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Sample records for estudo longitudinal das

  1. Pain persists in DAS28 rheumatoid arthritis remission but not in ACR/EULAR remission: a longitudinal observational study.

    PubMed

    Lee, Yvonne C; Cui, Jing; Lu, Bing; Frits, Michelle L; Iannaccone, Christine K; Shadick, Nancy A; Weinblatt, Michael E; Solomon, Daniel H

    2011-06-08

    Disease remission has become a feasible goal for most rheumatoid arthritis (RA) patients; however, patient-reported symptoms, such as pain, may persist despite remission. We assessed the prevalence of pain in RA patients in remission according to the Disease Activity Score (DAS28-CRP4) and the American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) remission criteria. Data were analyzed from RA patients in the Brigham Rheumatoid Arthritis Sequential Study with data at baseline and 1 year. DAS28 remission was defined as DAS28-CRP4 <2.6. The ACR/EULAR remission criteria included (a) one or more swollen joints, (b) one or more tender joints, (c) C-reactive protein ≤1 mg/dl, and (d) patient global assessment score ≤1. Pain severity was measured by using the pain score from the Multi-Dimensional Health Assessment Questionnaire (MDHAQ). The associations between baseline clinical predictors and MDHAQ pain at baseline and 1 year were assessed by using multivariable linear regression. Among the 865 patients with data at baseline and 1 year, 157 (18.2%) met DAS28-CRP4 remission criteria at both time points. Thirty-seven (4.3%) met the ACR/EULAR remission criteria at baseline and 1 year. The prevalence of clinically significant pain (MDHAQ pain ≥4) at baseline ranged from 11.9% among patients meeting DAS28-CRP4 remission criteria to none among patients meeting ACR/EULAR remission criteria. Patient global assessment, MDHAQ function, MDHAQ fatigue, MDHAQ sleep, and arthritis self-efficacy were significantly associated with MDHAQ pain in cross-sectional (P ≤ 0.0005) and longitudinal analyses (P ≤ 0.03). Low swollen-joint counts were associated with high MDHAQ pain in longitudinal analyses (P = 0.02) but not cross-sectional analyses. Other measures of inflammatory disease activity and joint damage were not significantly associated with MDHAQ pain at baseline or at 1 year. Clinically significant pain continues among a substantial proportion of

  2. Comment on the use of self-reporting instruments to assess patients with rheumatoid arthritis: the longitudinal association between the DAS28 and the VAS general health.

    PubMed

    Kievit, W; Welsing, P M J; Adang, E M M; Eijsbouts, A M; Krabbe, P F M; van Riel, P L C M

    2006-10-15

    Recently, the use of patient self-reporting instruments instead of clinical, objective measurements to assess rheumatoid arthritis (RA) patients was proposed. This assumes a constant association between disease activity and the self-reporting instruments. The objective was to explore the association (in time) between disease activity and patient perception of general health, disease activity, pain, and functional disability in patients with RA. Data of 624 newly diagnosed RA patients who completed 3 years of followup were analyzed. Cross-sectional linear regression models and longitudinal regression models were estimated, with a visual analog scale (VAS) measuring general health (VAS-GH; 0 = best, 100 = worst) as a dependent variable and the Disease Activity Score (DAS28) without the VAS-GH as an independent variable. Other dependent variables were VAS disease activity, pain, and the Health Assessment Questionnaire. The DAS28 and VAS-GH were significantly associated in RA patients (P < 0.001). However, the explained variance was low (6.7%). From diagnosis to 3 years after the diagnosis, the intercept decreased given the same regression coefficient. The longitudinal regression model showed that the VAS-GH improved during disease course independent of a change in DAS28. Analyses on the other outcome parameters showed similar results. Patients' perception of health can be different with equal disease activity, depending on the moment in the disease course. Furthermore, our results indicate that self-reported measures on functionality, disease activity, and general health cannot substitute for objective measures of disease activity in RA in longitudinal studies; subsequently, both need to be measured.

  3. DAS performance analysis

    SciTech Connect

    Bates, G.; Bodine, S.; Carroll, T.; Keller, M.

    1984-02-01

    This report begins with an overview of the Data Acquisition System (DAS), which supports several of PPPL's experimental devices. Performance measurements which were taken on DAS and the tools used to make them are then described.

  4. DAS User Manual

    NASA Astrophysics Data System (ADS)

    Østensen, Roy

    2008-10-01

    The HELAS Database for AsteroSeismology (DAS) is one of the deliverables of the Work Package NA5: Asteroseismology of the European Coordination Action in Helio- and Asteroseismology (HELAS). The DAS aims to provide easy access to publicly available asteroseismological timeseries data, both photometric and spectroscopic. In particular, the DAS and the HELAS software package FAMIAS are ideally suited to train Master and PhD students in asteroseismic data analysis and to build longterm datasets. The number of stars in the system is still limited and reflects the willingness of data owners to provide their data after publication. Work continues to populate the database with contributions from the community, and at present the number of stars in the database is 82

  5. Das DNA-Puzzle

    NASA Astrophysics Data System (ADS)

    Kirchner, Stefan

    Im Jahre 1953 wurde von James Watson und Francis Crick erstmalig der strukturelle Aufbau der sogenannten DNA (Desoxyribonukleinsäure) beschrieben, welche das Erbgut jedes Lebewesens enthält. Der wesentliche Teil des Erbguts wird dabei durch eine sehr lange Folge der vier Basen Adenin (A), Cytosin (C), Guanin (G) und Thymin (T) codiert. Seit einigen Jahren ist es möglich, die Folge der vier Basen zu einer gegebenen DNA zu bestimmen. Biologen bezeichnen diesen Vorgang als Sequenzierung.

  6. Das Zwillingsparadoxon: Gedankenexperimente

    NASA Astrophysics Data System (ADS)

    Genz, Henning

    2002-09-01

    Das vermeintliche Zwillingsparadoxon ist ein Gedankenexperiment mit einem Zwillingspaar: Ein Zwilling reist mit hoher Geschwindigkeit von der Erde weg und kehrt nach einiger Zeit zurück, sein Partner bleibt auf der Erde. Dabei altert der Reisende langsamer als der Ruhende - warum nicht umgekehrt? Ein Vergleich von Uhren, die sich mit konstanter Geschwindigkeit bewegen, zeigt: Der Effekt hängt nur von Geschwindigkeiten und nicht von Beschleunigungen ab. Er beruht also allein auf der Speziellen Relativitätstheorie. Tauschen die Zwillinge in regelmäßigen Abständen Lichtsignale aus, können sie ihr asymmetrisches Altern sogar in Zeitschritten mitprotokollieren.

  7. Das Allgemeine Statistische Archiv

    NASA Astrophysics Data System (ADS)

    Rinne, Horst

    Das Allgemeine Statistische Archiv1, nachfolgend kurz Archiv genannt, ist die älteste, ausschließlich der Statistik gewidmete deutschsprachige wissenschaftliche Fachzeitschrift. Sie ist gut zwanzig Jahre älter als die Deutsche Statistische Gesellschaft, zu deren Publikationsorgan sie mit der Gründung der Gesellschaft im Jahre 1911 wurde. Zeitschrift und Gesellschaft blicken auf eine sehr wechselvolle, aber erfolgreiche gemeinsame Geschichte zurück. Die wissenschaftliche Arbeit der Gesellschaft ist im Archiv und seinen Sonderheften für nachfolgende Generationen dokumentiert.

  8. Connecting the Dots in DAS

    ERIC Educational Resources Information Center

    Ford, Tracy

    2012-01-01

    Many institutions implement a distributed antenna system (DAS) as part of a holistic approach to providing better wireless coverage and capacity on campus. A DAS provides wireless service within a particular area or structure via a network of separate antenna nodes that are connected to a common source through fiber or coaxial cable. Because DAS…

  9. Connecting the Dots in DAS

    ERIC Educational Resources Information Center

    Ford, Tracy

    2012-01-01

    Many institutions implement a distributed antenna system (DAS) as part of a holistic approach to providing better wireless coverage and capacity on campus. A DAS provides wireless service within a particular area or structure via a network of separate antenna nodes that are connected to a common source through fiber or coaxial cable. Because DAS…

  10. Token-to-Token Variability in Developmental Apraxia of Speech: Three Longitudinal Case Studies

    ERIC Educational Resources Information Center

    Marquardt, Thomas P.; Jacks, Adam; Davis, Barbara L.

    2004-01-01

    Variability in the speech production patterns of children with developmental apraxia of speech (DAS) was investigated in a three-year longitudinal study of three children with DAS. A metric was developed to measure token-to-token variability in repeated word productions from connected speech samples. Results suggest that high levels of total token…

  11. MyDas, an extensible Java DAS server.

    PubMed

    Salazar, Gustavo A; García, Leyla J; Jones, Philip; Jimenez, Rafael C; Quinn, Antony F; Jenkinson, Andrew M; Mulder, Nicola; Martin, Maria; Hunter, Sarah; Hermjakob, Henning

    2012-01-01

    A large number of diverse, complex, and distributed data resources are currently available in the Bioinformatics domain. The pace of discovery and the diversity of information means that centralised reference databases like UniProt and Ensembl cannot integrate all potentially relevant information sources. From a user perspective however, centralised access to all relevant information concerning a specific query is essential. The Distributed Annotation System (DAS) defines a communication protocol to exchange annotations on genomic and protein sequences; this standardisation enables clients to retrieve data from a myriad of sources, thus offering centralised access to end-users.We introduce MyDas, a web server that facilitates the publishing of biological annotations according to the DAS specification. It deals with the common functionality requirements of making data available, while also providing an extension mechanism in order to implement the specifics of data store interaction. MyDas allows the user to define where the required information is located along with its structure, and is then responsible for the communication protocol details.

  12. Comparison of the DAS28-CRP and DAS28-ESR in patients with rheumatoid arthritis.

    PubMed

    Sengul, Ilker; Akcay-Yalbuzdag, Seniz; Ince, Bugra; Goksel-Karatepe, Altinay; Kaya, Taciser

    2015-07-01

    To compare the Disease Activity Score with 28 joint (DAS28) using erythrocyte sedimentation rate (ESR) (DAS28-ESR) and DAS28 using C-reactive protein (CRP) (DAS28-CRP) with thresholds validated for DAS28-ESR in Turkish patients with rheumatoid arthritis. The DAS28 data of 112 patients with rheumatoid arthritis followed in a local outpatient clinic were used. First, the correlation between DAS28-CRP and DAS28-ESR and the correlation between their unique components ([0.36 × In (CRP + 1) + 0.96] and [0.70 × In (ESR)]) were analyzed. Second, a Bland-Altman plot was constructed for the evaluation of the level of agreement between DAS28-CRP and DAS28-ESR. Lastly, the agreement between these two methods was analyzed by κ coefficient. Although there was a strong correlation between DAS28-CRP and DAS28-ESR, the correlation between their unique components was fair. Although more than 95% of the point data fall between the upper and lower bounds of the limit of agreement, the percentage error (46%) was higher than the acceptable proportion of 30%. The κ coefficient of agreement between DAS28- ESR and DAS28-CRP with validated thresholds for DAS28-ESR was 0.42, which was close to the lower boundary for moderate agreement. The results of this study demonstrated that there is discordance between DAS28-ESR and DAS28-CRP with the validated thresholds for DAS28-ESR. Using the DAS28-CRP with threshold values validated for DAS28-ESR may lead to errors in the determination of disease activity and therefore may lead to errors in the management of patients with rheumatoid arthritis. © 2015 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.

  13. Longitudinal impedance of RHIC

    SciTech Connect

    Blaskiewicz, M.; Brennan, J. M.; Mernick, K.

    2015-05-03

    The longitudinal impedance of the two RHIC rings has been measured using the effect of potential well distortion on longitudinal Schottky measurements. For the blue RHIC ring Im(Z/n) = 1.5±0.2Ω. For the yellow ring Im(Z/n) = 5.4±1Ω.

  14. Longitudinal Multistage Testing

    ERIC Educational Resources Information Center

    Pohl, Steffi

    2013-01-01

    This article introduces longitudinal multistage testing (lMST), a special form of multistage testing (MST), as a method for adaptive testing in longitudinal large-scale studies. In lMST designs, test forms of different difficulty levels are used, whereas the values on a pretest determine the routing to these test forms. Since lMST allows for…

  15. Longitudinal Stability Calculations

    SciTech Connect

    Blaskiewicz,M.

    2009-01-02

    Coupled bunch longitudinal stability in the presence of high frequency impedances is considered. A frequency domain technique is developed and compared with simulations. The frequency domain technique allows for absolute stability tests and is applied to the problem of longitudinal stability in RHIC with the new 56 MHz RF system.

  16. Longitudinal Magnification Drawing Mistake

    NASA Astrophysics Data System (ADS)

    Rabal, Héctor; Cap, Nelly; Trivi, Marcelo

    2004-01-01

    Lateral magnification in image formation by positive lenses, mirrors, and dioptrics is usually appropriately developed in most optics textbooks.1-9 However, the image of a three-dimensional object occupies a three-dimensional region of space. The optical system affects both the transverse and the longitudinal dimensions of the object and, in general, does it in different ways. The magnification in the direction of the optical axis (the longitudinal magnification) is seldom treated. In several texts, the concept of longitudinal magnification is not even considered. Symmetrical objects (such as arrows) are used and their images appear laterally inverted. It is not shown how a longitudinally nonsymmetric object is imaged. One of the few books where this subject is well treated is in the textbook by Hecht.10 We have repeatedly verified in our classes that there is some confusion related to this subject. Students tend to believe that the image is longitudinally symmetric with respect to the lens optic center. Some prestigious texts commit the same mistake. In addition, a very nice optics book,11 a catalogue of optical hardware,12 a worldwide scientific magazine,13 a paper in an optics journal,14 and a Spanish encyclopedia,15 for example, have also been found to contain this error in drawing the image of a three-dimensional object formed by a positive lens. In this paper we suggest that the teaching of longitudinal magnification should be done with some care and we include a figure showing a properly drawn image.

  17. Data Acquisition System(DAS) Sustaining Engineering

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This paper presents general information describing the Data Acquisition System contract, a summary of objectives, tasks performed and completed. The hardware deliverables which are comprised of: 1) Two ground DAS units; 2) Two flight DAS units; 3) Logistic spares; and 4) Shipping containers are described. Also included are the data requirements and scope of the contract.

  18. Longitudinal magnetoresistance of potassium

    NASA Astrophysics Data System (ADS)

    Huberman, M. L.

    1987-06-01

    Recently, Zhu and Overhauser showed that the Hall coefficient of potassium is anisotropic, depending on the angle between the applied magnetic field and the charge-density wave. It follows that the Hall coefficient of a polydomain sample is inhomogeneous. By means of effective-medium theory, the magnetoresistance of a domain structure has been evaluated. It is shown that both the longitudinal and transverse magnetoresistance increase with increasing field. The Kohler slope depends on the domain distribution. For a random distribution, the longitudinal and transverse Kohler slopes are about (1/2)% and 1(1/2)%, respectively.

  19. Longitudinal Functional Data Analysis.

    PubMed

    Park, So Young; Staicu, Ana-Maria

    We consider dependent functional data that are correlated because of a longitudinal-based design: each subject is observed at repeated times and at each time a functional observation (curve) is recorded. We propose a novel parsimonious modeling framework for repeatedly observed functional observations that allows to extract low dimensional features. The proposed methodology accounts for the longitudinal design, is designed to study the dynamic behavior of the underlying process, allows prediction of full future trajectory, and is computationally fast. Theoretical properties of this framework are studied and numerical investigations confirm excellent behavior in finite samples. The proposed method is motivated by and applied to a diffusion tensor imaging study of multiple sclerosis.

  20. GATB LONGITUDINAL MATURATION STUDY.

    ERIC Educational Resources Information Center

    DROEGE, ROBERT C.

    THIS ARTICLE DESCRIBES RESULTS OF THE FIRST IN A SERIES OF THREE LARGE-SCALE LONGITUDINAL STUDIES CONDUCTED BY THE U.S. EMPLOYMENT SERVICE TO INCREASE THE USEFULNESS OF THE GENERAL APTITUDE TEST BATTERY (GATB) FOR COUNSELING HIGH SCHOOL STUDENTS. THE FINAL SAMPLE CONSISTED OF 26,708 HIGH SCHOOL STUDENTS. ALL WERE TESTED WITH THE GATB IN 1958, AND…

  1. Longitudinal discharge laser baffles

    DOEpatents

    Warner, B.E.; Ault, E.R.

    1994-06-07

    The IR baffles placed between the window and the electrode of a longitudinal discharge laser improve laser performance by intercepting off-axis IR radiation from the laser and in doing so reduce window heating and subsequent optical distortion of the laser beam. 1 fig.

  2. Longitudinal discharge laser electrodes

    DOEpatents

    Warner, B.E.; Miller, J.L.; Ault, E.R.

    1994-08-23

    The improved longitudinal discharge laser electrode with IR baffle includes an electrode made up of washers spaced along the laser axis in order to form inter-washer spaces for hollow cathode discharge to take place and for IR radiation to be trapped. Additional IR baffles can be placed between the electrode ann the window. 2 figs.

  3. Longitudinal discharge laser baffles

    DOEpatents

    Warner, Bruce E.; Ault, Earl R.

    1994-01-01

    The IR baffles placed between the window and the electrode of a longitudinal discharge laser improve laser performance by intercepting off-axis IR radiation from the laser and in doing so reduce window heating and subsequent optical distortion of the laser beam.

  4. Longitudinal discharge laser electrodes

    DOEpatents

    Warner, Bruce E.; Miller, John L.; Ault, Earl R.

    1994-01-01

    The improved longitudinal discharge laser electrode with IR baffle includes an electrode made up of washers spaced along the laser axis in order to form inter-washer spaces for hollow cathode discharge to take place and for IR radiation to be trapped. Additional IR baffles can be placed between the electrode ann the window.

  5. Longitudinally graded optical fibers

    NASA Astrophysics Data System (ADS)

    Evert, A.; James, A.; Hawkins, T.; Foy, P.; Dong, L.; Stolen, R.; Ballato, J.; Dragic, P.; Rice, R.

    2013-03-01

    Described herein, for the first time to the best of our knowledge, are results on optical fibers possessing significant compositional gradations along its length due to longitudinal control of the core glass composition. More specifically, MCVD-derived germanosilicate fibers were fabricated that exhibited a gradient of up to about 0.55 weight % GeO2 per meter. These gradients are about 1900 times greater than previously reported fibers possessing longitudinal changes in composition. The refractive index difference is shown to change by about 0.001, representing a numerical aperture change of about 10%, over a fiber length of less than 20 m. The lowest attenuation measured from the present longitudinally-graded fiber (LGF) was 82 dB/km at a wavelength of 1550 nm, though this is shown to result from extrinsic process-induced factors and could be reduced with further optimization. The stimulated Brillouin scattering (SBS) spectrum from the LGF exhibited a 4.4 dB increase in the spectral width, and thus reduction in Brillouin gain, relative to a standard commercial single mode fiber, over a fiber length of only 17 m. The method employed is very straight-forward and provides for a wide variety of longitudinal refractive index and acoustic velocity profiles, as well as core shapes, which could be especially valuable for SBS suppression in high-energy laser systems. Next generation analogs, with longitudinally-graded compositional profiles that are very reasonable to fabricate, are shown computationally to be more effective at suppressing SBS than present alternatives, such as externally-applied temperature or strain gradients.

  6. Experimental Demonstration of Longitudinal Magnification

    ERIC Educational Resources Information Center

    Razpet, Nada; Susman, Katarina; Cepic, Mojca

    2009-01-01

    We describe an experiment which enables the observation of longitudinal magnification for the real image of a three-dimensional (3D) object formed by a converging lens. The experiment also shows the absence of longitudinal inversion. Possible reasons for misconceptions with respect to real images and longitudinal inversions are discussed and a…

  7. Experimental Demonstration of Longitudinal Magnification

    ERIC Educational Resources Information Center

    Razpet, Nada; Susman, Katarina; Cepic, Mojca

    2009-01-01

    We describe an experiment which enables the observation of longitudinal magnification for the real image of a three-dimensional (3D) object formed by a converging lens. The experiment also shows the absence of longitudinal inversion. Possible reasons for misconceptions with respect to real images and longitudinal inversions are discussed and a…

  8. DAS28-CRP and DAS28-ESR cut-offs for high disease activity in rheumatoid arthritis are not interchangeable

    PubMed Central

    Fleischmann, Roy M; van der Heijde, Désirée; Gardiner, Philip V; Szumski, Annette; Marshall, Lisa; Bananis, Eustratios

    2017-01-01

    Background In most patients with rheumatoid arthritis (RA), Disease Activity Score 28-joint count C reactive protein (DAS28-CRP) is lower than DAS28 erythrocyte sedimentation rate (DAS28-ESR), suggesting that use of the DAS28-ESR cut-off to assess high disease activity (HDA) with DAS28-CRP may underestimate the number of patients with HDA. We determined the DAS28-CRP value corresponding to the validated DAS28-ESR cut-off for HDA. Methods Baseline data were pooled from 2 clinical studies evaluating etanercept (ETN) plus methotrexate (MTX) or MTX in early RA; DAS28-CRP and DAS28-ESR were obtained, allowing the determination of the DAS28-CRP HDA value best corresponding to the DAS28-ESR cut-off of >5.1. Results At baseline, as expected, fewer patients had HDA by DAS28-CRP than DAS28-ESR; DAS28-CRP>5.1 and DAS28-ESR>5.1 had only modest agreement (κ coefficients 0.45–0.54). Mean DAS28-CRP and DAS28-ESR were 5.7 and 6.2, respectively, in the ETN+MTX group (n=571), and 6.0 and 6.5 in the MTX group (n=262). A DAS28-CRP cut-off of 4.6 corresponded to a DAS28-ESR cut-off of 5.1. Conclusions We have shown that a DAS28-CRP of 4.6 corresponds to 5.1 for DAS28-ESR. Since this is substantially lower than the DAS28-ESR cut-off of 5.1, using 5.1 as the cut-off for DAS28-CRP underestimates disease activity in RA. Trial registration number NCT00195494; NCT00913458. PMID:28255449

  9. Longitudinally Graded Optical Fibers

    NASA Astrophysics Data System (ADS)

    Evert, Alexander George

    Described herein, for the first time to the best of our knowledge, are optical fibers possessing significant compositional gradations along their length due to longitudinal control of the core glass composition. More specifically, MCVD-derived germanosilicate fibers were fabricated that exhibited a gradient of up to about 0.55 weight percent GeO2 per meter. These gradients are about 1900 times greater than previously reported for fibers possessing longitudinal changes in composition. The refractive index difference is shown to change by about 0.001, representing a numerical aperture change of about 10%, over a fiber length of less than 20 m. The lowest attenuation measured from the present longitudinally-graded fiber (LGF) was 82 dB/km at a wavelength of 1550 nm, though this is shown to result from extrinsic process-induced factors and could be reduced with further optimization. The stimulated Brillouin scattering (SBS) spectrum from the LGF exhibited a 4.4 dB increase in the spectral width, and thus reduction in Brillouin gain, relative to a standard commercial single mode fiber, over a fiber length of only 17 m. Fibers with longitudinally uniform (i.e., not gradient) refractive index profiles but differing chemical compositions among various core layers were also fabricated to determine acoustic effects of the core slug method. The refractive index of the resulting preform varies by about +/- 0.00013 from the average. Upon core drilling, it was found that the core slugs had been drilled off-center from the parent preform, resulting in semi-circular core cross sections that were unable to guide light. As a result, optical analysis could not be conducted. Chemical composition data was obtained, however, and is described herein. A third fiber produced was actively doped with ytterbium (Yb3 ) and fabricated similarly to the previous fibers. The preforms were doped via the solution doping method with a solution of 0.015 M Yb 3 derived from ytterbium chloride

  10. Muon cooling: longitudinal compression.

    PubMed

    Bao, Yu; Antognini, Aldo; Bertl, Wilhelm; Hildebrandt, Malte; Khaw, Kim Siang; Kirch, Klaus; Papa, Angela; Petitjean, Claude; Piegsa, Florian M; Ritt, Stefan; Sedlak, Kamil; Stoykov, Alexey; Taqqu, David

    2014-06-06

    A 10  MeV/c positive muon beam was stopped in helium gas of a few mbar in a magnetic field of 5 T. The muon "swarm" has been efficiently compressed from a length of 16 cm down to a few mm along the magnetic field axis (longitudinal compression) using electrostatic fields. The simulation reproduces the low energy interactions of slow muons in helium gas. Phase space compression occurs on the order of microseconds, compatible with the muon lifetime of 2  μs. This paves the way for the preparation of a high-quality low-energy muon beam, with an increase in phase space density relative to a standard surface muon beam of 10^{7}. The achievable phase space compression by using only the longitudinal stage presented here is of the order of 10^{4}.

  11. Dasty3, a WEB framework for DAS

    PubMed Central

    Villaveces, Jose M.; Jimenez, Rafael C.; Garcia, Leyla J.; Salazar, Gustavo A.; Gel, Bernat; Mulder, Nicola; Martin, Maria; Garcia, Alexander; Hermjakob, Henning

    2011-01-01

    Motivation: Dasty3 is a highly interactive and extensible Web-based framework. It provides a rich Application Programming Interface upon which it is possible to develop specialized clients capable of retrieving information from DAS sources as well as from data providers not using the DAS protocol. Dasty3 provides significant improvements on previous Web-based frameworks and is implemented using the 1.6 DAS specification. Availability: Dasty3 is an open-source tool freely available at http://www.ebi.ac.uk/dasty/ under the terms of the GNU General public license. Source and documentation can be found at http://code.google.com/p/dasty/. Contact: hhe@ebi.ac.uk PMID:21798964

  12. Análise da cinemática interna das regiões HII gigantes e das galáxias HII

    NASA Astrophysics Data System (ADS)

    Plana, H.; Telles, E.; Maíz-Apellániz, J.

    2003-08-01

    Neste trabalho nós mostramos os primeiros resultados de um estudo sobre a cinemática das Regiões HII Gigantes (GHIIRs) em galáxias próximas. Essas regiões HII têm um diâmetro médio entre 100 pc e 1000 pc e uma taxa de formação estelar de 106 M¤ / ano sendo equivalente à observada em galáxias de tipo tardio correspondendo a uma taxa de formação estelar por unidade de volume uma ordem de magnitude maior que a observada em regiões HII normais. Usando espectros de fenda longas em várias posições, nós construímos mapas de velocidades, de dispersão e de intensidade para várias linhas de emissão como Ha, Hb, [NII]6584 Å, [OIII]5007 Å e o doublet de [SII], para cinco regiões gigantes: NGC 2403 II e IV, NGC 595, NGC 5461, NGC 5471, NGC 5455. O estudo da cinemática (mapas de velocidades e da dispersão) mostrou, por exemplo, a presença de cascas em expansão em NGC 595 ou perfis de emissão com várias componentes em NGC 5461. Os perfis de emissão também mostram velocidades supersônicas. Os resultados são discutidos em comparação com os de estudos anteriores realizados.

  13. GHRSST-14 DAS-TAG Report

    NASA Technical Reports Server (NTRS)

    Armstrong, Edward; Piolle, Jean Francois

    2013-01-01

    The DAS-TAG provides the informatics and data management expertise in emerging information technologies for the GHRSST community. It provides expertise in data and metadata formats and standards, fosters improvements for GHRSST data curation, experiments with new data processing paradigms, and evaluates services and tools for data usage. It provides a forum for producer and distributor data management issues and coordination.

  14. Physik gestern und heute Das Eiskalorimeter

    NASA Astrophysics Data System (ADS)

    Heering, P.

    2003-07-01

    Kalorimetrische Messungen gehören heute zum experimentellen Standardrepertoire im Bereich der Thermodynamik und der physikalischen Chemie. Das erste Gerät für derartige Messungen entwickelten Ende des 18. Jahrhunderts die französischen Wissenschaftler Antoine Laurent Lavoisier und Pierre Simon de Laplace.

  15. GHRSST-14 DAS-TAG Report

    NASA Technical Reports Server (NTRS)

    Armstrong, Edward; Piolle, Jean Francois

    2013-01-01

    The DAS-TAG provides the informatics and data management expertise in emerging information technologies for the GHRSST community. It provides expertise in data and metadata formats and standards, fosters improvements for GHRSST data curation, experiments with new data processing paradigms, and evaluates services and tools for data usage. It provides a forum for producer and distributor data management issues and coordination.

  16. A Large, Longitudinal Dune

    NASA Image and Video Library

    2015-02-11

    Taken in late southern spring and when Mars is near perihelion (closest distance to the Sun), this image shows the effects of dry ice sublimation on a longitudinal dune in the far Southern hemisphere. The bright patches on the dune are still covered in frost, and the dark regions are frost-free. Longitudinal dunes form when the wind switches between two common directions*. Based on the direction of this dune's long crest and the orientation of the smaller ripples, it appears the wind blows from the east and from the northwest. However, it would require taking multiple HiRISE images of this location over time and noticing movement before we could say this definitively. The broad base of this dune may indicate that dune sand has spilled out from areas once covered in ice. During the next Martian Southern hemisphere winter (about half a Mars year or one Earth year from when this image was taken), this dune will again be covered in frost and possibly solid carbon dioxide ice, unable to blow in the wind until the volatiles begin to sublimate in the spring. *These are ripples indicating a wind out of the north/northwest. The scene is 250 m across. http://photojournal.jpl.nasa.gov/catalog/PIA19293

  17. Modeling nonstationary longitudinal data.

    PubMed

    Núñez-Antón, V; Zimmerman, D L

    2000-09-01

    An important theme of longitudinal data analysis in the past two decades has been the development and use of explicit parametric models for the data's variance-covariance structure. A variety of these models have been proposed, of which most are second-order stationary. A few are flexible enough to accommodate nonstationarity, i.e., nonconstant variances and/or correlations that are not a function solely of elapsed time between measurements. We review five nonstationary models that we regard as most useful: (1) the unstructured covariance model, (2) unstructured antedependence models, (3) structured antedependence models, (4) autoregressive integrated moving average and similar models, and (5) random coefficients models. We evaluate the relative strengths and limitations of each model, emphasizing when it is inappropriate or unlikely to be useful. We present three examples to illustrate the fitting and comparison of the models and to demonstrate that nonstationary longitudinal data can be modeled effectively and, in some cases, quite parsimoniously. In these examples, the antedependence models generally prove to be superior and the random coefficients models prove to be inferior. We conclude that antedependence models should be given much greater consideration than they have historically received.

  18. Detecting changes following the provision of assistive devices: utility of the WHO-DAS II.

    PubMed

    Raggi, Alberto; Albanesi, Francesca; Gatti, Valeria; Andrich, Renzo; Leonardi, Matilde

    2010-12-01

    The World Health Organization Disability Assessment Schedule II (WHO-DAS II) is a non-disease-specific International Classification of Functioning, Disability, and Health-based disability assessment instrument developed to measure activity limitations and restrictions to participation. The aim of this pilot study is to evaluate WHO-DAS II responsiveness in detecting short-time changes following the provision of an Assistive Technology,which is important to define its utility in performing daily activities. Adult inpatients with a diagnosis of Disease of the Nervous System (included in Chapter VI of the ICD-10),who were prescribed an Assistive Technology to be used in the household settings, were enrolled. The WHO-DAS II was administered in individual interview at baseline and at a 2 months follow-up: in this period patients were transitioning from the hospital to home. Changes in disability profiles were detected by calculating the effect size (ES) for each WHO-DAS II domain. Ten patients with different neurological diseases were enrolled. Few longitudinal changes in disability level are reported: mild improvement is observed in the household activities (ES0.28), whereas mild worsening is reported in self-care and participation in society domains (ES – 0.27 and – 0.26,respectively). Our study shows that the WHO-DAS II is responsive in detecting domain-specific changes over a short-term period and provides preliminary encouraging evidence for the utility of its utilization in clinical settings.However, changes in setting between baseline and follow up could have an impact on the findings and interpretation of this study.

  19. Longitudinal Stern-Gerlach

    NASA Astrophysics Data System (ADS)

    Higinbotham, Douglas

    2006-11-01

    In 1922 Otto Stern and Walther Gerlach split a beam of silver atoms using a transverse gradient field. This experiment, which lead to the understanding that electrons have intrinsic spin, oddly enough does not work for free electrons due to the interplay between the Lorentz force and Heisenberg uncertainly principle. Recent calculations, Phys. Rev. Lett. 79 (1997) 4517 and Phys. Rev. Lett. 86 (2001) 4508, have shown that a dismissed idea of L. Brillouin from 1928 to use a longitudinal gradient field to minimize the effect of the Lorentz force may in fact be possible. The history of the Stern-Gerlach device will be presented along with the revived ideas for separating a beam of free electrons into its two spin states.

  20. Digital Longitudinal Tomosynthesis

    NASA Astrophysics Data System (ADS)

    Rimkus, Daniel Steven

    1985-12-01

    The purpose of this dissertation was to investigate the clinical utility of digital longitudinal tomosynthesis in radiology. By acquiring a finite group of digital images during a longitudinal tomographic exposure, and processing these images, tomographic planes, other than the fulcrum plane, can be reconstructed. This process is now termed "tomosynthesis". A prototype system utilizing this technique was developed. Both phantom and patient studies were done with this system. The phantom studies were evaluated by subjective, visual criterion and by quantitative analysis of edge sharpness and noise in the reconstructions. Two groups of patients and one volunteer were studied. The first patient group consisted of 8 patients undergoing intravenous urography (IVU). These patients had digital tomography and film tomography of the abdomen. The second patient group consisted of 4 patients with lung cancer admitted to the hospital for laser resection of endobronchial tumor. These patients had mediastinal digital tomograms to evaluate the trachea and mainstem bronchi. The knee of one volunteer was imaged by film tomography and digital tomography. The results of the phantom studies showed that the digital reconstructions accurately produced images of the desired planes. The edge sharpness of the reconstructions approached that of the acquired images. Adequate reconstructions were achieved with as few as 5 images acquired during the exposure, with the quality of the reconstructions improving as the number of images acquired increased. The IVU patients' digital studies had less contrast and spatial resolution than the film tomograms. The single renal lesion visible on the film tomograms was also visible in the digital images. The digital mediastinal studies were felt by several radiologists to be superior to a standard chest xray in evaluating the airways. The digital images of the volunteer's knee showed many of the same anatomic features as the film tomogram, but the digital

  1. Longitudinal space charge amplifier

    NASA Astrophysics Data System (ADS)

    Schneidmiller, E. A.; Yurkov, M. V.

    2013-05-01

    Longitudinal space charge (LSC) driven microbunching instability in electron beam formation systems of X-ray FELs is a recently discovered effect hampering beam instrumentation and FEL operation. The instability was observed in different facilities in infrared and visible wavelength ranges. In this paper we propose to use such an instability for generation of vacuum ultraviolet (VUV) and X-ray radiation. A typical longitudinal space charge amplifier (LSCA) consists of few amplification cascades (drift space plus chicane) with a short undulator behind the last cascade. If the amplifier starts up from the shot noise, the amplified density modulation has a wide band, on the order of unity. The bandwidth of the radiation within the central cone is given by inverse number of undulator periods. A wavelength compression could be an attractive option for LSCA since the process is broadband, and a high compression stability is not required. LSCA can be used as a cheap addition to the existing or planned short-wavelength FELs. In particular, it can produce the second color for a pump-probe experiment. It is also possible to generate attosecond pulses in the VUV and X-ray regimes. Some user experiments can profit from a relatively large bandwidth of the radiation, and this is easy to obtain in LSCA scheme. Finally, since the amplification mechanism is broadband and robust, LSCA can be an interesting alternative to self-amplified spontaneous emission free electron laser (SASE FEL) in the case of using laser-plasma accelerators as drivers of light sources.

  2. Moisture Forecast Bias Correction in GEOS DAS

    NASA Technical Reports Server (NTRS)

    Dee, D.

    1999-01-01

    Data assimilation methods rely on numerous assumptions about the errors involved in measuring and forecasting atmospheric fields. One of the more disturbing of these is that short-term model forecasts are assumed to be unbiased. In case of atmospheric moisture, for example, observational evidence shows that the systematic component of errors in forecasts and analyses is often of the same order of magnitude as the random component. we have implemented a sequential algorithm for estimating forecast moisture bias from rawinsonde data in the Goddard Earth Observing System Data Assimilation System (GEOS DAS). The algorithm is designed to remove the systematic component of analysis errors and can be easily incorporated in an existing statistical data assimilation system. We will present results of initial experiments that show a significant reduction of bias in the GEOS DAS moisture analyses.

  3. The impact of asthma in Brazil: a longitudinal analysis of data from a Brazilian national database system.

    PubMed

    Cardoso, Thiago de Araujo; Roncada, Cristian; Silva, Emerson Rodrigues da; Pinto, Leonardo Araujo; Jones, Marcus Herbert; Stein, Renato Tetelbon; Pitrez, Paulo Márcio

    2017-01-01

    To present official longitudinal data on the impact of asthma in Brazil between 2008 and 2013. This was a descriptive study of data collected between 2008 and 2013 from an official Brazilian national database, including data on asthma-related number of hospitalizations, mortality, and hospitalization costs. A geographical subanalysis was also performed. In 2013, 2,047 people died from asthma in Brazil (5 deaths/day), with more than 120,000 asthma-related hospitalizations. During the whole study period, the absolute number of asthma-related deaths and of hospitalizations decreased by 10% and 36%, respectively. However, the in-hospital mortality rate increased by approximately 25% in that period. The geographic subanalysis showed that the northern/northeastern and southeastern regions had the highest asthma-related hospitalization and in-hospital mortality rates, respectively. An analysis of the states representative of the regions of Brazil revealed discrepancies between the numbers of asthma-related hospitalizations and asthma-related in-hospital mortality rates. During the study period, the cost of asthma-related hospitalizations to the public health care system was US$ 170 million. Although the numbers of asthma-related deaths and hospital admissions in Brazil have been decreasing since 2009, the absolute numbers are still high, resulting in elevated direct and indirect costs for the society. This shows the relevance of the burden of asthma in middle-income countries. Apresentar dados longitudinais oficiais sobre o impacto da asma no Brasil entre 2008 e 2013. Estudo descritivo de dados extraídos de um banco de dados do governo brasileiro entre 2008 e 2013, no qual foram analisados as hospitalizações e óbitos por asma, bem como o custo das hospitalizações. Foi também realizada uma subanálise geográfica. Em 2013, 2.047 pessoas morreram de asma no Brasil (5 óbitos/dia), com mais de 120.000 hospitalizações por asma. Durante o período de estudo, o n

  4. Estudo comparativo entre estrelas centrais de nebulosas planetárias deficientes em hidrogênio

    NASA Astrophysics Data System (ADS)

    Marcolino, W. L. F.; de Araújo, F. X.

    2003-08-01

    Apresentamos neste trabalho o resultado de um estudo das principais características espectrais das estrelas centrais de nebulosas planetárias (ECNP) deficientes em hidrogênio. A origem e a evolução dessas estrelas ainda constitui um problema em aberto na evolução estelar. Geralmente esses objetos são divididos em [WCE], [WCL] e [WELS]. Os tipos [WCE] e [WCL] apresentam um espectro típico de uma estrela Wolf-Rayet carbonada de população I e as [WELS] apresentam linhas fracas de carbono e oxigênio em emissão. Existem evidências que apontam a seguinte sequência evolutiva : [WCL] = > [WCE] = > [WELS] = > PG 1159 (pré anã-branca). No entanto, tal cenário apresenta falhas como por exemplo a falta de ECNP entre os tipos [WCL] e [WCE]. Baseados em uma amostra de 24 objetos obtida no telescópio de 1.52m em La Silla, Chile (acordo ESO/ON), ao longo do ano 2000, apresentamos os resultados da comparação das larguras equivalentes de diversas linhas relevantes entre os tipos [WCL], [WCE] e [WELS]. Verificamos que nossos dados estão de acordo com a sequência evolutiva. Baseado nas linhas de C IV, conseguimos dividir pela primeira vez as [WELS] em dois grupos principais. Além disso, os dados reforçam a afirmação de que as [WCE] são as estrelas que possuem a maior temperatura entre as ECNP deficientes em hidrogênio. Discutimos ainda, a escassez de dados disponíveis na literatura e a necessidade da obtenção de parametros físicos para estes objetos.

  5. Current status of longitudinal stability

    NASA Technical Reports Server (NTRS)

    Donlan, Charles J

    1948-01-01

    The problems of static and dynamic longitudinal stability both at high speeds and at low speeds are discussed and data are presented which indicate recent progress made in the solution of these problems.

  6. PoroTomo: DAS Vibroseis Data

    DOE Data Explorer

    Kurt Feigl

    2016-03-25

    The submitted data correspond to the monitored vibrations caused by a vibroseis seismically exciting the ground in the vertical direction and captured by the DAS horizontal and vertical arrays during the PoroTomo Experiment. The data also include a file with the acceleration record at the Vibroseis. Vibroseis Sweep Details: Sweep on location T84 Stage 4 (Mode P 60 s long record ) Time: 2016-03-25 14:01:15 (UTC) Location: 39.80476089N, -119.0027625W Elevation: 1272.0M (on ground surface at the site) Sweep length: 20 seconds Frequencies: 5 Hz to 20 Hz

  7. Das CARNOTsche Paradigma und seine erkenntnistheoretischen Implikationen

    NASA Astrophysics Data System (ADS)

    Schöpf, Hans-Georg

    Der vorliegende historisch-kritische Essay führt die Eigentümlichkeiten der klassischen phänomenologischen Thermodynamik auf das von CARNOT geschaffene Paradigma zurück und greift einige damit zusammenhängende Fragen auf.Translated AbstractCARNOT's Paradigm and its Epistemological ImplicationsThe present historic-critical essay traces the pecularities of classical phenomenological thermodynamics back to the paradigm, created by CARNOT, and takes up some questions to which this paradigm gives rise.

  8. Histochemistry of Centroorhynchus falconis (Das, 1950).

    PubMed

    Rengaraju, V; Das, E N

    1976-01-01

    With a view to augment the understanding of the animal mucosubstances in general and Acanthocephalan mucosubstances in particular, Acanthocephalan worms of (Centrorhynchus falconis, Das, 1950) were investigated histochemically by employing recent techniques. Variations in the intensity of histochemical reactions in different tissues revealed a heterogenous distribution of mucosubstances. The cuticle contained a mixture of periodate reactive neutral mucosubstances and sulfomucins, whereas the subcuticle contained only glycogen. Retractor muscles contained glycogen together with some acidic mucosubstances which exhibited alcianophilia only at high pH. Cement glands elaborated a mixture of glycogen and galactogen. Histochemical methods revealed two types of acanthors: Some contained only glycogen, whereas others contained glycogen and galactogen.

  9. PoroTomo Project - Subatask 6.2: Deploy and Operate DAS and DTS arrays - DAS Earthquake Data

    DOE Data Explorer

    Kurt Feigl

    2016-03-21

    The submitted data correspond to the vibration caused by a 3.4 M earthquake and captured by the DAS horizontal and vertical arrays during the PoroTomo Experiment. Earthquake information : M 4.3 - 23km ESE of Hawthorne, Nevada Time: 2016-03-21 07:37:10 (UTC) Location: 38.479°N 118.366°W Depth: 9.9 km Files for horizontal DAS array (each file is 30 s long and contain 8700 channels): PoroTomo_iDAS16043_160321073721.sgy PoroTomo_iDAS16043_160321073751.sgy Files for vertical DAS Array (each file is 30 s long and contain 380 channels): PoroTomo_iDAS025_160321073717.sgy PoroTomo_iDAS025_160321073747.sgy

  10. Longitudinal dynamics in storage rings

    SciTech Connect

    Colton, E.P.

    1986-01-01

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

  11. Longitudinal motion in circular accelerators

    SciTech Connect

    Cole, F.T.

    1985-01-01

    A general description is given of the longitudinal motion of an idealized synchronous particle, exactly in step with the radiofrequency field of a circular accelerator, and a domain in phase and energy, called a bucket, around this particle within which particles are focused around the synchronous particle. This general picture is then made more precise and quantitative. The equations of longitudinal motion and their solutions and the resulting motion are discussed, followed by applications and amplication of the theory. 7 refs., 8 figs. (LEW)

  12. Estudo da região HII galática NGC 2579

    NASA Astrophysics Data System (ADS)

    Riffel, R.; Copetti, M. V. F.

    2003-08-01

    Desde a descoberta dos gradientes de abundância química em galáxias espirais, as regiões HII galáticas têm sido intensamente estudadas com o objetivo de determinar a forma do gradiente de abundância química na Via-Láctea. Entretanto, a forma do gradiente galático continua controversa e existem muitas regiões HII que continuam inexploradas. A região HII galática NGC 2579 é um objeto que aparece em imagens Ha, como uma pequena mancha brilhante de aproximadamente 2 segundos de arco de diâmetro a 20 segundos de arco ao leste de RCW 20, sendo NGC 2579 muitas vezes confundida com esta última. Apesar de seu alto brilho superficial, NGC 2579 é um objeto pouco estudado provavelmente por problemas de identificação deste objeto. Como parte de um projeto de reavaliação dos gradientes de abundância química das regiões HII na Via-Láctea, estamos realizando um estudo extensivo das propriedades físicas básicas como temperatura eletrônica, densidade eletrônica e composição química da região HII galática NGC 2579. Analisamos dados espectrofotométricos de fenda longa na faixa de 3700Å a 7750Å obtidos com o telescópio de 1.52 m do ESO, Chile, em 2002. Determinamos a temperatura eletrônica usando a razão entre as linhas do [OIII] (l4959+l5007/l4363) e a densidade eletrônica pela razão entre as linhas do [SII] (l6716/l6731). As abundâncias químicas do O, N, Cl, S, Ne e He foram determinadas. Realizamos um estudo de imagens fotométricas nas bandas UBVRI obtidas em 2000 no observatório astronômico San Pedro Mártir, México, para identificar e classificar as estrelas ionizantes de NGC 2579 e determinar a distância deste objeto.

  13. Hemorrhagic Longitudinally Extensive Transverse Myelitis.

    PubMed

    Wu, Chris Y; Riangwiwat, Tanawan; Nakamoto, Beau K

    2016-01-01

    Longitudinally extensive transverse myelitis (LETM) may be associated with viral triggers, including both infections and vaccinations. We present a case of a healthy immunocompetent 33-year-old woman who developed a hemorrhagic LETM 2 weeks after seasonal influenza vaccination. Hemorrhagic LETM has not to our knowledge been reported after influenza vaccination. It may represent a forme fruste variant of acute hemorrhagic leukoencephalitis.

  14. Longitudinal Studies of Spelling Development.

    ERIC Educational Resources Information Center

    Ellis, Nick

    Noting that proposed models of literacy development suggest that reading and writing mutually influence and grow from each other, this paper summarizes aspects of stage theories of literacy development and an integrative model, and considers how the model fared in empirical longitudinal tests. The paper begins with a summary of the modal aspects…

  15. Students dance longitudinal standing waves

    NASA Astrophysics Data System (ADS)

    Ruiz, Michael J.

    2017-05-01

    A demonstration is presented that involves students dancing longitudinal standing waves. The resulting kinaesthetic experience and visualization both contribute towards an understanding of the natural modes of vibrations in open and closed pipes. A video of this fun classroom activity is provided (http://mjtruiz.com/ped/dance/).

  16. Regression Splines with Longitudinal Data

    USDA-ARS?s Scientific Manuscript database

    In many clinical trial studies, patients are observed and/or measured on multiple occasions. To account for the longitudinal nature of the data, a mixed model analysis implemented using SAS PROC MIXED is commonly used. It is typical to make comparisons between dose or treatment groups, possibly cont...

  17. "Das Konkrete ist das Abstrakte, an das man sich schließlich gewöhnt hat." (Laurent Schwartz) Über den Ablauf des mathematischen Verstehens

    NASA Astrophysics Data System (ADS)

    Lowsky, Martin

    Die im Titel genannte Aussage findet sich in den Lebenserinnerungen von Laurent Schwartz (1915-2002), einem der fruchtbarsten Mathematiker, Mitglied der Gruppe Bourbaki. Im Original lautet die Aussage: "un objet concret est un objet abstrait auquel on a fini par s'habituer." Schwartz erläutert sie am Beispiel des Integrals über {e^{-1/2{x^2}}} , das den Wert Wurzel aus 2π hat und in dem sich also die Zahlen e und π verknüpfen. Was Schwartz aber vor allem ausdrücken will, ist dies: Das mathematische Verständnisd geht langsam vor sich und es bedarf der Anstrengung. "Es ist eine Frage der Zeit und der Energie", sagt Schwartz, und gerade dies mache es so schwer, die höhere Mathematik unter das Volk zu bringen. Das Lernen und Lehren von Mathematik laufe eben mühevoll und langsam ab.

  18. Pedagogical Basis of DAS Formalism in Engineering Education

    ERIC Educational Resources Information Center

    Hiltunen, J.; Heikkinen, E.-P.; Jaako, J.; Ahola, J.

    2011-01-01

    The paper presents a new approach for a bachelor-level curriculum structure in engineering. The approach is called DAS formalism according to its three phases: description, analysis and synthesis. Although developed specifically for process and environmental engineering, DAS formalism has a generic nature and it could also be used in other…

  19. Evidence of Motor Programming Deficits in Children Diagnosed with DAS.

    ERIC Educational Resources Information Center

    Nijland, Lian; Maassen, Ben; van der Meulen, Sjoeke

    2003-01-01

    Five children with developmental apraxia of speech (DAS), 5 controls (ages 5-6), and 6 adults produced utterances in a normal condition and in a bite-block condition in which the mandible was in a fixed position. In children with DAS, the bite-block had large effects on coarticulatory patterns and vowel quality. (Contains references.) (Author/CR)

  20. Pedagogical Basis of DAS Formalism in Engineering Education

    ERIC Educational Resources Information Center

    Hiltunen, J.; Heikkinen, E.-P.; Jaako, J.; Ahola, J.

    2011-01-01

    The paper presents a new approach for a bachelor-level curriculum structure in engineering. The approach is called DAS formalism according to its three phases: description, analysis and synthesis. Although developed specifically for process and environmental engineering, DAS formalism has a generic nature and it could also be used in other…

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

    PubMed

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

    2013-06-01

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

  2. LONGITUDINAL LASER WIRE AT SNS

    SciTech Connect

    Aleksandrov, Alexander V; Liu, Yun; Zhukov, Alexander P

    2014-01-01

    This paper describes a longitudinal H- beam profile scanner that utilizes laser light to detach convoy electrons and an MCP to collect and measure these electrons. The scanner is located in MEBT with H- energy of 2.5MeV and an RF frequency 402.5MHz. The picosecond pulsed laser runs at 80.5MHz in sync with the accelerator RF. The laser beam is delivered to the beam line through a 30m optical fiber. The pulse width after the fiber transmission measures about 10ps. Scanning the laser phase effectively allows measurements to move along ion bunch longitudinal position. We are able to reliably measure production beam bunch length with this method. The biggest problem we have encountered is background signal from electrons being stripped by vacuum. Several techniques of signal detection are discussed.

  3. The Importance of Longitudinal Studies

    NASA Astrophysics Data System (ADS)

    Knezek, Patricia

    2014-01-01

    It has been eight years since the AAS Council unanimously endorsed the document, known as "Equity Now: The Pasadena Recommendations for Gender Equality in Astronomy," in January 2005. This document was the main product of the conference entitled “Women in Astronomy II: Ten Years After” (WIA II), held in June 2003 in Pasadena, CA. One of the key recommendations represented in that document was the need for a longitudinal study of astronomers. It was recognized that in order to understand our own field, how it is evolving, and the impact on individuals, we need to track people over time. I will discuss the fundamental questions that led to the recommendation, and set the stage for the current (ongoing) longitudinal study.

  4. Longitudinal normals for piezoelectric elastic media

    NASA Astrophysics Data System (ADS)

    Duda, A.; Paszkiewicz, T.; Wolski, S.

    2006-02-01

    We show that the problem of finding components of longitudinal normals for all piezoelectric classes is equivalent to the problem of solving two sets of two polynomial equations up to 6th degree. It is proved that the number of longitudinal normals for triclinic media cannot exceed 36. If the number of longitudinal normals contained in any plane is finite, then it cannot be larger than 6. Directions of longitudinal normals are found for quartz, LiGaO2, and Ba2NaNb5O15. For these compounds we numerically studied how piezoelectric terms of the propagation matrix influence the number and directions of the longitudinal normals.

  5. Hemorrhagic Longitudinally Extensive Transverse Myelitis

    PubMed Central

    Wu, Chris Y.; Riangwiwat, Tanawan

    2016-01-01

    Longitudinally extensive transverse myelitis (LETM) may be associated with viral triggers, including both infections and vaccinations. We present a case of a healthy immunocompetent 33-year-old woman who developed a hemorrhagic LETM 2 weeks after seasonal influenza vaccination. Hemorrhagic LETM has not to our knowledge been reported after influenza vaccination. It may represent a forme fruste variant of acute hemorrhagic leukoencephalitis. PMID:27847660

  6. Longitudinal bulk acoustic mass sensor

    NASA Astrophysics Data System (ADS)

    Hales, J. H.; Teva, J.; Boisen, A.; Davis, Z. J.

