, Diane; Christou, Dayna; Lovinger, Katherine; Pham, Aurora; Raihan, Adnan; Rodriguez, Luz; Sheaff, Patricia; Brecht, Mary-Lynn

2012-01-01

This study examines the process and effects of using facebook (FB) to locate and re-contact study participants targeted for follow up in a longitudinal study of adult methamphetamine users (N = 649). A follow-up interview was conducted in 2009-11 approximately 8 years after previous study participation. Our paper describes re-contact efforts involving FB, including IRB regulatory issues and the effectiveness of using FB compared to mailings and phone calls. A total of 48 of the 551 surviving non-incarcerated participants who agreed to be contacted for follow up studies were contacted via FB, of whom 11 completed the follow-up interview. Those contacted through FB were more likely to be younger, female, relocated out-of-state, and reported somewhat higher rates of anxiety and cognitive problems compared to those not located on FB. Although participants contacted through FB are likely to differ demographically from those contacted by phone or mail, FB provides a potentially effective means to expand conventional methods of correspondence for contacting hard to reach participants.

Using Facebook to Maximize Follow-Up Response Rates in a Longitudinal Study of Adults Who Use Methamphetamine

PubMed Central

Bolanos, Franklin; Herbeck, Diane; Christou, Dayna; Lovinger, Katherine; Pham, Aurora; Raihan, Adnan; Rodriguez, Luz; Sheaff, Patricia; Brecht, Mary-Lynn

2012-01-01

This study examines the process and effects of using facebook (FB) to locate and re-contact study participants targeted for follow up in a longitudinal study of adult methamphetamine users (N = 649). A follow-up interview was conducted in 2009–11 approximately 8 years after previous study participation. Our paper describes re-contact efforts involving FB, including IRB regulatory issues and the effectiveness of using FB compared to mailings and phone calls. A total of 48 of the 551 surviving non-incarcerated participants who agreed to be contacted for follow up studies were contacted via FB, of whom 11 completed the follow-up interview. Those contacted through FB were more likely to be younger, female, relocated out-of-state, and reported somewhat higher rates of anxiety and cognitive problems compared to those not located on FB. Although participants contacted through FB are likely to differ demographically from those contacted by phone or mail, FB provides a potentially effective means to expand conventional methods of correspondence for contacting hard to reach participants. PMID:22879750

Child incarceration and long-term adult health outcomes: a longitudinal study.

PubMed

Barnert, Elizabeth S; Abrams, Laura S; Tesema, Lello; Dudovitz, Rebecca; Nelson, Bergen B; Coker, Tumaini; Bath, Eraka; Biely, Christopher; Li, Ning; Chung, Paul J

2018-03-12

Purpose Although incarceration may have life-long negative health effects, little is known about associations between child incarceration and subsequent adult health outcomes. The paper aims to discuss this issue. Design/methodology/approach The authors analyzed data from 14,689 adult participants in the National Longitudinal Study of Adolescent to Adult Health (Add Health) to compare adult health outcomes among those first incarcerated between 7 and 13 years of age (child incarceration); first incarcerated at>or=14 years of age; and never incarcerated. Findings Compared to the other two groups, those with a history of child incarceration were disproportionately black or Hispanic, male, and from lower socio-economic strata. Additionally, individuals incarcerated as children had worse adult health outcomes, including general health, functional limitations (climbing stairs), depressive symptoms, and suicidality, than those first incarcerated at older ages or never incarcerated. Research limitations/implications Despite the limitations of the secondary database analysis, these findings suggest that incarcerated children are an especially medically vulnerable population. Practical implications Programs and policies that address these medically vulnerable children's health needs through comprehensive health and social services in place of, during, and/or after incarceration are needed. Social implications Meeting these unmet health and social service needs offers an important opportunity to achieve necessary health care and justice reform for children. Originality/value No prior studies have examined the longitudinal relationship between child incarceration and adult health outcomes.

Young adult gay and bisexual men's stigma experiences and mental health: An 8-year longitudinal study.

PubMed

Pachankis, John E; Sullivan, Timothy J; Feinstein, Brian A; Newcomb, Michael E

2018-04-05

This study investigated longitudinal trajectories of stigma (i.e., enacted, anticipated, internalized, concealed); stress-sensitive mental health disorder symptoms (i.e., depression, social anxiety); and their associations across 8 annual assessments in a sample of 128 young gay and bisexual U.S. university students. All forms of stigma significantly decreased over time, while depressive symptoms remained stable and social anxiety symptoms significantly increased. Men from higher socioeconomic backgrounds experienced quicker reductions in anticipated stigma, compared to men from lower socioeconomic backgrounds. More self-described feminine men experienced quicker reductions in concealment, compared to more self-described masculine men. Enacted stigma demonstrated contemporaneous associations with depression and social anxiety across 8 years; and anticipated stigma and internalized stigma demonstrated contemporaneous associations with social anxiety across 8 years. Enacted stigma was more strongly associated with depressive symptoms among men who reported greater masculinity compared to those who reported greater femininity. Findings are discussed in terms of common developmental influences across early sexual orientation identity formation, including gay and bisexual young men's resilience to stigma-based stress; the transition from college; and the rapidly changing social climate surrounding sexual minority individuals. Findings suggest the need for future longitudinal examinations of stigma and mental health among sexual minorities that utilize multiple age cohorts to determine the relative contribution of cohort-specific versus common maturational factors influencing the mental health of this population. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Longitudinal Study of the Six Degrees of Freedom Cervical Spine Range of Motion During Dynamic Flexion, Extension, and Rotation After Single-level Anterior Arthrodesis.

PubMed

Anderst, William J; West, Tyler; Donaldson, William F; Lee, Joon Y; Kang, James D

2016-11-15

A longitudinal study using biplane radiography to measure in vivo intervertebral range of motion (ROM) during dynamic flexion/extension, and rotation. To longitudinally compare intervertebral maximal ROM and midrange motion in asymptomatic control subjects and single-level arthrodesis patients. In vitro studies consistently report that adjacent segment maximal ROM increases superior and inferior to cervical arthrodesis. Previous in vivo results have been conflicting, indicating that maximal ROM may or may not increase superior and/or inferior to the arthrodesis. There are no previous reports of midrange motion in arthrodesis patients and similar-aged controls. Eight single-level (C5/C6) anterior arthrodesis patients (tested 7 ± 1 months and 28 ± 6 months postsurgery) and six asymptomatic control subjects (tested twice, 58 ± 6 months apart) performed dynamic full ROM flexion/extension and axial rotation whereas biplane radiographs were collected at 30 images per second. A previously validated tracking process determined three-dimensional vertebral position from each pair of radiographs with submillimeter accuracy. The intervertebral maximal ROM and midrange motion in flexion/extension, rotation, lateral bending, and anterior-posterior translation were compared between test dates and between groups. Adjacent segment maximal ROM did not increase over time during flexion/extension, or rotation movements. Adjacent segment maximal rotational ROM was not significantly greater in arthrodesis patients than in corresponding motion segments of similar-aged controls. C4/C5 adjacent segment rotation during the midrange of head motion and maximal anterior-posterior translation were significantly greater in arthrodesis patients than in the corresponding motion segment in controls on the second test date. C5/C6 arthrodesis appears to significantly affect midrange, but not end-range, adjacent segment motions. The effects of arthrodesis on adjacent segment motion may be best evaluated by longitudinal studies that compare maximal and midrange adjacent segment motion to corresponding motion segments of similar-aged controls to determine if the adjacent segment motion is truly excessive. 3.

Comparative optimism in older adults' future health expectations.

PubMed

Vanderzanden, Karen; Ruthig, Joelle C

2018-05-13

Despite a common belief that health declines with age, many older adults remain optimistic about their future health. However, the longitudinal impact of personal and comparatively optimistic future health estimates (FHEs) is unclear. Among 408 older adults (M age  = 70.32 years), this study identified the prevalence, source, and two-year stability of comparatively optimistic FHEs; examined demographic, psychosocial, and health correlates of comparative FHEs; and assessed the role of comparative FHEs in predicting eight-year survival odds. Nearly half of participants were comparatively optimistic due to interpersonal pessimism more so than personal optimism. Regarding stability, comparative optimism declined over the two-year period. Being younger and having more perceived control, dispositional optimism, and recent positive emotions were associated with better FHEs for oneself and a similar other. Beyond effects of age, gender, relationship status, and dispositional optimism, optimistic personal FHEs predicted eight-year survival odds. Findings have implications for predicting survival and advancing the conceptual understanding of comparative FHEs. Statement of contribution What is already known on the subject? Previous research has demonstrated that older adults tend to believe diminished health accompanies increasing age. Despite this notion, older adults remain comparatively optimistic about their health. What does this study add? The longitudinal results of the current study indicated that nearly half of participants were categorized as comparative optimists, primarily due to interpersonal pessimism. The current study demonstrated that there is little distinction between personal FHEs and those for a similar other in terms of demographic, psychosocial, and health correlates. The current study identified factors that predicted eight-year survival among older adults, such as being female, younger, in a committed relationship, and better personal FHEs. © 2018 The British Psychological Society.

Dorsal longitudinal foreskin cut is associated with reduced risk of HIV, syphilis and genital herpes in men: a cross-sectional study in Papua New Guinea

PubMed Central

Vallely, Andrew J; MacLaren, David; David, Matthew; Toliman, Pamela; Kelly-Hanku, Angela; Toto, Ben; Tommbe, Rachael; Kombati, Zure; Kaima, Petronia; Browne, Kelwyn; Manineng, Clement; Simeon, Lalen; Ryan, Claire; Wand, Handan; Hill, Peter; Law, Greg; Siba, Peter M; McBride, W John H; Kaldor, John M

2017-01-01

Abstract Introduction: Various forms of penile foreskin cutting are practised in Papua New Guinea. In the context of an ecological association observed between HIV infection and the dorsal longitudinal foreskin cut, we undertook an investigation of this relationship at the individual level. Methods: We conducted a cross-sectional study among men attending voluntary confidential HIV counselling and testing clinics. Following informed consent, participants had a face-to-face interview and an examination to categorize foreskin status. HIV testing was conducted on site and relevant specimens collected for laboratory-based Herpes simplex type-2 (HSV-2), syphilis, Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), and Trichomonas vaginalis (TV) testing. Results: Overall, 1073 men were enrolled: 646 (60.2%) were uncut; 339 (31.6%) had a full dorsal longitudinal cut; 72 (6.7%) a partial dorsal longitudinal cut; and 14 (1.3%) were circumcised. Overall, the prevalence of HIV was 12.3%; HSV-2, 33.6%; active syphilis, 12.1%; CT, 13.4%; NG, 14.1%; and TV 7.6%. Compared with uncut men, men with a full dorsal longitudinal cut were significantly less likely to have HIV (adjusted odds ratio [adjOR] 0.25, 95%CI: 0.12, 0.51); HSV-2 (adjOR 0.60, 95%CI: 0.41, 0.87); or active syphilis (adjOR 0.55, 95%CI: 0.31, 0.96). This apparent protective effect was restricted to men cut prior to sexual debut. There was no difference between cut and uncut men for CT, NG or TV. Conclusions: In this large cross-sectional study, men with a dorsal longitudinal foreskin cut were significantly less likely to have HIV, HSV-2 and syphilis compared with uncut men, despite still having a complete (albeit morphologically altered) foreskin. The protective effect of the dorsal cut suggests that the mechanism by which male circumcision works is not simply due to the removal of the inner foreskin and its more easily accessible HIV target cells. Exposure of the penile glans and inner foreskin appear to be key mechanisms by which male circumcision confers protection. Further research in this unique setting will help improve our understanding of the fundamental immunohistologic mechanisms by which male circumcision provides protection, and may lead to new biomedical prevention strategies at the mucosal level. PMID:28406272

Dorsal longitudinal foreskin cut is associated with reduced risk of HIV, syphilis and genital herpes in men: a cross-sectional study in Papua New Guinea.

PubMed

Vallely, Andrew J; MacLaren, David; David, Matthew; Toliman, Pamela; Kelly-Hanku, Angela; Toto, Ben; Tommbe, Rachael; Kombati, Zure; Kaima, Petronia; Browne, Kelwyn; Manineng, Clement; Simeon, Lalen; Ryan, Claire; Wand, Handan; Hill, Peter; Law, Greg; Siba, Peter M; McBride, W John H; Kaldor, John M

2017-04-03

Various forms of penile foreskin cutting are practised in Papua New Guinea. In the context of an ecological association observed between HIV infection and the dorsal longitudinal foreskin cut, we undertook an investigation of this relationship at the individual level. We conducted a cross-sectional study among men attending voluntary confidential HIV counselling and testing clinics. Following informed consent, participants had a face-to-face interview and an examination to categorize foreskin status. HIV testing was conducted on site and relevant specimens collected for laboratory-based Herpes simplex type-2 (HSV-2), syphilis, Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), and Trichomonas vaginalis (TV) testing. Overall, 1073 men were enrolled: 646 (60.2%) were uncut; 339 (31.6%) had a full dorsal longitudinal cut; 72 (6.7%) a partial dorsal longitudinal cut; and 14 (1.3%) were circumcised. Overall, the prevalence of HIV was 12.3%; HSV-2, 33.6%; active syphilis, 12.1%; CT, 13.4%; NG, 14.1%; and TV 7.6%. Compared with uncut men, men with a full dorsal longitudinal cut were significantly less likely to have HIV (adjusted odds ratio [adjOR] 0.25, 95%CI: 0.12, 0.51); HSV-2 (adjOR 0.60, 95%CI: 0.41, 0.87); or active syphilis (adjOR 0.55, 95%CI: 0.31, 0.96). This apparent protective effect was restricted to men cut prior to sexual debut. There was no difference between cut and uncut men for CT, NG or TV. In this large cross-sectional study, men with a dorsal longitudinal foreskin cut were significantly less likely to have HIV, HSV-2 and syphilis compared with uncut men, despite still having a complete (albeit morphologically altered) foreskin. The protective effect of the dorsal cut suggests that the mechanism by which male circumcision works is not simply due to the removal of the inner foreskin and its more easily accessible HIV target cells. Exposure of the penile glans and inner foreskin appear to be key mechanisms by which male circumcision confers protection.Further research in this unique setting will help improve our understanding of the fundamental immunohistologic mechanisms by which male circumcision provides protection, and may lead to new biomedical prevention strategies at the mucosal level.

Progression of Amygdala Volumetric Abnormalities in Adolescents after Their First Manic Episode

ERIC Educational Resources Information Center

Bitter, Samantha M.; Mills, Neil P.; Adler, Caleb M.; Strakowski, Stephen M.; DelBello, Melissa P.

2011-01-01

Objective: Although previous neuroimaging studies suggest that adolescents with bipolar disorder exhibit smaller amygdala volumes compared with healthy adolescents, whether these abnormalities are present at illness onset or instead develop over time remains unclear. The aim of this study was to conduct a prospective longitudinal investigation…

Consequences of Retirement: An Essay.

ERIC Educational Resources Information Center

Bodily, Gerald P.

Studies on retirement reporting that, compared to people not retired, recent retirees exhibited less income, more physical and mental illness, lower self-esteem, and less life satisfaction have been challenged and new findings have been revealed by longitudinal studies using data from large samples. It appears that perhaps the way individuals…

Connecting Theory to Practice: Evaluating a Brain-Based Writing Curriculum

ERIC Educational Resources Information Center

Griffee, Dale T.

2007-01-01

This 10 week longitudinal evaluation study evaluated a brain-based learning curriculum proposed by Smilkstein (2003) by comparing student performance in a traditional basic writing curriculum with NHLP-oriented basic writing curriculum. The study included two classes each of experimental and traditional methods. Results of the data, gathered by…

Principal Turnover: Upheaval and Uncertainty in Charter Schools?

ERIC Educational Resources Information Center

Ni, Yongmei; Sun, Min; Rorrer, Andrea

2015-01-01

Purpose: Informed by literature on labor market and school choice, this study aims to examine the dynamics of principal career movements in charter schools by comparing principal turnover rates and patterns between charter schools and traditional public schools. Research Methods/Approach: This study uses longitudinal data on Utah principals and…

Unsafe at Any Age: Linking Childhood and Adolescent Maltreatment to Delinquency and Crime

ERIC Educational Resources Information Center

Mersky, Joshua P.; Topitzes, James; Reynolds, Arthur J.

2012-01-01

Objectives: This study compares the effects of childhood maltreatment and adolescent maltreatment on delinquency and crime, including violent and nonviolent offending. Methods: Data were derived from the Chicago Longitudinal Study, a prospective investigation of 1,539 underprivileged, minority subjects. Results: Results confirmed that rates of…

A Longitudinal Study of Psychological Differentiation In Nigerian Children.

ERIC Educational Resources Information Center

Jegede, R. Olukayode; Bamgboye, E. Afolabi

1983-01-01

Presents results of a three-year follow-up study of the development of psychological differentiation in Nigerian children. Human figure drawings made in 1974 and 1977 by 204 subjects aged 7 to 14 years were analyzed using Witkins Articulation of Body Concept scale and compared. (Author/RH)

Comparison of torsional and longitudinal modes using phacoemulsification parameters.

PubMed

Rekas, Marek; Montés-Micó, Robert; Krix-Jachym, Karolina; Kluś, Adam; Stankiewicz, Andrzej; Ferrer-Blasco, Teresa

2009-10-01

To compare phacoemulsification parameters of torsional and longitudinal ultrasound modes. Ophthalmology Department, Military Health Service Institute, Warsaw, Poland. This prospective study evaluated eyes 1, 7, and 30 days after phacoemulsification with an Infiniti Vision System using the torsional or longitudinal ultrasound (US) mode. Cataract classification was according to the Lens Opacities Classification System II. Nucleus fragmentation was by the phaco-chop and quick-chop methods. Primary outcome measures were phaco time, mean phaco power, mean torsional amplitude, and aspiration time. Total energy, defined as cumulative dissipated energy (CDE) x aspiration time, and the effective coefficient, defined as aspiration time/phaco time, were also calculated. Four hundred eyes were evaluated. The CDE was statistically significantly lower in the torsional mode for nucleus grades I, II, and III (P<.001) but not for grade IV (P>.05). Aspiration time was statistically significantly shorter in the torsional mode than in the longitudinal mode for nucleus grades III and IV (P<.05). Total energy was significantly lower in the torsional mode for all nucleus densities (P<.05). The effective coefficient was significantly lower in the longitudinal mode except for nucleus grade I (P<.05). Torsional phacoemulsification was more effective than longitudinal phacoemulsification in the amount of applied fluid and the quantity of US energy expended. With the torsional method, it was possible to maintain a constant ratio of amount of fluid flow to quantity of US energy used, regardless of nucleus density.

Within-individual versus between-individual predictors of antisocial behaviour: A longitudinal study of young people in Victoria, Australia

PubMed Central

Hemphill, Sheryl A; Heerde, Jessica A; Herrenkohl, Todd I; Farrington, David P

2016-01-01

In an influential 2002 paper, Farrington and colleagues argued that to understand ‘causes’ of delinquency, within-individual analyses of longitudinal data are required (compared to the vast majority of analyses that have focused on between-individual differences). The current paper aimed to complete similar analyses to those conducted by Farrington and colleagues by focusing on the developmental correlates and risk factors for antisocial behaviour and by comparing within-individual and between-individual predictors of antisocial behaviour using data from the youngest Victorian cohort of the International Youth Development Study, a state-wide representative sample of 927 students from Victoria, Australia. Data analysed in the current paper are from participants in Year 6 (age 11–12 years) in 2003 to Year 11 (age 16–17 years) in 2008 (N = 791; 85% retention) with data collected almost annually. Participants completed a self-report survey of risk and protective factors and antisocial behaviour. Complete data were available for 563 participants. The results of this study showed all but one of the forward- (family conflict) and backward-lagged (low attachment to parents) correlations were statistically significant for the within-individual analyses compared with all analyses being statistically significant for the between-individual analyses. In general, between-individual correlations were greater in magnitude than within-individual correlations. Given that forward-lagged within-individual correlations provide more salient measures of causes of delinquency, it is important that longitudinal studies with multi-wave data analyse and report their data using both between-individual and within-individual correlations to inform current prevention and early intervention programs seeking to reduce rates of antisocial behaviour. PMID:28123186

Lack of significant association between type 2 diabetes mellitus with longitudinal change in diurnal salivary cortisol: the multiethnic study of atherosclerosis

PubMed Central

Spanakis, Elias K.; Wang, Xu; Sánchez, Brisa N.; Diez Roux, Ana V.; Needham, Belinda L.; Wand, Gary S.; Seeman, Teresa; Golden, Sherita Hill

2016-01-01

Cross-sectional association has been shown between type 2 diabetes and hypothalamic–pituitary–adrenal (HPA) axis dysregulation; however, the temporality of this association is unknown. Our aim was to determine if type 2 diabetes is associated with longitudinal change in daily cortisol curve features. We hypothesized that the presence of type 2 diabetes may lead to a more blunted and abnormal HPA axis profile over time, suggestive of increased HPA axis dysregulation. This was a longitudinal cohort study, including 580 community-dwelling individuals (mean age 63.7 ± 9.1 years; 52.8 % women) with (n = 90) and without (n = 490) type 2 diabetes who attended two MultiEthnic Study of Atherosclerosis Stress ancillary study exams separated by 6 years. Outcome measures that were collected were wake-up and bedtime cortisol, cortisol awakening response (CAR), total area under the curve (AUC), and early, late, and overall decline slopes. In univariate analyses, wake-up and AUC increased over 6 years more in persons with as compared to those without type 2 diabetes (11 vs. 7 % increase for wake-up and 17 vs. 11 % for AUC). The early decline slope became flatter over time with a greater flattening observed in diabetic compared to non-diabetic individuals (23 vs. 9 % flatter); however, the change was only statistically significant for wake-up cortisol (p-value: 0.03). Over time, while CAR was reduced more, late decline and overall decline became flatter, and bedtime cortisol increased less in those with as compared to those without type 2 diabetes, none of these changes were statistically significant in adjusted models. We did not identify any statistically significant change in cortisol curve features over 6 years by type 2 diabetes status. PMID:26895003

Lower Frailty Incidence Among Mexican American than Among European American Older Adults: The San Antonio Longitudinal Study of Aging

PubMed Central

Espinoza, Sara E.; Jung, Inkyung; Hazuda, Helen

2010-01-01

OBJECTIVES to directly compare frailty incidence between Mexican American (MA) and European American (EA) older adults. DESIGN longitudinal, observational cohort study. SETTING socioeconomically diverse neighborhoods in San Antonio, TX. PARTICIPANTS 301 MAs and 305 EAs in the San Antonio Longitudinal Study of Aging (SALSA) who were non-frail at baseline. MEASUREMENTS Frailty was assessed at baseline and three follow-ups conducted over an average of 9.9 years using well-established criteria from the Cardiovascular Health Study. Covariates included baseline age, sex, socioeconomic status (SES), pre-frailty status, diabetes, and comorbidity. The adjusted ethnic odds (MA vs. EA) of incident frailty were estimated using generalized estimating equations. RESULTS There was no ethnic difference in the unadjusted incidence of frailty over the three follow-up examinations (OR=0.97, 95%CI: 0.62–1.52), even though baseline SES was significantly lower among MAs than among EAs. After covariate adjustment, the odds of incident frailty were significantly lower in MAs compared to EAs (OR=0.40, 95%CI: 0.23–0.72). Other significant predictors of frailty in the adjusted model were pre-frailty (ORpresent vs. absent = 3.19, 95%CI: 1.86–5.47), education (OR1-year increment = 0.89, 95%CI: 0.83–0.96), and income (OR1-year increment = 0.88, 95%CI: 0.79–2.04). CONCLUSION These findings lend support to the Hispanic Paradox and suggest that MAs who live to older ages compared with similarly aged EAs are less likely to become frail. Further research is needed to identify the underlying biological and social mechanisms which explain this finding in order to enhance the development of interventions for the prevention and treatment of this clinical geriatric syndrome. PMID:21054295

Sexual Behavior and Contraceptive Use Among 18 to 19 year old Adolescent Women By Weight Status: A Longitudinal Analysis

PubMed Central

Chang, Tammy; Davis, Matthew M.; Kusunoki, Yasamin; Ela, Elizabeth J.; Hall, Kelli S.; Barber, Jennifer S.

2015-01-01

Objective To describe the association between weight status and sexual practices among 18-19 year-old women. Study design We analyzed a population-based longitudinal study of 18-19 year-old women residing in a Michigan county at cohort inception. Weekly journal surveys measured sexual practices, including contraceptive behaviors. Outcomes included proportion of weeks with a partner, proportion of weeks with sexual intercourse, number of partners, average length of relationships, proportion of weeks with contraception use, and proportion of weeks where contraception was used consistently. We examined 26,545 journal surveys from 900 women over the first study year. Ordinary least squares regression models for each outcome examined differences by weight status, controlling for sociodemographic characteristics. Results The mean proportion of weeks in which adolescents reported sexual intercourse was 52%; there was no difference by weight status. Among weeks in which adolescents reported sexual activity, obese adolescents had a lower proportion of weeks where any contraception was used compared with normal-weight adolescents (84% vs 91%, p=0.011). Among weeks in which adolescents reported sexual activity and contraceptive use, obese adolescents had a lower proportion of weeks with consistent contraceptive use (68% vs 78%, p=0.016) and oral contraceptive pill use (27% vs 45%, p=0.001) compared with normal-weight adolescents. All other relationships by weight status were not statistically significant. Conclusions In this longitudinal study, obese adolescent women were less likely to use contraception, and less likely to use it consistently when compared with normal-weight peers. Findings suggest obesity may be an important factor associated with adolescent women’s sexual behavior. PMID:26143383

Longitudinal Changes of Resting-State Functional Connectivity during Motor Recovery after Stroke

PubMed Central

Park, Chang-hyun; Chang, Won Hyuk; Ohn, Suk Hoon; Kim, Sung Tae; Bang, Oh Young; Pascual-Leone, Alvaro; Kim, Yun-Hee

2013-01-01

Background and Purpose Functional magnetic resonance imaging (fMRI) studies could provide crucial information on the neural mechanisms of motor recovery in stroke patients. Resting-state fMRI is applicable to stroke patients who are not capable of proper performance of the motor task. In this study, we explored neural correlates of motor recovery in stroke patients by investigating longitudinal changes in resting-state functional connectivity of the ipsilesional primary motor cortex (M1). Methods A longitudinal observational study using repeated fMRI experiments was conducted in 12 patients with stroke. Resting-state fMRI data were acquired four times over a period of 6 months. Patients participated in the first session of fMRI shortly after onset, and thereafter in subsequent sessions at 1, 3, and 6 months after onset. Resting-state functional connectivity of the ipsilesional M1 was assessed and compared with that of healthy subjects. Results Compared with healthy subjects, patients demonstrated higher functional connectivity with the ipsilesional frontal and parietal cortices, bilateral thalamus, and cerebellum. Instead, functional connectivity with the contralesional M1 and occipital cortex were decreased in stroke patients. Functional connectivity between the ipsilesional and contralesional M1 showed the most asymmetry at 1 month after onset to the ipsilesional side. Functional connectivity of the ipsilesional M1 with the contralesional thalamus, supplementary motor area, and middle frontal gyrus at onset was positively correlated with motor recovery at 6 months after stroke. Conclusions Resting-state fMRI elicited distinctive but comparable results with previous task-based fMRI, presenting complementary and practical values for use in the study of stroke patients. PMID:21441147

Gendered Fields: Sports and Advanced Course Taking in High School

PubMed Central

Pearson, Jennifer; Crissey, Sarah R.; Riegle-Crumb, Catherine

2010-01-01

This study explores the association between sports participation and course taking in high school, specifically comparing subjects with varied gendered legacies—science and foreign language. Analyses of a nationally representative longitudinal sample (N=5,447) of U.S. adolescents from the National Longitudinal Study of Adolescent Health and the linked Adolescent Health and Academic Achievement transcript study show that male and female athletes are more likely than non-athletes to take both advanced foreign language and Physics, largely because of their higher academic orientation. However, the association between sports participation and course taking was strongest for girls’ Physics coursework, suggesting that sports may provide girls with a unique opportunity to develop the skills and confidence to persevere in the masculine domain of science. PMID:20221304

An Inverse U-Shaped Curve of Resting-State Networks in Individuals at High Risk of Alzheimer's Disease.

PubMed

Ye, Qing; Chen, Haifeng; Su, Fan; Shu, Hao; Gong, Liang; Xie, Chunming; Zhou, Hong; Bai, Feng

Higher functional connectivity (FC) in resting-state networks has been shown in individuals at risk of Alzheimer's disease (AD) by many studies. However, the longitudinal trajectories of the FC remain unknown. The present 35-month follow-up study aimed to explore longitudinal changes in higher FC in multiple resting-state networks in subjects with the apolipoprotein E ε4 allele (ApoE4) and/or amnestic mild cognitive impairment (aMCI). Fifty-one subjects with aMCI and 64 cognitively normal (CN) subjects underwent neuropsychological tests and resting-state functional magnetic resonance imaging (fMRI) scans twice from April 2011 to June 2015. Subjects were divided into 4 groups according to diagnosis and ApoE4 status. The CN non-ApoE4 group served as a control group, and other groups served as AD risk groups. The cross-sectional and longitudinal patterns of multiple resting-state networks, including default mode network, hippocampus network, executive control network, and salience network, were explored by comparing FC data between groups and between time points, respectively. At baseline, compared with the control group, the AD risk groups showed higher FC with 8 regions in multiple networks. At follow-up, 6 of the regions displayed longitudinally decreased FC in AD risk groups. In contrast, the FC with all of these regions was maintained in the control group. Notably, among the 3 risk groups, most of the higher FC at baseline (5 of the 8 regions) and longitudinally decreased FC at follow-up (4 of the 6 regions) were shown in the aMCI ApoE4 group. Higher resting-state FC is followed by a decline in subjects at AD risk, and this inverse U-shaped trajectory is more notable in subjects with higher risk. © Copyright 2018 Physicians Postgraduate Press, Inc.

Substantia Nigra Free Water Increases Longitudinally in Parkinson Disease.

PubMed

Guttuso, T; Bergsland, N; Hagemeier, J; Lichter, D G; Pasternak, O; Zivadinov, R

2018-02-01

Free water in the posterior substantia nigra obtained from a bi-tensor diffusion MR imaging model has been shown to significantly increase over 1- and 4-year periods in patients with early-stage idiopathic Parkinson disease compared with healthy controls, which suggests that posterior substantia nigra free water may be an idiopathic Parkinson disease progression biomarker. Due to the known temporal posterior-to-anterior substantia nigra degeneration in idiopathic Parkinson disease, we assessed longitudinal changes in free water in both the posterior and anterior substantia nigra in patients with later-stage idiopathic Parkinson disease and age-matched healthy controls for comparison. Nineteen subjects with idiopathic Parkinson disease and 19 age-matched healthy control subjects were assessed on the same 3T MR imaging scanner at baseline and after approximately 3 years. Baseline mean idiopathic Parkinson disease duration was 7.1 years. Both anterior and posterior substantia nigra free water showed significant intergroup differences at baseline ( P < .001 and P = .014, respectively, idiopathic Parkinson disease versus healthy controls); however, only anterior substantia nigra free water showed significant longitudinal group × time interaction increases ( P = .021, idiopathic Parkinson disease versus healthy controls). There were no significant longitudinal group × time interaction differences found for conventional diffusion tensor imaging or free water-corrected DTI assessments in either the anterior or posterior substantia nigra. Results from this study provide further evidence supporting substantia nigra free water as a promising disease-progression biomarker in idiopathic Parkinson disease that may help to identify disease-modifying therapies if used in future clinical trials. Our novel finding of longitudinal increases in anterior but not posterior substantia nigra free water is potentially a result of the much longer disease duration of our cohort compared with previously studied cohorts and the known posterior-to-anterior substantia nigra degeneration that occurs over time in idiopathic Parkinson disease. © 2018 by American Journal of Neuroradiology.

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

PubMed

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

2017-08-01

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

Pathological Correlates of Cognitive Impairment in The University of Manchester Longitudinal Study of Cognition in Normal Healthy Old Age.

PubMed

Robinson, Andrew C; Davidson, Yvonne S; Horan, Michael A; Pendleton, Neil; Mann, David M A

2018-01-01

The neuropathological changes responsible for cognitive impairment and dementia remain incompletely understood. Longitudinal studies with a brain donation end point allow the opportunity to examine relationships between cognitive status and neuropathology. We report on the first 97 participants coming to autopsy with sufficient clinical information from The University of Manchester Longitudinal Study of Cognition in Normal Healthy Old Age. This study began in 1983 and recruited 6,542 healthy individuals between 1983 and 1994, 312 of whom consented to brain donation. Alzheimer-type pathology was common throughout the cohort and generally correlated well with cognitive status. However, there was some overlap between cognitive status and measures of Alzheimer pathology with 26% of cognitively intact participants reaching either CERAD B or C, 11% reaching Thal phase 4 or 5, and 29% reaching Braak stage III- VI. Cerebral amyloid angiopathy(CAA), α-synuclein, and TDP-43 pathology was less common, but when present correlated well with cognitive status. Possession of APOEɛ4 allele(s) was associated with more severe Alzheimer-type and CAA pathology and earlier death, whereas possession of APOEɛ2 allele(s) had no effect on pathology but was more common in cognitively intact individuals. The University of Manchester Longitudinal Study of Cognition in Normal Healthy Old Age cohort is pathologically representative when compared with similar studies. Cognitive impairment in life correlates strongly with all pathologies examined and the APOE status of an individual can affect pathology severity and longevity.

Feasibility study of a procedure to detect and warn of low level wind shear

NASA Technical Reports Server (NTRS)

Turkel, B. S.; Kessel, P. A.; Frost, W.

1981-01-01

A Doppler radar system which provides an aircraft with advanced warning of longitudinal wind shear is described. This system uses a Doppler radar beamed along the glide slope linked with an on line microprocessor containing a two dimensional, three degree of freedom model of the motion of an aircraft including pilot/autopilot control. The Doppler measured longitudinal glide slope winds are entered into the aircraft motion model, and a simulated controlled aircraft trajectory is calculated. Several flight path deterioration parameters are calculated from the computed aircraft trajectory information. The aircraft trajectory program, pilot control models, and the flight path deterioration parameters are discussed. The performance of the computer model and a test pilot in a flight simulator through longitudinal and vertical wind fields characteristic of a thunderstorm wind field are compared.

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

NASA Technical Reports Server (NTRS)

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

2004-01-01

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

Changes in Approaches to Learning over Three Years of University Undergraduate Study

ERIC Educational Resources Information Center

McDonald, Fiona J.; Reynolds, John N. J.; Bixley, Ann; Spronken-Smith, Rachel A.

2017-01-01

This study aimed to evaluate and compare approaches to learning by a longitudinal cohort of undergraduate students as they progressed from their first to third years of study in anatomy and physiology. "The Approaches and Study Skills Inventory for Students" (ASSIST) was completed at the beginning and end of their first year of…

Prevention of longitudinal crack propagation around a femoral prosthesis: a study of cerclage wire fixation.

PubMed

Difazio, F A; Incavo, S J; Howe, J D

1993-09-01

This study examined the effect of single versus triple-wrap cerclage fixation techniques in preventing propagation of a longitudinal fracture around a cementless femoral prosthesis. A proximal filling femoral component was implanted in 14 matched pairs of fresh-frozen bovine femora, following placement of a 45-mm longitudinal crack in the anteromedial cortical wall of the proximal femur. In one group of seven pairs, a single cerclage wire was applied to one specimen of each pair. A triple-wrap of a single cerclage wire was similarly placed in one specimen of each of the other seven pairs. All specimens were axially loaded on a materials testing system machine and the force required to propagate the fracture of the proximal femur was recorded. A triple-wrap cerclage technique required a significant increase in the force to propagate a proximal femur fracture around a non-cemented prosthesis when compared to a single cerclage wire. Copyright © 1993. Published by Elsevier Ltd.

Interaction of a shock with a longitudinal vortex

NASA Technical Reports Server (NTRS)

Erlebacher, Gordon; Hussaini, M. Y.; Shu, Chi-Wang

1996-01-01

In this paper we study the shock/longitudinal vortex interaction problem in axisymmetric geometry. Linearized analysis for small vortex strength is performed, and compared with results from a high order axisymmetric shock-fitted Euler solution obtained for this purpose. It is confirmed that for weak vortices, predictions from linear theory agree well with results from nonlinear numerical simulations at the shock location. To handle very strong longitudinal vortices, which may ultimately break the shock, we use an axisymmetric high order essentially non-oscillatory (ENO) shock capturing scheme. Comparison of shock-captured and shock-fitted results are performed in their regions of common validity. We also study the vortex breakdown as a function of Mach number ranging from 1.3 to 10, thus extending the range of existing results. For vortex strengths above a critical value. a triple point forms on the shock and a secondary shock forms to provide the necessary deceleration so that the fluid velocity can adjust to downstream conditions at the shock.

Suicidal risk in young adult offspring of mothers with bipolar or major depressive disorder: a longitudinal family risk study.

PubMed

Klimes-Dougan, Bonnie; Lee, Chih-Yuan S; Ronsaville, Donna; Martinez, Pedro

2008-04-01

Recent evidence has highlighted suicidal risk associated with bipolar disorder (BD). Using a family risk approach, the goal of this study was to evaluate suicidal thoughts and behaviors longitudinally from childhood to young adulthood in children of mothers with BD, Major depressive disorder (MDD), and well mothers. Few group differences were found for cross-sectional assessments of suicidal thoughts and behavior in young adulthood; the offspring of MDD demonstrate an earlier onset and more persistent suicidality than other groups, but by young adulthood, BD offspring appear to be comparable to MDD offspring in their rates of suicidality. The longitudinal assessments reveal a pattern of higher suicidal risk in MDD offspring, more intermediate risk in BD offspring, and lower risk in well offspring. Precursors and correlates of suicidal thoughts and behaviors were also examined. These findings suggest diverse developmental trajectories based on family risk and have implications for planning preventive intervention.

Feedback control laws for highly maneuverable aircraft

NASA Technical Reports Server (NTRS)

Garrard, William L.; Balas, Gary J.

1992-01-01

The results of a study of the application of H infinity and mu synthesis techniques to the design of feedback control laws for the longitudinal dynamics of the High Angle of Attack Research Vehicle (HARV) are presented. The objective of this study is to develop methods for the design of feedback control laws which cause the closed loop longitudinal dynamics of the HARV to meet handling quality specifications over the entire flight envelope. Control law designs are based on models of the HARV linearized at various flight conditions. The control laws are evaluated by both linear and nonlinear simulations of typical maneuvers. The fixed gain control laws resulting from both the H infinity and mu synthesis techniques result in excellent performance even when the aircraft performs maneuvers in which the system states vary significantly from their equilibrium design values. Both the H infinity and mu synthesis control laws result in performance which compares favorably with an existing baseline longitudinal control law.

Drug awareness in adolescents attending a mental health service: analysis of longitudinal data.

PubMed

Arnau, Jaume; Bono, Roser; Díaz, Rosa; Goti, Javier

2011-11-01

One of the procedures used most recently with longitudinal data is linear mixed models. In the context of health research the increasing number of studies that now use these models bears witness to the growing interest in this type of analysis. This paper describes the application of linear mixed models to a longitudinal study of a sample of Spanish adolescents attending a mental health service, the aim being to investigate their knowledge about the consumption of alcohol and other drugs. More specifically, the main objective was to compare the efficacy of a motivational interviewing programme with a standard approach to drug awareness. The models used to analyse the overall indicator of drug awareness were as follows: (a) unconditional linear growth curve model; (b) growth model with subject-associated variables; and (c) individual curve model with predictive variables. The results showed that awareness increased over time and that the variable 'schooling years' explained part of the between-subjects variation. The effect of motivational interviewing was also significant.

Doubly robust estimation of generalized partial linear models for longitudinal data with dropouts.

PubMed

Lin, Huiming; Fu, Bo; Qin, Guoyou; Zhu, Zhongyi

2017-12-01

We develop a doubly robust estimation of generalized partial linear models for longitudinal data with dropouts. Our method extends the highly efficient aggregate unbiased estimating function approach proposed in Qu et al. (2010) to a doubly robust one in the sense that under missing at random (MAR), our estimator is consistent when either the linear conditional mean condition is satisfied or a model for the dropout process is correctly specified. We begin with a generalized linear model for the marginal mean, and then move forward to a generalized partial linear model, allowing for nonparametric covariate effect by using the regression spline smoothing approximation. We establish the asymptotic theory for the proposed method and use simulation studies to compare its finite sample performance with that of Qu's method, the complete-case generalized estimating equation (GEE) and the inverse-probability weighted GEE. The proposed method is finally illustrated using data from a longitudinal cohort study. © 2017, The International Biometric Society.

Progression of MDS-UPDRS Scores Over Five Years in De Novo Parkinson Disease from the Parkinson's Progression Markers Initiative Cohort.

PubMed

Holden, Samantha K; Finseth, Taylor; Sillau, Stefan H; Berman, Brian D

2018-01-01

The Movement Disorder Society Unified Parkinson Disease Rating Scale (MDS-UDPRS) is a commonly used tool to measure Parkinson disease (PD) progression. Longitudinal changes in MDS-UPDRS scores in de novo PD have not been established. Determine progression rates of MDS-UPDRS scores in de novo PD. 362 participants from the Parkinson's Progression Markers Initiative, a multicenter longitudinal cohort study of de novo PD, were included. Longitudinal progression of MDS-UPDRS total and subscale scores were modeled using mixed model regression. MDS-UPDRS scores increased in a linear fashion over five years in de novo PD. MDS-UPDRS total score increased an estimated 4.0 points/year, Part I 0.25 points/year, Part II 1.0 points/year, and Part III 2.4 points/year. The expected average progression of MDS-UPDRS scores in de novo PD from this study can assist in clinical monitoring and provide comparative data for detection of disease modification in treatment trials.

Bipolar mood state reflected in cortico-amygdala resting state connectivity: A cohort and longitudinal study.

PubMed

Brady, Roscoe O; Margolis, Allison; Masters, Grace A; Keshavan, Matcheri; Öngür, Dost

2017-08-01

Using resting-state functional magnetic resonance imaging (rsfMRI), we previously compared cohorts of bipolar I subjects in a manic state to those in a euthymic state to identify mood state-specific patterns of cortico-amygdala connectivity. Our results suggested that mania is reflected in the disruption of emotion regulation circuits. We sought to replicate this finding in a group of subjects with bipolar disorder imaged longitudinally across states of mania and euthymia METHODS: We divided our subjects into three groups: 26 subjects imaged in a manic state, 21 subjects imaged in a euthymic state, and 10 subjects imaged longitudinally across both mood states. We measured differences in amygdala connectivity between the mania and euthymia cohorts. We then used these regions of altered connectivity to examine connectivity in the longitudinal bipolar group using a within-subjects design. Our findings in the mania vs euthymia cohort comparison were replicated in the longitudinal analysis. Bipolar mania was differentiated from euthymia by decreased connectivity between the amygdala and pre-genual anterior cingulate cortex. Mania was also characterized by increased connectivity between amygdala and the supplemental motor area, a region normally anti-correlated to the amygdala in emotion regulation tasks. Stringent controls for movement effects limited the number of subjects in the longitudinal sample. In this first report of rsfMRI conducted longitudinally across mood states, we find that previously observed between-group differences in amygdala connectivity are also found longitudinally within subjects. These results suggest resting state cortico-amygdala connectivity is a biomarker of mood state in bipolar disorder. Copyright © 2017 Elsevier B.V. All rights reserved.

Intraoperative performance and postoperative outcome comparison of longitudinal, torsional, and transversal phacoemulsification machines.

PubMed

Christakis, Panos G; Braga-Mele, Rosa M

2012-02-01

To compare the intraoperative performance and postoperative outcomes of 3 phacoemulsification machines that use different modes. Kensington Eye Institute, Toronto, Ontario, Canada. Comparative case series. This chart and video review comprised consecutive eligible patients who had phacoemulsification by the same surgeon using a Whitestar Signature Ellips-FX (transversal), Infiniti-Ozil-IP (torsional), or Stellaris (longitudinal) machine. The review included 98 patients. Baseline characteristics in the groups were similar; the mean nuclear sclerosis grade was 2.0 ± 0.8. There were no significant intraoperative complications. The torsional machine averaged less phacoemulsification needle time (83 ± 33 seconds) than the transversal (99 ± 40 seconds; P=.21) or longitudinal (110 ± 45 seconds; P=.02) machines; the difference was accentuated in cases with high-grade nuclear sclerosis. The torsional machine had less chatter and better followability than the transversal or longitudinal machines (P<.001). The torsional and longitudinal machines had better anterior chamber stability than the transversal machine (P<.001). Postoperatively, the torsional machine yielded less central corneal edema than the transversal (P<.001) and longitudinal (P=.04) machines, corresponding to a smaller increase in mean corneal thickness (torsional 5%, transversal 10%, longitudinal 12%; P=.04). Also, the torsional machine had better 1-day postoperative visual acuities (P<.001). All 3 phacoemulsification machines were effective with no significant intraoperative complications. The torsional machine outperformed the transversal and longitudinal machines, with a lower mean needle time, less chatter, and improved followability. This corresponded to less corneal edema 1 day postoperatively and better visual acuity. Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Longitudinal changes in gray matter regions after cranial radiation and comparative analysis with whole body radiation: a DTI study.

PubMed

Watve, Apurva; Gupta, Mamta; Khushu, Subash; Rana, Poonam

2018-06-01

Radiation-induced white matter changes are well known and vastly studied. However, radiation-induced gray matter alterations are still a research question. In the present study, these changes were assessed in a longitudinal manner using Diffusion Tensor Imaging (DTI) and further compared for cranial and whole body radiation exposure. Male mice (C57BL/6) were irradiated with cranial or whole body radiation followed by DTI study at 7T animal MRI system during predose, subacute and early delayed phases of radiation sickness. Fractional anisotropy (FA) and mean diffusivity (MD) values were obtained from brain's gray matter regions. Decreased FA with increased MD was observed prominently in animals exposed to cranial radiation showing most changes at 8 months post irradiation. However, whole body radiation induced FA changes were mostly observed at 1 month post irradiation as compared to controls. The differential response after whole body and cranial irradiation observed in the study depicts that radiation exposure of 5 Gy could induce permanent alterations in gray matter regions prominently as observed in Caudoputamen region at all the time points. Thus, our study has bolstered the role of DTI to probe microstructural changes in gray matter regions of brain after radiation exposure.

An empirical analysis of the public's attitudes toward advertising hospital services: a comparative cross-sectional study.

PubMed

Moser, H Ronald; Freeman, Gordon L

2014-01-01

This study investigates current opinions about hospital advertising and compares them to the attitudes expressed 25 years ago. It replicates a survey done in 1985, using the same questionnaire and population to compare responses longitudinally. The study indicates some changes in the public's opinions of hospital advertising. Although the image of hospitals remains positive, most of the 2010 respondents' opinions were rather mixed regarding whether it is proper for hospitals to advertise. The study also confirmed that the quality of service and reputation of hospitals remain more important to the public than price.

Longitudinal changes in body mass index of children affected by the Great East Japan Earthquake.

PubMed

Zheng, W; Yokomichi, H; Matsubara, H; Ishikuro, M; Kikuya, M; Isojima, T; Yokoya, S; Tanaka, T; Kato, N; Chida, S; Ono, A; Hosoya, M; Tanaka, S; Kuriyama, S; Kure, S; Yamagata, Z

2017-04-01

The evacuation and disruption in housing caused by the 2011 Great East Japan Earthquake and following nuclear radiation may have influenced child health in many respects. However, studies regarding longitudinal childhood growth are limited. Therefore, in this study we aimed to explore the influence of the earthquake on longitudinal changes in body mass index in preschool children. Participants were children from nursery schools who cooperated with the study in the Iwate, Miyagi and Fukushima prefectures. The exposed group consisted of children who experienced the earthquake during their preschool-age period (4-5 years old). The historical control group included children who were born 2 years earlier than the exposed children in the same prefectures. Trajectories regarding body mass index and prevalence of overweight/obesity were compared between the two groups using multilevel analysis. Differences in the changes in BMI between before and after the earthquake, and proportion of overweight/obesity was compared between the two groups. We also conducted subgroup analysis by defining children with specific personal disaster experiences within the exposed group. A total of 9722 children were included in the study. Children in the exposed group had higher body mass indices and a higher proportion of overweight after the earthquake than the control group. These differences were more obvious when confined to exposed children with specific personal disaster experiences. Children's growth and development-related health issues such as increased BMI after natural disasters should evoke great attention.

Predictors of Dental Care Use: Findings from the National Longitudinal Study of Adolescent Health

PubMed Central

Okunseri, Christopher; Okunseri, Elaye; Garcia, Raul I.; Visotcky, Alexis (Dye); Szabo, Aniko

2013-01-01

Objective To examine longitudinal trends and associated factors in dental service utilization by adolescents progressing to early adulthood in the United States. Data Source The National Longitudinal Study of Adolescent Health from Waves I (1994-95), II (1996), III (2001-2002) and IV (2007-2008). Study Design This is a retrospective, observational study of adolescents' transition to early adulthood. We obtained descriptive statistics and performed logistic regression analyses to identify the effects of baseline and concurrent covariates on dental service utilization from adolescence to early adulthood over time. Principal Findings Dental service utilization within the prior 12 months peaked at age 16 (72%), gradually decreased until age 21 (57%), and thereafter remained flat. Whites and Asians had a 10-20 percentage points higher proportion of dental service utilization at most ages compared to Blacks and Hispanics. Dental service utilization at later follow-up visits was strongly associated with baseline utilization with OR= 10.7, 2.4 and 1.5 at the 1-year, 7-year and 13-year follow-ups respectively. These effects decreased when adjusted for current income, insurance and education. Compared to Whites, Blacks were consistently less likely to report any dental examination. Conclusion Dental service utilization was highest in adolescents. Gender, education, health insurance and income in young adulthood were significant predictors of reporting a dental examination. Blacks had lower odds of reporting a dental examination either as adolescents or as young adults. PMID:23850156

The effect of unemployment on self-reported health and mental health in Greece from 2008 to 2013: a longitudinal study before and during the financial crisis.

PubMed

Drydakis, Nick

2015-03-01

The current study uses six annual waves of the Longitudinal Labor Market Study (LLMS) covering the 2008-2013 period to obtain longitudinal estimations suggesting statistically significant negative effects from unemployment on self-reported health and mental health in Greece. The specifications suggest that unemployment results in lower health and the deterioration of mental health during the 2008-2009 period compared with the 2010-2013 period, i.e., a period in which the country's unemployment doubled as a consequence of the financial crisis. Unemployment seems to be more detrimental to health/mental health in periods of high unemployment, suggesting that the unemployment crisis in Greece is more devastating as it concerns more people. Importantly, in all specifications, comparable qualitative patterns are found by controlling for unemployment due to firm closure, which allows us to minimize potential bias due to unemployment-health related reverse causality. Moreover, in all cases, women are more negatively affected by unemployment in relation to their health and mental health statuses than are men. Greece has been more deeply affected by the financial crisis than any other EU country, and this study contributes by offering estimates for before and during the financial crisis and considering causality issues. Because health and mental health indicators increase more rapidly in a context of higher surrounding unemployment, policy action must place greater emphasis on unemployment reduction and supporting women's employment. Copyright © 2014 Elsevier Ltd. All rights reserved.

Comparison of Segmental Versus Longitudinal Intravascular Ultrasound Analysis for Pediatric Cardiac Allograft Vasculopathy.

PubMed

Kuhn, M A; Burch, M; Chinnock, R E; Fenton, M J

2017-10-01

Intravascular ultrasound (IVUS) has been routinely used in some centers to investigate cardiac allograft vasculopathy in pediatric heart transplant recipients. We present an alternative method using more sophisticated imaging software. This study presents a comparison of this method with an established standard method. All patients who had IVUS performed in 2014 were retrospectively evaluated. The standard technique consisted of analysis of 10 operator-selected segments along the vessel. Each study was re-evaluated using a longitudinal technique, taken at every third cardiac cycle, along the entire vessel. Semiautomatic edge detection software was used to detect vessel imaging planes. Measurements included outer and inner diameter, total and luminal area, maximal intimal thickness (MIT), and intimal index. Each IVUS was graded for severity using the Stanford classification. All results were given as mean ± standard deviation (SD). Groups were compared using Student t test. A P value <.05 was considered significant. There were 59 IVUS studies performed on 58 patients. There was no statistically significant difference between outer diameter, inner diameter, or total area. In the longitudinal group, there was a significantly smaller luminal area, higher MIT, and higher intimal index. Using the longitudinal technique, there was an increase in Stanford classification in 20 patients. The longitudinal technique appeared more sensitive in assessing the degree of cardiac allograft vasculopathy and may play a role in the increase in the degree of thickening seen. It may offer an alternative way of grading severity of cardiac allograft vasculopathy in pediatric heart transplant recipients. Copyright © 2017 Elsevier Inc. All rights reserved.

High-resolution laser spectroscopy of hot Cs and Rb vapor confined in a thin optical cell

NASA Astrophysics Data System (ADS)

Todorov, P.; Krasteva, A.; Vartanyan, T.; Todorov, G.; Sarkisyan, D.; Cartaleva, S.

2018-03-01

We propose a novel use of an optical cell of micrometer thickness filled with Cs vapor in view of studying the collisions between two different alkali atoms of strongly different densities. We demonstrate narrow and good-contrast sub-Doppler resonances at the Rb D2 line for a mean-free-path of the Cs atoms comparable to the optical cell longitudinal dimension; the resonances are completely destroyed when the mean-free-path of the Cs atoms is more than two orders of magnitude shorter than the longitudinal dimension of the thin cell.

Brief Report: A Longitudinal Study of Excessive Smiling and Laughing in Children with Angelman Syndrome.