    2009-07-01

    A polycrystalline silicon longitudinal bulk acoustic cantilever is fabricated and operated in air at 51 MHz. A mass sensitivity of 100 Hz/fg (1 fg=10-15 g) is obtained from the preliminary experiments where a minute mass is deposited on the device by means of focused ion beam. The total noise in the currently applied measurement system allows for a minimum detectable mass of 0.5 fg in air.

  7. Longitudinal bulk acoustic mass sensor

    SciTech Connect

    Hales, J. H.; Teva, J.; Boisen, A.; Davis, Z. J.

    2009-07-20

    A polycrystalline silicon longitudinal bulk acoustic cantilever is fabricated and operated in air at 51 MHz. A mass sensitivity of 100 Hz/fg (1 fg=10{sup -15} g) is obtained from the preliminary experiments where a minute mass is deposited on the device by means of focused ion beam. The total noise in the currently applied measurement system allows for a minimum detectable mass of 0.5 fg in air.

  8. Parameterized Linear Longitudinal Airship Model

    NASA Technical Reports Server (NTRS)

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

    2010-01-01

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

  9. Estudo espectral em raios-X duros de fontes do tipo Z com o HEXTE/RXTE

    NASA Astrophysics Data System (ADS)

    D'Amico, F.; Heindl, W. A.; Rothschild, R. E.

    2003-08-01

    Apresentam-se os resultados de um estudo espectral em raios-X de fontes do tipo Z. As fontes do tipo Z são binárias de raios-X de baixa massa (BXBM) com campo magnético intermediário (B~109G). Esta classe de fontes é composta por apenas 6 fontes Galácticas (a saber: ScoX-1, 9, 7, CygX-2, 5 e 0). A nossa análise se concentra na faixa de raios-X duros (E ~ 20keV), até cerca de 200keV, faixa ótima de operação do telescópio "High Energy X-ray Timing Experiment" (HEXTE), um dos três telescópios de raios-X à bordo do Rossi X-ray Timing Explorer (RXTE). Nossa motivação para tal estudo, uma busca de caudas em raios-X duros em fontes do tipo Z, foi o pouco conhecimento sobre a emissão nesta faixa de energia das referidas fontes quando comparadas, por exemplo, as fontes do tipo atoll (também BXBM). Apresentam-se a análise/redução de dados e explicita-se a maneira como o HEXTE mede o ru1do de fundo. Especial atenção é direcionada a este item devido a localização das fontes do tipo Z e também ao problema de contaminação por fontes próximas. Com exceção de ScoX-1, nenhuma cauda em raios-X duros foi encontrada para as outras fontes, a despeito de resultados de detecção dessas caudas em algumas fontes pelo satélite BeppoSAX. As interpretações deste resultado serão apresentadas. Do ponto de vista deste estudo, nós deduzimos que a produção de caudas de raios-X duros em fontes do tipo Z é um processo disparado quando, pelo menos, uma condição é satisfeita: o brilho da componente térmica do espectro precisa estar acima de um certo valor limiar de ~4´1036ergs-1.

  10. Twenty‐eight‐joint counts invalidate the DAS28 remission definition owing to the omission of the lower extremity joints: a comparison with the original DAS remission

    PubMed Central

    Landewé, R; van der Heijde, D; van der Linden, S; Boers, M

    2006-01-01

    Objective To compare 28 joint disease activity score (DAS28) remission with comprehensive joint count DAS remission in rheumatoid arthritis. Methods 620 actually measured paired observations of DAS28 and DAS were analysed in 155 patients. Discordant observations (either DAS or DAS28 below remission cut off level: 1.6 for DAS and 2.6 for DAS28) and concordant observations (both DAS and DAS28 below their remission cut off level) were analysed separately. Results 91 of 620 paired DAS observations (15%) were discordant; 87 (in 53 patients) comprised observations in which the DAS28 remission criterion, but not the DAS remission criterion, was met. The reverse was found in only four observations, which were therefore omitted. With the original DAS as standard, DAS28 sensitivity was 95% and specificity 84%. Probability plots showed a swollen joint count >0 in 75% of discordant pairs v 48% of concordant pairs. The same was found for total joint count (TJC >0 in 90% v 40%; median TJC, 0 v 6) and patient global assessment, but not for ESR. Individual joint analysis showed that 51% of discordant v 18% of concordant observations (p<0.0005) had involvement of lower extremity joints that are not included in the DAS28. Conclusions DAS remission is more conservative than DAS28 remission. Activity (tenderness and swelling) in joints not included in the reduced joint counts (ankles, feet) mainly account for the discrepancy between the two assessments. DAS28 remission at a cut off level of 2.6 has insufficient construct validity and should be used with caution in clinical practice and clinical trials. PMID:16219709

  11. A causa das estações do ano: modelos mentais

    NASA Astrophysics Data System (ADS)

    de Campos, J. A. S.; de Araujo, J. F. S.

    2003-08-01

    A década de 70 do século passado foi marcada pelo estudo das concepções alternativas que os alunos trazem para a sala de aula. A identificação destas concepções foi o ponto de partida para promover a mudança conceitual, onde as pré-concepções seriam trocadas pelas concepções científicas. Na década seguinte, surgiram muitas propostas de estratégias educacionais para facilitar esta troca, na sua maioria baseadas na idéia do conflito cognitivo, proposta por Piaget. Entretanto, os resultados pouco animadores conduziram à percepção de que a mudança conceitual é um processo mais complexo. Pelas idéias da Ciência Cognitiva, a mudança conceitual é uma mudança progressiva dos modelos mentais que o aluno tem sobre o mundo físico, através de enriquecimento e revisão. A causa das Estações do Ano é um tópico sobre o qual a maioria dos estudantes apresenta concepções alternativas. Os autores fizeram um levantamento sobre as pré-concepções encontradas em trabalhos sobre o tema (16 referências), procurando encontrar elementos comuns que indicassem a presença de modelos mentais específicos. As pré-concepções encontradas na literatura foram obtidas usando-se diversas metodologias (desde entrevistas clínicas até questionários de múltipla escolha) e envolvendo alunos e professores de diferentes regiões geográficas. A partir de uma análise aprofundada de cada trabalho, e utilizando-se a técnica das Redes Sistêmicas, chegou-se a conclusão que as diversas pré-concepções identificadas (em torno de 50), poderiam ser representadas por 6 modelos mentais, onde a explicação da causa das estações do ano tem um mecanismo causal responsável. Os mecanismos causais identificados foram: a dependência da distância, a dependência da orientação, a dependência conjunta da distância e orientação, a dependência da obstrução, a dependência da velocidade e a dependência da inclinação dos raios solares. Foram ainda identificadas

  12. Longitudinal Control of Intense Charged Particle Beams

    DTIC Science & Technology

    2011-01-01

    contained using longitudinal focusing, I have shown that errors in the applied focusing fields induce space-charge waves at the bunch edges that...profile along the bunch length. When the bunch is contained using longitudinal focusing, I have shown that errors in the applied focusing fields ...90 5.1.1 Beam Expansion without Longitudinal Containment................................ 90 5.1.2 Application of Focusing Fields

  13. 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.

  14. 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

  15. DAS: A Data Management System for Instrument Tests and Operations

    NASA Astrophysics Data System (ADS)

    Frailis, M.; Sartor, S.; Zacchei, A.; Lodi, M.; Cirami, R.; Pasian, F.; Trifoglio, M.; Bulgarelli, A.; Gianotti, F.; Franceschi, E.; Nicastro, L.; Conforti, V.; Zoli, A.; Smart, R.; Morbidelli, R.; Dadina, M.

    2014-05-01

    The Data Access System (DAS) is a and data management software system, providing a reusable solution for the storage of data acquired both from telescopes and auxiliary data sources during the instrument development phases and operations. It is part of the Customizable Instrument WorkStation system (CIWS-FW), a framework for the storage, processing and quick-look at the data acquired from scientific instruments. The DAS provides a data access layer mainly targeted to software applications: quick-look displays, pre-processing pipelines and scientific workflows. It is logically organized in three main components: an intuitive and compact Data Definition Language (DAS DDL) in XML format, aimed for user-defined data types; an Application Programming Interface (DAS API), automatically adding classes and methods supporting the DDL data types, and providing an object-oriented query language; a data management component, which maps the metadata of the DDL data types in a relational Data Base Management System (DBMS), and stores the data in a shared (network) file system. With the DAS DDL, developers define the data model for a particular project, specifying for each data type the metadata attributes, the data format and layout (if applicable), and named references to related or aggregated data types. Together with the DDL user-defined data types, the DAS API acts as the only interface to store, query and retrieve the metadata and data in the DAS system, providing both an abstract interface and a data model specific one in C, C++ and Python. The mapping of metadata in the back-end database is automatic and supports several relational DBMSs, including MySQL, Oracle and PostgreSQL.

  16. Arthritis instantaneously causes collagen type I and type II degradation in patients with early rheumatoid arthritis: a longitudinal analysis

    PubMed Central

    Landewé, R B M; Geusens, P; van der Heijde, D M F M; Boers, M; van der Linden, S J; Garnero, P

    2006-01-01

    Background Markers of collagen type I (CTX‐1) and type II (CTX‐II) degradation, reflecting bone and cartilage breakdown, appear to predict long term radiographic progression in chronic persistent arthritis. Objective To analyse longitudinally whether changes in arthritis severity are linked to immediate changes in the level of CTX‐I and CTX‐II degradation. Methods CTX‐I and CTX‐II were measured in urine samples from 105 patients with early rheumatoid arthritis who had participated in the COBRA trial at baseline and at 3, 6, 9, and 12 months after the start of treatment. The course of the biomarkers over time was compared with the course of ESR, swollen and tender joint counts, and 28 joint disease activity score (DAS28), measured at the same time points, with adjustment for rheumatoid factor, treatment, and baseline radiographic damage, by generalised estimating equations (GEE) with first order autoregression. Results GEE showed that CTX‐I was longitudinally associated with DAS28, but not with ESR, swollen joint count, or tender joint count. CTX‐II, however, was longitudinally associated with ESR, swollen joint count and DAS28, but not with tender joint count. The longitudinal association implies that an increase in the extent of arthritis is immediately followed by an increase in collagen type II degradation, and to a lesser extent collagen type I degradation. Conclusions Cartilage degradation as measured by CTX‐II and to a lesser extent bone degradation as measured by CTX‐I closely follows indices of arthritis. Clinically perceptible arthritis is responsible for immediate damage, which will become visible on plain x rays only much later. PMID:16126801

  17. Transverse-longitudinal integrated resonator

    DOEpatents

    Hutchinson, Donald P [Knoxville, TN; Simpson, Marcus L [Knoxville, TN; Simpson, John T [Knoxville, TN

    2003-03-11

    A transverse-longitudinal integrated optical resonator (TLIR) is disclosed which includes a waveguide, a first and a second subwavelength resonant grating in the waveguide, and at least one photonic band gap resonant structure (PBG) in the waveguide. The PBG is positioned between the first and second subwavelength resonant gratings. An electro-optic waveguide material may be used to permit tuning the TLIR and to permit the TLIR to perform signal modulation and switching. The TLIR may be positioned on a bulk substrate die with one or more electronic and optical devices and may be communicably connected to the same. A method for fabricating a TLIR including fabricating a broadband reflective grating is disclosed. A method for tuning the TLIR's transmission resonance wavelength is also disclosed.

  18. Modeling a Longitudinal Relational Research Data Systems

    ERIC Educational Resources Information Center

    Olsen, Michelle D. Hunt

    2010-01-01

    A study was conducted to propose a research-based model for a longitudinal data research system that addressed recommendations from a synthesis of literature related to: (1) needs reported by the U.S. Department of Education, (2) the twelve mandatory elements that define federally approved state longitudinal data systems (SLDS), (3) the…

  19. Colorado Longitudinal Twin Study of Reading Disability

    ERIC Educational Resources Information Center

    Wadsworth, Sally J.; DeFries, John C.; Olson, Richard K.; Willcutt, Erik G.

    2007-01-01

    The primary objectives of the present study are to introduce the Colorado Longitudinal Twin Study of Reading Disability, the first longitudinal twin study in which subjects have been specifically selected for having a history of reading difficulties, and to present some initial assessments of the stability of reading performance and cognitive…

  20. Fears in Czech Adolescents: A Longitudinal Study

    ERIC Educational Resources Information Center

    Michalcáková, Radka; Lacinová, Lenka; Kyjonková, Hana; Bouša, Ondrej; Jelínek, Martin

    2013-01-01

    The present study investigates developmental patterns of fear in adolescence. It is based on longitudinal data collected as a part of the European Longitudinal Study of Pregnancy and Childhood (ELSPAC) project. A total of 186 Czech adolescents (43% girls) were assessed repeatedly at the age of 11, 13, and 15 years. The free-response method was…

  1. Fears in Czech Adolescents: A Longitudinal Study

    ERIC Educational Resources Information Center

    Michalcáková, Radka; Lacinová, Lenka; Kyjonková, Hana; Bouša, Ondrej; Jelínek, Martin

    2013-01-01

    The present study investigates developmental patterns of fear in adolescence. It is based on longitudinal data collected as a part of the European Longitudinal Study of Pregnancy and Childhood (ELSPAC) project. A total of 186 Czech adolescents (43% girls) were assessed repeatedly at the age of 11, 13, and 15 years. The free-response method was…

  2. Colorado Longitudinal Twin Study of Reading Disability

    ERIC Educational Resources Information Center

    Wadsworth, Sally J.; DeFries, John C.; Olson, Richard K.; Willcutt, Erik G.

    2007-01-01

    The primary objectives of the present study are to introduce the Colorado Longitudinal Twin Study of Reading Disability, the first longitudinal twin study in which subjects have been specifically selected for having a history of reading difficulties, and to present some initial assessments of the stability of reading performance and cognitive…

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

    ERIC Educational Resources Information Center

    Aleman, Ana M. Martinez

    2010-01-01

    This article presents a longitudinal qualitative study of the cognitive value of female friendships formed in college and seeks to appraise the meaning of the phenomenon for the participants. To grasp the temporal effects of the longitudinal data in this study, the author examines and assesses the relevant developmental literature, particularly…

  4. Modeling a Longitudinal Relational Research Data Systems

    ERIC Educational Resources Information Center

    Olsen, Michelle D. Hunt

    2010-01-01

    A study was conducted to propose a research-based model for a longitudinal data research system that addressed recommendations from a synthesis of literature related to: (1) needs reported by the U.S. Department of Education, (2) the twelve mandatory elements that define federally approved state longitudinal data systems (SLDS), (3) the…

  5. Longitudinal research in child and adolescent psychiatry.

    PubMed

    Verhulst, F C; Koot, H M

    1991-05-01

    An indispensable approach to the study of variations in individual development and of causal mechanisms and processes underlying the course of psychopathology is the longitudinal method. In this introductory review, the strengths and weaknesses of longitudinal research are discussed, and factors hampering progress in this field are outlined. The many advantages of this approach warrant continuing efforts to develop strategies that minimize its drawbacks.

  6. Pedagogical basis of DAS formalism in engineering education

    NASA Astrophysics Data System (ADS)

    Hiltunen, J.; Heikkinen, E.-P.; Jaako, J.; Ahola, J.

    2011-03-01

    The paper presents a new approach for a bachelor-level curriculum structure in engineering. The approach is called DAS formalism according to its three phases: description, analysis and synthesis. Although developed specifically for process and environmental engineering, DAS formalism has a generic nature and it could also be used in other engineering fields. The motivation for this new curriculum structure originates from the urge to solve the problems that engineering education has faced during the past decades, e.g. student recruitment problems and dissatisfactory learning outcomes. The focus of this paper is on the structure of the curriculum but the content is also discussed when it has an effect on the structure and its implementation. The presented structure, i.e. DAS formalism, builds upon the ideas of some classical pedagogical theories, which have regularly been applied at course level but seldom used to solve curriculum-level issues.

  7. Vallabhaneni Sita Rama Das, 1933-2010: teacher and mentor.

    PubMed

    Elchuri, Sailaja V; Govindjee

    2016-05-01

    We present here the life and research of V. S. Rama Das, a distinguished Indian botanist who specialized in photosynthesis. He was the first to purify chloroplasts that were free of mitochondrial contamination. He then studied C4, C3-C4 intermediate and CAM pathways, as well as their taxonomic distribution in tropical climates. His most valuable legacy is that he, as a philosopher, inspired and guided many students to pursue their research career in India. Also see Narayana and Pullaiah (Eminent Indian Botanists: Past and present: Biographies and contributions, pp 394-401, 2010) and Raghavendra and Reddy (Curr Sci 101:798-799, 2011) for further information on Rama Das.

  8. LSTGEE: longitudinal analysis of neuroimaging data

    NASA Astrophysics Data System (ADS)

    Li, Yimei; Zhu, Hongtu; Chen, Yasheng; An, Hongyu; Gilmore, John; Lin, Weili; Shen, Dinggang

    2009-02-01

    Longitudinal imaging studies are essential to understanding the neural development of neuropsychiatric disorders, substance use disorders, and normal brain. Using appropriate image processing and statistical tools to analyze the imaging, behavioral, and clinical data is critical for optimally exploring and interpreting the findings from those imaging studies. However, the existing imaging processing and statistical methods for analyzing imaging longitudinal measures are primarily developed for cross-sectional neuroimaging studies. The simple use of these cross-sectional tools to longitudinal imaging studies will significantly decrease the statistical power of longitudinal studies in detecting subtle changes of imaging measures and the causal role of time-dependent covariate in disease process. The main objective of this paper is to develop longitudinal statistics toolbox, called LSTGEE, for the analysis of neuroimaging data from longitudinal studies. We develop generalized estimating equations for jointly modeling imaging measures with behavioral and clinical variables from longitudinal studies. We develop a test procedure based on a score test statistic and a resampling method to test linear hypotheses of unknown parameters, such as associations between brain structure and function and covariates of interest, such as IQ, age, gene, diagnostic groups, and severity of disease. We demonstrate the application of our statistical methods to the detection of the changes of the fractional anisotropy across time in a longitudinal neonate study. Particularly, our results demonstrate that the use of longitudinal statistics can dramatically increase the statistical power in detecting the changes of neuroimaging measures. The proposed approach can be applied to longitudinal data with multiple outcomes and accommodate incomplete and unbalanced data, i.e., subjects with different number of measurements.

  9. The development of the disease activity score (DAS) and the disease activity score using 28 joint counts (DAS28).

    PubMed

    van Riel, P L C M

    2014-01-01

    In rheumatoid arthritis, disease activity cannot be measured using a single variable. The Disease Activity Score (DAS) has been developed as a quantitative index to be able to measure, study and manage disease activity in RA in daily clinical practice, clinical trials, and long term observational studies. The DAS is a continuous measure of RA disease activity that combines information from swollen joints, tender joints, acute phase response and patient self-report of general health. Cut points were developed to classify patients in remission, as well as low, moderate, and severe disease activity in the 1990s. DAS-based EULAR response criteria were primarily developed to be used in clinical trials to classify individual patients as non-, moderate, or good responders, depending on the magnitude of change and absolute level of disease activity at the conclusion of the test.

  10. ProServer: a simple, extensible Perl DAS server.

    PubMed

    Finn, Robert D; Stalker, James W; Jackson, David K; Kulesha, Eugene; Clements, Jody; Pettett, Roger

    2007-06-15

    The increasing size and complexity of biological databases has led to a growing trend to federate rather than duplicate them. In order to share data between federated databases, protocols for the exchange mechanism must be developed. One such data exchange protocol that is widely used is the Distributed Annotation System (DAS). For example, DAS has enabled small experimental groups to integrate their data into the Ensembl genome browser. We have developed ProServer, a simple, lightweight, Perl-based DAS server that does not depend on a separate HTTP server. The ProServer package is easily extensible, allowing data to be served from almost any underlying data model. Recent additions to the DAS protocol have enabled both structure and alignment (sequence and structural) data to be exchanged. ProServer allows both of these data types to be served. ProServer can be downloaded from http://www.sanger.ac.uk/proserver/ or CPAN http://search.cpan.org/~rpettett/. Details on the system requirements and installation of ProServer can be found at http://www.sanger.ac.uk/proserver/.

  11. Breaking of longitudinal Akhiezer-Polovin waves.

    PubMed

    Verma, Prabal Singh; Sengupta, Sudip; Kaw, Predhiman

    2012-03-23

    The breaking of longitudinal Akhiezer-Polovin (AP) waves is demonstrated using a one-dimensional simulation based on the Dawson sheet model. It is found that the AP longitudinal waves break through the process of phase mixing at an amplitude well below the breaking amplitude for AP waves, when subjected to arbitrarily small longitudinal perturbations. Results from the simulation show a good agreement with the Dawson phase mixing formula modified to include relativistic mass variation effects. This result may be of direct relevance to the laser- or particle-beam plasma wakefield experiments.

  12. Estudo exaustivo e sistemático de erros nas provas da olimpíada brasileira de astronomia - resultados preliminares

    NASA Astrophysics Data System (ADS)

    Oliveira, F. S.; Canalle, J. B. G.; Villas da Rocha, J. F.

    2003-08-01

    A Olimpíada Brasileira de Astronomia (OBA) contou, em sua quinta edição, com a participação de mais de 60 mil alunos dos ensinos fundamental e médio de praticamente todo o território nacional. Uma das formas de controle que a sua coordenação nacional possui sobre a correção, levada a cabo pelos professores que as aplicaram, é a do envio, por parte destes professores, das 10 melhores provas de cada um dos três níveis nos quais a Olimpíada é realizada. Assim, e dado ao caráter discursivo das provas da Olimpíada, a sua coordenação nacional dispõe de um vasto acervo sobre as concepções, certas ou erradas, dos alunos que dela participaram. Este conjunto de dados jamais fora explorado até o presente trabalho que pretende ser, neste sentido, inaugural. Nas provas dos níveis I e II da V OBA, que abrangem todo o conjunto do ensino fundamental, uma das questões versava sobre a noção que os alunos tinham sobre como os habitantes da Terra situam-se sobre sua superfície. Fizemos um estudo sistemático das respostas a esta questão. Primeiramente, todas as modalidades de erros foram levantadas; em seguida, realizamos uma distribuição por idade tanto do índice de acerto como da ocorrência e da distribuição de cada erro. Como resultado, obtivemos que, em ambos os níveis: 1) as concepções errôneas não se apresentam distribuídas aleatoriamente; 2) há uma concentração no tipo de erro apresentado; 3) há uma tendência de progressivo acerto com relação à idade quando os dados são considerados em termos nacionais; 4) esta tendência nacional é fraca ou mesmo não é verificada em alguns dos estados com maior patamar de acerto.

  13. A longitudinal study of confabulation.

    PubMed

    Dalla Barba, Gianfranco; Brazzarola, Marta; Marangoni, Sara; Barbera, Claudia; Zannoni, Ilaria

    2017-02-01

    Confabulation, the production of statements and actions that are unintentionally incongruous to the subject's history, background, present and future situation, is a rather infrequent disorder, observed in several conditions affecting the nervous system. Little is known about the quantitative and qualitative evolution of confabulation in time. In this study we evaluated longitudinally the evolution of this disorder in a group of severe confabulators, using the Confabulation Battery (CB), a sensitive tool to detect confabulations in various memory domains. It was found that confabulations were stable over time and not temporally limited. It was also found that "Habits Confabulations" (HCs), i.e., habits and repeated personal events mistaken as specific, unique past and future personal episodes, or well-known public events when semantic knowledge is concerned, was the more frequently observed type of confabulation. Confabulations were also more prominent in the domain of Temporal Consciousness (TC), i.e., a specific form of consciousness that allows individuals to remember their personal past, to be oriented in their present world and to predict their personal future, than in Knowing Consciousness (KC), i.e., a specific form of consciousness allowing individuals to be aware of past, present and future impersonal knowledge and information. Confabulations showed also persistence, i.e., confabulations at the same questions over time, and consistency, i.e., same type of confabulation at the same question over time. These findings are discussed within the framework of the Memory, Consciousness and Temporality Theory.

  14. Longitudinal Variations in Jupiter's Winds

    NASA Technical Reports Server (NTRS)

    Simon-Miller, Amy A.; Gierasch, P. J.; Tierney, G.

    2010-01-01

    Long-term studies of Jupiter's zonal wind field revealed temporal variations on the order of 20 to 40 m/s at many latitudes, greater than the typical data uncertainties of 1 to 10 m/s. No definitive periodicities were evident, however, though some latitudinally-confined signals did appear at periods relevant to the Quasi- Quadrennial Oscillation (Simon-Miller & Gierasch, Icarus, in press). As the QQO appears, from vertical temperature profiles, to propagate downward, it is unclear why a signal is not more obvious, unless other processes dominate over possibly weaker forcing from the QQO. An additional complication is that zonal wind profiles represent an average over some particular set of longitudes for an image pair and most data sets do not offer global wind coverage. Lien avoiding known features, such as the large anticyclonic vortices especially prevalent in the south, there can be distinct variations in longitude. We present results on the full wind field from Voyager and Cassini data, showing apparent longitudinal variations of up to 60 m/s or more. These are particularly obvious near disruptions such as the South Equatorial Disturbance, even when the feature itself is not clearly visible. These two dates represent very different states of the planet for comparison: Voyagers 1 & 2 flew by Jupiter shortly after a global upheaval, while many regions were in a disturbed state, while the Cassini view is typical of a more quiescent period present during much of the 1990s and early 2000s.

  15. Underemployment and depression: longitudinal relationships.

    PubMed

    Dooley, D; Prause, J; Ham-Rowbottom, K A

    2000-12-01

    We conceptualize employment status not as a dichotomy of working versus not working but as a continuum ranging from adequate employment to inadequate employment (involuntary part-time or low wage) to unemployment. Will shifts from adequate to inadequate employment increase depression as do shifts from employment to unemployment, and to what extent does prior depression select workers into such adverse employment change? We analyze panel data from the National Longitudinal Survey of Youth for the years 1992-1994 for the 5,113 respondents who were adequately employed in 1992. Controlling for prior depression, both types of adverse employment change resulted in similar, significant increases in depression. These direct effects persisted despite inclusion of such potential mediators as changes in income, job satisfaction, and marital status. Marital status buffered the depressive effect of both types of adverse change, but education and job dissatisfaction amplified the effect of unemployment on depression. Prior depression did not predict higher risk of becoming inadequately employed but did predict increased risk of unemployment, particularly for those with less education. These results confirm that both unemployment and inadequate employment affect mental health, and they invite greater efforts to monitor the extent and impact of underemployment.

  16. Longitudinal oscillation of launch vehicles

    NASA Technical Reports Server (NTRS)

    Glaser, R. F.

    1973-01-01

    During powered flight a vehicle may develop longitudinal self-excited oscillations, so-called oscillations, of its structure. The energy supplying the vibration is tapped from the thrust by the activity of the system itself; that is, oscillation of the structure causes oscillation of the propellant system, especially of the pumps. In this way an oscillating thrust can be created that, by a feedback loop, may sustain the structural oscillation under certain circumstances. Two special features of the system proved to be essential for creation of instability. One is the effect of the inherent time interval that the thrust oscillation is lagging behind the structural oscillation. The other is the decreased of system mass caused by the exhausting of gas. The latter feature may cause an initially stable system to become unstable. To examine the stability of the system, a single mass-spring model, which is the result of a one-term Galerkin approach to the equation of motion, has been considered. The Nyquist stability criterion leads to a stability graph that shows the stability conditions in terms of the system parameter and also demonstrates the significance of time lag, feedback magnitude, and loss of mass. An important conclusion can be drawn from the analysis: large relative displacements of the pump-engine masses favor instability. This is also confirmed by flight measurements.

  17. Longitudinal impedance of single frog muscle fibers

    PubMed Central

    1975-01-01

    The longitudinal impedance of single skeletal muscle fibers has been measured from1 to 10,000 Hz in an oil gap apparatus which forces current to flow longitudinally down the fiber. The impedance observed is purely resistive in some fibers from the semitendinosus muscle and in two fibers from the sartorius muscle. In other fibers from the semitendinosus muscle a small phase shift is observed. The mean value of the maximum phase shift observed from all fibers is 1.07 degrees. The artifacts associated with the apparatus and method are examined theoretically and it is shown that one of the likely artifacts could account for the small phase observed. It is concluded that the longitudinal impedance of skeletal muscle fibers is essentially resistive and that little, if any, longitudinal current crosses the membranes of the sarcoplasmic reticulum. PMID:1078575

  18. Longitudinally extensive optic neuritis in pediatric patients.

    PubMed

    Graves, Jennifer; Kraus, Verena; Soares, Bruno P; Hess, Christopher P; Waubant, Emmanuelle

    2015-01-01

    Extensive optic nerve demyelinating lesions on magnetic resonance imaging (MRI) in adults could indicate a diagnosis other than multiple sclerosis with worse prognosis such as neuromyelitis optica. We report the frequency of longitudinally extensive lesions in children with first events of optic neuritis. Subjects had brain or orbit MRI within 3 months of onset and were evaluated at the University of California, San Francisco, Pediatric Multiple Sclerosis Center. Lesion length, determined by T2 hyperintensity or contrast enhancement, was blindly graded as absent, focal or longitudinally extensive (at least 2 contiguous segments of optic nerve). Of 25 subjects, 9 (36%) had longitudinally extensive optic neuritis. Extensive lesions were not associated with non-multiple sclerosis versus multiple sclerosis diagnosis (P = 1.00). No association between age and lesion extent was observed (P = .26). Prospective studies are needed to determine if longitudinally extensive optic neuritis can predict visual outcome.

  19. Ultimate Longitudinal Strength of Composite Ship Hulls

    NASA Astrophysics Data System (ADS)

    Zhang, Xiangming; Huang, Lingkai; Zhu, Libao; Tang, Yuhang; Wang, Anwen

    2017-01-01

    A simple analytical model to estimate the longitudinal strength of ship hulls in composite materials under buckling, material failure and ultimate collapse is presented in this paper. Ship hulls are regarded as assemblies of stiffened panels which idealized as group of plate-stiffener combinations. Ultimate strain of the plate-stiffener combination is predicted under buckling or material failure with composite beam-column theory. The effects of initial imperfection of ship hull and eccentricity of load are included. Corresponding longitudinal strengths of ship hull are derived in a straightforward method. A longitudinally framed ship hull made of symmetrically stacked unidirectional plies under sagging is analyzed. The results indicate that present analytical results have a good agreement with FEM method. The initial deflection of ship hull and eccentricity of load can dramatically reduce the bending capacity of ship hull. The proposed formulations provide a simple but useful tool for the longitudinal strength estimation in practical design.

  20. Transverse-longitudinal coupling in intense beams

    SciTech Connect

    Wang, T.S.F.; Smith, L.

    1981-03-01

    The coupling between transverse and longitudinal perturbations is studied self-consistently by considering a beam of K-V distribution. The analysis is carried out within the context of linearized Vlasov-Maxwell equations and electrostatic approximation. The perturbation is assumed to be azimuthally symmetric but axially non-uniform (k/sub z/ is not equal to 0). It is shown that the coupling affects both the longitudinal and transverse modes significantly in the high density and low frequency region. Two new classes of longitudinal modes are found which would not exist if the transverse motions of particles are neglected. The effect of resistive wall impedance on beam stability is also studied. It is found that the longitudinal impedance can cause the transverse modes also to be weakly unstable.

  1. The Lighthouse Program: A Longitudinal Research Project.

    ERIC Educational Resources Information Center

    LaRose, Barbara

    1986-01-01

    Longitudinal data are presented from the Lighthouse Program for gifted students which features cluster grouping and a quota identification systems to ensure proportionate inclusion of minority students. (Author/CL)

  2. Longitudinal research strategies: advantages, problems, and prospects.

    PubMed

    Farrington, D P

    1991-05-01

    The single-cohort, long-term longitudinal survey has many advantages in comparison with a cross-sectional survey in advancing knowledge about offending and other types of psychopathology, notably in providing information about onset and desistance, about continuity and prediction, and about within-individual change. However, the longitudinal survey also has significant problems, notably in confounding aging and period effects, delayed results, achieving continuity in funding and research direction, and cumulative attrition. This paper suggests the use of a multiple-cohort sequential strategy (the "accelerated longitudinal design") as a way of achieving the benefits of the longitudinal method while minimizing the problems in advancing knowledge about the natural history, causes, prevention, and treatment of psychopathological disorders.

  3. 14 CFR 23.145 - Longitudinal control.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Longitudinal control. 23.145 Section 23.145... Maneuverability § 23.145 Longitudinal control. (a) With the airplane as nearly as possible in trim at 1.3 VS1, it... application of single-handed control forces exceeding those specified in § 23.143(c). The trimming...

  4. Longitudinal space charge effects near transition

    SciTech Connect

    Pozdeyev,E.; Rodriguez, J.A.; Marti, F.; York, R.C.

    2009-05-04

    Experimental and numerical studies of the longitudinal beam dynamics in the Small Isochronous Ring (SIR) at Michigan State University revealed a fast, space-charge driven instability that did not fit the model of the negative mass instability. This paper proposes a simple analytical model explaining these results. Also, the paper compares the model to result s of experimental and numerical studies of the longitudinal beam dynamics in SIR.

  5. Longitudinal study of keratoconus progression.

    PubMed

    Li, Xiaohui; Yang, Huiying; Rabinowitz, Yaron S

    2007-10-01

    To determine if differences in topographic progression between unaffected keratoconus relatives and normal controls can predict factors associated with the development of keratoconus in a longitudinal study. We recruited 369 unaffected keratoconus relatives and 119 normal controls in Los Angeles. Both eyes of subjects were examined at baseline clinically and by quantitative videokeratography and at a period ranging from 1 year to 8 years. Progression to keratoconus was evaluated by quantitative videokeratography variables. Unaffected relatives had higher Central K (CK), I-S and KISA values and were younger than normal controls (CK: 44.70 vs 44.01, P<0.01; I-S: 0.76 vs 0.58, P<0.01, KISA: 29.97 vs 23.89, P=0.02; age: 34.8 vs 41.0, P<0.01) at baseline. All three indices significantly increased with age, and CK and KISA values were associated with a positive family history for keratoconus (P<0.001 for CK and P=0.05 for KISA), however, the two groups were not statistically different in progression of keratoconus. After grouping unaffected relatives as high risk (age< or = 30 or Central K > or = 47.2 and I-S> or =1.2 or KISA> or = 60) and low risk (age>30 and Central K<47.2 and I-S<1.2 and KISA< 60), relatives in the high risk group had a greater increase in CK and I-S values than those in the low risk group (CK: P=0.009; I-S: P<0.001), which indicated that there were significantly different rates of progression between two groups. Unaffected relatives had higher videokeratography indices than normal controls, but overall they did not progress to keratoconus quicker than normal controls. However, relatives in the high risk group may have a greater risk of progression to keratoconus.

  6. Longitudinal study of keratoconus progression

    PubMed Central

    Li, Xiaohui; Yang, Huiying; Rabinowitz, Yaron S.

    2013-01-01

    To determine if differences in topographic progression between unaffected keratoconus relatives and normal controls can predict factors associated with the development of keratoconus in a longitudinal study. We recruited 369 unaffected keratoconus relatives and 119 normal controls in Los Angeles. Both eyes of subjects were examined at baseline clinically and by quantitative videokeratography and at a period ranging from 1 year to 8 years. Progression to keratoconus was evaluated by quantitative videokeratography variables. Unaffected relatives had higher Central K (CK), I-S and KISA values and were younger than normal controls (CK: 44.70 vs 44.01, P<0.01; I-S: 0.76 vs 0.58, P<0.01, KISA: 29.97 vs 23.89, P=0.02; age: 34.8 vs 41.0, P<0.01) at baseline. All three indices significantly increased with age, and CK and KISA values were associated with a positive family history for keratoconus (P<0.001 for CK and P=0.05 for KISA), however, the two groups were not statistically different in progression of keratoconus. After grouped unaffected relatives as the high risk (age<=30 or Central K>=47.2 or I-S >=1.2 or KISA>=60) and the low risk (age>30 and Central K<47.2 and I-S <1.2 and KISA<60), relatives in the high risk group had a greater increase in CK and I-S values than those in the low risk group (CK: p=0.009; I-S: p<0.001), which indicated that there were significantly different rates of progression between two groups. Unaffected relatives had higher videokeratography indices than normal controls, but overall they did not progress to keratoconus quicker than normal controls. However, relatives in a high risk group may have a greater risk of progression to keratoconus. PMID:17681291

  7. Desenvolvimento das câmeras de raios-X duros do satélite MIRAX

    NASA Astrophysics Data System (ADS)

    Braga, J.; Rothschild, R.; Staubert, R.; Heise, J.; Remillard, R.; D'Amico, F.; Jablonski, F.; Mejía, J.; Carvalho, H.; Heindl, B.; Matteson, J.; Kendziorra, E.; Wilms, J.; in't Zand, J.; Kuulkers, E.

    2003-08-01

    O MIRAX (Monitor e Imageador de RAios-X) é um projeto de desenvolvimento de um pequeno satélite astronômico de raios-X (~200 kg, ~240 W). A estratégia básica da missão será observar continuamente (~9 meses por ano) a região central (~1000 graus2) do plano Galáctico e realizar estudos espectroscópicos de banda larga (2-200 keV) e alta sensibilidade de um grande conjunto de fontes através de imagens com resolução de ~6'. Isso proporcionará uma cobertura inédita do "espaço de descobertas" através da detecção, localização, identificação e estudo detalhado de fenômenos imprevisíveis, tais como transientes fracos de raios-X, novas rápidas de raios-X e bursts de raios gama, assim como o estudo de fontes com emissão persistente. Neste trabalho apresentamos o projeto das duas câmeras de raios-X duros (CXDs) do MIRAX, que irão operar na faixa de 10 a 200 keV. Cada CXD consistirá de um plano de detectores CZT (Cd0,9Zn0,1Te) de 0,5 mm de resolução espacial e 370 cm2 de área total, e de uma máscara codificada com elementos quadrados de 1,3 mm de lado e 0,5 cm de espessura. A máscara terá dimensões de 315 cm ´ 275 cm e será montada a 700 cm de distância dos detectores. Com essa configuração as CXDs terão 6' de resolução angular e, quando colocadas a um ângulo de 29° entre si, as duas câmeras propiciam um campo totalmente codificado de 39° ´ 6°12' e um campo total de 76° ´ 44°. Serão apresentadas simulações de observações da região do plano Galáctico com o conjunto formado pelas duas CXDs.

  8. 14 CFR 25.175 - Demonstration of static longitudinal stability.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Demonstration of static longitudinal... Demonstration of static longitudinal stability. Static longitudinal stability must be shown as follows: (a... need not be less than 1.3 V SR 1. (b) Cruise. Static longitudinal stability must be shown in the...

  9. 14 CFR 25.175 - Demonstration of static longitudinal stability.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Demonstration of static longitudinal... Demonstration of static longitudinal stability. Static longitudinal stability must be shown as follows: (a... need not be less than 1.3 V SR 1. (b) Cruise. Static longitudinal stability must be shown in the...

  10. 14 CFR 25.175 - Demonstration of static longitudinal stability.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Demonstration of static longitudinal... Demonstration of static longitudinal stability. Static longitudinal stability must be shown as follows: (a... need not be less than 1.3 V SR 1. (b) Cruise. Static longitudinal stability must be shown in the...

  11. 14 CFR 25.175 - Demonstration of static longitudinal stability.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Demonstration of static longitudinal... Demonstration of static longitudinal stability. Static longitudinal stability must be shown as follows: (a... need not be less than 1.3 V SR 1. (b) Cruise. Static longitudinal stability must be shown in the...

  12. 14 CFR 25.175 - Demonstration of static longitudinal stability.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Demonstration of static longitudinal... Demonstration of static longitudinal stability. Static longitudinal stability must be shown as follows: (a... need not be less than 1.3 V SR 1. (b) Cruise. Static longitudinal stability must be shown in the...

  13. On the Law of Inertia. Translation of: Ueber das Beharrungsgesetz

    NASA Astrophysics Data System (ADS)

    Lange, Ludwig

    2014-04-01

    This article is a translation of Ludwig Lange: "Ueber das Beharrungsgesetz" in: Berichte ueber Verhandlungen der Koenigl. Saechsischen Gesellschaft der Wissenschaften, math.-physik. Klasse (Leipzig, 1885), SS. 333-351. Translated by Herbert Pfister, Institut für Theoretische Physik, Universität Tübingen, Auf der Morgenstelle 14, 72076 Tübingen, Germany; herbert.pfister@uni-tuebingen.de. Kind assistance by Julian Barbour is acknowledged.

  14. Método numérico das diferenças finitas no domínio do tempo aplicado a ondas Alfvén em plasma astrofísico

    NASA Astrophysics Data System (ADS)

    Dos Santos, L. C.; Kintopp, J. A.; Jatenco-Pereira, V.; Opher, R.

    2003-08-01

    Ondas Alfvén em plasma astrofísico têm sido objeto de intenso estudo nas últimas décadas pelo fato de apresentarem papel importante em muitas áreas de pesquisa na astrofísica. Particularmente são importantes no mecanismo de aquecimento da coroa solar; em ventos estelares; em jatos galácticos e extragalácticos; em discos protoestelares, etc. A formulação para diferenças finitas no domínio do tempo (FDTD), aplicada a plasma magnetizado é desenvolvida para estudo das propriedades de ondas Alfvén em três dimensões (3D-FDTD). O método é aplicado inicialmente a um plasma homogêneo e isotérmico imerso em uma região com campo magnético externo B0, que sofre uma pequena perturbação. Uma vez gerada a onda, esta perturbação é retirada e, então analisamos a evolução temporal das ondas, bem como a forma de seu amortecimento.

  15. LONGITUDINAL SPACE CHARGE EFFECT FOR SNS

    SciTech Connect

    ZHANG,S.Y.; WENG,W.T.

    1998-06-22

    One of performance requirements of the Spallation Neutron Source (SNS) is to keep the uncontrolled beam loss in the storage ring to less than 2 x 10{sup {minus}4} per pulse. For 2 MW SNS, the maximum beam intensity is N = 2 x 10{sup 14} protons per ring. Since the bunch lengthening has impact on both the extraction beam loss and the lowering of e-p instability threshold, the longitudinal space charge effect requires attentions. Such a space charge effect has been studied both analytically and using computer simulations. The longitudinal space charge effect, which is a defocusing force below transition, is a plausible source of the bunch leakage. In this article, the total RF potential, which takes into account the space charge effect together with the RF power, is used to provide analytical predictions for the bunch lengthening. The prediction is confirmed by the computer simulation. It is found that for 2 MW SNS storage ring, the longitudinal space charge induced bunch leakage into the interbunch gap is not significant. Therefore, corrections to the longitudinal space charge impedance, such as the proposed ferrite insertion in the PSR ring, are probably not necessary. Applying an RF voltage ramping from 20 KV to 40 KV during the multiturn injection can further cut the bunch leakage to a negligible degree. The same approach applied to the PSR shows that the longitudinal space charge effect does cause sizable bunch leakage at the intensity limit encountered there.

  16. Longitudinal stability in multiharmonic standing wave linacs

    DOE PAGES

    Carver, L. R.; Jones, R. M.; Jiang, Y.; ...

    2016-09-22

    Accelerating cavities that excite multiple modes at integer harmonics of the fundamental frequency have the potential to be used to suppress the onset of rf breakdown and reduce the pulsed surface heating at high accelerating gradients. Understanding the effect of an additional harmonic cavity mode on the longitudinal beam dynamics is important to their development and use. A Hamiltonian that describes the longitudinal motion of a particle as it traverses a chain of multiharmonic cavities has been derived and is applied to the case of a second harmonic cavity. The Hamiltonian is based upon formalisms found in literature for themore » fundamental harmonic and is extended to include different longitudinal field distributions and harmonic frequencies. The study initially explores the longitudinal motion for moderate accelerating gradients with high-β protons, as this will allow fundamental properties of the stable region (acceptance and shape of the rf bucket) to be determined. High accelerating gradients are also investigated but the focus will be on phase stability throughout. Finally, this work concludes by considering the longitudinal dynamics of a modified European Spallation Source accelerator, comprised of multiharmonic cavities that has specifications broadly consistent with the accelerator.« less

  17. Longitudinal stability in multiharmonic standing wave linacs

    NASA Astrophysics Data System (ADS)

    Carver, L. R.; Jones, R. M.; Jiang, Y.; Hirshfield, J. L.

    2016-09-01

    Accelerating cavities that excite multiple modes at integer harmonics of the fundamental frequency have the potential to be used to suppress the onset of rf breakdown and reduce the pulsed surface heating at high accelerating gradients. Understanding the effect of an additional harmonic cavity mode on the longitudinal beam dynamics is important to their development and use. A Hamiltonian that describes the longitudinal motion of a particle as it traverses a chain of multiharmonic cavities has been derived and is applied to the case of a second harmonic cavity. The Hamiltonian is based upon formalisms found in literature for the fundamental harmonic and is extended to include different longitudinal field distributions and harmonic frequencies. The study initially explores the longitudinal motion for moderate accelerating gradients with high-β protons, as this will allow fundamental properties of the stable region (acceptance and shape of the rf bucket) to be determined. High accelerating gradients are also investigated but the focus will be on phase stability throughout. This work concludes by considering the longitudinal dynamics of a modified European Spallation Source accelerator, comprised of multiharmonic cavities that has specifications broadly consistent with the accelerator.

  18. Longitudinal fluctuations and decorrelation of anisotropic flow

    NASA Astrophysics Data System (ADS)

    Pang, Long-Gang; Petersen, Hannah; Qin, Guang-You; Roy, Victor; Wang, Xin-Nian

    2016-12-01

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

  19. Multivariate analysis of longitudinal rates of change.

    PubMed

    Bryan, Matthew; Heagerty, Patrick J

    2016-12-10

    Longitudinal data allow direct comparison of the change in patient outcomes associated with treatment or exposure. Frequently, several longitudinal measures are collected that either reflect a common underlying health status, or characterize processes that are influenced in a similar way by covariates such as exposure or demographic characteristics. Statistical methods that can combine multivariate response variables into common measures of covariate effects have been proposed in the literature. Current methods for characterizing the relationship between covariates and the rate of change in multivariate outcomes are limited to select models. For example, 'accelerated time' methods have been developed which assume that covariates rescale time in longitudinal models for disease progression. In this manuscript, we detail an alternative multivariate model formulation that directly structures longitudinal rates of change and that permits a common covariate effect across multiple outcomes. We detail maximum likelihood estimation for a multivariate longitudinal mixed model. We show via asymptotic calculations the potential gain in power that may be achieved with a common analysis of multiple outcomes. We apply the proposed methods to the analysis of a trivariate outcome for infant growth and compare rates of change for HIV infected and uninfected infants. Copyright © 2016 John Wiley & Sons, Ltd.

  20. Bunched beam longitudinal instability: Coherent dipole motion

    SciTech Connect

    Zhang, S.Y.; Weng, W.T.

    1993-04-23

    In this paper, the authors present a new formulation for the longitudinal coherent dipole motion, where a quadrature response of the environmental impedance is shown to be the effective longitudinal impedance for the beam instability. The Robinson-Pedersen formulation for the longitudinal dipole motion is also presented, the difference of the two approaches is discussed in the comparison. The results by using the Sacherer integral equation for the coherent dipole motion can generate the same results as by using the other two approaches, except for a scaling difference. The formulation is further generalized to the rigid bunch motion using signal analysis method, where a form factor shows up naturally. Finally, the formulation is applied to solve the coupled bunch instabilities. Examples of the AGS Booster and the AGS coupled bunch instabilities are used to illustrate the applications of the formulation.

  1. Entanglement from longitudinal and scalar photons

    SciTech Connect

    Franson, J. D

    2011-09-15

    The covariant quantization of the electromagnetic field in the Lorentz gauge gives rise to longitudinal and scalar photons in addition to the usual transverse photons. It is shown here that the exchange of longitudinal and scalar photons can produce entanglement between two distant atoms or harmonic oscillators. The form of the entangled states produced in this way is very different from that obtained in the Coulomb gauge, where the longitudinal and scalar photons do not exist. A generalized gauge transformation is used to show that all physically observable effects are the same in the two gauges, despite the differences in the form of the entangled states. An approach of this kind may be useful for a covariant description of the dynamics of quantum information processing.

  2. Symmetric diffeomorphic modeling of longitudinal structural MRI.

    PubMed

    Ashburner, John; Ridgway, Gerard R

    2012-01-01

    This technology report describes the longitudinal registration approach that we intend to incorporate into SPM12. It essentially describes a group-wise intra-subject modeling framework, which combines diffeomorphic and rigid-body registration, incorporating a correction for the intensity inhomogeneity artifact usually seen in MRI data. Emphasis is placed on achieving internal consistency and accounting for many of the mathematical subtleties that most implementations overlook. The implementation was evaluated using examples from the OASIS Longitudinal MRI Data in Non-demented and Demented Older Adults.

  3. Symmetric Diffeomorphic Modeling of Longitudinal Structural MRI

    PubMed Central

    Ashburner, John; Ridgway, Gerard R.

    2013-01-01

    This technology report describes the longitudinal registration approach that we intend to incorporate into SPM12. It essentially describes a group-wise intra-subject modeling framework, which combines diffeomorphic and rigid-body registration, incorporating a correction for the intensity inhomogeneity artifact usually seen in MRI data. Emphasis is placed on achieving internal consistency and accounting for many of the mathematical subtleties that most implementations overlook. The implementation was evaluated using examples from the OASIS Longitudinal MRI Data in Non-demented and Demented Older Adults. PMID:23386806

  4. Disease Activity Score 28 (DAS28) using C-reactive protein underestimates disease activity and overestimates EULAR response criteria compared with DAS28 using erythrocyte sedimentation rate in a large observational cohort of rheumatoid arthritis patients in Japan.

    PubMed

    Matsui, Toshihiro; Kuga, Yoshiaki; Kaneko, Atsushi; Nishino, Jinju; Eto, Yoshito; Chiba, Noriyuki; Yasuda, Masayuki; Saisho, Koichiro; Shimada, Kota; Tohma, Shigeto

    2007-09-01

    To compare disease activity and the improvement of disease activity evaluated between by Disease Activity Score 28 using erythrocyte sedimentation rate (DAS28-ESR) and by DAS28 using C-reactive protein (DAS28-CRP) in Japanese patients with rheumatoid arthritis (RA). Data from 3073 RA patients registered in the large cohort database (NinJa: National Database of Rheumatic Diseases by iR-net in Japan) of 2003 was used to calculate DAS28-ESR and DAS28-CRP and disease activities were evaluated. Improvements in disease activities were also evaluated according to the European League Against Rheumatism (EULAR) response criteria in 1482 RA patients whose DAS28-ESR and DAS28-CRP could be calculated from data for both 2002 and 2003. The mean value of DAS28-CRP (3.59, SD 1.25) was significantly smaller than that of mean DAS28-ESR (4.31, SD 1.32) (p < 0.0001). The number of patients who satisfied the criteria of remission was 297 (9.7%) in DAS28-ESR versus 705 (22.9%) in DAS28-CRP and the number of patients with high disease activity was 842 (27.4%) versus 357 (11.6%) for DAS28-ESR and DAS28-CRP, respectively; there was a significant difference between the two (p < 0.0001). Change of respective DAS28 was significantly correlated (DeltaDAS28-ESR -0.05, SD 1.14 versus DeltaDAS28-CRP -0.10, SD 1.10) (p < 0.0001); however, the number of "good response" patients was significantly different (p < 0.03) between DAS28-ESR (97 patients, 6.5%) and DAS28-CRP (136 patients, 9.2%). DAS28-CRP significantly underestimated disease activity and overestimated the improvement in disease activity compared with DAS28-ESR. DAS28-CRP should be evaluated using different criteria from that for DAS28-ESR.

  5. What Can We Learn From Longitudinal Studies of Adult Development?

    PubMed Central

    Schaie, K. Warner

    2005-01-01

    This article distinguishes between normal and pathological aging, provides an interdisciplinary context, and then considers a sample case of cognitive aging. Developmental influences on cognition include the physiological infrastructure, genetic predispositions, and environmental influences. Different types of longitudinal studies are distinguished, and contrasting findings of cross-sectional and longitudinal are examined in the sample case of the Seattle Longitudinal Study. Also considered is the longitudinal context for intervention studies and the role of longitudinal family studies in assessing rate of aging and generational differences in rates of aging. Finally, attention is given to the role of longitudinal studies in the early detection of risk for dementia in advanced age. PMID:16467912

  6. Combined longitudinal and lateral control for automated vehicle guidance

    NASA Astrophysics Data System (ADS)

    Attia, Rachid; Orjuela, Rodolfo; Basset, Michel

    2014-02-01

    This paper deals with the longitudinal and lateral control of an automotive vehicle within the framework of fully automated guidance. The automotive vehicle is a complex system characterised by highly nonlinear longitudinal and lateral coupled dynamics. Consequently, automated guidance must be simultaneously performed with longitudinal and lateral control. This work presents an automated steering strategy based on nonlinear model predictive control. A nonlinear longitudinal control strategy considering powertrain dynamics is also proposed to cope with the longitudinal speed tracking problem. Finally, a simultaneous longitudinal and lateral control strategy helps to improve the combined control performance. This whole control strategy is tested through simulations showing the effectiveness of the present approach.