PubMed

Adams, Dawn; Horsler, Kate; Mount, Rebecca; Oliver, Chris

2015-08-01

Elevated laughing and smiling is a key characteristic of the Angelman syndrome behavioral phenotype, with cross-sectional studies reporting changes with environment and age. This study compares levels of laughing and smiling in 12 participants across three experimental conditions [full social interaction (with eye contact), social interaction with no eye contact, proximity only] at two data points. No differences were noted in frequency of laughing and smiling over time in any condition. However, with age as a covariate, the frequency of laughing and smiling decreased over time in the full social interaction (with eye contact) condition only. As this is the first longitudinal study to explore these behaviors in Angelman syndrome, the results suggest a gene-environment-time interaction within the behavioral phenotype.

Characterizing Design Cognition of High School Students: Initial Analyses Comparing Those with and without Pre-Engineering Experiences

ERIC Educational Resources Information Center

Wells, John; Lammi, Matthew; Gero, John; Grubbs, Michael E.; Paretti, Marie; Williams, Christopher

2016-01-01

Reported in this article are initial results from of a longitudinal study to characterize the design cognition and cognitive design styles of high school students with and without pre-engineering course experience over a 2-year period, and to compare them with undergraduate engineering students. The research followed a verbal protocol analysis…

Premature Discontinuation of Prospective Clinical Studies Approved by a Research Ethics Committee - A Comparison of Randomised and Non-Randomised Studies.

PubMed

Blümle, Anette; Schandelmaier, Stefan; Oeller, Patrick; Kasenda, Benjamin; Briel, Matthias; von Elm, Erik

2016-01-01

Premature discontinuation of clinical studies affects about 25% of randomised controlled trials (RCTs) which raises concerns about waste of scarce resources for research. The risk of discontinuation of non-randomised prospective studies (NPSs) is yet unclear. To compare the proportion of discontinued studies between NPSs and RCTs that received ethical approval. We systematically surveyed prospective longitudinal clinical studies that were approved by a single REC in Freiburg, Germany between 2000 and 2002. We collected study characteristics, identified subsequent publications, and surveyed investigators to elucidate whether a study was discontinued and, if so, why. Of 917 approved studies, 547 were prospective longitudinal studies (306 RCTs and 241 NPSs). NPSs were on average smaller than RCTs, more frequently single centre and pilot studies, and less frequently funded by industry. NPSs were less frequently discontinued than RCTs: 32/221 (14%) versus 78/288 (27%, p<0.001, missing data excluded). Poor recruitment was the most frequent reason for discontinuation in both NPSs (36%) and RCTs (37%). Compared to RCTs, NPSs were at lower risk for discontinuation. Measures to reliably predict, sustain, and stimulate recruitment could prevent discontinuation of many RCTs but also of some NPSs.

Exposure enriched outcome dependent designs for longitudinal studies of gene-environment interaction.

PubMed

Sun, Zhichao; Mukherjee, Bhramar; Estes, Jason P; Vokonas, Pantel S; Park, Sung Kyun

2017-08-15

Joint effects of genetic and environmental factors have been increasingly recognized in the development of many complex human diseases. Despite the popularity of case-control and case-only designs, longitudinal cohort studies that can capture time-varying outcome and exposure information have long been recommended for gene-environment (G × E) interactions. To date, literature on sampling designs for longitudinal studies of G × E interaction is quite limited. We therefore consider designs that can prioritize a subsample of the existing cohort for retrospective genotyping on the basis of currently available outcome, exposure, and covariate data. In this work, we propose stratified sampling based on summaries of individual exposures and outcome trajectories and develop a full conditional likelihood approach for estimation that adjusts for the biased sample. We compare the performance of our proposed design and analysis with combinations of different sampling designs and estimation approaches via simulation. We observe that the full conditional likelihood provides improved estimates for the G × E interaction and joint exposure effects over uncorrected complete-case analysis, and the exposure enriched outcome trajectory dependent design outperforms other designs in terms of estimation efficiency and power for detection of the G × E interaction. We also illustrate our design and analysis using data from the Normative Aging Study, an ongoing longitudinal cohort study initiated by the Veterans Administration in 1963. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Risky business: a longitudinal study examining cigarette smoking initiation among susceptible and non-susceptible e-cigarette users in Canada.

PubMed

Aleyan, Sarah; Cole, Adam; Qian, Wei; Leatherdale, Scott T

2018-05-26

Given that many adolescent e-cigarette users are never-smokers, the possibility that e-cigarettes may act as a gateway to future cigarette smoking has been discussed in various studies. Longitudinal data are needed to explore the pathway between e-cigarette and cigarette use, particularly among different risk groups including susceptible and non-susceptible never-smokers. The objective of this study was to examine whether baseline use of e-cigarettes among a sample of never-smoking youth predicted cigarette smoking initiation over a 2-year period. Longitudinal cohort study. 89 high schools across Ontario and Alberta, Canada. A sample of grade 9-11 never-smoking students at baseline (n=9501) who participated in the COMPASS study over 2 years. Participants completed in-class questionnaires that assessed smoking susceptibility and smoking initiation. Among the baseline sample of non-susceptible never-smokers, 45.2% of current e-cigarette users reported trying a cigarette after 2 years compared with 13.5% of non-current e-cigarette users. Among the baseline sample of susceptible never-smokers, 62.4% of current e-cigarette users reported trying a cigarette after 2 years compared with 36.1% of non-current e-cigarette users. Overall, current e-cigarette users were more likely to try a cigarette 2 years later. This association was stronger among the sample of non-susceptible never-smokers (AOR=5.28, 95% CI 2.81 to 9.94; p<0.0001) compared with susceptible never-smokers (AOR=2.78, 95% CI 1.84 to 4.20; p<0.0001). Findings from this large, longitudinal study support public health concerns that e-cigarette use may contribute to the development of a new population of cigarette smokers. They also support the notion that e-cigarettes are expanding the tobacco market by attracting low-risk youth who would otherwise be unlikely to initiate using cigarettes. Careful consideration will be needed in developing an appropriate regulatory framework that prevents e-cigarette use among youth. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Rasch Analyses of Very Low Food Security among Households and Children in the Three City Study*

PubMed Central

Moffitt, Robert A.; Ribar, David C.

2017-01-01

The longitudinal Three City Study of low-income families with children measures food hardships using fewer questions and some different questions from the standard U.S. instrument for measuring food security, the Household Food Security Survey Module (HFSSM) in the Current Population Survey (CPS). We utilize a Rasch measurement model to identify thresholds of very low food security among households and very low food security among children in the Three City Study that are comparable to thresholds from the HFSSM. We also use the Three City Study to empirically investigate the determinants of food insecurity and of these specific food insecurity outcomes, estimating a multivariate behavioral Rasch model that is adapted to address longitudinal data. The estimation results indicate that participation in the Supplemental Nutrition Assistance Program and the Temporary Assistance for Needy Families program reduce food insecurity, while poverty and disability among caregivers increase it. Besides its longitudinal structure, the Three City Study measures many more characteristics about households than the CPS. Our estimates reveal that financial assistance through social networks and a household's own financial assets reduce food insecurity, while its outstanding loans increase insecurity. PMID:29187764

Rasch Analyses of Very Low Food Security among Households and Children in the Three City Study.

PubMed

Moffitt, Robert A; Ribar, David C

2016-04-01

The longitudinal Three City Study of low-income families with children measures food hardships using fewer questions and some different questions from the standard U.S. instrument for measuring food security, the Household Food Security Survey Module (HFSSM) in the Current Population Survey (CPS). We utilize a Rasch measurement model to identify thresholds of very low food security among households and very low food security among children in the Three City Study that are comparable to thresholds from the HFSSM. We also use the Three City Study to empirically investigate the determinants of food insecurity and of these specific food insecurity outcomes, estimating a multivariate behavioral Rasch model that is adapted to address longitudinal data. The estimation results indicate that participation in the Supplemental Nutrition Assistance Program and the Temporary Assistance for Needy Families program reduce food insecurity, while poverty and disability among caregivers increase it. Besides its longitudinal structure, the Three City Study measures many more characteristics about households than the CPS. Our estimates reveal that financial assistance through social networks and a household's own financial assets reduce food insecurity, while its outstanding loans increase insecurity.

Vehicle longitudinal velocity estimation during the braking process using unknown input Kalman filter

NASA Astrophysics Data System (ADS)

Moaveni, Bijan; Khosravi Roqaye Abad, Mahdi; Nasiri, Sayyad

2015-10-01

In this paper, vehicle longitudinal velocity during the braking process is estimated by measuring the wheels speed. Here, a new algorithm based on the unknown input Kalman filter is developed to estimate the vehicle longitudinal velocity with a minimum mean square error and without using the value of braking torque in the estimation procedure. The stability and convergence of the filter are analysed and proved. Effectiveness of the method is shown by designing a real experiment and comparing the estimation result with actual longitudinal velocity computing from a three-axis accelerometer output.

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.

Expectations versus Reality: The Case of Liberal Studies in Hong Kong's New Senior Secondary Reforms

ERIC Educational Resources Information Center

Fung, Dennis

2016-01-01

This article reports the findings of a five-year longitudinal study investigating the introduction of Liberal Studies in the context of Hong Kong's new senior secondary educational reforms. The aim of this empirical research, which adopted diachronic analysis to allow comparisons over time, was to compare teachers' and students' perceptions of the…

The Reliability of Evidence Contained in the National Qualifications Framework Impact Study: A Critical Reflection--Research Article

ERIC Educational Resources Information Center

Higgs, Philip; Keevy, James

2007-01-01

This article reflects on the reliability of the evidence contained in the National Qualifications Framework Impact Study, a longitudinal comparative study conducted by the South African Qualifications Authority since 2002. In so doing, the veracity of evidence-based research in determining the impact of the South African Qualifications Framework…

A Population-Based Longitudinal Study of Depression in Children with Developmental Disabilities in Manitoba

ERIC Educational Resources Information Center

Shooshtari, Shahin; Brownell, Marni; Dik, Natalia; Chateau, Dan; Yu, C. T.; Mills, Rosemary S. L.; Burchill, Charles A.; Wetzel, Monika

2014-01-01

In this population-based study, prevalence of depression was estimated and compared between children with and without developmental disability (DD). Twelve years of administrative data were linked to identify a cohort of children with DD living in the Canadian province of Manitoba. Children in the study cohort were matched with children without DD…

Speech Characteristics of 8-Year-Old Children: Findings from a Prospective Population Study

ERIC Educational Resources Information Center

Wren, Yvonne; McLeod, Sharynne; White, Paul; Miller, Laura L.; Roulstone, Sue

2013-01-01

Speech disorder that continues into middle childhood is rarely studied compared with speech disorder in the early years. Speech production in single words, connected speech and nonword repetition was assessed for 7390 eight-year-old children within the Avon Longitudinal Study of Parents and Children (ALSPAC). The majority (n=6399) had typical…

Preparing for the Educational Black Hole? Teachers' Learning in Two Pathways into Middle School Social Studies Teaching

ERIC Educational Resources Information Center

Conklin, Hilary G.

2010-01-01

The author presents findings from the first phase of a longitudinal, comparative case study that investigates what teachers learn about intellectually demanding social studies teaching at the middle school level from two distinctive teacher education pathways: a specialized middle school teacher education program and a secondary social studies…

Defining SNAP by cross-sectional and longitudinal definitions of neurodegeneration.

PubMed

Wisse, L E M; Das, S R; Davatzikos, C; Dickerson, B C; Xie, S X; Yushkevich, P A; Wolk, D A

2018-01-01

Suspected non-Alzheimer's pathophysiology (SNAP) is a biomarker driven designation that represents a heterogeneous group in terms of etiology and prognosis. SNAP has only been identified by cross-sectional neurodegeneration measures, whereas longitudinal measures might better reflect "active" neurodegeneration and might be more tightly linked to prognosis. We compare neurodegeneration defined by cross-sectional 'hippocampal volume' only (SNAP/L-) versus both cross-sectional and longitudinal 'hippocampal atrophy rate' (SNAP/L+) and investigate how these definitions impact prevalence and the clinical and biomarker profile of SNAP in Mild Cognitive Impairment (MCI). 276 MCI patients from ADNI-GO/2 were designated amyloid "positive" (A+) or "negative" (A-) based on their florbetapir scan and neurodegeneration 'positive' or 'negative' based on cross-sectional hippocampal volume and longitudinal hippocampal atrophy rate. 74.1% of all SNAP participants defined by the cross-sectional definition of neurodegeneration also met the longitudinal definition of neurodegeneration, whereas 25.9% did not. SNAP/L+ displayed larger white matter hyperintensity volume, a higher conversion rate to dementia over 5 years and a steeper decline on cognitive tasks compared to SNAP/L- and the A- CN group. SNAP/L- had more abnormal values on neuroimaging markers and worse performance on cognitive tasks than the A- CN group, but did not show a difference in dementia conversion rate or longitudinal cognition. Using a longitudinal definition of neurodegeneration in addition to a cross-sectional one identifies SNAP participants with significant cognitive decline and a worse clinical prognosis for which cerebrovascular disease may be an important driver.

Longitudinal impact of IBS-type symptoms on disease activity, healthcare utilization, psychological health, and quality of life in inflammatory bowel disease.

PubMed

Gracie, David J; Hamlin, P John; Ford, Alexander C

2018-05-01

The impact of irritable bowel syndrome (IBS)-type symptoms on the natural history of inflammatory bowel disease (IBD) is uncertain. We aimed to address this in a longitudinal study of secondary care patients. Longitudinal disease activity was defined by disease flare, escalation of medical therapy, hospitalization, or intestinal resection. The number of investigations performed and clinics attended determined healthcare utilization. Psychological well-being and quality of life were assessed using validated questionnaires. These outcomes were compared over a minimum period of 2 years between patients reporting IBS-type symptoms and patients with quiescent disease, occult inflammation, and active disease at baseline. In 360 IBD patients, there were no differences in longitudinal disease activity between patients with IBS-type symptoms and patients with quiescent disease or occult inflammation. Disease flare and escalation of medical therapy was more common in patients with active disease than in patients with IBS-type symptoms (hazard ratio (HR) = 3.16; 95% confidence interval (CI) 1.93-5.19 and HR = 3.24; 95% CI 1.98-5.31, respectively). A greater number of investigations were performed in patients with IBS-type symptoms than quiescent disease (P = 0.008), but not compared with patients with occult inflammation or active disease. Anxiety, depression, and somatization scores at follow up were higher, and quality-of-life scores lower, in patients with IBS-type symptoms when compared with patients with quiescent disease, but were similar to patients with active disease. IBS-type symptoms in IBD were associated with increased healthcare utilization, psychological comorbidity, reduced quality of life, but not adverse disease activity outcomes during extended follow-up.

Longitudinal changes and correlations of bioimpedance and anthropometric measurements in pregnancy: Simple possible bed-side tools to assess pregnancy evolution.

PubMed

Piuri, Gabriele; Ferrazzi, Enrico; Bulfoni, Camilla; Mastricci, Luciana; Di Martino, Daniela; Speciani, Attilio Francesco

2017-12-01

The aim of this study was to assess longitudinal changes of bioimpedance analysis compared with anthropometric measurements in low-risk pregnant woman recruited in the first trimester and to observe possible differences in these indices in women who developed high-risk pregnancies. Bioimpedance indices for the three trimesters of pregnancies were calculated separately for uneventful pregnancies delivered of newborns > the 10th centile. These findings were compared with anthropometric measurements. Data of women who developed hypertensive disorders of pregnancy (HDP) or delivered SGA newborns were calculated and compared. Significantly longitudinal increases were observed in these pregnancies for total body water (TBW), free fat mass, fat mass, and extra-cellular water. These increases were paralleled body mass index (BMI), skinfolds, and waist measurements. The correlations between these two sets of findings were poor. Women who developed HDP with AGA fetuses showed significantly different bioimpedance from normal cases. TBW indices were highly significantly different since the first trimester. In pregnancies delivered of SGA newborns, these indices were opposite of the values observed in patients with HDP-AGA, TBW in these patients was significantly reduced compared with normal pregnancies. The bioelectrical impedance is a fast, simple, noninvasive way to assess the TBW content in pregnancy. Our findings are in agreement with the hypothesis that bioimpedance might help to identify early in gestation patients at risk of developing different clinical phenotypes of hypertensive disease of pregnancy and SGA fetuses.

A comparison of multiple imputation methods for handling missing values in longitudinal data in the presence of a time-varying covariate with a non-linear association with time: a simulation study.

PubMed

De Silva, Anurika Priyanjali; Moreno-Betancur, Margarita; De Livera, Alysha Madhu; Lee, Katherine Jane; Simpson, Julie Anne

2017-07-25

Missing data is a common problem in epidemiological studies, and is particularly prominent in longitudinal data, which involve multiple waves of data collection. Traditional multiple imputation (MI) methods (fully conditional specification (FCS) and multivariate normal imputation (MVNI)) treat repeated measurements of the same time-dependent variable as just another 'distinct' variable for imputation and therefore do not make the most of the longitudinal structure of the data. Only a few studies have explored extensions to the standard approaches to account for the temporal structure of longitudinal data. One suggestion is the two-fold fully conditional specification (two-fold FCS) algorithm, which restricts the imputation of a time-dependent variable to time blocks where the imputation model includes measurements taken at the specified and adjacent times. To date, no study has investigated the performance of two-fold FCS and standard MI methods for handling missing data in a time-varying covariate with a non-linear trajectory over time - a commonly encountered scenario in epidemiological studies. We simulated 1000 datasets of 5000 individuals based on the Longitudinal Study of Australian Children (LSAC). Three missing data mechanisms: missing completely at random (MCAR), and a weak and a strong missing at random (MAR) scenarios were used to impose missingness on body mass index (BMI) for age z-scores; a continuous time-varying exposure variable with a non-linear trajectory over time. We evaluated the performance of FCS, MVNI, and two-fold FCS for handling up to 50% of missing data when assessing the association between childhood obesity and sleep problems. The standard two-fold FCS produced slightly more biased and less precise estimates than FCS and MVNI. We observed slight improvements in bias and precision when using a time window width of two for the two-fold FCS algorithm compared to the standard width of one. We recommend the use of FCS or MVNI in a similar longitudinal setting, and when encountering convergence issues due to a large number of time points or variables with missing values, the two-fold FCS with exploration of a suitable time window.

Shoe midsole longitudinal bending stiffness and running economy, joint energy, and EMG.

PubMed

Roy, Jean-Pierre R; Stefanyshyn, Darren J

2006-03-01

It has been shown that mechanical energy is dissipated at the metatarsophalangeal (MTP) joint during running and jumping. Furthermore, increasing the longitudinal bending stiffness of the midsole significantly reduced the energy dissipated at the MTP joint and increased jump performance. It was hypothesized that increasing midsole longitudinal bending stiffness would also lead to improvements in running economy. This study investigated the influence of midsole longitudinal bending stiffness on running economy (performance variable) and evaluated the local effects on joint energetics and muscular activity. Carbon fiber plates were inserted into running shoe midsoles and running economy, joint energy, and electromyographic (EMG) data were collected on 13 subjects. Approximately a 1% metabolic energy savings was observed when subjects ran in a stiff midsole relative to the control midsole. Subjects with a greater body mass had a greater decrease in oxygen consumption rates in the stiff midsole relative to the control midsole condition. The stiffer midsoles showed no significant differences in energy absorption at the MTP joint compared with the control shoe. Finally, no significant changes were observed in muscular activation. Increasing midsole longitudinal bending stiffness led to improvements in running economy, yet the underlying mechanisms that can be attributed to this improvement are still not fully understood.

Selecting a Separable Parametric Spatiotemporal Covariance Structure for Longitudinal Imaging Data

PubMed Central

George, Brandon; Aban, Inmaculada

2014-01-01

Longitudinal imaging studies allow great insight into how the structure and function of a subject’s internal anatomy changes over time. Unfortunately, the analysis of longitudinal imaging data is complicated by inherent spatial and temporal correlation: the temporal from the repeated measures, and the spatial from the outcomes of interest being observed at multiple points in a patients body. We propose the use of a linear model with a separable parametric spatiotemporal error structure for the analysis of repeated imaging data. The model makes use of spatial (exponential, spherical, and Matérn) and temporal (compound symmetric, autoregressive-1, Toeplitz, and unstructured) parametric correlation functions. A simulation study, inspired by a longitudinal cardiac imaging study on mitral regurgitation patients, compared different information criteria for selecting a particular separable parametric spatiotemporal correlation structure as well as the effects on Type I and II error rates for inference on fixed effects when the specified model is incorrect. Information criteria were found to be highly accurate at choosing between separable parametric spatiotemporal correlation structures. Misspecification of the covariance structure was found to have the ability to inflate the Type I error or have an overly conservative test size, which corresponded to decreased power. An example with clinical data is given illustrating how the covariance structure procedure can be done in practice, as well as how covariance structure choice can change inferences about fixed effects. PMID:25293361

Temperament in the developmental course: a longitudinal comparison of New York Longitudinal Study-derived dimensions with the Junior Temperament and Character Inventory.

PubMed

Pitzer, Martina; Esser, Guenter; Schmidt, Martin H; Laucht, Manfred

2007-01-01

Despite theoretical discrepancies between different concepts of temperament, some core dimensions are thought to be common to the various models. We compared temperamental traits derived from the New York Longitudinal Study (NYLS) model and the Cloninger dimensions in the developmental course and investigated the associations of temperament with sex as well as with obstetric risks or psychosocial risks present at birth. Participants were 151 boys and 157 girls born at differing degrees of obstetric and psychosocial risk from a longitudinal study on a high-risk community sample. In infancy and childhood, NYLS-derived temperamental characteristics were assessed by a highly structured parent interview and standardized behavioral observations. At age 15 years, the Junior Temperament and Character Inventory/12-18 was administered. Moderate correlations were found between Junior Temperament and Character Inventory scales in adolescence and NYLS-derived factors in childhood. The psychosocial risk load seemed to influence the expression of novelty seeking or corresponding NYLS-derived factors, whereas the obstetric risks did not contribute to variation in temperament. Our findings further support highly sex-specific gene x environment interactions on temperament in the developmental course. The content of our NYLS-derived factors and the specific type of association across different temperament constructs fit into the increasing consensus regarding a small number of higher-order temperamental traits.

New Methods to Address Old Challenges: The Use of Administrative Data for Longitudinal Replication Studies of Child Maltreatment

PubMed Central

Hurren, Emily; Stewart, Anna; Dennison, Susan

2017-01-01

Administrative data are crucial to the “big data” revolution of social science and have played an important role in the development of child maltreatment research. These data are also of value to administrators, policy makers, and clinicians. The focus of this paper is the use of administrative data to produce and replicate longitudinal studies of child maltreatment. Child protection administrative data have several advantages. They are often population-based, and allow longitudinal examination of child maltreatment and complex multi-level analyses. They also allow comparison across subgroups and minority groups, remove burden from individuals to disclose traumatic experiences, and can be less biased than retrospective recall. Finally, they can be linked to data from other agencies to explore comorbidity and outcomes, and are comparatively cost and time effective. The benefits and challenges associated with the use of administrative data for longitudinal child maltreatment research become magnified when these data are used to produce replications. Techniques to address challenges and support future replication efforts include developing a biographical understanding of the systems from which the data are drawn, using multiple data sources to contextualize the data and research results, recognizing and adopting various approaches to replication, and documenting all data coding and manipulation processes. These techniques are illustrated in this paper via a case study of previous replication work. PMID:28914775

New Methods to Address Old Challenges: The Use of Administrative Data for Longitudinal Replication Studies of Child Maltreatment.

PubMed

Hurren, Emily; Stewart, Anna; Dennison, Susan

2017-09-15

Administrative data are crucial to the "big data" revolution of social science and have played an important role in the development of child maltreatment research. These data are also of value to administrators, policy makers, and clinicians. The focus of this paper is the use of administrative data to produce and replicate longitudinal studies of child maltreatment. Child protection administrative data have several advantages. They are often population-based, and allow longitudinal examination of child maltreatment and complex multi-level analyses. They also allow comparison across subgroups and minority groups, remove burden from individuals to disclose traumatic experiences, and can be less biased than retrospective recall. Finally, they can be linked to data from other agencies to explore comorbidity and outcomes, and are comparatively cost and time effective. The benefits and challenges associated with the use of administrative data for longitudinal child maltreatment research become magnified when these data are used to produce replications. Techniques to address challenges and support future replication efforts include developing a biographical understanding of the systems from which the data are drawn, using multiple data sources to contextualize the data and research results, recognizing and adopting various approaches to replication, and documenting all data coding and manipulation processes. These techniques are illustrated in this paper via a case study of previous replication work.

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

PubMed

Ellis, Sam; Reader, Andrew J

2018-04-26

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

Developing Fair Tests for Mathematics Curriculum Comparison Studies: The Role of Content Analyses

ERIC Educational Resources Information Center

Chavez, Oscar; Papick, Ira; Ross, Daniel J.; Grouws, Douglas A.

2011-01-01

This article describes the process of development of assessment instruments for a three-year longitudinal comparative study that focused on evaluating American high school students' mathematics learning from two distinct approaches to content organization: curriculum built around a sequence of three full-year courses (Algebra 1, Geometry, and…

Early infant diet and ERP Correlates of Speech Stimuli Discrimination in 9 month old infants

USDA-ARS?s Scientific Manuscript database

Processing and discrimination of speech stimuli were examined during the initial period of weaning in infants enrolled in a longitudinal study of infant diet and development (the Beginnings Study). Event-related potential measures (ERP; 128 sites) were used to compare the processing of speech stimul...

Change in Posttraumatic Stress Disorder Symptoms: Do Clinicians and Patients Agree?

ERIC Educational Resources Information Center

Monson, Candice M.; Gradus, Jaimie L.; Young-Xu, Yinong; Schnurr, Paula P.; Price, Jennifer L.; Schumm, Jeremiah A.

2008-01-01

This study assessed the longitudinal association between clinician and patient ratings of posttraumatic stress disorder (PTSD) symptoms over the course of 2 different randomized clinical trials of veterans with chronic PTSD. One trial, the Department of Veterans Affairs Cooperative Study 420 (CSP 420; N = 360) compared trauma-focused and…

Effects of a Paired Literacy Program on Emerging Bilingual Children's Biliteracy Outcomes in Third Grade

ERIC Educational Resources Information Center

Soltero-González, Lucinda; Sparrow, Wendy; Butvilofsky, Sandra; Escamilla, Kathy; Hopewell, Susan

2016-01-01

This longitudinal study examined whether the implementation of a Spanish-English paired literacy approach provides an academic advantage to emerging bilingual students over a sequential literacy approach. The study employed a quasi-experimental design. It compared the biliteracy outcomes of third-grade emerging bilingual learners participating in…

School Stratification in New and Established Latino Destinations

ERIC Educational Resources Information Center

Dondero, Molly; Muller, Chandra

2012-01-01

The growth and geographic diversification of the school-age Latino population suggest that schools in areas that previously had very few Latinos now serve many of these students. This study uses the 1999-2000 Schools and Staffing Survey and the Education Longitudinal Study of 2002 to compare public high schools in new and established Latino…

The Development of Color Categories in Two Languages: A Longitudinal Study

ERIC Educational Resources Information Center

Roberson, Debi; Davidoff, Jules; Davies, Ian R. L.; Shapiro, Laura R.

2004-01-01

This study unites investigations into the linguistic relativity of color categories with research on children's category acquisition. Naming, comprehension, and memory for colors were tracked in 2 populations over a 3-year period. Children from a seminomadic equatorial African culture, whose language contains 5 color terms, were compared with a…

Subsidized Housing, Public Housing, and Adolescent Violence and Substance Use

ERIC Educational Resources Information Center

Leech, Tamara G. J.

2012-01-01

This study examines the separate relationships of public housing residence and subsidized housing residence to adolescent health risk behavior. Data include 2,530 adolescents aged 14 to 19 who were children of the National the Longitudinal Study of Youth. The author used stratified propensity methods to compare the behaviors of each…

Stability, Correlates, and Outcome of Adolescent Suicidal Risk

ERIC Educational Resources Information Center

Steinhausen, Hans-Christoph; Bosiger, Ruth; Metzke, Christa Winkler

2006-01-01

Background: The goal of this study was to investigate the stability and correlates of adolescent suicidal risk across adolescence. Methods: Suicidal risk was studied longitudinally in N = 593 subjects in 1994, 1997, and 2001 at mean ages of 13, 16, and 20 years. Three partly overlapping suicidal risk groups were compared to three control groups…

Childhood Onset Schizophrenia: Cortical Brain Abnormalities as Young Adults

ERIC Educational Resources Information Center

Greenstein, Deanna; Lerch, Jason; Shaw, Philip; Clasen, Liv; Giedd, Jay; Gochman, Peter; Rapoport, Judith; Gogtay, Nitin

2006-01-01

Background: Childhood onset schizophrenia (COS) is a rare but severe form of the adult onset disorder. While structural brain imaging studies show robust, widespread, and progressive gray matter loss in COS during adolescence, there have been no longitudinal studies of sufficient duration to examine comparability with the more common adult onset…

An Initial Investigation of Sexual Minority Youth Involvement in School-Based Extracurricular Activities

ERIC Educational Resources Information Center

Toomey, Russell B.; Russell, Stephen T.

2013-01-01

Sexual minority youth are at risk for negative school-based experiences and poor academic outcomes. Yet, little is known about their experiences in positive school-based contexts. Using the "National Longitudinal Study of Adolescent Health" (1,214 sexual minority and 11,427 heterosexual participants), this study compared participation…

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…

Advances in Research on Organization Development: Toward a Beginning

ERIC Educational Resources Information Center

Pate, Larry E.; And Others

1977-01-01

This paper examines 38 research studies that were conducted on various aspects of organization development (OD) technology. The studies are compared along eight dimensions. Problems associated with evaluating OD and the limited amount of OD research are discussed. It is argued that more systematic, longitudinal research on OD is needed. (Author)

Identification of Student- and Teacher-Level Variables in Modeling Variation of Mathematics Achievement Data

ERIC Educational Resources Information Center

Tarr, James E.; Ross, Daniel J.; McNaught, Melissa D.; Chavez, Oscar; Grouws, Douglas A.; Reys, Robert E.; Sears, Ruthmae; Taylan, R. Didem

2010-01-01

The Comparing Options in Secondary Mathematics: Investigating Curriculum (COSMIC) project is a longitudinal study of student learning from two types of mathematics curricula: integrated and subject-specific. Previous large-scale research studies such as the National Assessment of Educational Progress (NAEP) indicate that numerous variables are…

A Neurophysiological Marker of Impaired Preparation in an 11-Year Follow-Up Study of Attention-Deficit/Hyperactivity Disorder (ADHD)

ERIC Educational Resources Information Center

Doehnert, Mirko; Brandeis, Daniel; Schneider, Gudrun; Drechsler, Renate; Steinhausen, Hans-Christoph

2013-01-01

Background: This longitudinal electrophysiological study investigated the course of multiple impaired cognitive brain functions in attention-deficit/hyperactivity disorder (ADHD) from childhood to adulthood by comparing developmental trajectories of individuals with ADHD and typically developing controls. Methods: Subjects with ADHD ("N"…

77 FR 26773 - Agency Information Collection Activities: Proposed Collection; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-07

... enhanced and standard data collection and a longitudinal cohort design, and will include a comparative study to assess the effectiveness of HTI relative to a similar sample of young persons who did not... total hourly cost of the study. Summary Burden Table Average annual Average 3-year Number of number...

Links between Children's Clay Models and School Achievement.

ERIC Educational Resources Information Center

Bezruczko, Nikolaus

Two studies examined the relationship between children's clay models and the children's concurrent school achievement, and compared a 6-year longitudinal record of achievement test scores for one cohort of students at schools that did or did not provide visual arts instruction. Participating in Study 1 were 201 kindergartners and third graders…

Longitudinal Study of Catholic College Undergraduates' Affiliation and Faith Development.

ERIC Educational Resources Information Center

White, Voncile

Faith stage development of Catholic college seniors was compared with their levels of denominational affiliation as a follow-up of a similar study of the students during their sophomore year. The students were male and female dormitory residents from the liberal arts and business schools of an eastern Catholic university. Affiliation was defined…

Midlife Impacts of Adolescent Parenthood

ERIC Educational Resources Information Center

Taylor, Julie Lounds

2009-01-01

The present study examined the midlife outcomes of 548 adults who became parents before the age of 20. Participants were from the Wisconsin Longitudinal Study (WLS) and were followed prospectively from age 18 until age 53. Their life-course development was compared to sample members who gave birth at the mean age for the WLS. Midlife outcomes were…

Family structure and child food insecurity.

PubMed

Miller, Daniel P; Nepomnyaschy, Lenna; Ibarra, Gabriel Lara; Garasky, Steven

2014-07-01

We examined whether food insecurity was different for children in cohabiting or repartnered families versus those in single-mother or married-parent (biological) families. We compared probabilities of child food insecurity (CFI) across different family structures in 4 national data sets: the Early Childhood Longitudinal Study-Birth Cohort (ECLS-B), the Fragile Families and Child Wellbeing Study (FFCWS), the Early Childhood Longitudinal Study-Kindergarten Cohort (ECLS-K), and the Panel Study of Income Dynamics-Child Development Supplement (PSID-CDS). Unadjusted probabilities of CFI in cohabiting or repartnered families were generally higher than in married-biological-parent families and often statistically indistinguishable from those of single-mother families. However, after adjustment for sociodemographic factors, most differences between family types were attenuated and most were no longer statistically significant. Although children whose biological parents are cohabiting or whose biological mothers have repartnered have risks for food insecurity comparable to those in single-mother families, the probability of CFI does not differ by family structure when household income, family size, and maternal race, ethnicity, education, and age were held at mean levels.

Three-dimensional Speckle Tracking Echocardiography in Light Chain Cardiac Amyloidosis: Examination of Left and Right Ventricular Myocardial Mechanics Parameters.

PubMed

Urbano-Moral, Jose Angel; Gangadharamurthy, Dakshin; Comenzo, Raymond L; Pandian, Natesa G; Patel, Ayan R

2015-08-01

The study of myocardial mechanics has a potential role in the detection of cardiac involvement in patients with amyloidosis. This study aimed to characterize 3-dimensional-speckle tracking echocardiography-derived left and right ventricular myocardial mechanics in light chain amyloidosis and examine their relationship with brain natriuretic peptide. In patients with light chain amyloidosis, left ventricular longitudinal and circumferential strain (n=40), and right ventricular longitudinal strain and radial displacement (n=26) were obtained by 3-dimensional-speckle tracking echocardiography. Brain natriuretic peptide levels were determined. All myocardial mechanics measurements showed differences when compared by brain natriuretic peptide level tertiles. Left and right ventricular longitudinal strain were highly correlated (r=0.95, P<.001). Left ventricular longitudinal and circumferential strain were reduced in patients with cardiac involvement (-9±4 vs -16±2; P<.001, and -24±6 vs -29±4; P=.01, respectively), with the most prominent impairment at the basal segments. Right ventricular longitudinal strain and radial displacement were diminished in patients with cardiac involvement (-9±3 vs -17±3; P<.001, and 2.7±0.8 vs 3.8±0.3; P=.002). On multivariate analysis, left ventricular longitudinal strain was associated with the presence of cardiac involvement (odds ratio = 1.6; 95% confidence interval, 1.04 to 2.37; P=.03) independent of the presence of brain natriuretic peptide and troponin I criteria for cardiac amyloidosis. Three-dimensional-speckle tracking echocardiography-derived left and right ventricular myocardial mechanics are increasingly altered as brain natriuretic peptide increases in light chain amyloidosis. There appears to be a strong association between left ventricular longitudinal strain and cardiac involvement, beyond biomarkers such as brain natriuretic peptide and troponin I. Copyright © 2015 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Abnormal skeletal growth patterns in adolescent idiopathic scoliosis--a longitudinal study until skeletal maturity.

PubMed

Yim, Annie P Y; Yeung, Hiu-Yan; Hung, Vivian W Y; Lee, Kwong-Man; Lam, Tsz-Ping; Ng, Bobby K W; Qiu, Yong; Cheng, Jack C Y

2012-08-15

A cross-sectional and prospective longitudinal study on the anthropometric parameters and growth pattern of girls with adolescent idiopathic scoliosis (AIS). To investigate the growth pattern of girls with AIS with different severities, using cross-sectional and prospective longitudinal data set in comparison with age-matched healthy controls. AIS occurs in children during their pubertal growth spurt. Although there is no clear consensus on the difference in body height between girls with AIS and healthy controls, it is generally thought that the development and curve progression in girls with AIS is closely associated with their growth rate. There is no concrete prospective longitudinal study to document clearly the growth pattern and growth rate of subjects with AIS . A total of 611 girls with AIS and 296 healthy age-matched controls were included in the study and among them, 194 girls with AIS and 116 healthy controls were followed up until skeletal maturity. The girls with AIS were grouped into moderate (AIS20) and severe curve (AIS40) groups on the basis of maximum curve magnitude at skeletal maturity. Clinical data and detailed anthropometric parameters were recorded. In the cross-sectional analysis, the groups of subjects were compared within different age groups (from the age of 12-16 yr). In the longitudinal study, linear mixed modeling with respect to age or years since menarche was employed to formulate the growth trajectory of different anthropometric parameters. In the cross-sectional analysis, the girls with AIS were generally taller, with longer arm span and lower body mass index than the healthy controls. The girls with AIS40 were found to be significantly shorter in height (P = 0.006) and arm span (P = 0.025) at the age of 12 years but caught up and overtook the control group at the age of 14 to 16 years. In the longitudinal study, the average growth rate of arm span in girls with AIS40 was significantly higher than that in girls with AIS20 (> 30%) (P = 0.004) and controls (> 70%) (P = 0.0004). The age of menarche of girls with AIS40 was significantly delayed by 5.9 months and 3.8 months when compared with the control group and girls with AIS20, respectively (P < 0.05). The growth patterns of girls with AIS with confirmed curve severities were significantly different from healthy age-matched controls. Girls with severe AIS had delayed menarche with faster skeletal growth rate during the age of 12 to 16 years. Monitoring the rate of change of arm span of girls with AIS could be an important additional clinical parameter in helping predict curve severity in girls with AIS.

College Students' Goals, Plans, and Background Characteristics; A Synthesis of Three Empirical Studies.

ERIC Educational Resources Information Center

Fenske, Robert H.; Scott, Craig S.

This study was designed to provide longitudinal data bearing on the change and/or stability of college-bound students' educational and vocational goals, as well as their background characteristics. Data from three studies were contrasted and compared. Included in these studies were: (1) a 2-year followup of 4,009 junior college students; (2) a…

Longitudinal, 3D Imaging of Collagen Remodeling in Murine Hypertrophic Scars In Vivo using Polarization-sensitive Optical Frequency Domain Imaging

PubMed Central

Lo, William C. Y.; Villiger, Martin; Golberg, Alexander; Broelsch, G. Felix; Khan, Saiqa; Lian, Christine G.; Austen, William G.; Yarmush, Martin; Bouma, Brett E.

2016-01-01

Hypertrophic scars (HTS), frequently seen after traumatic injuries and surgery, remain a major clinical challenge due to the limited success of existing therapies. A significant obstacle to understanding HTS etiology is the lack of tools to monitor scar remodeling longitudinally and non-invasively. We present an in vivo, label-free technique using polarization-sensitive optical frequency domain imaging (PS-OFDI) for the 3D, longitudinal assessment of collagen remodeling in murine HTS. In this study, HTS was induced with a mechanical tension device for 4 to 10 days on incisional wounds and imaged up to one month after device removal; an excisional HTS model was also imaged at 6 months after injury to investigate deeper and more mature scars. We showed that local retardation (LR) and degree of polarization (DOP) provide a robust signature for HTS. Compared to normal skin with heterogeneous LR and low DOP, HTS was characterized by an initially low LR, which increased as collagen fibers remodeled, and a persistently high DOP. This study demonstrates that PS-OFDI offers a powerful tool to gain significant biological insights into HTS remodeling by enabling longitudinal assessment of collagen in vivo, which is critical to elucidating HTS etiology and developing more effective HTS therapies. PMID:26763427

Sexual Minority Disparities in Substance Use Willingness Among Youth.

PubMed

Gamarel, Kristi E; Mereish, Ethan H; Colby, Suzanne M; Barnett, Nancy P; Hayes, Kerri; Jackson, Kristina M

2018-01-02

Disparities in substance use have been observed in sexual minority youth, but less is known about willingness to use substances, an important precursor to actual use. The goal of this study was to examine willingness to use cigarettes, alcohol, and marijuana among sexual minority youth compared to their non-sexual minority counterparts using both cross-sectional and longitudinal data. The present study drew on two waves (Times 1 and 2; 6 months apart) of data collected during high school as part of a prospective study of substance use initiation and progression in Rhode Island. At Time 1, participants (N = 443) ranged in age from 15 to 20 years (M age = 16.7 years, 26.6% sexual minority, 59.5% female, 72.0% White). Participants self-reported their sexual identity and attraction, lifetime use of alcohol, cigarettes and marijuana, and cigarette, alcohol, and marijuana use willingness (i.e., if offered by a best friend or group of friends). In cross-sectional multivariate regression models, sexual minority youth were more likely to report willingness to use cigarettes (p <.05) and marijuana (p <.01) compared to their non-sexual minority counterparts. Longitudinal multivariate regression models revealed that sexual minorities were only significantly more likely to report cigarette willingness at Time 2 compared to their non-sexual minority counterparts (p <.01). There were no significant differences in alcohol use willingness in multivariable cross-sectional or longitudinal models by sexual minority status. Sexual minority youth reported more willingness than non-sexual minority youth to use substances offered by peers; however, longitudinal analyses revealed that peers appear to play a role only in willingness to smoke cigarettes for these youth, and thus peer influence may be a contributing factor in explaining tobacco-related disparities among sexual minority youth. Given that stigma and peer groups may a particular risk factor for tobacco among sexual minority youth, our findings highlight the importance of prevention programs such as social marketing approaches that correct social norms, reduce stigma, and provide refusal-skills training to reduce tobacco-related disparities among sexual minorities.

Spontaneous myometrial contractility in cows suffering from endometritis-Influence of localisation, smooth muscle layer and cycle phase. An in vitro study.

PubMed

Hirsbrunner, Gaby; Kaufmann, Ch; Keller, Ch; Hüsler, J; Steiner, A

2010-04-01

Contractility of the healthy bovine myometrium depends on the reproductive state. Furthermore, contractility is influenced by localisation and the direction of smooth muscle strips. However, little is known about the contractile behaviour of the uterus when affected by endometritis. In our study, myometrial specimens from the larger horn (near the corpus and near the tip) in cows suffering from endometritis in estrus (n=8) or diestrus (n=8) were collected after slaughter. Two strips were prepared from each region corresponding to the circular and the longitudinal muscle layers, respectively. The spontaneous contractility of these strips was recorded in an organ bath. To analyse the results, the 2.5h recordings were divided into five periods of 30 min each. The variables area under curve (AUC) and maximal (A(max)) and minimal amplitude (A(min)) were calculated separately for each period, and the results were analysed using a non-parametric model regarding the influence of cycle phase (estrus vs. diestrus), region (corpus vs. tip) and muscle layer (circular vs. longitudinal). The values of both AUC and A(max) increased significantly over time. Muscle layer had a significant effect on AUC (corpus, tip) and A(max) (tip): the values of circular layers were increased compared to longitudinal layers. Dividing the data into subgroups allowed us to analyse them additionally according to muscle layer: In longitudinal layers, A(max) was increased at the corpus as compared with the tip. In this model, the factor cycle phase did not produce any significant difference in spontaneous myometrial activity. However, data of all variables showed non-significant higher values in estrus than in diestrus samples. Copyright 2009 Elsevier B.V. All rights reserved.

Ventrolateral Motor Thalamus Abnormal Connectivity in Essential Tremor Before and After Thalamotomy: A Resting-State Functional Magnetic Resonance Imaging Study.

PubMed

Tuleasca, Constantin; Najdenovska, Elena; Régis, Jean; Witjas, Tatiana; Girard, Nadine; Champoudry, Jérôme; Faouzi, Mohamed; Thiran, Jean-Philippe; Cuadra, Meritxell Bach; Levivier, Marc; Van De Ville, Dimitri

2018-05-01

To evaluate functional connectivity (FC) of the ventrolateral thalamus, a common target for drug-resistant essential tremor (ET), resting-state data were analyzed before and 1 year after stereotactic radiosurgical thalamotomy and compared against healthy controls (HCs). In total, 17 consecutive patients with ET and 10 HCs were enrolled. Tremor network was investigated using the ventrolateral ventral (VLV) thalamic nucleus as the region of interest, extracted with automated segmentation from pretherapeutic diffusion magnetic resonance imaging. Temporal correlations of VLV at whole brain level were evaluated by comparing drug-naïve patients with ET with HCs, and longitudinally, 1 year after stereotactic radiosurgical thalamotomy. 1 year thalamotomy MR signature was always located inside VLV and did not correlate with any of FC measures (P > 0.05). This suggested presence of longitudinal changes in VLV FC independently of the MR signature volume. Pretherapeutic ET displayed altered VLV FC with left primary sensory-motor cortex, pedunculopontine nucleus, dorsal anterior cingulate, left visual association, and left superior parietal areas. Pretherapeutic negative FC with primary somatosensory cortex and pedunculopontine nucleus correlated with poorer baseline tremor scores (Spearman = 0.04 and 0.01). Longitudinal study displayed changes within right dorsal attention (frontal eye-fields and posterior parietal) and salience (anterior insula) networks, as well as areas involved in hand movement planning or language production. Our results demonstrated that patients with ET and HCs differ in their left VLV FC to primary somatosensory and supplementary motor, visual association, or brainstem areas (pedunculopontine nucleus). Longitudinal changes display reorganization of dorsal attention and salience networks after thalamotomy. Beside attentional gateway, they are also known for their major role in facilitating a rapid access to the motor system. Copyright © 2018 Elsevier Inc. All rights reserved.

Sexual Behavior and Contraceptive Use among 18- to 19-Year-Old Adolescent Women by Weight Status: A Longitudinal Analysis.

PubMed

Chang, Tammy; Davis, Matthew M; Kusunoki, Yasamin; Ela, Elizabeth J; Hall, Kelli S; Barber, Jennifer S

2015-09-01

To describe the association between weight status and sexual practices among 18- to 19-year-old women. We analyzed a population-based longitudinal study of 18- to 19-year-old women residing in a Michigan county at cohort inception. Weekly journal surveys measured sexual practices, including contraceptive behaviors. Outcomes included proportion of weeks with a partner, proportion of weeks with sexual intercourse, number of partners, average length of relationships, proportion of weeks with contraception use, and proportion of weeks where contraception was used consistently. We examined 26,545 journal surveys from 900 women over the first study year. Ordinary least squares regression models for each outcome examined differences by weight status, controlling for sociodemographic characteristics. The mean proportion of weeks in which adolescents reported sexual intercourse was 52%; there was no difference by weight status. Among weeks in which adolescents reported sexual activity, obese adolescents had a lower proportion of weeks where any contraception was used compared with normal weight adolescents (84% vs 91%, P = .011). Among weeks in which adolescents reported sexual activity and contraceptive use, obese adolescents had a lower proportion of weeks with consistent contraceptive use (68% vs 78%, P = .016) and oral contraceptive pill use (27% vs 45%, P = .001) compared with normal weight adolescents. All other relationships by weight status were not statistically significant. In this longitudinal study, obese adolescent women were less likely to use contraception, and less likely to use it consistently when compared with normal weight peers. Findings suggest obesity may be an important factor associated with adolescent women's sexual behavior. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Long-Term Changes in Adiposity and Glycemic Control Are Associated With Past Adenovirus Infection

PubMed Central

Lin, Wan-Yu; Dubuisson, Olga; Rubicz, Rohina; Liu, Nianjun; Allison, David B.; Curran, Joanne E.; Comuzzie, Anthony G.; Blangero, John; Leach, Charles T.; Göring, Harald; Dhurandhar, Nikhil V.

2013-01-01

OBJECTIVE Ad36, a human adenovirus, increases adiposity but improves glycemic control in animal models. Similarly, natural Ad36 infection is cross-sectionally associated with greater adiposity and better glycemic control in humans. This study compared longitudinal observations in indices of adiposity (BMI and body fat percentage) and glycemic control (fasting glucose and insulin) in Ad36-infected versus uninfected adults. RESEARCH DESIGN AND METHODS Baseline sera from Hispanic men and women (n = 1,400) were screened post hoc for the presence of Ad36-specific antibodies. Indices of adiposity and glycemic control at baseline and at ∼10 years past the baseline were compared between seropositive and seronegative subjects, with adjustment for age and sex. In addition to age and sex, indices of glycemic control were adjusted for baseline BMI and were analyzed only for nondiabetic subjects. RESULTS Seropositive subjects (14.5%) had greater adiposity at baseline, compared with seronegative subjects. Longitudinally, seropositive subjects showed greater adiposity indices but lower fasting insulin levels. Subgroup analyses revealed that Ad36-seropositivity was associated with better baseline glycemic control and lower fasting insulin levels over time in the normal-weight group (BMI ≤25 kg/m2) and longitudinally, with greater adiposity in the overweight (BMI 25–30 kg/m2) and obese (BMI >30 kg/m2) men. Statistically, the differences between seropositive and seronegative individuals were modest in light of the multiple tests performed. CONCLUSIONS This study strengthens the plausibility that in humans, Ad36 increases adiposity and attenuates deterioration of glycemic control. Panoptically, the study raises the possibility that certain infections may modulate obesity or diabetes risk. A comprehensive understanding of these under-recognized factors is needed to effectively combat such metabolic disorders. PMID:23160725

Field-aligned currents' scale analysis performed with the Swarm constellation

NASA Astrophysics Data System (ADS)

Lühr, Hermann; Park, Jaeheung; Gjerloev, Jesper W.; Rauberg, Jan; Michaelis, Ingo; Merayo, Jose M. G.; Brauer, Peter

2015-01-01

We present a statistical study of the temporal- and spatial-scale characteristics of different field-aligned current (FAC) types derived with the Swarm satellite formation. We divide FACs into two classes: small-scale, up to some 10 km, which are carried predominantly by kinetic Alfvén waves, and large-scale FACs with sizes of more than 150 km. For determining temporal variability we consider measurements at the same point, the orbital crossovers near the poles, but at different times. From correlation analysis we obtain a persistent period of small-scale FACs of order 10 s, while large-scale FACs can be regarded stationary for more than 60 s. For the first time we investigate the longitudinal scales. Large-scale FACs are different on dayside and nightside. On the nightside the longitudinal extension is on average 4 times the latitudinal width, while on the dayside, particularly in the cusp region, latitudinal and longitudinal scales are comparable.

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

PubMed

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

2018-05-01

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

Impaired right ventricular contractile function in childhood obesity and its association with right and left ventricular changes: a cine DENSE cardiac magnetic resonance study.

PubMed

Jing, Linyuan; Pulenthiran, Arichanah; Nevius, Christopher D; Mejia-Spiegeler, Abba; Suever, Jonathan D; Wehner, Gregory J; Kirchner, H Lester; Haggerty, Christopher M; Fornwalt, Brandon K

2017-06-28

Pediatric obesity is a growing public health problem, which is associated with increased risk of cardiovascular disease and premature death. Left ventricular (LV) remodeling (increased myocardial mass and thickness) and contractile dysfunction (impaired longitudinal strain) have been documented in obese children, but little attention has been paid to the right ventricle (RV). We hypothesized that obese/overweight children would have evidence of RV remodeling and contractile dysfunction. One hundred and three children, ages 8-18 years, were prospectively recruited and underwent cardiovascular magnetic resonance (CMR), including both standard cine imaging and displacement encoding with stimulated echoes (DENSE) imaging, which allowed for quantification of RV geometry and function/mechanics. RV free wall longitudinal strain was quantified from the end-systolic four-chamber DENSE image. Linear regression was used to quantify correlations of RV strain with LV strain and measurements of body composition (adjusted for sex and height). Analysis of variance was used to study the relationship between RV strain and LV remodeling types (concentric remodeling, eccentric/concentric hypertrophy). The RV was sufficiently visualized with DENSE in 70 (68%) subjects, comprising 36 healthy weight (13.6 ± 2.7 years) and 34 (12.1 ± 2.9 years) obese/overweight children. Obese/overweight children had a 22% larger RV mass index (8.2 ± 0.9 vs 6.7 ± 1.1 g/m 2.7 , p < 0.001) compared to healthy controls. RV free wall longitudinal strain was impaired in obese/overweight children (-16 ± 4% vs -19 ± 5%, p = 0.02). Ten (14%) out of 70 children had LV concentric hypertrophy, and these children had the most impaired RV longitudinal strain compared to those with normal LV geometry (-13 ± 4% vs -19 ± 5%, p = 0.002). RV longitudinal strain was correlated with LV longitudinal strain (r = 0.34, p = 0.004), systolic blood pressure (r = 0.33, p = 0.006), as well as BMI z-score (r = 0.28, p = 0.02), waist (r = 0.31, p = 0.01), hip (r = 0.40, p = 0.004) and abdominal (r = 0.38, p = 0.002) circumference, height and sex adjusted. Obese/overweight children have evidence of RV remodeling (increased RV mass) and RV contractile dysfunction (impaired free wall longitudinal strain). Moreover, RV longitudinal strain correlates with LV longitudinal strain, and children with LV concentric hypertrophy show the most impaired RV function. These results suggest there may be a common mechanism underlying both remodeling and dysfunction of the left and right ventricles in obese/overweight children.

Nonlinear Association Between Cerebrospinal Fluid and Florbetapir F-18 β-Amyloid Measures Across the Spectrum of Alzheimer Disease.