  7. Longitudinal magnetization loss in twisted multifilamentary Bi2223 tape

    NASA Astrophysics Data System (ADS)

    Amemiya, N.; Rabbers, J.-J.; Krooshoop, B. E.; ten Haken, B.; ten Kate, H.; Ayai, N.; Hayashi, K.

    2002-08-01

    Multifilamentary Bi2223 tapes are exposed to the longitudinal magnetic field as well as the transverse one in some electrical power apparatuses such as multilayer power transmission cables. Here, we define the longitudinal and transverse magnetic fields as the field components parallel and perpendicular to the tape axis, respectively. If the filament-bundle is twisted, it can couple to the AC longitudinal magnetic field to generate the longitudinal magnetization loss. Furthermore, the AC transport current flowing spirally in the twisted filament-bundle possibly influences the longitudinal magnetization. The longitudinal magnetization loss was measured in a twisted multifilamentary Bi2223 tape exposed to longitudinal magnetic field and carrying the transport current. The measured longitudinal magnetization loss in the twisted tape exposed to the longitudinal magnetic field is larger than that in another untwisted tape. Supplying the AC transport current changes the longitudinal magnetization loss in the twisted tape exposed to the AC longitudinal magnetic field. The influence of the transport current depends on the phase relation between the longitudinal magnetic field and the transport current. If their phase difference is 0°, the longitudinal magnetization loss decreases remarkably with increasing amplitude of the transport current. It means that the change in the current distribution due to the transport current results in the decrease in the power flow from the magnet power supply. But, a preliminary measurement of the transport loss shows that the total loss increases with increasing transport current.

  8. Biomechanics of Distance Running: A Longitudinal Study

    ERIC Educational Resources Information Center

    Nelson, Richard C.; Gregor, Robert J.

    1976-01-01

    Training for distance running over a long period produces meaningful changes in the running mechanics of experienced runners, as revealed in this longitudinal study of the biomechanical components of stride length, stride rate, stride time, and support and nonsupport time. (MB)

  9. Collaborative Knowledge-Building: A Longitudinal Study

    ERIC Educational Resources Information Center

    Li, Qing

    2009-01-01

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

  10. Biomechanics of Distance Running: A Longitudinal Study

    ERIC Educational Resources Information Center

    Nelson, Richard C.; Gregor, Robert J.

    1976-01-01

    Training for distance running over a long period produces meaningful changes in the running mechanics of experienced runners, as revealed in this longitudinal study of the biomechanical components of stride length, stride rate, stride time, and support and nonsupport time. (MB)

  11. Delinquency Prone Youth: Longitudinal and Preventive Research.

    ERIC Educational Resources Information Center

    Benning, James J.; And Others

    The first two phases of the EAU Claire County Youth Study were concerned with the relationships between classroom behavior and various facets of the child's family life. Phase II took two forms: (1) a major longitudinal evaluation of the relationships among classroom aggression, social adjustment, subsequent academic achievement, and juvenile…

  12. Managing Organizational Commitment: Insights from Longitudinal Research

    ERIC Educational Resources Information Center

    Morrow, Paula C.

    2011-01-01

    This article summarizes what is known about the "active" management of affective organizational commitment (AOC) through a review of 58 studies employing longitudinal research designs. The review yields six broad categories of antecedents that have empirically demonstrated effects on AOC: socialization practices, organizational changes, human…

  13. Teaching Technology Longitudinally to Virtual Children

    ERIC Educational Resources Information Center

    Matthews, Lynley

    2010-01-01

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

  14. Conducting Three-Level Longitudinal Analyses

    ERIC Educational Resources Information Center

    Peugh, James L.; Heck, Ronald H.

    2017-01-01

    Researchers in the field of early adolescence interested in quantifying the environmental influences on a response variable of interest over time would use cluster sampling (i.e., obtaining repeated measures from students nested within classrooms and/or schools) to obtain the needed sample size. The resulting longitudinal data would be nested at…

  15. Longitudinal Predictors of High School Completion

    ERIC Educational Resources Information Center

    Barry, Melissa; Reschly, Amy L.

    2012-01-01

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

  16. The Tevatron bunch by bunch longitudinal dampers

    SciTech Connect

    Cheng-Yang Tan and James Steimel

    2002-09-25

    We describe in this paper the Tevatron bunch by bunch dampers. The goal of the dampers is to stop the spontaneous longitudinal beam size blowup of the protons during a store. We will go through the theory and also show the measured results during the commissioning of this system. The system is currently operational and have stopped the beam blowups during a store.

  17. Religion and Aging in a Longitudinal Panel

    ERIC Educational Resources Information Center

    Blazer, Dan; Palmore, Erdman

    1976-01-01

    Analysis of religious activities and attitudes in a longitudinal panel of 272 community residents showed there were several significant and substantial correlations between religion and happiness, feelings of usefulness, and adjustment; these correlations also tended to be stronger for older persons and tended to increase over time. (Author)

  18. The Merits of Using Longitudinal Mediation

    ERIC Educational Resources Information Center

    Jose, Paul E.

    2016-01-01

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

  19. Issues in Longitudinal Research on Motivation

    ERIC Educational Resources Information Center

    Stoel, Reinoud D.; Roeleveld, Jaap; Peetsma, Thea; van den Wittenboer, Godfried; Hox, Joop

    2006-01-01

    This paper discusses two methodological issues regarding the analysis of longitudinal data using structural equation modeling that emerged during the reconsideration of the analysis of a recent study on the relationship between academic motivation and language achievement in elementary education [Stoel R.D., Peetsma, T.T.D. and Roeleveld, J.…

  20. The Merits of Using Longitudinal Mediation

    ERIC Educational Resources Information Center

    Jose, Paul E.

    2016-01-01

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

  1. MPCP Longitudinal Educational Growth Study Baseline Report

    ERIC Educational Resources Information Center

    Witte, John F.; Wolf, Patrick J.; Cowen, Joshua M.; Fleming, David J.; Lucas-McLean, Juanita

    2008-01-01

    This report focuses on the initial design, implementation and baseline results of the five-year Longitudinal Educational Growth Study (LEGS) of the Milwaukee Parental Choice Program (MPCP) being conducted by the School Choice Demonstration Project (SCDP). The LEGS will be the first evaluation of the participant effects of the MPCP using…

  2. Emotion Regulation and Childhood Aggression: Longitudinal Associations

    ERIC Educational Resources Information Center

    Roll, Judith; Koglin, Ute; Petermann, Franz

    2012-01-01

    Accumulating evidence suggests that emotion dysregulation is associated with psychopathology. This paper provides a review of recent longitudinal studies that investigate the relationship between emotion regulation and aggressive behavior in childhood age. While there is substantial evidence for assuming a close relation of emotion regulation and…

  3. Conducting Three-Level Longitudinal Analyses

    ERIC Educational Resources Information Center

    Peugh, James L.; Heck, Ronald H.

    2017-01-01

    Researchers in the field of early adolescence interested in quantifying the environmental influences on a response variable of interest over time would use cluster sampling (i.e., obtaining repeated measures from students nested within classrooms and/or schools) to obtain the needed sample size. The resulting longitudinal data would be nested at…

  4. Design and Implementation Issues in Longitudinal Research

    ERIC Educational Resources Information Center

    Ludlow, Larry H.; Pedulla, Joseph; Reagan, Emile Mitescu; Enterline, Sarah; Cannady, Mac; Chappe, Stephanie

    2011-01-01

    To meet demands for accountability, most schools and departments of education at institutions of higher education (IHEs) gather information on their current students and graduates. This paper describes issues to consider when designing a longitudinal data collection and management system, drawing on seven years' experience developing such a…

  5. Longitudinal Studies--Are They Worth It?

    ERIC Educational Resources Information Center

    Cowley, Judith

    A longitudinal study of otitis media in young children, begun in 1981, aimed to provide information on the incidence and prevalence of otitis media in young children in the Newcastle (England) region and to follow their academic progress. Subjects selected for the study were kindergartners in five schools and represented an ethnically homogeneous…

  6. An Early Intervention Project: A Longitudinal Look.

    ERIC Educational Resources Information Center

    Gordon, Ira J.

    This report describes the longitudinal research conducted in an early intervention program since 1966. The program is characterized by the use of paraprofessionals serving as home visitors and parent educators. Data collection has included measures of children's behavior and development, parent-child interactions, and parent variables such as…

  7. 14 CFR 23.145 - Longitudinal control.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Maneuverability § 23.145 Longitudinal control. (a) With the airplane as nearly as possible in trim at 1.3 VS1, it must be possible, at speeds below the trim speed, to pitch the nose downward so that the rate of increase in airspeed allows prompt acceleration to the trim speed with— (1) Maximum continuous power...

  8. 14 CFR 23.145 - Longitudinal control.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Maneuverability § 23.145 Longitudinal control. (a) With the airplane as nearly as possible in trim at 1.3 VS1, it must be possible, at speeds below the trim speed, to pitch the nose downward so that the rate of increase in airspeed allows prompt acceleration to the trim speed with— (1) Maximum continuous power...

  9. Longitudinal Predictors of High School Completion

    ERIC Educational Resources Information Center

    Barry, Melissa; Reschly, Amy L.

    2012-01-01

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

  10. Longitudinal photosynthetic gradient in crust lichens' thalli.

    PubMed

    Wu, Li; Zhang, Gaoke; Lan, Shubin; Zhang, Delu; Hu, Chunxiang

    2014-05-01

    In order to evaluate the self-shading protection for inner photobionts, the photosynthetic activities of three crust lichens were detected using Microscope-Imaging-PAM. The false color images showed that longitudinal photosynthetic gradient was found in both the green algal lichen Placidium sp. and the cyanolichen Peltula sp. In longitudinal direction, all the four chlorophyll fluorescence parameters Fv/Fm, Yield, qP, and rETR gradually decreased with depth in the thalli of both of these two lichens. In Placidium sp., qN values decreased with depth, whereas an opposite trend was found in Peltula sp. However, no such photosynthetic heterogeneity was found in the thalli of Collema sp. in longitudinal direction. Microscope observation showed that photobiont cells are compactly arranged in Placidium sp. and Peltula sp. while loosely distributed in Collema sp. It was considered that the longitudinal photosynthetic heterogeneity was ascribed to the result of gradual decrease of incidence caused by the compact arrangement of photobiont cells in the thalli. The results indicate a good protection from the self-shading for the inner photobionts against high radiation in crust lichens.

  11. Emotion Regulation and Childhood Aggression: Longitudinal Associations

    ERIC Educational Resources Information Center

    Roll, Judith; Koglin, Ute; Petermann, Franz

    2012-01-01

    Accumulating evidence suggests that emotion dysregulation is associated with psychopathology. This paper provides a review of recent longitudinal studies that investigate the relationship between emotion regulation and aggressive behavior in childhood age. While there is substantial evidence for assuming a close relation of emotion regulation and…

  12. Investigating Ceiling Effects in Longitudinal Data Analysis

    ERIC Educational Resources Information Center

    Wang, Lijuan; Zhang, Zhiyong; McArdle, John J.; Salthouse, Timothy A.

    2008-01-01

    Score limitation at the top of a scale is commonly termed "ceiling effect." Ceiling effects can lead to serious artifactual parameter estimates in most data analysis. This study examines the consequences of ceiling effects in longitudinal data analysis and investigates several methods of dealing with ceiling effects through Monte Carlo simulations…

  13. Preschool Fears: Longitudinal Sequence and Cohort Changes.

    ERIC Educational Resources Information Center

    Draper, Thomas W.; James, Rebecca Smoak

    1985-01-01

    Using longitudinal data gathered between 1966 and 1981, parent-reported fears of 49 university preschool children were examined with particular attention given to age changes and sex differences. Categories of types of fears reported by Jersild and Holmes (1933) determined a substantial increase in preschool children's fears of the dark, being…

  14. The National Longitudinal Surveys Handbook. Revised.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. Center for Human Resource Research.

    Designed as a comprehensive guide to the National Longitudinal Surveys of Labor Market Experience (NLS), this handbook is intended for two major categories of readers. For persons who wish to ascertain whether their research interests can be served by the NLS data, the handbook can provide the detailed description of the objectives of the surveys,…

  15. Are Sibling Relationships Protective? A Longitudinal Study

    ERIC Educational Resources Information Center

    Gass, Krista; Jenkins, Jennifer; Dunn, Judy

    2007-01-01

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

  16. Statistical Quality Control of Moisture Data in GEOS DAS

    NASA Technical Reports Server (NTRS)

    Dee, D. P.; Rukhovets, L.; Todling, R.

    1999-01-01

    A new statistical quality control algorithm was recently implemented in the Goddard Earth Observing System Data Assimilation System (GEOS DAS). The final step in the algorithm consists of an adaptive buddy check that either accepts or rejects outlier observations based on a local statistical analysis of nearby data. A basic assumption in any such test is that the observed field is spatially coherent, in the sense that nearby data can be expected to confirm each other. However, the buddy check resulted in excessive rejection of moisture data, especially during the Northern Hemisphere summer. The analysis moisture variable in GEOS DAS is water vapor mixing ratio. Observational evidence shows that the distribution of mixing ratio errors is far from normal. Furthermore, spatial correlations among mixing ratio errors are highly anisotropic and difficult to identify. Both factors contribute to the poor performance of the statistical quality control algorithm. To alleviate the problem, we applied the buddy check to relative humidity data instead. This variable explicitly depends on temperature and therefore exhibits a much greater spatial coherence. As a result, reject rates of moisture data are much more reasonable and homogeneous in time and space.

  17. Statistical Quality Control of Moisture Data in GEOS DAS

    NASA Technical Reports Server (NTRS)

    Dee, D. P.; Rukhovets, L.; Todling, R.

    1999-01-01

    A new statistical quality control algorithm was recently implemented in the Goddard Earth Observing System Data Assimilation System (GEOS DAS). The final step in the algorithm consists of an adaptive buddy check that either accepts or rejects outlier observations based on a local statistical analysis of nearby data. A basic assumption in any such test is that the observed field is spatially coherent, in the sense that nearby data can be expected to confirm each other. However, the buddy check resulted in excessive rejection of moisture data, especially during the Northern Hemisphere summer. The analysis moisture variable in GEOS DAS is water vapor mixing ratio. Observational evidence shows that the distribution of mixing ratio errors is far from normal. Furthermore, spatial correlations among mixing ratio errors are highly anisotropic and difficult to identify. Both factors contribute to the poor performance of the statistical quality control algorithm. To alleviate the problem, we applied the buddy check to relative humidity data instead. This variable explicitly depends on temperature and therefore exhibits a much greater spatial coherence. As a result, reject rates of moisture data are much more reasonable and homogeneous in time and space.

  18. Einfluss des Internets auf das Informations-, Einkaufs- und Verkehrsverhalten

    NASA Astrophysics Data System (ADS)

    Nerlich, Mark R.; Schiffner, Felix; Vogt, Walter

    Mit Daten aus eigenen Erhebungen können das einkaufsbezogene Informations- und Einkaufsverhalten im Zusammenhang mit den verkehrlichen Aspekten (Distanzen, Verkehrsmittel, Wegekopplungen) dargestellt werden. Die Differenzierung in die drei Produktkategorien des täglichen, mittelfristigen und des langfristigen Bedarfs berücksichtigt in erster Linie die Wertigkeit eines Gutes, die seine Erwerbshäufigkeit unmittelbar bestimmt. Der Einsatz moderner IKT wie das Internet eröffnet dem Endverbraucher neue Möglichkeiten bei Information und Einkauf. Die verkehrliche Relevanz von Online-Shopping wird deutlich, wenn man berücksichtigt, dass im Mittel rund 17% aller Online-Einkäufe, die die Probanden durchgeführt haben, Einkäufe in Ladengeschäften ersetzen. Dies gilt in verstärktem Maße für Online-Informationen: etwa die Hälfte hätte alternativ im stationären Einzelhandel stattgefunden. Da der Erwerb von Gütern des täglichen Bedarfs häufig nahräumlich und in relevantem Anteil nicht-motorisiert erfolgen kann, sind in diesem Segment - im Gegensatz zum mittel- und langfristigen Bedarf - nur geringe Substitutionseffekte zu beobachten.

  19. Titan's Longitudinal Dunes in the Lab.

    NASA Astrophysics Data System (ADS)

    Reffet, Erwan; Courrech du Pont, S.; Hersen, P.; Douady, S.; Radebaugh, J.; Lorenz, R.; Lunine, J.; Boubin, G.; Fulchignoni, M.

    2007-10-01

    Cassini Radar observations of Titan's surface have revealed various landscapes. In particular, flybys probing Titan's equator unveiled linear features [1], which are morphologically similar to longitudinal dunes [2,3]. They appear pervasive in the range +-30° in latitude and could cover up to 20% of Titan's surface [4]. Their characteristics in term of width, length and spacing [1,4,5], or height and slope [6] are comparable to dunes of the Namib Desert [2]. On Earth, longitudinal dunes are the most commonly encountered dune and are observed in regions where the wind regime is composed of two main directions, the dunes orientation giving the mean sand transport. While terrestrial dunes are mostly formed by quartz sand grains, Titan's dunes are likely to be composed of hydrocarbon particulates [7]. Despite their different compositions, their morphological resemblances suggest similar processes of formation. Thus studying the formation of such structures could help to constrain models of Titan's winds [8]. However, formation of longitudinal dunes or even more generally longitudinal bedforms [9] have rarely been observed or reproduced in controlled conditions. Underwater experiments, in which sand transport timescale and lengthscale are decreased, have been used to successfully reproduce the dynamics of barchan dunes [10]. We show here how it is possible to explore the morphogenesis of longitudinal dunes using such a method combined with a numerical model. References: [1] Boubin et al. DPS 2005. [2] Lorenz et al. LPSC 2006. [3] Lorenz et al. Science 2006. [4] Radebaugh et al. Icarus (in revision). [5] Radebaugh et al. LPSC 2006. [6] Kirk et al. LPSC 2005. [7] Soderblom et al. P&SS (in press). [8] Tokano et al. Icarus 2002. [9] Rubin et al. Science 1987. [10] Hersen et al. PRL, 2003.

  20. Using the Longitudinal Study as a Central Teaching Focus.

    ERIC Educational Resources Information Center

    Demchik, Michael J.

    1999-01-01

    Argues that treatment of one investigative longitudinal topic from start to finish in a high school biology class can illustrate many major ideas and concepts. Discusses ways to use various longitudinal studies of plant growth with General Biology classes. (WRM)

  1. 115. DETAILS OF REINFORCEMENT: TYPICAL CROSSSECTION, LONGITUDINAL BRACE OF CENTER ...

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

    115. DETAILS OF REINFORCEMENT: TYPICAL CROSS-SECTION, LONGITUDINAL BRACE OF CENTER PILES, OUTSIDE LONGITUDINAL GIRDER Sheet 6 of 9 (#3257) - Huntington Beach Municipal Pier, Pacific Coast Highway at Main Street, Huntington Beach, Orange County, CA

  2. Um estudo espectrofotométrico da variável cataclísmica V3885 Sgr

    NASA Astrophysics Data System (ADS)

    Ribeiro, F. M. A.; Diaz, M. P.

    2003-08-01

    Variáveis Cataclísmicas são sistemas binários cerrados compostos de uma anã vermelha que transfere matéria para uma anã branca, em sistemas não magnéticos ocorre a formação de um disco de acresção em torno da anã branca. V3885 Sgr é uma variável cataclísmica classificada como sendo do tipo nova-like. É apresentado um estudo espectrofotométrico de V3885 Sgr de alta resolução temporal feito na região do visível. A região observada é centrada em Ha e abrange também a linha de HeI 6678. O primeiro resultado obtido neste estudo é a determinação do período orbital a partir de medidas da velocidade radial da linha de Ha como sendo 0,20716071(22) dias, resolvendo inconsistências quanto a esse valor na literatura e definindo uma efeméride a longo prazo para o sistema. Com este período e as medidas de velocidade radial do perfil de linha de Ha foi construído um diagrama de massas, através do qual restringimos as massas das componentes estelares do sistema e limitamos a inclinação orbital do sistema. Foram construídos diagramas de Greenstein para as linhas de Ha e HeI, onde os espectros médios em cada intervalo de fase são representados lado a lado em escala de cinza, indicando a existência de uma emissão intensa proveniente da parte posterior do disco. A partir da tomografia Doppler obtivemos perfis de emissividade radial para o disco tanto para a linha de Ha como para HeI. Os resultados obtidos são comparados com os de outros sistemas estudados com a mesma técnica. Serão apresentados também resultados da tomografia de flickering para o sistema.

  3. Longitudinal Multitrait-Multimethod Models for Developmental Research

    ERIC Educational Resources Information Center

    Grimm, Kevin J.; Pianta, Robert C.; Konold, Timothy

    2009-01-01

    Multitrait-multimethod (MTMM) confirmatory factor models were combined with longitudinal structural equation models to examine trait and method stability over time. A longitudinal correlated-trait correlated-method (CT-CM) model allowed for the study of trait and method variance in observed scores over time. Longitudinal measurement invariance was…

  4. 14 CFR 29.173 - Static longitudinal stability.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Static longitudinal stability. 29.173 Section 29.173 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Static longitudinal stability. (a) The longitudinal control must be designed so that a rearward...

  5. 49 CFR 238.405 - Longitudinal static compressive strength.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Longitudinal static compressive strength. 238.405... II Passenger Equipment § 238.405 Longitudinal static compressive strength. (a) To form an effective... shall resist a minimum longitudinal static compressive force of 2,100,000 pounds without...

  6. 14 CFR 29.173 - Static longitudinal stability.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Static longitudinal stability. 29.173 Section 29.173 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Static longitudinal stability. (a) The longitudinal control must be designed so that a rearward...

  7. 14 CFR 23.175 - Demonstration of static longitudinal stability.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Demonstration of static longitudinal stability. 23.175 Section 23.175 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Flight Stability § 23.175 Demonstration of static longitudinal stability. Static longitudinal...

  8. 14 CFR 23.175 - Demonstration of static longitudinal stability.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Demonstration of static longitudinal stability. 23.175 Section 23.175 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Flight Stability § 23.175 Demonstration of static longitudinal stability. Static longitudinal...

  9. 49 CFR 238.405 - Longitudinal static compressive strength.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Longitudinal static compressive strength. 238.405... II Passenger Equipment § 238.405 Longitudinal static compressive strength. (a) To form an effective... shall resist a minimum longitudinal static compressive force of 2,100,000 pounds without...

  10. 49 CFR 238.405 - Longitudinal static compressive strength.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Longitudinal static compressive strength. 238.405... II Passenger Equipment § 238.405 Longitudinal static compressive strength. (a) To form an effective... shall resist a minimum longitudinal static compressive force of 2,100,000 pounds without...

  11. 49 CFR 238.405 - Longitudinal static compressive strength.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Longitudinal static compressive strength. 238.405... II Passenger Equipment § 238.405 Longitudinal static compressive strength. (a) To form an effective... shall resist a minimum longitudinal static compressive force of 2,100,000 pounds without...

  12. 14 CFR 23.175 - Demonstration of static longitudinal stability.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Demonstration of static longitudinal stability. 23.175 Section 23.175 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Flight Stability § 23.175 Demonstration of static longitudinal stability. Static longitudinal...

  13. 14 CFR 29.173 - Static longitudinal stability.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Static longitudinal stability. 29.173 Section 29.173 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Static longitudinal stability. (a) The longitudinal control must be designed so that a rearward...

  14. 14 CFR 23.175 - Demonstration of static longitudinal stability.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Demonstration of static longitudinal stability. 23.175 Section 23.175 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Flight Stability § 23.175 Demonstration of static longitudinal stability. Static longitudinal...

  15. 49 CFR 238.405 - Longitudinal static compressive strength.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Longitudinal static compressive strength. 238.405... II Passenger Equipment § 238.405 Longitudinal static compressive strength. (a) To form an effective... shall resist a minimum longitudinal static compressive force of 2,100,000 pounds without...

  16. 14 CFR 23.175 - Demonstration of static longitudinal stability.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Demonstration of static longitudinal stability. 23.175 Section 23.175 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Flight Stability § 23.175 Demonstration of static longitudinal stability. Static longitudinal...

  17. 14 CFR 29.173 - Static longitudinal stability.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Static longitudinal stability. 29.173 Section 29.173 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Static longitudinal stability. (a) The longitudinal control must be designed so that a rearward...

  18. 14 CFR 29.173 - Static longitudinal stability.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Static longitudinal stability. 29.173 Section 29.173 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Static longitudinal stability. (a) The longitudinal control must be designed so that a rearward...

  19. 46 CFR 154.176 - Longitudinal contiguous hull structure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

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

  20. M-DAS: System for multispectral data analysis. [in Saginaw Bay, Michigan

    NASA Technical Reports Server (NTRS)

    Johnson, R. H.

    1975-01-01

    M-DAS is a ground data processing system designed for analysis of multispectral data. M-DAS operates on multispectral data from LANDSAT, S-192, M2S and other sources in CCT form. Interactive training by operator-investigators using a variable cursor on a color display was used to derive optimum processing coefficients and data on cluster separability. An advanced multivariate normal-maximum likelihood processing algorithm was used to produce output in various formats: color-coded film images, geometrically corrected map overlays, moving displays of scene sections, coverage tabulations and categorized CCTs. The analysis procedure for M-DAS involves three phases: (1) screening and training, (2) analysis of training data to compute performance predictions and processing coefficients, and (3) processing of multichannel input data into categorized results. Typical M-DAS applications involve iteration between each of these phases. A series of photographs of the M-DAS display are used to illustrate M-DAS operation.

  1. M-DAS: System for multispectral data analysis. [in Saginaw Bay, Michigan

    NASA Technical Reports Server (NTRS)

    Johnson, R. H.

    1975-01-01

    M-DAS is a ground data processing system designed for analysis of multispectral data. M-DAS operates on multispectral data from LANDSAT, S-192, M2S and other sources in CCT form. Interactive training by operator-investigators using a variable cursor on a color display was used to derive optimum processing coefficients and data on cluster separability. An advanced multivariate normal-maximum likelihood processing algorithm was used to produce output in various formats: color-coded film images, geometrically corrected map overlays, moving displays of scene sections, coverage tabulations and categorized CCTs. The analysis procedure for M-DAS involves three phases: (1) screening and training, (2) analysis of training data to compute performance predictions and processing coefficients, and (3) processing of multichannel input data into categorized results. Typical M-DAS applications involve iteration between each of these phases. A series of photographs of the M-DAS display are used to illustrate M-DAS operation.

  2. Das Assessment von Vulnerabilitäten, Risiken und Unsicherheiten

    NASA Astrophysics Data System (ADS)

    Birkmann, Jörn; Greiving, Stefan; Serdeczny, Olivia Maria

    Die Risiken und möglichen Folgen des Klimawandels für Menschen, Produktions- und Ökosysteme sind eng mit sozioökonomischen Entwicklungen und Rahmenbedingungen verflochten. Die Schlüsselbegriffe "Vulnerabilität", "Risiko" und "Unsicherheit" werden näher beleuchtet, um u. a. deutlich zu machen, wie sie im neueren Risikoansatz des Fünften Sachstandsberichts (AR5) des Weltklimarats (IPCC) genutzt werden. Das Risikokonzept wird vom Vulnerabilitätskonzept unterschieden. In den Fokus rückt die Betrachtung von Gefahr und Exposition. Auch die Frage, was unter Unsicherheit und Bandbreiten möglicher Entwicklungen des Klimas und sogenannter sozioökonomischer Entwicklungspfade zu verstehen ist, spielt dabei eine wichtige Rolle. Bisherige Untersuchungsmethoden zu Risiken im Kontext des Klimawandels und darauf aufbauende Entscheidungsprozesse werden im Hinblick auf künftige Anpassungsmaßnahmen diskutiert.

  3. Das Semantic Web als Werkzeug in der biomedizinischen Forschung

    NASA Astrophysics Data System (ADS)

    Stenzhorn, Holger; Samwald, Matthias

    In der biomedizinischen Forschung werden besonders in den letzten Jahren vermehrt enorme Mengen an neuen Daten produziert und diese in Folge verstärkt per Internet veröffentlicht. Viele Experten sehen in dieser Vorgehensweise die Chance zur Entdeckung bisher unbekannter biomedizinischer Erkenntnisse. Um dies jedoch zu ermöglichen, müssen neue Wege gefunden werden, die gewonnenen Daten effizient zu verarbeiten und zu verwalten. In dem vorliegenden Artikel werden die Möglichkeiten betrachtet, die das Semantic Web hierzu anbieten kann. Hierfür werden die relevanten Technologien des Semantic Web im speziellen Kontext der biomedizinischen Forschung betrachtet. Ein Fokus liegt auf der Anwendung von Ontologien in der Biomedizin: Es wird auf deren Vorteile eingegangen, aber auch auf möglichen Probleme, die deren Einsatz in einem erweiterten wissenschaftlichen Umfeld mit sich bringen können.

  4. A 2-D numerical simulation study on longitudinal solute transport and longitudinal dispersion coefficient

    NASA Astrophysics Data System (ADS)

    Zhang, Wei

    2011-07-01

    The longitudinal dispersion coefficient, DL, is a fundamental parameter of longitudinal solute transport models: the advection-dispersion (AD) model and various deadzone models. Since DL cannot be measured directly, and since its calibration using tracer test data is quite expensive and not always available, researchers have developed various methods, theoretical or empirical, for estimating DL by easier available cross-sectional hydraulic measurements (i.e., the transverse velocity profile, etc.). However, for known and unknown reasons, DL cannot be satisfactorily predicted using these theoretical/empirical formulae. Either there is very large prediction error for theoretical methods, or there is a lack of generality for the empirical formulae. Here, numerical experiments using Mike21, a software package that implements one of the most rigorous two-dimensional hydrodynamic and solute transport equations, for longitudinal solute transport in hypothetical streams, are presented. An analysis of the evolution of simulated solute clouds indicates that the two fundamental assumptions in Fischer's longitudinal transport analysis may be not reasonable. The transverse solute concentration distribution, and hence the longitudinal transport appears to be controlled by a dimensionless number ?, where Q is the average volumetric flowrate, Dt is a cross-sectional average transverse dispersion coefficient, and W is channel flow width. A simple empirical ? relationship may be established. Analysis and a revision of Fischer's theoretical formula suggest that ɛ influences the efficiency of transverse mixing and hence has restraining effect on longitudinal spreading. The findings presented here would improve and expand our understanding of longitudinal solute transport in open channel flow.

  5. Longitudinal Trajectories of Cigarette Smoking Following Rape

    PubMed Central

    Amstadter, Ananda B.; Resnick, Heidi S.; Nugent, Nicole R.; Acierno, Ron; Rheingold, Alyssa A.; Minhinnett, Robin; Kilpatrick, Dean G.

    2009-01-01

    Although prior research has identified increases in cigarette smoking following trauma exposure, no studies have examined longitudinal trajectories of smoking following rape. The present investigation identifies and characterizes longitudinal (< 3 months, 3-6 months, and > 6 months post-assault) trajectories of smoking (N = 152) following a rape in a sample of 268 sexual assault victims participating in a forensic medical exam. Further, we examine acute predictors of subsequent smoking trajectories. Of participants endorsing smoking post-rape, a two-class solution was identified, with the majority of participants (74.6%) evidencing moderate smoking with a slight decrease over time and remaining participants showing heavy smoking with a slight increase over time. Having sustained an injury, minority status, and post-exam distress all predicted subsequent smoking trajectory. PMID:19370699

  6. Longitudinal variations of the equatorial electojet

    NASA Astrophysics Data System (ADS)

    Shume, Esayas

    We have utilized a three dimensional electrostatic potential model to explain the longitudinal variations of the equatorial electrojet. The model runs were constrained by net H component magnetic field measurements from three equatorial stations, namely, Huancayo (Peru) 12.05 S, 284.67 E; Addis Ababa (Ethiopia) 9.8 N, 38.8 E; Tirunelveli (India) 8.42 N, 77.48 E. The model runs were done in an iterative fashion until the computed and measured H component magnetic field values come into a close agreement. The physical mechanisms for the longitudinal variations of the equatorial electrojet were inferred by comparing and contrasting the resulting computed vertical polarization electric field (which drives the equatorial electrojet), and zonal current density profiles for the three stations mentioned above.

  7. Linac Coherent Light Source Longitudinal Feedback Model

    SciTech Connect

    Wu, Juhao; Emma, P.; Hendrickson, L.; /SLAC

    2005-06-15

    The Linac Coherent Light Source (LCLS) will be the world's first x-ray free-electron laser (FEL). To ensure the vitality of FEL lasing, it is critical to preserve the high quality of the electron beam during acceleration and compression. The peak current and final energy are very sensitive to system jitter. To minimize this sensitivity, a longitudinal feedback system on the bunch length and energy is required, together with other diagnostics and feedback systems (e.g., on transverse phase space). Here, we describe a simulation framework, which includes a realistic jitter model for the LCLS accelerator system, the RF acceleration, structure wakefield, and second order optics. Simulation results show that to meet the tight requirements set by the FEL, such a longitudinal feedback system is mandatory.

  8. Left ventricular longitudinal strain in soccer referees.

    PubMed

    Gianturco, Luigi; Bodini, Bruno; Gianturco, Vincenzo; Lippo, Giuseppina; Solbiati, Agnese; Turiel, Maurizio

    2017-02-09

    Along the years, the analysis of soccer referees perfomance has interested the experts and we can find several types of studies in literature using in particular cardiac imaging. The aim of this retrospective study was to observe relationship between VO2max uptake and some conventional and not-conventional echocardiographic parameters. In order to perform this evaluation, we have enrolled 20 referees, belonging to Italian Soccer Referees' Association and we have investigated cardiovascular profile of them. We found a strong direct relationship between VO2max and global longitudinal strain of left ventricle assessed by means of speckle tracking echocardiographic analysis (R2=0.8464). The most common classic echocardiographic indexes have showed mild relations (respectively, VO2max vs EF: R2=0.4444; VO2max vs LV indexed mass: R2=0.2268). Therefore, our study suggests that longitudinal strain could be proposed as a specific echocardiographic parameter to evaluate the soccer referees performance.

  9. A longitudinal analysis of teenage drinking patterns.

    PubMed

    Shahtahmasebi, Said; Berridge, Damon

    2009-01-01

    This paper examines the multinomial recurrent outcome 'teenage drinking' within a statistical modeling paradigm. The proposed statistical modeling relates drinking to a set of explanatory variables, which include subjective as well as objective measures. In order to assess the degree to which explanatory variables influence smoking, an adequate statistical model must handle the possibility that substantial variation between respondents will be due to omitted variables, multicollinearity and past behavior. To address these issues, longitudinal data using appropriate statistical modeling are essential. In this paper we demonstrate the application of appropriate longitudinal modeling using data from the Yorkshire (UK) Health Related Behavior Questionnaire. The results suggest there may be substantial heterogeneity due to omitted variables in the data and complex inter-relationships between observed explanatory variables. For example, social cultures of drinking and parental involvement appear to influence heavy drinking and drug use.

  10. Left ventricular longitudinal strain in soccer referees

    PubMed Central

    Gianturco, Luigi; Bodini, Bruno; Gianturco, Vincenzo; Lippo, Giuseppina; Solbiati, Agnese; Turiel, Maurizio

    2017-01-01

    Along the years, the analysis of soccer referees perfomance has interested the experts and we can find several types of studies in literature using in particular cardiac imaging. The aim of this retrospective study was to observe relationship between VO2max uptake and some conventional and not-conventional echocardiographic parameters. In order to perform this evaluation, we have enrolled 20 referees, belonging to Italian Soccer Referees' Association and we have investigated cardiovascular profile of them. We found a strong direct relationship between VO2max and global longitudinal strain of left ventricle assessed by means of speckle tracking echocardiographic analysis (R2=0.8464). The most common classic echocardiographic indexes have showed mild relations (respectively, VO2max vs EF: R2=0.4444; VO2max vs LV indexed mass: R2=0.2268). Therefore, our study suggests that longitudinal strain could be proposed as a specific echocardiographic parameter to evaluate the soccer referees performance. PMID:28199991

  11. Longitudinal multiple sclerosis lesion segmentation data resource.

    PubMed

    Carass, Aaron; Roy, Snehashis; Jog, Amod; Cuzzocreo, Jennifer L; Magrath, Elizabeth; Gherman, Adrian; Button, Julia; Nguyen, James; Bazin, Pierre-Louis; Calabresi, Peter A; Crainiceanu, Ciprian M; Ellingsen, Lotta M; Reich, Daniel S; Prince, Jerry L; Pham, Dzung L

    2017-06-01

    The data presented in this article is related to the research article entitled "Longitudinal multiple sclerosis lesion segmentation: Resource and challenge" (Carass et al., 2017) [1]. In conjunction with the 2015 International Symposium on Biomedical Imaging, we organized a longitudinal multiple sclerosis (MS) lesion segmentation challenge providing training and test data to registered participants. The training data consists of five subjects with a mean of 4.4 (±0.55) time-points, and test data of fourteen subjects with a mean of 4.4 (±0.67) time-points. All 82 data sets had the white matter lesions associated with multiple sclerosis delineated by two human expert raters. The training data including multi-modal scans and manually delineated lesion masks is available for download. In addition, the testing data is also being made available in conjunction with a website for evaluating the automated analysis of the testing data.

  12. Multivariate Longitudinal Analysis with Bivariate Correlation Test.

    PubMed

    Adjakossa, Eric Houngla; Sadissou, Ibrahim; Hounkonnou, Mahouton Norbert; Nuel, Gregory

    2016-01-01

    In the context of multivariate multilevel data analysis, this paper focuses on the multivariate linear mixed-effects model, including all the correlations between the random effects when the dimensional residual terms are assumed uncorrelated. Using the EM algorithm, we suggest more general expressions of the model's parameters estimators. These estimators can be used in the framework of the multivariate longitudinal data analysis as well as in the more general context of the analysis of multivariate multilevel data. By using a likelihood ratio test, we test the significance of the correlations between the random effects of two dependent variables of the model, in order to investigate whether or not it is useful to model these dependent variables jointly. Simulation studies are done to assess both the parameter recovery performance of the EM estimators and the power of the test. Using two empirical data sets which are of longitudinal multivariate type and multivariate multilevel type, respectively, the usefulness of the test is illustrated.

  13. A Sparse Bayesian Learning Algorithm for Longitudinal Image Data.

    PubMed

    Sabuncu, Mert R

    2015-10-01

    Longitudinal imaging studies, where serial (multiple) scans are collected on each individual, are becoming increasingly widespread. The field of machine learning has in general neglected the longitudinal design, since many algorithms are built on the assumption that each datapoint is an independent sample. Thus, the application of general purpose machine learning tools to longitudinal image data can be sub-optimal. Here, we present a novel machine learning algorithm designed to handle longitudinal image datasets. Our approach builds on a sparse Bayesian image-based prediction algorithm. Our empirical results demonstrate that the proposed method can offer a significant boost in prediction performance with longitudinal clinical data.

  14. Nonlinear longitudinal control of a supermaneuverable aircraft

    NASA Technical Reports Server (NTRS)

    Garrard, William L.; Snell, Anthony; Enns, Dale F.

    1989-01-01

    A technique is described which can be used for design of feedback controllers for high-performance aircraft operating in flight conditions in which nonlinearities significantly affect performance. Designs are performed on a mathematical model of the longitudinal dynamics of a hypothetical aircraft similar to proposed supermaneuverable flight test vehicles. Nonlinear controller designs are performed using truncated solutions of the Hamilton-Jacobi-Bellman equation. Preliminary results show that the method yields promising results.

  15. Nonlinear longitudinal control of a supermaneuverable aircraft

    NASA Technical Reports Server (NTRS)

    Garrard, William L.; Snell, Anthony; Enns, Dale F.

    1989-01-01

    A technique is described which can be used for design of feedback controllers for high-performance aircraft operating in flight conditions in which nonlinearities significantly affect performance. Designs are performed on a mathematical model of the longitudinal dynamics of a hypothetical aircraft similar to proposed supermaneuverable flight test vehicles. Nonlinear controller designs are performed using truncated solutions of the Hamilton-Jacobi-Bellman equation. Preliminary results show that the method yields promising results.

  16. Marginal longitudinal semiparametric regression via penalized splines

    PubMed Central

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

    2010-01-01

    We study the marginal longitudinal nonparametric regression problem and some of its semiparametric extensions. We point out that, while several elaborate proposals for efficient estimation have been proposed, a relative simple and straightforward one, based on penalized splines, has not. After describing our approach, we then explain how Gibbs sampling and the BUGS software can be used to achieve quick and effective implementation. Illustrations are provided for nonparametric regression and additive models. PMID:21037941

  17. Moving Block Bootstrap for Analyzing Longitudinal Data

    PubMed Central

    Ju, Hyunsu

    2015-01-01

    In a longitudinal study subjects are followed over time. I focus on a case where the number of replications over time is large relative to the number of subjects in the study. I investigate the use of moving block bootstrap methods for analyzing such data. Asymptotic properties of the bootstrap methods in this setting are derived. The effectiveness of these resampling methods is also demonstrated through a simulation study. PMID:26023251

  18. Anterior longitudinal aortotomy in aortic valve replacement.

    PubMed

    Matsuzaki, Kanji; Kudo, Yohei; Ikeda, Akihiko; Konishi, Taisuke; Jikuya, Tomoaki

    2016-02-01

    We adopted an anterior longitudinal aortotomy in some cases of aortic valve replacement (AVR), and report them here. The potential of this method is also discussed. We analyzed the data on 24 patients (75.5 ± 7.8 years of age) who had undergone AVR through anterior longitudinal aortotomy. The indications for surgery were prosthetic valve complication in 5 patients, aortic stenosis (AS) with left ventricular outflow tract stenosis (LVOTS) in 16 patients, and aortic regurgitation with moderately dilated ascending aorta in 3 patients. The Konno procedure was performed in 6 cases with small aortic annuli. A longitudinal aortotomy was made at the aortic root along the left side of the right coronary ostium, and extended beyond the right coronary annulus to the interventricular septum as needed. Bioprostheses (21.1 ± 1.7 mm) were used in 23 patients and a 21-mm mechanical valve for one (a 59-year-old man). One high-risk patient died of low output syndrome, leading to a mortality rate of 4.2 %. All other patients recovered well, though atrioventricular block occurred in 2 cases. Anterior longitudinal aortotomy provides a good field of vision at the aortic annulus and the flexibility to develop into anterior annular enlargement. Major indications for this approach are small sino-tubular junction and very small aortic annulus. This approach could be an attractive option in AVR for cases of AS with small aortic annuli and LVOTS. It could also be useful for AVR cases with moderately dilated ascending aorta requiring aortoplasty.

  19. Predictors of Transfer Adjustment: A Longitudinal Study.

    DTIC Science & Technology

    1985-01-01

    Department of Psychology . : PREDICTORS OF TRANSFER AIIJUSTNEN: . A LONGITUDIN4AL STUDY"- Jaues B. Shaw Cynthia D. Fisher and Richard W. Woodman...1985 Acssa o NTIS GRA&I TR-ONR-7 DTIC TAB Unannounced E Just ification Distribution/ Department of Psychology Availability Codes Department of...PROJECT. TASKAREA & WORK UNIT NUMIBERS Departments of Management and Psychology 62763 N Texas.A&M University RF 63521 College Station, TX 77843 RF

  20. RADON reconstruction in longitudinal phase space

    SciTech Connect

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

    1997-07-01

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

  1. CLADA: cortical longitudinal atrophy detection algorithm.

    PubMed

    Nakamura, Kunio; Fox, Robert; Fisher, Elizabeth

    2011-01-01

    Measurement of changes in brain cortical thickness is useful for the assessment of regional gray matter atrophy in neurodegenerative conditions. A new longitudinal method, called CLADA (cortical longitudinal atrophy detection algorithm), has been developed for the measurement of changes in cortical thickness in magnetic resonance images (MRI) acquired over time. CLADA creates a subject-specific cortical model which is longitudinally deformed to match images from individual time points. The algorithm was designed to work reliably for lower resolution images, such as the MRIs with 1×1×5 mm(3) voxels previously acquired for many clinical trials in multiple sclerosis (MS). CLADA was evaluated to determine reproducibility, accuracy, and sensitivity. Scan-rescan variability was 0.45% for images with 1mm(3) isotropic voxels and 0.77% for images with 1×1×5 mm(3) voxels. The mean absolute accuracy error was 0.43 mm, as determined by comparison of CLADA measurements to cortical thickness measured directly in post-mortem tissue. CLADA's sensitivity for correctly detecting at least 0.1mm change was 86% in a simulation study. A comparison to FreeSurfer showed good agreement (Pearson correlation=0.73 for global mean thickness). CLADA was also applied to MRIs acquired over 18 months in secondary progressive MS patients who were imaged at two different resolutions. Cortical thinning was detected in this group in both the lower and higher resolution images. CLADA detected a higher rate of cortical thinning in MS patients compared to healthy controls over 2 years. These results show that CLADA can be used for reliable measurement of cortical atrophy in longitudinal studies, even in lower resolution images.

  2. CLADA: Cortical Longitudinal Atrophy Detection Algorithm

    PubMed Central

    Nakamura, Kunio; Fox, Robert; Fisher, Elizabeth

    2010-01-01

    Measurement of changes in brain cortical thickness is useful for assessment of regional gray matter atrophy in neurodegenerative conditions. A new longitudinal method, called CLADA (cortical longitudinal atrophy detection algorithm), has been developed for measurement of changes in cortical thickness in magnetic resonance images (MRI) acquired over time. CLADA creates a subject-specific cortical model which is longitudinally deformed to match images from individual time points. The algorithm was designed to work reliably for lower-resolution images, such as the MRIs with 1×1×5mm3 voxels previously acquired for many clinical trials in multiple sclerosis (MS). CLADA was evaluated to determine reproducibility, accuracy, and sensitivity. Scan-rescan variability was 0.45% for images with 1mm3 isotropic voxels and 0.77% for images with 1×1×5 mm3 voxels. The mean absolute accuracy error was 0.43 mm, as determined by comparison of CLADA measurements to cortical thickness measured directly in post- mortem tissue. CLADA’s sensitivity for correctly detecting at least 0.1 mm change was 86% in a simulation study. A comparison to FreeSurfer showed good agreement (Pearson correlation = 0.73 for global mean thickness). CLADA was also applied to MRIs acquired over 18 months in secondary progressive MS patients who were imaged at two different resolutions. Cortical thinning was detected in this group in both the lower and higher resolution images. CLADA detected a higher rate of cortical thinning in MS patients compared to healthy controls over 2 years. These results show that CLADA can be used for reliable measurement of cortical atrophy in longitudinal studies, even in lower resolution images. PMID:20674750

  3. Moving Block Bootstrap for Analyzing Longitudinal Data.

    PubMed

    Ju, Hyunsu

    In a longitudinal study subjects are followed over time. I focus on a case where the number of replications over time is large relative to the number of subjects in the study. I investigate the use of moving block bootstrap methods for analyzing such data. Asymptotic properties of the bootstrap methods in this setting are derived. The effectiveness of these resampling methods is also demonstrated through a simulation study.

  4. PREPROCESSING MAGNETIC FIELDS WITH CHROMOSPHERIC LONGITUDINAL FIELDS

    SciTech Connect

    Yamamoto, Tetsuya T.; Kusano, K.

    2012-06-20

    Nonlinear force-free field (NLFFF) extrapolation is a powerful tool for the modeling of the magnetic field in the solar corona. However, since the photospheric magnetic field does not in general satisfy the force-free condition, some kind of processing is required to assimilate data into the model. In this paper, we report the results of new preprocessing for the NLFFF extrapolation. Through this preprocessing, we expect to obtain magnetic field data similar to those in the chromosphere. In our preprocessing, we add a new term concerning chromospheric longitudinal fields into the optimization function proposed by Wiegelmann et al. We perform a parameter survey of six free parameters to find minimum force- and torque-freeness with the simulated-annealing method. Analyzed data are a photospheric vector magnetogram of AR 10953 observed with the Hinode spectropolarimeter and a chromospheric longitudinal magnetogram observed with SOLIS spectropolarimeter. It is found that some preprocessed fields show the smallest force- and torque-freeness and are very similar to the chromospheric longitudinal fields. On the other hand, other preprocessed fields show noisy maps, although the force- and torque-freeness are of the same order. By analyzing preprocessed noisy maps in the wave number space, we found that small and large wave number components balance out on the force-free index. We also discuss our iteration limit of the simulated-annealing method and magnetic structure broadening in the chromosphere.

  5. Longitudinal analysis of mouse SDOCT volumes

    NASA Astrophysics Data System (ADS)

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

    2017-03-01

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

  6. Partly conditional survival models for longitudinal data.

    PubMed

    Zheng, Yingye; Heagerty, Patrick J

    2005-06-01

    It is common in longitudinal studies to collect information on the time until a key clinical event, such as death, and to measure markers of patient health at multiple follow-up times. One approach to the joint analysis of survival and repeated measures data adopts a time-varying covariate regression model for the event time hazard. Using this standard approach, the instantaneous risk of death at time t is specified as a possibly semi-parametric function of covariate information that has accrued through time t. In this manuscript, we decouple the time scale for modeling the hazard from the time scale for accrual of available longitudinal covariate information. Specifically, we propose a class of models that condition on the covariate information through time s and then specifies the conditional hazard for times t, where t > s. Our approach parallels the "partly conditional" models proposed by Pepe and Couper (1997, Journal of the American Statistical Association 92, 991-998) for pure repeated measures applications. Estimation is based on the use of estimating equations applied to clusters of data formed through the creation of derived survival times that measure the time from measurement of covariates to the end of follow-up. Patient follow-up may be terminated either by the occurrence of the event or by censoring. The proposed methods allow a flexible characterization of the association between a longitudinal covariate process and a survival time, and facilitate the direct prediction of survival probabilities in the time-varying covariate setting.

  7. Longitudinal Electroproduction of Charged Pions from

    SciTech Connect

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

    2001-11-12

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

  8. Longitudinal wakefield for an axisymmetric collimator

    SciTech Connect

    Blednykh A.; Krinsky, S.

    2012-05-25

    We consider the longitudinal point-charge wakefield, w(s), for an axisymmetric collimator having inner radius b, outer radius d, inner length g, and taper length L. The taper angle {alpha} is defined by tan {alpha} = (d-b)/L. Using the electromagnetic simulation code ECHO, we explore the dependence of the wakefield on a collimator's geometric parameters over a wide range of profiles: from small-angle tapers to step-function transitions. The point-charge wakefield is determined using an approximation introduced by Podobedov and Stupakov. We have found it useful to exhibit the wakefield as a function of the scaled variable s/d{alpha}. For small taper angles, our results illustrate the satisfaction of the longitudinal scaling found by Stupakov, Bane, and Zagorodnov; and for larger taper angles, the breaking of this longitudinal scaling is clearly depicted. The use of the scaled variable s/d{alpha} turns out to be especially well suited to describing the wakefield for a collimator with step-function profile ({alpha} = {pi}/2).

  9. Longitudinal analysis of attitudes toward wolves.

    PubMed

    Treves, Adrian; Naughton-Treves, Lisa; Shelley, Victoria

    2013-04-01

    Understanding individual attitudes and how these predict overt opposition to predator conservation or direct, covert action against predators will help to recover and maintain them. Studies of attitudes toward wild animals rely primarily on samples of individuals at a single time point. We examined longitudinal change in individuals' attitudes toward gray wolves (Canis lupus). In the contiguous United States, amidst persistent controversy and opposition, abundances of gray wolves are at their highest in 60 years. We used mailed surveys to sample 1892 residents of Wisconsin in 2001 or 2004 and then resampled 656 of these individuals who resided in wolf range in 2009. Our study spanned a period of policy shifts and increasing wolf abundance. Over time, the 656 respondents increased agreement with statements reflecting fear of wolves, the belief that wolves compete with hunters for deer (Odocoileus virginianus), and inclination to poach a wolf. Endorsement of lethal control of wolves by the state and public hunting of wolves also increased. Neither the time span over which respondents reported exposure to wolves locally nor self-reported losses of domestic animals to wolves correlated with changes in attitude. We predict future increases in legal and illegal killing of wolves that may reduce their abundance in Wisconsin unless interventions are implemented to improve attitudes and behavior toward wolves. To assess whether interventions change attitudes, longitudinal studies like ours are needed. Análisis Longitudinal de las Actitudes Hacia Lobos. © 2013 Society for Conservation Biology.