PubMed

Toledo, Jon B; Bjerke, Maria; Da, Xiao; Landau, Susan M; Foster, Norman L; Jagust, William; Jack, Clifford; Weiner, Michael; Davatzikos, Christos; Shaw, Leslie M; Trojanowski, John Q

2015-05-01

Cerebrospinal fluid (CSF) and positron emission tomographic (PET) amyloid biomarkers have been proposed for the detection of Alzheimer disease (AD) pathology in living patients and for the tracking of longitudinal changes, but the relation between biomarkers needs further study. To determine the association between CSF and PET amyloid biomarkers (cross-sectional and longitudinal measures) and compare the cutoffs for these measures. Longitudinal clinical cohort study from 2005 to 2014 including 820 participants with at least 1 florbetapir F-18 (hereafter referred to as simply florbetapir)-PET scan and at least 1 CSF β-amyloid 1-42 (Aβ1-42) sample obtained within 30 days of each other (501 participants had a second PET scan after 2 years, including 150 participants with CSF Aβ1-42 measurements). Data were obtained from the Alzheimer's Disease Neuroimaging Initiative database. Four different PET scans processing pipelines from 2 different laboratories were compared. The PET cutoff values were established using a mixture-modeling approach, and different mathematical models were applied to define the association between CSF and PET amyloid measures. The values of the CSF Aβ1-42 samples and florbetapir-PET scans showed a nonlinear association (R2 = 0.48-0.66), with the strongest association for values in the middle range. The presence of a larger dynamic range of florbetapir-PET scan values in the higher range compared with the CSF Aβ1-42 plateau explained the differences in correlation with cognition (R2 = 0.36 and R2 = 0.25, respectively). The APOE genotype significantly modified the association between both biomarkers. The PET cutoff values derived from an unsupervised classifier converged with previous PET cutoff values and the established CSF Aβ1-42 cutoff levels. There was no association between longitudinal Aβ1-42 levels and standardized uptake value ratios during follow-up. The association between both biomarkers is limited to a middle range of values, is modified by the APOE genotype, and is absent for longitudinal changes; 4 different approaches in 2 different platforms converge on similar pathological Aβ cutoff levels; and different pipelines to process PET scans showed correlated but not identical results. Our findings suggest that both biomarkers measure different aspects of AD Aβ pathology.

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

ERIC Educational Resources Information Center

Chang, Mido

2012-01-01

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

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

PubMed

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

2016-06-01

Studies on longitudinal brain volume changes in patients with early-onset psychosis (EOP) are particularly valuable for understanding the neurobiological basis of brain abnormalities associated with psychosis. However, findings have not been consistent across studies in this population. We aimed to conduct a meta-analysis on progressive brain volume changes in children and adolescents with EOP. A systematic literature search of magnetic resonance imaging (MRI) studies comparing longitudinal brain volume changes in children and adolescents with EOP and healthy controls was conducted. The annualized rates of relative change in brain volume by region of interest (ROI) were used as raw data for the meta-analysis. The effect of age, sex, duration of illness, and specific diagnosis on volume change was also evaluated. Five original studies with 156 EOP patients (mean age at baseline MRI in the five studies ranged from 13.3 to 16.6years, 67.31% males) and 163 age- and sex-matched healthy controls, with a mean duration of follow-up of 2.46years (range 2.02-3.40), were included. Frontal gray matter (GM) was the only region in which significant differences in volume change over time were found between patients and controls (Hedges' g -0.435, 95% confidence interval (CI): -0.678 to -0.193, p<0.001). Younger age at baseline MRI was associated with greater loss of temporal GM volume over time in patients as compared with controls (p=0.005). Within patients, a diagnosis of schizophrenia was related to greater occipital GM volume loss over time (p=0.001). Compared with healthy individuals, EOP patients show greater progressive frontal GM loss over the first few years after illness onset. Age at baseline MRI and diagnosis of schizophrenia appear to be significant moderators of particular specific brain volume changes. Copyright © 2014 Elsevier B.V. All rights reserved.

The 2008 financial crisis: Changes in social capital and its association with psychological wellbeing in the United Kingdom - A panel study.

PubMed

Lindström, Martin; Giordano, Giuseppe N

2016-03-01

The global financial crisis of 2008 was described by the IMF as the worst recession since the Great Depression. This historic event provided the backdrop to this United Kingdom (UK) longitudinal study of changes in associations between social capital and psychological wellbeing. Past longitudinal studies have reported that the presence of social capital may buffer against adverse mental health outcomes. This study adds to existing literature by employing data from the British Household Panel Survey and tracking the same individuals (N = 11,743) pre- and immediately post-crisis (years 2007-09). With longitudinal, multilevel logistic regression modelling, we aimed to compare the buffering effects of individual-level social capital (generalised trust and social participation) against worse psychological wellbeing (GHQ-12) during and immediately after the 2008 financial crisis. After comparing the same individuals over time, results showed that stocks of social capital (generalised trust) were significantly depleted across the UK during the crisis, from 40% trusting others in 2007 to 32% in 2008. Despite this drop, the buffering effect of trust against worse psychological wellbeing was pronounced in 2008; those not trusting had an increased risk of worse psychological wellbeing in 2008 compared with the previous year in fully adjusted models (OR = 1.49, 95% CI (1.34-1.65). Levels of active participation increased across the timeframe of this study but were not associated with psychological health. From our empirical evidence, decision makers should be made aware of how events such as the crisis (and the measures taken to counter its effects) could negatively impact on a Nation's trust levels. Furthermore, past research implies that the positive effects of trust on psychological wellbeing evident in this study may only be short-term; therefore, decision makers should also prioritise policies that restore trust levels to improve the psychological wellbeing of the population. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Results of endocapsular phacofracture debulking of hard cataracts.

PubMed

Davison, James A

2015-01-01

To present a phacoemulsification technique for hard cataracts and compare postoperative results using two different ultrasonic tip motions during quadrant removal. A phacoemulsification technique which employs in situ fracture and endocapsular debulking for hard cataracts is presented. The prospective study included 56 consecutive cases of hard cataract (LOCS III NC [Lens Opacification Classification System III, nuclear color], average 4.26), which were operated using the Infiniti machine and the Partial Kelman tip. Longitudinal tip movement was used for sculpting for all cases which were randomized to receive longitudinal or torsional/interjected longitudinal (Intelligent Phaco [IP]) strategies for quadrant removal. Measurements included cumulative dissipated energy (CDE), 3 months postoperative surgically induced astigmatism (SIA), and corneal endothelial cell density (ECD) losses. No complications were recorded in any of the cases. Respective overall and longitudinal vs IP means were as follows: CDE, 51.6±15.6 and 55.7±15.5 vs 48.6±15.1; SIA, 0.36±0.2 D and 0.4±0.2 D vs 0.3±0.2 D; and mean ECD loss, 4.1%±10.8% and 5.9%±13.4% vs 2.7%±7.8%. The differences between longitudinal and IP were not significant for any of the three categories. The endocapsular phacofracture debulking technique is safe and effective for phacoemulsification of hard cataracts using longitudinal or torsional IP strategies for quadrant removal with the Infiniti machine and Partial Kelman tip.

Online versus offline spatiotemporal image correlation (STIC) M-mode for the evaluation of cardiac longitudinal annular displacement in fetal growth restriction.

PubMed

Tanis, Jozien C; Mohammed, Nuruddin; Bennasar, Mar; Martinez, Josep Maria; Bijnens, Bart; Crispi, Fatima; Gratacos, Eduard

2018-07-01

Our first aim was to compare online M-mode with offline spatiotemporal image correlation (STIC) M-mode for assessing longitudinal annular displacement (LAD) in growth-restricted fetuses (FGR). Our second aim was to compare LAD measures of FGR cases with controls. Prospective study including 40 FGR cases (defined estimated fetal weight and birth weight <10th centile) and 72 normally grown fetuses matched to cases by gestational age at scan. LAD was measured with online M-mode and offline STIC M-mode at the left and right ventricular free walls and septum in all fetuses. FGR cases had a significant decrease in LAD by STIC in all sites as compared to controls (e.g. right LAD in FGR mean 6.7 mm (SD 1.2) versus controls 7.2 mm (1.2), p = .033). There was a non-significant trend for lower values in FGR when using online M-mode (e.g. right LAD in FGR 6.9 mm (1.5) versus controls 7.4 mm (1.5), p = .084). STIC M-mode seems a better method than online M-mode for detecting subtle changes in myocardial motion. STIC presents more precise results and allows an ideal placement of the M-mode arrow. These results confirm previous data suggesting decreased longitudinal motion in FGR.

Replication of an association of variation in the FOXO3A gene with human longevity using both case–control and longitudinal data

PubMed Central

Soerensen, Mette; Dato, Serena; Christensen, Kaare; McGue, Matt; Stevnsner, Tinna; Bohr, Vilhelm A.; Christiansen, Lene

2010-01-01

Summary Genetic variation in FOXO3A has previously been associated with human longevity. Studies published so far have been case–control studies and hence vulnerable to bias introduced by cohort effects. In this study we extended the previous findings in the cohorts of oldest old Danes (the Danish 1905 cohort, N = 1089) and middle-aged Danes (N = 736), applying a longitudinal study design as well as the case–control study design. Fifteen SNPs were chosen in order to cover the known common variation in FOXO3A. Comparing SNP frequencies in the oldest old with middle-aged individuals, we found association (after correction for multiple testing) of eight SNPs; 4 (rs13217795, rs2764264, rs479744, and rs9400239) previously reported to be associated with longevity and four novel SNPs (rs12206094, rs13220810, rs7762395, and rs9486902 (corrected P-values 0.001–0.044). Moreover, we found association of the haplotypes TAC and CAC of rs9486902, rs10499051, and rs12206094 (corrected P-values: 0.01–0.03) with longevity. Finally, we here present data applying a longitudinal study design; when using follow-up survival data on the oldest old in a longitudinal analysis, we found no SNPs to remain significant after the correction for multiple testing (Bonferroni correction). Hence, our results support and extent the proposed role of FOXO3A as a candidate longevity gene for survival from younger ages to old age, yet not during old age. PMID:20849522

Reassessing the educational environment among undergraduate students in a chiropractic training institution: A study over time.

PubMed

Palmgren, Per J; Sundberg, Tobias; Laksov, Klara Bolander

2015-10-01

The aim of the study was twofold: (1) to compare the perceived educational environment at 2 points in time and (2) to longitudinally examine potential changes in perceptions of the educational environment over time. The validated Dundee Ready Educational Environment Measure (DREEM), a 50-item, self-administered Likert-type inventory, was used in this prospective study. Employing convenience sampling, undergraduate chiropractic students were investigated at 2 points in time: 2009 (n = 124) and 2012 (n = 127). An analysis of 2 matching samples was performed on 27% (n = 34) of the respondents in 2009. A total of 251 students (79%) completed the inventory, 83% (n = 124) in 2009 and 75% (n = 127) in 2012. The overall DREEM scores in both years were excellent: 156 (78%) and 153 (77%), respectively. The students' perceptions of teachers differed significantly between the 2 cohort years, decreasing from 77% to 73%. Three items received deprived scores: limited support for stressed students, authoritarian teachers, and an overemphasis on factual learning; the latter significantly decreased in 2012. In the longitudinal sample these items also displayed scores below the expected mean. Students viewed the educational environment as excellent both in 2009 and 2012. The perceptions of teachers declined with time; however, this could be attributed to teachers' new roles. Certain aspects of the educational environment factored prominently during the comparative points in time, as well as longitudinally, and these ought to be further investigated and addressed to provide an enhanced educational environment.

Longitudinal study of fingerprint recognition.

PubMed

Yoon, Soweon; Jain, Anil K

2015-07-14

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

Length Normalized Indices for Fat Mass and Fat-Free Mass in Preterm and Term Infants during the First Six Months of Life

PubMed Central

Goswami, Ipsita; Rochow, Niels; Fusch, Gerhard; Liu, Kai; Marrin, Michael L.; Heckmann, Matthias; Nelle, Mathias; Fusch, Christoph

2016-01-01

Objective: Postnatal tissue accretion in preterm infants differs from those in utero, affecting body composition (BC) and lifelong morbidity. Length normalized BC data allows infants with different body lengths to be compared and followed longitudinally. This study aims to analyze BC of preterm and term infants during the first six months of life. Methods: The BC data, measured using dual energy X-ray absorptiometry, of 389 preterm and 132 term infants from four longitudinal studies were combined. Fat-mass/length2 (FMI) and fat-free mass/length2 (FFMI) for postmenstrual age were calculated after reaching full enteral feeding, at term and two further time points up to six months corrected age. Results: Median FMI (preterm) increased from 0.4 kg/m2 at 30 weeks to 2.5, 4.3, and 4.8 kg/m2 compared to 1.7, 4.7, and 6 kg/m2 in term infants at 40, 52, and 64 weeks, respectively. Median FFMI (preterm) increased from 8.5 kg/m2 (30 weeks) to 11.4 kg/m2 (45 weeks) and remained constant thereafter, whereas term FFMI remained constant at 11 kg/m2 throughout the tested time points. Conclusion: The study provides a large dataset of length normalized BC indices. Followed longitudinally, term and preterm infants differ considerably during early infancy in the pattern of change in FMI and FFMI for age. PMID:27399768

Longitudinal study of fingerprint recognition

PubMed Central

Yoon, Soweon; Jain, Anil K.

2015-01-01

Human identification by fingerprints is based on the fundamental premise that ridge patterns from distinct fingers are different (uniqueness) and a fingerprint pattern does not change over time (persistence). Although the uniqueness of fingerprints has been investigated by developing statistical models to estimate the probability of error in comparing two random samples of fingerprints, the persistence of fingerprints has remained a general belief based on only a few case studies. In this study, fingerprint match (similarity) scores are analyzed by multilevel statistical models with covariates such as time interval between two fingerprints in comparison, subject’s age, and fingerprint image quality. Longitudinal fingerprint records of 15,597 subjects are sampled from an operational fingerprint database such that each individual has at least five 10-print records over a minimum time span of 5 y. In regard to the persistence of fingerprints, the longitudinal analysis on a single (right index) finger demonstrates that (i) genuine match scores tend to significantly decrease when time interval between two fingerprints in comparison increases, whereas the change in impostor match scores is negligible; and (ii) fingerprint recognition accuracy at operational settings, nevertheless, tends to be stable as the time interval increases up to 12 y, the maximum time span in the dataset. However, the uncertainty of temporal stability of fingerprint recognition accuracy becomes substantially large if either of the two fingerprints being compared is of poor quality. The conclusions drawn from 10-finger fusion analysis coincide with the conclusions from single-finger analysis. PMID:26124106

State variations in Medicaid enrollment and utilization of substance use services: Results from a National Longitudinal Study.

PubMed

Mojtabai, Ramin; Feder, Kenneth A; Kealhofer, Marc; Krawczyk, Noa; Storr, Carla; Tormohlen, Kayla N; Young, Andrea S; Olfson, Mark; Crum, Rosa M

2018-06-01

Medicaid enrollment varies considerably among states. This study examined the association of Medicaid enrollment with the use of substance health services in the longitudinal National Epidemiologic Survey on Alcohol and Related Conditions of 2001-2005. Instrumental variable methods were used to assess endogeneity of individual-level Medicaid enrollment using state-level data as instruments. Compared to the uninsured, Medicaid covered adults were more likely to use substance use disorder treatment services over the next three years. States that have opted to expand Medicaid enrollment under the Affordable Care Act will likely experience further increases in the use of these service over the coming years. Copyright © 2018 Elsevier Inc. All rights reserved.

Risky Sexual Behavior of Foreign and Native-born Women in Emerging Adulthood: The Long Reach of Mother-Daughter Relationships in Adolescence

PubMed Central

Samari, Goleen; Seltzer, Judith A.

2016-01-01

Parents’ influence on young adult sexual behavior receives little attention compared to influence on adolescent behavior. Yet effective parenting should have lasting effects. Even fewer studies examine parents’ influence on sexual behavior of both foreign and native-born young adults. Using the National Longitudinal Study of Adolescent to Adult Health (Add Health) Waves I (1994–95) and III (2001–02), we examine longitudinal associations among mother-daughter relationship quality and nativity during adolescence and young adults’ risky sexual behaviors of condom use at last intercourse, number of sexual partners, and STI diagnoses (N=4,460). Women, 18 to 26 years old, who had good mother-adolescent daughter relationships have fewer partners and STIs in the past year. Second generation women have worse mother-adolescent daughter relationships, compared to third generation. Relationship quality does not explain associations between nativity and risky behavior. Lasting associations between relationship quality and risk behaviors suggest that reproductive health interventions should enhance motheradolescent relationships. PMID:27712681

The Acquisition of Mathematics Pedagogical Content Knowledge in University Mathematics Education Courses: Results of a Mixed Methods Study on the Effectiveness of Teacher Education in Germany

ERIC Educational Resources Information Center

Buchholtz, Nils Frederik

2017-01-01

This paper reports on a longitudinal mixed methods evaluation study on the acquisition and development of mathematical pedagogical content knowledge (MPCK) of future teachers at several German universities. The study is a German supplementary study to the international comparative TEDS-M 2008 study. Besides the pedagogical content knowledge that…

Higher integrity of the motor and visual pathways in long-term video game players.

PubMed

Zhang, Yang; Du, Guijin; Yang, Yongxin; Qin, Wen; Li, Xiaodong; Zhang, Quan

2015-01-01

Long term video game players (VGPs) exhibit superior visual and motor skills compared with non-video game control subjects (NVGCs). However, the neural basis underlying the enhanced behavioral performance remains largely unknown. To clarify this issue, the present study compared the whiter matter integrity within the corticospinal tracts (CST), the superior longitudinal fasciculus (SLF), the inferior longitudinal fasciculus (ILF), and the inferior fronto-occipital fasciculus (IFOF) between the VGPs and the NVGCs using diffusion tensor imaging. Compared with the NVGCs, voxel-wise comparisons revealed significantly higher fractional anisotropy (FA) values in some regions within the left CST, left SLF, bilateral ILF, and IFOF in VGPs. Furthermore, higher FA values in the left CST at the level of cerebral peduncle predicted a faster response in visual attention tasks. These results suggest that higher white matter integrity in the motor and higher-tier visual pathways is associated with long-term video game playing, which may contribute to the understanding on how video game play influences motor and visual performance.

Higher integrity of the motor and visual pathways in long-term video game players

PubMed Central

Du, Guijin; Yang, Yongxin; Qin, Wen; Li, Xiaodong; Zhang, Quan

2015-01-01

Long term video game players (VGPs) exhibit superior visual and motor skills compared with non-video game control subjects (NVGCs). However, the neural basis underlying the enhanced behavioral performance remains largely unknown. To clarify this issue, the present study compared the whiter matter integrity within the corticospinal tracts (CST), the superior longitudinal fasciculus (SLF), the inferior longitudinal fasciculus (ILF), and the inferior fronto-occipital fasciculus (IFOF) between the VGPs and the NVGCs using diffusion tensor imaging. Compared with the NVGCs, voxel-wise comparisons revealed significantly higher fractional anisotropy (FA) values in some regions within the left CST, left SLF, bilateral ILF, and IFOF in VGPs. Furthermore, higher FA values in the left CST at the level of cerebral peduncle predicted a faster response in visual attention tasks. These results suggest that higher white matter integrity in the motor and higher-tier visual pathways is associated with long-term video game playing, which may contribute to the understanding on how video game play influences motor and visual performance. PMID:25805981

Right-sizing statistical models for longitudinal data.

PubMed

Wood, Phillip K; Steinley, Douglas; Jackson, Kristina M

2015-12-01

Arguments are proposed that researchers using longitudinal data should consider more and less complex statistical model alternatives to their initially chosen techniques in an effort to "right-size" the model to the data at hand. Such model comparisons may alert researchers who use poorly fitting, overly parsimonious models to more complex, better-fitting alternatives and, alternatively, may identify more parsimonious alternatives to overly complex (and perhaps empirically underidentified and/or less powerful) statistical models. A general framework is proposed for considering (often nested) relationships between a variety of psychometric and growth curve models. A 3-step approach is proposed in which models are evaluated based on the number and patterning of variance components prior to selection of better-fitting growth models that explain both mean and variation-covariation patterns. The orthogonal free curve slope intercept (FCSI) growth model is considered a general model that includes, as special cases, many models, including the factor mean (FM) model (McArdle & Epstein, 1987), McDonald's (1967) linearly constrained factor model, hierarchical linear models (HLMs), repeated-measures multivariate analysis of variance (MANOVA), and the linear slope intercept (linearSI) growth model. The FCSI model, in turn, is nested within the Tuckerized factor model. The approach is illustrated by comparing alternative models in a longitudinal study of children's vocabulary and by comparing several candidate parametric growth and chronometric models in a Monte Carlo study. (c) 2015 APA, all rights reserved).

Longitudinal association between cognitive performance and obsessive-compulsive symptoms in patients with psychosis and unaffected siblings.

PubMed

Schirmbeck, F; Swets, M; Meijer, C J; Zink, M; de Haan, L

2016-05-01

Obsessive-compulsive symptoms (OCS) frequently occur in psychotic disorders. Cross-sectional associations between OCS and cognitive impairment have led to different causal explanations. Whereas one assumes that higher cognitive impairment reflects a risk factor for psychotic patients to develop OCS, another suggests that deficits reflect a consequence of OCS. This study investigated the longitudinal interrelation between OCS and cognitive functioning. Baseline and follow-up data from 622 patients and 670 un-affected siblings from the 'Genetic Risk and Outcome in Psychosis' study were analyzed. Participants were allocated to groups according to the presence or absence of OCS at assessments and compared on several cognitive domains. Cross-sectional comparisons revealed no group differences in cognitive performance. Longitudinal analyses comparing the groups with changes in OCS revealed one significant group effect with more problems in set-shifting abilities in patient who reported OCS development at follow-up. Significant time and interaction effects were mainly due to improvement in immediate verbal recall and digit-symbol coding in patients and siblings who reported remission of OCS. Although insight into causality needs further exploration, our results do not confirm the hypothesis of pre-existing cognitive risk constellations. Findings suggest that remission of comorbid OCS results in improved immediate verbal recall and processing speed. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Longitudinal change in CSF biomarkers in autosomal-dominant Alzheimer disease

PubMed Central

Fagan, Anne M.; Xiong, Chengjie; Jasielec, Mateusz S.; Bateman, Randall J.; Goate, Alison M.; Benzinger, Tammie L.S.; Ghetti, Bernardino; Martins, Ralph N.; Masters, Colin L.; Mayeux, Richard; Ringman, John M.; Rossor, Martin N.; Salloway, Stephen; Schofield, Peter R.; Sperling, Reisa A.; Marcus, Daniel; Cairns, Nigel J.; Buckles, Virginia D.; Ladenson, Jack H.; Morris, John C.; Holtzman, David M.

2014-01-01

Clinicopathologic evidence suggests the pathology of Alzheimer disease (AD) begins many years prior to cognitive symptoms. Biomarkers are required to identify affected individuals during this asymptomatic (“pre-clinical”) stage to permit intervention with potential disease-modifying therapies designed to preserve normal brain function. Studies of families with autosomal-dominant AD (ADAD) mutations provide a unique and powerful means to investigate AD biomarker changes during the asymptomatic period. In this biomarker study comparing cerebrospinal fluid (CSF), plasma and in vivo amyloid imaging, cross-sectional data obtained at baseline in individuals from ADAD families enrolled in the Dominantly Inherited Alzheimer Network (DIAN) demonstrate reduced concentrations of CSF amyloid-β1-42 (Aβ1–42) associated with the presence of β-amyloid plaques, and elevated concentrations of CSF tau, ptau181 and VILIP-1, markers of neurofibrillary tangles and/or neuronal injury/death, in asymptomatic mutation carriers 10-20 years prior to their estimated age at symptom onset (EAO), and prior to detection of cognitive deficits. When compared longitudinally, however, the concentrations of CSF biomarkers of neuronal injury/death within-individuals decrease after their EAO, suggesting a slowing of acute neurodegenerative processes with symptomatic disease progression. These results emphasize the importance of longitudinal, within-person assessment when modeling biomarker trajectories across the course of the disease. If corroborated, this pattern may influence the definition of a positive neurodegenerative biomarker outcome in clinical trials. PMID:24598588

The persistence of personal and social themes in context: Long- and short-term studies of students' scientific ideas

NASA Astrophysics Data System (ADS)

Helldén, Gustav F.; Solomon, Joan

2004-11-01

In this paper we will examine the persistence of misconceptions. We used data from a longitudinal study of personal ideas in 24 students' thinking about ecological processes. The results show students often speaking about personal experiences dating from an early age, to which they had also referred in similar interviews conducted years before. These data are compared with results from a different study of middle school physics students' thinking about energy and steam engines. After the new learning had been successfull completed and assessed, old ideas returned. These findings are used to set up a theoretical basis for understanding the longitudinal results. Findings from memory studies are shown to explicate the long-term effects of the passage of time and prompts for the recall of scientific concepts.

Health-promoting factors in medical students and students of science, technology, engineering, and mathematics: design and baseline results of a comparative longitudinal study

PubMed Central

2014-01-01

Background The negative impact of medical school on students' general and mental health has often been reported. Compared to students of other subjects, or employed peers, medical students face an increased risk of developing depression, anxiety and burnout. While pathogenetic factors have been studied extensively, less is known about health-promoting factors for medical students' health. This longitudinal study aims to identify predictors for maintaining good general and mental health during medical education. We report here the design of the study and its baseline results. Methods We initiated a prospective longitudinal cohort study at the University of Lübeck, Germany. Two consecutive classes of students, entering the university in 2011 and 2012, were recruited. Participants will be assessed annually for the duration of their course. We use validated psychometric instruments covering health outcomes (general and mental health) and personality traits, as well as self-developed, pre-tested items covering leisure activities and sociodemographic data. Results At baseline, compared to students of STEM (science, technology, engineering, and mathematics) subjects (n = 531; 60.8% response rate), a larger proportion of medical students (n = 350; 93.0% response rate) showed good general health (90.9% vs. 79.7%) and a similar proportion was in good mental health (88.3% vs. 86.3%). Medical students scored significantly higher in the personality traits of extraversion, conscientiousness, openness to experience and agreeableness. Neuroticism proved to be a statistically significant negative predictor for mental health in the logistic regression analyses. Satisfaction with life as a dimension of study-related behaviour and experience predicted general health at baseline. Physical activity was a statistically significant predictor for general health in medical students. Conclusions Baseline data revealed that medical students reported better general and similar mental health compared to STEM students. The annual follow-up questionnaires, combined with qualitative approaches, should clarify wether these differences reflect a higher resilience, a tendency to neglect personal health problems - as has been described for physicians - before entering medical school, or both. The final results may aid decision-makers in developing health-promotion programmes for medical students. PMID:24996637

Health-promoting factors in medical students and students of science, technology, engineering, and mathematics: design and baseline results of a comparative longitudinal study.

PubMed

Kötter, Thomas; Tautphäus, Yannick; Scherer, Martin; Voltmer, Edgar

2014-07-04

The negative impact of medical school on students' general and mental health has often been reported. Compared to students of other subjects, or employed peers, medical students face an increased risk of developing depression, anxiety and burnout. While pathogenetic factors have been studied extensively, less is known about health-promoting factors for medical students' health. This longitudinal study aims to identify predictors for maintaining good general and mental health during medical education. We report here the design of the study and its baseline results. We initiated a prospective longitudinal cohort study at the University of Lübeck, Germany. Two consecutive classes of students, entering the university in 2011 and 2012, were recruited. Participants will be assessed annually for the duration of their course. We use validated psychometric instruments covering health outcomes (general and mental health) and personality traits, as well as self-developed, pre-tested items covering leisure activities and sociodemographic data. At baseline, compared to students of STEM (science, technology, engineering, and mathematics) subjects (n = 531; 60.8% response rate), a larger proportion of medical students (n = 350; 93.0% response rate) showed good general health (90.9% vs. 79.7%) and a similar proportion was in good mental health (88.3% vs. 86.3%). Medical students scored significantly higher in the personality traits of extraversion, conscientiousness, openness to experience and agreeableness. Neuroticism proved to be a statistically significant negative predictor for mental health in the logistic regression analyses. Satisfaction with life as a dimension of study-related behaviour and experience predicted general health at baseline. Physical activity was a statistically significant predictor for general health in medical students. Baseline data revealed that medical students reported better general and similar mental health compared to STEM students. The annual follow-up questionnaires, combined with qualitative approaches, should clarify wether these differences reflect a higher resilience, a tendency to neglect personal health problems - as has been described for physicians - before entering medical school, or both. The final results may aid decision-makers in developing health-promotion programmes for medical students.

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

PubMed

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

2018-01-01

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

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

PubMed Central

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

2018-01-01

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

The importance of the orientation of the electrode plates in recording the external anal sphincter EMG by non-invasive anal plug electrodes.

PubMed

Binnie, N R; Kawimbe, B M; Papachrysostomou, M; Clare, N; Smith, A N

1991-02-01

Two non-invasive anal plug electrodes of similar size have been compared, one with the electrode plates orientated circularly in the anal canal and the other with the plates in the long axis of the anal canal. There was a significant increase in the amplitude in the EMG signals recorded at rest and during squeeze from the external anal sphincter with a longitudinally placed electrode in 117 patients. Inappropriate contraction of the external anal sphincter when straining at stool was more readily detected using the longitudinal electrode in 52 patients investigated for intractable constipation. The longitudinal electrode detected the amplitude of the response to the elicitation of a pudeno-anal reflex more readily than the circular electrode. When in 12 of the 117 the pudeno-anal reflex EMG signal was either absent or not detected with the circumferential plug electrode, the longitudinal electrode detected the presence of a low amplitude response in 11 of these. When the non-invasive longitudinal electrode was compared to invasive fine wire stainless steel electrodes, a correlation was found for external anal sphincter resting EMG (r = 0.99, p less than 0.01), voluntary squeeze EMG (r = 0.99, p less than 0.001) and strain EMG (r = 0.91, p less than 0.01). The longitudinal anal plug electrode thus facilitates surface acquisition of EMG activity.

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

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-02

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

A Study of the Factors Associated with Risk for Development of Pressure Ulcers: A Longitudinal Analysis.

PubMed

Thomas, Elizebeth; Vinodkumar, Sudhaya; Mathew, Silvia; Setia, Maninder Singh

2015-01-01

Pressure ulcers (PUs) are prevalent in hospitalized patients; they may cause clinical, psychological, and economic problems in these patients. Previous studies are cross-sectional, have used pooled data, or cox-regression models to assess the risk for developing PU. However, PU risk scores change over time and models that account for time varying variables are useful for cohort analysis of data. The present longitudinal study was conducted to compare the risk of PU between surgical and nonsurgical patients, and to evaluate the factors associated with the development of these ulcers over a period of time. We evaluated 290 hospitalized patients over a 4 months period. The main outcomes for our analysis were: (1) Score on the pressure risk assessment scale; and (2) the proportion of individuals who were at severe risk for developing PUs. We used random effects models for longitudinal analysis of the data. The mean PU score was significantly higher in the nonsurgical patients compared with surgical patients at baseline (15.23 [3.86] vs. 9.33 [4.57]; P < 0.01). About 7% of the total patients had a score of >20 at baseline and were considered as being at high-risk for PU; the proportion was significantly higher among the nonsurgical patients compared with the surgical patients (14% vs. 4%, P = 0.003). In the adjusted models, there was no difference for severe risk for PU between surgical and nonsurgical patients (odds ratios [ORs]: 0.37, 95% confidence interval [CI]: 0.01-12.80). An additional day in the ward was associated with a significantly higher likelihood of being at high-risk for PU (OR: 1.47, 95% CI: 1.16-1.86). There were no significant differences between patients who were admitted for surgery compared with those who were not. An additional day in the ward, however, is important for developing a high-risk score for PU on the monitoring scale, and these patients require active interventions.

Evaluation of Right Ventricular Myocardial Mechanics Using Velocity Vector Imaging of Cardiac MRI Cine Images in Transposition of the Great Arteries Following Atrial and Arterial Switch Operations.

PubMed

Thattaliyath, Bijoy D; Forsha, Daniel E; Stewart, Chad; Barker, Piers C A; Campbell, Michael J

2015-01-01

The aim of the study was to determine right and left ventricle deformation parameters in patients with transposition of the great arteries who had undergone atrial or arterial switch procedures. Patients with transposition are born with a systemic right ventricle. Historically, the atrial switch operation, in which the right ventricle remains the systemic ventricle, was performed. These patients have increased rates of morbidity and mortality. We used cardiac MRI with Velocity Vector Imaging analysis to characterize and compare ventricular myocardial deformation in patients who had an atrial switch or arterial switch operation. Patients with a history of these procedures, who had a clinically ordered cardiac MRI were included in the study. Consecutive 20 patients (75% male, 28.7 ± 1.8 years) who underwent atrial switch operation and 20 patients (60% male, 17.7 ± 1.9 years) who underwent arterial switch operation were included in the study. Four chamber and short-axis cine images were used to determine longitudinal and circumferential strain and strain rate using Vector Velocity Imaging software. Compared with the arterial switch group, the atrial switch group had decreased right ventricular ejection fraction and increased end-diastolic and end-systolic volumes, and no difference in left ventricular ejection fraction and volumes. The atrial switch group had decreased longitudinal and circumferential strain and strain rate. When compared with normal controls multiple strain parameters in the atrial switch group were reduced. Myocardial deformation analysis of transposition patients reveals a reduction of right ventricular function and decreased longitudinal and circumferential strain parameters in patients with an atrial switch operation compared with those with arterial switch operation. A better understanding of the mechanisms of right ventricle failure in transposition of great arteries may lead to improved therapies and adaptation. © 2015 Wiley Periodicals, Inc.

Longitudinal Analysis of Superficial Midfacial Fat Volumes Over a 10-Year Period.

PubMed

Tower, Jacob; Seifert, Kimberly; Paskhover, Boris

2018-04-11

Volumetric changes to facial fat that occur with aging remain poorly understood. The aim of this study was to evaluate for longitudinal changes to midfacial fat volumes in a group of individuals. We conducted a retrospective longitudinal study of adult subjects who underwent multiple facial computed tomographic (CT) scans timed at least 8 years apart. Subjects who underwent facial surgery or suffered facial trauma were excluded. Facial CT scans were analyzed, and superficial cheek fat volumes were measured and compared to track changes that occurred with aging. Fourteen subjects were included in our analysis of facial aging (5 male, 9 female; mean initial age 50.9 years; mean final age 60.4 years). In the right superficial cheek there was an increase in mean (SD) superficial fat volume from 10.33 (2.01) to 10.50 (1.80) cc, which was not statistically significant (P = 0.75). Similar results were observed in the left cheek. There were no statistically significant longitudinal changes to caudal, middle, or cephalad subdivisions of bilateral superficial cheek fat. A simple linear regression was performed to predict superficial cheek fat pad volume based on age which did not reach statistical significance (P = 0.31), with an R 2 of 0.039. This study is the first to quantitatively assess for longitudinal changes to midfacial fat in a group of individuals. Superficial cheek fat remained stable as subjects aged from approximately 50 to 60 years old, with no change in total volume or redistribution within a radiographically defined compartment. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

EUROSPINE 2016 FULL PAPER AWARD: Wire cerclage can restore the stability of the thoracic spine after median sternotomy: an in vitro study with entire rib cage specimens.

PubMed

Liebsch, Christian; Graf, Nicolas; Wilke, Hans-Joachim

2017-05-01

The influence of the anterior rib cage on the stability of the human thoracic spine is not completely known. One of the most common surgical interventions on the anterior rib cage is the longitudinal median sternotomy and its fixation by wire cerclage. Therefore, the purpose of this in vitro study was to examine, if wire cerclage can restore the stability of the human thoracic spine after longitudinal median sternotomy. Six fresh frozen human thoracic spine specimens (C7-L1, 56 years in average, range 50-65), including the intact rib cage without intercostal muscles, were tested in a spinal loading simulator and monitored with an optical motion tracking system. While applying 2 Nm pure moment in flexion/extension (FE), lateral bending (LB), and axial rotation (AR), the range of motion (ROM) and neutral zone (NZ) of the functional spinal units of the thoracic spine (T1-T12) were studied (1) in intact condition, (2) after longitudinal median sternotomy, and (3) after sternal closure using wire cerclage. The longitudinal median sternotomy caused a significant increase of the thoracic spine ROM relative to the intact condition (FE: 12° ± 5°, LB: 18° ± 5°, AR: 25° ± 10°) in FE (+12 %) and AR (+22 %). As a result, the sagittal cut faces of the sternum slipped apart visibly. Wire cerclage fixation resulted in a significant decrease of the ROM in AR (-12 %) relative to condition after sternotomy. ROM increased relative to the intact condition, in AR even significantly (+8 %). The NZ showed a proportional behavior compared to the ROM in all loading planes, but it was distinctly higher in FE (72 %) and in LB (82 %) compared to the ROM than in AR (12 %). In this in vitro study, the longitudinal median sternotomy resulted in a destabilization of the thoracic spine and relative motion of the sternal cut faces, which could be rectified by fixation with wire cerclage. However, the stability of the intact condition could not be reached. Nevertheless, a fixation of the sternum should be considered clinically to avoid instability of the spine and sternal pseudarthrosis.

The New York City Infant Day Care Study Design.

ERIC Educational Resources Information Center

Rosenbluth, Lucille

This paper provides a brief introduction to the New York City Infant Day Care Study, a 5-year, longitudinal study in which children in three different child rearing environments are compared: (1) infants in group day care, (2) infants in family day care, and (3) infants reared at home. Data are being collected on three major aspects of child…

Environmental Literacy of Pre-Service Teachers in Israel: A Comparison between Students at the Onset and End of Their Studies

ERIC Educational Resources Information Center

Yavetz, Bela; Goldman, Daphne; Pe'er, Sara

2009-01-01

The adequate preparation of teacher education students in environmental education is a prerequisite for their future ability to design and implement effective environmental education. This longitudinal study compared the environmental literacy of 214 students at the onset and towards the end of their studies, in three academic colleges of…

"PCI Reading Program": The Final Report of a Three Year Experimental Study in Brevard Public Schools and Miami-Dade County Public Schools. Research Report

ERIC Educational Resources Information Center

Toby, Megan; Jaciw, Andrew; Ma, Boya; Lipton, Akiko

2011-01-01

PCI Education conducted a three-year longitudinal study to determine the comparative effectiveness of the "PCI Reading Program" ("PCI") for students with severe disabilities as implemented in Florida's Brevard Public Schools and Miami-Dade County Public Schools. The primary question addressed by the study is whether students…

Aeroelastic Sizing for High-Speed Research (HSR) Longitudinal Control Alternatives Project (LCAP)

NASA Technical Reports Server (NTRS)

Walsh, Joanne L.; Dunn, H. J.; Stroud, W. Jefferson; Barthelemy, J.-F.; Weston, Robert P.; Martin, Carl J.; Bennett, Robert M.

2005-01-01

The Longitudinal Control Alternatives Project (LCAP) compared three high-speed civil transport configurations to determine potential advantages of the three associated longitudinal control concepts. The three aircraft configurations included a conventional configuration with a layout having a horizontal aft tail, a configuration with a forward canard in addition to a horizontal aft tail, and a configuration with only a forward canard. The three configurations were aeroelastically sized and were compared on the basis of operational empty weight (OEW) and longitudinal control characteristics. The sized structure consisted of composite honeycomb sandwich panels on both the wing and the fuselage. Design variables were the core depth of the sandwich and the thicknesses of the composite material which made up the face sheets of the sandwich. Each configuration was sized for minimum structural weight under linear and nonlinear aeroelastic loads subject to strain, buckling, ply-mixture, and subsonic and supersonic flutter constraints. This report describes the methods that were used and the results that were generated for the aeroelastic sizing of the three configurations.

Perceived somatic and affective barriers for self-efficacy and physical activity.

PubMed

Warner, Lisa M; Wolff, Julia K; Spuling, Svenja M; Wurm, Susanne

2017-05-01

According to Bandura's social-cognitive theory, perceptions of somatic and affective barriers are sources of self-efficacy. This longitudinal study compares general indicators of health barriers with measures of perceived somatic and affective barriers to predict self-efficacy and accelerometer-assessed physical activity in a subsample of n = 153 (selected at random from N = 310) community-dwelling German older adults. Perceived somatic and affective barriers longitudinally predicted physical activity mediated by self-efficacy, whereas general health barriers did not. Perceived health barriers to physical activity might be more important than more objective health barriers for older adults' physical activity levels.

A modulation technique for the measurement of the DC longitudinal Faraday effect

NASA Astrophysics Data System (ADS)

Hunte, Carlos

2018-03-01

A modulation of light technique, using a lock-in amplifier, is described and tested to investigate the longitudinal Faraday effect in isotropic media. The Faraday rotation is measured directly from the lock-in amplifier. The Verdet constant and dispersion of lead-silica SF-59 Schott glass, at room temperature of 25 °C, were determined for varying wavelengths and expressions for their wavelength dependence were determined. The Verdet constant of water is also investigated. The results compare extremely well with other studies. The technique is suited to measure very small Verdet constants and can be easily conducted in an upper-level undergraduate laboratory.

Estimation of Covariance Matrix on Bi-Response Longitudinal Data Analysis with Penalized Spline Regression

NASA Astrophysics Data System (ADS)

Islamiyati, A.; Fatmawati; Chamidah, N.

2018-03-01

The correlation assumption of the longitudinal data with bi-response occurs on the measurement between the subjects of observation and the response. It causes the auto-correlation of error, and this can be overcome by using a covariance matrix. In this article, we estimate the covariance matrix based on the penalized spline regression model. Penalized spline involves knot points and smoothing parameters simultaneously in controlling the smoothness of the curve. Based on our simulation study, the estimated regression model of the weighted penalized spline with covariance matrix gives a smaller error value compared to the error of the model without covariance matrix.

Tailored Panel Management: A Theory-Based Approach to Building and Maintaining Participant Commitment to a Longitudinal Study.

PubMed

Estrada, Mica; Woodcock, Anna; Schultz, P Wesley

2014-02-01

Many psychological processes unfold over time, necessitating longitudinal research designs. Longitudinal research poses a host of methodological challenges, foremost of which is participant attrition. Building on Dillman's work, we provide a review of how social influence and relationship research informs retention strategies in longitudinal studies. Objective: We introduce the tailored panel management (TPM) approach, which is designed to establish communal norms that increase commitment to a longitudinal study, and this commitment, in turn, increases response rates and buffers against attrition. Specifically, we discuss practices regarding compensation, communication, consistency, and credibility that increase longer term commitment to panel participation. Research design: Throughout the article, we describe how TPM is being used in a national longitudinal study of undergraduate minority science students. TheScienceStudy is a continuing panel, which has 12 waves of data collected across 6 academic years, with response rates ranging from 70% to 92%. Although more than 90% of participants have either left or graduated from their undergraduate degree program, this highly mobile group of people remains engaged in the study. TheScienceStudy has usable longitudinal data from 96% of the original panel. Conclusion: This article combines social psychological theory, current best practice, and a detailed case study to illustrate the TPM approach to longitudinal data collection. The approach provides guidance for other longitudinal researchers, and advocates for empirical research into longitudinal research methodologies. © The Author(s) 2014.

Brachial artery vasomotion and transducer pressure effect on measurements by active contour segmentation on ultrasound

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

Cary, Theodore W.; Sultan, Laith R.; Sehgal, Chandra M., E-mail: sehgalc@uphs.upenn.edu

Purpose: To use feed-forward active contours (snakes) to track and measure brachial artery vasomotion on ultrasound images recorded in both transverse and longitudinal views; and to compare the algorithm's performance in each view. Methods: Longitudinal and transverse view ultrasound image sequences of 45 brachial arteries were segmented by feed-forward active contour (FFAC). The segmented regions were used to measure vasomotion artery diameter, cross-sectional area, and distention both as peak-to-peak diameter and as area. ECG waveforms were also simultaneously extracted frame-by-frame by thresholding a running finite-difference image between consecutive images. The arterial and ECG waveforms were compared as they traced eachmore » phase of the cardiac cycle. Results: FFAC successfully segmented arteries in longitudinal and transverse views in all 45 cases. The automated analysis took significantly less time than manual tracing, but produced superior, well-behaved arterial waveforms. Automated arterial measurements also had lower interobserver variability as measured by correlation, difference in mean values, and coefficient of variation. Although FFAC successfully segmented both the longitudinal and transverse images, transverse measurements were less variable. The cross-sectional area computed from the longitudinal images was 27% lower than the area measured from transverse images, possibly due to the compression of the artery along the image depth by transducer pressure. Conclusions: FFAC is a robust and sensitive vasomotion segmentation algorithm in both transverse and longitudinal views. Transverse imaging may offer advantages over longitudinal imaging: transverse measurements are more consistent, possibly because the method is less sensitive to variations in transducer pressure during imaging.« less

Brachial artery vasomotion and transducer pressure effect on measurements by active contour segmentation on ultrasound.

PubMed

Cary, Theodore W; Reamer, Courtney B; Sultan, Laith R; Mohler, Emile R; Sehgal, Chandra M

2014-02-01

To use feed-forward active contours (snakes) to track and measure brachial artery vasomotion on ultrasound images recorded in both transverse and longitudinal views; and to compare the algorithm's performance in each view. Longitudinal and transverse view ultrasound image sequences of 45 brachial arteries were segmented by feed-forward active contour (FFAC). The segmented regions were used to measure vasomotion artery diameter, cross-sectional area, and distention both as peak-to-peak diameter and as area. ECG waveforms were also simultaneously extracted frame-by-frame by thresholding a running finite-difference image between consecutive images. The arterial and ECG waveforms were compared as they traced each phase of the cardiac cycle. FFAC successfully segmented arteries in longitudinal and transverse views in all 45 cases. The automated analysis took significantly less time than manual tracing, but produced superior, well-behaved arterial waveforms. Automated arterial measurements also had lower interobserver variability as measured by correlation, difference in mean values, and coefficient of variation. Although FFAC successfully segmented both the longitudinal and transverse images, transverse measurements were less variable. The cross-sectional area computed from the longitudinal images was 27% lower than the area measured from transverse images, possibly due to the compression of the artery along the image depth by transducer pressure. FFAC is a robust and sensitive vasomotion segmentation algorithm in both transverse and longitudinal views. Transverse imaging may offer advantages over longitudinal imaging: transverse measurements are more consistent, possibly because the method is less sensitive to variations in transducer pressure during imaging.

Brachial artery vasomotion and transducer pressure effect on measurements by active contour segmentation on ultrasound

PubMed Central

Cary, Theodore W.; Reamer, Courtney B.; Sultan, Laith R.; Mohler, Emile R.; Sehgal, Chandra M.

2014-01-01

Purpose: To use feed-forward active contours (snakes) to track and measure brachial artery vasomotion on ultrasound images recorded in both transverse and longitudinal views; and to compare the algorithm's performance in each view. Methods: Longitudinal and transverse view ultrasound image sequences of 45 brachial arteries were segmented by feed-forward active contour (FFAC). The segmented regions were used to measure vasomotion artery diameter, cross-sectional area, and distention both as peak-to-peak diameter and as area. ECG waveforms were also simultaneously extracted frame-by-frame by thresholding a running finite-difference image between consecutive images. The arterial and ECG waveforms were compared as they traced each phase of the cardiac cycle. Results: FFAC successfully segmented arteries in longitudinal and transverse views in all 45 cases. The automated analysis took significantly less time than manual tracing, but produced superior, well-behaved arterial waveforms. Automated arterial measurements also had lower interobserver variability as measured by correlation, difference in mean values, and coefficient of variation. Although FFAC successfully segmented both the longitudinal and transverse images, transverse measurements were less variable. The cross-sectional area computed from the longitudinal images was 27% lower than the area measured from transverse images, possibly due to the compression of the artery along the image depth by transducer pressure. Conclusions: FFAC is a robust and sensitive vasomotion segmentation algorithm in both transverse and longitudinal views. Transverse imaging may offer advantages over longitudinal imaging: transverse measurements are more consistent, possibly because the method is less sensitive to variations in transducer pressure during imaging. PMID:24506648

An integrated draft gear model with the consideration of wagon body structural characteristics

NASA Astrophysics Data System (ADS)

Chang, Gao; Liangliang, Yang; Weihua, Ma; Min, Zhang; Shihui, Luo

2018-03-01

With the increase of railway wagon axle load and the growth of marshalling quantity, the problem caused by impact and vibration of vehicles is increasingly serious, which leads to the damage of vehicle structures and the components. In order to improve the reliability of longitudinal connection model for vehicle impact tests, a new railway wagon longitudinal connection model was developed to simulate and analyse vehicle impact tests. The new model is based on characteristics of longitudinal force transmission for vehicles and parts. In this model, carbodies and bogies were simplified to a particle system that can vibrate in the longitudinal direction, which corresponded to a stiffness-damping vibration system. The model consists of three sub-models, that is, coupler and draft gear sub-model, centre plate sub-model and carbody structure sub-model. Compared with conventional draft gear models, the new model was proposed with geometrical and mechanical relations of friction draft gears considered and with behaviours of sticking, sliding and impact between centre plate and centre bowl added. Besides, virtual springs between discrete carbodies were built to describe the structural deformation of carbody. A computation program for longitudinal dynamics based on vehicle impact tests was accomplished to simulate. Comparisons and analyses regarding the train dynamics outputs and vehicle impact tests were conducted. Simulation results indicate that the new wagon longitudinal connection model can provide a practical application environment for wagons, and the outputs of vehicle impact tests agree with those of field tests. The new model can also be used to study on longitudinal vibrations of different vehicles, of carbody and bogie, and of carbody itself.

Longitudinal Cognitive Trajectories of Women Veterans from the Women’s Health Initiative Memory Study

PubMed Central

Padula, Claudia B.; Weitlauf, Julie C.; Rosen, Allyson C.; Reiber, Gayle; Cochrane, Barbara B.; Naughton, Michelle J.; Li, Wenjun; Rissling, Michelle; Yaffe, Kristine; Hunt, Julie R.; Stefanick, Marcia L.; Goldstein, Mary K.; Espeland, Mark A.

2016-01-01

Purpose of the Study: A comparison of longitudinal global cognitive functioning in women Veteran and non-Veteran participants in the Women’s Health Initiative (WHI). Design and Methods: We studied 7,330 women aged 65–79 at baseline who participated in the WHI Hormone Therapy Trial and its ancillary Memory Study (WHIMS). Global cognitive functioning (Modified Mini-Mental State Examination [3MSE]) in Veterans (n = 279) and non-Veterans (n = 7,051) was compared at baseline and annually for 8 years using generalized linear modeling methods. Results: Compared with non-Veterans, Veteran women were older, more likely to be Caucasian, unmarried, and had higher rates of educational and occupational attainment. Results of unadjusted baseline analyses suggest 3MSE scores were similar between groups. Longitudinal analyses, adjusted for age, education, ethnicity, and WHI trial assignment revealed differences in the rate of cognitive decline between groups over time, such that scores decreased more in Veterans relative to non-Veterans. This relative difference was more pronounced among Veterans who were older, had higher educational/occupational attainment and greater baseline prevalence of cardiovascular risk factors (e.g., smoking) and cardiovascular disease (e.g., angina, stroke). Implications: Veteran status was associated with higher prevalence of protective factors that may have helped initially preserve cognitive functioning. However, findings ultimately revealed more pronounced cognitive decline among Veteran relative to non-Veteran participants, likely suggesting the presence of risks that may impact neuropathology and the effects of which were initially masked by Veterans’ greater cognitive reserve. PMID:26615021

Joint longitudinal data analysis in detecting determinants of CD4 cell count change and adherence to highly active antiretroviral therapy at Felege Hiwot Teaching and Specialized Hospital, North-west Ethiopia (Amhara Region).

PubMed

Seyoum, Awoke; Ndlovu, Principal; Temesgen, Zewotir

2017-03-16

Adherence and CD4 cell count change measure the progression of the disease in HIV patients after the commencement of HAART. Lack of information about associated factors on adherence to HAART and CD4 cell count reduction is a challenge for the improvement of cells in HIV positive adults. The main objective of adopting joint modeling was to compare separate and joint models of longitudinal repeated measures in identifying long-term predictors of the two longitudinal outcomes: CD4 cell count and adherence to HAART. A longitudinal retrospective cohort study was conducted to examine the joint predictors of CD4 cell count change and adherence to HAART among HIV adult patients enrolled in the first 10 months of the year 2008 and followed-up to June 2012. Joint model was employed to determine joint predictors of two longitudinal response variables over time. Furthermore, the generalized linear mixed effect model had been used for specification of the marginal distribution, conditional to correlated random effect. A total of 792 adult HIV patients were studied to analyze the longitudinal joint model study. The result from this investigation revealed that age, weight, baseline CD4 cell count, ownership of cell phone, visiting times, marital status, residence area and level of disclosure of the disease to family members had significantly affected both outcomes. From the two-way interactions, time * owner of cell phone, time * sex, age * sex, age * level of education as well as time * level of education were significant for CD4 cell count change in the longitudinal data analysis. The multivariate joint model with linear predictor indicates that CD4 cell count change was positively correlated (p ≤ 0.0001) with adherence to HAART. Hence, as adherence to HAART increased, CD4 cell count also increased; and those patients who had significant CD4 cell count change at each visiting time had been encouraged to be good adherents. Joint model analysis was more parsimonious as compared to separate analysis, as it reduces type I error and subject-specific analysis improved its model fit. The joint model operates multivariate analysis simultaneously; and it has great power in parameter estimation. Developing joint model helps validate the observed correlation between the outcomes that have emerged from the association of intercepts. There should be a special attention and intervention for HIV positive adults, especially for those who had poor adherence and with low CD4 cell count change. The intervention may be important for pre-treatment counseling and awareness creation. The study also identified a group of patients who were with maximum risk of CD4 cell count change. It is suggested that this group of patients needs high intervention for counseling.

Effects of individual-level socioeconomic factors on racial disparities in cancer treatment and survival: findings from the National Longitudinal Mortality Study, 1979-2003.