  10. Material deprivation and health: a longitudinal study.

    PubMed

    Tøge, Anne Grete; Bell, Ruth

    2016-08-08

    Does material deprivation affect the consequences of ill health? Answering this question requires that we move beyond the effects of income. Longitudinal data on material deprivation, longstanding illness and limiting longstanding illness enables investigations of the effects of material deprivation on risk of limiting longstanding illness. This study investigates whether a shift from affording to not affording a car predicts the probability of limiting longstanding ill (LLSI). The 2008-2011 longitudinal panel of Statistics on Income, Social Inclusion and Living Conditions (EU-SILC) is utilised. Longitudinal fixed effects logit models are applied, using LLSI as dependent variable. Transition from affording a car to not affording a car is used as a proxy for material deprivation. All models are controlled for whether the person becomes longstanding ill (LSI) as well as other time-variant covariates that could affect the results. The analysis shows a statistically significant increased odds ratio of LLSI when individuals no longer can afford a car, after controlling for confounders and LSI in the previous year (1.129, CI = 1.022-1.248). However, when restricting the sample to observations where respondents report longstanding illness the results are no longer significant (1.032, CI = 0.910-1.171). The results indicate an individual level effect of material deprivation on LLSI, suggesting that material resources can affect the consequences of ill health.

  11. Quality of reporting of observational longitudinal research.

    PubMed

    Tooth, Leigh; Ware, Robert; Bain, Chris; Purdie, David M; Dobson, Annette

    2005-02-01

    Observational longitudinal research is particularly useful for assessing etiology and prognosis and for providing evidence for clinical decision making. However, there are no structured reporting requirements for studies of this design to assist authors, editors, and readers. The authors developed and tested a checklist of criteria related to threats to the internal and external validity of observational longitudinal studies. The checklist criteria concerned recruitment, data collection, biases, and data analysis and descriptive issues relevant to study rationale, study population, and generalizability. Two raters independently assessed 49 randomly selected articles describing stroke research published from 1999 to 2003 in six journals: American Journal of Epidemiology, Journal of Epidemiology and Community Health, Stroke, Annals of Neurology, Archives of Physical Medicine and Rehabilitation, and American Journal of Physical Medicine and Rehabilitation. On average, 17 of the 33 checklist criteria were reported. Criteria describing the study design were better reported than those related to internal validity. No relation was found between study type (etiologic or prognostic) or word count and quality of reporting. A flow diagram for summarizing participant flow through a study was developed. Editors and authors should consider using a checklist and flow diagram when reporting on observational longitudinal research.

  12. Magnetization Transfer Induced Biexponential Longitudinal Relaxation

    PubMed Central

    Prantner, Andrew M.; Bretthorst, G. Larry; Neil, Jeffrey J.; Garbow, Joel R.; Ackerman, Joseph J.H.

    2009-01-01

    Longitudinal relaxation of brain water 1H magnetization in mammalian brain in vivo is typically analyzed on a per voxel basis using a monoexponential model, thereby assigning a single relaxation time constant to all 1H magnetization within a given voxel. This approach was tested by obtaining inversion recovery data from grey matter of rats at 64 exponentially-spaced recovery times. Using Bayesian probability for model selection, brain water data were best represented by a biexponential function characterized by fast and slow relaxation components. At 4.7 T, the amplitude fraction of the rapidly relaxing component is 3.4 ± 0.7 % with a rate constant of 44 ± 12 s-1 (mean ± SD; 174 voxels from 4 rats). The rate constant of the slow relaxing component is 0.66 ± 0.04 s-1. At 11.7 T, the corresponding values are 6.9 ± 0.9 %, 19 ± 5 s-1, and 0.48 ± 0.02 s-1 (151 voxels from 4 rats). Several putative mechanisms for biexponential relaxation behavior were evaluated, and magnetization transfer between bulk water protons and non-aqueous protons was determined to be the source of biexponential longitudinal relaxation. MR methods requiring accurate quantification of longitudinal relaxation may need to take this effect explicitly into account. PMID:18759367

  13. Nucleon Spin Structure: Longitudinal and Transverse

    SciTech Connect

    Jian-Ping Chen

    2011-02-01

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

  14. Joint multiple imputation for longitudinal outcomes and clinical events that truncate longitudinal follow-up.

    PubMed

    Hu, Bo; Li, Liang; Greene, Tom

    2016-07-30

    Longitudinal cohort studies often collect both repeated measurements of longitudinal outcomes and times to clinical events whose occurrence precludes further longitudinal measurements. Although joint modeling of the clinical events and the longitudinal data can be used to provide valid statistical inference for target estimands in certain contexts, the application of joint models in medical literature is currently rather restricted because of the complexity of the joint models and the intensive computation involved. We propose a multiple imputation approach to jointly impute missing data of both the longitudinal and clinical event outcomes. With complete imputed datasets, analysts are then able to use simple and transparent statistical methods and standard statistical software to perform various analyses without dealing with the complications of missing data and joint modeling. We show that the proposed multiple imputation approach is flexible and easy to implement in practice. Numerical results are also provided to demonstrate its performance. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  15. The Disease Activity Score (DAS) and the Disease Activity Score using 28 joint counts (DAS28) in the management of rheumatoid arthritis.

    PubMed

    van Riel, Piet L C M; Renskers, Lisanne

    2016-01-01

    In rheumatoid arthritis (RA), disease activity cannot be measured in all individual patients according to a single variable. The Disease Activity Score (DAS) and the DAS28 have been developed to measure disease activity in RA both in daily clinical practice as well as in clinical trials on a group as well as individual level. The DAS/DAS28 is a continuous measure of RA disease activity that combines information from swollen joints, tender joints, acute phase response and general health. The DAS-based EULAR response criteria were primarily developed to be used in clinical trials. The EULAR response criteria classify individual patients as non-, moderate, or good responders, dependent on the magnitude of change and level of disease activity reached. In addition, already in the early nineties, cut points were developed to categorise patients in remission. The DAS28 is incorporated in several electronic patient records and web-based systems for monitoring purposes in daily clinical practice. In addition to this, it is being used in combination with patient-reported outcome measures (PROMs) to facilitate self-monitoring.

  16. Detecting Changes Following the Provision of Assistive Devices: Utility of the WHO-DAS II

    ERIC Educational Resources Information Center

    Raggi, Alberto

    2010-01-01

    The World Health Organization Disability Assessment Schedule II (WHO-DAS II) is a non-disease-specific International Classification of Functioning, Disability, and Health-based disability assessment instrument developed to measure activity limitations and restrictions to participation. The aim of this pilot study is to evaluate WHO-DAS II…

  17. Psychometric Properties of the Disability Assessment Schedule (DAS) for Behavior Problems: An Independent Investigation

    ERIC Educational Resources Information Center

    Tsakanikos, Elias; Underwood, Lisa; Sturmey, Peter; Bouras, Nick; McCarthy, Jane

    2011-01-01

    The present study employed the Disability Assessment Schedule (DAS) to assess problem behaviors in a large sample of adults with ID (N = 568) and evaluate the psychometric properties of this instrument. Although the DAS problem behaviors were found to be internally consistent (Cronbach's [alpha] = 0.87), item analysis revealed one weak item…

  18. Detecting Changes Following the Provision of Assistive Devices: Utility of the WHO-DAS II

    ERIC Educational Resources Information Center

    Raggi, Alberto

    2010-01-01

    The World Health Organization Disability Assessment Schedule II (WHO-DAS II) is a non-disease-specific International Classification of Functioning, Disability, and Health-based disability assessment instrument developed to measure activity limitations and restrictions to participation. The aim of this pilot study is to evaluate WHO-DAS II…

  19. Psychometric Properties of the Disability Assessment Schedule (DAS) for Behavior Problems: An Independent Investigation

    ERIC Educational Resources Information Center

    Tsakanikos, Elias; Underwood, Lisa; Sturmey, Peter; Bouras, Nick; McCarthy, Jane

    2011-01-01

    The present study employed the Disability Assessment Schedule (DAS) to assess problem behaviors in a large sample of adults with ID (N = 568) and evaluate the psychometric properties of this instrument. Although the DAS problem behaviors were found to be internally consistent (Cronbach's [alpha] = 0.87), item analysis revealed one weak item…

  20. Estudo em microondas do aprisionamento e precipitação de elétrons em explosões solares

    NASA Astrophysics Data System (ADS)

    Rosal, A. C.; Costa, J. E. R.

    2003-08-01

    Uma explosão solar é uma variação rápida e intensa do brilho que ocorre nas chamadas regiões ativas da atmosfera, constituídas por um plasma magnetizado com intensa indução magnética. Os modelos de explosões solares atuais, discutidos na literatura, apresentam características de aprisionamento e precipitação de elétrons em ambientes magnéticos simplificados. Neste trabalho, nos propusemos a separar a emissão dos elétrons aprisionados da emissão dos elétrons em precipitação apenas a partir da emissão em microondas, melhorando portanto o controle sobre o conjunto de parâmetros inferidos. A emissão em microondas da população em precipitação é bastante fraca e portanto da nossa base de dados de 130 explosões observadas pelo Rádio Polarímetro de Nobeyama, em sete freqüências, apenas para 32 foi possível separar as duas componentes de emissão com uma boa razão sinal/ruído. A partir de estudos das escalas de tempo das emissões devidas à variação gradual da emissão no aprisionamento e da variação rápida da emissão dos elétrons em precipitação foi possível obter a separação utilizando um filtro temporal nas emissões resultantes. Em nossa análise destas explosões estudamos os espectros girossincrotrônicos da emissão gradual, a qual associamos provir do topo dos arcos magnéticos e da emissão de variação rápida associada aos elétrons em precipitação. Estes espectros foram calculados e dos quais inferimos que a indução magnética efetiva do topo e dos pés foi em média, Btopo = 236 G e Bpés = 577 G, inferidas das freqüências de pico dos espectros em ntopo = 11,8 GHz e npés = 14,6 GHz com leve anisotropia (pequeno alargamento espectral). O índice espectral da distribuição não-térmica de elétrons d, inferido do índice espectral de fótons da emissão em regime opticamente fino, foi de dtopo = 3,3 e dpés = 3,9. Estes parâmetros são típicos da maioria das análises realizadas em ambiente único de

  1. Novel and emerging strategies for longitudinal data collection.

    PubMed

    Udtha, Malini; Nomie, Krystle; Yu, Erica; Sanner, Jennifer

    2015-03-01

    To describe novel and emerging strategies practiced globally in research to improve longitudinal data collection. In research studies, numerous strategies such as telephone interviews, postal mailing, online questionnaires, and electronic mail are traditionally utilized in longitudinal data collection. However, due to technological advances, novel and emerging strategies have been applied to longitudinal data collection, such as two-way short message service, smartphone applications (or "apps"), retrieval capabilities applied to the electronic medical record, and an adapted cloud interface. In this review, traditional longitudinal data collection strategies are briefly described, emerging and novel strategies are detailed and explored, and information regarding the impact of novel methods on participant response rates, the timeliness of participant responses, and cost is provided. We further discuss how these novel and emerging strategies affect longitudinal data collection and advance research, specifically nursing research. Evidence suggests that the novel and emerging longitudinal data collection strategies discussed in this review are valuable approaches to consider. These strategies facilitate collecting longitudinal research data to better understand a variety of health-related conditions. Future studies, including nursing research, should consider using novel and emerging strategies to advance longitudinal data collection. A better understanding of novel and emerging longitudinal data collection strategies will ultimately improve longitudinal data collection as well as foster research efforts. Nurse researchers, along with all researchers, must be aware of and consider implementing novel and emerging strategies to ensure future healthcare research success. © 2014 Sigma Theta Tau International.

  2. Das Programm Oder 2006. Hochwasserschutz in Polen im Zuge der EU-Osterweiterung

    NASA Astrophysics Data System (ADS)

    Kühne, Olaf

    Hochwasser ist ein natürliches Ereignis: Seit jeher sind die Menschen mit Hochwasser und seinen Auswirkungen konfrontiert. Das Ausmaß von Hochwasser reicht dabei von Straßenüberschwemmungen bis zur Überflutung ganzer Landesteile. Auch im Oderflußsystem waren und sind Überschwemmungen keine Seltenheit, in den letzten 200 Jahren ereigneten sie sich in den Jahren 1813, 1838, 1854, 1870, 1903, 1958, 1965, 1970, 1972, 1977, 1981, 1985 und 1997. Das Hochwasser von 1997 war jedoch das schwerste im genannten Zeitraum. Als Reaktion auf das Hochwasser von 1997 wurde in der betroffenen Region das Programm 〝Oder 2006`` entwickelt. Mit seiner Hilfe sollen die Auswirkungen künftiger Hochwasserereignisse abgeschwächt werden.

  3. [Methodological problems of longitudinal studies on schizophrenia].

    PubMed

    Häfner, H; an der Heiden, W

    2000-05-01

    Longitudinal studies are a key to understanding schizophrenia. They are the more informative, the longer the periods covered. Hence, good studies into the course of schizophrenia almost exclusively involve a lot of effort and cost. In practice, however, time-consuming methods and design variables must be avoided. The pitfalls this constraint produces are instructive of the difficulties longitudinal studies are faced with in striving for valid results. For reasons of research economy, requirements must be adjusted to study objectives. Studies into the short term course are less time-consuming, but because of the rapid changes in the illness course study intervals should be defined clearly and observed strictly. In long-term studies, too, one source of error lies in the highly varying lengths of illness of the patients studied. Even some of the classic long-term studies are marred by this error. The beginning of the follow-up period should be comparable across the study cohort and as close to illness onset as possible. To obtain generally valid results the probands must be representative of all the illness cases in the general population not only at the outset, but also all the later stages of the study. Besides the efforts to avoid attrition in the study cohort, ways must be found for correcting and estimating data for an acceptable proportion of drop-outs. In the analysis of course and outcome the indicators chosen must be apt to the traditional subtypes as well as to a theoretical symptom patterns and empirical symptom structures. In the context of typical design variables of longitudinal studies the assets and weaknesses of two retrospective and one prospective design will be discussed. Concerning the social course, importance of disease-independent factors, such as age, sex and level of social development at illness onset, as well as of control groups will be demonstrated. Predictor models will be discussed with reference to the direct and indirect influences

  4. [Educational status and patterns of weight gain in adulthood in Brazil: Estudo Pró-Saúde].

    PubMed

    Fonseca, Maria de Jesus Mendes da; França, Rosana de Figueiredo; Faerstein, Eduardo; Werneck, Guilherme Loureiro; Chor, Dóra

    2012-11-01

    The aim of the present study was to investigate the association between participant and parental educational status (considered as an indicator of socioeconomic status) and participant pattern of weight gain in adulthood. We analyzed data from 2 582 baseline participants (1999) of Estudo Pró-Saúde (Pro-Health Study), a longitudinal investigation of civil servants from a public university in Rio de Janeiro, Brazil. Self-administered questionnaires were used to identify patterns of weight gain in adulthood. Odds ratios (OR) and 95% confidence intervals (95%CI) were estimated for the association between parental and participant educational status and steady weight gain or weight cycling, with stable weight as a reference, using multinomial logistic regression models. For males, lower paternal educational level entailed a chance about 55% lower of weight cycling as compared to stable weight (OR = 0.45; IC95% = 0.26-0.78), whereas lower maternal schooling was related to increased risk of weight cycling, although without reaching statistical significance (OR = 1.68; IC95% = 0.94-3.00). The association between participant educational status and weight history was not statistically significant among men. In women, lower educational status entailed a chance 94% higher of self-reported weight cycling (OR = 1.94; 95% CI = 1.17-3.23), and there was no association between parental educational level and history of weight gain. In this study, changes in weight throughout life, both steady and cyclic, were associated with parental and participant educational status, with major differences between genders.

  5. Emotion regulation and childhood aggression: longitudinal associations.

    PubMed

    Röll, Judith; Koglin, Ute; Petermann, Franz

    2012-12-01

    Accumulating evidence suggests that emotion dysregulation is associated with psychopathology. This paper provides a review of recent longitudinal studies that investigate the relationship between emotion regulation and aggressive behavior in childhood age. While there is substantial evidence for assuming a close relation of emotion regulation and aggressive behavior, moderating and mediating factors like gender and peer rejection have been established. Furthermore, results suggest emotion dysregulation as an important risk factor of aggressive behavior. Several directions for future research are pointed out to further validate and refine the reviewed relationships.

  6. Fracture structure near a longitudinal shear macrorupture

    NASA Astrophysics Data System (ADS)

    Goldstein, R. V.; Osipenko, N. M.

    2012-09-01

    Fracture evolution the near a main longitudinal shear in the presence of normal stresses is studied. Experiments with model materials (gypsum, cheese) showed that a multiscale echelon structure of cracks feathering the main rupture is formed under the shear domination conditions. A system of small cracks in the initial echelon is replaced by an echelon of larger and sparser cracks. Intensive transverse compression along the normal to the shear plane, which imitates the initial stress concentrator, takes the fracture region away from the shear plane. A model of evolution development of the observed echelon structure along the main rupture front under the shear domination conditions is proposed.

  7. Linear stability of streamwise developing longitudinal vortices

    NASA Technical Reports Server (NTRS)

    Spall, Robert E.

    1993-01-01

    The linear stability of numerical solutions to the quasicylindrical equations of motion for swirling flows is investigated. Initial conditions are derived from Batchelor's similarity solution for a trailing line vortex. The stability calculations are performed using a 2nd-order accurate finitedifference scheme on a staggered grid with the accuracy of the computed eigenvalues enhanced through Richardson extrapolation. The streamwise development of both viscous and inviscid instability modes is discussed for low and high swirl cases. The effect of adverse and favorable pressure gradients on the viscous stability of a longitudinal vortex is also investigated.

  8. Longitudinal Diagnostics for Short Electron Beam Bunches

    SciTech Connect

    Loos, H.; /SLAC

    2010-06-11

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

  9. Cross-Sectional, Longitudinal and Composite Longitudinal Data on the Career Maturity Inventory Scale.

    ERIC Educational Resources Information Center

    Adelstein, Diane M.; Webster, Dennis W.

    1979-01-01

    Compared the results obtained by two traditional designs on the Career Maturity Inventory-Attitude Scale with the effects of an alternative design: constructing a composite longitudinal gradient. The two traditional methodologies yielded different results from each other for males, but not for females. (Author)

  10. Disease Activity Score 28 (DAS28) using C‐reactive protein underestimates disease activity and overestimates EULAR response criteria compared with DAS28 using erythrocyte sedimentation rate in a large observational cohort of rheumatoid arthritis patients in Japan

    PubMed Central

    Matsui, Toshihiro; Kuga, Yoshiaki; Kaneko, Atsushi; Nishino, Jinju; Eto, Yoshito; Chiba, Noriyuki; Yasuda, Masayuki; Saisho, Koichiro; Shimada, Kota; Tohma, Shigeto

    2007-01-01

    Objectives To compare disease activity and the improvement of disease activity evaluated between by Disease Activity Score 28 using erythrocyte sedimentation rate (DAS28‐ESR) and by DAS28 using C‐reactive protein (DAS28‐CRP) in Japanese patients with rheumatoid arthritis (RA). Methods Data from 3073 RA patients registered in the large cohort database (NinJa: National Database of Rheumatic Diseases by iR‐net in Japan) of 2003 was used to calculate DAS28‐ESR and DAS28‐CRP and disease activities were evaluated. Improvements in disease activities were also evaluated according to the European League Against Rheumatism (EULAR) response criteria in 1482 RA patients whose DAS28‐ESR and DAS28‐CRP could be calculated from data for both 2002 and 2003. Results The mean value of DAS28‐CRP (3.59, SD 1.25) was significantly smaller than that of mean DAS28‐ESR (4.31, SD 1.32) (p < 0.0001). The number of patients who satisfied the criteria of remission was 297 (9.7%) in DAS28‐ESR versus 705 (22.9%) in DAS28‐CRP and the number of patients with high disease activity was 842 (27.4%) versus 357 (11.6%) for DAS28‐ESR and DAS28‐CRP, respectively; there was a significant difference between the two (p < 0.0001). Change of respective DAS28 was significantly correlated (ΔDAS28‐ESR −0.05, SD 1.14 versus ΔDAS28‐CRP −0.10, SD 1.10) (p < 0.0001); however, the number of “good response” patients was significantly different (p < 0.03) between DAS28‐ESR (97 patients, 6.5%) and DAS28‐CRP (136 patients, 9.2%). Conclusions DAS28‐CRP significantly underestimated disease activity and overestimated the improvement in disease activity compared with DAS28‐ESR. DAS28‐CRP should be evaluated using different criteria from that for DAS28‐ESR. PMID:17369281

  11. A Class of Markov Models for Longitudinal Ordinal Data

    PubMed Central

    Lee, Keunbaik; Daniels, Michael J.

    2009-01-01

    Summary Generalized linear models with serial dependence are often used for short longitudinal series. Heagerty (2002, Biometrics 58, 342–351) has proposed marginalized transition models for the analysis of longitudinal binary data. In this article, we extend this work to accommodate longitudinal ordinal data. Fisher-scoring algorithms are developed for estimation. Methods are illustrated on quality-of-life data from a recent colorectal cancer clinical trial. PMID:18078479

  12. Longitudinal Studies of Attitude Change: Issues and Methods

    DTIC Science & Technology

    1975-04-01

    relative contributions of variables which are presently influencing attitudes from historical variables. Conversely a longitudinal method can be used to...different training techniques. Neidt and Meredith (1966) used a longitudinal method to determine the changes in attitudes of a single group of Air... longitudinal method is viewed as the most promising for measurement of change. With the increasing improvement in unobtrusive measures (e.g., Webb

  13. Splinting of Longitudinal Fracture: An Innovative Approach

    PubMed Central

    Bansal, Rashmi; Chowdhary, Priyanka; Gurtu, Anuraag; Mehrotra, Nakul; Kishore, Abhinav

    2016-01-01

    Trauma may result in craze lines on the enamel surface, one or more fractured cusps of posterior teeth, cracked tooth syndrome, splitting of posterior teeth, and vertical fracture of root. Out of these, management of some fractures is of great challenge and such teeth are generally recommended for extraction. Literature search reveals attempts to manage such fractures by full cast crown, orthodontic wires, and so forth, in which consideration was given to extracoronal splinting only. However, due to advancement in materials and technologies, intracoronal splinting can be achieved as well. In this case report, longitudinal fractures in tooth #27, tooth #37, and tooth #46 had occurred. In #27, fracture line was running mesiodistally involving the pulpal floor resulting in a split tooth. In teeth 37 and 46, fractures of the mesiobuccal cusp and mesiolingual cusp were observed, respectively. They were restored with cast gold inlay and full cast crown, respectively. Longitudinal fracture of 27 was treated with an innovative approach using intracanal reinforced composite with Ribbond, external reinforcement with an orthodontic band, and full cast metal crown to splint the split tooth. PMID:27247808

  14. Analyzing incomplete longitudinal clinical trial data.

    PubMed

    Molenberghs, Geert; Thijs, Herbert; Jansen, Ivy; Beunckens, Caroline; Kenward, Michael G; Mallinckrodt, Craig; Carroll, Raymond J

    2004-07-01

    Using standard missing data taxonomy, due to Rubin and co-workers, and simple algebraic derivations, it is argued that some simple but commonly used methods to handle incomplete longitudinal clinical trial data, such as complete case analyses and methods based on last observation carried forward, require restrictive assumptions and stand on a weaker theoretical foundation than likelihood-based methods developed under the missing at random (MAR) framework. Given the availability of flexible software for analyzing longitudinal sequences of unequal length, implementation of likelihood-based MAR analyses is not limited by computational considerations. While such analyses are valid under the comparatively weak assumption of MAR, the possibility of data missing not at random (MNAR) is difficult to rule out. It is argued, however, that MNAR analyses are, themselves, surrounded with problems and therefore, rather than ignoring MNAR analyses altogether or blindly shifting to them, their optimal place is within sensitivity analysis. The concepts developed here are illustrated using data from three clinical trials, where it is shown that the analysis method may have an impact on the conclusions of the study.

  15. Analysis strategies for longitudinal attachment loss data.

    PubMed

    Beck, J D; Elter, J R

    2000-02-01

    The purpose of this invited review is to describe and discuss methods currently in use to quantify the progression of attachment loss in epidemiological studies of periodontal disease, and to make recommendations for specific analytic methods based upon the particular design of the study and structure of the data. The review concentrates on the definition of incident attachment loss (ALOSS) and its component parts; measurement issues including thresholds and regression to the mean; methods of accounting for longitudinal change, including changes in means, changes in proportions of affected sites, incidence density, the effect of tooth loss and reversals, and repeated events; statistical models of longitudinal change, including the incorporation of the time element, use of linear, logistic or Poisson regression or survival analysis, and statistical tests; site vs person level of analysis, including statistical adjustment for correlated data; the strengths and limitations of ALOSS data. Examples from the Piedmont 65+ Dental Study are used to illustrate specific concepts. We conclude that incidence density is the preferred methodology to use for periodontal studies with more than one period of follow-up and that the use of studies not employing methods for dealing with complex samples, correlated data, and repeated measures does not take advantage of our current understanding of the site- and person-level variables important in periodontal disease and may generate biased results.

  16. Longitudinal Predictors of Institutionalization in Old Age

    PubMed Central

    Hajek, André; Brettschneider, Christian; Lange, Carolin; Posselt, Tina; Wiese, Birgitt; Steinmann, Susanne; Weyerer, Siegfried; Werle, Jochen; Pentzek, Michael; Fuchs, Angela; Stein, Janine; Luck, Tobias; Bickel, Horst; Mösch, Edelgard; Wagner, Michael; Jessen, Frank; Maier, Wolfgang; Scherer, Martin

    2015-01-01

    Objective To investigate time-dependent predictors of institutionalization in old age using a longitudinal approach. Methods In a representative survey of the German general population aged 75 years and older predictors of institutionalization were observed every 1.5 years over six waves. Conditional fixed-effects logistic regressions (with 201 individuals and 960 observations) were performed to estimate the effects of marital status, depression, dementia, and physical impairments (mobility, hearing and visual impairments) on the risk of admission to old-age home or nursing home. By exploiting the longitudinal data structure using panel econometric models, we were able to control for unobserved heterogeneity such as genetic predisposition and personality traits. Results The probability of institutionalization increased significantly with occurrence of widowhood, depression, dementia, as well as walking and hearing impairments. In particular, the occurrence of widowhood (OR = 78.3), dementia (OR = 154.1) and substantial mobility impairment (OR = 36.7) were strongly associated with institutionalization. Conclusion Findings underline the strong influence of loss of spouse as well as dementia on institutionalization. This is relevant as the number of old people (a) living alone and (b) suffering from dementia is expected to increase rapidly in the next decades. Consequently, it is supposed that the demand for institutionalization among the elderly will increase considerably. Practitioners as well as policy makers should be aware of these upcoming challenges. PMID:26658776

  17. Preceptor teaching tips in longitudinal clerkships.

    PubMed

    Latessa, Robyn; Schmitt, Anthony; Beaty, Norma; Buie, Stephen; Ray, Lisa

    2016-06-01

    In longitudinal integrated clerkships (LICs), the continuous preceptor and student relationship over time creates opportunities for more in-depth teaching approaches than shorter preceptorships allow. We identify student perceptions of the most effective teaching practices and develop tips for LIC preceptors. The first four third-year medical student classes completing the Asheville LIC of the University of North Carolina School of Medicine (UNC SOM) formed the subject group. Between June and August 2013, a trained research assistant (AS) conducted semi-structured interviews with all 27 UNC SOM Asheville LIC students. Interviews were transcribed and coded by thematic analysis. All 27 (100%) students participated in the interviews. We identified seven main themes of successful precepting practices: enhance teaching; create bring-backs (learning topics to bring back to preceptors); support patient ownership; structure clinic; improve feedback; engage learners; and develop a relationship. These themes were condensed into nine preceptor tips for teaching in LICs. The longitudinal relationship of preceptor and student in LIC models affords specific, important opportunities for teaching and learning. The concise list of LIC preceptor tips can be used by preceptors to further optimise their teaching in the LIC setting. We identify student perceptions of the most effective teaching practices and develop tips for LIC preceptors. © 2015 John Wiley & Sons Ltd.

  18. Anonymization of Longitudinal Electronic Medical Records

    PubMed Central

    Tamersoy, Acar; Loukides, Grigorios; Nergiz, Mehmet Ercan; Saygin, Yucel; Malin, Bradley

    2013-01-01

    Electronic medical record (EMR) systems have enabled healthcare providers to collect detailed patient information from the primary care domain. At the same time, longitudinal data from EMRs are increasingly combined with biorepositories to generate personalized clinical decision support protocols. Emerging policies encourage investigators to disseminate such data in a deidentified form for reuse and collaboration, but organizations are hesitant to do so because they fear such actions will jeopardize patient privacy. In particular, there are concerns that residual demographic and clinical features could be exploited for reidentification purposes. Various approaches have been developed to anonymize clinical data, but they neglect temporal information and are, thus, insufficient for emerging biomedical research paradigms. This paper proposes a novel approach to share patient-specific longitudinal data that offers robust privacy guarantees, while preserving data utility for many biomedical investigations. Our approach aggregates temporal and diagnostic information using heuristics inspired from sequence alignment and clustering methods. We demonstrate that the proposed approach can generate anonymized data that permit effective biomedical analysis using several patient cohorts derived from the EMR system of the Vanderbilt University Medical Center. PMID:22287248

  19. A longitudinal study of urea cycle disorders.

    PubMed

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

    2014-01-01

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

  20. Optimization of longitudinal corrections of helical gears

    NASA Astrophysics Data System (ADS)

    He, Dawei; Fang, Zongde

    1992-07-01

    FEM and mathematical programming are used to obtain optimal longitudinal corrections of helical gears. Consideration is given to: the simultaneous engagement of three pairs of teeth; the influence of deformation of rims and webs; and the influence of deformation of shafts and bearings. A gear surface complex flexibility matrix is established in order to reduce the computer time needed. In the optimization of longitudinal corrections, a large number of iteration computations must be performed. Many meshing positions and contact lines must be considered. There are a great number of points on which forces may act. Flexibilities of points on which forces act are needed in iteration computations. In the past, flexibilities of contact points are computed when needed; as a result, the computer time required is unnecessarily great. Flexibilities of all points on which forces may act and store gear surface complex flexibility matrix in a database are computed. The flexibilities are recalled from data base whenever needed; as a result, the computer time needed is greatly reduced. Aircraft gears in actual use are taken as examples. Calculated results show that optimization or very good load equalization can be attained in theory.

  1. MULTILINEAR TENSOR REGRESSION FOR LONGITUDINAL RELATIONAL DATA.

    PubMed

    Hoff, Peter D

    2015-09-01

    A fundamental aspect of relational data, such as from a social network, is the possibility of dependence among the relations. In particular, the relations between members of one pair of nodes may have an effect on the relations between members of another pair. This article develops a type of regression model to estimate such effects in the context of longitudinal and multivariate relational data, or other data that can be represented in the form of a tensor. The model is based on a general multilinear tensor regression model, a special case of which is a tensor autoregression model in which the tensor of relations at one time point are parsimoniously regressed on relations from previous time points. This is done via a separable, or Kronecker-structured, regression parameter along with a separable covariance model. In the context of an analysis of longitudinal multivariate relational data, it is shown how the multilinear tensor regression model can represent patterns that often appear in relational and network data, such as reciprocity and transitivity.

  2. Colorado longitudinal twin study of reading disability.

    PubMed

    Wadsworth, Sally J; DeFries, John C; Olson, Richard K; Willcutt, Erik G

    2007-12-01

    The primary objectives of the present study are to introduce the Colorado Longitudinal Twin Study of Reading Disability, the first longitudinal twin study in which subjects have been specifically selected for having a history of reading difficulties, and to present some initial assessments of the stability of reading performance and cognitive abilities in this sample. Preliminary examination of the test scores of 124 twins with a history of reading difficulties and 154 twins with no history of reading difficulties indicates that over the 5- to 6-year interval between assessments, cognitive and reading performance are highly stable. As a group, those subjects with a history of reading difficulties had substantial deficits relative to control subjects on all measures at initial assessment, and significant deficits remained at follow-up. The stability noted for all cognitive and achievement measures was highest for a composite measure of reading, whose average stability correlation across groups was 0.80. Results of preliminary behavior genetic analyses for this measure indicated that shared genetic influences accounted for 86% and 49% of the phenotypic correlations between the two assessments for twin pairs with and without reading difficulties, respectively. In addition, genetic correlations reached unity for both groups, suggesting that the same genetic influences are manifested at both time points.

  3. Splinting of Longitudinal Fracture: An Innovative Approach.

    PubMed

    Bansal, Rashmi; Chowdhary, Priyanka; Gurtu, Anuraag; Mehrotra, Nakul; Kishore, Abhinav

    2016-01-01

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

  4. Parental mediation and cyberbullying - a longitudinal study.

    PubMed

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

    2014-01-01

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

  5. Initial Cognitive Performance Predicts Longitudinal Aviator Performance

    PubMed Central

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

    2011-01-01

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

  6. Longitudinal Predictors of Institutionalization in Old Age.

    PubMed

    Hajek, André; Brettschneider, Christian; Lange, Carolin; Posselt, Tina; Wiese, Birgitt; Steinmann, Susanne; Weyerer, Siegfried; Werle, Jochen; Pentzek, Michael; Fuchs, Angela; Stein, Janine; Luck, Tobias; Bickel, Horst; Mösch, Edelgard; Wagner, Michael; Jessen, Frank; Maier, Wolfgang; Scherer, Martin; Riedel-Heller, Steffi G; König, Hans-Helmut

    2015-01-01

    To investigate time-dependent predictors of institutionalization in old age using a longitudinal approach. In a representative survey of the German general population aged 75 years and older predictors of institutionalization were observed every 1.5 years over six waves. Conditional fixed-effects logistic regressions (with 201 individuals and 960 observations) were performed to estimate the effects of marital status, depression, dementia, and physical impairments (mobility, hearing and visual impairments) on the risk of admission to old-age home or nursing home. By exploiting the longitudinal data structure using panel econometric models, we were able to control for unobserved heterogeneity such as genetic predisposition and personality traits. The probability of institutionalization increased significantly with occurrence of widowhood, depression, dementia, as well as walking and hearing impairments. In particular, the occurrence of widowhood (OR = 78.3), dementia (OR = 154.1) and substantial mobility impairment (OR = 36.7) were strongly associated with institutionalization. Findings underline the strong influence of loss of spouse as well as dementia on institutionalization. This is relevant as the number of old people (a) living alone and (b) suffering from dementia is expected to increase rapidly in the next decades. Consequently, it is supposed that the demand for institutionalization among the elderly will increase considerably. Practitioners as well as policy makers should be aware of these upcoming challenges.

  7. A longitudinal study of urea cycle disorders

    PubMed Central

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

    2014-01-01

    The urea cycle disorders consortium (UCDC) is a member of the NIH funded Rare Diseases Clinical Research Network and is performing a longitudinal study of 8 urea cycle disorders (UCD) with initial enrollment beginning in 2006. The consortium consists of 14 sites in the U.S., Canada and Europe. This report summarizes data mining studies of 614 patients with UCD enrolled in the UCDC’s longitudinal study protocol. The most common disorder is ornithine transcarbamylase deficiency, accounting for more than half of the participants. We calculated the overall prevalence of urea cycle disorders to be 1/35,000, with 2/3rds presenting initial symptoms after the newborn period. We found the mortality rate to be 24% in neonatal onset cases and 11% in late onset cases. The most common precipitant of clinical hyperammonemic episodes in the post-neonatal period was intercurrent infections. Elevations in both blood ammonia and glutamine appeared to be biomarkers for neurocognitive outcome. In terms of chronic treatment, low protein diet appeared to result in normal weight but decreased linear growth while N-scavenger therapy with phenybutyrate resulted in low levels of branched chain amino acids. Finally, we found an unexpectedly high risk for hepatic dysfunction in patients with ornithine transcarbamylase deficiency. This natural history study illustrates how a collaborative study of a rare genetic disorder can result in an improved understanding of morbidity and disease outcome. PMID:25135652

  8. Multivariate Longitudinal Analysis with Bivariate Correlation Test

    PubMed Central

    Adjakossa, Eric Houngla; Sadissou, Ibrahim; Hounkonnou, Mahouton Norbert; Nuel, Gregory

    2016-01-01

    In the context of multivariate multilevel data analysis, this paper focuses on the multivariate linear mixed-effects model, including all the correlations between the random effects when the dimensional residual terms are assumed uncorrelated. Using the EM algorithm, we suggest more general expressions of the model’s parameters estimators. These estimators can be used in the framework of the multivariate longitudinal data analysis as well as in the more general context of the analysis of multivariate multilevel data. By using a likelihood ratio test, we test the significance of the correlations between the random effects of two dependent variables of the model, in order to investigate whether or not it is useful to model these dependent variables jointly. Simulation studies are done to assess both the parameter recovery performance of the EM estimators and the power of the test. Using two empirical data sets which are of longitudinal multivariate type and multivariate multilevel type, respectively, the usefulness of the test is illustrated. PMID:27537692

  9. Longitudinal Section AA; Lower Chord Plan Powerscourt Bridge, Spanning ...

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

    Longitudinal Section A-A; Lower Chord Plan - Powerscourt Bridge, Spanning Chateauguay River, First Concession Road, Elgin/Hichinbrooke, Huntingdon County, Quebec, Canada, Chateaugay, Franklin County, NY

  10. Coupling and degenerating modes in longitudinal-torsional step horns.

    PubMed

    Harkness, Patrick; Lucas, Margaret; Cardoni, Andrea

    2012-12-01

    Longitudinal-torsional vibration is used and proposed for a variety of ultrasonic applications including motors, welding, and rock-cutting. To obtain this behavior in an ultrasonic step horn one can either, (i) couple the longitudinal and torsional modes of the horn by incorporating a ring of diagonal slits in the thick base section or, (ii) place helical flutes in the thin stem section to degenerate the longitudinal mode into a modified behavior with a longitudinal-torsional motion. This paper compares the efficacy of these two design approaches using both numerical and experimental techniques. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. Molecular mechanisms in the formation of the medial longitudinal fascicle

    PubMed Central

    Ahsan, Mansoor; Riley, Kerry-lyn; Schubert, Frank R

    2007-01-01

    The first neurons in the vertebrate brain form a stereotypical array of longitudinal and transversal axon tracts, the early axon scaffold. This scaffold is thought to lay down the basic structure for the later, more complex neuronal pathways in the brain. The ventral longitudinal tract is pioneered by neurons located at the ventral midbrain–forebrain boundary, which form the medial longitudinal fascicle. Recent studies have shed some light on the molecular mechanisms that control the development of the medial longitudinal fascicle. Here, we show that patterning molecules, notably the ventralizing signalling molecule Shh, are involved in the formation of medial longitudinal fascicle neurons and in medial longitudinal fascicle axon guidance. Downstream of Shh, several homeobox genes are expressed in the tegmentum. We describe the expression patterns of Sax1, Emx2, Six3, Nkx2.2 and Pax6 in the mesencephalon and pretectum in detail. Furthermore, we review the evidence of their molecular interactions, and their involvement in neuronal fate specification. In particular, Sax1 plays a major role in fate determination of medial longitudinal fascicle neurons. Finally, we discuss the available data on axon guidance mechanisms for the medial longitudinal fascicle, which suggest that different guidance molecules such as class 3 Semaphorins, Slits and Netrins act to determine the caudal and ventral course of the medial longitudinal fascicle axons. PMID:17623036

  12. How to specify and measure sensitivity in Distributed Acoustic Sensing (DAS)?

    NASA Astrophysics Data System (ADS)

    Gabai, Haniel; Eyal, Avishay

    2017-04-01

    In Rayleigh-scattering-based Distributed Acoustic Sensing (DAS) an optical fiber is transformed into an array of thousands of 'virtual microphones'. This approach has gained tremendous popularity in recent years and is one of the most successful examples of a fiber-optic sensing method which made its way from the academia to the market. Despite the great amount of work done in this field, sensitivity, which is ones of the most critical parameters of any sensing technique, was rarely investigated in this context. In particular, little attention was given to its random characteristics. Without careful consideration of the random aspects of DAS, any attempt to specify its sensitivity or to compare between different DAS modalities is of limited value. Recently we introduced a new statistical parameter which defines DAS sensitivity and enables comparison between the performances of different DAS systems. In this paper we generalize the previous parameter and give a broader, simple and intuitive definition to DAS sensitivity. An important attribute of these parameters is that they can be easily extracted from the static backscatter profile of the sensing fiber. In the paper we derive the relation between DAS sensitivity and the static backscatter profile and present an experimental verification of this relation.

  13. DasR positively controls monensin production at two-level regulation in Streptomyces cinnamonensis.

    PubMed

    Zhang, Yue; Lin, Chun-Yan; Li, Xiao-Mei; Tang, Zheng-Kun; Qiao, Jianjun; Zhao, Guang-Rong

    2016-12-01

    The polyether ionophore antibiotic monensin is produced by Streptomyces cinnamonensis and is used as a coccidiostat for chickens and growth-promoting agent for cattle. Monensin biosynthetic gene cluster has been cloned and partially characterized. The GntR-family transcription factor DasR regulates antibiotic production and morphological development in Streptomyces coelicolor and Saccharopolyspora erythraea. In this study, we identified and characterized the two-level regulatory cascade of DasR to monensin production in S. cinnamonensis. Forward and reverse genetics by overexpression and antisense RNA silence of dasR revealed that DasR positively controls monensin production under nutrient-rich condition. Electrophoresis mobility shift assay (EMSA) showed that DasR protein specifically binds to the promoter regions of both pathway-specific regulatory gene monRII and biosynthetic genes monAIX, monE and monT. Semi-quantitative RT-PCR further confirmed that DasR upregulates the transcriptional levels of these genes during monensin fermentation. Subsequently, co-overexpressed dasR with pathway-specific regulatory genes monRI, monRII or monH greatly improved monensin production.

  14. Crosslinking effect of dialdehyde starch (DAS) on decellularized porcine aortas for tissue engineering.

    PubMed

    Wang, Xu; Gu, Zhipeng; Qin, Huanhuan; Li, Li; Yang, Xu; Yu, Xixun

    2015-08-01

    Biological tissue-derived biomaterials must be chemically modified to avoid immediate degradation and immune response before being implanted in human body to replace malfunctioning organs. DAS with active aldehyde groups was employed to replace glutaraldehyde (GA), a most common synthetic crosslinking reagent in clinical practice, to fix bioprostheses for lower cytotoxicity. The aim of this research was to evaluate fixation effect of DAS. The tensile strength, crosslinking stability, cytotoxicity especially the anti-calcification capability of DAS-fixed tissues were investigated. The tensile strength and resistance to enzymatic degradation of samples were increased after DAS fixation, the values maintained stably in D-Hanks solution for several days. Meanwhile, ultrastructure of samples preserved well and the anti-calcification capability of samples were improved, the amount of positive staining points in the whole visual field of 15% DAS-fixed samples was only 0.576 times to GA-fixed ones. Moreover, both unreacted DAS and its hydrolytic products were nontoxic in cytotoxicity study. The results demonstrated DAS might be an effective crosslinking reagent to fix biological tissue-derived biomaterials in tissue engineering. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Longitudinal Muscle Dysfunction in Achalasia Esophagus and Its Relevance

    PubMed Central

    Hong, Su Jin; Bhargava, Valmik

    2013-01-01

    Muscularis propria of the esophagus is organized into circular and longitudinal muscle layers. Goal of this review is to summarize the role of longitudinal muscle in physiology and pathophysiology of esophageal sensory and motor function. Simultaneous manometry and ultrasound imaging that measure circular and longitudinal muscle contraction respectively reveal that during peristalsis 2 layers of the esophagus contract in perfect synchrony. On the other hand, during transient relaxation of the lower esophageal sphincter (LES), longitudinal muscle contracts independently of circular muscle. Recent studies provide novel insights, i.e., longitudinal muscle contraction of the esophagus induces LES relaxation and possibly descending relaxation of the esophagus. In achalasia esophagus and other motility disorders there is discoordination between the 2 muscle layers. Longitudinal muscle contraction patterns are different in the recently described three types of achalasia identified by high-resolution manometry. Robust contraction of the longitudinal muscle in type II achalasia causes pan-esophageal pressurization and is the mechanism of whatever little esophageal emptying that take place in the absence of peristalsis and impaired LES relaxation. It may be that preserved longitudinal muscle contraction is also the reason for superior outcome to medical/surgical therapy in type II achalasia esophagus. Prolonged contractions of longitudinal muscles of the esophagus is a possible mechanism of heartburn and "angina like" pain seen in esophageal motility disorders and possibly achalasia esophagus. Novel techniques to record longitudinal muscle contraction are on the horizon. Neuro-pharmacologic control of circular and longitudinal muscles is different, which provides an important opportunity for the development of novel pharmacological therapies to treat sensory and motor disorders of the esophagus. PMID:23667744

  16. Longitudinal Stability of Common TMJ Structural Disorders.

    PubMed

    Schiffman, E L; Ahmad, M; Hollender, L; Kartha, K; Ohrbach, R; Truelove, E L; Zhang, L; Hodges, J S; Sommers, E; Anderson, G C; Gonzalez, Y M; Guo, X; Look, J O

    2017-03-01

    The longitudinal course of temporomandibular joint (TMJ) disc displacement (DD) and degenerative joint disease (DJD) has never been conclusively described with magnetic resonance imaging and computed tomography, respectively. This 8-y observational study's objective was to assess the longitudinal stability of DD and DJD among 401 subjects. The Validation Project provided baseline measures; follow-up was performed in the TMJ Impact Project. With magnetic resonance imaging, 2 radiologists rendered a consensus diagnosis of normal/indeterminate, DD with reduction, or DD without reduction. Computed tomography consensus diagnoses included normal/indeterminate, grade 1 DJD, or grade 2 DJD. Radiologist reliability was assessed by kappa; a Hui-Walter model was used to estimate, after accounting for diagnostic disagreement, the frequency of diagnostic progression and reversal. Permutation tests were used to test the statistical influence of concurrent baseline diagnoses on diagnostic changes at follow-up. Of 789 baseline joint-specific soft tissue diagnoses of DD, 598 (76%) joints showed no change; 109 (14%) demonstrated progression; and 82 (10%) had reversal. Of 794 joints with baseline joint-specific hard tissue diagnoses of DJD, progression was observed in 122 (15%) joints, no change in 564 (71%), and reversal in 108 (14%). Radiologist reliability (kappa) was 0.73 (95% CI, 0.64 to 0.83) for DD and 0.76 (95% CI, 0.68 to 0.83) for DJD. After accounting for the influence of diagnostic disagreement, progression of hard tissue diagnoses in the right TMJ occurred in 15.2% of subjects (95% CI, 10.5% to 20.8%) and reversal in 8.3% (95% CI, 4.9% to 12.3%); results were similar for soft tissue diagnoses and the left TMJ. Concurrent baseline soft tissue diagnoses were associated with hard tissue diagnostic changes at follow-up ( P < 0.0001). Baseline hard tissue diagnoses showed no statistical association with soft tissue changes at follow-up ( P = 0.11). Longitudinally, 76% of

  17. Analysis of aircraft longitudinal handling qualities

    NASA Technical Reports Server (NTRS)

    Hess, R. A.

    1981-01-01

    The optimal control model (OCM) of the human pilot is applied to the study of aircraft handling qualities. Attention is focused primarily on longitudinal tasks. The modeling technique differs from previous applications of the OCM in that considerable effort is expended in simplifying the pilot/vehicle analysis. After briefly reviewing the OCM, a technique for modeling the pilot controlling higher order systems is introduced. Following this, a simple criterion for determining the susceptibility of an aircraft to pilot induced oscillations (PIO) is formulated. Finally, a model-based metric for pilot rating prediction is discussed. The resulting modeling procedure provides a relatively simple, yet unified approach to the study of a variety of handling qualities problems.

  18. A Longitudinal View of HTTP Traffic

    NASA Astrophysics Data System (ADS)

    Callahan, Tom; Allman, Mark; Paxson, Vern

    In this paper we analyze three and a half years of HTTP traffic observed at a small research institute to characterize the evolution of various facets of web operation. While our dataset is modest in terms of user population, it is unique in its temporal breadth. We leverage the longitudinal data to study various characteristics of the traffic, from client and server behavior to object and connection characteristics. In addition, we assess how the delivery of content is structured across our datasets, including the use of browser caches, the efficacy of network-based proxy caches, and the use of content delivery networks. While each of the aspects we study has been investigated to some extent in prior work, our contribution is a unique long-term characterization.

  19. Parameter identification and modeling of longitudinal aerodynamics

    NASA Technical Reports Server (NTRS)

    Aksteter, J. W.; Parks, E. K.; Bach, R. E., Jr.

    1995-01-01

    Using a comprehensive flight test database and a parameter identification software program produced at NASA Ames Research Center, a math model of the longitudinal aerodynamics of the Harrier aircraft was formulated. The identification program employed the equation error method using multiple linear regression to estimate the nonlinear parameters. The formulated math model structure adhered closely to aerodynamic and stability/control theory, particularly with regard to compressibility and dynamic manoeuvring. Validation was accomplished by using a three degree-of-freedom nonlinear flight simulator with pilot inputs from flight test data. The simulation models agreed quite well with the measured states. It is important to note that the flight test data used for the validation of the model was not used in the model identification.

  20. Multivariate Longitudinal Modeling of Cognitive Aging

    PubMed Central

    Robitaille, Annie; Muniz, Graciela; Piccinin, Andrea M.; Johansson, Boo; Hofer, Scott M.

    2013-01-01

    We illustrate the use of the parallel latent growth curve model using data from OCTO-Twin. We found a significant intercept-intercept and slope-slope association between processing speed and visuospatial ability. Within-person correlations among the occasion-specific residuals were significant, suggesting that the occasion-specific fluctuations around individual’s trajectories, after controlling for intraindividual change, are related between both outcomes. Random and fixed effects for visuospatial ability are reduced when we include structural parameters (directional growth curve model) providing information about changes in visuospatial abilities after controlling for processing speed. We recommend this model to researchers interested in the analysis of multivariate longitudinal change, as it permits decomposition and directly interpretable estimates of association among initial levels, rates of change, and occasion-specific variation. PMID:23589712

  1. Simulation of longitudinal coupled-bunch instabilities

    SciTech Connect

    Thompson, K.A.

    1991-02-07

    The purpose of this note is to document some work done as part of the effort directed at designing and simulating a bunch-by-bunch feedback system to control longitudinal coupled bunch instabilities in the B-factory. In particular, I discuss the ring model used in the simulation program developed to study this feedback system. Basically the simulation is a simple tracking program in which the rf drive voltage, the wakefields due to all the bunches, the synchrotron radiation losses, and the kicks applied to the bunches by the bunch-by-bunch feedback are all modelled as voltages applied at a single, discrete point in the ring. The computation of the bunch-by-bunch feedback voltages may of course be done by any desired algorithms. An example and discussion of the general behavior without bunch-by-bunch feedback is given at the end of this report.

  2. Longitudinal ultrasonic waves in DC electric field

    NASA Astrophysics Data System (ADS)

    Sobotka, Jerzy

    2009-06-01

    The results of experimental studies of the propagation of longitudinal waves in saturated rock samples in which there is a flow of electric charges are presented. It is shown that the electric field affects elastic parameters in heterophase media by changing their dynamic characteristics. The aim of the study of the effect of electric field on the propagation of elastic waves in saturated porous media was to determine the optimum conditions for this effect, and to construct a set of effective parameters which could be used to increase the effectiveness of seismoacoustic prospecting methods, particularly acoustic logging, and be helpful for developing new methods of increasing the effectiveness of oil extraction from productive wells.

  3. The longitudinal development of clusters in French.

    PubMed

    Demuth, Katherine; McCullough, Elizabeth

    2009-03-01

    Studies of English and German find that children tend to acquire word-final consonant clusters before word-initial consonant clusters. This order of acquisition is generally attributed to articulatory, frequency and/or morphological factors. This contrasts with recent experimental findings from French, where two-year-olds were better at producing word-initial than word-final clusters (Demuth & Kehoe, 2006). The purpose of the present study was to examine French-speaking children's longitudinal acquisition of clusters to determine if these results replicate developmentally. Analysis of spontaneous speech productions from two French-speaking children between one and three years confirmed the earlier acquisition of initial clusters, even when sonority factors were controlled. The findings suggest that French-speaking children acquire complexity at the beginnings of words before complexity appears word-finally. The role of frequency, morphological, structural and input factors is discussed.

  4. Beam Tomography in Longitudinal Phase Space

    NASA Astrophysics Data System (ADS)

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

    1997-05-01

    Longitudinal particle motion in circular accelerators is typically monitored by one dimensional (1-D) profiles. Adiabatic particle motion in 2-D phase space can be reconstructed with tomographic techniques, using 1-D profiles. In this paper, we discuss a filtered backprojection algorithm, with a high pass ramp or Hann filter, for phase space reconstruction. The algorithm uses several projections of the beam at equally spaced angles over half a synchrotron period. A computer program RADON has been developed to process digitized mountain range data and do the phase space reconstruction for the AGS, and later for Relativistic Heavy Ion Collider (RHIC). Analysis has been performed to determine the sensitivity to machine parameters and data acquisition errors. During the Sextant test of RHIC in early 1997, this program has been successfully employed to reconstruct the motion of Au^77+ beam in the AGS.