PubMed

Du, Xianglin L; Lin, Charles C; Johnson, Norman J; Altekruse, Sean

2011-07-15

This is the first study to use the linked National Longitudinal Mortality Study and Surveillance, Epidemiology, and End Results (SEER) data to determine the effects of individual-level socioeconomic factors (health insurance, education, income, and poverty status) on racial disparities in receiving treatment and in survival. This study included 13,234 cases diagnosed with the 8 most common types of cancer (female breast, colorectal, prostate, lung and bronchus, uterine cervix, ovarian, melanoma, and urinary bladder) at age ≥ 25 years, identified from the National Longitudinal Mortality Study-SEER data during 1973 to 2003. Kaplan-Meier methods and Cox regression models were used for survival analysis. Three-year all-cause observed survival for cases diagnosed with local-stage cancers of the 8 leading tumors combined was ≥ 82% regardless of race/ethnicity. More favorable survival was associated with higher socioeconomic status. Compared with whites, blacks were less likely to receive first-course cancer-directed surgery, perhaps reflecting a less favorable stage distribution at diagnosis. Hazard ratio (HR) for cancer-specific mortality was significantly higher among blacks compared with whites (HR, 1.2; 95% confidence interval [CI], 1.1-1.3) after adjusting for age, sex, and tumor stage, but not after further controlling for socioeconomic factors and treatment (HR, 1.0; 95% CI, 0.9-1.1). HRs for all-cause mortality among patients with breast cancer and for cancer-specific mortality in patients with prostate cancer were significantly higher for blacks compared with whites after adjusting for socioeconomic factors, treatment, and patient and tumor characteristics. Favorable survival was associated with higher socioeconomic status. Racial disparities in survival persisted after adjusting for individual-level socioeconomic factors and treatment for patients with breast and prostate cancer. Copyright © 2011 American Cancer Society.

Assessment of Children's Psychological Development and Data Analytic Framework in New York City Infant Day Care Study.

ERIC Educational Resources Information Center

Golden, Mark

This report briefly describes the procedures for assessing children's psychological development and the data analytic framework used in the New York City Infant Day Care Study. This study is a 5-year, longitudinal investigation in which infants in group and family day care programs and infants reared at home are compared. Children in the study are…

Method for Studying Helicopter Longitudinal Maneuver Stability

NASA Technical Reports Server (NTRS)

Amer, Kenneth B

1954-01-01

A theoretical analysis of helicopter maneuver stability is made and the results are compared with experimental results for both a single and a tandem rotor helicopter. Techniques are described for measuring in flight the significant stability derivatives for use with the theory to aid in design studies of means for achieving marginal maneuver stability for a prototype helicopter.

The Effect of Task in Deaf Readers' Graphophonological Processes: A Longitudinal Study

ERIC Educational Resources Information Center

Daigle, Daniel; Berthiaume, Rachel; Demont, Elisabeth

2012-01-01

This article reports on an investigation of graphophonological processes in deaf readers of French over a 1-year period. Deaf readers are known to have a phonological deficit compared to hearing peers, and conclusions from studies on this question are often conflicting. Among the different types of phonological processing, we can identify…

Dual Vulnerability of Sexually Victimized Mothers and Sexually Victimized Children: A Longitudinal Study.

ERIC Educational Resources Information Center

Newberger, Eli H.; And Others

Clinical approaches to child sexual abuse have been constrained by limited knowledge of the family dimensions of the problem. This study compared the psychiatric responses of women with and without sexual abuse histories to disclosures of their children's sexual abuse, and assessed the relationship of these histories to the nature of the child's…

An Experimental Study Comparing English-Only and Transitional Bilingual Education on Spanish-Speaking Preschoolers' Early Literacy Development

ERIC Educational Resources Information Center

Duran, Lillian K.; Roseth, Cary J.; Hoffman, Patricia

2010-01-01

A longitudinal, experimental-control design was used to test the hypothesis that native language instruction enhances English language learner's (ELL's) native language and literacy development without significant cost to English development. In this study, 31 Spanish-speaking preschoolers (aged 38-48 months) were randomly assigned to two Head…

Higher-Order Fertility among Urban Fathers: An Overlooked Issue for a Neglected Population

ERIC Educational Resources Information Center

Bronte-Tinkew, Jacinta; Ryan, Suzanne; Franzetta, Kerry; Manlove, Jennifer; Lilja, Emily

2009-01-01

The study includes a longitudinal sample of 1,989 fathers from the Fragile Families and Child Wellbeing study and examines factors associated with fathering a higher-order birth (three or more children) and compares these factors to those predicting any subsequent birth. Also, the article examines differences by marital status. Logistic regression…

A Longitudinal Study of Prism Adaptation in Infants from Six to Nine Months of Age.

ERIC Educational Resources Information Center

McDonnell, Paul M.; Abraham, Wayne C.

1981-01-01

Confirms that aftereffects of prism adaptation can be obtained in infants between 5 and 9 months of age and that the magnitude of these aftereffects is comparable to those found in adult studies. Evidence of a shift in hand preference toward the direction of prism displacement was replicated. (Author/RH)

The Long-Term Impact of Admission Policies: A Comparative Study of Two Emergent Research Institutions in Texas

ERIC Educational Resources Information Center

Crisp, Gloria; Horn, Catherine; Dizinno, Gerry; Barlow, Libby

2013-01-01

The present study explored the long-term impact of admission policies at two aspiring research institutions in Texas. Six years of longitudinal institutional data were analyzed for all full-time first time in college undergraduate students at both universities. Descriptive and inferential statistics were used to identify relationships and…

Drop out and "Disconnected" Young Adults: Examining the Impact of Neighborhood and School Contexts

ERIC Educational Resources Information Center

Rendón, Maria G.

2014-01-01

Using data from the National Longitudinal Study of Adolescent Health (Add Health) this study compares if and how neighborhood effects on the likelihood to drop out and be "disconnected" from school and work in young adulthood change when schools are taken into account. As widely documented, I find that neighborhood socioeconomic status…

A Longitudinal Study of Applicants for the Superintendency.

ERIC Educational Resources Information Center

O'Connell, Raymond W.

This study documents trends in the number and quality of applicants for superintendency over time and the success rate of female applicants throughout the search process. Substantial data indicate a gender bias in selecting superintendents. Data collected in New York in 1999 were compared to 1995 data to determine if the size and quality of the…

On Being Gifted, but Sad and Misunderstood: Social, Emotional, and Academic Outcomes of Gifted Students in the Wollongong Youth Study

ERIC Educational Resources Information Center

Vialle, Wilma; Heaven, Patrick C. L.; Ciarrochi, Joseph

2007-01-01

This research examined the relationships among personality factors, social support, emotional well-being, and academic achievement in 65 gifted secondary students, a sample drawn from a longitudinal study of over 950 students. The research demonstrated that, compared to their nongifted peers, gifted students had significantly higher academic…

Teachers as Agents of Change in Curricular Reform: The Position of Dance Revisited

ERIC Educational Resources Information Center

MacLean, Justine

2018-01-01

This paper reports findings from a recent large-scale survey of Physical Education (PE) teachers' perceptions of teaching dance and compares them to results of a study completed 10 years previously [MacLean, J. (2007). A longitudinal study to ascertain the factors that impact on the confidence of undergraduate physical education student teachers…

A Longitudinal Study of the Impact of Parental Divorce on Adolescents' Evaluations of Self and Parents.

ERIC Educational Resources Information Center

Parish, Thomas S.; Wigle, Stanley E.

1985-01-01

Obtained children's (N=639) evaluations of their parents and themselves over a three-year period. Compared children whose parents divorced prior to or during the study with the children whose families remained intact during that time. Results showed children in intact families evaluated themselves and their parents more positively. (BH)

A STUDY OF COGNITIVE DEVELOPMENT AND PERFORMANCE IN CHILDREN WITH NORMAL AND DEFECTIVE HEARING.

ERIC Educational Resources Information Center

TEMPLIN, MILDRED C.

A COMPARATIVE, LONGITUDINAL STUDY WAS CONDUCTED TO EXAMINE SPECIFIC PERFORMANCE CHARACTERISTICS OF DEAF AND NORMAL CHILDREN ON SELECTED COGNITIVE TASKS. THE SAMPLE, DISTRIBUTED INTO 3 AGE CATEGORIES, CONSISTED OF 72 NORMAL AND 60 DEAF CHILDREN. MEASURES WERE SELECTED TO ASSESS THE PERFORMANCE OF SUBJECTS (1) IN DIFFERENT AREAS OF COGNITION, (2) BY…

The Health of Caregiving Grandmothers: A Rural-Urban Comparison

ERIC Educational Resources Information Center

Bigbee, Jeri L.; Musil, Carol; Kenski, Diane

2011-01-01

Purpose: The purpose of this study was to compare the characteristics of rural versus urban caregiving grandmothers along with their physical and mental health status. Methods: A secondary analysis of data produced from the first wave of a longitudinal study of 485 Ohio grandmothers was conducted. Health status was measured using the SF-36 Health…

Personalized Introductory Courses: A Longitudinal Study. OASIS Research Report No. 1.

ERIC Educational Resources Information Center

Hedges, Larry V.

This study investigated the long term effects of the Personalized System of Instruction (PSI) method at the University of California, San Diego. Groups of 139 and 137 undergraduate students took three physics courses taught by either the PSI method or the lecture/discussion method. Students from these groups were compared in two subsequent…

Analysis of Subsequent Educational Decisions of High School Dropouts and Their Life Outcomes.

ERIC Educational Resources Information Center

Chan, Chi-Keung; Kato, Kentaro; Davenport, Ernest C., Jr.; Guven, Kamil

This study used data for a representative sample of 8th graders from the National Educational Longitudinal Study of 1988. The intent was to (1) compare student's dropout status with variables such as demographics, academic and economic factors, limited English proficiency status, and other risk factors of dropping out, (2) distinguish factors…

Educational Opportunity Program (EOP) at a Selective Public University: Initial Findings from a Longitudinal Evaluation Study

ERIC Educational Resources Information Center

Winograd, Greta; Verkuilen, Jay; Weingarten, Alison; Walker, Lucy

2018-01-01

In this study, we examined academic outcomes among students from low-income and academically disadvantaged backgrounds who participated in the Educational Opportunity Program (EOP) at a selective four-year public comprehensive college in the Northeast. We found that provisionally admitted EOP students earned comparable first-semester grades and…

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'…

Good Things Come in Threes: Single-Parent Multigenerational Family Structure and Adolescent Adjustment. JCPR Working Paper.

ERIC Educational Resources Information Center

DeLeire, Thomas; Kalil, Ariel

This research used data from the 1998 National Educational Longitudinal Study to investigate the development of outcomes for adolescents living with single mothers in multigenerational families compared with adolescents living in married families (as well as a disaggregated set of other family structures). The study measured family structure when…

Recruitment Evaluation of a Preschooler Obesity-Prevention Intervention

ERIC Educational Resources Information Center

Skouteris, Helen; Hill, Briony; McCabe, Marita; Swinburn, Boyd; Sacher, Paul; Chadwick, Paul

2014-01-01

The aim of this paper was to compare the recruitment strategies of two recent studies that focused on the parental influences on childhood obesity during the preschool years. The first study was a randomised controlled trial (RCT) of the Mind, Exercise, Nutrition?…?Do It! 2-4 obesity prevention programme and the second was a longitudinal cohort…

The Validity of Truant Youths' Marijuana Use and Its Impact on Alcohol Use and Sexual Risk Taking

ERIC Educational Resources Information Center

Dembo, Richard; Briones-Robinson, Rhissa; Barrett, Kimberly; Winters, Ken C.; Ungaro, Rocío; Karas, Lora; Belenko, Steven; Wareham, Jennifer

2015-01-01

Few studies investigating the validity of marijuana use have used samples of truant youths. In the current study, self-reports of marijuana use are compared with urine test results for marijuana to identify marijuana underreporting among adolescents participating in a longitudinal brief intervention for drug-involved truant youths. It was…

[Prematurity: longitudinal analysis of executive functions].

PubMed

Sastre-Riba, S

2009-02-27

Understanding cognitive development requires an interdisciplinary and neuropsychological approach. Executive functions facilitates cognitive activity and they are related to progressive cerebral configuration during pregnancy and infancy. One of the aims of the actual neuropsychology is the ontogeny of executive functions and their capacity to explain differential and normative developmental trends, specially because of its consequences on mental flexibility, monitoring, planning and cognitive control; they are also essential for good performance at school. The incidence of developmental risk factors as prematurity could affect long-term executive functioning expressed in learning difficulties or behavioral control. We studied, comparatively and longitudinally, the individual activity on objects displayed by typical babies (n = 25), and preterm babies (n = 10) from 1.5 to 2 years-old. Applying systematic observational methodology, spontaneous babies' activity is registered. Double intra and inter-group analysis compare the data from the resolution of a non-verbal task through a multifaceted design. Results obtained show us differential pattern of early executive functioning among the groups studied. The growth of executive functioning is showed, too, through the ages studied for every group.

A Meta-Analysis of Cognitive Impairment and Decline Associated with Adjuvant Chemotherapy in Women with Breast Cancer

PubMed Central

Ono, Miyuki; Ogilvie, James M.; Wilson, Jennifer S.; Green, Heather J.; Chambers, Suzanne K.; Ownsworth, Tamara; Shum, David H. K.

2015-01-01

A meta-analysis was performed to quantify the magnitude and nature of the association between adjuvant chemotherapy and performance on a range of cognitive domains among breast cancer patients. A total of 27 studies (14 cross-sectional, 8 both cross-sectional and prospective, and 5 prospective) were included in the analyses, involving 1562 breast cancer patients who had undergone adjuvant chemotherapy and 2799 controls that included breast cancer patients who did not receive adjuvant chemotherapy. A total of 737 effect sizes (Cohen’s d) were calculated for cross-sectional and prospective longitudinal studies separately and classified into eight cognitive domains. The mean effect sizes varied across cross-sectional and prospective longitudinal studies (ranging from −1.12 to 0.62 and −0.29 to 1.12, respectively). Each cognitive domain produced small effect sizes for cross-sectional and prospective longitudinal studies (ranging from −0.25 to 0.41). Results from cross-sectional studies indicated a significant association between adjuvant chemotherapy and cognitive impairment that held across studies with varied methodological approaches. For prospective studies, results generally indicated that cognitive functioning improved over time after receiving adjuvant chemotherapy. Greater cognitive impairment was reported in cross-sectional studies comparing chemotherapy groups with healthy control groups. Results suggested that cognitive impairment is present among breast cancer patients irrespective of a history of chemotherapy. Prospective longitudinal research is warranted to examine the degree and persisting nature of cognitive impairment present both before and after chemotherapy, with comparisons made to participants’ cognitive function prior to diagnosis. Accurate understanding of the effects of chemotherapy is essential to enable informed decisions regarding treatment and to improve quality of life among breast cancer patients. PMID:25806355

Quality of Life and Cost Effectiveness of Prostate Cancer Treatment

DTIC Science & Technology

2006-03-01

Visser AP, Hulshof MC, Horenblas S, Kurth KH. Health-related quality of life and psychosocial factors in patients with prostate cancer scheduled for...Andel G, Visser AP, Zwinderman AH, Hulshof MC, Horenblas S, Kurth KH. A prospective longitudinal study comparing the impact of external radiation

Longitudinal study of body mass index in Asian men who immigrate to the US.

PubMed

Oakkar, Eva Erber; Stevens, June; Bradshaw, Patrick T; Cai, Jianwen; Perreira, Krista M; Popkin, Barry M; Gordon-Larsen, Penny; Young, Deborah R; Ghai, Nirupa R; Caan, Bette; Quinn, Virginia P

2015-01-01

Cross-sectional studies indicate that adaptation to Western norms, especially at a younger age, might explain the higher average body mass index (BMI) among Asians living in the United States (US) compared to Asians living in Asia. However, migrants differ from non-migrants in sociocultural factors that are difficult to measure and, thus, longitudinal studies on the same individuals prior to and after immigration are needed. The objective of this study was to determine differences in changes in BMI across age by residence (US or Asia) and age at immigration using longitudinal data on BMI prior to and after immigration. The California Men's Health Study includes 1,549 foreign-born Asian men who were aged 44-71 at baseline in 2002-03. BMI at ages 30, 40, 50 and 60 was calculated using self-reported weight history and current height. Residence at each age decade and age at immigration were determined. Data were analyzed using generalized estimating equations. Ten-year BMI increases were smaller among Asians who lived in Asia prior to migrating to the US compared to those who already lived in the US. This effect was most evident be-tween ages 30-40 when Asians in Asia had a 0.69 kg/m2 (95% CI: -1.08, -0.30) smaller increase in BMI. Immigrants who moved to the US before age 40 experienced greater increases in BMI than immigrants who moved to the US at an older age. This study is the first to support the hypothesis that living in the US and younger age at immigration results in larger BMI increases in Asian men.

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

PubMed

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

2018-01-01

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

The effect of indapamide versus hydrochlorothiazide on ventricular and arterial function in patients with hypertension and diabetes: results of a randomized trial.

PubMed

Vinereanu, Dragos; Dulgheru, Raluca; Magda, Stefania; Dragoi Galrinho, Ruxandra; Florescu, Maria; Cinteza, Mircea; Granger, Christopher; Ciobanu, Andrea O

2014-10-01

The objective of this study is to compare the effects of 2 types of diuretics, indapamide and hydrochlorothiazide, added to an angiotensin-converting enzyme inhibitor, on ventricular and arterial functions in patients with hypertension and diabetes. This is a prospective, randomized, active-controlled, PROBE design study in 56 patients (57 ± 9 years, 52% men) with mild-to-moderate hypertension and type 2 diabetes, with normal ejection fraction, randomized to either indapamide (1.5 mg Slow Release (SR)/day) or hydrochlorothiazide (25 mg/d), added to quinapril (10-40 mg/d). All patients had conventional, tissue Doppler and speckle tracking echocardiography and assessment of endothelial and arterial functions and biomarkers, at baseline and after 6 months. Baseline characteristics were similar between groups; systolic and diastolic blood pressures decreased similarly, by 15% and 9% on indapamide and by 17% and 10% on hydrochlorothiazide (P < .05). Mean longitudinal systolic velocity and longitudinal strain increased by 7% and 14% on indapamide (from 5.6 ± 1.8 to 6.0 ± 1.1 cm/s and from 16.2% ± 1.8% to 18.5% ± 1.1%, both P < .05), but did not change on hydrochlorothiazide (P < .05 for intergroup differences), whereas ejection fraction and radial systolic function did not change. Similarly, mean longitudinal early diastolic velocity increased by 31% on indapamide (P < .05), but did not change on hydrochlorothiazide (P < .05 for intergroup differences). These changes were associated with improved endothelial and arterial functions on indapamide, but not on hydrochlorothiazide. Indapamide was found to improve measures of endothelial and arterial functions and to increase longitudinal left ventricular function compared with hydrochlorothiazide in patients with hypertension and diabetes, after 6 months of treatment. This study suggests that indapamide, a thiazide-like diuretic, has important vascular effects that can improve ventriculoarterial coupling. Copyright © 2014 Mosby, Inc. All rights reserved.

Vitamin D deficiency in UK South Asian Women of childbearing age: a comparative longitudinal investigation with UK Caucasian women.

PubMed

Darling, A L; Hart, K H; Macdonald, H M; Horton, K; Kang'ombe, A R; Berry, J L; Lanham-New, S A

2013-02-01

This is the first 1-year longitudinal study which assesses vitamin D deficiency in young UK-dwelling South Asian women. The findings are that vitamin D deficiency is extremely common in this group of women and that it persists all year around, representing a significant public health concern. There is a lack of longitudinal data assessing seasonal variation in vitamin D status in young South Asian women living in northern latitudes. Studies of postmenopausal South Asian women suggest a lack of seasonal change in 25-hydroxy vitamin D [25(OH)D], although it is unclear whether this is prevalent among premenopausal South Asians. We aimed to evaluate, longitudinally, seasonal changes in 25(OH)D and prevalence of vitamin D deficiency in young UK-dwelling South Asian women as compared with Caucasians. We also aimed to establish the relative contributions of dietary vitamin D and sun exposure in explaining serum 25(OH)D. This is a 1-year prospective cohort study assessing South Asian (n = 35) and Caucasian (n = 105) premenopausal women living in Surrey, UK (51° N), aged 20-55 years. The main outcome measured was serum 25(OH)D concentration. Secondary outcomes were serum parathyroid hormone, self-reported dietary vitamin D intake and UVB exposure by personal dosimetry. Serum 25(OH)D <25 nmol/L was highly prevalent in South Asians in the winter (81 %) and autumn (79.2 %). Deficient status (below 50 nmol/L) was common in Caucasian women. Multi-level modelling suggested that, in comparison to sun exposure (1.59, 95 %CI = 0.83-2.35), dietary intake of vitamin D had no impact on 25(OH)D levels (-0.08, 95 %CI = -1.39 to 1.23). Year-round vitamin D deficiency was extremely common in South Asian women. These findings pose great health threats regarding the adverse effects of vitamin D deficiency in pregnancy and warrant urgent vitamin D public health policy and action.

A two-year longitudinal pilot MRI study of the brainstem in autism.

PubMed

Jou, Roger J; Frazier, Thomas W; Keshavan, Matcheri S; Minshew, Nancy J; Hardan, Antonio Y

2013-08-15

Research has demonstrated the potential role of the brainstem in the pathobiology of autism. Previous studies have suggested reductions in brainstem volume and a relationship between this structure and sensory abnormalities. However, little is known regarding the developmental aspects of the brainstem across childhood and adolescence. The goal of this pilot study was to examine brainstem development via MRI volumetry using a longitudinal research design. Participants included 23 boys with autism and 23 matched controls (age range=8-17 years), all without intellectual disability. Participants underwent structural MRI scans once at baseline and again at two-year follow-up. Brainstem volumetric measurements were performed using the BRAINS2 software package. There were no significant group differences in age, gender, handedness, and total brain volume; however, full-scale IQ was higher in controls. Autism and control groups showed different patterns of growth in brainstem volume. While whole brainstem volume remained stable in controls over the two-year period, the autism group showed increases with age reaching volumes comparable to controls by age 15 years. This increase of whole brainstem volume was primarily driven by bilateral increases in gray matter volume. Findings from this preliminary study are suggestive of developmental brainstem abnormalities in autism primarily involving gray matter structures. These findings are consistent with autism being conceptualized as a neurodevelopmental disorder with alterations in brain-growth trajectories. More longitudinal MRI studies are needed integrating longitudinal cognitive/behavioral data to confirm and elucidate the clinical significance of these atypical growth patterns. Copyright © 2013 Elsevier B.V. All rights reserved.

Comparison of a single-channel EEG sleep study to polysomnography

PubMed Central

Lucey, Brendan P.; McLeland, Jennifer S.; Toedebusch, Cristina D.; Boyd, Jill; Morris, John C.; Landsness, Eric C.; Yamada, Kelvin; Holtzman, David M.

2016-01-01

Summary An accurate home sleep study to assess electroencephalography (EEG)-based sleep stages and EEG power would be advantageous for both clinical and research purposes, such as for longitudinal studies measuring changes in sleep stages over time. The purpose of this study was to compare sleep scoring of a single-channel EEG recorded simultaneously on the forehead against attended polysomnography. Participants were recruited from both a clinical sleep center and a longitudinal research study investigating cognitively-normal aging and Alzheimer's disease. Analysis for overall epoch-by-epoch agreement found strong and substantial agreement between the single-channel EEG compared to polysomnography (kappa=0.67). Slow wave activity in the frontal regions was also similar when comparing the single-channel EEG device to polysomnography. As expected, stage N1 showed poor agreement (sensitivity 0.2) due to lack of occipital electrodes. Other sleep parameters such as sleep latency and REM onset latency had decreased agreement. Participants with disrupted sleep consolidation, such as from obstructive sleep apnea, also had poor agreement. We suspect that disagreement in sleep parameters between the single-channel EEG and polysomnography is partially due to altered waveform morphology and/or poorer signal quality in the single-channel derivation. Our results show that single-channel EEG provides comparable results to polysomnography in assessing REM, combined stages N2 and N3 sleep, and several other parameters including frontal slow wave activity. The data establish that single-channel EEG can be a useful research tool. PMID:27252090

Longitudinal associations between conduct problems and depressive symptoms among girls and boys with early conduct problems.

PubMed

Poirier, Martine; Déry, Michèle; Temcheff, Caroline E; Toupin, Jean; Verlaan, Pierrette; Lemelin, Jean-Pascal

2016-07-01

Youth with conduct problems (CP) may experience high rates of depressive symptoms (DS). However, little is known about the direction of the longitudinal associations between CP and DS in this specific population. Although girls with CP appear at greater risk than boys for presenting comorbid depression, empirical research on gender differences in these associations is even sparser. The current study used autoregressive latent trajectory models to compare four perspectives with hypotheses regarding the longitudinal associations between CP and DS, while taking into account the evolution of both problems. We also examined gender differences in the longitudinal associations. A total of 345 children (40.6 % female) presenting with a high level of CP in early elementary school (mean age at study inception = 8.52; SD = .94) were evaluated annually over a four-year period (5 measurement time points). The results revealed that CP and DS were quite stable over time. Moreover, CP and DS showed strong covariation at each measurement time point, but only one significant positive cross-lagged association between the two processes, indicating that higher levels of DS at time 3 were associated with higher levels of CP 1 year later. No differences were observed in the longitudinal associations between CP and DS in boys and girls. Given the comorbidity and stability of CP and DS, these findings suggest that DS should be systematically evaluated among children with early clinically significant CP, and treatment plans should include interventions aimed at both CP and DS among children who present with both types of problems.

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

PubMed

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

2016-01-01

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

Longitudinal and Cross-Sectional Analyses of Visual Field Progression in Participants of the Ocular Hypertension Treatment Study (OHTS)

PubMed Central

Chauhan, Balwantray C; Keltner, John L; Cello, Kim E; Johnson, Chris A; Anderson, Douglas R; Gordon, Mae O; Kass, Michael A

2014-01-01

Purpose Visual field progression can be determined by evaluating the visual field by serial examinations (longitudinal analysis), or by a change in classification derived from comparison to age-matched normal data in single examinations (cross-sectional analysis). We determined the agreement between these two approaches in data from the Ocular Hypertension Treatment Study (OHTS). Methods Visual field data from 3088 eyes of 1570 OHTS participants (median follow-up 7 yrs, 15 tests with static automated perimetry) were analysed. Longitudinal analyses were performed with change probability with total and pattern deviation, and cross-sectional analysis with Glaucoma Hemifield Test, Corrected Pattern Standard Deviation, and Mean Deviation. The rates of Mean Deviation and General Height change were compared to estimate the degree of diffuse loss in emerging glaucoma. Results The agreement on progression in longitudinal and cross-sectional analyses ranged from 50% to 61% and remained nearly constant across a wide range of criteria. In contrast, the agreement on absence of progression ranged from 97% to 99.7%, being highest for the stricter criteria. Analyses of pattern deviation were more conservative than total deviation, with a 3 to 5 times lesser incidence of progression. Most participants developing field loss had both diffuse and focal change. Conclusions Despite considerable overall agreement, between 40 to 50% of eyes identified as having progressed with either longitudinal or cross-sectional analyses were identified with only one of the analyses. Because diffuse change is part of early glaucomatous damage, pattern deviation analyses may underestimate progression in patients with ocular hypertension. PMID:21149774

Longitudinal variations of brain functional connectivity: A case report study based on a mouse model of epilepsy.