  5. Random-effects models for longitudinal data

    SciTech Connect

    Laird, N.M.; Ware, J.H.

    1982-12-01

    Models for the analysis of longitudinal data must recognize the relationship between serial observations on the same unit. Multivariate models with general covariance structure are often difficult to apply to highly unbalanced data, whereas two-stage random-effects models can be used easily. In two-stage models, the probability distributions for the response vectors of different individuals belong to a single family, but some random-effects parameters vary across individuals, with a distribution specified at the second stage. A general family of models is discussed, which includes both growth models and repeated-measures models as special cases. A unified approach to fitting these models, based on a combination of empirical Bayes and maximum likelihood estimation of model parameters and using the EM algorithm, is discussed. Two examples are taken from a current epidemiological study of the health effects of air pollution.

  6. Longitudinal predictors of high school completion.

    PubMed

    Barry, Melissa; Reschly, Amy L

    2012-06-01

    This longitudinal study examined predictors of dropout assessed in elementary school. Student demographic data, achievement, attendance, and ratings of behavior from the Behavior Assessment System for Children were used to predict dropout and completion. Two models, which varied on student sex and race, predicted dropout at rates ranging from 75% to 88%. Model A, which included the Behavioral Symptoms Index, School Problems composite, Iowa Tests of Basic Skills battery, and teacher ratings of student work habits, best predicted female and African American dropouts. Model B, which comprised the Adaptive Skills composite, the Externalizing composite, the School Problems composite, referral for a student support team meeting, and sex, was more accurate for predicting Caucasian dropouts. Both models demonstrated the same hit rates for predicting male dropouts. Recommendations for early warning indicators and linking predictors with interventions are discussed. (PsycINFO Database Record (c) 2012 APA, all rights reserved).

  7. Longitudinal research on temperament in twins.

    PubMed

    Torgersen, A M

    1987-01-01

    The changing influence of genetic factors of temperamental individuality has been studied longitudinally in a group of 44 same-sexed twin pairs at four different ages from infancy to puberty. Previous results showed that genetic factors seemed to play an important role in the development of temperamental characteristics when the twins were in infancy and at six years of age. The present report shows that when the within-pair differences in temperament are studied again at age 15 years, the similarity of identical pairs is even higher than at earlier ages. When shared and nonshared stress in the twin pairs was assessed at this age, some interactions were found between within-pair differences in temperament, stress and zygosity.

  8. A Longitudinal Study of Adolescent Adjustment Following Family Transitions

    ERIC Educational Resources Information Center

    Ruschena, Eda; Prior, Margot; Sanson, Ann; Smart, Diana

    2005-01-01

    Background: This study examined the impact of family transitions, that is, parental separation, divorce, remarriage and death, upon the lives of Australian children and adolescents in a longitudinal study of temperament and development. Methods: Using longitudinal and concurrent questionnaire data, outcomes for young people experiencing…

  9. Longitudinal and transverse mode evolution in free electron laser

    SciTech Connect

    Dattoli, G.; Giannessi, L.; Georgii, R.

    1995-12-31

    We use the method of Padg approximants and Fourier transform techniques to treat analytically the problem of transverse and longitudinal mode evolution in FELs. We obtain simple relations providing a transparent understanding of the dynamic of pulse propagation effects and of transverse mode guiding. We discuss the interplay with inhomogeneous broadening effects and derive gain formulae including longitudinal and transverse mode couplings.

  10. 14 CFR 23.173 - Static longitudinal stability.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Static longitudinal stability. 23.173 Section 23.173 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Stability § 23.173 Static longitudinal stability. Under the conditions specified in § 23.175 and with...

  11. 14 CFR 23.173 - Static longitudinal stability.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Static longitudinal stability. 23.173 Section 23.173 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Stability § 23.173 Static longitudinal stability. Under the conditions specified in § 23.175 and with...

  12. 14 CFR 23.173 - Static longitudinal stability.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Static longitudinal stability. 23.173 Section 23.173 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Stability § 23.173 Static longitudinal stability. Under the conditions specified in § 23.175 and with...

  13. 14 CFR 23.173 - Static longitudinal stability.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Static longitudinal stability. 23.173 Section 23.173 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Stability § 23.173 Static longitudinal stability. Under the conditions specified in § 23.175 and with...

  14. 14 CFR 23.173 - Static longitudinal stability.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Static longitudinal stability. 23.173 Section 23.173 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Stability § 23.173 Static longitudinal stability. Under the conditions specified in § 23.175 and with...

  15. Early Predictors of Adolescent Depression: A 7-Year Longitudinal Study

    ERIC Educational Resources Information Center

    Mazza, James J.; Abbott, Robert D.; Fleming, Charles B.; Harachi, Tracy W.; Cortes, Rebecca C.; Park, Jisuk; Haggerty, Kevin P.; Catalano, Richard F.

    2009-01-01

    This study examined the longitudinal relationship of early elementary predictors to adolescent depression 7 years later. The sample consisted of 938 students who have been part of a larger longitudinal study that started in 1993. Data collected from parents, teachers, and youth self-reports on early risk factors when students were in 1st and 2nd…

  16. Inspection of Pipelines Using the First Longitudinal Guided Wave Mode

    NASA Astrophysics Data System (ADS)

    Lowe, P. S.; Sanderson, R.; Pedram, S. K.; Boulgouris, N. V.; Mudge, P.

    Inspection of cylindrical structures using the first longitudinal Ultrasonic Guided Wave (UGW) mode has so far been predominantly neglected. This is due to its attenuative and dispersive behaviour, at common UGW operating frequencies (20-100 kHz). However, with the current knowledge on the level of attenuation in the first longitudinal wave mode and dispersion compensation techniques, the first longitudinal guided wave mode no longer need to be neglected. Furthermore, the first longitudinal guided wave mode has higher number of non-axisymmetric modes compared to other axisymmetric modes in the operating frequency. This will enhance the flaw sizing capability which makes the first longitudinal guided wave mode a viable prospect for UGW inspection of cylindrical structures. This study has been performed to investigate the potential of exciting the first longitudinal guided wave mode in isolation. Numerical investigations have been conducted to investigate the pure excitation of the first longitudinal guided wave mode. It has been shown that the first longitudinal guided wave mode can be used in UGW inspection effectively in isolation by adopting transducers with out of plane vibration for excitation. This can reduces the cost and weight of UGW inspection tooling. Numerical results are empirically validated.

  17. The estimate and measurement of longitudinal wave intensity

    NASA Astrophysics Data System (ADS)

    Ruisen, Ming

    1996-08-01

    Quasi-longitudinal waves are one type of structural waves, which are important at high frequencies. This paper studies the estimate theory and measurement technique of quasi-longitudinal waves, analyzes the bias error due to the effect of bending waves. In a two-dimensional quasi-longitudinal wave field, the intensity vector is the sum of the effective intensity vector and the intensity variation vector. Its axial component is proportional to two imaginary parts of cross spectral densities and in the measurement, it is measured by a pair of two-transducer arrays. In a onedimensional quasi-longitudinal wave field, the intensity variation is zero, the intensity is proportional to only one imaginary part of a cross spectral density and it can be measured using a two-transducer array. If bending and quasi-longitudinal waves coexist and the contribution from bending waves cannot be eliminated or reduced to a certain extent, the measured quasi-longitudinal wave intensity will contain a large error. The results measured on the three-beam structure show that quasi-longitudinal wave intensity can be accurately measured using the intensity technique when bending waves are negligible in comparison with quasi-longitudinal waves.

  18. Longitudinal Research with Sexual Assault Survivors: A Methodological Review

    ERIC Educational Resources Information Center

    Campbell, Rebecca; Sprague, Heather Brown; Cottrill, Sara; Sullivan, Cris M.

    2011-01-01

    Longitudinal research designs are relatively rare in the academic literature on rape and sexual assault despite their tremendous methodological rigor and scientific utility. In the interest of promoting wider use of such methods, we conducted a methodological review of projects that have used prospective longitudinal designs to study the…

  19. Longitudinal Research with Sexual Assault Survivors: A Methodological Review

    ERIC Educational Resources Information Center

    Campbell, Rebecca; Sprague, Heather Brown; Cottrill, Sara; Sullivan, Cris M.

    2011-01-01

    Longitudinal research designs are relatively rare in the academic literature on rape and sexual assault despite their tremendous methodological rigor and scientific utility. In the interest of promoting wider use of such methods, we conducted a methodological review of projects that have used prospective longitudinal designs to study the…

  20. Learning from Longitudinal Research in Criminology and the Health Sciences

    ERIC Educational Resources Information Center

    Vanderstaay, Steven L.

    2006-01-01

    This article reviews longitudinal research within criminology and the health sciences on the relationship between reading and criminal, delinquent, or antisocial behavior. Longitudinal research in criminology, medicine, and psychology examines the role of reading within a broad set of interactive processes, connecting literacy to public health via…

  1. Objectives, Design, and History of the National Longitudinal Study.

    ERIC Educational Resources Information Center

    Davis, J. A.; Collins, Elmer

    The National Longitudinal Study of the High School Class of 1972 (NLS) is a federally supported longitudinal study of a national sample of some 23,000 young people first surveyed as high school seniors in the spring of 1972. The historical precedents of such a study include the work of Friend and Haggert in a Boston settlement house, Louis…

  2. Learning from Longitudinal Research in Criminology and the Health Sciences

    ERIC Educational Resources Information Center

    Vanderstaay, Steven L.

    2006-01-01

    This article reviews longitudinal research within criminology and the health sciences on the relationship between reading and criminal, delinquent, or antisocial behavior. Longitudinal research in criminology, medicine, and psychology examines the role of reading within a broad set of interactive processes, connecting literacy to public health via…

  3. Adolescent Psychosocial Development: A Review of Longitudinal Models and Research

    ERIC Educational Resources Information Center

    Meeus, Wim

    2016-01-01

    This review used 4 types of longitudinal models (descriptive models, prediction models, developmental sequence models and longitudinal mediation models) to identify regular patterns of psychosocial development in adolescence. Eight patterns of adolescent development were observed across countries: (1) adolescent maturation in multiple…

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

    ERIC Educational Resources Information Center

    Seo, Dong-Chul; Li, Kaigang

    2012-01-01

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

  5. Objectives, Design, and History of the National Longitudinal Study.

    ERIC Educational Resources Information Center

    Davis, J. A.; Collins, Elmer

    The National Longitudinal Study of the High School Class of 1972 (NLS) is a federally supported longitudinal study of a national sample of some 23,000 young people first surveyed as high school seniors in the spring of 1972. The historical precedents of such a study include the work of Friend and Haggert in a Boston settlement house, Louis…

  6. Adolescent Psychosocial Development: A Review of Longitudinal Models and Research

    ERIC Educational Resources Information Center

    Meeus, Wim

    2016-01-01

    This review used 4 types of longitudinal models (descriptive models, prediction models, developmental sequence models and longitudinal mediation models) to identify regular patterns of psychosocial development in adolescence. Eight patterns of adolescent development were observed across countries: (1) adolescent maturation in multiple…

  7. A Longitudinal Investigation of Individual Implementation of Educational Innovations.

    ERIC Educational Resources Information Center

    Hall, Gene E.

    Implementation is a key factor in shaping school policies. The Procedures for Adopting Educational Innovations Project conducted longitudinal studies of innovation implementation based on the Concerns-Based Adoption Model (CBAM). A key dimension of CBAM, Levels of Use of the Innovation (LoU), was assessed in three longitudinal studies over a…

  8. Future Orientation, Impulsivity, and Problem Behaviors: A Longitudinal Moderation Model

    ERIC Educational Resources Information Center

    Chen, Pan; Vazsonyi, Alexander T.

    2011-01-01

    In the current study, based on a sample of 1,873 adolescents between 11.4 and 20.9 years of age from the first 3 waves of the National Longitudinal Study of Adolescent Health, we investigated the longitudinal effects of future orientation on levels of and developmental changes in problem behaviors, while controlling for the effects by impulsivity;…

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

    ERIC Educational Resources Information Center

    Seo, Dong-Chul; Li, Kaigang

    2012-01-01

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

  10. Beyond Terman: Contemporary Longitudinal Studies of Giftedness and Talent.

    ERIC Educational Resources Information Center

    Subotnik, Rena F., Ed.; Arnold, Karen D., Ed.

    This volume presents 16 papers describing recent longitudinal studies of giftedness. Papers have the following titles and authors: (1) "Longitudinal Study of Giftedness and Talent" (Rena F. Subotnik and Karen D. Arnold); (2) "The Illinois Valedictorian Project: Early Adult Careers of Academically Talented Male High School Students" (Karen D.…

  11. A Cautionary Note on Modeling Growth Trends in Longitudinal Data

    ERIC Educational Resources Information Center

    Kuljanin, Goran; Braun, Michael T.; DeShon, Richard P.

    2011-01-01

    Random coefficient and latent growth curve modeling are currently the dominant approaches to the analysis of longitudinal data in psychology. The application of these models to longitudinal data assumes that the data-generating mechanism behind the psychological process under investigation contains only a deterministic trend. However, if a…

  12. Longitudinal Outcomes for Mathematics Achievement for Students with Learning Disabilities

    ERIC Educational Resources Information Center

    Judge, Sharon; Watson, Silvana M. R.

    2011-01-01

    Using longitudinal data from the first 6 waves of the Early Childhood Longitudinal Study-Kindergarten Cohort (ECLS-K), the authors examined mathematics achievement and growth trajectories by learning disability (LD) subgroups. The 2-level (time-student) growth curve model showed that lower levels of mathematics achievement were already evident at…

  13. Longitudinal Predictors of Very Early Chinese Literacy Acquisition

    ERIC Educational Resources Information Center

    Tong, Xiuli; McBride-Chang, Catherine; Wong, Anita M.-Y.; Shu, Hua; Reitsma, Pieter; Rispens, Judith

    2011-01-01

    This 2-year longitudinal study examined both concurrent and longitudinal relations of a variety of reading-related cognitive tasks and Chinese word reading and word dictation among 187 Hong Kong Chinese kindergarteners aged 4-6. Homophone awareness, visual skills and syllable awareness were all uniquely associated with Chinese word reading across…

  14. 46 CFR 172.095 - Intact longitudinal stability.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Intact longitudinal stability. 172.095 Section 172.095 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY SPECIAL RULES... Under Subchapter O of This Chapter § 172.095 Intact longitudinal stability. Each tank barge must be...

  15. 46 CFR 172.095 - Intact longitudinal stability.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Intact longitudinal stability. 172.095 Section 172.095 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY SPECIAL RULES... Under Subchapter O of This Chapter § 172.095 Intact longitudinal stability. Each tank barge must be...

  16. 46 CFR 172.095 - Intact longitudinal stability.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Intact longitudinal stability. 172.095 Section 172.095 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY SPECIAL RULES... Under Subchapter O of This Chapter § 172.095 Intact longitudinal stability. Each tank barge must be...

  17. 46 CFR 172.095 - Intact longitudinal stability.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Intact longitudinal stability. 172.095 Section 172.095 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY SPECIAL RULES... Under Subchapter O of This Chapter § 172.095 Intact longitudinal stability. Each tank barge must be...

  18. 46 CFR 172.095 - Intact longitudinal stability.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Intact longitudinal stability. 172.095 Section 172.095 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY SPECIAL RULES... Under Subchapter O of This Chapter § 172.095 Intact longitudinal stability. Each tank barge must be...

  19. A Cautionary Note on Modeling Growth Trends in Longitudinal Data

    ERIC Educational Resources Information Center

    Kuljanin, Goran; Braun, Michael T.; DeShon, Richard P.

    2011-01-01

    Random coefficient and latent growth curve modeling are currently the dominant approaches to the analysis of longitudinal data in psychology. The application of these models to longitudinal data assumes that the data-generating mechanism behind the psychological process under investigation contains only a deterministic trend. However, if a…

  20. A Longitudinal Investigation of Individual Implementation of Educational Innovations.

    ERIC Educational Resources Information Center

    Hall, Gene E.

    Implementation is a key factor in shaping school policies. The Procedures for Adopting Educational Innovations Project conducted longitudinal studies of innovation implementation based on the Concerns-Based Adoption Model (CBAM). A key dimension of CBAM, Levels of Use of the Innovation (LoU), was assessed in three longitudinal studies over a…

  1. The Impact of Mixing Modes on Reliability in Longitudinal Studies

    ERIC Educational Resources Information Center

    Cernat, Alexandru

    2015-01-01

    Mixed-mode designs are increasingly important in surveys, and large longitudinal studies are progressively moving to or considering such a design. In this context, our knowledge regarding the impact of mixing modes on data quality indicators in longitudinal studies is sparse. This study tries to ameliorate this situation by taking advantage of a…

  2. Van Kampen modes for bunch longitudinal motion

    SciTech Connect

    Burov, A.; /Fermilab

    2010-09-01

    Conditions for existence, uniqueness and stability of bunch steady states are considered. For the existence uniqueness problem, simple algebraic equations are derived, showing the result both for the action and Hamiltonian domain distributions. For the stability problem, van Kampen theory is used. Emerging of discrete van Kampen modes show either loss of Landau damping, or instability. This method can be applied for an arbitrary impedance, RF shape and beam distribution function Available areas on intensity-emittance plane are shown for resistive wall wake and single harmonic, bunch shortening and bunch lengthening RF configurations. Language of van Kampen modes is a powerful tool for studying beam stability. Its unique efficiency reveals itself in those complicated cases, when the dielectric function cannot be obtained, as it is for the longitudinal bunch motion. Emergence of a discrete mode means either loss of Landau damping or instability. By definition, the discrete modes lie outside the continuous incoherent spectrum, but they still may stay within the bucket. In the last case, the discrete mode would disappear after a tiny portion of resonant particles would be added. However, if the discrete mode lie outside the bucket, the Landau damping cannot be restored by tiny perturbation of the particle distribution; LLD is called radical in that case. For a given bunch emittance and RF voltage, the intensity is limited either by reduction of the bucket acceptance or by (radical) LLD. In this paper, results are presented for longitudinal bunch stability in weak head-tail approximation and resistive wall impedance; three RF configurations are studied: single harmonic, bunch shortening and bunch lengthening. It is shown that every RF configuration may be preferable, depending on the bunch emittance and intensity.

  3. Longitudinal patient-oriented outcomes in neuropathy

    PubMed Central

    Kerber, Kevin; Langa, Kenneth M.; Banerjee, Mousumi; Rodgers, Ann; McCammon, Ryan; Burke, James; Feldman, Eva

    2015-01-01

    Objective: To evaluate longitudinal patient-oriented outcomes in peripheral neuropathy over a 14-year time period including time before and after diagnosis. Methods: The 1996–2007 Health and Retirement Study (HRS)–Medicare Claims linked database identified incident peripheral neuropathy cases (ICD-9 codes) in patients ≥65 years. Using detailed demographic information from the HRS and Medicare claims, a propensity score method identified a matched control group without neuropathy. Patient-oriented outcomes, with an emphasis on self-reported falls, pain, and self-rated health (HRS interview), were determined before and after neuropathy diagnosis. Generalized estimating equations were used to assess differences in longitudinal outcomes between cases and controls. Results: We identified 953 peripheral neuropathy cases and 953 propensity-matched controls. The mean (SD) age was 77.4 (6.7) years for cases, 76.9 (6.6) years for controls, and 42.1% had diabetes. Differences were detected in falls 3.0 years before neuropathy diagnosis (case vs control; 32% vs 25%, p = 0.008), 5.0 years for pain (36% vs 27%, p = 0.002), and 5.0 years for good to excellent self-rated health (61% vs 74%, p < 0.0001). Over time, the proportion of fallers increased more rapidly in neuropathy cases compared to controls (p = 0.002), but no differences in pain (p = 0.08) or self-rated health (p = 0.9) were observed. Conclusions: In older persons, differences in falls, pain, and self-rated health can be detected 3–5 years prior to peripheral neuropathy diagnosis, but only falls deteriorates more rapidly over time in neuropathy cases compared to controls. Interventions to improve early peripheral neuropathy detection are needed, and future clinical trials should incorporate falls as a key patient-oriented outcome. PMID:26019191

  4. Longitudinal changes in lung hyperinflation in COPD

    PubMed Central

    Park, Jimyung; Lee, Chang-Hoon; Lee, Yeon Joo; Park, Jong Sun; Cho, Young-Jae; Lee, Jae Ho; Lee, Choon-Taek; Yoon, Ho Il

    2017-01-01

    Purpose COPD is characterized by an accelerated and progressive decline in forced expiratory volume in 1 second (FEV1) and lung hyperinflation. Although lung hyperinflation is the hallmark of COPD, data on the longitudinal changes in lung hyperinflation and any association with the decline in FEV1 are lacking. The aim of this study was to evaluate the longitudinal changes in lung hyperinflation and to investigate its relationship with FEV1 decline. Patients and methods We conducted a prospective cohort study and studied 176 COPD patients with annual lung volume measurements over a period of 5 years or more. We used a random coefficient model to calculate the annual changes in lung volumes and to evaluate the factors associated with changes in lung hyperinflation. Additionally, the relationship between the change in lung hyperinflation and FEV1 was assessed. Results Residual volume (RV), inspiratory capacity (IC), and total lung capacity (TLC) declined at a mean rate of 39.5, 49.6, and 63.8 mL/year, respectively. While IC/TLC declined at 0.70%/year, RV/TLC also declined at 0.35%/year. Changes in both IC/TLC and RV/TLC varied significantly. Frequent exacerbations led to an increase in RV/TLC and faster decline in IC/TLC over time. RV/TLC declined in 59.7% and increased in 40.3% of the patients. A significant negative correlation was found between the rates of change in FEV1 and RV/TLC, and the rate of decline in FEV1 was greater in patients with an increase in RV/TLC than in those with a decline in RV/TLC (54.2 vs 10.7 mL/year, P<0.001). Conclusion The rate of change in lung hyperinflation varied greatly among COPD patients. Progression of hyperinflation was associated with frequent exacerbations and a faster decline in FEV1. PMID:28223790

  5. Longitudinal gradients along a reservoir cascade

    USGS Publications Warehouse

    Miranda, L.E.; Habrat, M.D.; Miyazono, S.

    2008-01-01

    Reservoirs have traditionally been regarded as spatially independent entities rather than as longitudinal segments of a river system that are connected upstream and downstream to the river and other reservoirs. This view has frustrated advancement in reservoir science by impeding adequate organization of available information and by hindering interchanges with allied disciplines that often consider impounded rivers at the basin scale. We analyzed reservoir morphology, water quality, and fish assemblage data collected in 24 reservoirs of the Tennessee River; we wanted to describe longitudinal changes occurring at the scale of the entire reservoir series (i.e., cascade) and to test the hypothesis that fish communities and environmental factors display predictable gradients like those recognized for unimpounded rivers. We used a data set collected over a 7-year period; over 3 million fish representing 94 species were included in the data set. Characteristics such as reservoir mean depth, relative size of the limnetic zone, water retention time, oxygen stratification, thermal stratification, substrate size, and water level fluctuations increased in upstream reservoirs. Conversely, reservoir area, extent of riverine and littoral zones, access to floodplains and associated wetlands, habitat diversity, and nutrient and sediment inputs increased in downstream reservoirs. Upstream reservoirs included few, largely lacustrine, ubiquitous fish taxa that were characteristic of the lentic upper reaches of the basin. Fish species richness increased in a downstream direction from 12 to 67 species/ reservoir as riverine species became more common. Considering impoundments at a basin scale by viewing them as sections in a river or links in a chain may generate insight that is not always available when the impoundments are viewed as isolated entities. Basin-scale variables are rarely controllable but constrain the expression of processes at smaller scales and can facilitate the

  6. Psychosocial adjustment to ALS: a longitudinal study.

    PubMed

    Matuz, Tamara; Birbaumer, Niels; Hautzinger, Martin; Kübler, Andrea

    2015-01-01

    For the current study the Lazarian stress-coping theory and the appendant model of psychosocial adjustment to chronic illness and disabilities (Pakenham, 1999) has shaped the foundation for identifying determinants of adjustment to ALS. We aimed to investigate the evolution of psychosocial adjustment to ALS and to determine its long-term predictors. A longitudinal study design with four measurement time points was therefore, used to assess patients' quality of life, depression, and stress-coping model related aspects, such as illness characteristics, social support, cognitive appraisals, and coping strategies during a period of 2 years. Regression analyses revealed that 55% of the variance of severity of depressive symptoms and 47% of the variance in quality of life at T2 was accounted for by all the T1 predictor variables taken together. On the level of individual contributions, protective buffering, and appraisal of own coping potential accounted for a significant percentage in the variance in severity of depressive symptoms, whereas problem management coping strategies explained variance in quality of life scores. Illness characteristics at T2 did not explain any variance of both adjustment outcomes. Overall, the pattern of the longitudinal results indicated stable depressive symptoms and quality of life indices reflecting a successful adjustment to the disease across four measurement time points during a period of about two years. Empirical evidence is provided for the predictive value of social support, cognitive appraisals, and coping strategies, but not illness parameters such as severity and duration for adaptation to ALS. The current study contributes to a better conceptualization of adjustment, allowing us to provide evidence-based support beyond medical and physical intervention for people with ALS.

  7. Psychosocial adjustment to ALS: a longitudinal study

    PubMed Central

    Matuz, Tamara; Birbaumer, Niels; Hautzinger, Martin; Kübler, Andrea

    2015-01-01

    For the current study the Lazarian stress-coping theory and the appendant model of psychosocial adjustment to chronic illness and disabilities (Pakenham, 1999) has shaped the foundation for identifying determinants of adjustment to ALS. We aimed to investigate the evolution of psychosocial adjustment to ALS and to determine its long-term predictors. A longitudinal study design with four measurement time points was therefore, used to assess patients' quality of life, depression, and stress-coping model related aspects, such as illness characteristics, social support, cognitive appraisals, and coping strategies during a period of 2 years. Regression analyses revealed that 55% of the variance of severity of depressive symptoms and 47% of the variance in quality of life at T2 was accounted for by all the T1 predictor variables taken together. On the level of individual contributions, protective buffering, and appraisal of own coping potential accounted for a significant percentage in the variance in severity of depressive symptoms, whereas problem management coping strategies explained variance in quality of life scores. Illness characteristics at T2 did not explain any variance of both adjustment outcomes. Overall, the pattern of the longitudinal results indicated stable depressive symptoms and quality of life indices reflecting a successful adjustment to the disease across four measurement time points during a period of about two years. Empirical evidence is provided for the predictive value of social support, cognitive appraisals, and coping strategies, but not illness parameters such as severity and duration for adaptation to ALS. The current study contributes to a better conceptualization of adjustment, allowing us to provide evidence-based support beyond medical and physical intervention for people with ALS. PMID:26441696

  8. Children's food preferences: a longitudinal analysis.

    PubMed

    Skinner, Jean D; Carruth, Betty Ruth; Wendy, Bounds; Ziegler, Paula J

    2002-11-01

    To compare children's food preferences longitudinally and identify factors related to food preferences. Mothers completed the Food Preference Questionnaire for children at 2 to 3 years of age (T1), 4 years (T2), and 8 years (T3) and for themselves at T1 and T3. Both groups completed a Food Neophobia Scale at T3. 70 child/mother pairs who had participated continuously in the longitudinal study. Changes in food preferences over time were tested with paired t tests and correlations. Consistency percentages were calculated by summing the consistent matches (like/like) for each food between two time periods. Similarly, concordance percentages were calculated for child/mother pairs by summing the concordant matches for each food. General linear models were developed to identify influences on children's food preferences. Although children liked most foods, the number of liked foods did not change significantly during the 5 to 5.7 years of the study. The strongest predictors of the number of foods liked at age 8 years (R2=0.74) were the number liked at 4 years (P<.0001) and the food neophobia score (P=.0003). Newly tasted foods were more likely to be accepted between T1 and T2 than T2 and T3. Mothers' and children's food preferences were significantly but moderately related. Foods disliked by mothers tended not to be offered to children. The important role of children's early food preferences is confirmed by this study. Mothers influence children via their own preferences, which may limit foods offered to children.

  9. Distraction osteogenesis using a longitudinal corticotomy.

    PubMed

    Al-Saati, Ma'ad F; Magnussen, Robert A; Lustig, Sebastien; Testa, Rodolphe; Al-Saati, Gazal; Al-Saati, Faisal

    2012-05-01

    The purpose of this study was to evaluate whether the use of a longitudinal corticotomy (S-Z osteotomy) results in more rapid consolidation following distraction osteogenesis of short tibiae. Sixty-seven lengthening procedures were performed in 51 patients ranging in age from nine to 38 (mean 25) years. Diagnoses included short stature (32 tibiae), postpolio limb deformity (22 tibiae), osteomyelitis (three tibiae), trauma (two tibiae) and other diagnoses (eight tibiae). Forty-five lengthenings were performed via a longitudinal corticotomy, and 22 were performed via a transverse corticotomy. Patients were followed until consolidation of the regenerated bone was noted radiographically (consolidation time). The healing index (consolidation time per centimetre of lengthening) was calculated for each patient and compared between groups. The healing index was significantly lower in the S-Z group (30.8 ± 9.6 days/cm) than in the transverse corticotomy group (46.8 ± 20.2 days/cm) (p < 0.0001). Mean lengthening was 6.6 (range 2.5-12.5) cm in the S-Z group and 5.8 (range 2.0-12.0) cm in the transverse group (p = 0.28). Mean consolidation time was 6.3 ± 2.8 (range 3-16) months in the S-Z group and 8.1 ± 3.8 (range 3-13.5) months in the transverse group (p = 0.03). The S-Z osteotomy safely reduces consolidation time of regenerative bone during distraction osteogenesis in the tibia relative to a transverse corticotomy.

  10. HARVEST, a longitudinal patient record summarizer

    PubMed Central

    Hirsch, Jamie S; Tanenbaum, Jessica S; Lipsky Gorman, Sharon; Liu, Connie; Schmitz, Eric; Hashorva, Dritan; Ervits, Artem; Vawdrey, David; Sturm, Marc; Elhadad, Noémie

    2015-01-01

    Objective To describe HARVEST, a novel point-of-care patient summarization and visualization tool, and to conduct a formative evaluation study to assess its effectiveness and gather feedback for iterative improvements. Materials and methods HARVEST is a problem-based, interactive, temporal visualization of longitudinal patient records. Using scalable, distributed natural language processing and problem salience computation, the system extracts content from the patient notes and aggregates and presents information from multiple care settings. Clinical usability was assessed with physician participants using a timed, task-based chart review and questionnaire, with performance differences recorded between conditions (standard data review system and HARVEST). Results HARVEST displays patient information longitudinally using a timeline, a problem cloud as extracted from notes, and focused access to clinical documentation. Despite lack of familiarity with HARVEST, when using a task-based evaluation, performance and time-to-task completion was maintained in patient review scenarios using HARVEST alone or the standard clinical information system at our institution. Subjects reported very high satisfaction with HARVEST and interest in using the system in their daily practice. Discussion HARVEST is available for wide deployment at our institution. Evaluation provided informative feedback and directions for future improvements. Conclusions HARVEST was designed to address the unmet need for clinicians at the point of care, facilitating review of essential patient information. The deployment of HARVEST in our institution allows us to study patient record summarization as an informatics intervention in a real-world setting. It also provides an opportunity to learn how clinicians use the summarizer, enabling informed interface and content iteration and optimization to improve patient care. PMID:25352564

  11. Prospective, longitudinal assessment of developmental neurotoxicity.

    PubMed Central

    Jacobson, J L; Jacobson, S W

    1996-01-01

    Methodological issues in the design of prospective, longitudinal studies of developmental neurotoxicity in humans are reviewed. A comprehensive assessment of potential confounding influences is important in these studies because inadequate assessment of confounders can threaten the validity of causal inferences drawn from the data. Potential confounders typically include demographic background variables, alcohol and smoking during pregnancy, the quality of parental stimulation, the child's age at test, and the examiner. Exposure to other substances is assessed where significant exposure is expected in the target population. In most studies, control variables even weakly related to outcome are included in all multivariate statistical analyses, and a toxic effect is inferred only if the effect of exposure is significant after controlling for the potential confounders. Once a neurotoxic effect has been identified, suspected mediating variables may be added to the analysis to examine underlying processes or mechanisms through which the exposure may impact on developmental outcome. Individual differences in vulnerability may be examined in terms of either an additive compensatory model or a synergistic "risk and resilience" approach. Failure to detect real effects (Type II error) is of particular concern in these studies because public policy considerations make it likely that negative findings will be interpreted to mean that the exposure is safe. Important sources of Type II error include inadequate representation of highly exposed individuals, overcontrol for confounders, and inappropriate correction for multiple comparisons. Given the high cost and complexity of prospective, longitudinal investigations, cross-sectional pilot studies focusing on highly exposed individuals can be valuable for the initial identification of salient domains of impairment. PMID:9182034

  12. Compositional safety of herbicide-tolerant DAS-81910-7 cotton.

    PubMed

    Herman, Rod A; Fast, Brandon J; Johnson, Tempest Y; Sabbatini, Jane; Rudgers, Gary W

    2013-11-27

    DAS-81910-7 cotton is a transgenic event that was transformed to contain the aad-12 and pat genes. These genes code for the AAD-12 and PAT proteins, which confer tolerance to the herbicides 2,4-D and glufosinate, respectively. Crop composition studies were conducted with DAS-81910-7 cotton (both nonsprayed and sprayed with 2,4-D and glufosinate) to comply with requirements of regulatory authorities responsible for evaluating crop safety. Results indicate compositional equivalence between DAS-81910-7 cottonseed and nontransgenic cottonseed and between sprayed and nonsprayed DAS-81910-7 cottonseed. This study builds on the results from many prior studies which support the conclusion that transgenesis is less likely to unexpectedly alter the composition of crops as compared with traditional breeding.

  13. Phase 1 Clinical Trials of DAS181, an Inhaled Sialidase, in Healthy Adults

    PubMed Central

    Zenilman, Jonathan M.; Fuchs, Edward J.; Hendrix, Craig W.; Radebaugh, Christine; Jurao, Robert; Nayak, Seema U.; Hamilton, Robert G.; Griffiss, J. McLeod

    2015-01-01

    DAS181, (study drug, Fludase®) was developed for treatment of influenza and parainfluenza infections. Delivered by inhalation, DAS181 cleaves sialic acid receptors from respiratory epithelial cells. Treatment of influenza for three days with DAS181 reduced viral shedding. To increase deposition in the upper airways and decrease systemic absorption, the particle size was increased to 10 microns. We conducted two Phase I trials with three cohorts, randomized 2:1, active drug to placebo. The initial cohort got a single 20 mg dose of DAS181, or placebo; the second, 20 mg DAS181 or placebo for 10 days, and the third got 20 mg of DAS181or placebo for 3 days. Formulations differed slightly in their excipients. Subjects in the 1- and 3-day cohorts completed dosing without serious adverse events. Two subjects in the 10-day cohort stopped at Day 9 after developing respiratory and systemic symptoms, and a third experienced a decrease in FEV1 (Forced Expiratory Volume in 1 second) after the 9th dose and a further decline after the 10th dose. Plasma DAS181, in the 10-day cohort, peaked and began falling before the last dose. Antibodies, predominately IgG with neutralizing activity, were detected in 15/18 subjects by Day 30. The highest IgG concentrations were in the 10-day cohort. The respiratory adverse events occurring after seven days and rapid drug clearance during continued dosing are consistent with the induction of DAS181 antibodies. This could preclude use of this medication for longer than seven days or for repeated courses. (These studies have been registered at ClinicalTrials.gov under registration nos. NCT 00527865 and NCT 01651494.) PMID:26391974

  14. Phase 1 clinical trials of DAS181, an inhaled sialidase, in healthy adults.

    PubMed

    Zenilman, Jonathan M; Fuchs, Edward J; Hendrix, Craig W; Radebaugh, Christine; Jurao, Robert; Nayak, Seema U; Hamilton, Robert G; McLeod Griffiss, J

    2015-11-01

    DAS181, (study drug, Fludase®) was developed for treatment of influenza and parainfluenza infections. Delivered by inhalation, DAS181 cleaves sialic acid receptors from respiratory epithelial cells. Treatment of influenza for three days with DAS181 reduced viral shedding. To increase deposition in the upper airways and decrease systemic absorption, the particle size was increased to 10μm. We conducted two Phase I trials with three cohorts, randomized 2:1, active drug to placebo. The initial cohort got a single 20mg dose of DAS181, or placebo; the second, 20mg DAS181 or placebo for 10days, and the third got 20mg of DAS181 or placebo for 3days. Formulations differed slightly in their excipients. Subjects in the 1- and 3-day cohorts completed dosing without serious adverse events. Two subjects in the 10-day cohort stopped at Day 9 after developing respiratory and systemic symptoms, and a third experienced a decrease in FEV1 (Forced Expiratory Volume in 1s) after the 9th dose and a further decline after the 10th dose. Plasma DAS181, in the 10-day cohort, peaked and began falling before the last dose. Antibodies, predominately IgG with neutralizing activity, were detected in 15/18 subjects by Day 30. The highest IgG concentrations were in the 10-day cohort. The respiratory adverse events occurring after seven days and rapid drug clearance during continued dosing are consistent with the induction of DAS181 antibodies. This could preclude use of this medication for longer than seven days or for repeated courses. (These studies have been registered at ClinicalTrials.gov under registration Nos. NCT 00527865 and NCT 01651494.).

  15. Development of a Driver Alert System (DAS) for the Bradley Fighting Vehicle

    DTIC Science & Technology

    1988-07-01

    FIGHTING VEHICLE The survivability of a Bradley Fighting Vehicle (BFV) depends, in large part, on rapid response and movement in changing battle conditions...ARI Research Note 88-73 I6 0 Development of aDriver AertSystem CO (DAS) for the Bradley Fighting Vehicle * David F. Champion, Paul R. Roberson, and...System (DAS) Final Report for the Bradley Fighting Vehicle September 85 - September 87 6. PERFORMING ORG. REPORT NUMBER 7. AUTHOR(s) 6. CONTRACT OR GRANT

  16. Dimensions of integration, continuity and longitudinality in clinical clerkships.

    PubMed

    Ellaway, Rachel H; Graves, Lisa; Cummings, Beth-Ann

    2016-09-01

    Over the past few decades, longitudinal integrated clerkships (LICs) have been proposed to address many perceived short-coming of traditional block clerkships. This growing interest in LICs has raised broader questions regarding the role of integration, continuity and longitudinality in medical education. A study with complementary theoretical and empirical dimensions was conducted to derive a more precise way of defining these three underlying concepts within the design of medical education curricula. The theoretical dimension involved a thematic review of the literature on integration, continuity and longitudinality in medical education. The empirical dimension surveyed all 17 Canadian medical schools on how they have operationalised integration, continuity and longitudinality in their undergraduate programmes. The two dimensions were iteratively synthesised to explore the meaning and expression of integration, continuity and longitudinality in medical education curriculum design. Integration, continuity and longitudinality were expressed in many ways and forms, including: integration of clinical disciplines, combined horizontal integration and vertical integration, and programme-level integration. Types of continuity included: continuity of patients, continuity of teaching, continuity of location and peer continuity. Longitudinality focused on connected or repeating episodes of training or on connecting activities, such as encounter logging across educational episodes. Twelve of the 17 schools were running an LIC of some kind, although only one school had a mandatory LIC experience. An ordinal scale of uses of integration, continuity and longitudinality during clerkships was developed, and new definitions of these concepts in the clerkship context were generated. Different clerkship designs embodied different forms and levels of integration, continuity and longitudinality. A dichotomous view of LICs and rotation-based clerkships was found not to represent

  17. Construção de um catálogo de aglomerados abertos para estudo da dinâmica da estrutura espiral da Galáxia

    NASA Astrophysics Data System (ADS)

    Carlos, I. M.; Lépine, J. R. D.

    2003-08-01

    Os aglomerados abertos são objetos de grande valor para o estudo da dinâmica da Galáxia devido esses objetos terem uma faixa de idade relativamente ampla. O trabalho visa estudar a dinâmica da estrutura espiral da Galáxia principalmente através do uso desses aglomerados, uma vez que o estudo da cinemática desses objetos é fundamental para esse objetivo. Nosso grupo trabalha no sentido de construir uma base de dados de aglomerados abertos contendo coordenadas, distância, idade, movimentos próprios e velocidades radiais e já disponibiliza uma nova versão do catálogo de aglomerados abertos o qual é uma compilação de edições anteriores, principalmente Lynga (1987), Mermilliod (1995) e ESO-B (Lauberts 1982). Nossa amostra possui cerca de 1630 aglomerados, mas nem todos os parâmetros acima citados foram determinados em sua totalidade. Para determinarmos esses parâmetros, derivamos as cores intrínsecas das estrelas membro de cada aglomerado a partir de seus tipos espectrais (busca feita no SIMBAD) obtendo assim o excesso de cor individual. A distribuição dos excessos de cor foi então utilizada para derivarmos o avermelhamento médio para cada aglomerado. De maneira similar, os tipos espectrais foram usados para estimar as magnitudes absolutas, e com as magnitudes absolutas e aparentes determinamos a respectiva distribuição do módulo de distância e finalmente a distância. Para determinar as idades foram confeccionados os diagramas cor-magnitude das estrelas de cada aglomerado onde foram superpostas a Seqüência Principal de Idade Zero (ZAMS). Superpomos a ZAMS de Schmidt-Kaler e isócronas de composição solar. Essas isócronas foram usadas para determinação das idades dos aglomerados. Uma vez que não temos ainda resultados finais, apresentamos então alguns diagramas cor-magnitude os quais foram usados para determinação, principalmente, da distância e idade dos aglomerados.

  18. Longitudinal Section AA/South ElevationPreRehabilitation 2009; Longitudinal Section BB/PostRehabilitation 2010 ...

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

    Longitudinal Section A-A/South Elevation-Pre-Rehabilitation 2009; Longitudinal Section B-B/Post-Rehabilitation 2010 - Gilpin's Falls Covered Bridge, Spanning North East Creek at Former (Bypassed) Section of North East Road (SR 272), North East, Cecil County, MD

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

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-24

    ... Agency Information Collection Activities; Comment Request; Early Childhood Longitudinal Study... notice will be considered public records. Title of Collection: Early Childhood Longitudinal Study... Childhood Longitudinal Study, Kindergarten Class of 2010-11 (ECLS-K:2011), sponsored by the National...

  20. Comparing Cognitive, Metacognitive, and Acceptance and Commitment Therapy Models of Depression: a Longitudinal Study Survey.

    PubMed

    Ruiz, Francisco J; Odriozola-González, Paula

    2015-06-16

    This study analyzed the interrelationships between key constructs of cognitive therapy (CT; depressogenic schemas), metacognitive therapy (MCT; dysfunctional metacognitive beliefs), and acceptance and commitment therapy (ACT; psychological inflexibility) in the prediction of depressive symptoms. With a lapse of nine months, 106 nonclinical participants responded twice to an anonymous online survey containing the following questionnaires: the Depression subscale of the Depression Anxiety and Stress Scales (DASS), the Dysfunctional Attitude Scale Revised (DAS-R), the Positive beliefs, Negative beliefs and Need to control subscales of the Metacognitions Questionnaire-30 (MCQ-30), and the Acceptance and Action Questionnaire - II (AAQ-II). Results showed that when controlling for baseline levels of depressive symptoms and demographic variables, psychological inflexibility longitudinally mediated the effect of depressogenic schemas (path ab = .023, SE = .010; 95% BC CI [.008, .048]) and dysfunctional metacognitive beliefs on depressive symptoms (positive metacognitive beliefs: path ab = .052, SE = .031; 95% BC CI [.005, .134]; negative metacognitive beliefs: path ab = .087, SE = .049; 95% BC CI [.016, .214]; need to control: path ab = .087, SE = .051; 95% BC CI [.013, .220]). Results are discussed emphasizing the role of psychological inflexibility in the CT and MCT models of depression.

  1. VIIRS ocean color data visualization and processing with IDL-based NOAA-SeaDAS

    NASA Astrophysics Data System (ADS)

    Wang, Xiaolong; Liu, Xiaoming; Jiang, Lide; Wang, Menghua; Sun, Junqiang

    2014-11-01

    The NOAA Sea-viewing Data Analysis System (NOAA-SeaDAS) is an Interactive Data Language (IDL)-based satellite data visualization, analysis, and processing system based on the version 6.4 of the NASA's Sea-viewing Wide Field-ofview (SeaWiFS) Data Analysis System (SeaDAS) released in 2012. NOAA-SeaDAS inherited all the original functionalities of SeaDAS 6.4 and was upgraded with many new functions and new sensor supports, particularly the support of the Visible Infrared Imaging Radiometer Suite (VIIRS) onboard the Suomi National Polar-Orbiting Partnership (SNPP). The main goal of the NOAA-SeaDAS development is primarily in support of NOAA ocean color team's calibration and validation activities. The current version of NOAA-SeaDAS can visualize, analyze, and process VIIRS Sensor Data Records (SDR or Level-1B data) produced by the NOAA Interface Data Processing System (IDPS), ocean color Environmental Data Records (EDR or Level-2 data) produced by the NOAA Multi-Sensor Level-1 to Level- 2 (MSL12) ocean color data processing system, and Level-3 data binned or mapped from Level-2 data produced by NOAA-MSL12. NOAA-SeaDAS is currently serving an active IDL user group at NOAA and will serve other institutions and universities in the future. The goal is to allow various scientific users to visualize, analyze, and process VIIRS data from Level-1B through Level-2 and Level-3. In addition, NOAA-SeaDAS can also visualize satellite images from the Korean Geostationary Ocean Color Imager (GOCI), as well as many other satellite ocean color sensors, e.g., SeaWiFS, the Moderate Resolution Imaging Spectroradiometer (MODIS), etc. NOAA-SeaDAS is under constant development to create new system functionalities and enhance user experience. With constantly increasing volume in the global ocean color data archive, NOAA-SeaDAS will play an important role in support of global marine environment data analysis and various scientific applications.

  2. Longitudinal phase space tomography with space charge

    NASA Astrophysics Data System (ADS)

    Hancock, S.; Lindroos, M.; Koscielniak, S.

    2000-12-01

    Tomography is now a very broad topic with a wealth of algorithms for the reconstruction of both qualitative and quantitative images. In an extension in the domain of particle accelerators, one of the simplest algorithms has been modified to take into account the nonlinearity of large-amplitude synchrotron motion. This permits the accurate reconstruction of longitudinal phase space density from one-dimensional bunch profile data. The method is a hybrid one which incorporates particle tracking. Hitherto, a very simple tracking algorithm has been employed because only a brief span of measured profile data is required to build a snapshot of phase space. This is one of the strengths of the method, as tracking for relatively few turns relaxes the precision to which input machine parameters need to be known. The recent addition of longitudinal space charge considerations as an optional refinement of the code is described. Simplicity suggested an approach based on the derivative of bunch shape with the properties of the vacuum chamber parametrized by a single value of distributed reactive impedance and by a geometrical coupling coefficient. This is sufficient to model the dominant collective effects in machines of low to moderate energy. In contrast to simulation codes, binning is not an issue since the profiles to be differentiated are measured ones. The program is written in Fortran 90 with high-performance Fortran extensions for parallel processing. A major effort has been made to identify and remove execution bottlenecks, for example, by reducing floating-point calculations and recoding slow intrinsic functions. A pointerlike mechanism which avoids the problems associated with pointers and parallel processing has been implemented. This is required to handle the large, sparse matrices that the algorithm employs. Results obtained with and without the inclusion of space charge are presented and compared for proton beams in the CERN protron synchrotron booster. Comparisons

  3. Longitudinal determinants of substance use disorders.

    PubMed

    Brook, Judith S; Lee, Jung Yeon; Rubenstone, Elizabeth; Finch, Stephen J; Seltzer, Nathan; Brook, David W

    2013-12-01

    Substance use and substance use disorders (SUDs) have been linked with marital discord. Relatively little is known, however, about the antecedents of SUDs, the mediators of these factors over time, or their associations with the spousal/partner relationship among urban adults. A better understanding of the longitudinal pathways to marital conflict and to SUDs should help prevention and intervention programs target their precursors within the developmental period in which they occur. The present study, therefore, examined the longitudinal predictors of an unsupportive spousal/partner relationship and SUDs among a community sample of urban African American and Puerto Rican adults from East Harlem, NY. Participants (N = 816) completed structured questionnaires at five time waves, from adolescence to adulthood (mean ages = 14, 19, 24, 29, and 32 years). Structural equation modeling examined the effects of earlier environmental and social stressors and intrapersonal and interpersonal factors on later SUDs in adulthood. There was a good fit of the structural equation model (CFI = 0.91; RMSEA = 0.06; and SRMR = 0.06), which revealed three main pathways from adolescence to the spousal/partner relationship and SUDs in adulthood. One pathway linked a weak parent-adolescent attachment relationship with the participant's psychological symptoms in emerging adulthood (p < 0.01), which in turn were related to affiliation with deviant and drug-using peers, also in emerging adulthood (p < 0.001). Peer deviance and drug use were associated with the participant's substance use in young adulthood (p < 0.001), which predicted both an unsupportive spousal/partner relationship (p < 0.05) and SUDs (p < 0.001) later in adulthood. Other pathways highlighted the continuity of psychological symptoms as related to both substance use in young adulthood (p < 0.001) and an unsupportive spousal/partner relationship in adulthood (p < 0.001). Findings

  4. Longitudinal static stability requirements for wing in ground effect vehicle

    NASA Astrophysics Data System (ADS)

    Yang, Wei; Yang, Zhigang; Collu, Maurizio

    2015-06-01

    The issue of the longitudinal stability of a WIG vehicle has been a very critical design factor since the first experimental WIG vehicle has been built. A series of studies had been performed and focused on the longitudinal stability analysis. However, most studies focused on the longitudinal stability of WIG vehicle in cruise phase, and less is available on the longitudinal static stability requirement of WIG vehicle when hydrodynamics are considered: WIG vehicle usually take off from water. The present work focuses on stability requirement for longitudinal motion from taking off to landing. The model of dynamics for a WIG vehicle was developed taking into account the aerodynamic, hydrostatic and hydrodynamic forces, and then was analyzed. Following with the longitudinal static stability analysis, effect of hydrofoil was discussed. Locations of CG, aerodynamic center in pitch, aerodynamic center in height and hydrodynamic center in heave were illustrated for a stabilized WIG vehicle. The present work will further improve the longitudinal static stability theory for WIG vehicle.

  5. Time Resolved Imaging of Longitudinal Modulations in Intense Beams

    NASA Astrophysics Data System (ADS)

    Tian, Kai

    2007-11-01

    The longitudinal evolution of high intensity beams is not well understood despite its importance to the success of such applications as free electron lasers and light sources, heavy ion inertial fusion, and high energy colliders. For example any amplification of current modulations in an FEL photoinjector can lead to unwanted coherent synchrotron radiation further downstream in compression chicanes or bends. A significant factor usually neglected is the coupling to the transverse dynamics which can strongly affect the longitudinal evolution. Previous experiments at the University of Maryland have revealed much about the longitudinal physics of space-charge dominated beams by monitoring the evolution of longitudinal perturbations. For the first time, experimental results are presented here which reveal the effect of longitudinal perturbations on the transverse beam distribution, with the aid of several new diagnostics that capture detailed time-resolved density images. A longitudinal modulation of the particle density is deliberately generated at the source, and its evolution is tracked downstream using a number of diagnostics such as current monitors, high-resolution energy analyzers, as well as the transverse imaging devices. The latter consist of a high-resolution 16-bit gated camera coupled with very fast emitters such as prompt optical transition radiation (OTR) from an alumina screen, or fast Phosphor screens with 3-ns time resolution. Simulations using the particle-in-cell code WARP are applied to cross-check the experimental results. These experiments and especially the comparisons to simulation represent significant progress towards understanding the longitudinal physics of intense beams.

  6. Inhibition of neuraminidase inhibitor-resistant influenza virus by DAS181, a novel sialidase fusion protein.

    PubMed

    Triana-Baltzer, Gallen B; Gubareva, Larisa V; Klimov, Alexander I; Wurtman, David F; Moss, Ronald B; Hedlund, Maria; Larson, Jeffrey L; Belshe, Robert B; Fang, Fang

    2009-11-06

    Antiviral drug resistance for influenza therapies remains a concern due to the high prevalence of H1N1 2009 seasonal influenza isolates which display H274Y associated oseltamivir-resistance. Furthermore, the emergence of novel H1N1 raises the potential that additional reassortments can occur, resulting in drug resistant virus. Thus, additional antiviral approaches are urgently needed. DAS181 (Fludase), a sialidase fusion protein, has been shown to have inhibitory activity against a large number of seasonal influenza strains and a highly pathogenic avian influenza (HPAI) strain (H5N1). Here, we examine the in vitro activity of DAS181 against a panel of 2009 oseltamivir-resistant seasonal H1N1 clinical isolates. The activity of DAS181 against nine 2009, two 2007, and two 2004 clinical isolates of seasonal IFV H1N1 was examined using plaque number reduction assay on MDCK cells. DAS181 strongly inhibited all tested isolates. EC50 values remained constant against isolates from 2004, 2007, and 2009, suggesting that there was no change in DAS181 sensitivity over time. As expected, all 2007 and 2009 isolates were resistant to oseltamivir, consistent with the identification of the H274Y mutation in the NA gene of all these isolates. Interestingly, several of the 2007 and 2009 isolates also exhibited reduced sensitivity to zanamivir, and accompanying HA mutations near the sialic acid binding site were observed. DAS181 inhibits IFV that is resistant to NAIs. Thus, DAS181 may offer an alternative therapeutic option for seasonal or pandemic IFVs that become resistant to currently available antiviral drugs.

  7. Longitudinal vibration of cracked beams under magnetic field

    NASA Astrophysics Data System (ADS)

    Güven, Uğur

    2016-12-01

    Longitudinal vibration of a cracked beam subjected to the transverse magnetic field is addressed. One dimensional wave theory is used and the crack part of the beam is modelled as by a linear spring, in this analysis. The obtained explicit solution, for clamped-free and clamped-clamped boundary conditions, is illustrated as graphically. It is generally seen that the longitudinal frequencies increase with increase of the intensity of magnetic field. However, the results of the analysis reveal that the transverse magnetic field has a more significant effect on the variation of longitudinal vibration frequency under the clamped-clamped boundary conditions.

  8. Longitudinal emittance growth due to nonlinear space charge effect

    NASA Astrophysics Data System (ADS)

    Lau, Y. Y.; Yu, Simon S.; Barnard, John J.; Seidl, Peter A.

    2012-03-01

    Emittance posts limits on the key requirements of final pulse length and spot size on target in heavy ion fusion drivers. In this paper, we show studies on the effect of nonlinear space charge on longitudinal emittance growth in the drift compression section. We perform simulations, using the 3D PIC code WARP, for a high current beam under conditions of bends and longitudinal compression. The linear growth rate for longitudinal emittance turns out to depend only on the peak line charge density, and is independent of pulse length, velocity tilt, and/or the pipe and beam size. This surprisingly simple result is confirmed by simulations and analytic calculations.

  9. Extracting longitudinal shower development information from crystal calorimetry plus tracking

    SciTech Connect

    Brown, David; Brown, D.N.; Ilic, J.; Mohanty, G.B.

    2007-11-01

    We present an approach to derive longitudinal shower development information from the longitudinally unsegmented BABAR electromagnetic calorimeter by using tracking information. Our algorithm takes advantage of the good three-dimensional tracking resolution of BABAR, which provides an independent geometric constraint on the shower as measured in the BABAR crystal calorimeter. We show that adding the derived longitudinal shower development information to standard particle identification algorithms significantly improves the low-momentum separation of pions from electrons and muons. We also verify that the energy dependence of the electromagnetic shower development we measure is consistent with the prediction of a standard electromagnetic shower model.

  10. Multiplexed multi-longitudinal mode fiber laser sensor.

    PubMed

    Huang, Long; Wang, Peng; Gao, Liang; Zhang, Tingting; Chen, Xiangfei

    2014-10-20

    A multiplexed multi-longitudinal mode fiber laser sensor system is proposed and demonstrated. By incorporating two matched wavelength division multiplexers (WDMs) and a semiconductor optical amplifier (SOA) into a fiber laser cavity, multiwavelength oscillation is established. Each wavelength corresponding to one channel of WDMs contains multi-longitudinal modes. The multiwavelength output of the laser is directed to another WDM which functions as a demultiplexer. By monitoring the longitudinal mode beat frequency generated at photodetectors following the WDM, the sensing information can be demodulated. Preliminary results for multiplexing two sensors measuring strain and temperature are presented to verify the principle of the system.

  11. Signal processing for longitudinal parameters of the Tevatron beam

    SciTech Connect

    Pordes, S.; Crisp, J.; Fellenz, B.; Flora, R.; Para, A.; Tollestrup, A.V.; /Fermilab

    2005-05-01

    We describe the system known as the Tevatron SBD [1] which is used to provide information on the longitudinal parameters of coalesced beam bunches in the Tevatron. The system has been upgraded over the past year with a new digitizer and improved software. The quantities provided for each proton and antiproton bunch include the intensity, the longitudinal bunch profile, the timing of the bunch with respect to the low-level RF, the momentum spread and the longitudinal emittance. The system is capable of 2 Hz operation and is run at 1 Hz.

  12. Uncorrelated Energy Spread and Longitudinal Emittance of a Photoinjector Beam

    SciTech Connect

    Huang, Z; Dowell, D.; Emma, P.; Limborg-Deprey, C.; Stupakov, G.; Wu, J.; /SLAC

    2005-05-25

    Longitudinal phase space properties of a photoinjector beam are important in many areas of high-brightness beam applications such as bunch compression, transverse-to-longitudinal emittance exchange, and high-gain free-electron lasers. In this paper, we discuss both the rf and the space charge contributions to the uncorrelated energy spread of the beam generated from a laser-driven rf gun. We compare analytical expressions for the uncorrelated energy spread and the longitudinal emittance with numerical simulations and recent experimental results.

  13. A Semiparametric Marginalized Model for Longitudinal Data with Informative Dropout.

    PubMed

    Liu, Mengling; Lu, Wenbin

    2012-01-01

    We propose a marginalized joint-modeling approach for marginal inference on the association between longitudinal responses and covariates when longitudinal measurements are subject to informative dropouts. The proposed model is motivated by the idea of linking longitudinal responses and dropout times by latent variables while focusing on marginal inferences. We develop a simple inference procedure based on a series of estimating equations, and the resulting estimators are consistent and asymptotically normal with a sandwich-type covariance matrix ready to be estimated by the usual plug-in rule. The performance of our approach is evaluated through simulations and illustrated with a renal disease data application.

  14. Io: longitudinal distribution of sulfur dioxide frost.

    PubMed

    1980-11-14

    Twenty spectra of Io (0.26 to 0.33 micrometer), acquired with the International Ultraviolet Explorer spacecraft, have been studied. There is a strong ultraviolet absorption shortward of 0.33 micrometer that is consistent with earlier ground-based spectrophotometry; its strength is strongly dependent on Io's rotational phase angle at the time of observation. This spectral feature and its variation are interpreted as indicative of a longitudinal variation in the distribution of sulfur dioxide frost on Io. The frost is most abundant at orbital longitudes 72 degrees to 137 degrees and least abundant at longitudes 250 degrees to 323 degrees . Variations in spectral reflectivity between 0.4 and 0.5 micrometer, reported in earlier ground-based spectral studies, correlate inversely with variations in reflectivity between 0.26 and 0.33 micrometer. It is concluded that this is because the Io surface component with the highest visible reflectivity (sulfur dioxide frost) has the lowest ultraviolet reflectivity. At least one other component is present and may be sulfur allotropes or alkali sulfides. This model is consistent with ground-based ultraviolet, visible, and infrared spectrophotometry. Comparison with Voyager color photographs indicates that the sulfur dioxide frost is in greatest concentration in the "white" areas on Io and the other sulfurous components are in greatest concentration in the "red" areas.

  15. Longitudinal Relationships Between Resources, Motivation, and Functioning

    PubMed Central

    Emery, Lisa; Neupert, Shevaun D.

    2012-01-01

    Objectives. We investigated how fluctuations and linear changes in health and cognitive resources influence the motivation to engage in complex cognitive activity and the extent to which motivation mediated the relationship between changing resources and cognitively demanding activities. Method. Longitudinal data from 332 adults aged 20–85 years were examined. Motivation was assessed using a composite of Need for Cognition and Personal Need for Structure and additional measures of health, sensory functioning, cognitive ability, and self-reported activity engagement. Results. Multilevel modeling revealed that age-typical changes in health, sensory functions, and ability were associated with changes in motivation, with the impact of declining health on motivation being particularly strong in older adulthood. Changes in motivation, in turn, predicted involvement in cognitive and social activities as well as changes in cognitive ability. Finally, motivation was observed to partially mediate the relationship between changes in resources and cognitively demanding activities. Discussion. Our results suggest that motivation may play an important role in determining the course of cognitive change and involvement in cognitively demanding everyday activities in adulthood. PMID:21926400

  16. Longitudinal validation of psychosis risk screening tools.

    PubMed

    Kline, Emily; Thompson, Elizabeth; Demro, Caroline; Bussell, Kristin; Reeves, Gloria; Schiffman, Jason

    2015-07-01

    The development of widely used interview tools has helped to standardize the criteria for a "clinical high risk" syndrome, thus enabling advances in efforts to develop interventions for this phase of illness. These assessments, however, are burdensome to administer and not likely to be adopted for widespread use. Scalable early intervention depends on the availability of brief, low-cost assessment tools that can serve to screen populations of interest or triage treatment-seekers toward specialized care. The current study examines the sensitivity, specificity, and predictive strength of three self-report measures (Prime Screen-Revised, Prodromal Questionnaire-Brief, and Youth Psychosis at Risk Questionnaire-Brief) with regard to psychosis onset and symptom persistence over six months of follow-up within an indicated sample of 54 adolescents and young adults ages 12-22. Within this sample, all three measures demonstrated excellent sensitivity to emerging psychosis and strong agreement with clinician evaluations of attenuated psychosis symptoms. Additionally, all screeners obtained negative predictive values of 1.00 with regard to psychosis onset, indicating that an individual scoring below the recommended threshold score would be extremely unlikely to develop psychosis over the following six months. The longitudinal validation of psychosis risk screening tools constitutes an important step toward establishing a standard of care for early identification and monitoring in this vulnerable population.

  17. SORL1 predicts longitudinal cognitive change

    PubMed Central

    Reynolds, Chandra A.; Zavala, Catalina; Gatz, Margaret; Vie, Loryana; Johansson, Boo; Malmberg, Bo; Ingelsson, Erik; Prince, Jonathan A.; Pedersen, Nancy L.

    2013-01-01

    The gene encoding sortilin receptor 1 (SORL1) has been associated with Alzheimer’s disease risk. We examined 15 SORL1 variants and SNP-set risk scores in relation to longitudinal verbal, spatial, memory and perceptual speed performance, testing for age trends and sex-specific effects. Altogether, 1609 individuals from three population-based Swedish twin studies were assessed up to five times across 16 years. Controlling for APOE, multiple simple and sex-moderated associations were observed for spatial, episodic memory and verbal trajectories (p = 1.25E-03 to p = 4.83E-02). Five variants (rs11600875, rs753780, rs7105365, rs11820794, rs2070045) were associated across domains. Notably, in those homozygous for rs2070045 risk alleles, males demonstrated initially favorable performance but accelerating declines, while females showed overall lower performance. SNP-set risk scores predicted spatial (Card Rotations, p = 5.92E-03) and episodic memory trajectories (Thurstone Picture Memory, p = 3.34E-02), where higher risk scores benefitted men’s versus women’s performance up to age 75 but with accelerating declines. SORL1 is associated with cognitive aging, and may contribute differentially to change in men and women. PMID:23318115

  18. Longitudinal maxillary growth in Down syndrome patients.

    PubMed

    Alió, Juan; Lorenzo, José; Iglesias, M Carmen; Manso, Francisco J; Ramírez, Eva M

    2011-03-01

    To assess maxillary growth in a sample of patients diagnosed with Down syndrome (DS). The sample comprised 47 subjects (25 boys, 22 girls) with DS. All patients had at least two radiographs that showed the cranial base. To obtain comparisons among age groups, the sample was divided into three groups: prepubescent (8-11 years old), pubescent (12-14 years old), and postpubescent (15-18 years old). A control group included 38 subjects without DS (22 boys, 16 girls) who were part of a longitudinal growth sample. Computerized cephalometric analysis was performed on all subjects, and cephalometric superimpositions were made. Two-way analysis of variance (ANOVA) was used to study the overall changes between groups. In addition, one-way ANOVA and the Duncan multiple-range test were used to analyze possible differences in the age groups. Sagittal maxillary growth in DS patients was constant from the age of 8 to 18 years; there was an average increase of 0.12 mm/year, measured at the level of point A. In the vertical plane it grows at an average rate of 0.62 mm/year and 0.70 mm/year, measured at the level of the ANS and PNS, respectively. The maxilla in the DS group shows hypoplasia in the vertical plane and the sagittal plane, and there was a mean deficit of almost 10 mm in the latter.

  19. Longitudinal performance of an implantable vestibular prosthesis

    PubMed Central

    Phillips, Christopher; Ling, Leo; Oxford, Trey; Nowack, Amy; Nie, Kaibao; Rubinstein, Jay T.; Phillips, James O.

    2014-01-01

    Loss of vestibular function may be treatable with an implantable vestibular prosthesis that stimulates semicircular canal afferents with biphasic pulse trains. Several studies have demonstrated short-term activation of the vestibulo-ocular reflex (VOR) with electrical stimulation. Fewer long-term studies have been restricted to small numbers of animals and stimulation designed to produce adaptive changes in the electrically elicited response. This study is the first large consecutive series of implanted rhesus macaque to be studied longitudinally using brief stimuli designed to limit adaptive changes in response, so that the efficacy of electrical activation can be studied over time, across surgeries, canals and animals. The implantation of a vestibular prosthesis in animals with intact vestibular end organs produces variable responses to electrical stimulation across canals and animals, which change in threshold for electrical activation of eye movements and in elicited slow phase velocities over time. These thresholds are consistently lower, and the slow phase velocities higher, than those obtained in human subjects. The changes do not appear to be correlated with changes in electrode impedance. The variability in response suggests that empirically derived transfer functions may be required to optimize the response of individual canals to a vestibular prosthesis, and that this function may need to be remapped over time. PMID:25245586

  20. Adolescent stress and coping: a longitudinal study.

    PubMed

    Groër, M W; Thomas, S P; Shoffner, D

    1992-06-01

    The purpose of this longitudinal panel study was to investigate developmental and gender influences on stress and coping in adolescents attending a suburban high school in Tennessee. Data were collected from the same 167 subjects during the freshman year and again during the senior year. Life events stress was measured through the Adolescent Life Change Event Scale (ALCES) and ways of coping were categorized from data gathered from an open-ended questionnaire. Girls reported more life events stress at both testings than boys. Life events stress was greater at senior testing for both girls and boys, but girls' scores increased more. The "gender intensification" phenomenon may account for the greater disparity in types of stress reported by boys and girls as seniors. Girls generally reported more life events associated with interpersonal and family relationships. Both girls and boys reported coping with stress mostly through active distraction techniques such as exercise. However, girls' use of active distraction decreased over time, while passive distraction increased. Self-destructive and aggressive coping behaviors increased for boys. There were no relationships between amounts or types of life events stress and ways of coping for subjects at either time.

  1. [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.

  2. Longitudinal dynamic stability of a shuttle vehicle.

    NASA Technical Reports Server (NTRS)

    Vinh, N. X.; Laitone, E. V.

    1972-01-01

    Analytical study of the longitudinal dynamic stability of a nonrolling, lifting vehicle gliding at hypersonic speeds. The analysis applies to shuttle vehicles designed for operating up to the rim of a planetary atmosphere. A general nondimensional time transformation is introduced to derive a unified second-order linear differential equation for the angle of attack, valid for all types of reentry of a general type of vehicle. The stability of motion is discussed for two fundamental regimes of flight that are based on widely different assumptions. For near ballistic entry along a straight line trajectory, the equation reduces to a confluent hypergeometric equation, the solution of which can be expressed in terms of Whittaker's function. Using a theorem in the theory of stability of differential equations, criteria for damped oscillations are derived. It is shown that the aerodynamic criteria for stability are the same as for the case of ballistic entry. In addition, for each vehicle configuration, and specified planetary atmosphere, there exists an altitude range where the angle of attack frequency is nearly equal to the orbital frequency causing instability in pitch. This resonance instability is due to the ellipticity of the orbit. Criteria for eccentricity instability are derived.

  3. Longitudinal wheel slip during ABS braking

    NASA Astrophysics Data System (ADS)

    Hartikainen, Lassi; Petry, Frank; Westermann, Stephan

    2015-02-01

    Anti-lock braking system (ABS) braking tests with two subcompact passenger cars were performed on dry and wet asphalt, as well as on snow and ice surfaces. The operating conditions of the tyres in terms of wheel slip were evaluated using histograms of the wheel slip data. The results showed different average slip levels for different road surfaces. It was also found that changes in the tyre tread stiffness affected the slip operating range through a modification of the slip value at which the maximum longitudinal force is achieved. Variation of the tyre footprint length through modifications in the inflation pressure affected the slip operating range as well. Differences in the slip distribution between vehicles with different brake controllers were also observed. The changes in slip operating range in turn modified the relative local sliding speeds between the tyre and the road. The results highlight the importance of the ABS controller's ability to adapt to changing slip-force characteristics of tyres and provide estimates of the magnitude of the effects of different tyre and road operating conditions.

  4. Dual imputation model for incomplete longitudinal data.

    PubMed

    Jolani, Shahab; Frank, Laurence E; van Buuren, Stef

    2014-05-01

    Missing values are a practical issue in the analysis of longitudinal data. Multiple imputation (MI) is a well-known likelihood-based method that has optimal properties in terms of efficiency and consistency if the imputation model is correctly specified. Doubly robust (DR) weighing-based methods protect against misspecification bias if one of the models, but not necessarily both, for the data or the mechanism leading to missing data is correct. We propose a new imputation method that captures the simplicity of MI and protection from the DR method. This method integrates MI and DR to protect against misspecification of the imputation model under a missing at random assumption. Our method avoids analytical complications of missing data particularly in multivariate settings, and is easy to implement in standard statistical packages. Moreover, the proposed method works very well with an intermittent pattern of missingness when other DR methods can not be used. Simulation experiments show that the proposed approach achieves improved performance when one of the models is correct. The method is applied to data from the fireworks disaster study, a randomized clinical trial comparing therapies in disaster-exposed children. We conclude that the new method increases the robustness of imputations.

  5. Longitudinal Waves Organize and Control Plants

    NASA Astrophysics Data System (ADS)

    Wagner, Orvin

    2002-03-01

    Since the discovery of longitudinal waves in plants (W-waves)in 1988 I have taken data related to influences of these waves. These data include spacings betweenstructures on plants,sap flow data, electrical data from probes traceable to effects produced by these waves, data related to the influences of gravity, data related to these waves traveling between plants and on and on. All of the data suggest that the waves provide a basis for a unified theory for plant growth and development. They likely provide a basis for growth and development for all life. The wave influences are present on the microscopic level in live plants but may not show in the microscopic pieces of material often scrutinized by the usual researcher. It is this author's conclusion that the waves mentioned are important in all life and provide what we call life which has been so difficult to pinpoint in previous work. The waves show in dead material but generally are of a much smaller amplitude in the resonating live material. In the wave theory one might compare something alive to a properly operating laser. See the Wagner web site.

  6. Automatic parcellation of longitudinal cortical surfaces

    NASA Astrophysics Data System (ADS)

    Alassaf, Manal H.; Hahn, James K.

    2015-03-01

    We present a novel automatic method to parcellate the cortical surfaces of the neonatal brain longitudinal atlas at different stages of development. A labeled brain atlas of newborn at 41 weeks gestational age (GA) is used to propagate labels of anatomical regions of interest to an unlabeled spatio-temporal atlas, which provides a dynamic model of brain development at each week between 28-44 GA weeks. First, labels from the cortical volume of the labeled newborn brain are propagated to an age-matched cortical surface from the spatio-temporal atlas. Then, labels are propagated across the cortical surfaces of each week of the spatio-temporal atlas by registering successive cortical surfaces using a novel approach and an energy optimization function. This procedure incorporates local and global, spatial and temporal information when assigning the labels to each surface. The result is a complete parcellation of 17 neonatal brain surfaces of the spatio-temporal atlas with similar points per labels distributions across weeks.

  7. NASA Planetary Science Summer School: Longitudinal Study

    NASA Astrophysics Data System (ADS)

    Giron, Jennie M.; Sohus, A.

    2006-12-01

    NASA’s Planetary Science Summer School is a program designed to prepare the next generation of scientists and engineers to participate in future missions of solar system exploration. The opportunity is advertised to science and engineering post-doctoral and graduate students with a strong interest in careers in planetary exploration. Preference is given to U.S. citizens. The “school” consists of a one-week intensive team exercise learning the process of developing a robotic mission concept into reality through concurrent engineering, working with JPL’s Advanced Project Design Team (Team X). This program benefits the students by providing them with skills, knowledge and the experience of collaborating with a concept mission design. A longitudinal study was conducted to assess the impact of the program on the past participants of the program. Data collected included their current contact information, if they are currently part of the planetary exploration community, if participation in the program contributed to any career choices, if the program benefited their career paths, etc. Approximately 37% of 250 past participants responded to the online survey. Of these, 83% indicated that they are actively involved in planetary exploration or aerospace in general; 78% said they had been able to apply what they learned in the program to their current job or professional career; 100% said they would recommend this program to a colleague.

  8. Analysis of critically refracted longitudinal waves

    NASA Astrophysics Data System (ADS)

    Pei, Ning; Bond, Leonard J.

    2015-03-01

    Fabrication processes, such as, welding, forging, and rolling can induce residual stresses in metals that will impact product performance and phenomena such as cracking and corrosion. To better manage residual stress tools are needed to map their distribution. The critically refracted ultrasonic longitudinal (LCR) wave is one such approach that has been used for residual stress characterization. It has been shown to be sensitive to stress and less sensitive to the effects of the texture of the material. Although the LCR wave is increasingly widely applied, the factors that influence the formation of the LCR beam are seldom discussed. This paper reports a numerical model used to investigate the transducers' parameters that can contribute to the directionality of the LCR wave and hence enable performance optimization when used for industrial applications. An orthogonal test method is used to study the transducer parameters which influence the LCR wave beams. This method provides a design tool that can be used to study and optimize multiple parameter experiments and it can identify which parameter or parameters are of most significance. The simulation of the sound field in a 2-D "water-steel" model is obtained using a Spatial Fourier Analysis method. The effects of incident angle, standoff, the aperture and the center frequency of the transducer were studied. Results show that the aperture of the transducer, the center frequency and the incident angle are the most important factors in controlling the directivity of the resulting LCR wave fields.

  9. Analysis of critically refracted longitudinal waves

    SciTech Connect

    Pei, Ning Bond, Leonard J.

    2015-03-31

    Fabrication processes, such as, welding, forging, and rolling can induce residual stresses in metals that will impact product performance and phenomena such as cracking and corrosion. To better manage residual stress tools are needed to map their distribution. The critically refracted ultrasonic longitudinal (LCR) wave is one such approach that has been used for residual stress characterization. It has been shown to be sensitive to stress and less sensitive to the effects of the texture of the material. Although the LCR wave is increasingly widely applied, the factors that influence the formation of the LCR beam are seldom discussed. This paper reports a numerical model used to investigate the transducers' parameters that can contribute to the directionality of the LCR wave and hence enable performance optimization when used for industrial applications. An orthogonal test method is used to study the transducer parameters which influence the LCR wave beams. This method provides a design tool that can be used to study and optimize multiple parameter experiments and it can identify which parameter or parameters are of most significance. The simulation of the sound field in a 2-D 'water-steel' model is obtained using a Spatial Fourier Analysis method. The effects of incident angle, standoff, the aperture and the center frequency of the transducer were studied. Results show that the aperture of the transducer, the center frequency and the incident angle are the most important factors in controlling the directivity of the resulting LCR wave fields.

  10. Heat transfer in a longitudinal glow discharge

    NASA Astrophysics Data System (ADS)

    Yunusov, R. F.

    2017-01-01

    This article is devoted to the experimental study of heat transfer in a longitudinal glow discharge. The discharge was ignited in the discharge chamber (DC), consisting of a glass tube 10 mm in diameter and two electrodes. Copper electrodes were placed in the side branches, so that the average distance between them was 9 cm. The discharge pressure was varied in the range of P = (2.5 – 8.5) kPa. The air flow rate was varied from zero to G = 0.06 g / s. Current was varied in the range of I = (30-80) mA. Current-voltage characteristics of the discharge had falling form, and the voltage was varied in the range of U = (1-2) kV. The temperature of neutral particles in the plasma glow discharge was measured by six thermocouples, which were insertedon radius of DC. The aim of the article was to compare achieved experiment data with theoretical studies: recombination and diffusion plasma models.

  11. Semiparametric Bayesian classification with longitudinal markers

    PubMed Central

    De la Cruz-Mesía, Rolando; Quintana, Fernando A.; Müller, Peter

    2013-01-01

    Summary We analyse data from a study involving 173 pregnant women. The data are observed values of the β human chorionic gonadotropin hormone measured during the first 80 days of gestational age, including from one up to six longitudinal responses for each woman. The main objective in this study is to predict normal versus abnormal pregnancy outcomes from data that are available at the early stages of pregnancy. We achieve the desired classification with a semiparametric hierarchical model. Specifically, we consider a Dirichlet process mixture prior for the distribution of the random effects in each group. The unknown random-effects distributions are allowed to vary across groups but are made dependent by using a design vector to select different features of a single underlying random probability measure. The resulting model is an extension of the dependent Dirichlet process model, with an additional probability model for group classification. The model is shown to perform better than an alternative model which is based on independent Dirichlet processes for the groups. Relevant posterior distributions are summarized by using Markov chain Monte Carlo methods. PMID:24368871

  12. Longitudinal dynamics of a perching aircraft concept

    NASA Astrophysics Data System (ADS)

    Wickenheiser, Adam; Garcia, Ephrahim; Waszak, Martin

    2005-05-01

    This paper introduces a morphing aircraft concept whose purpose is to demonstrate a new bio-inspired flight capability: perching. Perching is a maneuver that utilizes primarily aerodynamics -- as opposed to thrust generation -- to achieve a vertical or short landing. The flight vehicle that will accomplish this is described herein with particular emphasis on its addition levels of actuation beyond the traditional aircraft control surfaces. A computer model of the aircraft is developed in order to predict the changes in applied aerodynamic loads as it morphs and transitions through different flight regimes. The analysis of this model is outlined, including a lifting-line-based analytical technique and a trim and stability analysis. These analytical methods -- compared to panel or computational fluid dynamics (CFD) methods -- are considered desirable for the analysis of a large number of vehicle configurations and flight conditions. The longitudinal dynamics of this aircraft are studied, and several interesting results are presented. Of special interest are the changes in vehicle dynamics as the aircraft morphs from a cruise configuration to initiate the perching maneuver. Changes in trim conditions and stability are examined as functions of vehicle geometry. The time response to changes in vehicle configuration is also presented.

  13. Longitudinal growth in chronic hypokalemic disorders.

    PubMed

    Gil-Peña, Helena; Mejia, Natalia; Alvarez-Garcia, Oscar; Loredo, Vanessa; Santos, Fernando

    2010-04-01

    Growth retardation remains a major complication in children with primary tubular disorders, despite adequate supplemental treatment with electrolytes, water and bicarbonate. Chronic hypokalemia, characteristic of some tubulopathies, impairs growth by mechanisms that are not well known. Association with growth hormone deficiency has been reported in patients with Bartter's or Gitelman's syndrome. Tissue-specific alterations of growth hormone and insulin-like growth factor I axis have been described in experimental models of potassium depletion. Hypokalemic rats gain less body length and weight than pair-fed normokalemic animals and, by contrast, develop renal hypertrophy. These rats have low circulating concentrations of insulin-like growth factor I, depressed messenger ribonucleic acid (mRNA) levels of this peptide in the tibial growth plate, and they are resistant to the longitudinal growth-promoting effects of exogenous growth hormone. The reason for this resistance remains to be defined. No alterations in the intracellular signaling for growth hormone have been found in the liver of hypokalemic rats. However, treatment with high doses of growth hormone is unable to normalize hypertrophy of the epiphyseal cartilage chondrocytes, which are severely disturbed in potassium depletion and likely play an important role in the pathogenia of growth impairment in this condition.

  14. Cuba's Aging and Alzheimer Longitudinal Study.

    PubMed

    Llibre-Rodríguez, Juan de Jesús; Valhuerdi-Cepero, Adolfo; López-Medina, Ana M; Noriega-Fernández, Lisseth; Porto-Álvarez, Rutbeskia; Guerra-Hernández, Milagros A; Bosch-Bayard, Rodolfo I; Zayas-Llerena, Tania; Hernandez-Ulloa, Elaine; Rodríguez-Blanco, Ana L; Salazar-Pérez, Enrique; Llibre-Guerra, Juan C; Llibre-Guerra, Jorge J; Marcheco-Teruel, Beatriz

    2017-01-01

    Aging and Alzheimer is a prospective, longitudinal cohort study involving 2944 adults aged ≥65 years from selected areas in Cuba's Havana and Matanzas Provinces. This door-to-door study, which began in 2003, includes periodic assessments of the cohort based on an interview; physical exam; anthropometric measurements; and diagnosis of dementia and its subtypes, other mental disorders, and other chronic non-communicable diseases and their risk factors. Information was gathered on sociodemographic characteristics; disability, dependency and frailty; use of health services; and characteristics of care and caregiver burden. The first assessment also included blood tests: complete blood count, blood glucose, kidney and liver function, lipid profile and ApoE4 genotype (a susceptibility marker). In 2007-2011, the second assessment was done of 2010 study subjects aged ≥65 years who were still alive. The study provides data on prevalence and incidence of dementia and its risk factors, and of related conditions that affect the health of older adults. It also contributes valuable experiences from field work and interactions with older adults and their families. Building on lessons learned, a third assessment to be done in 2016-2018 will incorporate a community intervention strategy to respond to diseases and conditions that predispose to dementia, frailty and dependency in older adults. KEYWORDS Dementia, Alzheimer disease, chronic disease, aging, chronic illness, frailty, dependency, cohort studies, Cuba.

  15. Personality and Smoking Status: A Longitudinal Analysis

    PubMed Central

    Munafó, Marcus R.; Black, Stephanie

    2007-01-01

    We attempted to clarify the strength and nature of the association between personality and smoking status in early and middle adulthood, using a longitudinal study design. Data from the Medical Research Council National Survey of Health and Development, based on a stratified sample of all single, legitimate births occurring in England, Wales, and Scotland in one week of March 1946 (N=5,362), were analyzed using generalized estimating equations methods to account for the correlation between the smoking status variables for the same individual over time. The unadjusted estimates indicated that the odds of being a current smoker increased with higher personality score for both extraversion (p<.0001) and neuroticism (p<.0001) traits. Sex was significantly associated with being a current smoker (p<.0001), with males more likely than females to be current smokers. Current smoking decreased with increasing age (p<.0001). These relationships were maintained in the fully adjusted model. These data indicate that both higher levels of extraversion and higher levels of neuroticism, as measured at age 16, are independently associated with an increased likelihood of subsequently being a current smoker rather than a nonsmoker at all time points, although the observed effect sizes were small. Males also were more likely than females to be current smokers, and increasing age reduced the likelihood of being a current smoker, which is consistent with an attempt by a subset of smokers in the cohort to subsequently stop smoking. PMID:17365771

  16. Longitudinal variability of black carbon vertical profiles

    NASA Astrophysics Data System (ADS)

    Schwarz, J. P.; Weinzierl, B.; Samset, B. H.; Perring, A. E.; Dollner, M.; Heimerl, K.; Markovic, M. Z.; Ziemba, L. D.

    2015-12-01

    Black carbon (BC) aerosol contributes substantially to both climate forcing and climate forcing uncertainty. An important source of this uncertainty derives from the difficulty in predicting BC's global abundance and vertical distribution. Here we present a multi-year record of black carbon (BC) vertical concentration profiles from both sides of the Atlantic, obtained from airborne Single Particle Soot Photometers (SP2s) flown on the NASA DC-8, and the DLR Falcon research aircraft from the CONCERT, ACCESS, DC3, SEAC4RS, and SALTRACE campaigns. The measurements constrain the relative rates of BC transport/removal from, and zonal mixing in, the upper troposphere, as well as the range of BC loadings in these regions. They also constrain the time-rates of change of BC loads in altitudes at which it is a highly efficient (although sparse) climate forcer, and a relatively long-lived aerosol tracer. We find that concentration of BC in the upper troposphere can vary by a factor 10. Over the Northern mid-latitudes concentrations are however consistent to a fraction of this range over wide longitudinal ranges, over month-long timescales. The data show that BC becomes zonally mixed here starting at 500 hPa and extending to near the tropopause. These results imply broader value than previously associated with measured vertical profiles in constraining global scale BC loadings aloft.

  17. Sortilin receptor 1 predicts longitudinal cognitive change.

    PubMed

    Reynolds, Chandra A; Zavala, Catalina; Gatz, Margaret; Vie, Loryana; Johansson, Boo; Malmberg, Bo; Ingelsson, Erik; Prince, Jonathan A; Pedersen, Nancy L

    2013-06-01

    The gene encoding sortilin receptor 1 (SORL1) has been associated with Alzheimer's disease risk. We examined 15 SORL1 variants and single nucleotide polymorphism (SNP) set risk scores in relation to longitudinal verbal, spatial, memory, and perceptual speed performance, testing for age trends and sex-specific effects. Altogether, 1609 individuals from 3 population-based Swedish twin studies were assessed up to 5 times across 16 years. Controlling for apolipoprotein E genotype (APOE), multiple simple and sex-moderated associations were observed for spatial, episodic memory, and verbal trajectories (p = 1.25E-03 to p = 4.83E-02). Five variants (rs11600875, rs753780, rs7105365, rs11820794, rs2070045) were associated across domains. Notably, in those homozygous for the rs2070045 risk allele, men demonstrated initially favorable performance but accelerating declines, and women showed overall lower performance. SNP set risk scores predicted spatial (Card Rotations, p = 5.92E-03) and episodic memory trajectories (Thurstone Picture Memory, p = 3.34E-02), where higher risk scores benefited men's versus women's performance up to age 75 but with accelerating declines. SORL1 is associated with cognitive aging, and might contribute differentially to change in men and women. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. Laser Wakefield diagnostic using holographic longitudinal interferometry

    SciTech Connect

    Volfbeyn, P.; Esarey, E.; Leemans, W.P.

    1999-03-26

    We propose a diagnostic technique for wakefield measurement in plasma channels. A new technique for plasma channel creation, the Ignitor Heater scheme was proposed and experimentally tested in hydrogen and nitrogen previously. It makes use of two laser pulses. The Ignitor, an ultrashort (sub 100 fs) laser pulse, is brought to a line focus using a cylindrical lens to ionize the gas. The Heater pulse (160 ps long) is used to heat the existing spark via in-verse Bremsstrahlung. The hydrodynamic shock expansion creates a partially evacuated plasma channel with a density minimum on axis. Such a channel has properties of an optical waveguide. This technique allows creation of plasma channels in low atomic number gases, such as hydrogen, which is of importance for guiding of highly intense laser pulses. Laser pulses injected into such plasma channels produce a plasma wake that has a phase velocity close to the speed of light. A discussion of plasma wake measurements, using a Longitudinal Interferometry Wakefield Diagnostic Based on Time Domain Rayleigh Refractometry with Holographic Inversion, will be presented.

  19. Longitudinal performance of an implantable vestibular prosthesis.

    PubMed

    Phillips, Christopher; Ling, Leo; Oxford, Trey; Nowack, Amy; Nie, Kaibao; Rubinstein, Jay T; Phillips, James O

    2015-04-01

    Loss of vestibular function may be treatable with an implantable vestibular prosthesis that stimulates semicircular canal afferents with biphasic pulse trains. Several studies have demonstrated short-term activation of the vestibulo-ocular reflex (VOR) with electrical stimulation. Fewer long-term studies have been restricted to small numbers of animals and stimulation designed to produce adaptive changes in the electrically elicited response. This study is the first large consecutive series of implanted rhesus macaque to be studied longitudinally using brief stimuli designed to limit adaptive changes in response, so that the efficacy of electrical activation can be studied over time, across surgeries, canals and animals. The implantation of a vestibular prosthesis in animals with intact vestibular end organs produces variable responses to electrical stimulation across canals and animals, which change in threshold for electrical activation of eye movements and in elicited slow phase velocities over time. These thresholds are consistently lower, and the slow phase velocities higher, than those obtained in human subjects. The changes do not appear to be correlated with changes in electrode impedance. The variability in response suggests that empirically derived transfer functions may be required to optimize the response of individual canals to a vestibular prosthesis, and that this function may need to be remapped over time. This article is part of a Special Issue entitled .

  20. Longitudinal quantile regression in the presence of informative dropout through longitudinal-survival joint modeling.

    PubMed

    Farcomeni, Alessio; Viviani, Sara

    2015-03-30

    We propose a joint model for a time-to-event outcome and a quantile of a continuous response repeatedly measured over time. The quantile and survival processes are associated via shared latent and manifest variables. Our joint model provides a flexible approach to handle informative dropout in quantile regression. A Monte Carlo expectation maximization strategy based on importance sampling is proposed, which is directly applicable under any distributional assumption for the longitudinal outcome and random effects. We consider both parametric and nonparametric assumptions for the baseline hazard. We illustrate through a simulation study and an application to an original data set about dilated cardiomyopathies.

  1. Medial Longitudinal Arch Development of Children Aged 7 to 9 Years: Longitudinal Investigation.

    PubMed

    Tong, Jasper W K; Kong, Pui W

    2016-08-01

    It is unclear at what age the medial longitudinal arch (MLA) of the foot becomes stable in children. The influence of footwear on MLA development also is unknown. The purpose of this study was to examine the MLA development of children using a longitudinal approach. The relationship between wearing different types of footwear and MLA development also was explored longitudinally. This was a longitudinal cohort observational study. The MLA of 111 healthy children (mean age=6.9 years, SD=0.3) was evaluated using 3 parameters (arch index [AI], midfoot peak pressure [PP], and maximum force [MF]) extracted from dynamic foot loading measurements at baseline (t0), 10-month follow-up (t1), and 22-month follow-up (t2). Information on footwear usage was surveyed. Linear mixed modeling was used to test for differences in MLA over time. The MLA of the children remained stable over time (AI: t0/t1/t2=0.25 [95% confidence interval (CI)=0.24, 0.26]/0.25 [95% CI=0.24, 0.26]/0.25 [95% CI=0.24, 0.26]; P=.95). When the children's sex was considered, the AI of boys decreased (higher arch) with age (0.26 [95% CI=0.24, 0.27]/0.25 [95% CI=0.24, 0.27]/0.25 [95% CI=0.23, 0.27]; P=.02). Boys also displayed a flatter MLA than girls at age 6.9 years (AI: mean difference=0.02 [95% CI=0.01, 0.04]; P=.02). At baseline, children who wore closed-toe shoes displayed the lowest MLA overall (AI: closed-toe shoes/sandals/slippers=0.26 [95% CI=0.24, 0.28]/0.24 [95% CI=0.23, 0.25]/0.25 [95% CI=0.24, 0.26]; P<.01). Children who used slippers at toddlers' age experienced a higher PP (flatter arch) in later childhood than those who wore sandals (mean difference=31.60 kPa [95% CI=1.44, 61.75]; post hoc P=.04). Information on the type of footwear worn was self-reported and, therefore, may be subjected to recall bias. The MLA of children remained stable from 7 to 9 years of age. The child's sex and the type of footwear worn during childhood may influence MLA development. © 2016 American Physical Therapy

  2. BOOK REVIEW: Geheimnisvolles Universum - Europas Astronomen entschleiern das Weltall

    NASA Astrophysics Data System (ADS)

    Duerbeck, H. W.; Lorenzen, D. H.

    2002-12-01

    The 25th birthday of ESO, in 1987, was celebrated by the publication of an illustrated popular book, "Exploring the Southern Sky" (Springer-Verlag 1987), which also saw editions in Danish, English, French, German, and Spanish. Written and illustrated by the ESO staff members Svend Laustsen, Claus Madsen and Richard M. West, its many pictures were mainly taken with the ESO 3.6m and Schmidt telescopes. The structure of the book - perhaps at that time somewhat unusual - started with things far away (Universe and galaxies), zoomed in to the Milky Way, and finally reached the Solar System (with a concluding chapter dealing with the La Silla observatory). Now, with the 4 units of the Very Large Telescope in full operation, and on the occasion of ESO's 40th birthday, another jubilee book has appeared: "Geheimnisvolles Universum: Europas Astronomen entschleiern das Weltall", written by the science journalist Dirk H. Lorenzen, of Hamburg, Germany, and prefaced by Catherine Cesarsky, Director General of ESO. Presumably, this book will also soon become available in more languages spoken in ESO member countries. Thus it may be worthwhile to review the first edition, although some readers may like to wait for more easily accessible editions. Before going into details, let me first mention that I find this a very impressing book, great to look at and refreshing to read. With ESO seen through the eyes of a visitor, things gain a perspective that is quite different from that of the previous book, and at least as attractive. It comes as no surprise that the book starts with a visit of ESO's showcase, the Paranal Observatory, and the writer not only notes down his own impressions, but also cites statements of some of the many people that keep Paranal going - technicians and staff astronomers. This mixture of texts provides a good impression of the operations at a large observatory for the general reader. The two more 'astronomical' parts that follow deal with star and planet

  3. Introduction to longitudinal data analysis in psychiatric research.

    PubMed

    Liu, Xian

    2015-08-25

    The onset, course, and management of mental health problems typically occur over relatively long periods of time, so a substantial proportion of psychiatric research - particularly the research that can provide clear answers about the complex interaction of biological, psychological, and social factors - requires multiple assessments of individuals and the environments in which they live over time. However, many psychiatric researchers use incorrect statistical methods to analyze this type of longitudinal data, a problem that can result in unrecognized bias in analytic results and, thus, incorrect conclusions. This paper provides an introduction to the topic of longitudinal data analysis. It discusses the different dataset structures used in the analysis of longitudinal data, the classification and management of missing data, and methods of adjusting for intra-individual correlation when developing multivariate regression models using longitudinal data.

  4. Longitudinal Stability of Person Characteristics: Intelligence and Creativity.

    ERIC Educational Resources Information Center

    Magnusson, D.; Backteman, G.

    1979-01-01

    A longitudinal study of approximately 1,000 students aged 10-16 showed high stability of intelligence and creativity. Stability coefficients for intelligence were higher than those for creativity. Results supported the construct validity of creativity. (MH)

  5. Coupling of transverse and longitudinal waves in piano strings.

    PubMed

    Etchenique, Nikki; Collin, Samantha R; Moore, Thomas R

    2015-04-01

    The existence of longitudinal waves in vibrating piano strings has been previously established, as has their importance in producing the characteristic sound of the piano. Modeling of the coupling between the transverse and longitudinal motion of strings indicates that the amplitude of the longitudinal waves are quadratically related to the transverse displacement of the string, however, experimental verification of this relationship is lacking. In the work reported here this relationship is tested by driving the transverse motion of a piano string at only two frequencies, which simplifies the task of unambiguously identifying the constituent signals. The results indicate that the generally accepted relationship between the transverse motion and the longitudinal motion is valid. It is further shown that this dependence on transverse displacement is a good approximation when a string is excited by the impact of the hammer during normal play.

  6. Room 106, A laboratory with longitudinal arrangement of benches. View ...

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

    Room 106, A laboratory with longitudinal arrangement of benches. View to west. - San Bernardino Valley College, Life Science Building, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  7. Interactive computer program for optimal designs of longitudinal cohort studies.

    PubMed

    Tekle, Fetene B; Tan, Frans E S; Berger, Martijn P F

    2009-05-01

    Many large scale longitudinal cohort studies have been carried out or are ongoing in different fields of science. Such studies need a careful planning to obtain the desired quality of results with the available resources. In the past, a number of researches have been performed on optimal designs for longitudinal studies. However, there was no computer program yet available to help researchers to plan their longitudinal cohort design in an optimal way. A new interactive computer program for the optimization of designs of longitudinal cohort studies is therefore presented. The computer program helps users to identify the optimal cohort design with an optimal number of repeated measurements per subject and an optimal allocations of time points within a given study period. Further, users can compute the loss in relative efficiencies of any other alternative design compared to the optimal one. The computer program is described and illustrated using a practical example.

  8. Multivariate longitudinal data analysis with mixed effects hidden Markov models.

    PubMed

    Raffa, Jesse D; Dubin, Joel A

    2015-09-01

    Multiple longitudinal responses are often collected as a means to capture relevant features of the true outcome of interest, which is often hidden and not directly measurable. We outline an approach which models these multivariate longitudinal responses as generated from a hidden disease process. We propose a class of models which uses a hidden Markov model with separate but correlated random effects between multiple longitudinal responses. This approach was motivated by a smoking cessation clinical trial, where a bivariate longitudinal response involving both a continuous and a binomial response was collected for each participant to monitor smoking behavior. A Bayesian method using Markov chain Monte Carlo is used. Comparison of separate univariate response models to the bivariate response models was undertaken. Our methods are demonstrated on the smoking cessation clinical trial dataset, and properties of our approach are examined through extensive simulation studies.

  9. Optical encryption in the longitudinal domain of focused fields.

    PubMed

    Carnicer, Artur; Juvells, Ignasi; Javidi, Bahram; Martínez-Herrero, Rosario

    2016-04-04

    We develop a method for encoding information in the longitudinal component of a focused field. Focused beams display a non-zero contribution of the electric field in the direction of propagation. However, the associated irradiance is very weak and difficult to isolate from the transverse part of the beam. For these reasons, the longitudinal component of a focused field could be a good choice for encoding and securing information. Using the Richards and Wolf formalism we show how to encrypt information in the longitudinal domain of the focal area. In addition, we use quantum imaging techniques to enhance the security and to prevent unauthorized access to the information. To the best of our knowledge, this is the first report on using the longitudinal component of the focused fields in optical security.

  10. 29. HAWSER DEVICE, DEVELOPED AT WES FOR MEASURING LONGITUDINAL AND ...

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

    29. HAWSER DEVICE, DEVELOPED AT WES FOR MEASURING LONGITUDINAL AND TRANSVERSE STRESS OF BARGES IN CANAL LOCKS. - Waterways Experiment Station, Hydraulics Laboratory, Halls Ferry Road, 2 miles south of I-20, Vicksburg, Warren County, MS

  11. A NEW METHOD OF LONGITUDINAL DIARY ASSEMBLY FOR EXPOSURE MODELING

    EPA Science Inventory

    Many stochastic human exposure models require the construction of longitudinal time-activity diaries to evaluate the time sequence of concentrations encountered, and hence, the pollutant exposure for the simulated individuals. However, most of the available data on human activiti...

  12. New design of longitudinal ultrasonic vibrator for wire drawing

    NASA Astrophysics Data System (ADS)

    Yang, Yuancai; Yuan, Jiangbo; Liu, Shen; Shan, Xiaobiao

    2017-04-01

    This paper presents a quarter-wave longitudinal vibrator which is applied to ultrasonic assisted wire drawing. The characteristic of this vibrator is only driven by an axially polarized sandwich PZT stack, which converts electrical energy into mechanical vibration energy. The transducer and horn were designed at the same side of the nodal section to achieve greater vibration at the front of the horn. The four-terminal network method was used to design the vibrator. The finite element method (FEM) was adopted to verify the above design and used for the further analysis about the vibration performances of this vibrator. The numberial caculation results match well with the simulation results. The simulation indicates that the resonance frequency of the longitudinal vibration is about 19.6188 kHz and the amplitude of longitudinal vibration at the end of the horn is about 11.48 μm. The present work provides a new longitudinal vibrator for ultrasonic wire drawing.

  13. 8. ENGINE TEST CELL BUILDING INTERIOR. LONGITUDINAL CENTRAL PASSAGEWAY IN ...

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

    8. ENGINE TEST CELL BUILDING INTERIOR. LONGITUDINAL CENTRAL PASSAGEWAY IN BASEMENT. LOOKING SOUTHWEST. - Fairchild Air Force Base, Engine Test Cell Building, Near intersection of Arnold Street & George Avenue, Spokane, Spokane County, WA

  14. 3. VIEW, LOOKING SOUTHEAST, SHOWING WEST LONGITUDINAL ELEVATION OF NORTH ...

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

    3. VIEW, LOOKING SOUTHEAST, SHOWING WEST LONGITUDINAL ELEVATION OF NORTH END SPAN - East Bloomsburg Bridge, Spanning Susquehanna River at Pennsylvania Route 487 (Legislative Route 283), Bloomsburg, Columbia County, PA

  15. 1. VIEW, LOOKING SOUTHWEST, SHOWING EAST LONGITUDINAL ELEVATION OF FULL ...

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

    1. VIEW, LOOKING SOUTHWEST, SHOWING EAST LONGITUDINAL ELEVATION OF FULL SIX SPANS - East Bloomsburg Bridge, Spanning Susquehanna River at Pennsylvania Route 487 (Legislative Route 283), Bloomsburg, Columbia County, PA

  16. 2. VIEW, LOOKING SOUTHEAST, SHOWING WEST LONGITUDINAL ELEVATION OF FULL ...

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

    2. VIEW, LOOKING SOUTHEAST, SHOWING WEST LONGITUDINAL ELEVATION OF FULL SIX SPANS - East Bloomsburg Bridge, Spanning Susquehanna River at Pennsylvania Route 487 (Legislative Route 283), Bloomsburg, Columbia County, PA

  17. J's Rhymes: A Longitudinal Case Study of Language Play.

    ERIC Educational Resources Information Center

    Inkelas, Sharon

    2003-01-01

    A longitudinal study of one children documents an invented language game consisting of suffixal reduplication and onset replacement. Argues that this game may more closely resemble adult rhyme. (Author/VWL)

  18. Introduction to collective instabilities----longitudinal and transverse

    SciTech Connect

    King-Yuen Ng

    1998-10-01

    These topics are covered: 1 Wakes and impedances 1.1 Wake functions 1.2 Coupling impedances 2 Longitudinal phase space 2.1 Equations of motion 2.2 Vlasov equation 3 Potential-well distortion 4 Longitudinal microwave instability 4.1 Dispersion relation 4.2 Landau damping 4.3 Self-bunching 4.4 Overshoot and bunch lengthening 4.5 Observation 5 Longitudinal coupled-bunch instabilities 5.1 Sacherer integral equation 5.2 Time domain 5.3 Rf-detuning and Robinson's stability criteria 6 Transverse instabilities 6.1 Sacherer integral equation 6.2 Solution of Sacherer integral equations 6.1 Sacherer sinusoidal modes of excitation 6.2 Chromaticity frequency shift 7 Transverse coupled-bunch instabilities 7.1 Resistive wall 7.2 Narrow resonances 8 Head-tail instabilities 9 Mode-mixing 9.1 Transverse 9.2 Longitudinal. Exercises are included.

  19. A NEW METHOD OF LONGITUDINAL DIARY ASSEMBLY FOR EXPOSURE MODELING

    EPA Science Inventory

    Many stochastic human exposure models require the construction of longitudinal time-activity diaries to evaluate the time sequence of concentrations encountered, and hence, the pollutant exposure for the simulated individuals. However, most of the available data on human activiti...

  20. Photocopy of longitudinal, cross sections and roof plan of the ...

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

    Photocopy of longitudinal, cross sections and roof plan of the C.B. & Q. R.R. roundhouse and locomotive shops. June 1980. - Chicago, Burlington & Quincy Railroad, Roundhouse & Shops, Broadway & Spring Streets, Aurora, Kane County, IL

  1. Viability of longitudinal trenches for capturing contaminated groundwater.

    PubMed

    Hudak, Paul F

    2010-04-01

    Using a groundwater flow and mass transport model, this study compared the capability of trenches with permeable backfill for capturing hypothetical contaminant plumes in homogeneous and heterogeneous unconfined aquifers. Longitudinal (parallel to groundwater flow), as well as conventional transverse (perpendicular to groundwater flow) trench configurations were considered. Alternate trench configurations intercepted the leading tip of an initial contaminant plume and had identical length, equal to the cross-gradient width of the plume. A longitudinal trench required 31% less time than its transverse counterpart to remediate a homogeneous aquifer. By contrast, in simulated heterogeneous aquifers, longitudinal remediation timeframes ranged from 41% less to 33% more than transverse trenches. Results suggest that longitudinal trenches may be a viable alternative for narrow contaminant plumes under low-groundwater velocity conditions, but may be impractical for plumes with wide leading tips, or in complex heterogeneous aquifers with divergent flow.

  2. Longitudinal Beam Diagnostics for the ILC Injectors and Bunch Compressors

    SciTech Connect

    Piot, Philippe; Bracke, Adam; Demir, Veysel; Maxwell, Timothy; Rihaoui, Marwan; Jing, Chunguang; Power, John

    2010-12-01

    We present a diagnostics suite and analyze techniques for setting up the longitudinal beam dynamics in ILC e⁻ injectors and e⁺ and e⁻ bunch compressors. Techniques to measure the first order moments and recover the first order longitudinal transfer map of the injector's intricate bunching scheme are presented. Coherent transition radiation diagnostics needed to measure and monitor the bunch length downstream of the ~5 GeV bunch compressor are investigated using a vector diffraction model.