PubMed

Erramuzpe, A; Encinas, J M; Sierra, A; Maletic-Savatic, M; Brewster, A L; Anderson, Anne E; Stramaglia, S; Cortes, Jesus M

2015-01-01

Brain Functional Connectivity (FC) quantifies statistical dependencies between areas of the brain. FC has been widely used to address altered function of brain circuits in control conditions compared to different pathological states, including epilepsy, a major neurological disorder. However, FC also has the as yet unexplored potential to help us understand the pathological transformation of the brain circuitry. Our hypothesis is that FC can differentiate global brain interactions across a time-scale of days. To this end, we present a case report study based on a mouse model for epilepsy and analyze longitudinal intracranial electroencephalography data of epilepsy to calculate FC changes from the initial insult (status epilepticus) and over the latent period, when epileptogenic networks emerge, and at chronic epilepsy, when unprovoked seizures occur as spontaneous events. We found that the overall network FC at low frequency bands decreased immediately after status epilepticus was provoked, and increased monotonously later on during the latent period. Overall, our results demonstrate the capacity of FC to address longitudinal variations of brain connectivity across the establishment of pathological states.

Nicotine dependence and transitional shifts in exercise behavior among young U.S. adult smokers.

PubMed

Loprinzi, Paul D; Walker, Jerome F; Cardinal, Bradley J

2014-08-01

The aim of this study is to examine the association between nicotine dependence and longitudinal exercise transitional shift patterns among young U.S. adult daily smokers. Data from the 2003-2005 National Youth Smoking Cessation Survey was used, which is a longitudinal study over a two year period. Participants included 1168 US adult daily smokers (18-24years). Nicotine dependence was assessed using the modified Fagerstrom Test for Nicotine Dependence. Four transitional shift patterns were created based on meeting current exercise guidelines; stable inactive (inactive across time), activity relapsers (starts out active and then becomes inactive), activity adopters (inactive and then becomes active), and stable active (active across time). After adjustments, for every 1-unit increase in baseline nicotine dependence, participants had 16% (OR=1.16, p=0.01) greater odds of being in the stable inactive group compared to the stable active group. Nicotine dependence appears to play an important role in shaping longitudinal exercise patterns among young U.S. adult smokers. Copyright © 2014 Elsevier Inc. All rights reserved.

Rotator cuff tear shape characterization: a comparison of two-dimensional imaging and three-dimensional magnetic resonance reconstructions.

PubMed

Gyftopoulos, Soterios; Beltran, Luis S; Gibbs, Kevin; Jazrawi, Laith; Berman, Phillip; Babb, James; Meislin, Robert

2016-01-01

The purpose of this study was to see if 3-dimensional (3D) magnetic resonance imaging (MRI) could improve our understanding of rotator cuff tendon tear shapes. We believed that 3D MRI would be more accurate than two-dimensional (2D) MRI for classifying tear shapes. We performed a retrospective review of MRI studies of patients with arthroscopically proven full-thickness rotator cuff tears. Two orthopedic surgeons reviewed the information for each case, including scope images, and characterized the shape of the cuff tear into crescent, longitudinal, U- or L-shaped longitudinal, and massive type. Two musculoskeletal radiologists reviewed the corresponding MRI studies independently and blind to the arthroscopic findings and characterized the shape on the basis of the tear's retraction and size using 2D MRI. The 3D reconstructions of each cuff tear were reviewed by each radiologist to characterize the shape. Statistical analysis included 95% confidence intervals and intraclass correlation coefficients. The study reviewed 34 patients. The accuracy for differentiating between crescent-shaped, longitudinal, and massive tears using measurements on 2D MRI was 70.6% for reader 1 and 67.6% for reader 2. The accuracy for tear shape characterization into crescent and longitudinal U- or L-shaped using 3D MRI was 97.1% for reader 1 and 82.4% for reader 2. When further characterizing the longitudinal tears as massive or not using 3D MRI, both readers had an accuracy of 76.9% (10 of 13). The overall accuracy of 3D MRI was 82.4% (56 of 68), significantly different (P = .021) from 2D MRI accuracy (64.7%). Our study has demonstrated that 3D MR reconstructions of the rotator cuff improve the accuracy of characterizing rotator cuff tear shapes compared with current 2D MRI-based techniques. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Premature Discontinuation of Prospective Clinical Studies Approved by a Research Ethics Committee – A Comparison of Randomised and Non-Randomised Studies

PubMed Central

Oeller, Patrick; Kasenda, Benjamin; Briel, Matthias; von Elm, Erik

2016-01-01

Background Premature discontinuation of clinical studies affects about 25% of randomised controlled trials (RCTs) which raises concerns about waste of scarce resources for research. The risk of discontinuation of non-randomised prospective studies (NPSs) is yet unclear. Objectives To compare the proportion of discontinued studies between NPSs and RCTs that received ethical approval. Methods We systematically surveyed prospective longitudinal clinical studies that were approved by a single REC in Freiburg, Germany between 2000 and 2002. We collected study characteristics, identified subsequent publications, and surveyed investigators to elucidate whether a study was discontinued and, if so, why. Results Of 917 approved studies, 547 were prospective longitudinal studies (306 RCTs and 241 NPSs). NPSs were on average smaller than RCTs, more frequently single centre and pilot studies, and less frequently funded by industry. NPSs were less frequently discontinued than RCTs: 32/221 (14%) versus 78/288 (27%, p<0.001, missing data excluded). Poor recruitment was the most frequent reason for discontinuation in both NPSs (36%) and RCTs (37%). Conclusions Compared to RCTs, NPSs were at lower risk for discontinuation. Measures to reliably predict, sustain, and stimulate recruitment could prevent discontinuation of many RCTs but also of some NPSs. PMID:27792749

Longitudinal and bulk viscosities of Lennard-Jones fluids

NASA Astrophysics Data System (ADS)

Tankeshwar, K.; Pathak, K. N.; Ranganathan, S.

1996-12-01

Expressions for the longitudinal and bulk viscosities have been derived using Green Kubo formulae involving the time integral of the longitudinal and bulk stress autocorrelation functions. The time evolution of stress autocorrelation functions are determined using the Mori formalism and a memory function which is obtained from the Mori equation of motion. The memory function is of hyperbolic secant form and involves two parameters which are related to the microscopic sum rules of the respective autocorrelation function. We have derived expressions for the zeroth-, second-and fourth- order sum rules of the longitudinal and bulk stress autocorrelation functions. These involve static correlation functions up to four particles. The final expressions for these have been put in a form suitable for numerical calculations using low- order decoupling approximations. The numerical results have been obtained for the sum rules of longitudinal and bulk stress autocorrelation functions. These have been used to calculate the longitudinal and bulk viscosities and time evolution of the longitudinal stress autocorrelation function of the Lennard-Jones fluids over wide ranges of densities and temperatures. We have compared our results with the available computer simulation data and found reasonable agreement.

Strain hardening and fracture behavior during tension of directionally solidified high-nitrogen austenitic steel

NASA Astrophysics Data System (ADS)

Maier, Galina; Astafurova, Elena; Melnikov, Eugene; Moskvina, Valentina; Galchenko, Nina

2017-12-01

The effect of grain orientation relative to tensile load on the strain hardening behavior and fracture mechanism of directionally solidified high-nitrogen steel Fe-20Cr-22Mn-1.5V-0.2C-0.6N (in wt %) was studied. The tensile samples oriented along the longitudinal direction of columnar grains demonstrated the improved mechanical properties compared to specimens with the transversal directions of columnar grains: the values of tensile strength and strain-to-fracture were as high as 1080 MPa and 22%, respectively, for tension along the columnar grains and 870 MPa and 11%, respectively, for the tension transversal to the columnar grains. The change in the grain orientation relative to the tensile load varies a fracture mode of the steel. The fraction of the transgranular fracture was higher in the samples with longitudinal directions of the columnar grains compared to the transversal ones.

Element free Galerkin formulation of composite beam with longitudinal slip

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

Ahmad, Dzulkarnain; Mokhtaram, Mokhtazul Haizad; Badli, Mohd Iqbal

2015-05-15

Behaviour between two materials in composite beam is assumed partially interact when longitudinal slip at its interfacial surfaces is considered. Commonly analysed by the mesh-based formulation, this study used meshless formulation known as Element Free Galerkin (EFG) method in the beam partial interaction analysis, numerically. As meshless formulation implies that the problem domain is discretised only by nodes, the EFG method is based on Moving Least Square (MLS) approach for shape functions formulation with its weak form is developed using variational method. The essential boundary conditions are enforced by Langrange multipliers. The proposed EFG formulation gives comparable results, after beenmore » verified by analytical solution, thus signify its application in partial interaction problems. Based on numerical test results, the Cubic Spline and Quartic Spline weight functions yield better accuracy for the EFG formulation, compares to other proposed weight functions.« less

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

Longitudinal Study of Reproductive Performance of Female Cattle Produced by Somatic Cell Nuclear Transfer

PubMed Central

Polejaeva, Irina A.; Broek, Diane M.; Walker, Shawn C.; Zhou, Wenli; Walton, Mark; Benninghoff, Abby D.; Faber, David C.

2013-01-01

The objective of this study was to determine whether or not reproductive performance in cattle produced by somatic cell nuclear transfer (SCNT) is significantly different from that of their genetic donors. To address this question, we directed two longitudinal studies using different embryo production procedures: (1) superovulation followed by artificial insemination (AI) and embryo collection and (2) ultrasound-guided ovum pick-up followed by in vitro fertilization (OPU-IVF). Collectively, these two studies represent the largest data set available for any species on the reproductive performance of female clones and their genetic donors as measured by their embryo production outcomes in commercial embryo production program. The large-scale study described herein was conducted over a six-year period of time and provides a unique comparison of 96 clones to the 40 corresponding genetic donors. To our knowledge, this is the first longitudinal study on the reproductive performance of cattle clones using OPU-IVF. With nearly 2,000 reproductive procedures performed and more than 9,200 transferable embryos produced, our observations show that the reproductive performance of cattle produced by SCNT is not different compared to their genetic donors for the production of transferable embryos after either AI followed by embryo collection (P = 0.77) or OPU-IVF (P = 0.97). These data are in agreement with previous reports showing that the reproductive capabilities of cloned cattle are equal to that of conventionally produced cattle. In conclusion, results of this longitudinal study once again demonstrate that cloning technology, in combination with superovulation, AI and embryo collection or OPU-IVF, provides a valuable tool for faster dissemination of superior maternal genetics. PMID:24391930

Longitudinal study of reproductive performance of female cattle produced by somatic cell nuclear transfer.

PubMed

Polejaeva, Irina A; Broek, Diane M; Walker, Shawn C; Zhou, Wenli; Walton, Mark; Benninghoff, Abby D; Faber, David C

2013-01-01

The objective of this study was to determine whether or not reproductive performance in cattle produced by somatic cell nuclear transfer (SCNT) is significantly different from that of their genetic donors. To address this question, we directed two longitudinal studies using different embryo production procedures: (1) superovulation followed by artificial insemination (AI) and embryo collection and (2) ultrasound-guided ovum pick-up followed by in vitro fertilization (OPU-IVF). Collectively, these two studies represent the largest data set available for any species on the reproductive performance of female clones and their genetic donors as measured by their embryo production outcomes in commercial embryo production program. The large-scale study described herein was conducted over a six-year period of time and provides a unique comparison of 96 clones to the 40 corresponding genetic donors. To our knowledge, this is the first longitudinal study on the reproductive performance of cattle clones using OPU-IVF. With nearly 2,000 reproductive procedures performed and more than 9,200 transferable embryos produced, our observations show that the reproductive performance of cattle produced by SCNT is not different compared to their genetic donors for the production of transferable embryos after either AI followed by embryo collection (P = 0.77) or OPU-IVF (P = 0.97). These data are in agreement with previous reports showing that the reproductive capabilities of cloned cattle are equal to that of conventionally produced cattle. In conclusion, results of this longitudinal study once again demonstrate that cloning technology, in combination with superovulation, AI and embryo collection or OPU-IVF, provides a valuable tool for faster dissemination of superior maternal genetics.

An exploratory study on risk factors for chronic non-communicable diseases among adolescents in Malaysia: overview of the Malaysian Health and Adolescents Longitudinal Research Team study (The MyHeART study).

PubMed

Hazreen, Majid Abdul; Su, Tin Tin; Jalaludin, Muhammad Yazid; Dahlui, Maznah; Chinna, Karuthan; Ismail, Maslinor; Murray, Liam; Cantwell, Marie; Al Sadat, Nabilla

2014-01-01

The National Health & Morbidity Survey (NHMS) IV (2011) observed that the prevalence of obese children aged less than 18 years in Malaysia is 6.1% compared to 5.4% overweight and obese in NHMS III (2006). As such, this observation is of public health importance as obesity is a forewarning risk factor for chronic diseases such as type-2 diabetes, cardiovascular diseases (CVD) and certain types of cancers. This MyHeART (Malaysian Health and Adolescents longitudinal Research Team) study aims to examine risk factors of non-communicable diseases (NCD) among adolescents. The MyHeART study is longitudinal cohort study of 1361 schoolchildren (13-years old) attending 15 public secondary schools from the central (Kuala Lumpur and Selangor) and northern (Perak) regions of Peninsular Malaysia. The study used a stratified sampling design to select the study participants. Data collected at baseline included socio-economic, lifestyle (e.g. smoking, physical activity assessment, fitness assessment, seven-day diet history), and environmental information, anthropometric measurements, blood pressure, handgrip strength and bone mineral density. Blood samples for fasting blood glucose and lipid profiles, full blood count, renal profile, as well as bone profile and serum vitamin D were taken. This study cohort will be followed up again when participants turn 15, 17 and lastly, after a period of ten years (around the age of 27). Nine percent of the adolescents from this study were obese. More male participants smoked compared to female participants (15.4% vs. 4.7%). Adolescent males had higher fasting blood glucose but the female participants had lower high density lipoprotein (HDL-cholesterol) and higher low density lipoprotein (LDL-cholesterol). In addition, adolescents from the rural area had higher fasting blood glucose, diastolic blood pressure, total cholesterol and LDL-cholesterol. Our results demonstrated that adolescents from the rural area are at higher risk of NCDs compared to their urban counterpart. Tailor made public health interventions are highly recommended for adolescents as this may minimise the dreadful NCD burden in adulthood and health disparity between the rural and urban in the near future.

Pregnancy diet and associated outcomes in the Avon Longitudinal Study of Parents and Children

PubMed Central

Jones, Louise R.; Golding, Jean

2015-01-01

All publications covering diet during pregnancy that stemmed from the Avon Longitudinal Study of Parents and Children were reviewed. Diet was assessed using a food frequency questionnaire. Socioeconomic background, maternal mental health, and the health and development of the offspring were assessed using a variety of methods, such as direct measurement, self-completion questionnaires, and assays of biological samples. Differences in diet, including specific food and nutrient intakes and dietary patterns, were associated with maternal educational attainment, smoking habits, and financial difficulty. There were marginal intakes, compared with recommendations, of the key nutrients iron, magnesium, potassium, and folate. Maternal diet during pregnancy was predictive of offspring diet during childhood. There were independent associations between prenatal fish consumption and lower frequency of maternal depressive and anxiety symptoms, as well as lower frequency of intrauterine growth retardation. Consistent evidence that fish consumption during pregnancy benefited the neurocognitive development of the child was also found. Two constituents of fish, n-3 polyunsaturated fatty acids and iodine, were associated with these benefits in children. The findings from the Avon Longitudinal Study of Parents and Children strengthen the recommendation to eat fish regularly during pregnancy. PMID:26395341

Bayesian inference for two-part mixed-effects model using skew distributions, with application to longitudinal semicontinuous alcohol data.

PubMed

Xing, Dongyuan; Huang, Yangxin; Chen, Henian; Zhu, Yiliang; Dagne, Getachew A; Baldwin, Julie

2017-08-01

Semicontinuous data featured with an excessive proportion of zeros and right-skewed continuous positive values arise frequently in practice. One example would be the substance abuse/dependence symptoms data for which a substantial proportion of subjects investigated may report zero. Two-part mixed-effects models have been developed to analyze repeated measures of semicontinuous data from longitudinal studies. In this paper, we propose a flexible two-part mixed-effects model with skew distributions for correlated semicontinuous alcohol data under the framework of a Bayesian approach. The proposed model specification consists of two mixed-effects models linked by the correlated random effects: (i) a model on the occurrence of positive values using a generalized logistic mixed-effects model (Part I); and (ii) a model on the intensity of positive values using a linear mixed-effects model where the model errors follow skew distributions including skew- t and skew-normal distributions (Part II). The proposed method is illustrated with an alcohol abuse/dependence symptoms data from a longitudinal observational study, and the analytic results are reported by comparing potential models under different random-effects structures. Simulation studies are conducted to assess the performance of the proposed models and method.

Development of longitudinally excited CO2 laser

NASA Astrophysics Data System (ADS)

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

2018-05-01

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

Longitudinal Patterns of Glycemic Control and Blood Pressure in Pregnant Women with Type 1 Diabetes Mellitus: Phenotypes from Functional Data Analysis.

PubMed

Szczesniak, Rhonda D; Li, Dan; Duan, Leo L; Altaye, Mekibib; Miodovnik, Menachem; Khoury, Jane C

2016-11-01

Objective  To identify phenotypes of type 1 diabetes control and associations with maternal/neonatal characteristics based on blood pressure (BP), glucose, and insulin curves during gestation, using a novel functional data analysis approach that accounts for sparse longitudinal patterns of medical monitoring during pregnancy. Methods  We performed a retrospective longitudinal cohort study of women with type 1 diabetes whose BP, glucose, and insulin requirements were monitored throughout gestation as part of a program-project grant. Scores from sparse functional principal component analysis (fPCA) were used to classify gestational profiles according to the degree of control for each monitored measure. Phenotypes created using fPCA were compared with respect to maternal and neonatal characteristics and outcome. Results  Most of the gestational profile variation in the monitored measures was explained by the first principal component (82-94%). Profiles clustered into three subgroups of high, moderate, or low heterogeneity, relative to the overall mean response. Phenotypes were associated with baseline characteristics, longitudinal changes in glycohemoglobin A1 and weight, and to pregnancy-related outcomes. Conclusion  Three distinct longitudinal patterns of glucose, insulin, and BP control were found. By identifying these phenotypes, interventions can be targeted for subgroups at highest risk for compromised outcome, to optimize diabetes management during pregnancy. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Calculations of the conditions for bunch leakage in the Los Alamos proton storage ring

NASA Astrophysics Data System (ADS)

Neuffer, D.; Ohmori, C.

1994-04-01

Observations are consistent with the possibility of an "ep" instability in the Los Alamos Proton Storage Ring (PSR) with both bunched and unbunched beam. The instability requires electrons to be trapped within the beam, and calculations have shown that such trapping requires leakage of beam into the interbunch gap. Observationally, leakage of beam into the gap appears necessary for the onset of the instability. In this paper we present results of studies of the longitudinal beam dynamics at PSR parameters. The studies indicate that the combined effects of the rf buncher, longitudinal space charge, and injection mismatch are sufficient to cause the observed bunch leakage. Simulation results are presented and compared with PSR observations. Variations of PSR performance parameters are considered, and methods of improving bunch confinement are suggested and studied.

Selecting a separable parametric spatiotemporal covariance structure for longitudinal imaging data.

PubMed

George, Brandon; Aban, Inmaculada

2015-01-15

Longitudinal imaging studies allow great insight into how the structure and function of a subject's internal anatomy changes over time. Unfortunately, the analysis of longitudinal imaging data is complicated by inherent spatial and temporal correlation: the temporal from the repeated measures and the spatial from the outcomes of interest being observed at multiple points in a patient's body. We propose the use of a linear model with a separable parametric spatiotemporal error structure for the analysis of repeated imaging data. The model makes use of spatial (exponential, spherical, and Matérn) and temporal (compound symmetric, autoregressive-1, Toeplitz, and unstructured) parametric correlation functions. A simulation study, inspired by a longitudinal cardiac imaging study on mitral regurgitation patients, compared different information criteria for selecting a particular separable parametric spatiotemporal correlation structure as well as the effects on types I and II error rates for inference on fixed effects when the specified model is incorrect. Information criteria were found to be highly accurate at choosing between separable parametric spatiotemporal correlation structures. Misspecification of the covariance structure was found to have the ability to inflate the type I error or have an overly conservative test size, which corresponded to decreased power. An example with clinical data is given illustrating how the covariance structure procedure can be performed in practice, as well as how covariance structure choice can change inferences about fixed effects. Copyright © 2014 John Wiley & Sons, Ltd.

Practical Formulations of the Latent Growth Item Response Model

ERIC Educational Resources Information Center

McGuire, Leah Walker

2010-01-01

Growth modeling using longitudinal data seems to be a promising direction for improving the methodology associated with the accountability movement. Longitudinal modeling requires that the measurements of ability are comparable over time and on the same scale. One way to create the vertical scale is through concurrent estimation with…

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

EPA Science Inventory

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

Spending Patterns of Metropolitan Universities: A Longitudinal Study.

ERIC Educational Resources Information Center

Schuh, John H.

2002-01-01

Using data from the Integrated Post-secondary Education Data System relational database, assessed the financial resources and expenditure patterns of members of the Coalition of Urban and Metropolitan Universities and compared them to non-metropolitan peers. Verified that metropolitan institutions have fewer resources to work with than others in…

Sensory Processing Sensitivity as a Marker of Differential Susceptibility to Parenting

ERIC Educational Resources Information Center

Slagt, Meike; Dubas, Judith Semon; van Aken, Marcel A. G.; Ellis, Bruce J.; Dekovic, Maja

2018-01-01

In this longitudinal multiinformant study negative emotionality and sensory processing sensitivity were compared as susceptibility markers among kindergartners. Participating children (N = 264, 52.9% boys) were Dutch kindergartners (M[subscript age] = 4.77, SD = 0.60), followed across three waves, spaced seven months apart. Results show that…

Violence Exposure and Psychopathology in Urban Youth: The Mediating Role of Posttraumatic Stress

ERIC Educational Resources Information Center

Ruchkin, Vladislav; Henrich, Christopher C.; Jones, Stephanie M.; Vermeiren, Robert; Schwab-Stone, Mary

2007-01-01

Understanding the mechanisms underlying the development of violence exposure sequelae is essential to providing effective treatments for traumatized youth. This longitudinal study examined the mediating role of posttraumatic stress in the relationship between violence exposure and psychopathology, and compared the mediated models by gender. Urban…

Acculturation or Development? Autonomy Expectations among Ethnic German Immigrant Adolescents and Their Native German Age-Mates

ERIC Educational Resources Information Center

Titzmann, Peter F.; Silbereisen, Rainer K.

2012-01-01

This longitudinal study compared immigrant and native adolescents' expectations concerning the timing of conventional socially acceptable and oppositional less socially acceptable forms of autonomy. Based on normative development and a collectivist background among immigrants, both developmental and acculturative change was expected. The sample…

Crying Behavior and the "Nonviolent" Leboyer Method of Delivery.

ERIC Educational Resources Information Center

Hamilton, Joan Safran

This paper reports on a 3-month longitudinal study comparing the crying behavior of a group of babies delivered by the "nonviolent" Leboyer method with a control group delivered by traditional methods. Subjects were 24 white, middle class infants delivered by minimally medicated, multiparous and primiparous mothers. Fourteen newborns…

Service Provisions for Youth with Emotional and Behavioral Disorders

ERIC Educational Resources Information Center

Dean, Latoya Lavan

2012-01-01

Youth with emotional or behavioral disorders (EBD) have poorer outcomes compared to their peers with and without disabilities. As a result, the federal government has mandated transition services to improve supports and ultimately student outcomes. Using data from the National Longitudinal Transition Study-2 (NLTS-2), this secondary analysis…

Along for the Ride: Best Friends' Resources and Adolescents' College Completion

ERIC Educational Resources Information Center

Cherng, Hua-Yu Sebastian; Calarco, Jessica McCrory; Kao, Grace

2013-01-01

Research on social capital in education rarely considers how the resources students can access through their friendships affect educational outcomes later in life. Using the National Longitudinal Study of Adolescent Health, we explore how having resource-rich best friends impacts adolescents' college completion. We compare the influence of…

Life Satisfaction among Mothers of Individuals with Prader-Willi Syndrome

ERIC Educational Resources Information Center

Shivers, Carolyn M.; Leonczyk, Caroline L.; Dykens, Elisabeth M.

2016-01-01

Mothers of individuals with Prader-Willi syndrome (PWS) often experience numerous stressors, even when compared to mothers of children with other intellectual and developmental disabilities. Despite this, these mothers show great variability in self-reported life satisfaction. Using data from a longitudinal study of individuals with PWS and their…

Trajectories of Victimization in Ethnic Diaspora Immigrant and Native Adolescents: Separating Acculturation from Development

ERIC Educational Resources Information Center

Jugert, Philipp; Titzmann, Peter F.

2017-01-01

This longitudinal study aimed to differentiate between acculturative and developmental processes by (a) comparing levels and change rates in victimization among ethnic German immigrants and native German adolescents in Germany and Russian Jewish immigrants in Israel, and (b) testing whether interindividual differences in victimization among…

Semantic Bias in the Acquisition of Relative Clauses in Japanese

ERIC Educational Resources Information Center

Ozeki, Hiromi; Shirai, Yasuhiro

2010-01-01

This study analyzes the acquisition of relative clauses in Japanese to determine the semantic and functional characteristics of children's relative clauses in spontaneous speech. Longitudinal data from five Japanese children are analyzed and compared with English data (Diessel & Tomasello, 2000). The results show that the relative clauses produced…

Longitudinal Comparative Study: Females' vs. Males' Graduation Outcomes in Undergraduate Engineering

ERIC Educational Resources Information Center

Madara, Diana Starovoytova; Namango, Saul Sitati

2016-01-01

Increasing postsecondary enrolments, reducing university drop-outs, while, simultaneously, boosting graduation rates, is a worldwide dilemma, currently challenging any university and any educational system. One of the most pressing issues facing universities, however, is the number of students, who fail to graduate. The literature survey on gender…

The Relations of Vocational Interests and Mathematical Literacy: On the Predictive Power of Interest Profiles

ERIC Educational Resources Information Center

Warwas, Jasmin; Nagy, Gabriel; Watermann, Rainer; Hasselhorn, Marcus

2009-01-01

This study examines the relationships of vocational interests and mathematical literacy both cross-sectionally and longitudinally. Extending previous research, the results of Holland's RIASEC (Realistic, Investigative, Artistic, Social, Enterprising, and Conventional) scale scores are compared with results from a reductionist approach using…

Adjustment to College Before and After September 11, 2001

ERIC Educational Resources Information Center

Johnson, Vanessa K.; Kerr, Sandra; Gans, Susan E.; Bierschwale, Deborah

2009-01-01

The present study compares college adjustment among emerging adults beginning college in 2000 (before the September 11, 2001 terrorist attacks) and in 2001 (three weeks before 9/11). A prospective longitudinal design was used to follow 41 students throughout their first college year. Participants completed questionnaires about symptoms of anxiety…

College Quality and Early Adult Outcomes

ERIC Educational Resources Information Center

Long, Mark C.

2008-01-01

This paper estimates the effects of various college qualities on several early adult outcomes, using panel data from the National Education Longitudinal Study. I compare the results using ordinary least squares with three alternative methods of estimation, including instrumental variables, and the methods used by Dale and Krueger [(2002).…