  3. Simultaneous maximum a posteriori longitudinal PET image reconstruction

    NASA Astrophysics Data System (ADS)

    Ellis, Sam; Reader, Andrew J.

    2017-09-01

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

  4. Definition and application of longitudinal stability derivatives for elastic airplanes

    NASA Technical Reports Server (NTRS)

    Kemp, W. B., Jr.

    1972-01-01

    A set of longitudinal stability derivatives for elastic airplanes is defined from fundamental principles allowing perturbations in forward speed. Application of these derivatives to longitudinal stability analysis by use of approximate expressions for static stability and control parameters as well as the dynamic equations of motion is illustrated. One commonly used alternative formulation for elastic airplanes is shown to yield significant inaccuracies because of inappropriate interpretation of inertial effects.

  5. Longitudinal incision in surgical release of De Quervain disease.

    PubMed

    Gundes, Hakan; Tosun, Bilgehan

    2005-09-01

    The objective of this paper is to contrast the use of a longitudinal incision in surgical decompression of De Quervain disease with a transverse incision. The advantages are ease in recognition of compartment variations and superficial branches of radial nerve and prevention of palmar tendon subluxation by permitting a more dorsal release of the compartment sheath. Since 2002, we have used a longitudinal skin incision instead of the classic transverse incision to release the first dorsal compartment.

  6. Longitudinal dispersion modeling in small streams

    NASA Astrophysics Data System (ADS)

    Pekarova, Pavla; Pekar, Jan; Miklanek, Pavol

    2014-05-01

    The environmental problems caused by the increasing of pollutant loads discharged into natural water bodies are very complex. For that reason the cognition of transport mechanism and mixing characteristics in natural streams is very important. The mathematical and numerical models have become very useful tools for solving the water management problems. The mathematical simulations based on numerical models of pollution mixing in streams can be used (for example) for prediction of spreading of accidental contaminant waves in rivers. The paper deals with the estimation of the longitudinal dispersion coefficients and with the numerical simulation of transport and transformation of accidental pollution in the small natural streams. There are different ways of solving problems of pollution spreading in open channels, in natural rivers. One of them is the hydrodynamic approach, which endeavours to understand and quantify the spreading phenomenon in a stream. The hydrodynamic models are based on advection-diffusion equation and the majority of them are one-dimensional models. Their disadvantage is inability to simulate the spread of pollution until complete dispersion of pollutant across the stream section is finished. Two-dimensional mixing models do not suffer from these limitations. On the other hand, the one-dimensional models are simpler than two-dimensional ones, they need not so much input data and they are often swifter. Three-dimensional models under conditions of natural streams are applicable with difficulties (or inapplicable) for their complexity and demands on accuracy and amount of input data. As there was mentioned above the two-dimensional models can be used also until complete dispersion of pollutant across the stream section is not finished, so we decided to apply the two-dimensional model SIRENIE. Experimental microbasin Rybarik is the part of the experimental Mostenik brook basin of IH SAS Bratislava. It was established as a Field Hydrological

  7. Traveltime and longitudinal dispersion in Illinois streams

    USGS Publications Warehouse

    Graf, Julia B.

    1986-01-01

    Twenty-seven measurements of traveltime and longitudinal dispersion in 10 Illinois streams made from 1975 to 1982 provide data needed for estimating traveltime of peak concentration of a conservative solute, traveltime of the leading edge of a solute cloud, peak concentration resulting from injection of a given quantity of solute, and passage time of solute past a given point on a stream. These four variables can be estimated graphically for each stream from distance of travel and either discharge at the downstream end of the reach or flow-duration frequency. From equations developed from field measurements, the traveltime and dispersion characteristics also can be estimated for other unregulated streams in Illinois that have drainage areas less than about 1,500 square miles. For unmeasured streams, traveltime of peak concentration and of the leading edge of the cloud are related to discharge at the downstream end of the reach and to distance of travel. For both measured and unmeasured streams, peak concentration and passage time are best estimated from the relation of each to traveltime. In measured streams, dispersion efficiency is greater than that predicted by Fickian diffusion theory. The rate of decrease in peak concentration with traveltime is about equal to the rate of increase in passage time. Average velocity in a stream reach, given by the velocity of the center of solute mass in that reach, can be estimated from an equation developed from measured values. The equation relates average reach velocity to discharge at the downstream end of the reach. Average reach velocities computed for 9 of the 10 streams from available equations that are based on hydraulic-geometry relations are high relative to measured values. The estimating equation developed from measured velocities provides estimates of average reach velocity that are closer to measured velocities than are those computed using equations developed from hydraulic-geometry relations.

  8. Longitudinal Association of Dementia and Depression

    PubMed Central

    Snowden, Mark B.; Atkins, David C.; Steinman, Lesley E.; Bell, Janice F.; Bryant, Lucinda L.; Copeland, Catherine; Fitzpatrick, Annette L.

    2015-01-01

    Objectives Depression is an important precursor to dementia, but less is known about the role dementia plays in altering the course of depression. We examined whether depression prevalence, incidence, and severity are higher in those with dementia versus those with mild cognitive impairment (MCI), or normal cognition. Design Prospective cohort study using the longitudinal Uniform Data Set of the National Alzheimer's Coordinating Center (2005–2013). Setting 34 Alzheimer Disease research centers. Participants 27,776 subjects with dementia, MCI, or normal cognition. Measurements Depression status was determined by a clinical diagnosis of depression within the prior 2 years and by a Geriatric Depression Scale-Short Form score >5. Results Rates of depression were significantly higher in subjects with MCI and dementia compared with those with normal cognition at index visit. Controlling for demographics and common chronic conditions, logistic regression analysis revealed elevated depression in those with MCI (OR: 2.40 [95% CI: 2.25, 2.56]) or dementia (OR: 2.64 [95% CI: 2.43, 2.86]) relative to those with normal cognition. In the subjects without depression at the index visit (N = 18,842), those with MCI and dementia had higher probabilities of depression diagnosis 2 years post index visit than those with normal cognition: MCI = 21.7%, dementia 24.7%, normal cognition = 10.5%. Conclusion MCI and dementia were associated with significantly higher rates of depression in concurrent as well as prospective analyses. These findings suggest that efforts to effectively engage and treat older adults with dementia will need also to address co-occurring depression. PMID:25441056

  9. Longitudinal Association of Dementia and Depression.

    PubMed

    Snowden, Mark B; Atkins, David C; Steinman, Lesley E; Bell, Janice F; Bryant, Lucinda L; Copeland, Catherine; Fitzpatrick, Annette L

    2015-09-01

    Depression is an important precursor to dementia, but less is known about the role dementia plays in altering the course of depression. We examined whether depression prevalence, incidence, and severity are higher in those with dementia versus those with mild cognitive impairment (MCI), or normal cognition. Prospective cohort study using the longitudinal Uniform Data Set of the National Alzheimer's Coordinating Center (2005-2013). 34 Alzheimer Disease research centers. 27,776 subjects with dementia, MCI, or normal cognition. Depression status was determined by a clinical diagnosis of depression within the prior 2 years and by a Geriatric Depression Scale-Short Form score >5. Rates of depression were significantly higher in subjects with MCI and dementia compared with those with normal cognition at index visit. Controlling for demographics and common chronic conditions, logistic regression analysis revealed elevated depression in those with MCI (OR: 2.40 [95% CI: 2.25, 2.56]) or dementia (OR: 2.64 [95% CI: 2.43, 2.86]) relative to those with normal cognition. In the subjects without depression at the index visit (N = 18,842), those with MCI and dementia had higher probabilities of depression diagnosis 2 years post index visit than those with normal cognition: MCI = 21.7%, dementia = 24.7%, normal cognition = 10.5%. MCI and dementia were associated with significantly higher rates of depression in concurrent as well as prospective analyses. These findings suggest that efforts to effectively engage and treat older adults with dementia will need also to address co-occurring depression. Copyright © 2015 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.

  10. Longitudinal associations between reading and mathematics achievement.

    PubMed

    Grimm, Kevin J

    2008-01-01

    The association between early reading skills and changes in mathematics was examined in a large, low-income sample to determine whether students who have a greater level of reading skills in early elementary school exhibit more rapid gains in tests of mathematics. The longitudinal associations between third grade reading comprehension and changes in three components of mathematics achievement (Problem Solving and Data Interpretation, Mathematical Concepts and Estimation, Mathematical Computation) from third through eighth grade were examined. Latent growth models were fit to the repeated assessments of each mathematics component and the students' third grade reading and global mathematics scores were included as predictors of the intercept and slope. Gender, poverty status, and ethnicity were included in the models as control variables. The results showed males and African-American students tended to have shallower rates of change than females and non-African-American/non-Hispanic students. In terms of the effect of reading on changes in mathematics, third grade reading comprehension was found to be a positive significant predictor of change for each component of mathematics, suggesting students with a greater level of reading achievement in early elementary school change more rapidly in mathematics skills controlling for prior mathematics skills and student characteristics. The largest effects were shown for the Problem Solving and Data Interpretation test, a test focused on the applications of mathematics knowledge, and the Mathematical Concepts and Estimation test. Negligible effects were found for changes in Mathematical Computation. Thus, early reading comprehension was shown to be related to a conceptual understanding of mathematics and the application of mathematics knowledge. These findings lend support for the notion that early reading skills are important for success in mathematics.

  11. Longitudinal Diffusion Tensor Imaging in Frontotemporal Dementia

    PubMed Central

    Mahoney, Colin J; Simpson, Ivor J A; Nicholas, Jennifer M; Fletcher, Phillip D; Downey, Laura E; Golden, Hannah L; Clark, Camilla N; Schmitz, Nicole; Rohrer, Jonathan D; Schott, Jonathan M; Zhang, Hui; Ourselin, Sebastian; Warren, Jason D; Fox, Nick C

    2015-01-01

    Objective Novel biomarkers for monitoring progression in neurodegenerative conditions are needed. Measurement of microstructural changes in white matter (WM) using diffusion tensor imaging (DTI) may be a useful outcome measure. Here we report trajectories of WM change using serial DTI in a cohort with behavioral variant frontotemporal dementia (bvFTD). Methods Twenty-three patients with bvFTD (12 having genetic mutations), and 18 age-matched control participants were assessed using DTI and neuropsychological batteries at baseline and ∼1.3 years later. Baseline and follow-up DTI scans were registered using a groupwise approach. Annualized rates of change for DTI metrics, neuropsychological measures, and whole brain volume were calculated. DTI metric performances were compared, and sample sizes for potential clinical trials were calculated. Results In the bvFTD group as a whole, rates of change in fractional anisotropy (FA) and mean diffusivity (MD) within the right paracallosal cingulum were greatest (FA: −6.8%/yr, p < 0.001; MD: 2.9%/yr, p = 0.01). MAPT carriers had the greatest change within left uncinate fasciculus (FA: −7.9%/yr, p < 0.001; MD: 10.9%/yr, p < 0.001); sporadic bvFTD and C9ORF72 carriers had the greatest change within right paracallosal cingulum (sporadic bvFTD, FA: −6.7%/yr, p < 0.001; MD: 3.8%/yr, p = 0.001; C9ORF72, FA: −6.8%/yr, p = 0.004). Sample size estimates using FA change were substantially lower than neuropsychological or whole brain measures of change. Interpretation Serial DTI scans may be useful for measuring disease progression in bvFTD, with particular trajectories of WM damage emerging. Sample size calculations suggest that longitudinal DTI may be a useful biomarker in future clinical trials. PMID:25363208

  12. Longitudinal respiratory studies in older people

    PubMed Central

    Milne, J S

    1978-01-01

    Milne, J S (1978).Thorax, 33, 547-554. Longitudinal respiratory studies in older people. A random sample of older people in Edinburgh (215 men, 272 women aged 62-90 years) was examined with the MRC questionnaire on respiratory symptoms. The FEV1 and FVC were recorded. Spirograms were repeated after one and five years and the questions after five years, the sample by then having been reduced to 133 men and 148 women. After five years 7% of the surviving men and women had developed persistent cough and phlegm. This syndrome had disappeared in 12% of men and 2% of women. Dyspnoea had increased beyond grade 2 in 13% of men and 7% of women and had lessened only in 6% of women. One-quarter of male and one-seventh of female cigarette smokers had given up smoking, mostly in the first year. Nearly all who stopped were symptomless before and after. In those men who stopped smoking before the study began symptom prevalence was similar to that in those who continued smoking. Mean values of FEV1 and FVC declined as age increased, the decline being greater in FVC with resulting rise in FEV1%. Five-year differences in FEV1 and FVC were symmetrically distributed with mean differences increasing with age. Mean differences in FEV1 were 280-350 ml in men and 150-230 ml in women. Prediction equations from the first examinations remained usable for clinical work. Mean values of FEV1 and FVC at the first examination were smaller in those who died compared with survivors, whether symptoms were present or not. The prevalence of symptoms was greater in those who died. PMID:725823

  13. Longitudinal changes in white matter microstructure after heavy cannabis use

    PubMed Central

    Becker, Mary P.; Collins, Paul F.; Lim, Kelvin O.; Muetzel, R.L.; Luciana, M.

    2015-01-01

    Diffusion tensor imaging (DTI) studies of cannabis users report alterations in brain white matter microstructure, primarily based on cross-sectional research, and etiology of the alterations remains unclear. We report findings from longitudinal voxelwise analyses of DTI data collected at baseline and at a 2-year follow-up on 23 young adult (18-20 years old at baseline) regular cannabis users and 23 age-, sex-, and IQ-matched non-using controls with limited substance use histories. Onset of cannabis use was prior to age 17. Cannabis users displayed reduced longitudinal growth in fractional anisotropy in the central and parietal regions of the right and left superior longitudinal fasciculus, in white matter adjacent to the left superior frontal gyrus, in the left corticospinal tract, and in the right anterior thalamic radiation lateral to the genu of the corpus callosum, along with less longitudinal reduction of radial diffusion in the right central/posterior superior longitudinal fasciculus, corticospinal tract, and posterior cingulum. Greater amounts of cannabis use were correlated with reduced longitudinal growth in FA as was relatively impaired performance on a measure of verbal learning. These findings suggest that continued heavy cannabis use during adolescence and young adulthood alters ongoing development of white matter microstructure, contributing to functional impairment. PMID:26602958

  14. Longitudinal changes in white matter microstructure after heavy cannabis use.

    PubMed

    Becker, Mary P; Collins, Paul F; Lim, Kelvin O; Muetzel, R L; Luciana, M

    2015-12-01

    Diffusion tensor imaging (DTI) studies of cannabis users report alterations in brain white matter microstructure, primarily based on cross-sectional research, and etiology of the alterations remains unclear. We report findings from longitudinal voxelwise analyses of DTI data collected at baseline and at a 2-year follow-up on 23 young adult (18-20 years old at baseline) regular cannabis users and 23 age-, sex-, and IQ-matched non-using controls with limited substance use histories. Onset of cannabis use was prior to age 17. Cannabis users displayed reduced longitudinal growth in fractional anisotropy in the central and parietal regions of the right and left superior longitudinal fasciculus, in white matter adjacent to the left superior frontal gyrus, in the left corticospinal tract, and in the right anterior thalamic radiation lateral to the genu of the corpus callosum, along with less longitudinal reduction of radial diffusion in the right central/posterior superior longitudinal fasciculus, corticospinal tract, and posterior cingulum. Greater amounts of cannabis use were correlated with reduced longitudinal growth in FA as was relatively impaired performance on a measure of verbal learning. These findings suggest that continued heavy cannabis use during adolescence and young adulthood alters ongoing development of white matter microstructure, contributing to functional impairment.

  15. Modeling Longitudinal Data Containing Non-Normal Within Subject Errors

    NASA Technical Reports Server (NTRS)

    Feiveson, Alan; Glenn, Nancy L.

    2013-01-01

    The mission of the National Aeronautics and Space Administration’s (NASA) human research program is to advance safe human spaceflight. This involves conducting experiments, collecting data, and analyzing data. The data are longitudinal and result from a relatively few number of subjects; typically 10 – 20. A longitudinal study refers to an investigation where participant outcomes and possibly treatments are collected at multiple follow-up times. Standard statistical designs such as mean regression with random effects and mixed–effects regression are inadequate for such data because the population is typically not approximately normally distributed. Hence, more advanced data analysis methods are necessary. This research focuses on four such methods for longitudinal data analysis: the recently proposed linear quantile mixed models (lqmm) by Geraci and Bottai (2013), quantile regression, multilevel mixed–effects linear regression, and robust regression. This research also provides computational algorithms for longitudinal data that scientists can directly use for human spaceflight and other longitudinal data applications, then presents statistical evidence that verifies which method is best for specific situations. This advances the study of longitudinal data in a broad range of applications including applications in the sciences, technology, engineering and mathematics fields.

  16. Longitudinal fluctuations in the Berezinskii-Kosterlitz-Thouless phase

    NASA Astrophysics Data System (ADS)

    Jakubczyk, Pawel; Metzner, Walter

    2017-02-01

    We analyze the interplay of longitudinal and transverse thermal fluctuations in a U(1 ) symmetric two-dimensional ϕ4 theory. Toward this end, we derive coupled renormalization-group equations for both types of fluctuations obtained from a linear (Cartesian) decomposition of the order-parameter field. Discarding the longitudinal fluctuations, the expected Berezinskii-Kosterlitz-Thouless phase characterized by a finite stiffness and an algebraic decay of order-parameter correlations is recovered. Renormalized by transverse fluctuations, the longitudinal mass scales to zero so that longitudinal fluctuations become increasingly important for small momenta. Within our expansion of the effective action, they generate a logarithmic decrease of the stiffness, in agreement with previous functional renormalization-group calculations. The logarithmic terms imply a deviation from the vanishing β function for the stiffness in the nonlinear σ model describing the phase fluctuations at three-loop order. To gain further insight, we also compute the flow of the parameters characterizing longitudinal and transverse fluctuations from a density-phase representation of the order-parameter field, with a cutoff on phase fluctuations. The power-law flow of the longitudinal mass and other quantities is thereby confirmed, but the stiffness remains finite in this approach. We conclude that the marginal flow of the stiffness obtained in the Cartesian representation is an artifact of the truncated expansion of momentum dependences.

  17. Joint Analysis of Survival Time and Longitudinal Categorical Outcomes

    PubMed Central

    Choi, Jaeun; Cai, Jianwen; Zeng, Donglin; Olshan, Andrew F.

    2013-01-01

    In biomedical or public health research, it is common for both survival time and longitudinal categorical outcomes to be collected for a subject, along with the subject’s characteristics or risk factors. Investigators are often interested in finding important variables for predicting both survival time and longitudinal outcomes which could be correlated within the same subject. Existing approaches for such joint analyses deal with continuous longitudinal outcomes. New statistical methods need to be developed for categorical longitudinal outcomes. We propose to simultaneously model the survival time with a stratified Cox proportional hazards model and the longitudinal categorical outcomes with a generalized linear mixed model. Random effects are introduced to account for the dependence between survival time and longitudinal outcomes due to unobserved factors. The Expectation-Maximization (EM) algorithm is used to derive the point estimates for the model parameters, and the observed information matrix is adopted to estimate their asymptotic variances. Asymptotic properties for our proposed maximum likelihood estimators are established using the theory of empirical processes. The method is demonstrated to perform well in finite samples via simulation studies. We illustrate our approach with data from the Carolina Head and Neck Cancer Study (CHANCE) and compare the results based on our simultaneous analysis and the separately conducted analyses using the generalized linear mixed model and the Cox proportional hazards model. Our proposed method identifies more predictors than by separate analyses. PMID:26052353

  18. Global Gridded Data from the Goddard Earth Observing System Data Assimilation System (GEOS-DAS)

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The Goddard Earth Observing System Data Assimilation System (GEOS-DAS) timeseries is a globally gridded atmospheric data set for use in climate research. This near real-time data set is produced by the Data Assimilation Office (DAO) at the NASA Goddard Space Flight Center in direct support of the operational EOS instrument product generation from the Terra (12/1999 launch), Aqua (05/2002 launch) and Aura (01/2004 launch) spacecrafts. The data is archived in the EOS Core System (ECS) at the Goddard Earth Sciences Data and Information Services Center/Distributed Active Archive Center (GES DISC DAAC). The data is only a selection of the products available from the GEOS-DAS. The data is organized chronologically in timeseries format to facilitate the computation of statistics. GEOS-DAS data will be available for the time period January 1, 2000, through present.

  19. Amerikas Einschätzung der deutschen Atomforschung: Das deutsche Uranprojekt

    NASA Astrophysics Data System (ADS)

    Walker, Mark

    2002-07-01

    Die amerikanischen Wissenschaftler und ihre emigrierten Kollegen, die am Bau der Atombombe beteiligt waren, verfügten über sehr widersprüchliche und großteils falsche Informationen über den Fortschritt des deutschen Uranprogramms. Noch nach Kriegsende lässt sich dies an Aussagen des Leiters der amerikanischen Alsos-Mission, Samuel Goudsmit, festmachen. Tatsächlich war das deutsche Programm hinsichtlich seiner wissenschaftlichen Grundlagen und des Managements nicht so unterlegen, wie vielfach behauptet wurde. Aber die deutschen Behörden waren nicht in der Lage, Geld und Ressourcen in gleichem Maße in das Uranprojekt zu investieren, wie etwa in das Peenemünder Raketenprojekt.

  20. DasR is a pleiotropic regulator required for antibiotic production, pigment biosynthesis, and morphological development in Saccharopolyspora erythraea.

    PubMed

    Liao, Cheng-Heng; Xu, Ya; Rigali, Sébastien; Ye, Bang-Ce

    2015-12-01

    The GntR-family transcription regulator, DasR, was previously identified as pleiotropic, controlling the primary amino sugar N-acetylglucosamine (GlcNAc) and chitin metabolism in Saccharopolyspora erythraea and Streptomyces coelicolor. Due to the remarkable regulatory impact of DasR on antibiotic production and development in the model strain of S. coelicolor, we here identified and characterized the role of DasR to secondary metabolite production and morphological development in industrial erythromycin-producing S. erythraea. The physiological studies have shown that a constructed deletion of dasR in S. erythraea resulted in antibiotic, pigment, and aerial hyphae production deficit in a nutrient-rich condition. DNA microarray assay, combined with quantitative real-time reverse transcription PCR (qRT-PCR), confirmed these results by showing the downregulation of the genes relating to secondary metabolite production in the dasR null mutant. Notably, electrophoretic mobility shift assays (EMSA) showed DasR as being the first identified regulator that directly regulates the pigment biosynthesis rpp gene cluster. In addition, further studies indicated that GlcNAc, the major nutrient signal of DasR-responsed regulation, blocked secondary metabolite production and morphological development. The effects of GlcNAc were shown to be caused by DasR mediation. These findings demonstrated that DasR is an important pleiotropic regulator for both secondary metabolism and morphological development in S. erythraea, providing new insights for the genetic engineering of S. erythraea with increased erythromycin production.

  1. Psychometric properties of the Death Anxiety Scale (DAS) among terminally ill cancer patients.

    PubMed

    Royal, Kenneth D; Elahi, Fereshte

    2011-01-01

    Research conducted with the terminally ill population in relation to death anxiety is rare and mostly outdated. The purpose of this study was to evaluate the psychometric properties of the widely used Death Anxiety Scale (DAS) on a sample of terminal cancer patients.Additionally, validation studies of the DAS have exclusively used traditional statistical methods for analysis. The current study utilized an item response theory technique (IRT), namely the Rasch Rating Scale model for data analysis. The methodology employed may be useful for other researchers conducting validation studies from an IRT perspective.

  2. PoroTomo: Map of DAS, Nodal, Vibroseis and Reftek Station Deployment

    SciTech Connect

    Kurt Feigl

    2016-10-15

    Map of DAS, nodal, vibroseis and Reftek stations during March 2016 deployment. The plot on the left has nodal stations labeled; the plot on the right has vibroseis observations labeled. Stations are shown in map-view using Brady's rotated X-Y coordinates with side plots denoting elevation with respect to the WGS84 ellipsoid. Blue circles denote vibroseis data, x symbols denote DAS (cyan for horizontal and magenta for vertical), black asterisks denote Reftek data, and red plus signs denote nodal data. This map can be found on UW-Madison's askja server at /PoroTomo/DATA/MAPS/Deployment_Stations.pdf

  3. The Deaf Acculturation Scale (DAS): Development and Validation of a 58-Item Measure

    PubMed Central

    Maxwell-McCaw, Deborah; Zea, Maria Cecilia

    2011-01-01

    This study involved the development and validation of the Deaf Acculturation Scale (DAS), a new measure of cultural identity for Deaf and hard-of-hearing (hh) populations. Data for this study were collected online and involved a nation-wide sample of 3,070 deaf/hh individuals. Results indicated strong internal reliabilities for all the subscales, and construct validity was established by demonstrating that the DAS could discriminate groups based on parental hearing status, school background, and use of self-labels. Construct validity was further demonstrated through factorial analyses, and findings resulted in a final 58-item measure. Directions for future research are discussed. PMID:21263041

  4. Das Lob der Sternkunst. Astronomie in der deutschen Aufklärung.

    NASA Astrophysics Data System (ADS)

    Baasner, R.

    Contents: 1. Einleitung. 2. Die Astronomie im Rahmen der Aufklärungs-Physik. 3. Das Lob der Sternkunst. 4. Ein Blick auf die Sternwarten. 5. Allgemeine Darstellungen der Sternkunde. 6. Schleppende Rezeption: Das kopernikanische Weltbild. 7. Himmelsphysik: Die Debatte um die causa gravitatis. 8. Theorie der Himmelskörper. 9. Die Erde als Gegenstand der Astronomie. 10. Die Sonne. 11. Der Mond. 12. Die Planeten. 13. Die Kometen. 14. Die Fixsterne. 15. Die Entstehung der Welt. 16. Beiträge der Astrotheologie. 17. Der Kampf gegen die Astrologen.

  5. An exploratory analysis of the factor structure of the Dysfunctional Attitude Scale-Form A (DAS).

    PubMed

    Moore, Michael T; Fresco, David M; Segal, Zindel V; Brown, Timothy A

    2014-10-01

    A number of studies have attempted to identify the factor structure of the Dysfunctional Attitude Scale (DAS). However, no studies have done so using a clinical sample of outpatients likely to generalize to the clinical trials in which the DAS is commonly used. The current investigation utilized exploratory structural equation modeling in an outpatient sample (N = 982) and found support for a one-factor solution (composed of 19 items). This solution was largely confirmed in a second outpatient sample (N = 301). Construct validity was demonstrated in correlations with measures of depression, social interaction anxiety, and symptoms of obsessive-compulsive disorder. © The Author(s) 2014.

  6. Das Prinzip Bewegung - Herz und Gehirn als Metaphern des menschlichen Lebens

    NASA Astrophysics Data System (ADS)

    Otis, Laura

    In diesem Jahr, in dem wir Charles Darwins gedenken, möchte ich etwas riskieren und eine Frage erörtern, die für die Literatur ebenso wie für die Biologie zentral ist: Was ist das Leben? Die Antwort auf diese Frage finden wir nicht in der Bibliothek und nicht im Labor, zumindest nicht an diesen erkenntnisproduzierenden Stellen allein. Als Literaturwissenschaftlerin und ehemalige Naturwissenschaftlerin glaube ich, dass wir das Leben nur verstehen werden, wenn wir seinen Wirkungen überall nachforschen, inklusive in der Literatur.

  7. The Deaf Acculturation Scale (DAS): development and validation of a 58-item measure.

    PubMed

    Maxwell-McCaw, Deborah; Zea, Maria Cecilia

    2011-01-01

    This study involved the development and validation of the Deaf Acculturation Scale (DAS), a new measure of cultural identity for Deaf and hard-of-hearing (hh) populations. Data for this study were collected online and involved a nation-wide sample of 3,070 deaf/hh individuals. Results indicated strong internal reliabilities for all the subscales, and construct validity was established by demonstrating that the DAS could discriminate groups based on parental hearing status, school background, and use of self-labels. Construct validity was further demonstrated through factorial analyses, and findings resulted in a final 58-item measure. Directions for future research are discussed.

  8. Anbindung des SISIS-SunRise-Bibliothekssystems an das zentrale Identitätsmanagement

    NASA Astrophysics Data System (ADS)

    Ebner, Ralf; Pretz, Edwin

    Wir berichten über Konzepte und Implementierungen zur Datenprovisionierung aus den Personenverwaltungssystemen der Technischen Universität München (TUM) über das zentrale Metadirectory am Leibniz-Rechenzentrum (LRZ) in das SISIS-SunRise-Bibliothekssystem der Universitätsbibliothek der TUM (TUB). Es werden drei Implementierungsvarianten diskutiert, angefangen von der Generierung und Übertragung einfacher CSV-Dateien über ein OpenLDAP-basiertes Konzept als Backend für die SISIS-Datenbank bis zur endgültigen Implementierung mit dem OCLC IDM Connector.

  9. Longitudinal Change of Biomarkers in Cognitive Decline

    PubMed Central

    Lo, Raymond Y.; Hubbard, Alan E.; Shaw, Leslie M.; Trojanowski, John Q.; Petersen, Ronald C.; Aisen, Paul S.; Weiner, Michael W.; Jagust, William J.

    2017-01-01

    Objective To delineate the trajectories of Aβ42 level in cerebrospinal fluid (CSF), fludeoxyglucose F18 (FDG) uptake using positron emission tomography, and hippocampal volume using magnetic resonance imaging and their relative associations with cognitive change at different stages in aging and Alzheimer disease (AD). Design Cohort study. Setting The 59 study sites for the Alzheimer’s Disease Neuroimaging Initiative. Participants A total of 819 participants 55 to 90 years of age with normal cognition, mild cognitive impairment, and AD who were followed up during the period from 2005 to 2007. Main Outcome Measures Rates of change in level of Aβ42 in CSF, FDG uptake, hippocampal volume, and the Alzheimer Disease’s Assessment Scale–cognitive subscale score during up to 36 months of follow-up by diagnostic group as well as prediction of cognitive change by each biomarker. Results Reductions in the level of Aβ42 in CSF were numerically greater in participants with normal cognition than in participants with mild cognitive impairment or AD; whereas both glucose metabolic decline and hippocampal atrophy were significantly slower in participants with normal cognition than in participants with mild cognitive impairment or AD. Positive APOE4 status accelerated hippocampal atrophic changes in participants with mild cognitive impairment or AD, but did not modify rates of change in level of Aβ42 in CSF or FDG uptake. The Alzheimer Disease’s Assessment Scale–cognitive subscale scores were related only to the baseline level of Aβ42 in CSF and the baseline FDG uptake in participants with normal cognition, which were about equally associated with change in FDG uptake and hippocampal volume in participants with mild cognitive impairment and best modeled by change in FDG uptake in participants with AD. Conclusion Trajectories of Aβ42 level in CSF, FDG uptake, and hippocampal volume vary across different cognitive stages. The longitudinal patterns support a hypothetical

  10. Longitudinal nonlinear wave propagation through soft tissue.

    PubMed

    Valdez, M; Balachandran, B

    2013-04-01

    In this paper, wave propagation through soft tissue is investigated. A primary aim of this investigation is to gain a fundamental understanding of the influence of soft tissue nonlinear material properties on the propagation characteristics of stress waves generated by transient loadings. Here, for computational modeling purposes, the soft tissue is modeled as a nonlinear visco-hyperelastic material, the geometry is assumed to be one-dimensional rod geometry, and uniaxial propagation of longitudinal waves is considered. By using the linearized model, a basic understanding of the characteristics of wave propagation is developed through the dispersion relation and in terms of the propagation speed and attenuation. In addition, it is illustrated as to how the linear system can be used to predict brain tissue material parameters through the use of available experimental ultrasonic attenuation curves. Furthermore, frequency thresholds for wave propagation along internal structures, such as axons in the white matter of the brain, are obtained through the linear analysis. With the nonlinear material model, the authors analyze cases in which one of the ends of the rods is fixed and the other end is subjected to a loading. Two variants of the nonlinear model are analyzed and the associated predictions are compared with the predictions of the corresponding linear model. The numerical results illustrate that one of the imprints of the nonlinearity on the wave propagation phenomenon is the steepening of the wave front, leading to jump-like variations in the stress wave profiles. This phenomenon is a consequence of the dependence of the local wave speed on the local deformation of the material. As per the predictions of the nonlinear material model, compressive waves in the structure travel faster than tensile waves. Furthermore, it is found that wave pulses with large amplitudes and small elapsed times are attenuated over shorter spans. This feature is due to the elevated

  11. Longitudinal Course of Bipolar I Disorder

    PubMed Central

    Solomon, David A.; Leon, Andrew C.; Coryell, William H.; Endicott, Jean; Li, Chunshan; Fiedorowicz, Jess G.; Boyken, Lara; Keller, Martin B.

    2013-01-01

    Context The phenomenology of bipolar I disorder affects treatment and prognosis. Objective To describe the duration of bipolar I mood episodes and factors associated with recovery from these episodes. Design Subjects with Research Diagnostic Criteria bipolar I disorder were prospectively followed up for as long as 25 years. The probability of recovery over time from multiple successive mood episodes was examined with survival analytic techniques, including a mixed-effects grouped-time survival model. Setting Five US academic medical centers. Participants Two hundred nineteen subjects with bipolar I disorder. Main Outcome Measures Level of psychopathology was assessed with the Longitudinal Interval Follow-up Evaluation every 6 months for the first 5 years of follow-up and annually thereafter. Results The median duration of bipolar I mood episodes was 13 weeks. More than 75% of the subjects recovered from their mood episodes within 1 year of onset. The probability of recovery was significantly less for an episode with severe onset (psychosis or severe psychosocial impairment in week 1 of the episode) (hazard ratio [HR]=0.746; 95% confidence interval [CI], 0.578–0.963; P=.02) and for subjects with greater cumulative morbidity (total number of years spent ill with any mood episode) (HR=0.917; 95% CI, 0.886–0.948; P<.001). Compared with the probability of recovery from a major depressive episode, there was a significantly greater probability of recovery from an episode of mania (HR=1.713; 95% CI, 1.373–2.137; P<.001), hypomania (HR=4.502; 95% CI, 3.466–5.849; P<.001), or minor depression (HR = 2.027; 95% CI, 1.622–2.534; P<.001) and, conversely, a significantly reduced probability of recovery from a cycling episode (switching from one pole to the other without an intervening period of recovery) (HR=0.438; 95% CI, 0.351–0.548; P<.001). Conclusions The median duration of bipolar I mood episodes was 13 weeks, and the probability of recovery was significantly

  12. Longitudinal SNP-set association analysis of quantitative phenotypes.

    PubMed

    Wang, Zhong; Xu, Ke; Zhang, Xinyu; Wu, Xiaowei; Wang, Zuoheng

    2017-01-01

    Many genetic epidemiological studies collect repeated measurements over time. This design not only provides a more accurate assessment of disease condition, but allows us to explore the genetic influence on disease development and progression. Thus, it is of great interest to study the longitudinal contribution of genes to disease susceptibility. Most association testing methods for longitudinal phenotypes are developed for single variant, and may have limited power to detect association, especially for variants with low minor allele frequency. We propose Longitudinal SNP-set/sequence kernel association test (LSKAT), a robust, mixed-effects method for association testing of rare and common variants with longitudinal quantitative phenotypes. LSKAT uses several random effects to account for the within-subject correlation in longitudinal data, and allows for adjustment for both static and time-varying covariates. We also present a longitudinal trait burden test (LBT), where we test association between the trait and the burden score in linear mixed models. In simulation studies, we demonstrate that LBT achieves high power when variants are almost all deleterious or all protective, while LSKAT performs well in a wide range of genetic models. By making full use of trait values from repeated measures, LSKAT is more powerful than several tests applied to a single measurement or average over all time points. Moreover, LSKAT is robust to misspecification of the covariance structure. We apply the LSKAT and LBT methods to detect association with longitudinally measured body mass index in the Framingham Heart Study, where we are able to replicate association with a circadian gene NR1D2. © 2016 WILEY PERIODICALS, INC.

  13. Beam Loss and Longitudinal Emittance Growth in SIS

    NASA Astrophysics Data System (ADS)

    Kirk, M.; Hofmann, I.; Boine-Frankenheim, O.; Spiller, P.; Hülsmann, P.; Franchetti, G.; Damerau, H.; König, H. Günter; Klingbeil, H.; Kumm, M.; Moritz, P.; Schütt, P.; Redelbach, A.

    2005-06-01

    Beam losses of several percent occur regularly in SIS. The onset occurs during the RF capture of the beam. Previous studies have revealed that the losses can come from the RF bucket at the start of acceleration being over filled due to the longitudinal bucket acceptance being too small, or due to the mismatch between the mean energy from the UNILAC and synchronous energy of the SIS. The beam losses as measured by a DC beam transformer however show in addition to the sharp initial drop, for the above reasons, a much slower decay in the beam intensity. The speculated cause comes from the incoherent transverse tune shift of the bunched beam, which forces particles into transverse resonant conditions. The longitudinal emittance growth is also another important issue for SIS. Past measurements from Schottky-noise pick-ups have shown a factor of 3-5 increase in the longitudinal emittance depending on the extraction energy; a large factor when compared against expectations from theory. These factors were calculated from the ratio between the normalized relative momentum spread of the DC beam before RF capture and after debunching. In this present work, tomographical techniques have been used to reconstruct the phasespace from a series of bunch profile measurements from a Beam Position Monitor (BPM). Therefore one can find the rate of growth in the longitudinal emittance from a series of high resolution BPM measurements along the RF ramp. Furthermore the initial phasespace density matrix from these reconstructions has been used to generate the initial population of macroparticles for the ESME longitudinal dynamics Particle-In-Cell code, thereby enabling a comparison between the longitudinal emittance growth of the beam under ideal conditions and that of the experiment. The longitudinal emittance growth (rms) during the acceleration (˜540ms) was approximately 20%, and that during the RF capture was estimated to have an upper limit of about 40%. Later measurements have also

  14. Global Longitudinal Strain or Left Ventricular Twist and Torsion? Which Correlates Best with Ejection Fraction?

    PubMed

    Lima, Marcio Silva Miguel; Villarraga, Hector R; Abduch, Maria Cristina Donadio; Lima, Marta Fernandes; Cruz, Cecilia Beatriz Bittencourt Viana; Sbano, João Cesar Nunes; Voos, Mariana Callil; Mathias, Wilson; Tsutsui, Jeane Mike

    2017-07-01

    Estimative of left ventricular ejection fraction (LVEF) is a major indication for echocardiography. Speckle tracking echocardiography (STE) allows analysis of LV contraction mechanics which includes global longitudinal strain (GLS) and twist/torsion, both the most widely used. Direct comparison of correlations between these novel parameters and LVEF has never been done before. This study aims to check which one has the highest correlation with LVEF. Patients with normal LVEF (> 0,55) and systolic dysfunction (LVEF <0,55) were prospectively enrolled, and underwent echocardiogram with STE analysis. Correlation of variables was performed by linear regression analysis. In addition, correlation among levels of LV systolic impairment was also tested. A total of 131 patients were included (mean age, 46 ± 14y; 43%, men). LVEF and GLS showed a strong correlation (r = 0.95; r2 = 0.89; p < 0.001), more evident in groups with LV systolic dysfunction than those with preserved LVEF. Good correlation was also found with global longitudinal strain rate (r = 0.85; r2 = 0.73; p < 0.001). Comparing to GLS, correlation of LVEF and torsional mechanics was weaker: twist (r = 0.78; r2 = 0.60; p < 0.001); torsion (r = 0.75; r2 = 0.56; p < 0.001). GLS of the left ventricle have highly strong positive correlation with the classical parameter of ejection fraction, especially in cases with LV systolic impairment. Longitudinal strain rate also demonstrated a good correlation. GLS increments analysis of LV systolic function. On the other hand, although being a cornerstone of LV mechanics, twist and torsion have a weaker correlation with LV ejection, comparing to GLS. A estimativa da fração de ejeção do ventrículo esquerdo (FEVE) é uma das pincipais indicações para a ecocardiografia. Speckle tracking (ST) permite a análise da mecânica de contração do VE que inclui a deformação (strain) longitudinal global (SLG) e o twist / torção, sendo ambos os mais utilizados. A compara

  15. Landsat 8's atmospheric correction in SeaDAS: comparison with AERONET-OC (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Concha, Javier A.

    2016-09-01

    There is a growing interest in high spatial resolution imagery for the retrieval of biogeochemical components over water to study the processes involved in inland and coastal waters as well as in the open ocean. High spatial resolution satellite presents a kind of different problems to the ones for coarse spatial resolution satellites (i.e. MODIS) for deriving ocean color products (i.e. chlorophyll-a or colored dissolved organic matter at a specific wavelength). The SeaDAS package has recently added the capability to handle Landsat 8 data and to produce ocean color standard products, but validation of the atmospheric correction with in situ data is needed. In this work, different schemes for atmospheric correction within SeaDAS are applied. These schemes include the use of the NIR-SWIR 2, SWIR 1-SWIR 2 combinations, with and without spatial averaging to account for the low signal-to-noise ratio (SNR) in the SWIR bands. The products from the atmospheric correction in SeaDAS, i.e. remote-sensing reflectance (Rrs) at four different wavelengths, are compared with in situ data. This is the first attempt to compare in situ Rrs with the output from SeaDAS/l2gen.

  16. PoroTomo Project - Subatask 6.2: Deploy and Operate DAS and DTS arrays

    SciTech Connect

    Dante Fratta

    2016-03-31

    This metadata submission includes the coordinates of the DAS and DTS surface and borehole arrays, the list of file names, and the list of recorded files during testing at the PoroTomo Natural Laboratory at Brady Hot Spring in Nevada. Testing was completed during March 2016.

  17. The Deaf Acculturation Scale (DAS): Development and Validation of a 58-Item Measure

    ERIC Educational Resources Information Center

    Maxwell-McCaw, Deborah; Zea, Maria Cecilia

    2011-01-01

    This study involved the development and validation of the Deaf Acculturation Scale (DAS), a new measure of cultural identity for Deaf and hard-of-hearing (hh) populations. Data for this study were collected online and involved a nation-wide sample of 3,070 deaf/hh individuals. Results indicated strong internal reliabilities for all the subscales,…

  18. I/O Parallelization for the Goddard Earth Observing System Data Assimilation System (GEOS DAS)

    NASA Technical Reports Server (NTRS)

    Lucchesi, Rob; Sawyer, W.; Takacs, L. L.; Lyster, P.; Zero, J.

    1998-01-01

    The National Aeronautics and Space Administration (NASA) Data Assimilation Office (DAO) at the Goddard Space Flight Center (GSFC) has developed the GEOS DAS, a data assimilation system that provides production support for NASA missions and will support NASA's Earth Observing System (EOS) in the coming years. The GEOS DAS will be used to provide background fields of meteorological quantities to EOS satellite instrument teams for use in their data algorithms as well as providing assimilated data sets for climate studies on decadal time scales. The DAO has been involved in prototyping parallel implementations of the GEOS DAS for a number of years and is now embarking on an effort to convert the production version from shared-memory parallelism to distributed-memory parallelism using the portable Message-Passing Interface (MPI). The GEOS DAS consists of two main components, an atmospheric General Circulation Model (GCM) and a Physical-space Statistical Analysis System (PSAS). The GCM operates on data that are stored on a regular grid while PSAS works with observational data that are scattered irregularly throughout the atmosphere. As a result, the two components have different data decompositions. The GCM is decomposed horizontally as a checkerboard with all vertical levels of each box existing on the same processing element(PE). The dynamical core of the GCM can also operate on a rotated grid, which requires communication-intensive grid transformations during GCM integration. PSAS groups observations on PEs in a more irregular and dynamic fashion.

  19. The Great War and Remembrance in Jose Leon Machado's "Memoria das Estrelas sem Brilho"

    ERIC Educational Resources Information Center

    Azevedo, Milton M.

    2011-01-01

    This article analyzes Jose Leon Machado's novel, "Memoria das Estrelas sem Brilho," as a multilayered historical novel in which a war story provides a background for comments on aspects of early twentieth-century Portuguese society, such as male bonding, religion, sexual mores, and social stratification. (Contains 11 notes.)

  20. Psychometric properties of the Disability Assessment Schedule (DAS) for behavior problems: an independent investigation.

    PubMed

    Tsakanikos, Elias; Underwood, Lisa; Sturmey, Peter; Bouras, Nick; McCarthy, Jane

    2011-01-01

    The present study employed the Disability Assessment Schedule (DAS) to assess problem behaviors in a large sample of adults with ID (N=568) and evaluate the psychometric properties of this instrument. Although the DAS problem behaviors were found to be internally consistent (Cronbach's α=.87), item analysis revealed one weak item ('Objectional habits') with item-total biserial correlation of only .20. An exploratory factor analysis revealed two main factors. The first factor consisted of items relating to disruptive/distractive problems. The second factor consisted of items relating to antisocial/delinquent problems. Disruptive/distractive problems were specifically associated with low ID level. Antisocial/delinquent behaviors were specifically associated with male gender, schizophrenia, hospital admission and troubles with police. For patients who had both disruptive/distractive problems and antisocial/delinquent behaviors, personality disorders and autism were more frequent, where as anxiety and depression were less frequent. On the basis of the obtained results, two new DAS subscales for assessing challenging behavior were proposed. Both subscales had good levels of internal consistency, as well as face and criterion validity. Overall, the new DAS subscales were shown to have acceptable psychometric properties and have therefore potential for use in both research and clinical practice. Copyright © 2010 Elsevier Ltd. All rights reserved.

  1. The Great War and Remembrance in Jose Leon Machado's "Memoria das Estrelas sem Brilho"

    ERIC Educational Resources Information Center

    Azevedo, Milton M.

    2011-01-01

    This article analyzes Jose Leon Machado's novel, "Memoria das Estrelas sem Brilho," as a multilayered historical novel in which a war story provides a background for comments on aspects of early twentieth-century Portuguese society, such as male bonding, religion, sexual mores, and social stratification. (Contains 11 notes.)

  2. The Deaf Acculturation Scale (DAS): Development and Validation of a 58-Item Measure

    ERIC Educational Resources Information Center

    Maxwell-McCaw, Deborah; Zea, Maria Cecilia

    2011-01-01

    This study involved the development and validation of the Deaf Acculturation Scale (DAS), a new measure of cultural identity for Deaf and hard-of-hearing (hh) populations. Data for this study were collected online and involved a nation-wide sample of 3,070 deaf/hh individuals. Results indicated strong internal reliabilities for all the subscales,…

  3. MiDAS: the field guide to the microbes of activated sludge

    PubMed Central

    McIlroy, Simon Jon; Saunders, Aaron Marc; Albertsen, Mads; Nierychlo, Marta; McIlroy, Bianca; Hansen, Aviaja Anna; Karst, Søren Michael; Nielsen, Jeppe Lund; Nielsen, Per Halkjær

    2015-01-01

    The Microbial Database for Activated Sludge (MiDAS) field guide is a freely available online resource linking the identity of abundant and process critical microorganisms in activated sludge wastewater treatment systems to available data related to their functional importance. Phenotypic properties of some of these genera are described, but most are known only from sequence data. The MiDAS taxonomy is a manual curation of the SILVA taxonomy that proposes a name for all genus-level taxa observed to be abundant by large-scale 16 S rRNA gene amplicon sequencing of full-scale activated sludge communities. The taxonomy can be used to classify unknown sequences, and the online MiDAS field guide links the identity to the available information about their morphology, diversity, physiology and distribution. The use of a common taxonomy across the field will provide a solid foundation for the study of microbial ecology of the activated sludge process and related treatment processes. The online MiDAS field guide is a collaborative workspace intended to facilitate a better understanding of the ecology of activated sludge and related treatment processes—knowledge that will be an invaluable resource for the optimal design and operation of these systems. Database URL: http://www.midasfieldguide.org PMID:26120139

  4. Incorporating Parallel Computing into the Goddard Earth Observing System Data Assimilation System (GEOS DAS)

    NASA Technical Reports Server (NTRS)

    Larson, Jay W.

    1998-01-01

    Atmospheric data assimilation is a method of combining actual observations with model forecasts to produce a more accurate description of the earth system than the observations or forecast alone can provide. The output of data assimilation, sometimes called the analysis, are regular, gridded datasets of observed and unobserved variables. Analysis plays a key role in numerical weather prediction and is becoming increasingly important for climate research. These applications, and the need for timely validation of scientific enhancements to the data assimilation system pose computational demands that are best met by distributed parallel software. The mission of the NASA Data Assimilation Office (DAO) is to provide datasets for climate research and to support NASA satellite and aircraft missions. The system used to create these datasets is the Goddard Earth Observing System Data Assimilation System (GEOS DAS). The core components of the the GEOS DAS are: the GEOS General Circulation Model (GCM), the Physical-space Statistical Analysis System (PSAS), the Observer, the on-line Quality Control (QC) system, the Coupler (which feeds analysis increments back to the GCM), and an I/O package for processing the large amounts of data the system produces (which will be described in another presentation in this session). The discussion will center on the following issues: the computational complexity for the whole GEOS DAS, assessment of the performance of the individual elements of GEOS DAS, and parallelization strategy for some of the components of the system.

  5. A Brief History of the J.P. Das Developmental Disabilities Centre

    ERIC Educational Resources Information Center

    Sobsey, Dick

    2008-01-01

    The J.P. Das Developmental Disabilities Centre celebrated its 40th anniversary on September 1, 2007, followed by The University of Alberta's 100th anniversary in 2008. The year 2008 also brought the appointment of a new Director for the Centre. As the immediate past Director of the Centre, the author recounts some of the history of the J.P. Das…

  6. Abpfiff für das Fußball-Universum

    NASA Astrophysics Data System (ADS)

    Bartelmann, Matthias

    2005-03-01

    Aus Beobachtungen der kosmischen Hintergrundstrahlung lassen sich zwar Rückschlüsse auf die Größe und die Topologie des Universums ziehen. Die Behauptung, aus den Daten des Satelliten WMap würde folgen, dass das Universum endlich groß sei und die Topologie eines Dodekaeders aufweise, wurde jedoch widerlegt.

  7. MiDAS: the field guide to the microbes of activated sludge.

    PubMed

    McIlroy, Simon Jon; Saunders, Aaron Marc; Albertsen, Mads; Nierychlo, Marta; McIlroy, Bianca; Hansen, Aviaja Anna; Karst, Søren Michael; Nielsen, Jeppe Lund; Nielsen, Per Halkjær

    2015-01-01

    The Microbial Database for Activated Sludge (MiDAS) field guide is a freely available online resource linking the identity of abundant and process critical microorganisms in activated sludge wastewater treatment systems to available data related to their functional importance. Phenotypic properties of some of these genera are described, but most are known only from sequence data. The MiDAS taxonomy is a manual curation of the SILVA taxonomy that proposes a name for all genus-level taxa observed to be abundant by large-scale 16 S rRNA gene amplicon sequencing of full-scale activated sludge communities. The taxonomy can be used to classify unknown sequences, and the online MiDAS field guide links the identity to the available information about their morphology, diversity, physiology and distribution. The use of a common taxonomy across the field will provide a solid foundation for the study of microbial ecology of the activated sludge process and related treatment processes. The online MiDAS field guide is a collaborative workspace intended to facilitate a better understanding of the ecology of activated sludge and related treatment processes--knowledge that will be an invaluable resource for the optimal design and operation of these systems. © The Author(s) 2015. Published by Oxford University Press.

  8. Reisen im freien Fall - Teil 2: Das Zwillingsparadoxon aus dem Blickwinkel der ART

    NASA Astrophysics Data System (ADS)

    Sonne, Bernd; Weiß, Reinhard

    2013-07-01

    Nachdem wir uns mit den Prinzipien der ART und einigen Beispielen vertraut gemacht haben, kommen wir nun zur Berechnung des Zwillingsparadoxons aus Sicht des reisenden Zwillings. Dabei spielt das Äquivalenzprinzip eine große Rolle. Deshalb wird die Bewegungssituation noch einmal erläutert, diesmal aus Sicht von Katrin. Sie befindet sich in ihrem System S'in Ruhe. In ihrem System läuft die Zeit t'ab. Nach dem Start fühlt Katrin jedoch eine Kraft, die sie als Gravitationskraft interpretieren kann. Sie merkt es daran, dass sie in den Sitz gedrückt wird. Nach einiger Zeit werden die Triebwerke abgeschaltet, und das Raumschiff fliegt mit konstanter Geschwindigkeit weiter, Phase 2. Anschließend wird der Schub der Triebwerke solange umgekehrt, bis das Raumschiff irgendwo mit der Geschwindigkeit null am Umkehrpunkt U landet, Phase 3 (Abb. 15.1). Die Erde, auf der sich Michael befindet, bewegt sich mit x'(t') aus Sicht von Katrin im freien Fall von ihr weg, s. das Experiment mit dem steigenden Fahrstuhl in Abschn. 13.2.1.

  9. A multiple imputation strategy for incomplete longitudinal data.

    PubMed

    Landrum, M B; Becker, M P

    Longitudinal studies are commonly used to study processes of change. Because data are collected over time, missing data are pervasive in longitudinal studies, and complete ascertainment of all variables is rare. In this paper a new imputation strategy for completing longitudinal data sets is proposed. The proposed methodology makes use of shrinkage estimators for pooling information across geographic entities, and of model averaging for pooling predictions across different statistical models. Bayes factors are used to compute weights (probabilities) for a set of models considered to be reasonable for at least some of the units for which imputations must be produced, imputations are produced by draws from the predictive distributions of the missing data, and multiple imputations are used to better reflect selected sources of uncertainty in the imputation process. The imputation strategy is developed within the context of an application to completing incomplete longitudinal variables in the so-called Area Resource File. The proposed procedure is compared with several other imputation procedures in terms of inferences derived with the imputations, and the proposed methodology is demonstrated to provide valid estimates of model parameters when the completed data are analysed. Extensions to other missing data problems in longitudinal studies are straightforward so long as the missing data mechanism can be assumed to be ignorable.

  10. Diseased Region Detection of Longitudinal Knee Magnetic Resonance Imaging Data

    PubMed Central

    Huang, Chao; Shan, Liang; Charles, H. Cecil; Wirth, Wolfgang; Niethammer, Marc; Zhu, Hongtu

    2015-01-01

    Magnetic resonance imaging (MRI) has become an important imaging technique for quantifying the spatial location and magnitude/direction of longitudinal cartilage morphology changes in patients with osteoarthritis (OA). Although several analytical methods, such as subregion-based analysis, have been developed to refine and improve quantitative cartilage analyses, they can be suboptimal due to two major issues: the lack of spatial correspondence across subjects and time and the spatial heterogeneity of cartilage progression across subjects. The aim of this paper is to present a statistical method for longitudinal cartilage quantification in OA patients, while addressing these two issues. The 3D knee image data is preprocessed to establish spatial correspondence across subjects and/or time. Then, a Gaussian hidden Markov model (GHMM) is proposed to deal with the spatial heterogeneity of cartilage progression across both time and OA subjects. To estimate unknown parameters in GHMM, we employ a pseudo-likelihood function and optimize it by using an expectation-maximization (EM) algorithm. The proposed model can effectively detect diseased regions in each OA subject and present a localized analysis of longitudinal cartilage thickness within each latent subpopulation. Our GHMM integrates the strengths of two standard statistical methods including the local subregion-based analysis and the ordered value approach. We use simulation studies and the Pfizer longitudinal knee MRI dataset to evaluate the finite sample performance of GHMM in the quantification of longitudinal cartilage morphology changes. Our results indicate that GHMM significantly outperforms several standard analytical methods. PMID:25823031

  11. Theoretical study of transverse-longitudinal emittance coupling

    SciTech Connect

    Qin, H; Davidson, R C; Chung, M; Barnard, J J; Wang, T F

    2011-04-14

    The effect of a weakly coupled periodic lattice in terms of achieving emittance exchange between the transverse and longitudinal directions is investigated using the generalized Courant-Snyder theory for coupled lattices. Recently, the concept and technique of transverse-longitudinal emittance coupling have been proposed for applications in the Linac Coherent Light Source and other free-electron lasers to reduce the transverse emittance of the electron beam. Such techniques can also be applied to the driver beams for the heavy ion fusion and beam-driven high energy density physics, where the transverse emittance budget is typically tighter than the longitudinal emittance. The proposed methods consist of one or several coupling components which completely swap the emittances of one of the transverse directions and the longitudinal direction at the exit of the coupling components. The complete emittance exchange is realized in one pass through the coupling components. In the present study, we investigate the effect of a weakly coupled periodic lattice in terms of achieving emittance exchange between the transverse and longitudinal directions. A weak coupling component is introduced at every focusing lattice, and we would like to determine if such a lattice can realize the function of emittance exchange.

  12. Performance of broiler chickens fed diets containing DAS-68416-4 soybean meal.

    PubMed

    Herman, Rod A; Dunville, Christina M; Juberg, Daland R; Fletcher, Dale W; Cromwell, Gary L

    2011-01-01

    Broiler chickens are a fast growing monogastric animal commonly used to evaluate the equivalence between transgenic and non-transgenic grains as part of the human safety assessment process. While commonly viewed like other livestock feeding trials, such studies are performed with transgenic crops with input traits (that are not designed to improve nutrition) to aid regulatory authorities in evaluating safety. Studies of this type are actually more similar to toxicology studies in purpose, with sensitive endpoints like growth used to detect metabolic perturbations. DAS-68416-4 soybean expresses the aryloxyalkanoate dioxygenase-12 (AAD-12) enzyme which inactivates 2,4-diclorophenoxyacetic acid (2,4-D) and provides DAS-68416-4 soybeans tolerance to this herbicide. DAS-68416-4 also expresses the phosphinothricin acetyltransferase (PAT) enzyme from Streptomyces viridochromogenes which confers tolerance to glufosinate-ammonium herbicides. A 6-week broiler study was conducted with diets containing toasted DAS-68416-4 soybean meal (40, 36, and 32% in starter, grower and finisher diets, respectively) to evaluate nutritional wholesomeness and safety compared with conventional comparators. Toasting soybean meal is required to inactivate endogenous antinutrients making soybean suitable for consumption by monogastric animals like broiler chickens. Toasting was found to denature both the AAD-12 and PAT proteins rendering them non-detectable by enzyme linked immunosorbent assays. Broiler growth and performance parameters were measured over a 6-week period of exposure to diets containing different sources of toasted soybean meal, and results indicate that DAS-68416-4 soybean is nutritionally equivalent to non-transgenic soybean.

  13. A 90 day chronic toxicity study of Nigerian herbal preparation DAS-77 in rats

    PubMed Central

    2012-01-01

    Background The herbal preparation DAS-77, used for the treatment of various ailments in Nigeria, contains the milled bark of Mangifera indica L. and root of Carica papaya L. Toxicological assessment of the preparation was carried out in this study. Methods In the acute toxicity study, DAS-77 was administered to mice p.o. up to 20 g/kg in divided doses and i.p. at 250–3000 mg/kg. Mortality within 24 h was recorded. In the chronic toxicity study, rats were treated p.o. for 90 days at doses of 80, 400 (therapeutic dose, TD) and 2000 mg/kg. By 90 days, animals were sacrificed and blood samples collected for hematological and biochemical analysis. Organs were harvested for weight determination, antioxidants and histopathological assessments. Results DAS-77 did not produce any lethality administered p.o. up to 20 g/kg in divided doses but the i.p. LD50 was 1122.0 mg/kg. At TD, DAS-77 produced significant (p < 0.05) reductions in body weight, food intake and K+, and increases in ovary weight, neutrophils and HDL, which were reversible. Histopathological presentations were generally normal. Effects at the other doses were comparable to those at TD except for reversible increases in antioxidants in the liver, kidney and testes, and sperm abnormality, and reductions in liver enzymes, sperm motility and count. Conclusions Findings in this study revealed that DAS-77 is relatively safe with the potential for enhancing in vivo antioxidant activity. However, possibly reversible side-effects include electrolyte imbalance and sterility in males. PMID:22892317

  14. DAS steered therapy in clinical practice; cross-sectional results from the METEOR database.

    PubMed

    Gvozdenović, Emilia; Wolterbeek, Ron; van der Heijde, Désirée; Huizinga, Tom; Allaart, Cornelia; Landewé, Robert

    2016-01-16

    Little is known on how well targeted treatment, for instance targeting towards low DAS, is implemented in clinical practice. Our aim was to evaluate treatment adjustments in response to DAS in RA patients in clinical practice. We used data from one referral centre, multiple rheumatologists, from the METEOR database. Generalized Estimating Equations (GEE) were used to assess whether in case of non-low disease activity (DAS > 2.4) treatment intensifications in DMARD therapy occurred ((change or increase in dose or number of DMARDs, including synthetic (s)DMARDs, biologic (b)DMARDs and corticosteroids compared to the visit before)). Determinants of not intensifying the treatment when DAS > 2.4 were investigated using GEE. Five thousand one hundred fifty-seven registered visits of 1202 patients were available for the analyses. A DAS > 2.4 was weakly (OR: 1.19; 95% CI 1.07-1.33) associated with a treatment intensification. In 69% (n = 3577) of the visits patients were in low disease activity. In 66% (n = 1028) of the visits with DAS > 2.4 treatment was not intensified. These patients had a higher tender joint count and received more often methotrexate plus a bDMARD, or csDMARD monotherapy, as compared to patients that received treatment intensification. In the majority of visits in the METEOR database patients were already in a state of low disease activity, reflecting appropriate treatment intensity. When DAS was greater than 2.4, treatment was often not intensified due to high tender joint count or specific treatment combinations. This data suggest that while aiming for low DAS, physicians per patient weigh whether all DAS elements indicate disease activity or will respond to DMARD adjustment or not, and make treatment decisions accordingly.

  15. 50 CFR 648.53 - Acceptable biological catch (ABC), annual catch limits (ACL), annual catch targets (ACT), DAS...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... catch limits (ACL), annual catch targets (ACT), DAS allocations, and individual fishing quotas (IFQ... limits (ACL), annual catch targets (ACT), DAS allocations, and individual fishing quotas (IFQ). (a... limited access scallop fishery shall be allocated 94.5 percent of the ACL specified in paragraph (a)(1)...

  16. A Letter to the Parent(s) of a Child with Developmental Apraxia of Speech. Part IV: Treatment of DAS.

    ERIC Educational Resources Information Center

    Hall, Penelope K.

    2000-01-01

    One of a series of letters to parents of children with developmental apraxia of speech (DAS), this letter discusses the treatment of DAS including linguistic approaches, motor-programming approaches, a combination of linguistic and motor-programming approaches, and treatment approaches that include specific sensory and gestural cueing techniques.…

  17. A Letter to the Parent(s) of a Child with Developmental Apraxia of Speech. Part IV: Treatment of DAS.

    ERIC Educational Resources Information Center

    Hall, Penelope K.

    2000-01-01

    One of a series of letters to parents of children with developmental apraxia of speech (DAS), this letter discusses the treatment of DAS including linguistic approaches, motor-programming approaches, a combination of linguistic and motor-programming approaches, and treatment approaches that include specific sensory and gestural cueing techniques.…

  18. Evaluation of the activity of rheumatoid arthritis in clinical practice. Agreement between self-rated clinimetric evaluation and clinical evaluation with activity indexes: DAS28, CDAI and SDAI.

    PubMed

    Horta-Baas, Gabriel; Pérez Bolde-Hernández, Arturo; Hernández-Cabrera, María Fernanda; Vergara-Sánchez, Imelda; Romero-Figueroa, María Del Socorro

    2017-10-11

    To achieve control of rheumatoid arthritis (RA) it is necessary to be able to evaluate its activity. The American College of Rheumatology (ACR) recommends for this purpose indexes of activity that can be performed by the patient (PAS-II and RAPID-3) and IA including medical evaluation with laboratory studies (DAS28 and SDAI) or without them (CDAI). The objective was to analyze the concordance between self-rated clinimetric evaluation and clinimetric evaluation performed by the physician. Analytical cross-sectional study in 126 patients with RA. The agreement was evaluated through the weighted κ coefficient and the Krippendorff's α coefficient. The PAS-II and RAPID-3 significantly correlated with all variables included in the core set of measures recommended by the ACR/EULAR. The agreement between PAS-II and CDAI-SDAI was good (κ: 0.6, α: 0.61-0.62), and moderate with DAS28-ESR (κ: 0.53, α: 0.56). The concordance between RAPID-3 and CDAI-SDAI was moderate (κ: 0.55-0.57, α: 0.50-0.51), and moderate with DAS28-ESR (κ: 0.55, α: 0.53). When categorizing the activity in remission/low activity vs. moderate/severe activity, the agreement was greater with the PAS-II (0.59 vs. 0.34; P=.012). The good concordance between PAS-II and SDAI supports their use in clinical practice, especially if biomarkers of inflammation or the possibility of joint count are not available. However, in order to recommend its routine application in clinical practice, it is necessary to perform longitudinal studies that assess its responsiveness. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

  19. Adherence to combination DMARD therapy and treatment outcomes in rheumatoid arthritis: a longitudinal study of new and existing DMARD users.

    PubMed

    Wabe, Nasir; Lee, Anita; Wechalekar, Mihir; McWilliams, Leah; Proudman, Susanna; Wiese, Michael

    2017-02-03

    Medication adherence is believed to be a major contributor to treatment outcomes yet studies quantifying this relationship as rare in rheumatoid arthritis (RA). To determine the association of adherence to DMARD therapy with treatment outcomes among new and existing DMARD users over 2 years. Relevant clinical parameters were obtained from a longitudinal cohort of RA patients, most of who were treated with combination therapy. Patients were classified as adherent if the proportion of days covered for each DMARD was ≥80%. Outcome measures were the change in the disease activity score in 28 joints (DAS28), simplified disease activity index (SDAI), modified health assessment questionnaires (mHAQ) and proportion of patients who achieved response criteria. An inverse propensity-score weighting method was used to estimate the association of adherence with each outcome. Of 194 patients invited, a total of 111 patients (new = 45 and existing = 66 DMARD users) met study eligibility. DMARD-naive patients demonstrated relatively higher rates of adherence compared to existing users. After controlling for confounding variables, adherence was significantly associated with reduction in DAS28 (β = -1.5, 95% CI of β = - 2.17 to -0.83, p < 0.0001), SDAI (β = -9.44, 95% CI of β = -15.53 to -3.35, p = 0.002) and mHAQ (β = -0.269, 95% CI of β, -0.462 to -0.077, p = 0.017) over 2 years among new patients and adherent patients were more likely to achieve most response criteria compared to non-adherent patients. Such associations were not replicated among existing DMARD users. Adherence to combination DMARD therapy was associated with improvements in disease activity and functional outcomes in the first 2 years of therapy.

  20. Exploratory analysis of longitudinal trials with staggered intervention times.

    PubMed

    Sousa, Inês; Chetwynd, Amanda G; Diggle, Peter J

    2005-07-01

    Longitudinal trials involving surgical interventions commonly have subject-specific intervention times, due to constraints on the availability of surgeons and operating theatres. Moreover, the intervention often effects a discontinuous change in the mean response. We propose a nonparametric estimator for the mean response profile of longitudinal data with staggered intervention times and a discontinuity at the times of intervention, as an exploratory tool to assist the formulation of a suitable parametric model. We use an adaptation of the standard generalized additive model algorithm for estimation, with smoothing constants chosen by a cross-validation criterion. We illustrate the method using longitudinal data from a trial to assess the effect of lung resection surgery in the treatment of emphysema patients.

  1. Longitudinal beam dynamics for heavy ion fusion using WARPrz

    SciTech Connect

    Callahan, D.A.; Langdon, A.B.; Friedman, A.; Haber, I.

    1993-02-22

    WARPrz is a 2.5 dimensional, cylindrically symmetric, electrostatic, particle-in-cell code. It is part of the WARP family of codes which has been developed to study heavy ion fusion driver issues. WARPrz is being used to study the longitudinal dynamics of heavy ion beams including a longitudinal instability that is driven by the impedance of the LINAC accelerating modules. This instability is of concern because it can enhance longitudinal momentum spread; chromatic abhoration in the lens system restricts the amount of momentum spread allowed in the beam in the final focusing system. The impedance of the modules is modeled by a continuum of resistors and capacitors in parallel in WARPrz. We discuss simulations of this instability including the effect of finite temperature and reflection of perturbations off the beam ends. We also discuss intermittency of axial confining fields (``ears`` fields) as a seed for this instability.

  2. Procedure of measuring the longitudinal emittance of electron beam

    NASA Astrophysics Data System (ADS)

    Vladimirov, I. Yu

    2016-09-01

    The procedure of measuring the longitudinal emittance of electron beam generated by RF gun and reconstruction of its longitudinal phase portrait is proposed. Measuring system consists of vertical deflecting RF cavity, horizontal bending dipole and screen. The beam spot on the screen is used to reconstruct the longitudinal phase portrait. In the proposed procedure an electromagnetic field of the vertical deflecting RF cavity can be approximated by the TM110 mode of pillbox cavity. This approximation allows analytically solve the motion equations of the electron motion in the vertical deflecting RF cavity. The report contains description of the vertical deflecting RF cavity and the dipole, the formulae underlying the procedure and the results of numerical simulation.

  3. Using Administrative Data for Longitudinal Substance Abuse Research

    PubMed Central

    Evans, Elizabeth; Grella, Christine E.; Murphy, Debra A.; Hser, Yih-Ing

    2008-01-01

    The utilization of administrative data in substance abuse research has become more widespread than ever. This selective review synthesizes recent extant research from 31 articles to consider what has been learned from using administrative data to conduct longitudinal substance abuse research in four overlapping areas: (1) service access and utilization, (2) underrepresented populations, (3) treatment outcomes, and (4) cost analysis. Despite several notable limitations, administrative data contribute valuable information, particularly in the investigation of service system interactions and outcomes among substance abusers as they unfold and influence each other over the long term. This critical assessment of the advantages and disadvantages of using existing administrative data within a longitudinal framework should stimulate innovative thinking regarding future applications of administrative data for longitudinal substance abuse research purposes. PMID:18679805

  4. Longitudinal image registration with non-uniform appearance change.

    PubMed

    Csapo, Istvan; Davis, Brad; Shi, Yundi; Sanchez, Mar; Styner, Martin; Niethammer, Marc

    2012-01-01

    Longitudinal imaging studies are frequently used to investigate temporal changes in brain morphology. Image intensity may also change over time, for example when studying brain maturation. However, such intensity changes are not accounted for in image similarity measures for standard image registration methods. Hence, (i) local similarity measures, (ii) methods estimating intensity transformations between images, and (iii) metamorphosis approaches have been developed to either achieve robustness with respect to intensity changes or to simultaneously capture spatial and intensity changes. For these methods, longitudinal intensity changes are not explicitly modeled and images are treated as independent static samples. Here, we propose a model-based image similarity measure for longitudinal image registration in the presence of spatially non-uniform intensity change.

  5. [The problem of repeated measurements. Longitudinal analysis in epidemiology].

    PubMed

    Sáez, M

    2001-01-01

    In longitudinal analyses subjects are repeatedly measured along time. They are mixed designs, characterised for their simultaneous consideration of two or more dimensions of analysis, in which time is one of the dimensions.Longitudinal analyses have important advantages with respect other designs. The most important is that they are more efficient, since they allow to distinguish between-individual and within-individual variation.Longitudinal analyses can be approached marginal and conditionally. Whereas the former allows to draw poblational, or average, inferences, the latter permits to draw individual inferences.The statistical models to use depend on the type of response variable. If the dependent variable is normally distributed one will use linear mixed models. When the response is a count one will use mixed Poisson regressions. Mixed binomial or multinomial logistic regressions should be used when the response would be categorical.

  6. Simulation of the ALS longitudinal multibunch feedback system

    SciTech Connect

    Byrd, J.

    1993-05-01

    Longitudinal coupled bunch growth rates in the Advanced Light Source (ALS), a 1.5 GeV electron storage ring for producing synchrotron radiation, indicate the need for damping via a feedback (FB) system. The design of the system is based on the proposed PEP-II longitudinal FB system which uses a digital filter to provide the required phase and amplitude response. We report the results of a detailed computer simulation of the FB system including single particle longitudinal beam dynamics, measured RF cavity fundamental and higher order modes, and response of major FB components such as the power amplifier and kicker. The simulation addresses issues such as required FB power and gain, noise, digital filter effects, and varying initial bunch conditions.

  7. Young's modulus of BF wood material by longitudinal vibration

    NASA Astrophysics Data System (ADS)

    Phadke, Sushil; Darshan Shrivastava, Bhakt; Mishra, Ashutosh; Dagaonkar, N.

    2014-09-01

    All engineered structures are designed and built with consideration of resisting the same fundamental forces of tension, compression, shear, bending and torsion. Structural design is a balance of these internal and external forces. So, it is interesting to calculate the Young's moduli of Borassus Flabellifier BF wood are quite important from the application point of view. The ultrasonic waves are closely related with the elastic and inelastic properties of the materials. In the present study, we measured longitudinal wave ultrasonic velocities in BF wood material by longitudinal vibration method. After measuring ultrasonic velocity in BF wood material, we calculated Young's modulus of Borassus Flabellifier BF wood material. We used ultrasonic interferometer for measuring longitudinal wave ultrasonic velocity in BF wood material made by Mittal Enterprises, New Delhi, India in our laboratory. Borassus Flabellifier BF wood material was collected from Dhar district of Madhya Pradesh, India.

  8. Nonlinear Cascade Strategy for Longitudinal Control of Electric Vehicle.

    PubMed

    El Majdoub, K; Giri, F; Ouadi, H; Chaoui, F Z

    2014-01-01

    The problem of controlling the longitudinal motion of front-wheels electric vehicle (EV) is considered making the focus on the case where a single dc motor is used for both front wheels. Chassis dynamics are modelled applying relevant fundamental laws taking into account the aerodynamic effects and the road slope variation. The longitudinal slip, resulting from tire deformation, is captured through Kiencke's model. Despite its highly nonlinear nature the complete model proves to be utilizable in longitudinal control design. The control objective is to achieve a satisfactory vehicle speed regulation in acceleration/deceleration stages, despite wind speed and other parameters uncertainty. An adaptive controller is developed using the backstepping design technique. The obtained adaptive controller is shown to meet its objectives in presence of the changing aerodynamics efforts and road slope.

  9. Longitudinal research with sexual assault survivors: a methodological review.

    PubMed

    Campbell, Rebecca; Sprague, Heather Brown; Cottrill, Sara; Sullivan, Cris M

    2011-02-01

    Longitudinal research designs are relatively rare in the academic literature on rape and sexual assault despite their tremendous methodological rigor and scientific utility. In the interest of promoting wider use of such methods, we conducted a methodological review of projects that have used prospective longitudinal designs to study the occurrence of sexual victimization throughout the lifespan and/or the process of change during rape recovery (N = 32 projects). Five questions were examined: (a) What were the substantive foci of these longitudinal studies? (b) How were survivors recruited? (c) What participation rates were typical? (d) How long were participants followed over time and with what success rates? and (e) What incentives were used to increase participation? Most studies focused on postassault sequelae and recruited survivors from hospital emergency departments and other first-response help-seeking sites with highly variable participation rates. Retention rates were comparable across studies (approximately 70%).

  10. Longitudinal-bending mode micromotor using multilayer piezoelectric actuator.

    PubMed

    Yao, K; Koc, B; Uchino, K

    2001-07-01

    Longitudinal-bending mode ultrasonic motors with a diameter of 3 mm were fabricated using stacked multilayer piezoelectric actuators, which were self-developed from hard lead zirconate titanate (PZT) ceramic. A bending vibration was converted from a longitudinal vibration with a longitudinal-bending coupler. The motors could be bidirectionally operated by changing driving frequency. Their starting and braking torque were analyzed based on the transient velocity response. With a load of moment of inertia 2.5 x 10(-7) kgm2, the motor showed a maximum starting torque of 127.5 microNm. The braking torque proved to be a constant independent on the motor's driving conditions and was roughly equivalent to the maximum starting torque achievable with our micromotors.

  11. Longitudinal evidence for diminished frontal cortex function in aging

    PubMed Central

    Nyberg, Lars; Salami, Alireza; Andersson, Mikael; Eriksson, Johan; Kalpouzos, Grégoria; Kauppi, Karolina; Lind, Johanna; Pudas, Sara; Persson, Jonas; Nilsson, Lars-Göran

    2010-01-01

    Cross-sectional estimates of age-related changes in brain structure and function were compared with 6-y longitudinal estimates. The results indicated increased sensitivity of the longitudinal approach as well as qualitative differences. Critically, the cross-sectional analyses were suggestive of age-related frontal overrecruitment, whereas the longitudinal analyses revealed frontal underrecruitment with advancing age. The cross-sectional observation of overrecruitment reflected a select elderly sample. However, when followed over time, this sample showed reduced frontal recruitment. These findings dispute inferences of true age changes on the basis of age differences, hence challenging some contemporary models of neurocognitive aging, and demonstrate age-related decline in frontal brain volume as well as functional response. PMID:21156826

  12. Longitudinal statistics of plasma bubbles: Possible tropospheric influence

    NASA Astrophysics Data System (ADS)

    Sidorova, L. N.; Filippov, S. V.

    2016-07-01

    The assumption about the possible influence of a tropospheric source on the nature of the longitudinal statistics variation (relative frequency of observation) of plasma bubbles determined by the He+ density in the upper ionosphere altitudes is tested. To do this, the statistics are comparatively analyzed with a number of characteristics of the ionosphere and thermosphere, the longitudinal changes of which can be related to the DE3 tidal wave generated in the troposphere. Evidence of the possible influence of the troposphere on the longitudinal statistics of plasma bubbles has been obtained. Based on qualitative analysis, it was found that the thermospheric winds modulated by the DE3 tidal wave can link these statistics with processes in the troposphere.

  13. dnaA suppressor (dasF) mutants of Escherichia coli are stable DNA replication (sdrA/rnh) mutants.

    PubMed

    Torrey, T A; Atlung, T; Kogoma, T

    1984-01-01

    The possible allelic relationship between dasF (dnaA suppressor) and sdrA/rnh (stable DNA replication/RNase H) mutations was examined. dasF mutations could not only suppress various dnaA(ts) mutations, but also the insertional inactivation of the dnaA gene or deletion of the oriC sequence, as could sdrA mutations. dasF mutants were found to exhibit the stable DNA replication phenotype, and the sensitivity to rich media, of sdrA mutants. The dasF and sdrA mutations were mapped very closely between metD and proA on the E. coli genetic map. The mutations were recessive to the wild-type allele for all the above phenotypes. It was concluded that dasF is allelic to sdrA/mh.

  14. Longitudinal and Seasonal Variation of Lunar tide strength

    NASA Astrophysics Data System (ADS)

    Yizengaw, E.; Pacheco, E. E.; Valladares, C. E.

    2012-12-01

    It has been known since many decades that lunar tide, which manifests itself as a semi-diurnal wave that precesses through all local times within one lunar month, has been identified as a significant force that can produce a notable influence on the longitudinal equatorial density distribution and equatorial electrojet (EEJ). However, there has never been a comprehensive study, except some statistical analysis using the satellite based in-situ observations, of the lunar tide effect on a global scale. This left several questions, like the longitudinal and solar flux dependence of the lunar tide, the tidal wave strength difference between new and full moon phases, remained unanswered. The proximity of the Earth/Moon system to the Sun, proximity of a New/Full Moon to one of the nodes of the lunar orbit, and the proximity of a New/Full Moon to the perigee of the lunar orbit are among the main factors that can affect the seasonal variability of lunar tide strength. With the indications of lunar tide influence on the strength of dayside EEJ, enhancing EEJ's strength shortly after new and full moon, we utilize the ground-based magnetometer fourteen years (1998 - 2012) data and investigate the various aspects of lunar tide effects on the EEJ at three different longitudinal sectors. The equatorial magnetometers located at Jicamarca for American sector, Addis Ababa for African sector, and Tirunelveli for Indian sector are used for this comprehensive study. Simultaneously, using the GPS TEC data, we examined the lunar tide impacts on the equatorial density irregularities and bubble formations at different longitudinal sectors. We found surprising strong longitudinal dependence in the lunar tide strength and its influence on EEJ and density bubble formation. Significant solar flux and seasonal dependences in lunar tide strength have also been observed at all longitudinal sectors. Finally, we investigated the lunar tide strength difference between new moon and full moon phases.

  15. A dynamic trajectory class model for intensive longitudinal categorical outcome.

    PubMed

    Lin, Haiqun; Han, Ling; Peduzzi, Peter N; Murphy, Terrence E; Gill, Thomas M; Allore, Heather G

    2014-07-10

    This paper presents a novel dynamic latent class model for a longitudinal response that is frequently measured as in our prospective study of older adults with monthly data on activities of daily living for more than 10 years. The proposed method is especially useful when the longitudinal response is measured much more frequently than other relevant covariates. The trajectory classes are latent classes that represent distinct temporal patterns of the longitudinal response wherein an individual may remain in a trajectory class or switch to another as the class membership predictors are updated periodically over time. The identification of a common set of trajectory classes allows changes among the temporal patterns to be distinguished from local fluctuations in the response. Within a trajectory class, the longitudinal response is modeled by a class-specific generalized linear mixed model. An informative event such as death is jointly modeled by class-specific probability of the event through shared random effects with that for the longitudinal response. We do not impose the conditional independence assumption given the classes. We illustrate the method by analyzing the change over time in activities of daily living trajectory class among 754 older adults with 70,500 person-months of follow-up in the Precipitating Events Project. We also investigate the impact of jointly modeling the class-specific probability of the event on the parameter estimates in a simulation study. The primary contribution of our paper is the periodic updating of trajectory classes for a longitudinal categorical response without assuming conditional independence.

  16. The re-identification risk of Canadians from longitudinal demographics

    PubMed Central

    2011-01-01

    Background The public is less willing to allow their personal health information to be disclosed for research purposes if they do not trust researchers and how researchers manage their data. However, the public is more comfortable with their data being used for research if the risk of re-identification is low. There are few studies on the risk of re-identification of Canadians from their basic demographics, and no studies on their risk from their longitudinal data. Our objective was to estimate the risk of re-identification from the basic cross-sectional and longitudinal demographics of Canadians. Methods Uniqueness is a common measure of re-identification risk. Demographic data on a 25% random sample of the population of Montreal were analyzed to estimate population uniqueness on postal code, date of birth, and gender as well as their generalizations, for periods ranging from 1 year to 11 years. Results Almost 98% of the population was unique on full postal code, date of birth and gender: these three variables are effectively a unique identifier for Montrealers. Uniqueness increased for longitudinal data. Considerable generalization was required to reach acceptably low uniqueness levels, especially for longitudinal data. Detailed guidelines and disclosure policies on how to ensure that the re-identification risk is low are provided. Conclusions A large percentage of Montreal residents are unique on basic demographics. For non-longitudinal data sets, the three character postal code, gender, and month/year of birth represent sufficiently low re-identification risk. Data custodians need to generalize their demographic information further for longitudinal data sets. PMID:21696636

  17. Making use of longitudinal information in pattern recognition

    PubMed Central

    Lythgoe, David J.; Williams, Steven C.R.; Jokisch, Martha; Mönninghoff, Christoph; Streffer, Johannes; Jöckel, Karl‐Heinz; Weimar, Christian; Marquand, Andre F.

    2016-01-01

    Abstract Longitudinal designs are widely used in medical studies as a means of observing within‐subject changes over time in groups of subjects, thereby aiming to improve sensitivity for detecting disease effects. Paralleling an increased use of such studies in neuroimaging has been the adoption of pattern recognition algorithms for making individualized predictions of disease. However, at present few pattern recognition methods exist to make full use of neuroimaging data that have been collected longitudinally, with most methods relying instead on cross‐sectional style analysis. This article presents a principal component analysis‐based feature construction method that uses longitudinal high‐dimensional data to improve predictive performance of pattern recognition algorithms. The method can be applied to data from a wide range of longitudinal study designs and permits an arbitrary number of time‐points per subject. We apply the method to two longitudinal datasets, one containing subjects with mild cognitive impairment along with healthy controls, the other with early dementia subjects and healthy controls. Across both datasets, we show improvements in predictive accuracy relative to cross‐sectional classifiers for discriminating disease subjects from healthy controls on the basis of whole‐brain structural magnetic resonance image‐based voxels. In addition, we can transfer longitudinal information from one set of subjects to make disease predictions in another set of subjects. The proposed method is simple and, as a feature construction method, flexible with respect to the choice of classifier and image registration algorithm. Hum Brain Mapp 37:4385–4404, 2016. © 2016 Wiley Periodicals, Inc. PMID:27451934

  18. Longitudinal cerebral blood flow and amyloid deposition: an emerging pattern?

    PubMed Central

    Sojkova, Jitka; Beason-Held, Lori; Zhou, Yun; An, Yang; Kraut, Michael A; Ye, Weigo; Ferrucci, Luigi; Mathis, Chester A; Klunk, William E; Wong, Dean F; Resnick, Susan M

    2008-01-01

    Although cerebral amyloid deposition may precede cognitive impairment by decades, the relationship between amyloid deposition and longitudinal change in neuronal function has not been studied. The aim of this paper is to determine whether nondemented individuals with high and low amyloid burden show different patterns of longitudinal regional cerebral blood flow (rCBF) changes in the years preceding measurement of amyloid deposition. Methods Twenty-eight nondemented participants (mean (SD) age at [11C] PIB 82.5(4.8) yrs; 6 mildly impaired) from the Baltimore Longitudinal Study of Aging underwent yearly resting-state [15O]H2O PET scans for up to 8 years. [11C]PIB images of amyloid deposition were acquired on average 10.8(0.8) years after the first CBF scan. [11C]PIB distribution volume ratios (DVR) of regions of interest were estimated by fitting a reference tissue model to the measured time activity curves. Based on mean cortical DVR, participants were divided into high and low [11C]PIB retention groups. Differences in longitudinal rCBF changes between high and low [11C]PIB groups were investigated by voxel-based analysis. Results Longitudinal rCBF changes differed significantly between high (n=10) and low (n=18) [11C]PIB groups (p<=0.001). Greater longitudinal decreases in rCBF in the high [11C]PIB group were seen in right anterior/mid cingulate, right supramarginal gyrus, left thalamus and midbrain bilaterally relative to the low group. Greater increases in rCBF over time in the high [11C]PIB group were found in left medial and inferior frontal gyri, right precuneus, left inferior parietal lobule, and the left postcentral gyrus. Conclusion In this group of nondemented older adults, those with high [11C]PIB show greater longitudinal declines in rCBF in certain areas, representing regions with greater decrements in neuronal function. Greater longitudinal increases in rCBF are also observed in those with higher amyloid load and may represent an attempt to preserve

  19. A Simple, Low Cost Longitudinal Phase Space Diagnostic

    SciTech Connect

    Bertsche, Kirk; Emma, Paul; Shevchenko, Oleg; /Novosibirsk, IYF

    2009-05-15

    For proper operation of the LCLS [1] x-ray free-electron laser (FEL), and other similar machines, measurement and control of the electron bunch longitudinal phase space is critical. The LCLS accelerator includes two bunch compressor chicanes to magnify the peak current. These magnetic chicanes can generate significant coherent synchrotron radiation (CSR), which can distort the phase space distribution. We propose a diagnostic scheme by exciting a weak skew quadrupole at an energy-chirped, high dispersion point in the first LCLS bunch compressor (BC1) to reconstruct longitudinal phase space on an OTR screen after BC1, allowing a time-resolved characterization of CSR effects.

  20. Ossification of the posterior longitudinal ligament: a case report

    PubMed Central

    Aker, PD; O’Connor, SM; Mior, SA; Beauchemin, D

    1989-01-01

    Ossification of the posterior longitudinal ligament (OPLL) has recently been recognized as a clinical entity. It is a rare condition, having a higher incidence in the Japanese population. It is characterized by hyperplasia of cartilage cells with eventual endochondral ossification of the posterior longitudinal ligament. The radiographic signs are characteristic and consist of a linear band of ossified tissue along the posterior margin of the vertebral body. OPLL can be associated with mild to serious neurological complications due to spinal cord or nerve root compression, or it may be asymptomatic. This paper reviews the radiological, clinical and therapeutic aspects of this rare condition. ImagesFigures 1 and 2Figures 3 and 4

  1. Longitudinal W boson scattering in a light scalar top scenario

    NASA Astrophysics Data System (ADS)

    Ishiwata, Koji; Yonekura, Yuki

    2017-07-01

    Scalar tops in the supersymmetric model affect the potential of the standard model-like Higgs at the quantum level. In light of the equivalence theorem, the deviation of the potential from the standard model can be traced by longitudinal gauge bosons. In this work, high-energy longitudinal W boson scattering is studied in a TeV-scale scalar top scenario. O (1 - 10 %) deviation from the standard model prediction in the differential cross section is found, depending on whether the observed Higgs mass is explained only by scalar tops or by additional contributions at a higher scale.

  2. Residuals analysis of the generalized linear models for longitudinal data.

    PubMed

    Chang, Y C

    2000-05-30

    The generalized estimation equation (GEE) method, one of the generalized linear models for longitudinal data, has been used widely in medical research. However, the related sensitivity analysis problem has not been explored intensively. One of the possible reasons for this was due to the correlated structure within the same subject. We showed that the conventional residuals plots for model diagnosis in longitudinal data could mislead a researcher into trusting the fitted model. A non-parametric method, named the Wald-Wolfowitz run test, was proposed to check the residuals plots both quantitatively and graphically. The rationale proposedin this paper is well illustrated with two real clinical studies in Taiwan.

  3. Longitudinal phase space experiments on the ELSA photoinjector

    SciTech Connect

    Dowell, D.H.; Joly, S.; Brion, J.P. de

    1995-12-31

    The excellent beam quality produced by RF photocathode injectors is well established, andhas been verified by numerous measurements of the transverse emittance. However, there are few experimental determinations of the longitudinal phase space. This paper reports on experiments performed at the ELSA FEL facility to emasure the longitudinal phase space distribution at the exit of the 144 MHz photoinjector cavity. Phase spaces were determined by the analysis of beam energy spectra and pulse shapes at 17.5 MeV for micropulse charges between 0.5 and 5 nC.

  4. Analysis and prediction of longitudinal stability of airplanes

    NASA Technical Reports Server (NTRS)

    Gilruth, R R; White, M D

    1941-01-01

    An analysis has been made of the longitudinal stability characteristics of 15 airplanes as determined in flight. In the correlation of satisfactory and unsatisfactory characteristics with determined values, the derivative that expresses the ratio of static-restoring moments to elevator-control moments was found to represent most nearly the stability characteristics appreciated by the pilots. The analysis was extended to study the effects of various design features on the observed stability characteristics. Design charts and data are included that show the effects on longitudinal stability of relative positions of wing and tail, fuselage size and location, engine nacelles, and horizontal-tail arrangements.

  5. Estudo de não gaussianidade nas anisotropias da RCF medidas Wmap

    NASA Astrophysics Data System (ADS)

    Andrade, A. P. A.; Wuensche, C. A.; Ribeiro, A. L. B.

    2003-08-01

    A investigação do campo de flutuações da Radiação Cósmica de Fundo (RCF) pode oferecer um importante teste para os modelos cosmológicos que descrevem a origem e a evolução das flutuações primordiais. De um lado, apresenta-se o modelo inflacionário que prevê um espectro de flutuações adiabáticas distribuídas segundo uma gaussiana e, de outro, os modelos de defeitos topológicos (dentre outros) que descrevem um mecanismo para a geração de flutuações de isocurvatura que obedecem a uma distribuição não gaussiana. Este trabalho tem como objetivo caracterizar traços do modelo não gaussiano de campo misto (entre flutuações adiabáticas e de isocurvatura) nos mapas do Wilkinson Microwave Anisotropy Probe (WMAP). Simulações das anisotropias da RCF no contexto de mistura indicam traços marcantes na distribuição das flutuações de temperatura, mesmo quando consideradas pequenas contribuições do campo de isocurvatura (da ordem de 0.001). O efeito da mistura entre os campos resulta na transferência de potência de flutuações em escalas angulares intermediárias para flutuações em pequenas escalas angulares. Este efeito pode ser caracterizado pela relação entre as amplitudes dos primeiros picos acústicos no espectro de potência da RCF. Neste trabalho, investigamos a contribuição do campo de isocurvatura, no contexto de mistura, sobre as observações recentes da RCF realizadas pelo WMAP. As previsões do modelo de campo misto, uma vez confrontadas com as observações em pequenas escalas angulares, podem ajudar a revelar a natureza das flutuações primordiais.

  6. Separation-Individuation of Late Adolescents : A Longitudinal Study

    ERIC Educational Resources Information Center

    Aslan, Sevda; Gelbal, Selahattin

    2016-01-01

    The aim of this study was to demonstrate the change in separation-individuation between late adolescents in the first, second, third and fourth year of higher education. The study sample used for this longitudinal study consisted of 148 students attending class studies, computer education and science education departments of Kirikkale University.…

  7. A Longitudinal Study of Retirement in Older Male Veterans

    ERIC Educational Resources Information Center

    Schnurr, Paula P.; Lunney, Carole A.; Sengupta, Anjana; Spiro, Avron

    2005-01-01

    In this study, the authors examined the effect of retirement on psychological and physical symptoms in 404 older male veterans who were taking part in an ongoing longitudinal study. Hierarchical linear modeling was used to analyze symptom trajectories from preretirement, peri-retirement, and postretirement periods in veterans with either lifetime…

  8. Evaluating Digital Libraries: A Longitudinal and Multifaceted View.

    ERIC Educational Resources Information Center

    Marchionini, Gary

    2000-01-01

    The Perseus Digital Library (PDL), under continuous development since 1987, is one of the primary digital resources for the humanities. A summary of the PDL genesis and current status is given and the multifaceted and longitudinal evaluation effort is described. A brief synthesis of results is provided and reflections on the evaluation along with…

  9. 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…

  10. The Longitudinal Association between Oppositional and Depressive Symptoms across Childhood

    ERIC Educational Resources Information Center

    Boylan, Khrista; Georgiades, Katholiki; Szatmari, Peter

    2010-01-01

    Objective: Symptoms of oppositional defiant disorder (ODD) and depression show high rates of co-occurrence, both cross-sectionally and longitudinally. This study examines the extent to which variation in oppositional symptoms predict, variation in depressive symptoms over time, accounting for co-occurring depressive symptoms and measurement error.…

  11. A Longitudinal Assessment of the Victim-Offender Overlap

    ERIC Educational Resources Information Center

    Jennings, Wesley G.; Higgins, George E.; Tewksbury, Richard; Gover, Angela R.; Piquero, Alex R.

    2010-01-01

    Although research has established an offending/victimization overlap and that offenders and victims share similar characteristics, much less work has examined the longitudinal sequencing of victimization and offending in the same developmental period and whether key risk/protective factors significantly distinguish both offenders and victims. This…

  12. A Longitudinal Study of Accounting Students' Ethical Judgement Making Ability

    ERIC Educational Resources Information Center

    Mohamed Saat, Maisarah; Porter, Stacey; Woodbine, Gordon

    2012-01-01

    This paper reports the effect of a moral education programme on the ethical judgement making ability of university students. The programme comprises two forms of intervention: a dedicated ethics course and subsequent practical training. A total of 113 accounting students from six Malaysian universities participated in a longitudinal study…

  13. A Longitudinal Study of Relational and Physical Aggression in Preschool

    ERIC Educational Resources Information Center

    Crick, Nicki R.; Ostrov, Jamie M.; Burr, Jean E.; Cullerton-Sen, Crystal; Jansen-Yeh, Elizabeth; Ralston, Peter

    2006-01-01

    To understand the development of relational aggression during early childhood, 91 girls and boys ("M" age=39.0; "SD"=7.6 months) and their teachers participated in an 18-month longitudinal study. Children were observed for relational and physical aggression during free play in four time periods. Individually administered interviews were conducted…

  14. Longitudinal Effects of Domestic Violence on Employment and Welfare Outcomes

    ERIC Educational Resources Information Center

    Lindhorst, Taryn; Oxford, Monica; Gillmore, Mary Rogers

    2007-01-01

    This study uses longitudinal data spanning 13 years from a study of 234 adolescent mothers to evaluate the effects of cumulative domestic violence on employment and welfare use before and after welfare reform. Domestic violence increased the odds of unemployment after welfare reform, but not before; domestic violence had no effect on welfare use…

  15. Consistency and Development of Prosocial Dispositions: A Longitudinal Study.

    ERIC Educational Resources Information Center

    Eisenberg, Nancy; Guthrie, Ivanna K.; Murphy, Bridget C.; Shepard, Stephanie A.; Cumberland, Amanda; Carol, Gustavo

    1999-01-01

    Examined consistency in prosocial dispositions, using longitudinal data from preschool through early adulthood. Found that spontaneous prosocial behavior observed in preschools predicted actual prosocial behavior, other- and self-reported prosocial behavior, self-reported sympathy, and perspective taking in childhood to early adulthood. Prosocial…

  16. Longitudinal wave motion in width-constrained auxetic plates

    NASA Astrophysics Data System (ADS)

    Lim, Teik-Cheng

    2016-05-01

    This paper investigates the longitudinal wave velocity in auxetic plates in comparison to conventional ones, in which the plate is constrained from motion in the width direction. By taking into account the thickness change of the plate and its corresponding change in density, the developed wave velocity is casted not only as a function of Young’s modulus and density, but also in terms of Poisson’s ratio and longitudinal strain. Results show that density and thickness variations compensate for one another when the Poisson’s ratio is positive, but add up when the Poisson’s ratio is negative. Results also reveal that the classical model of longitudinal wave velocity for the plate is accurate when the Poisson’s ratio is about 1/3; at this Poisson’s ratio the influence from density and thickness variations cancel each other. Comparison between the current corrected model and the density-corrected Rayleigh-Lamb model reveals a number of consistent trends, while the discrepancies are elucidated. If the plate material possesses a negative Poisson’s ratio, the deviation of the actual wave velocity from the classical model becomes significant; auxeticity suppresses and enhances the wave velocity in compressive and tensile impacts, respectively. Hence the use of the corrected model is proposed when predicting longitudinal waves in width-constrained auxetic plates, and auxetic materials can be harnessed for effectively controlling wave velocities in thin-walled structures.

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

    ERIC Educational Resources Information Center

    Russo, Silvia; Roccato, Michele; Vieno, Alessio

    2013-01-01

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

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

    ERIC Educational Resources Information Center

    Salthouse, Timothy A.

    2013-01-01

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

  19. 9. Photograph of a line drawing. SHEET 9, LONGITUDINAL SECTION ...

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

    9. Photograph of a line drawing. SHEET 9, LONGITUDINAL SECTION ON LINE AA; 9-16-1940. Assembly Building for Tank Plant for the Chrysler Corporation, Macomb County, Michigan. Delineator: E.B. - Detroit Arsenal, 6501 East Eleven Mile Road, Warren, Macomb County, MI

  20. Longitudinal Bidirectional Relations between Adolescents' Sympathy and Prosocial Behavior

    ERIC Educational Resources Information Center

    Carlo, Gustavo; Padilla-Walker, Laura M.; Nielson, Matthew G.

    2015-01-01

    Despite the importance of understanding sympathy and prosocial behaviors, research on the development of these tendencies in adolescence remains relatively sparse. In the present study, we examined age trends and bidirectional longitudinal relations in sympathy and prosocial behaviors across early to middle adolescents. Participants were 500…

  1. Two-Method Planned Missing Designs for Longitudinal Research

    ERIC Educational Resources Information Center

    Garnier-Villarreal, Mauricio; Rhemtulla, Mijke; Little, Todd D.

    2014-01-01

    We examine longitudinal extensions of the two-method measurement design, which uses planned missingness to optimize cost-efficiency and validity of hard-to-measure constructs. These designs use a combination of two measures: a "gold standard" that is highly valid but expensive to administer, and an inexpensive (e.g., survey-based)…

  2. LONGITUDINAL OSCILLATIONS IN DENSITY STRATIFIED AND EXPANDING SOLAR WAVEGUIDES

    SciTech Connect

    Luna-Cardozo, M.; Verth, G.; Erdelyi, R. E-mail: robertus@sheffield.ac.uk

    2012-04-01

    Waves and oscillations can provide vital information about the internal structure of waveguides in which they propagate. Here, we analytically investigate the effects of density and magnetic stratification on linear longitudinal magnetohydrodynamic (MHD) waves. The focus of this paper is to study the eigenmodes of these oscillations. It is our specific aim to understand what happens to these MHD waves generated in flux tubes with non-constant (e.g., expanding or magnetic bottle) cross-sectional area and density variations. The governing equation of the longitudinal mode is derived and solved analytically and numerically. In particular, the limit of the thin flux tube approximation is examined. The general solution describing the slow longitudinal MHD waves in an expanding magnetic flux tube with constant density is found. Longitudinal MHD waves in density stratified loops with constant magnetic field are also analyzed. From analytical solutions, the frequency ratio of the first overtone and fundamental mode is investigated in stratified waveguides. For small expansion, a linear dependence between the frequency ratio and the expansion factor is found. From numerical calculations it was found that the frequency ratio strongly depends on the density profile chosen and, in general, the numerical results are in agreement with the analytical results. The relevance of these results for solar magneto-seismology is discussed.

  3. 14 CFR 27.173 - Static longitudinal stability.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Static longitudinal stability. 27.173 Section 27.173 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Flight Flight Characteristics § 27.173...

  4. 14 CFR 25.173 - Static longitudinal stability.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Static longitudinal stability. 25.173 Section 25.173 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Flight Stability § 25.173...

  5. 14 CFR 27.173 - Static longitudinal stability.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Static longitudinal stability. 27.173 Section 27.173 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Flight Flight Characteristics § 27.173...

  6. 14 CFR 25.173 - Static longitudinal stability.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Static longitudinal stability. 25.173 Section 25.173 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Flight Stability § 25.173...

  7. 14 CFR 27.173 - Static longitudinal stability.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Static longitudinal stability. 27.173 Section 27.173 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Flight Flight Characteristics § 27.173...

  8. 14 CFR 27.173 - Static longitudinal stability.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Static longitudinal stability. 27.173 Section 27.173 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Flight Flight Characteristics § 27.173...

  9. 14 CFR 25.173 - Static longitudinal stability.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Static longitudinal stability. 25.173 Section 25.173 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Flight Stability § 25.173...

  10. 14 CFR 25.173 - Static longitudinal stability.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Static longitudinal stability. 25.173 Section 25.173 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Flight Stability § 25.173...

  11. 14 CFR 27.173 - Static longitudinal stability.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Static longitudinal stability. 27.173 Section 27.173 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Flight Flight Characteristics § 27.173...

  12. 14 CFR 25.173 - Static longitudinal stability.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Static longitudinal stability. 25.173 Section 25.173 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Flight Stability § 25.173...

  13. Sensitivity Analysis of Mixed Models for Incomplete Longitudinal Data

    ERIC Educational Resources Information Center

    Xu, Shu; Blozis, Shelley A.

    2011-01-01

    Mixed models are used for the analysis of data measured over time to study population-level change and individual differences in change characteristics. Linear and nonlinear functions may be used to describe a longitudinal response, individuals need not be observed at the same time points, and missing data, assumed to be missing at random (MAR),…

  14. A Longitudinal Analysis of Television Advertising Effects on Adolescents.

    ERIC Educational Resources Information Center

    Moore, Roy L.; Moschis, George P.

    A longitudinal study examined both the short term and the long term effects of television advertising on the development of adolescents' consumption-related orientations. Questionnaires were administered to 556 adolescents in a number of schools in a southern state; a second wave of questionnaires was administered to a subsample of 230 of these…

  15. Minor Delinquency and Immigration: A Longitudinal Study among Male Adolescents

    ERIC Educational Resources Information Center

    Titzmann, Peter F.; Silbereisen, Rainer K.; Mesch, Gustavo

    2014-01-01

    On the basis of general theories of delinquency and the specific situation of immigrants, this longitudinal study investigated predictors of initial levels and rates of change in delinquency among 188 male ethnic German Diaspora immigrants from the former Soviet Union (FSU) in Germany, 237 male native German adolescents, and 182 male Jewish…

  16. Social Learning in a Longitudinal Integrated Clinical Placement

    ERIC Educational Resources Information Center

    Roberts, Chris; Daly, Michele; Held, Fabian; Lyle, David

    2017-01-01

    Recent research has demonstrated that longitudinal integrated placements (LICs) are an alternative mode of clinical education to traditional placements. Extended student engagement in community settings provide the advantages of educational continuity as well as increased service provision in underserved areas. Developing and maintaining LICs…

  17. Longitudinal Study of Low and High Achievers in Early Mathematics

    ERIC Educational Resources Information Center

    Navarro, Jose I.; Aguilar, Manuel; Marchena, Esperanza; Ruiz, Gonzalo; Menacho, Inmaculada; Van Luit, Johannes E. H.

    2012-01-01

    Background: Longitudinal studies allow us to identify, which specific maths skills are weak in young children, and whether there is a continuing weakness in these areas throughout their school years. Aims: This 2-year study investigated whether certain socio-demographic variables affect early mathematical competency in children aged 5-7 years.…

  18. Beyond Longitudinal Data: Causes, Consequences, Changes, and Continuity.

    ERIC Educational Resources Information Center

    Rutter, Michael

    1994-01-01

    Addresses strategies needed in using longitudinal data on psychopathology to test cause-and-effect relationships, including natural experiments, testing of competing hypotheses on mechanisms, study of reversal effects, multiple replications in different circumstances, use of designs to dissociate possible mechanisms, testing for dose-response…

  19. 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…

  20. A Longitudinal Study of Judge Leniency and Consistency.

    ERIC Educational Resources Information Center

    Lunz, Mary E.; O'Neill, Thomas R.

    This retrospective longitudinal study was designed to show grading leniency patterns of judges within and across clinical examination administrations. Data from 17 different administrations of the histology examination of the American Society of Clinical Pathologists over 10 years were studied. Over the 10 years there were 4,683 candidates and 57…